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  • 1.
    Barro-Soria, Rene
    et al.
    University of Miami, FL 33136 USA.
    Liin, Sara
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Larsson, H. Peter
    University of Miami, FL 33136 USA.
    Specificity of M-channel activators: binding or effect?2017In: Journal of Physiology, ISSN 0022-3751, E-ISSN 1469-7793, Vol. 595, no 3, p. 605-606Article in journal (Other academic)
    Abstract [en]

    n/a

  • 2.
    Barro-Soria, Rene
    et al.
    Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL, USA.
    Liin, Sara
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Larsson, H. Peter
    Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL, USA.
    Using fluorescence to understand beta subunit-Na-V channel interactions2017In: The Journal of General Physiology, ISSN 0022-1295, E-ISSN 1540-7748, Vol. 149, no 8, p. 757-762Article in journal (Other academic)
    Abstract [en]

    n/a

  • 3.
    Barro-Soria, Rene
    et al.
    University of Miami, FL 33136 USA.
    Ramentol, Rosamary
    University of Miami, FL 33136 USA.
    Liin, Sara
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. University of Miami, FL 33136 USA.
    Perez, Marta E.
    University of Miami, FL 33136 USA.
    Kass, Robert S.
    Columbia University, NY 10032 USA.
    Larsson, H. Peter
    University of Miami, FL 33136 USA.
    KCNE1 and KCNE3 modulate KCNQ1 channels by affecting different gating transitions2017In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 114, no 35, p. E7367-E7376Article in journal (Refereed)
    Abstract [en]

    KCNE beta-subunits assemble with and modulate the properties of voltage-gated K+ channels. In the heart, KCNE1 associates with the alpha-subunit KCNQ1 to generate the slowly activating, voltage-dependent potassium current (IKs) in the heart that controls the repolarization phase of cardiac action potentials. By contrast, in epithelial cells from the colon, stomach, and kidney, KCNE3 coassembles with KCNQ1 to form K+ channels that are voltage-independent K+ channels in the physiological voltage range and important for controlling water and salt secretion and absorption. How KCNE1 and KCNE3 subunits modify KCNQ1 channel gating so differently is largely unknown. Here, we use voltage clamp fluorometry to determine how KCNE1 and KCNE3 affect the voltage sensor and the gate of KCNQ1. By separating S4 movement and gate opening by mutations or phosphatidylinositol 4,5-bisphosphate depletion, we show that KCNE1 affects both the S4 movement and the gate, whereas KCNE3 affects the S4 movement and only affects the gate in KCNQ1 if an intact S4-to-gate coupling is present. Further, we show that a triple mutation in the middle of the transmembrane (TM) segment of KCNE3 introduces KCNE1-like effects on the second S4 movement and the gate. In addition, we show that differences in two residues at the external end of the KCNE TM segments underlie differences in the effects of the different KCNEs on the first S4 movement and the voltage sensor-to-gate coupling.

  • 4.
    Blomqvist, Anders
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Engblom, David
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Neural Mechanisms of Inflammation-Induced Fever2018In: The Neuroscientist, ISSN 1073-8584, E-ISSN 1089-4098, Vol. 24, no 4, p. 381-399Article, review/survey (Refereed)
    Abstract [en]

    Fever is a common symptom of infectious and inflammatory disease. It is well-established that prostaglandin E-2 is the final mediator of fever, which by binding to its EP3 receptor subtype in the preoptic hypothalamus initiates thermogenesis. Here, we review the different hypotheses on how the presence of peripherally released pyrogenic substances can be signaled to the brain to elicit fever. We conclude that there is unequivocal evidence for a humoral signaling pathway by which proinflammatory cytokines, through their binding to receptors on brain endothelial cells, evoke fever by eliciting prostaglandin E-2 synthesis in these cells. The evidence for a role for other signaling routes for fever, such as signaling via circumventricular organs and peripheral nerves, as well as transfer into the brain of peripherally synthesized prostaglandin E-2 are yet far from conclusive. We also review the efferent limb of the pyrogenic pathways. We conclude that it is well established that prostaglandin E-2 binding in the preoptic hypothalamus produces fever by disinhibition of presympathetic neurons in the brain stem, but there is yet little understanding of the mechanisms by which factors such as nutritional status and ambient temperature shape the response to the peripheral immune challenge.

  • 5.
    Borner, Tito
    et al.
    University of Zurich, Switzerland.
    Arnold, Myrtha
    Swiss Federal Institute Technology, Switzerland.
    Ruud, Johan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Breit, Samuel N.
    University of New South Wales, Australia.
    Langhans, Wolfgang
    University of Zurich, Switzerland; Swiss Federal Institute Technology, Switzerland.
    Lutz, Thomas A.
    University of Zurich, Switzerland.
    Blomqvist, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Riediger, Thomas
    University of Zurich, Switzerland.
    Anorexia-cachexia syndrome in hepatoma tumour-bearing rats requires the area postrema but not vagal afferents and is paralleled by increased MIC-1/GDF152017In: Journal of Cachexia, Sarcopenia and Muscle, ISSN 2190-5991, E-ISSN 2190-6009, Vol. 8, no 3, p. 417-427Article in journal (Refereed)
    Abstract [en]

    Background The cancer-anorexia-cachexia syndrome (CACS) negatively affects survival and therapy success in cancer patients. Inflammatory mediators and tumour-derived factors are thought to play an important role in the aetiology of CACS. However, the central and peripheral mechanisms contributing to CACS are insufficiently understood. The area postrema (AP) and the nucleus tractus solitarii are two important brainstem centres for the control of eating during acute sickness conditions. Recently, the tumour-derived macrophage inhibitory cytokine-1 (MIC-1) emerged as a possible mediator of cancer anorexia because lesions of these brainstem areas attenuated the anorectic effect of exogenous MIC-1 in mice. Methods Using a rat hepatoma tumour model, we examined the roles of the AP and of vagal afferents in the mediation of CACS. Specifically, we investigated whether a lesion of the AP (APX) or subdiaphragmatic vagal deafferentation (SDA) attenuate anorexia, body weight, muscle, and fat loss. Moreover, we analysed MIC-1 levels in this tumour model and their correlation with tumour size and the severity of the anorectic response. Results In tumour-bearing sham-operated animals mean daily food intake significantly decreased. The anorectic response was paralleled by a significant loss of body weight and muscle mass. APX rats were protected against anorexia, body weight loss, and muscle atrophy after tumour induction. In contrast, subdiaphragmatic vagal deafferentation did not attenuate cancer-induced anorexia or body weight loss. Tumour-bearing rats had substantially increased MIC-1 levels, which positively correlated with tumour size and cancer progression and negatively correlated with food intake. Conclusions These findings demonstrate the importance of the AP in the mediation of cancer-dependent anorexia and body weight loss and support a pathological role of MIC-1 as a tumour-derived factor mediating CACS, possibly via an AP-dependent action.

  • 6.
    Bruhn, H.
    et al.
    Cty Hosp Ryhov, Sweden.
    Strandeus, M.
    Cty Hosp Ryhov, Sweden.
    Milos, Peter
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Neurosurgery.
    Hallbeck, Martin
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Vrethem, Magnus
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Local Health Care Services in Central Östergötland, Department of Neurology.
    Lind, Jonas
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Cty Hosp Ryhov, Sweden.
    Improved survival of Swedish glioblastoma patients treated according to Stupp2018In: Acta Neurologica Scandinavica, ISSN 0001-6314, E-ISSN 1600-0404, Vol. 138, no 4, p. 332-337Article in journal (Refereed)
    Abstract [en]

    ObjectivesThe median survival in glioblastoma (GBM) patients used to be less than 1year. Surgical removal of the tumor with subsequent concomitant radiation/temozolomide (the Stupp regimen) has been shown to prolong survival. The Stupp protocol was implemented in the county of Jonkoping in 2006. The purpose of this study was to examine if the Stupp treatment has prolonged overall survival, in an unselected patient cohort with histologically verified GBM. Material and MethodThis study includes all patients from the county of Jonkoping, with a diagnosis of GBM from January 2001 to December 2012. Patients were divided into 2 cohorts, 2001-2005 and 2006-2012, that is before and after implementation of the Stupp regimen. By reviewing the medical case notes, the dates of the histological diagnosis and of death were identified. The median and mean overall survival and Kaplan-Meier survival analysis were calculated and compared between the 2 cohorts. ResultsThe mean survival was 110days longer in the cohort treated according to the Stupp regimen. Four patients in the 2006-2012 cohort and 1 patient in the 2001-2005 cohort are still alive. When comparing survival in patients with radical surgery vs biopsy, those that underwent radical surgery survived longer. The significance was slightly greater in the 2001-2005 cohort (mean 163 vs 344days, Pamp;lt;.001) than in the 2006-2012 cohort (mean 220 vs 397days, P=.02). ConclusionSurvival significantly improved after the implementation of the Stupp regimen in the study region of Sweden.

  • 7.
    Capitanio, Arrigo
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Clinical pathology.
    Dina, R. E.
    Imperial Coll NHS Trust, England.
    Treanor, Darren
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Leeds Teaching Hosp NHS Trust, England.
    Digital cytology: A short review of technical and methodological approaches and applications2018In: Cytopathology, ISSN 0956-5507, E-ISSN 1365-2303, Vol. 29, no 4, p. 317-325Article, review/survey (Refereed)
    Abstract [en]

    The recent years have been characterised by a rapid development of whole slide imaging (WSI) especially in its applications to histology. The application of WSI technology to cytology is less common because of technological problems related to the three-dimensional nature of cytology preparations (which requires capturing of z-stack information, with an increase in file size and usability issues in viewing cytological preparations). The aim of this study is to provide a review of the literature on the use of digital cytology and provide an overview of cytological applications of WSI in current practice as well as identifying areas for future development.

  • 8.
    Ciganovic, Nikola
    et al.
    Imperial Coll London, England.
    Warren, Rebecca L.
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Keceli, Batu
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Jacob, Stefan
    Karolinska Inst, Sweden.
    Fridberger, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Reichenbach, Tobias
    Imperial Coll London, England; Univ Calif Santa Barbara, CA 93106 USA.
    Static length changes of cochlear outer hair cells can tune low-frequency hearing2018In: PloS Computational Biology, ISSN 1553-734X, E-ISSN 1553-7358, Vol. 14, no 1, article id e1005936Article in journal (Refereed)
    Abstract [en]

    The cochlea not only transduces sound-induced vibration into neural spikes, it also amplifies weak sound to boost its detection. Actuators of this active process are sensory outer hair cells in the organ of Corti, whereas the inner hair cells transduce the resulting motion into electric signals that propagate via the auditory nerve to the brain. However, how the outer hair cells modulate the stimulus to the inner hair cells remains unclear. Here, we combine theoretical modeling and experimental measurements near the cochlear apex to study the way in which length changes of the outer hair cells deform the organ of Corti. We develop a geometry-based kinematic model of the apical organ of Corti that reproduces salient, yet counter-intuitive features of the organs motion. Our analysis further uncovers a mechanism by which a static length change of the outer hair cells can sensitively tune the signal transmitted to the sensory inner hair cells. When the outer hair cells are in an elongated state, stimulation of inner hair cells is largely inhibited, whereas outer hair cell contraction leads to a substantial enhancement of sound-evoked motion near the hair bundles. This novel mechanism for regulating the sensitivity of the hearing organ applies to the low frequencies that are most important for the perception of speech and music. We suggest that the proposed mechanism might underlie frequency discrimination at low auditory frequencies, as well as our ability to selectively attend auditory signals in noisy surroundings.

  • 9.
    Dominguez-Perez, Dany
    et al.
    Univ Porto, Portugal.
    Campos, Alexandre
    Univ Porto, Portugal.
    Rodriguez, Armando Alexei
    Hanover Med Sch MHH, Germany.
    Turkina, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Ribeiro, Tiago
    Univ Porto, Portugal.
    Osorio, Hugo
    Univ Porto, Portugal.
    Vasconcelos, Vitor
    Univ Porto, Portugal; Univ Porto, Portugal.
    Antunes, Agostinho
    Univ Porto, Portugal.
    Proteomic Analyses of the Unexplored Sea Anemone Bunodactis verrucosa2018In: Marine Drugs, ISSN 1660-3397, E-ISSN 1660-3397, Vol. 16, no 2, article id 42Article in journal (Refereed)
    Abstract [en]

    Cnidarian toxic products, particularly peptide toxins, constitute a promising target for biomedicine research. Indeed, cnidarians are considered as the largest phylum of generally toxic animals. However, research on peptides and toxins of sea anemones is still limited. Moreover, most of the toxins from sea anemones have been discovered by classical purification approaches. Recently, high-throughput methodologies have been used for this purpose but in other Phyla. Hence, the present work was focused on the proteomic analyses of whole-body extract from the unexplored sea anemone Bunodactis verrucosa. The proteomic analyses applied were based on two methods: two-dimensional gel electrophoresis combined with MALDI-TOF/TOF and shotgun proteomic approach. In total, 413 proteins were identified, but only eight proteins were identified from gel-based analyses. Such proteins are mainly involved in basal metabolism and biosynthesis of antibiotics as the most relevant pathways. In addition, some putative toxins including metalloproteinases and neurotoxins were also identified. These findings reinforce the significance of the production of antimicrobial compounds and toxins by sea anemones, which play a significant role in defense and feeding. In general, the present study provides the first proteome map of the sea anemone B. verrucosa stablishing a reference for future studies in the discovery of new compounds.

  • 10.
    Elinder, Fredrik
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Börjesson, Sara I.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Actions and Mechanisms of Polyunsaturated Fatty Acids on Voltage-Gated Ion Channels2017In: Frontiers in Physiology, ISSN 1664-042X, E-ISSN 1664-042X, Vol. 8, article id 43Article, review/survey (Refereed)
    Abstract [en]

    Polyunsaturated fatty acids (PUFAs) act on most ion channels, thereby having significant physiological and pharmacological effects. In this review we summarize data from numerous PUFAs on voltage-gated ion channels containing one or several voltage-sensor domains, such as voltage-gated sodium (NaV), potassium (KV), calcium (CaV), and proton (HV) channels, as well as calcium-activated potassium (KCa), and transient receptor potential (TRP) channels. Some effects of fatty acids appear to be channel specific, whereas others seem to be more general. Common features for the fatty acids to act on the ion channels are at least two double bonds in cis geometry and a charged carboxyl group. In total we identify and label five different sites for the PUFAs. PUFA site 1: The intracellular cavity. Binding of PUFA reduces the current, sometimes as a time-dependent block, inducing an apparent inactivation. PUFA site 2: The extracellular entrance to the pore. Binding leads to a block of the channel. PUFA site 3: The intracellular gate. Binding to this site can bend the gate open and increase the current. PUFA site 4: The interface between the extracellular leaflet of the lipid bilayer and the voltage-sensor domain. Binding to this site leads to an opening of the channel via an electrostatic attraction between the negatively charged PUFA and the positively charged voltage sensor. PUFA site 5: The interface between the extracellular leaflet of the lipid bilayer and the pore domain. Binding to this site affects slow inactivation. This mapping of functional PUFA sites can form the basis for physiological and pharmacological modifications of voltage-gated ion channels.

  • 11.
    Elyas, Eli
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. CRUK, England; Institute Cancer Research, England; Institute Cancer Research, England; Royal Marsden NHS Fdn Trust, England.
    Papaevangelou, Efthymia
    CRUK, England; Institute Cancer Research, England; Kings Coll London, England.
    Alles, Erwin J.
    CRUK, England; Institute Cancer Research, England; Institute Cancer Research, England; Royal Marsden NHS Fdn Trust, England; Kings Coll London, England; UCL, England.
    Erler, Janine T.
    University of Copenhagen, Denmark.
    Cox, Thomas R.
    University of New South Wales, Australia; University of New South Wales, Australia.
    Robinson, Simon P.
    CRUK, England; Institute Cancer Research, England.
    Bamber, Jeffrey C.
    CRUK, England; Institute Cancer Research, England; Institute Cancer Research, England; Royal Marsden NHS Fdn Trust, England.
    Correlation of Ultrasound Shear Wave Elastography with Pathological Analysis in a Xenografic Tumour Model2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 165Article in journal (Refereed)
    Abstract [en]

    The objective of this study was to evaluate the potential value of ultrasound (US) shear wave elastography (SWE) in assessing the relative change in elastic modulus in colorectal adenocarcinoma xenograft models in vivo and investigate any correlation with histological analysis. We sought to test whether non-invasive evaluation of tissue stiffness is indicative of pathological tumour changes and can be used to monitor therapeutic efficacy. US-SWE was performed in tumour xenografts in 15 NCr nude immunodeficient mice, which were treated with either the cytotoxic drug, Irinotecan, or saline as control. Ten tumours were imaged 48 hours post-treatment and five tumours were imaged for up to five times after treatment. All tumours were harvested for histological analysis and comparison with elasticity measurements. Elastic (Youngs) modulus prior to treatment was correlated with tumour volume (r = 0.37, p = 0.008). Irinotecan administration caused significant delay in the tumour growth (p = 0.02) when compared to control, but no significant difference in elastic modulus was detected. Histological analysis revealed a significant correlation between tumour necrosis and elastic modulus (r = -0.73, p = 0.026). SWE measurement provided complimentary information to other imaging modalities and could indicate potential changes in the mechanical properties of tumours, which in turn could be related to the stages of tumour development.

  • 12.
    Eskilsson, Anna
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Matsuwaki, Takashi
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Shionoya, Kiseko
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Mirrasekhian, Elahe
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Zajdel, Joanna
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Schwaninger, Markus
    University of Lubeck, Germany.
    Engblom, David
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Blomqvist, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Immune-Induced Fever Is Dependent on Local But Not Generalized Prostaglandin E-2 Synthesis in the Brain2017In: Journal of Neuroscience, ISSN 0270-6474, E-ISSN 1529-2401, Vol. 37, no 19, p. 5035-5044Article in journal (Refereed)
    Abstract [en]

    Fever occurs upon binding of prostaglandin E-2 (PGE(2)) to EP3 receptors in the median preoptic nucleus of the hypothalamus, but the origin of the pyrogenic PGE(2) has not been clearly determined. Here, using mice of both sexes, we examined the role of local versus generalized PGE(2) production in the brain for the febrile response. In wild-type mice and in mice with genetic deletion of the prostaglandin synthesizing enzyme cyclooxygenase-2 in the brain endothelium, generated with an inducible CreER(T2) under the Slco1c1 promoter, PGE(2) levels in the CSF were only weakly related to the magnitude of the febrile response, whereas the PGE(2) synthesizing capacity in the hypothalamus, as reflected in the levels of cyclooxygenase-2 mRNA, showed strong correlation with the immune-induced fever. Histological analysis showed that the deletion of cyclooxygenase-2 in brain endothelial cells occurred preferentially in small-and medium-sized vessels deep in the brain parenchyma, such as in the hypothalamus, whereas larger vessels, and particularly those close to the neocortical surface and in the meninges, were left unaffected, hence leaving PGE(2) synthesis largely intact in major parts of the brain while significantly reducing it in the region critical for the febrile response. Furthermore, injection of a virus vector expressing microsomal prostaglandin E synthase-1 (mPGES-1) into the median preoptic nucleus of fever-refractive mPGES-1 knock-out mice, resulted in a temperature elevation in response to LPS. We conclude that the febrile response is dependent on local release of PGE(2) onto its target neurons and not on the overall PGE(2) production in the brain.

  • 13.
    Garvin, Stina
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Oda, Husam
    Cty Hosp Ryhov, Sweden; Umea Univ, Sweden.
    Arnesson, Lars-Gunnar
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Linköping.
    Lindström, Annelie
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Shabo, Ivan
    Karolinska Inst, Sweden; Karolinska Univ Hosp, Sweden.
    Tumor cell expression of CD163 is associated to postoperative radiotherapy and poor prognosis in patients with breast cancer treated with breast-conserving surgery2018In: Journal of Cancer Research and Clinical Oncology, ISSN 0171-5216, E-ISSN 1432-1335, Vol. 144, no 7, p. 1253-1263Article in journal (Refereed)
    Abstract [en]

    Cancer cell fusion with macrophages results in highly tumorigenic hybrids that acquire genetic and phenotypic characteristics from both maternal cells. Macrophage traits, exemplified by CD163 expression, in tumor cells are associated with advanced stages and poor prognosis in breast cancer (BC). In vitro data suggest that cancer cells expressing CD163 acquire radioresistance. Tissue microarray was constructed from primary BC obtained from 83 patients treated with breast-conserving surgery, 50% having received postoperative radiotherapy (RT) and none of the patients had lymph node or distant metastasis. Immunostaining of CD163 in cancer cells and macrophage infiltration (MI) in tumor stroma were evaluated. Macrophage:MCF-7 hybrids were generated by spontaneous in vitro cell fusion. After irradiation (0, 2.5 and 5 Gy gamma-radiation), both hybrids and their maternal MCF-7 cells were examined by clonogenic survival. CD163-expression by cancer cells was significantly associated with MI and clinicopathological data. Patients with CD163-positive tumors had significantly shorter disease-free survival (DFS) after RT. In vitro generated macrophage:MCF-7 hybrids developed radioresistance and exhibited better survival and colony forming ability after radiation compared to maternal MCF-7 cancer cells. Our results suggest that macrophage phenotype in tumor cells results in radioresistance in breast cancer and shorter DFS after radiotherapy.

  • 14.
    Gustafsson Asting, Annika
    et al.
    University of Gothenburg, Sweden.
    Iresjö, Britt-Marie
    University of Gothenburg, Sweden.
    Nilsberth, Camilla
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Local Health Care Services in Central Östergötland, Department of Acute Internal Medicine and Geriatrics.
    Smedh, Ulrika
    University of Gothenburg, Sweden.
    Lundholm, Kent
    University of Gothenburg, Sweden.
    Host knockout of E-prostanoid 2 receptors reduces tumor growth and causes major alterations of gene expression in prostaglandin E2-producing tumors2017In: Oncology Letters, ISSN 1792-1074, E-ISSN 1792-1082, Vol. 13, no 1, p. 476-482Article in journal (Refereed)
    Abstract [en]

    Prostaglandin E-2 (PGE(2)) is elevated in a variety of malignant tumors and has been shown to affect several hallmarks of cancer. Accordingly, the PGE, receptor, E-prostanoid 2 (EP2), has been reported to be associated with patient survival and reduced tumor growth in EP2-knockout mice. Thus, the aim of the present study was to screen for major gene expression alterations in tumor tissue growing in EP2-knockout mice. EP2-knockout mice were bred and implanted with EP2 receptor-expressing and PGE(2)-producing epithelial-like tumors. Tumor tissue and plasma were collected and used for analyses with gene expression microarrays and multiplex enzyme-linked immunosorbent assays. Tumor growth, acute phase reactions/systemic inflammation and the expression of interleukin-6 were reduced in EP2-knockout tumor-bearing mice. Several hundreds of genes displayed major changes of expression in the tumor tissue when grown in EP2-knockout mice. Such gene alterations involved several different cellular functions, including sternness, migration and cell signaling. Besides gene expression, several long non-coding RNAs were downregulated in the tumors from the EP2-knockout mice. Overall, PGE(2) signaling via host EP2 receptors affected a large number of different genes involved in tumor progression based on signaling between host stroma and tumor cells, which caused reduced tumor growth.

  • 15.
    Gustafsson, Gabriel
    et al.
    Uppsala Univ, Sweden.
    Loov, Camilla
    Massachusetts Gen Hosp, MA 02129 USA; Harvard Med Sch, MA 02115 USA.
    Persson, Emma
    Uppsala Univ, Sweden.
    Lazaro, Diana F.
    Univ Med Ctr Gottingen, Germany.
    Takeda, Shuko
    Massachusetts Gen Hosp, MA 02129 USA; Harvard Med Sch, MA 02115 USA.
    Bergstrom, Joakim
    Uppsala Univ, Sweden.
    Erlandsson, Anna
    Uppsala Univ, Sweden.
    Sehlin, Dag
    Uppsala Univ, Sweden.
    Balaj, Leonora
    Massachusetts Gen Hosp, MA 02129 USA; Massachusetts Gen Hosp, MA 02129 USA; Harvard Med Sch, MA 02115 USA.
    Gyorgy, Bence
    Massachusetts Gen Hosp, MA 02129 USA; Harvard Med Sch, MA 02115 USA.
    Hallbeck, Martin
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Outeiro, Tiago F.
    Univ Med Ctr Gottingen, Germany; Max Planck Inst Expt Med, Germany; Newcastle Univ, England.
    Breakefield, Xandra O.
    Massachusetts Gen Hosp, MA 02129 USA; Harvard Med Sch, MA 02115 USA.
    Hyman, Bradley T.
    Massachusetts Gen Hosp, MA 02129 USA; Harvard Med Sch, MA 02115 USA.
    Ingelsson, Martin
    Uppsala Univ, Sweden; Massachusetts Gen Hosp, MA 02129 USA; Massachusetts Gen Hosp, MA 02129 USA; Harvard Med Sch, MA 02115 USA.
    Secretion and Uptake of -Synuclein Via Extracellular Vesicles in Cultured Cells2018In: Cellular and molecular neurobiology, ISSN 0272-4340, E-ISSN 1573-6830, Vol. 38, no 8, p. 1539-1550Article in journal (Refereed)
    Abstract [en]

    In Parkinsons disease and other Lewy body disorders, the propagation of pathology has been accredited to the spreading of extracellular -synuclein (-syn). Although the pathogenic mechanisms are not fully understood, cell-to-cell transfer of -syn via exosomes and other extracellular vesicles (EVs) has been reported. Here, we investigated whether altered molecular properties of -syn can influence the distribution and secretion of -syn in human neuroblastoma cells. Different -syn variants, including -syn:hemi-Venus and disease-causing mutants, were overexpressed and EVs were isolated from the conditioned medium. Of the secreted -syn, 0.1-2% was associated with vesicles. The major part of EV -syn was attached to the outer membrane of vesicles, whereas a smaller fraction was found in their lumen. For -syn expressed with N-terminal hemi-Venus, the relative levels associated with EVs were higher than for WT -syn. Moreover, such EV-associated -syn:hemi-Venus species were internalized in recipient cells to a higher degree than the corresponding free-floating forms. Among the disease-causing mutants, A53T -syn displayed an increased association with EVs. Taken together, our data suggest that -syn species with presumably lost physiological functions or altered aggregation properties may shift the cellular processing towards vesicular secretion. Our findings thus lend further support to the tenet that EVs can mediate spreading of harmful -syn species and thereby contribute to the pathology in -synucleinopathies.

  • 16.
    Haj Hosseini, Neda
    et al.
    Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation. Linköping University, The Institute of Technology.
    Richter, Johan
    Östergötlands Läns Landsting, Reconstruction Centre, Department of Neurosurgery UHL. Linköping University, Department of Biomedical Engineering. Linköping University, Faculty of Medicine and Health Sciences.
    Milos, Peter
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Neurosurgery. Neurokirurgi.
    Hallbeck, Martin
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Wårdell, Karin
    Linköping University, Department of Biomedical Engineering, Division of Biomedical Engineering. Linköping University, Faculty of Medicine and Health Sciences. Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation.
    Optical Guidance for Brain Tumor Stereotactic Biopsy2017Conference paper (Refereed)
  • 17.
    Haj-Hosseini, Neda
    et al.
    Linköping University, Department of Biomedical Engineering, Division of Biomedical Engineering. Linköping University, Faculty of Science & Engineering.
    Gimm, Oliver
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Linköping.
    Höög, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Johansson, Kenth
    Landstinget i Kalmar län och Sahlgrenska universitetssjukhus, Västra Götalandsregion.
    Optiska metoder för identifiering av bisköldkörtel och sköldkörtel2017Conference paper (Refereed)
    Abstract [sv]

    Identifiering av bisköldkörtlar är viktigt vid sköldkörtel- och bisköldkörtelkirurgi och kan vara svårt då de liknar omgivande vävnad såsom fett och lymfkörtlar. Peroperativ detektering av dessa vävnader kan förbättra möjligheten att bota patienter med hyperparathyroidism och minska risken för bisköldkörtelskador vid thyroideakirurgi. Optiska metoder är potentiella tekniker för att möjliggöra detta. Optiska tekniker utvärderades på vävnadsprover från patienter vid bisköldkörtel- och sköldkörteloperation. Teknikerna bestod av nära infraröd fluorescens (NIR) spektroskopi och optisk koherenstomografi (OCT) som ger en bild av vävnadens mikrostruktur liknande till ultraljud med högre upplösning (10 μm).

  • 18.
    Haj-Hosseini, Neda
    et al.
    Linköping University, Department of Biomedical Engineering, Division of Biomedical Engineering. Linköping University, Faculty of Science & Engineering.
    Richter, Johan
    Linköping University, Department of Biomedical Engineering. Linköping University, Faculty of Science & Engineering. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Neurosurgery.
    Milos, Peter
    Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Neurosurgery. Neurokirurgi.
    Hallbeck, Martin
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Clinical pathology.
    Wårdell, Karin
    Linköping University, Department of Biomedical Engineering, Division of Biomedical Engineering. Linköping University, Faculty of Science & Engineering.
    5-ALA fluorescence and laser Doppler flowmetry for guidance in a stereotactic brain tumor biopsy2018In: Biomedical Optics Express, E-ISSN 2156-7085, Vol. 9, no 5, p. 2284-2296Article in journal (Refereed)
    Abstract [en]

    A fiber optic probe was developed for guidance during stereotactic brain biopsy procedures to target tumor tissue and reduce the risk of hemorrhage. The probe was connected to a setup for the measurement of 5-aminolevulinic acid (5-ALA) induced fluorescence and microvascular blood flow. Along three stereotactic trajectories, fluorescence (n = 109) and laser Doppler flowmetry (LDF) (n = 144) measurements were done in millimeter increments. The recorded signals were compared to histopathology and radiology images. The median ratio of protoporphyrin IX (PpIX) fluorescence and autofluorescence (AF) in the tumor was considerably higher than the marginal zone (17.3 vs 0.9). The blood flow showed two high spots (3%) in total. The proposed setup allows simultaneous and real-time detection of tumor tissue and microvascular blood flow for tracking the vessels.

  • 19.
    Höög, Anders
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Karolinska Univ Hosp, Sweden; Karolinska Inst, Sweden.
    Kjellman, Magnus
    Karolinska Univ Hosp, Sweden; Karolinska Inst, Sweden.
    Mattsson, Per
    Karolinska Univ Hosp, Sweden; Karolinska Inst, Sweden.
    Juhlin, C. Christofer
    Karolinska Univ Hosp, Sweden; Karolinska Inst, Sweden.
    Shabo, Ivan
    Karolinska Univ Hosp, Sweden; Karolinska Inst, Sweden.
    Somatostatin Receptor Expression in Renal Cell Carcinoma-A New Front in the Diagnostics and Treatment of Renal Cell Carcinoma2018In: Clinical Genitourinary Cancer, ISSN 1558-7673, E-ISSN 1938-0682, Vol. 16, no 3, p. E517-E520Article in journal (Refereed)
    Abstract [en]

    Clinical Practice Points

    Renal cell carcinoma (RCC) has a poor prognosis and is difficult to treat because of its ability to spread asymptomatically and its resistance to chemotherapy.

    In this patient series, we report that RCC metastases can be identified using gallium-68 (68Ga)-edotreotide (DOTATOC) positron emission tomography/computed tomography (PET/CT).

    Immunostaining of tumor tissue from primary RCC tumors and their matched adrenal, pancreatic, and thyroid metastases showed that RCC cells express membranous somatostatin receptor 2.

    These findings indicate that 68Ga-DOTATOC PET/CT can be used as a new imaging modality in management of metastatic RCC and might contribute to the development of new somatostatin analogue-based methods for the treatment of metastatic RCC.

  • 20.
    Isaksson, Sofi
    et al.
    Lund University, Sweden.
    Jonsson, Per
    Lund University, Sweden.
    Monsef, Nastaran
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Clinical pathology.
    Brunnstrom, Hans
    Lund University, Sweden.
    Bendahl, Par-Ola
    Lund University, Sweden.
    Jonsson, Mats
    Lund University, Sweden.
    Staaf, Johan
    Lund University, Sweden.
    Planck, Maria
    Lund University, Sweden.
    CA 19-9 and CA 125 as potential predictors of disease recurrence in resectable lung adenocarcinoma2017In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, no 10, article id e186284Article in journal (Refereed)
    Abstract [en]

    Objectives Among patients who underwent primary surgery for non-small cell lung cancer (NSCLC), recurrent disease is frequent and cannot be accurately predicted solely from TNM stage and histopathological features. The aim of this study was to examine the association of tumor markers in pre-operative serum with recurrent disease. Material and methods Blood samples were collected prior to lung cancer surgery from 107 patients with stage I-III lung adenocarcinoma surgically treated at Lund University hospital, Lund, Sweden, between 2005 and 2011. The serum tumor markers Carcinoembryonic antigen (CEA), Neuron-specific enolase (NSE), Cancer antigen 125 (CA 125), Human epididymis protein 4 (HE4) and Carbohydrate antigen (CA 19-9) were analyzed retrospectively and clinical follow-up data were collected from patient charts. Forty (37%) patients were diagnosed with recurrent disease. Results Sixty-eight (64%) patients had at least one elevated tumor marker prior to surgery. In analysis of disease-free survival (DFS), CA 125 and/or CA 19-9 were significantly associated with recurrent disease adjusted to stage and adjuvant treatment (hazard ratio 2.8, 95% confidence interval 1.4-5.7, p = 0.006). Conclusion High pre-operative serum CA 19-9 and/or CA 125 might indicate an increased incidence of recurrent disease in resectable lung adenocarcinomas.

  • 21.
    Jedlinski, Adam
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Otorhinolaryngology in Linköping.
    Garvin, Stina
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Clinical pathology.
    Johansson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Edqvist, Per-Henrik
    Uppsala University, Uppsala, Sweden.
    Pontén, Fredrik
    Uppsala University, Uppsala, Sweden.
    Roberg, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Otorhinolaryngology in Linköping.
    Cetuximab sensitivity of head and neck squamous cell carcinoma xenografts is associated with treatment-induced reduction of EGFR, pEGFR, and pSrc2017In: Journal of Oral Pathology & Medicine, ISSN 0904-2512, E-ISSN 1600-0714, no 9, p. 717-724Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: The aim of this study was to validate in vitro drug sensitivity testing of head and neck squamous cell carcinoma (HNSCC)cell lines in an in vivo xenograft model, and to identify treatment-induced changes in the EGFR signaling pathway that could be used as markersfor cetuximab treatment response.

    METHODS: The in vitro cetuximab sensitivity of two HNSCC cell lines, UT-SCC-14 and UTSCC-45, was assessed using a crystal violet assay. In order to determine the corresponding in vivo sensitivity, UT-SCC-14 and UT-SCC-45 xenografts were generated in female BALB/c (nu/nu) nude mice. Mice were given three injections of intraperitoneal cetuximab or PBS and the tumor volume was recorded continuously. The expression of epidermal growth factor receptor (EGFR), phosphorylated EGFR (pEGFR), phosphorylated Src (pSrc), and Ki67 was investigated by immunohistochemistry.

    RESULTS: The treatment sensitive UT-SCC-14 cells were found to have an intrinsic cetuximab sensitivity (ICmabS) of 0.15 whereas the ICmabS of the insensitive cell line UT-SCC-45 was 0.78. The corresponding size ratio between untreated and cetuximab treated xenografts was 0.22 and 0.83 for UT-SCC-14 and UT-SCC-45, respectively. UT-SCC-14 cells had a higher baseline expression of pEGFR as compared to UT-SCC-45. Furthermore, in UT-SCC-14 xenografts there was a decrease in EGFR, pEGFR and pSrc upon cetuximab treatment. In contrast, a slight cetuximab-induced increase in EGFR, pEGFR and pSrc was observed in treatment-resistant UT-SCC-45 xenografts.

    CONCLUSIONS: The in vitro treatment sensitivity was reproduced in the in vivo model and cetuximab sensitivity was found to associate with a treatment-induced reduction in pEGFR and pSrc.

  • 22.
    Karlsson, Cecilia
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Insulin Signalling in Human Adipocytes and its Interplay with beta-Adrenergic Control of Lipolysis2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [sv]

    The prevalence of obesity has over the last 40 years nearly tripled and obesity is one of the major risk factors of developing type 2 diabetes. Type 2 diabetes was formerly called adultonset diabetes but today, probably due to the rise in childhood obesity, it is also seen in children and adolescents. Type 2 diabetes is diagnosed when the body no longer can control the glucose levels in the blood. This is due to an insulin resistant state in the insulin responding tissues, liver, adipose and muscle and insufficient production of insulin in the pancreas. However, in spite of extensive research the mechanisms behind insulin resistance is still not known.

    The adipose tissue is believed to play a major role in the development of whole body insulin resistance. Adipocytes are the most important sites for storage of the high energy containing triacylglycerols. Insulin stimulation causes the adipocyte to increase the uptake of glucose and to reduce lipolysis: the hydrolysis of triacylglycerol and release of glycerol and fatty acids. The insulin signalling network is complex with numerous proteins involved. These signaling proteins not only transmit the insulin signal but also create negative and positive feedbackloops and induce cross talk between different parts of the network and with the signalling of other hormones. One important positive feedback in insulin signalling is the mTORC1 mediated feedback to phosphorylation of IRS1 at serine 307. In paper I we found that in human adipocytes this feedback is not likely catalysed by the assumed kinase S6K1. However we find an immunoprecipitate of mTOR to contain a ser307 phosphorylating kinase.

    Scaffolding proteins serve as docking sites for several proteins to promote protein-protein interactions that facilitate signal transduction. In paper II we demonstrate the existence of the scaffolding protein IQGAP1 in human adipocytes and that the expression of IQGAP1 is downregulated in type 2 diabetes. We reveal that IQGAP1 co-localises with caveolae, invaginations of the plasma membrane where the insulin receptor is situated, and that this interaction is increased upon insulin stimulation.

    In paper III we focus on the control of lipolysis, and sought to understand the interplay between insulin and beta-adrenergic stimulation. We demonstrated that the re-esterification of fatty acids is downregulated in type 2 diabetes causing an increased release of fatty acids from the cells. We showed that beta-adrenergic stimulation with isoproterenol induced a negative feedback via PKA/Epac1 -> PI3K -> PKB -> PDE3B that reduced the cAMP levels and thereby also reduced lipolysis. We also showed that insulin, in addition to its well-known anti-lipolytic effect, at high concentrations had a positive effect on lipolysis. In conclusion we reveal an intricate control of the stimulation as well as the inhibition of lipolysis induced by both isoproterenol and insulin.

    List of papers
    1. Phosphorylation of IRS1 at Serine 307 in Response to Insulin in Human Adipocytes Is Not Likely to be Catalyzed by p70 Ribosomal S6 Kinase
    Open this publication in new window or tab >>Phosphorylation of IRS1 at Serine 307 in Response to Insulin in Human Adipocytes Is Not Likely to be Catalyzed by p70 Ribosomal S6 Kinase
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    2013 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 4Article in journal (Refereed) Published
    Abstract [en]

    The insulin receptor substrate-1 (IRS1) is phosphorylated on serine 307 (human sequence, corresponding to murine serine 302) in response to insulin as part of a feedback loop that controls IRS1 phosphorylation on tyrosine residues by the insulin receptor. This in turn directly affects downstream signaling and is in human adipocytes implicated in the pathogenesis of insulin resistance and type 2 diabetes. The phosphorylation is inhibited by rapamycin, a specific inhibitor of mammalian target of rapamycin (mTOR) in complex with raptor (mTORC1). The mTORC1-downstream p70 ribosomal protein S6 kinase (S6K1), which is activated by insulin, can phosphorylate IRS1 at serine 307 in vitro and is considered the physiological protein kinase. Because the IRS1 serine 307-kinase catalyzes a critical step in the control of insulin signaling and constitutes a potential target for treatment of insulin resistance, it is important to know whether S6K1 is the physiological serine 307-kinase or not. We report that, by several criteria, S6K1 does not phosphorylate IRS1 at serine 307 in response to insulin in intact human primary adipocytes: (i) The time-courses for phosphorylation of S6K1 and its phosphorylation of S6 are not compatible with the phosphorylation of IRS1 at serine 307; (ii) A dominant-negative construct of S6K1 inhibits the phosphorylation of S6, without effect on the phosphorylation of IRS1 at serine 307; (iii) The specific inhibitor of S6K1 PF-4708671 inhibits the phosphorylation of S6, without effect on phosphorylation of IRS1 at serine 307. mTOR-immunoprecipitates from insulin-stimulated adipocytes contains an unidentified protein kinase specific for phosphorylation of IRS1 at serine 307, but it is not mTOR or S6K1.

    Place, publisher, year, edition, pages
    Public Library of Science, 2013
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-93257 (URN)10.1371/journal.pone.0059725 (DOI)000317717300032 ()
    Note

    Funding Agencies|Swedish Diabetes Fund||Novo Nordic Foundation||University of Linkoping||Swedish Research Council||

    Available from: 2013-05-28 Created: 2013-05-28 Last updated: 2018-04-27
    2. Scaffolding protein IQGAP1: an insulin-dependent link between caveolae and the cytoskeleton in primary human adipocytes?
    Open this publication in new window or tab >>Scaffolding protein IQGAP1: an insulin-dependent link between caveolae and the cytoskeleton in primary human adipocytes?
    Show others...
    2016 (English)In: Biochemical Journal, ISSN 0264-6021, E-ISSN 1470-8728, Vol. 473, no 19, p. 3177-3188Article in journal (Refereed) Published
    Abstract [en]

    The ubiquitously expressed IQ motif-containing GTPase activating protein-1 (IQGAP1) is a scaffolding protein implicated in an array of cellular functions, in particular by binding to cytoskeletal elements and signaling proteins. A role of IQGAP1 in adipocytes has not been reported. We therefore investigated the cellular IQGAP1 interactome in primary human adipocytes. Immunoprecipitation and quantitative mass spectrometry identified caveolae and caveolae-associated proteins as the major IQGAP1 interactors alongside cytoskeletal proteins. We confirmed co-localization of IQGAP1 with the defining caveolar marker protein caveolin-1 by confocal microscopy and proximity ligation assay. Most interestingly, insulin enhanced the number of IQGAP1 interactions with caveolin-1 by five-fold. Moreover, we found a significantly reduced abundance of IQGAP1 in adipocytes from patients with type 2 diabetes compared with cells from nondiabetic control subjects. Both the abundance of IQGAP1 protein and mRNA were reduced, indicating a transcriptional defect in diabetes. Our findings suggest a novel role of IQGAP1 in insulin-regulated interaction between caveolae and cytoskeletal elements of the adipocyte, and that this is quelled in the diabetic state.

    Place, publisher, year, edition, pages
    Portland Press, 2016
    National Category
    Cell Biology
    Identifiers
    urn:nbn:se:liu:diva-131958 (URN)10.1042/BCJ20160581 (DOI)000393755500017 ()27458251 (PubMedID)
    Note

    Funding agencies: University of Linkoping; 3-year program at the Swedish Diabetes Fund; 5-year program at the Swedish Research Council

    Available from: 2016-10-12 Created: 2016-10-12 Last updated: 2018-04-27Bibliographically approved
  • 23.
    Klawonn, Anna
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Fritz, Michael
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Nilsson, Anna
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Bonaventura, Jordi
    NIDA, MD USA.
    Shionoya, Kiseko
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Mirrasekhian, Elahe
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Karlsson, Urban
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Jaarola, Maarit
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Granseth, Björn
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Blomqvist, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Michaelides, Michael
    NIDA, MD USA; Johns Hopkins Sch Med, MD USA.
    Engblom, David
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Motivational valence is determined by striatal melanocortin 4 receptors2018In: Journal of Clinical Investigation, ISSN 0021-9738, E-ISSN 1558-8238, Vol. 128, no 7, p. 3160-3170Article in journal (Refereed)
    Abstract [en]

    It is critical for survival to assign positive or negative valence to salient stimuli in a correct manner. Accordingly, harmful stimuli and internal states characterized by perturbed homeostasis are accompanied by discomfort, unease, and aversion. Aversive signaling causes extensive suffering during chronic diseases, including inflammatory conditions, cancer, and depression. Here, we investigated the role of melanocortin 4 receptors (MC4Rs) in aversive processing using genetically modified mice and a behavioral test in which mice avoid an environment that they have learned to associate with aversive stimuli. In normal mice, robust aversions were induced by systemic inflammation, nausea, pain, and. opioid receptorinduced dysphoria. In sharp contrast, mice lacking MC4Rs displayed preference or indifference toward the aversive stimuli. The unusual flip from aversion to reward in mice lacking MC4Rs was dopamine dependent and associated with a change from decreased to increased activity of the dopamine system. The responses to aversive stimuli were normalized when MC4Rs were reexpressed on dopamine D1 receptor-expressing cells or in the striatum of mice otherwise lacking MC4Rs. Furthermore, activation of arcuate nucleus proopiomelanocortin neurons projecting to the ventral striatum increased the activity of striatal neurons in an MC4R-dependent manner and elicited aversion. Our findings demonstrate that melanocortin signaling through striatal MC4Rs is critical for assigning negative motivational valence to harmful stimuli.

  • 24.
    Klawonn, Anna
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Nilsson, Anna
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Rådberg, Carl F.
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Lindström, Sarah
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences.
    Ericson, Mia
    University of Gothenburg, Sweden.
    Granseth, Björn
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Engblom, David
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Fritz, Michael
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    The Sigma-2 Receptor Selective Agonist Siramesine (Lu 28-179) Decreases Cocaine-Reinforced Pavlovian Learning and Alters Glutamatergic and Dopaminergic Input to the Striatum2017In: Frontiers in Pharmacology, ISSN 1663-9812, E-ISSN 1663-9812, Vol. 8, article id 714Article in journal (Refereed)
    Abstract [en]

    Drug addiction is a chronic, debilitating disease that affects millions of people around the world causing a substantial societal burden. Despite decades of research efforts, treatment possibilities remain limited and relapse represents the most treatmentresistant element. Neurosteroid sigma-1 receptors have been meticulously studied in psychostimulant reinforced Pavlovian learning, while the sigma-2 receptor subtype has remained unexplored. Recent development of selective sigma-2 receptor ligands have now made it possible to investigate if the sigma-2 receptor system is a potential target to treat drug addiction. We examined the effect of the sigma-2 receptor agonist Siramesine (Lu 28-179) on cocaine-associated locomotion, Pavlovian learning, and reward neurocircuitry using electrophysiology recordings and in vivo microdialysis. We found that Siramesine significantly attenuated conditioned place preference acquisition and expression, as well as it completely blocked cocaine-primed reinstatement. Siramesine, in a similar manner as the selective sigma-1 receptor antagonist BD 1063, decreased acute locomotor responses to cocaine. Immunohistochemistry suggests co-expression of progesterone receptor membrane component 1/sigma-2 receptors and vesicular glutamate transporter 1 in presynaptic boutons of the nucleus accumbens (NAc). Whole-cell voltage clamp recordings of neurons in the NAc indicated that Siramesine decreases the presynaptic release probability of glutamate. Further, we demonstrated, via in vivo microdialysis, that Siramesine significantly decreased cocaine-evoked dopamine release in the striatum of freely moving mice. Collectively, these findings demonstrate that sigma-2 receptors regulate neurocircuitry responsible for positive reinforcement and thereby play a role in cocaine-reinforced Pavlovian behaviors.

  • 25.
    Larsson, Johan
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Larsson, H. Peter
    Univ Miami, FL USA.
    Liin, Sara
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    KCNE1 tunes the sensitivity a: K(v)7.1 to polyunsaturated fatty acids by moving turret residues close to the binding site2018In: eLIFE, E-ISSN 2050-084X, Vol. 7, article id e37257Article in journal (Refereed)
    Abstract [en]

    The voltage-gated potassium channel K(v)7.1 and the auxiliary subunit KCNE1 together form the cardiac I-Ks channel, which is a proposed target for future anti-arrhythmic drugs. We previously showed that polyunsaturated fatty acids (PUFAs) activate K(v)7.1 via an electrostatic mechanism. The activating effect was abolished when K(v)7.1 was co-expressed with KCNE1, as KCNE1 renders PUFAs ineffective by promoting PUFA protonation. PUFA protonation reduces the potential of PUFAs as anti-arrhythmic compounds. It is unknown how KCNE1 promotes PUFA protonation. Here, we found that neutralization of negatively charged residues in the S5-P-helix loop of K(v)7.1 restored PUFA effects on K(v)7.1 co-expressed with KCNE1 in Xenopus oocytes. We propose that KCNE1 moves the S5-P-helix loop of K(v)7.1 towards the PUFA-binding site, which indirectly causes PUFA protonation, thereby reducing the effect of PUFAs on K(v)7.1. This mechanistic understanding of how KCNE1 alters K(v)7.1 pharmacology is essential for development of drugs targeting the I-Ks channel.

  • 26.
    Larsson, Max
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Non-canonical heterogeneous cellular distribution and co-localization of CaMKIIα and CaMKIIβ in the spinal superficial dorsal horn.2018In: Brain Structure and Function, ISSN 1863-2653, E-ISSN 1863-2661, Vol. 223, no 3, p. 1437-1457Article in journal (Refereed)
    Abstract [en]

    Ca2+/calmodulin-dependent protein kinase II (CaMKII) is a key enzyme in long-term plasticity in many neurons, including in the nociceptive circuitry of the spinal dorsal horn. However, although the role of CaMKII heterooligomers in neuronal plasticity is isoform-dependent, the distribution and co-localization of CaMKII isoforms in the dorsal horn have not been comprehensively investigated. Here, quantitative immunofluorescence analysis was used to examine the distribution of the two major neuronal CaMKII isoforms, α and β, in laminae I–III of the rat dorsal horn, with reference to inhibitory interneurons and neuronal populations defined by expression of parvalbumin, calretinin, and calbindin D28k. Unexpectedly, all or nearly all inhibitory and excitatory neurons showed both CaMKIIα and CaMKIIβ immunoreactivity, although at highly variable levels. Lamina III neurons showed less CaMKIIα immunoreactivity than laminae I–II neurons. Whereas CaMKIIα immunoreactivity was found at nearly similar levels in inhibitory and excitatory neurons, CaMKIIβ generally showed considerably lower immunoreactivity in inhibitory neurons. Distinct populations of inhibitory calretinin neurons and excitatory parvalbumin neurons exhibited high CaMKIIα-to-CaMKIIβ immunoreactivity ratios. CaMKIIα and CaMKIIβ immunoreactivity showed positive correlation at GluA2+ puncta in pepsin-treated tissue. These results suggest that, unlike the forebrain, the dorsal horn is characterized by similar expression of CaMKIIα in excitatory and inhibitory neurons, whereas CaMKIIβ is less expressed in inhibitory neurons. Moreover, CaMKII isoform expression varies considerably within and between neuronal populations defined by laminar location, calcium-binding protein expression, and transmitter phenotype, suggesting differences in CaMKII function both between and within neuronal populations in the superficial dorsal horn.

  • 27.
    Liin, Sara
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Lund, Per-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Larsson, Johan
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Brask, Johan
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Wallner, Björn
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, Faculty of Science & Engineering.
    Elinder, Fredrik
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Biaryl sulfonamide motifs up- or down-regulate ion channel activity by activating voltage sensors2018In: The Journal of General Physiology, ISSN 0022-1295, E-ISSN 1540-7748, Vol. 150, no 8, p. 1215-1230Article in journal (Refereed)
    Abstract [en]

    Voltage-gated ion channels are key molecules for the generation of cellular electrical excitability. Many pharmaceutical drugs target these channels by blocking their ion-conducting pore, but in many cases, channel-opening compounds would be more beneficial. Here, to search for new channel-opening compounds, we screen 18,000 compounds with high-throughput patch-clamp technology and find several potassium-channel openers that share a distinct biaryl-sulfonamide motif. Our data suggest that the negatively charged variants of these compounds bind to the top of the voltage-sensor domain, between transmembrane segments 3 and 4, to open the channel. Although we show here that biaryl-sulfonamide compounds open a potassium channel, they have also been reported to block sodium and calcium channels. However, because they inactivate voltage-gated sodium channels by promoting activation of one voltage sensor, we suggest that, despite different effects on the channel gates, the biaryl-sulfonamide motif is a general ion-channel activator motif. Because these compounds block action potential-generating sodium and calcium channels and open an action potential-dampening potassium channel, they should have a high propensity to reduce excitability. This opens up the possibility to build new excitability-reducing pharmaceutical drugs from the biaryl-sulfonamide scaffold.

  • 28.
    Liin, Sara
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Yazdi, Samira
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Ramentol, Rosamary
    Univ Miami, FL 33136 USA.
    Barro-Soria, Rene
    Univ Miami, FL 33136 USA.
    Larsson, H. Peter
    Univ Miami, FL 33136 USA.
    Mechanisms Underlying the Dual Effect of Polyunsaturated Fatty Acid Analogs on Kv7.12018In: Cell reports, ISSN 2211-1247, E-ISSN 2211-1247, Vol. 24, no 11, p. 2908-2918Article in journal (Refereed)
    Abstract [en]

    Polyunsaturated fatty acid (PUFA) analogs represent a new class of potential anti-arrhythmic K(V)7.1 and K(V)7.1+KCNE1 channel activators. In this study, we describe dual independent activating effects of negatively charged PUFA analogs on K(V)7.1 and K(V)7.1+KCNE1 that are dependent on discrete channel motifs. PUFA analogs are critically dependent on K326 in S6 of K(V)7.1 to increase the maximum conductance and critically dependent on specific S4 arginines in K(V)7.1 to shift the voltage dependence of channel opening toward negative voltages. Our findings provide insights into how K(V)7.1+KCNE1 activators may interact electrostatically both with the pore domain and the voltage-sensing domain to augment channel activity. We believe that the molecular understanding of how PUFA analogs induce dual independent activating effects is an important step toward the development of effective anti-arrhythmic drugs that target K(V)7.1 channels.

  • 29.
    Lindström, Annelie
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Midtbö, Kristine Maria
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Arnesson, Lars-Gunnar
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Linköping.
    Garvin, Stina
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Clinical pathology.
    Shabo, Ivan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Linköping. Karolinska Institute, Sweden; Karolinska University Hospital, Sweden.
    Fusion between M2-macrophages and cancer cells results in a subpopulation of radioresistant cells with enhanced DNA-repair capacity2017In: OncoTarget, ISSN 1949-2553, E-ISSN 1949-2553, Vol. 8, no 31, p. 51370-51386Article in journal (Refereed)
    Abstract [en]

    Cell fusion is a natural biological process in normal development and tissue regeneration. Fusion between cancer cells and macrophages results in hybrids that acquire genetic and phenotypic characteristics from both maternal cells. There is a growing body of in vitro and in vivo data indicating that this process also occurs in solid tumors and may play a significant role in tumor progression. However, investigations of the response of macrophage: cancer cell hybrids to radiotherapy have been lacking. In this study, macrophage: MCF-7 hybrids were generated by spontaneous in vitro cell fusion. After irradiation, both hybrids and their maternal MCF-7 cells were treated with 0 Gy, 2.5 Gy and 5 Gy.-radiation and examined by clonogenic survival and comet assays at three time points (0 h, 24 h, and 48 h). Compared to maternal MCF-7 cells, the hybrids showed increased survival fraction and plating efficiency (colony formation ability) after radiation. The hybrids developed less DNA-damage, expressed significantly lower residual DNA-damage, and after higher radiation dose showed less heterogeneity in DNA-damage compared to their maternal MCF-7 cells. To our knowledge this is the first study that demonstrates that macrophage: cancer cell fusion generates a subpopulation of radioresistant cells with enhanced DNA-repair capacity. These findings provide new insight into how the cell fusion process may contribute to clonal expansion and tumor heterogeneity. Furthermore, our results provide support for cell fusion as a mechanism behind the development of radioresistance and tumor recurrence.

  • 30.
    Matsuwaki, Takashi
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. University of Tokyo, Japan.
    Shionoya, Kiseko
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Ihnatko, Robert
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Eskilsson, Anna
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Kakuta, Shigeru
    University of Tokyo, Japan.
    Dufour, Sylvie
    CNRS, France.
    Schwaninger, Markus
    University of Lubeck, Germany.
    Waisman, Ari
    Johannes Gutenberg University of Mainz, Germany.
    Mueller, Werner
    University of Manchester, England.
    Pinteaux, Emmanuel
    University of Manchester, England.
    Engblom, David
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Blomqvist, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Involvement of interleukin-1 type 1 receptors in lipopolysaccharide-induced sickness responses2017In: Brain, behavior, and immunity, ISSN 0889-1591, E-ISSN 1090-2139, Vol. 66, p. 165-176Article in journal (Refereed)
    Abstract [en]

    Sickness responses to lipopolysaccharide (LPS) were examined in mice with deletion of the interleukin (IL)-1 type 1 receptor (IL-1R1). IL-1R1 knockout (1(0) mice displayed intact anorexia and HPA-axis activation to intraperitoneally injected LPS (anorexia: 10 or 120 mu g/kg; HPA-axis: 120 mu g/kg), but showed attenuated but not extinguished fever (120 g/kg). Brain PGE2 synthesis was attenuated, but Cox-2 induction remained intact. Neither the tumor necrosis factor-alpha (TNF alpha) inhibitor etanercept nor the IL -6 receptor antibody tocilizumab abolished the LPS induced fever in IL -1R1 KO mice. Deletion of IL -1R1 specifically in brain endothelial cells attenuated the LPS induced fever, but only during the late, 3rd phase of fever, whereas deletion of IL-1R1 on neural cells or on peripheral nerves had little or no effect on the febrile response. We conclude that while IL-1 signaling is not critical for LPS induced anorexia or stress hormone release, IL-1R1, expressed on brain endothelial cells, contributes to the febrile response to LPS. However, also in the absence of IL-1R1, LPS evokes a febrile response, although this is attenuated. This remaining fever seems not to be mediated by IL-6 receptors or TNFa, but by some yet unidentified pyrogenic factor. 

  • 31.
    Mirrasekhian, Elahe
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Nilsson, Johan L. Å.
    Division of Clinical Chemistry and Pharmacology, Department of Laboratory Medicine, Lund University, Lund, Sweden.
    Shionoya, Kiseko
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Blomgren, Anders
    Division of Clinical Chemistry and Pharmacology, Department of Laboratory Medicine, Lund University, Lund, Sweden.
    Zygmunt, Peter M.
    Division of Clinical Chemistry and Pharmacology, Department of Laboratory Medicine, Lund University, S-221 85 Lund, Sweden.
    Engblom, David
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Högestätt, Edward D.
    Division of Clinical Chemistry and Pharmacology, Department of Laboratory Medicine, Lund University, Lund, Sweden.
    Blomqvist, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    The antipyretic effect of paracetamol occurs independent of transient receptor potential ankyrin 1–mediated hypothermia and is associated with prostaglandin inhibition in the brain2018In: The FASEB Journal, ISSN 0892-6638, E-ISSN 1530-6860Article in journal (Refereed)
    Abstract [en]

    The mode of action of paracetamol (acetaminophen), which is widely used for treating pain and fever, has remained obscure, but may involve several distinct mechanisms, including cyclooxygenase inhibition and transient receptor potential ankyrin 1 (TRPA1) channel activation, the latter being recently associated with paracetamol?s propensity to elicit hypothermia at higher doses. Here, we examined whether the antipyretic effect of paracetamol was due to TRPA1 activation or cyclooxygenase inhibition. Treatment of wild-type and TRPA1 knockout mice rendered febrile by immune challenge with LPS with a dose of paracetamol that did not produce hypothermia (150 mg/kg) but is known to be analgetic, abolished fever in both genotypes. Paracetamol completely suppressed the LPS-induced elevation of prostaglandin E2 in the brain and also reduced the levels of several other prostanoids. The hypothermia induced by paracetamol was abolished in mice treated with the electrophile-scavenger N-acetyl cysteine. We conclude that paracetamol?s antipyretic effect in mice is dependent on inhibition of cyclooxygenase activity, including the formation of pyrogenic prostaglandin E2, whereas paracetamol-induced hypothermia likely is mediated by the activation of TRPA1 by electrophilic metabolites of paracetamol, similar to its analgesic effect in some experimental paradigms.?Mirrasekhian, E., Nilsson, J. L. Å., Shionoya, K., Blomgren, A., Zygmunt, P. M., Engblom, D., Högestätt, E. D., Blomqvist, A. The antipyretic effect of paracetamol occurs independent of transient receptor potential ankyrin 1?mediated hypothermia and is associated with prostaglandin inhibition in the brain.

  • 32.
    Molinas, Andrea
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Turkina, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Magnusson, Karl-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Mirazimi, Ali
    Department of Laboratory Medicine, Karolinska Institute, Stockholm, Sweden.
    Vikström, Elena
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Perturbation of Wound Healing, Cytoskeletal Organization and Cellular Protein Networks during Hazara Virus Infection2017In: Frontiers in cell and developmental biology, ISSN 2296-634X, Vol. 5, article id 98Article in journal (Refereed)
    Abstract [en]

    Normal epithelial and endothelial renewal and healing after bacterial and viral challenges are essential for homeostasis along the intestine and the blood and lymphatic vessels. We thus investigated whether and how virus affects migration of human epithelial cells and specifically how the nucleocapsid protein (N) modulates the cellular proteome and interactome using human Caco-2 cells in a wound-healing assay with Hazara virus as a model. Here, Hazara virus blocked cell migration in a dose- and time-dependent manner, disrupted the actin cytoskeleton and specifically reduced the expression of the IQ-motif-containing GTPase-activating protein 1 (IQGAP1) and water channel aquaporin 6 (AQP6) that regulate cytoskeletal organization, water homeostasis and vesicle communication. Moreover, in the Caco-2 cell proteome, we identified several distinct groups of molecules associating with N upon Hazara virus infection, being involved in the ensemble of important cellular processes, e.g., chaperone activity, metabolism, cellular defense against infections, cell morphology, and migration. These events do not only facilitate the virus life cycle, but they are also crucial for membrane and cytoskeleton dynamics, cellular self-renewal and wound healing, being so essential for body integrity and homeostasis.

  • 33.
    Nasr, Patrik
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Gastroentorology.
    Forsgren, Mikael F.
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Radiation Physics. Linköping University, Center for Medical Image Science and Visualization (CMIV). Wolfram MathCore AB, Linköping, Sweden.
    Ignatova, Simone
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Clinical pathology.
    Dahlström, Nils
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Radiology in Linköping. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Cedersund, Gunnar
    Linköping University, Department of Biomedical Engineering, Division of Biomedical Engineering. Linköping University, Faculty of Science & Engineering. Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Dahlqvist Leinhard, Olof
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Radiation Physics. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Norén, Bengt
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Region Östergötland, Center for Diagnostics, Department of Radiology in Linköping. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Faculty of Medicine and Health Sciences.
    Ekstedt, Mattias
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Gastroentorology.
    Lundberg, Peter
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Radiation Physics. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Kechagias, Stergios
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Gastroentorology.
    Using a 3% Proton Density Fat Fraction as a Cut-off Value Increases Sensitivity of Detection of Hepatic Steatosis, Based on Results from Histopathology Analysis2017In: Gastroenterology, ISSN 0016-5085, E-ISSN 1528-0012, Vol. 153, no 1, p. 53-+Article in journal (Refereed)
    Abstract [en]

    It is possible to estimate hepatic triglyceride content by calculating the proton density fat fraction (PDFF), using proton magnetic resonance spectroscopy (less thansuperscriptgreater than1less than/superscriptgreater thanH-MRS), instead of collecting and analyzing liver biopsies to detect steatosis. However, the current PDFF cut-off value (5%) used to define steatosis by magnetic resonance was derived from studies that did not use histopathology as the reference standard. We performed a prospective study to determine the accuracy of less thansuperscriptgreater than1less than/superscriptgreater thanH-MRS PDFF in measurement of steatosis using histopathology analysis as the standard. We collected clinical, serologic, less thansuperscriptgreater than1less than/superscriptgreater thanH-MRS PDFF, and liver biopsy data from 94 adult patients with increased levels of liver enzymes (6 months or more) referred to the Department of Gastroenterology and Hepatology at Linköping University Hospital in Sweden from 2007 through 2014. Steatosis was graded using the conventional histopathology method and fat content was quantified in biopsy samples using stereological point counts (SPCs). We correlated less thansuperscriptgreater than1less than/superscriptgreater thanH-MRS PDFF findings with SPCs (r = 0.92; P less than.001). less thansuperscriptgreater than1less than/superscriptgreater thanH-MRS PDFF results correlated with histopathology results (ρ = 0.87; P less than.001), and SPCs correlated with histopathology results (ρ = 0.88; P less than.001). All 25 subjects with PDFF values of 5.0% or more had steatosis based on histopathology findings (100% specificity for PDFF). However, of 69 subjects with PDFF values below 5.0% (negative result), 22 were determined to have steatosis based on histopathology findings (53% sensitivity for PDFF). Reducing the PDFF cut-off value to 3.0% identified patients with steatosis with 100% specificity and 79% sensitivity; a PDFF cut-off value of 2.0% identified patients with steatosis with 94% specificity and 87% sensitivity. These findings might be used to improve non-invasive detection of steatosis.

  • 34.
    Nasr, Patrik
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Gastroentorology.
    Ignatova, Simone
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Kechagias, Stergios
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Gastroentorology.
    Ekstedt, Mattias
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Gastroentorology.
    Natural history of nonalcoholic fatty liver disease: A prospective follow-up study with serial biopsies.2018In: Hepatology communications, ISSN 2471-254X, Vol. 2, no 2, p. 199-210Article in journal (Refereed)
    Abstract [en]

    Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease in the world. The complete natural history of NAFLD is unknown because few high-quality follow-up studies have been conducted. Our aim was to find variables predicting disease severity through an extended follow-up with serial biopsies. In a prospective cohort study, 129 patients who enrolled between 1988 and 1993 were asked to participate in a follow-up study on two occasions; biochemical, clinical, and histologic data were documented. The mean time between biopsies was 13.7 (±1.7) and 9.3 (±1.0) years, respectively. At the end of the study period, 12 patients (9.3%) had developed end-stage liver disease and 34% had advanced fibrosis. Out of the 113 patients with baseline low fibrosis (<3), 16% developed advanced fibrosis. Fibrosis progression did not differ among the different stages of baseline fibrosis (P = 0.374). Fifty-six patients (43%) had isolated steatosis, of whom 9% developed advanced fibrosis (3 patients with biopsy-proven fibrosis stage F3-F4 and 2 patients with end-stage liver disease). Fibrosis stage, ballooning, and diabetes were more common in patients who developed end-stage liver disease; however, there were no baseline clinical, histologic, or biochemical variables that predicted clinical significant disease progression. Conclusion: NAFLD is a highly heterogeneous disease, and it is surprisingly hard to predict fibrosis progression. Given enough time, NAFLD seems to have a more dismal prognosis then previously reported, with 16% of patients with fibrosis stage <3 developing advanced fibrosis and 9.3% showing signs of end-stage liver disease. (Hepatology Communications 2018;2:199-210).

  • 35.
    Nilsson, Anna
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Elander, Louise
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences.
    Hallbeck, Martin
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Clinical pathology.
    Örtegren (Kugelberg), Unn
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Engblom, David
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Blomqvist, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    The involvement of prostaglandin E2 in interleukin-1β evoked anorexia is strain dependent2017In: Brain, behavior, and immunity, ISSN 0889-1591, E-ISSN 1090-2139, Vol. 60, p. 27-31Article in journal (Refereed)
    Abstract [en]

    From experiments in mice in which the prostaglandin E2 (PGE2) synthesizing enzyme mPGES-1 was genetically deleted, as well as from experiments in which PGE2 was injected directly into the brain, PGE2 has been implicated as a mediator of inflammatory induced anorexia. Here we aimed at examining which PGE2 receptor (EP1–4) that was critical for the anorexic response to peripherally injected interleukin-1β (IL-1β). However, deletion of neither EP receptor in mice, either globally (for EP1, EP2, and EP3) or selectively in the nervous system (EP4), had any effect on the IL-1β induced anorexia. Because these mice were all on a C57BL/6 background, whereas previous observations demonstrating a role for induced PGE2 in IL-1β evoked anorexia had been carried out on mice on a DBA/1 background, we examined the anorexic response to IL-1β in mice with deletion of mPGES-1 on a C57BL/6 background and a DBA/1 background, respectively. We confirmed previous findings that mPGES-1 knock-out mice on a DBA/1 background displayed attenuated anorexia to IL-1β; however, mice on a C57BL/6 background showed the same profound anorexia as wild type mice when carrying deletion of mPGES-1, while displaying almost normal food intake after pretreatment with a cyclooxygenase-2 inhibitor. We conclude that the involvement of induced PGE2 in IL-1β evoked anorexia is strain dependent and we suggest that different routes that probably involve distinct prostanoids exist by which inflammatory stimuli may evoke an anorexic response and that these routes may be of different importance in different strains of mice.

  • 36.
    Nilsson, Anna
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Wilhelms, Daniel
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences. Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Region Östergötland, Local Health Care Services in Central Östergötland, Department of Emergency Medicine.
    Mirrasekhian, Elahe
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Jaarola, Maarit
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Blomqvist, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Engblom, David
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Inflammation-induced anorexia and fever are elicited by distinct prostaglandin dependent mechanisms, whereas conditioned taste aversion is prostaglandin independent.2017In: Brain, behavior, and immunity, ISSN 0889-1591, E-ISSN 1090-2139, Vol. 61, p. 236-243, article id S0889-1591(16)30549-9Article in journal (Refereed)
    Abstract [en]

    Systemic inflammation evokes an array of brain-mediated responses including fever, anorexia and taste aversion. Both fever and anorexia are prostaglandin dependent but it has been unclear if the cell-type that synthesizes the critical prostaglandins is the same. Here we show that pharmacological inhibition or genetic deletion of cyclooxygenase (COX)-2, but not of COX-1, attenuates inflammation-induced anorexia. Mice with deletions of COX-2 selectively in brain endothelial cells displayed attenuated fever, as demonstrated previously, but intact anorexia in response to peripherally injected lipopolysaccharide (10μg/kg). Whereas intracerebroventricular injection of a cyclooxygenase inhibitor markedly reduced anorexia, deletion of COX-2 selectively in neural cells, in myeloid cells or in both brain endothelial and neural cells had no effect on LPS-induced anorexia. In addition, COX-2 in myeloid and neural cells was dispensable for the fever response. Inflammation-induced conditioned taste aversion did not involve prostaglandin signaling at all. These findings collectively show that anorexia, fever and taste aversion are triggered by distinct routes of immune-to-brain signaling.

  • 37.
    Nord, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Local Health Care Services in Central Östergötland, Department of Neurology.
    Levodopa pharmacokinetics -from stomach to brain: A study on patients with Parkinson’s disease2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Parkinson’s disease (PD) is one of the most common neurodegenerative disorders and it is caused by a loss of dopamine (DA) producing neurons in the basal ganglia in the brain. The PD patient suffers from motor symptoms such as tremor, bradykinesia and rigidity and treatment with levodopa (LD), the precursor of DA, has positive effects on these symptoms. Several factors affect the availability of orally given LD. Gastric emptying (GE) is one factor and it has been shown to be delayed in PD patients resulting in impaired levodopa uptake. Different enzymes metabolize LD on its way from the gut to the brain resulting in less LD available in the brain and more side effects from the metabolites. By adding dopa decarboxylase inhibitors (carbidopa or benserazide) or COMT-inhibitors (e.g. entacapone) the bioavailability of LD increases significantly and more LD can pass the blood-brain-barrier and be converted to DA in the brain. It has been considered of importance to avoid high levodopa peaks in the brain because this seems to induce changes in postsynaptic dopaminergic neurons causing disabling motor complications in PD patients. More continuously given LD, e.g. duodenal or intravenous (IV) infusions, has been shown to improve these motor complications. Deep brain stimulation of the subthalamic nucleus (STN DBS) has also been proven to improve motor complications and to make it possible to reduce the LD dosage in PD patients.

    In this doctoral thesis the main purpose is to study the pharmacokinetics of LD in patients with PD and motor complications; in blood and subcutaneous tissue and study the effect of GE and PD stage on LD uptake and the effect of continuously given LD (CDS) on LD uptake and GE; in blood and cerebrospinal fluid (CSF) when adding the peripheral enzyme inhibitors entacapone and carbidopa to LD infusion IV; in brain during STN DBSand during oral or IV LD treatment.

    To conclude, LD uptake is more favorable in PD patients with less severe disease and GE is delayed in PD patients. No obvious relation between LD uptake and GE or between GE and PD stage is seen and CDS decreases the LD levels. Entacapone increases the maximal concentration of LD in blood and CSF. This is more evident with additional carbidopa and important to consider in avoiding high LD peaks in brain during PD treatment. LD in brain increases during both oral and IV LD treatment and the DA levels follows LD well indicating that PD patients still have capacity to metabolize LD to DA despite probable pronounced nigral degeneration. STN DBS seems to increase putaminal DA levels and together with IV LD treatment also increases LD in brain possibly explaining why it is possible to decrease LD medication after STN DBS surgery.

    List of papers
    1. Is Levodopa Pharmacokinetics in Patients with Parkinson’s Disease Depending on Gastric Emptying?
    Open this publication in new window or tab >>Is Levodopa Pharmacokinetics in Patients with Parkinson’s Disease Depending on Gastric Emptying?
    2017 (English)In: Advances in Parkinsons Disease, ISSN 2169-9712, Vol. 06, no 01Article in journal (Refereed) Published
    Abstract [en]

    Levodopa uptake from the gastrointestinal tract in patients with Parkinson’s disease (PD) can be affected by delayed gastric emptying (GE). This might lead to fluctuating levodopa levels resulting in increased motor fluctuations. Continuous dopaminergic stimulation (CDS) improves motor fluctuations and could be a result of smoothening in levodopa uptake. In this study we wanted to study the levodopa pharmacokinetics peripherally in PD patients with motor fluctuations and investigate the relation between levodopa uptake and GE and the effect of CDS. PD patients with wearing off (group 1) and on-off syndrome (group 2) were included. Breath tests were performed to evaluate the half time (T1/2) of GE. Concomitantly 1 tablet of Madopark® was given and the levodopa concentrations in blood and subcutaneous (SC) tissue were analyzed for both groups. Group 2 was then given a 10-d continuous intravenous levodopa treatment and the tests were repeated. Higher levels of levodopa in group 1 compared to group 2 in blood (p = 0.014) were seen. The GE was delayed in both group 1 (p < 0.001) and group 2 (p < 0.05) compared to a reference group with healthy volunteers with T1/2 median values 105 and 78 min vs. 72 min. There was no difference in GE between the two PD groups (p = 0.220) or in group 2 before and after infusion period (p = 0.861). CDS resulted in lower levodopa levels in blood (p < 0.001) and SC tissue (p < 0.01). In conclusion, PD patients in early complication phase have a more favourable levodopa uptake than patients later in disease. We found delayed GE in PD patients with motor fluctuations but no obvious relation between GE and levodopa uptake or GE and PD stage. The effect of CDS indicates no effect of CDS on the mechanisms of GE but on the mechanisms of levodopa uptake.

    Place, publisher, year, edition, pages
    Scientific Research Publishing, 2017
    National Category
    Neurology Gastroenterology and Hepatology Anesthesiology and Intensive Care Surgery Cardiac and Cardiovascular Systems
    Identifiers
    urn:nbn:se:liu:diva-136685 (URN)10.4236/apd.2017.61001 (DOI)
    Available from: 2017-04-20 Created: 2017-04-20 Last updated: 2018-01-12
    2. The Effect of Peripheral Enzyme Inhibitors on Levodopa Concentrations in Blood and CSF
    Open this publication in new window or tab >>The Effect of Peripheral Enzyme Inhibitors on Levodopa Concentrations in Blood and CSF
    Show others...
    2010 (English)In: Movement Disorders, ISSN 0885-3185, E-ISSN 1531-8257, Vol. 25, no 3, p. 363-367Article in journal (Refereed) Published
    Abstract [en]

    Levodopa combined with a dopa-decarboxylase inhibitor, such as carbidopa. shifts the metabolism to the COMT pathway. Adding the peripheral acting COMT inhibitor entacapone provides improvement for patients with PD suffering from motor fluctuations. We studied the effects of the enzyme inhibitors entacapone and carbidopa on the levodopa concentrations in CSF and in blood. Five PD patients with wearing-off underwent lumbar drainage and intravenous microdialysis. Samples were taken 12 h daily for 3 days. Day I; intravenous levodopa was given, day 2; additional oral entacapone 200 mg tid, day 3; additional oral entacapone 200 mg bid and carbidopa 25 mg bid. Levodopa in CSF and in dialysates was analysed. The AUC for levodopa increased both in blood and CSF when additional entacapone was given alone and in combination with carbidopa. The C-max of levodopa in both CSF and blood increased significantly. Additional entacapone to levodopa therapy gives an increase of C-max in CSF and in blood. The increase is more evident when entacapone is combined with carbidopa.

    Place, publisher, year, edition, pages
    John Wiley & Sons, 2010
    Keywords
    Parkinsons Disease, levodopa, continuous infusion, COMT
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-54855 (URN)10.1002/mds.22613 (DOI)000276136900016 ()
    Available from: 2010-04-16 Created: 2010-04-16 Last updated: 2018-01-12
    3. Neurotransmitter levels in basal ganglia during levodopa and deep brain stimulation treatment in Parkinson’s disease
    Open this publication in new window or tab >>Neurotransmitter levels in basal ganglia during levodopa and deep brain stimulation treatment in Parkinson’s disease
    Show others...
    2014 (English)In: Neurology and Clinical Neuroscience, ISSN 2049-4173, Vol. 2, no 5, p. 149-155Article in journal (Refereed) Published
    Abstract [en]

    Background The mechanism by which deep brain stimulation of the nucleus subthalamicus improves Parkinson’s disease symptoms remains unclear. In a previous perioperative study, we showed that there might be alterations of neurotransmitter levels in the globus pallidum interna during deep brain stimulation of the nucleus subthalamicus. Aim In this study, we examined whether deep brain stimulation of the nucleus subthalamicus and levodopa infusion interact and affect the levels of neurotransmitters. Methods Five patients with advanced Parkinson’s disease took part in the study. During subthalamic nucleus surgery, microdialysis catheters were inserted bilaterally in the globus pallidum interna and unilaterally in the right putamen. A study protocol was set up and was followed for 3 days. Levodopa infusion with and without concomitant bilateral deep brain stimulation of the nucleus subthalamicus was also carried out. Results The putaminal dopamine levels increased during deep brain stimulation of the nucleus subthalamicus. In addition, an increase of gamma amino buturic acid concentrations in the globus pallidum interna during deep brain stimulation of the nucleus subthalamicus and during levodopa infusion was found. Conclusions These findings provide evidence that the subthalamic nucleus has a direct action on the substantia nigra pars compacta, and that deep brain stimulation of the nucleus subthalamicus might indirectly release putaminal dopamine. There is also evidence that deep brain stimulation of the nucleus subthalamicus interferes with levodopa therapy resulting in higher levels of levodopa in the brain, explaining why it is possible to decrease levodopa medication after deep brain stimulation surgery.

    Place, publisher, year, edition, pages
    John Wiley & Sons, 2014
    Keywords
    deep brain stimulation, levodopa, microdialysis, neurotransmitters, Parkinson
    National Category
    Medical Bioscience Medical Biotechnology Basic Medicine
    Identifiers
    urn:nbn:se:liu:diva-113590 (URN)10.1111/ncn3.109 (DOI)
    Available from: 2015-01-23 Created: 2015-01-23 Last updated: 2018-01-12Bibliographically approved
    4. Levodopa Pharmacokinetics in Brain after Both Oral and Intravenous Levodopa in One Patient with Advanced Parkinson’s Disease
    Open this publication in new window or tab >>Levodopa Pharmacokinetics in Brain after Both Oral and Intravenous Levodopa in One Patient with Advanced Parkinson’s Disease
    2017 (English)In: Advances in Parkinsons Disease, ISSN 2169-9712, Vol. 6, no 2, p. 52-66Article in journal (Refereed) Published
    Abstract [en]

    Objective: One patient received oral levodopa during a study aiming for better understanding of the basal ganglia and of the mechanisms of deep brain stimulation of the subthalamic nucleus (STN DBS) with and without intravenous (IV) levodopa infusion in patients with Parkinson’s disease (PD). The results from oral and IV levodopa treatment are presented.

    Methods: Five patients with advanced PD were included in the original study. During planned STN DBS surgery microdialysis probes were implanted in the right putamen and in the right and left globus pallidus interna (Gpi). During the study, microdialysis was performed continuously and STN DBS, with and without IV levodopa infusion, was performed according to a specific protocol. After DBS surgery, but before STN DBS was started, one patient received oral levodopa/ benserazide and entacapone tablets out of protocol due to distressing parkinsonism.

    Results: The levodopa levels increased prompt in the central nervous system after the first PD medication intakes but declined after the last. Immediately the levodopa seemed to be metabolized to dopamine (DA) since the levels of DA correlated well with levodopa concentrations. Left STN DBS seemed to further increase DA levels in left Gpi while right STN DBS seemed to increase DA levels in the right putamen and right Gpi. There was no obvious effect on levodopa levels.

    Conclusions: The results indicate that PD patients still have capacity to metabolize levodopa to DA despite advanced disease with on-off symptoms and probably pronounced nigral degeneration. STN DBS seems to increase DA levels with a more pronounced effect on ipsilateral structures in striatum.

    Place, publisher, year, edition, pages
    Scientific Research Publishing Inc, 2017
    Keywords
    Parkinson’s Disease, Levodopa, Dopamine, Brain, Microdialysis, Deep Brain Stimulation
    National Category
    Neurology Cardiac and Cardiovascular Systems Gastroenterology and Hepatology Anesthesiology and Intensive Care Other Clinical Medicine
    Identifiers
    urn:nbn:se:liu:diva-139251 (URN)10.4236/apd.2017.62006 (DOI)
    Available from: 2017-07-07 Created: 2017-07-07 Last updated: 2018-01-12Bibliographically approved
  • 38.
    Nord, Maria
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Local Health Care Services in Central Östergötland, Department of Neurology.
    Kullman, Anita
    Linköping University, Faculty of Medicine and Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science.
    Hannestad, Ulf
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Dizdar Segrell, Nil
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Local Health Care Services in Central Östergötland, Department of Neurology.
    Is Levodopa Pharmacokinetics in Patients with Parkinson’s Disease Depending on Gastric Emptying?2017In: Advances in Parkinsons Disease, ISSN 2169-9712, Vol. 06, no 01Article in journal (Refereed)
    Abstract [en]

    Levodopa uptake from the gastrointestinal tract in patients with Parkinson’s disease (PD) can be affected by delayed gastric emptying (GE). This might lead to fluctuating levodopa levels resulting in increased motor fluctuations. Continuous dopaminergic stimulation (CDS) improves motor fluctuations and could be a result of smoothening in levodopa uptake. In this study we wanted to study the levodopa pharmacokinetics peripherally in PD patients with motor fluctuations and investigate the relation between levodopa uptake and GE and the effect of CDS. PD patients with wearing off (group 1) and on-off syndrome (group 2) were included. Breath tests were performed to evaluate the half time (T1/2) of GE. Concomitantly 1 tablet of Madopark® was given and the levodopa concentrations in blood and subcutaneous (SC) tissue were analyzed for both groups. Group 2 was then given a 10-d continuous intravenous levodopa treatment and the tests were repeated. Higher levels of levodopa in group 1 compared to group 2 in blood (p = 0.014) were seen. The GE was delayed in both group 1 (p < 0.001) and group 2 (p < 0.05) compared to a reference group with healthy volunteers with T1/2 median values 105 and 78 min vs. 72 min. There was no difference in GE between the two PD groups (p = 0.220) or in group 2 before and after infusion period (p = 0.861). CDS resulted in lower levodopa levels in blood (p < 0.001) and SC tissue (p < 0.01). In conclusion, PD patients in early complication phase have a more favourable levodopa uptake than patients later in disease. We found delayed GE in PD patients with motor fluctuations but no obvious relation between GE and levodopa uptake or GE and PD stage. The effect of CDS indicates no effect of CDS on the mechanisms of GE but on the mechanisms of levodopa uptake.

  • 39.
    Nuttall, Alfred L.
    et al.
    Oregon Hlth and Sci Univ, OR 97239 USA.
    Ricci, Anthony J.
    Stanford Univ, CA 94025 USA; Stanford Univ, CA 94025 USA.
    Burwood, George
    Oregon Hlth and Sci Univ, OR 97239 USA.
    Harte, James M.
    Tech Univ Denmark, Denmark.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Speech language pathology, Audiology and Otorhinolaryngology. Linköping University, Faculty of Medicine and Health Sciences.
    Caye-Thomasen, Per
    Copenhagen Univ Hosp, Denmark.
    Ren, Tianying
    Oregon Hlth and Sci Univ, OR 97239 USA.
    Ramamoorthy, Sripriya
    Indian Inst Technol, India.
    Zhang, Yuan
    Oregon Hlth and Sci Univ, OR 97239 USA.
    Wilson, Teresa
    Oregon Hlth and Sci Univ, OR 97239 USA.
    Lunner, Thomas
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research. Oticon AS, Denmark.
    Moore, Brian C. J.
    Univ Cambridge, England.
    Fridberger, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Oregon Hlth and Sci Univ, OR 97239 USA.
    A mechanoelectrical mechanism for detection of sound envelopes in the hearing organ2018In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 9, article id 4175Article in journal (Refereed)
    Abstract [en]

    To understand speech, the slowly varying outline, or envelope, of the acoustic stimulus is used to distinguish words. A small amount of information about the envelope is sufficient for speech recognition, but the mechanism used by the auditory system to extract the envelope is not known. Several different theories have been proposed, including envelope detection by auditory nerve dendrites as well as various mechanisms involving the sensory hair cells. We used recordings from human and animal inner ears to show that the dominant mechanism for envelope detection is distortion introduced by mechanoelectrical transduction channels. This electrical distortion, which is not apparent in the sound-evoked vibrations of the basilar membrane, tracks the envelope, excites the auditory nerve, and transmits information about the shape of the envelope to the brain.

  • 40.
    Nyström, Sofie
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Vahdat Shariat Panahi, Aida
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Nilsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Westermark, Per
    d Department of Immunology , Genetics and Pathology, Uppsala University , Uppsala , Sweden.
    Westermark, Gunilla T.
    e Department of Medical Cell Biology , Uppsala University , Uppsala , Sweden.
    Hammarström, Per
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Lundmark, Katarzyna
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Clinical pathology.
    Seed-dependent templating of murine AA amyloidosis2017In: Amyloid: Journal of Protein Folding Disorders, ISSN 1350-6129, E-ISSN 1744-2818, Vol. 24, no sup1, p. 140-141Article in journal (Other academic)
    Abstract [en]

    n/a

  • 41.
    Orfanidis, Kyriakos
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Dermatology and Venerology.
    Wäster, Petra
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Lundmark, Katarzyna
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Clinical pathology.
    Rosdahl, Inger
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Dermatology and Venerology.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Evaluation of tubulin β-3 as a novel senescence-associated gene in melanocytic malignant transformation.2017In: Pigment Cell & Melanoma Research, ISSN 1755-1471, E-ISSN 1755-148X, Vol. 30, no 2, p. 243-254Article in journal (Refereed)
    Abstract [en]

    Malignant melanoma might develop from melanocytic nevi in which the growth-arrested state has been broken. We analyzed the gene expression of young and senescent human melanocytes in culture and compared the gene expression data with a dataset from nevi and melanomas. A concordant altered gene expression was identified in 84 genes when comparing the growth-arrested samples with proliferating samples. TUBB3, which encodes the microtubule protein tubulin β-3, showed a decreased expression in senescent melanocytes and nevi and was selected for further studies. Depletion of tubulin β-3 caused accumulation of cells in the G2/M phase and decreased proliferation and migration. Immunohistochemical assessment of tubulin β-3 in benign lesions revealed strong staining in the superficial part of the intradermal components, which faded with depth. In contrast, primary melanomas exhibited staining without gradient in a disordered pattern and strong staining of the invasive front. Our results describe an approach to find clinically useful diagnostic biomarkers to more precisely identify cutaneous malignant melanoma and present tubulin β-3 as a candidate marker. This article is protected by copyright. All rights reserved.

  • 42.
    Osman, Ayman
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Autophagy in Peripheral Neuropathy2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Peripheral neuropathy includes a wide range of diseases affecting millions around the world, and many of these diseases have unknown etiology. Peripheral neuropathy in diabetes represents a large proportion of peripheral neuropathies. Nerve damage can also be caused by trauma. Peripheral neuropathies are a significant clinical problem and efficient treatments are largely lacking. In the case of a transected nerve, different methods have been used to repair or reconstruct the nerve, including the use of nerve conduits, but functional recovery is usually poor.

    Autophagy, a cellular mechanism that recycles damaged proteins, is impaired in the brain in many neurodegenerative diseases affecting animals and humans. No research, however, has investigated the presence of autophagy in the human peripheral nervous system. In this study, I present the first structural evidence of autophagy in human peripheral nerves. I also show that the density of autophagy structures is higher in peripheral nerves of patients with chronic idiopathic axonal polyneuropathy (CIAP) and inflammatory neuropathy than in controls. The density of these structures increases with the severity of the neuropathy.

    In animal model, using Goto-Kakizaki (GK) rats with diabetes resembling human type 2 diabetes, activation of autophagy by local administration of rapamycin incorporated in collagen conduits that were used for reconnection of the transected sciatic nerve led to an increase in autophagy proteins LC3 and a decrease in p62 suggesting that the autophagic flux was activated. In addition, immunoreactivity of neurofilaments, which are parts of the cytoskeleton of axons, was increased indicating increased axonal regeneration. I also show that many proteins involved in axonal regeneration and cell survival were up-regulated by rapamycin in the injured sciatic nerve of GK rats four weeks after injury.

    Taken together, these findings provide new knowledge about the involvement of autophagy in neuropathy and after peripheral nerve injury and reconstruction using collagen conduits.

    List of papers
    1. Autophagy in the posterior interosseous nerve of patients with type 1 and type 2 diabetes mellitus: an ultrastructural study
    Open this publication in new window or tab >>Autophagy in the posterior interosseous nerve of patients with type 1 and type 2 diabetes mellitus: an ultrastructural study
    2015 (English)In: Diabetologia, ISSN 0012-186X, E-ISSN 1432-0428, Vol. 58, no 3, p. 625-632Article in journal (Refereed) Published
    Abstract [en]

    We addressed the question of whether the autophagy pathway occurs in human peripheral nerves and whether this pathway is associated with peripheral neuropathy in diabetes mellitus. By using electron microscopy, we evaluated the presence of autophagy-related structures and neuropathy in the posterior interosseous nerve of patients who had undergone carpal tunnel release and had type 1 or type 2 diabetes mellitus, and in patients with no diabetes (controls). Autophagy-related ultrastructures were observed in the samples taken from all patients of the three groups. The number of autophagy-associated structures was significantly higher (p less than 0.05) in the nerves of patients with type 1 than type 2 diabetes. Qualitative and quantitative evaluations of fascicle area, diameter of myelinated and unmyelinated nerve fibres, the density of myelinated and unmyelinated fibres and the g-ratio of myelinated fibres were performed. We found degeneration and regeneration of a few myelinated axons in controls, and a well-developed neuropathy with the loss of large myelinated axons and the presence of many small ones in patients with diabetes. The pathology in type 1 diabetes was more extensive than in type 2 diabetes. The results of this study show that the human peripheral nerves have access to the autophagy machinery, and this pathway may be regulated differently in type 1 and type 2 diabetes; insulin, presence of extensive neuropathy, and/or other factors such as duration of diabetes and HbA(1c) level may underlie this differential regulation.

    Place, publisher, year, edition, pages
    Springer Verlag (Germany), 2015
    Keywords
    Autophagy; Diabetes; Electron microscopy; Human; Neuropathy; Peripheral nerve
    National Category
    Clinical Medicine
    Identifiers
    urn:nbn:se:liu:diva-115314 (URN)10.1007/s00125-014-3477-4 (DOI)000349244100024 ()25523623 (PubMedID)
    Available from: 2015-03-13 Created: 2015-03-13 Last updated: 2017-12-04
    2. Study of Autophagy and Microangiopathy in Sural Nerves of Patients with Chronic Idiopathic Axonal Polyneuropathy.
    Open this publication in new window or tab >>Study of Autophagy and Microangiopathy in Sural Nerves of Patients with Chronic Idiopathic Axonal Polyneuropathy.
    Show others...
    2016 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 9, article id e0163427Article in journal (Refereed) Published
    Abstract [en]

    Twenty-five percent of polyneuropathies are idiopathic. Microangiopathy has been suggested to be a possible pathogenic cause of chronic idiopathic axonal polyneuropathy (CIAP). Dysfunction of the autophagy pathway has been implicated as a marker of neurodegeneration in the central nervous system, but the autophagy process is not explored in the peripheral nervous system. In the current study, we examined the presence of microangiopathy and autophagy-related structures in sural nerve biopsies of 10 patients with CIAP, 11 controls with inflammatory neuropathy and 10 controls without sensory polyneuropathy. We did not find any significant difference in endoneurial microangiopathic markers in patients with CIAP compared to normal controls, though we did find a correlation between basal lamina area thickness and age. Unexpectedly, we found a significantly larger basal lamina area thickness in patients with vasculitic neuropathy. Furthermore, we found a significantly higher density of endoneurial autophagy-related structures, particularly in patients with CIAP but also in patients with inflammatory neuropathy, compared to normal controls. It is unclear if the alteration in the autophagy pathway is a consequence or a cause of the neuropathy. Our results do not support the hypothesis that CIAP is primarily caused by a microangiopathic process in endoneurial blood vessels in peripheral nerves. The significantly higher density of autophagy structures in sural nerves obtained from patients with CIAP and inflammatory neuropathy vs. controls indicates the involvement of this pathway in neuropathy, particularly in CIAP, since the increase in density of autophagy-related structures was more pronounced in patients with CIAP than those with inflammatory neuropathy. To our knowledge this is the first report investigating signs of autophagy process in peripheral nerves in patients with CIAP and inflammatory neuropathy.

    Place, publisher, year, edition, pages
    : San Francisco, CA : Public Library of Science, 2016
    National Category
    Rheumatology and Autoimmunity
    Identifiers
    urn:nbn:se:liu:diva-132168 (URN)10.1371/journal.pone.0163427 (DOI)000383893500033 ()27662650 (PubMedID)
    Note

    Funding agencies: patient association for neurological disorders in Sweden; NeurofoErbundet(NHR-Foundation); foundation Promobilia, Sweden

    Available from: 2016-10-19 Created: 2016-10-19 Last updated: 2017-11-29Bibliographically approved
  • 43.
    Ottosson, Nina
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Molecular Mechanisms of Resin Acids and Their Derivatives on the Opening of a Potassium Channel2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Voltage-gated ion channels play fundamental roles in excitable cells, such as neurons, where they enable electric signaling. Normally, this signaling is well controlled, but brain damage, alterations in the ionic composition of the extracellular solution, or dysfunctional ion channels can increase the electrical excitability thereby causing epilepsy. Voltage-gated ion channels are obvious targets for antiepileptic drugs, and, as a rule of thumb, excitability is dampened either by closing voltagegated sodium channels (Nav channels) or by opening voltage-gated potassium channels (Kv channels). For example, several classical antiepileptic drugs block the ion-conducting pore of Nav channels. Despite the large number of existing antiepileptic drugs, one third of the patients with epilepsy suffer from intractable or pharmacoresistant seizures.

    Our research group has earlier described how different polyunsaturated fatty acids (PUFAs) open a Kv channel by binding close to the voltage sensor and, from this position, electrostatically facilitate the movement of the voltage-sensor, thereby opening the channel. However, PUFAs affect a wide range of ion channels, making it difficult to use them as pharmaceutical drugs; it would be desirable to find smallmolecule compounds with an electrostatic, PUFA-like mechanism of action. The aim of the research leading to this thesis was to find, characterize, and refine drug candidates capable of electrostatically opening a Kv channel.

    The majority of the experiments were performed on the cloned Shaker Kv channel, expressed in oocytes from the frog Xenopus laevis, and the channel activity was explored with the two-electrode voltage-clamp technique. By systematically mutating the extracellular end of the channel’s voltage sensor, we constructed a highly PUFAsensitive channel, called the 3R channel. Such a channel is a useful tool in the search for electrostatic Kv-channel openers. We found that resin acids, naturally occurring in tree resins, act as electrostatic Shaker Kv channel openers. To explore the structure-activity relationship in detail, we synthesized 120 derivatives, whereof several were potent Shaker Kv channel openers. We mapped a common resin acidbinding site to a pocket formed by the voltage sensor, the channel’s third transmembrane segment, and the lipid membrane, a principally new binding site for small-molecule compounds. Further experiments showed that there are specific interactions between the compounds and the channel, suggesting promises for further drug development. Several of the most potent Shaker Kv channel openers also dampened the excitability in dorsal-root-ganglion neurons from mice, elucidating the pharmacological potency of these compounds. In conclusion, we have found that resin-acid derivatives are robust Kv-channel openers and potential drug candidates against diseases caused by hyperexcitability, such as epilepsy.

    List of papers
    1. Drug-induced ion channel opening tuned by the voltage sensor charge profile
    Open this publication in new window or tab >>Drug-induced ion channel opening tuned by the voltage sensor charge profile
    2014 (English)In: The Journal of General Physiology, ISSN 0022-1295, E-ISSN 1540-7748, Vol. 143, no 2, p. 173-182Article in journal (Refereed) Published
    Abstract [en]

    Polyunsaturated fatty acids modulate the voltage dependence of several voltage-gated ion channels, thereby being potent modifiers of cellular excitability. Detailed knowledge of this molecular mechanism can be used in designing a new class of small-molecule compounds against hyperexcitability diseases. Here, we show that arginines on one side of the helical K-channel voltage sensor S4 increased the sensitivity to docosahexaenoic acid (DHA), whereas arginines on the opposing side decreased this sensitivity. Glutamates had opposite effects. In addition, a positively charged DHA-like molecule, arachidonyl amine, had opposite effects to the negatively charged DHA. This suggests that S4 rotates to open the channel and that DHA electrostatically affects this rotation. A channel with arginines in positions 356, 359, and 362 was extremely sensitive to DHA: 70 mu M DHA at pH 9.0 increased the current greater than500 times at negative voltages compared with wild type (WT). The small-molecule compound pimaric acid, a novel Shaker channel opener, opened the WT channel. The 356R/359R/362R channel drastically increased this effect, suggesting it to be instrumental in future drug screening.

    Place, publisher, year, edition, pages
    Rockefeller University Press, 2014
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-105035 (URN)10.1085/jgp.201311087 (DOI)000330628500006 ()
    Available from: 2014-03-06 Created: 2014-03-06 Last updated: 2018-01-25
    2. Resin-acid derivatives as potent electrostatic openers of voltage-gated K channels and suppressors of neuronal excitability
    Open this publication in new window or tab >>Resin-acid derivatives as potent electrostatic openers of voltage-gated K channels and suppressors of neuronal excitability
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    2015 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, no 13278Article in journal (Refereed) Published
    Abstract [en]

    Voltage-gated ion channels generate cellular excitability, cause diseases when mutated, and act as drug targets in hyperexcitability diseases, such as epilepsy, cardiac arrhythmia and pain. Unfortunately, many patients do not satisfactorily respond to the present-day drugs. We found that the naturally occurring resin acid dehydroabietic acid (DHAA) is a potent opener of a voltage-gated K channel and thereby a potential suppressor of cellular excitability. DHAA acts via a non-traditional mechanism, by electrostatically activating the voltage-sensor domain, rather than directly targeting the ion-conducting pore domain. By systematic iterative modifications of DHAA we synthesized 71 derivatives and found 32 compounds more potent than DHAA. The most potent compound, Compound 77, is 240 times more efficient than DHAA in opening a K channel. This and other potent compounds reduced excitability in dorsal root ganglion neurons, suggesting that resin-acid derivatives can become the first members of a new family of drugs with the potential for treatment of hyperexcitability diseases.

    Place, publisher, year, edition, pages
    Nature Publishing Group: Open Access Journals - Option C / Nature Publishing Group, 2015
    National Category
    Clinical Medicine Chemical Sciences
    Identifiers
    urn:nbn:se:liu:diva-121307 (URN)10.1038/srep13278 (DOI)000359905300001 ()26299574 (PubMedID)
    Note

    Funding Agencies|Swedish Research Council; Swedish Brain Foundation; Swedish Heart-Lung Foundation; ALF; County Council of Ostergotland

    Available from: 2015-09-16 Created: 2015-09-14 Last updated: 2018-01-25Bibliographically approved
  • 44.
    Ottosson, Nina
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Silverå Ejneby, Malin
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Wu, Xiongyu
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Yazdi, Samira
    Stockholm University, Sweden.
    Konradsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Lindahl, Erik
    Stockholm University, Sweden; KTH Royal Institute Technology, Sweden.
    Elinder, Fredrik
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    A drug pocket at the lipid bilayer-potassium channel interface2017In: Science Advances, ISSN 0036-8156, E-ISSN 2375-2548, Vol. 3, no 10, article id e1701099Article in journal (Refereed)
    Abstract [en]

    Many pharmaceutical drugs against neurological and cardiovascular disorders exert their therapeutic effects by binding to specific sites on voltage-gated ion channels of neurons or cardiomyocytes. To date, all molecules targeting known ion channel sites bind to protein pockets that are mainly surrounded by water. We describe a lipid-protein drug-binding pocket of a potassium channel. We synthesized and electrophysiologically tested 125 derivatives, analogs, and related compounds to dehydroabietic acid. Functional data in combination with docking and molecular dynamics simulations mapped a binding site for small-molecule compounds at the interface between the lipid bilayer and the transmembrane segments S3 and S4 of the voltage-sensor domain. This fundamentally new binding site for small-molecule compounds paves the way for the design of new types of drugs against diseases caused by altered excitability.

  • 45.
    Pantazis, Antonios
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Univ Calif Los Angeles, CA 90095 USA.
    Westerberg, Karin
    Amgen Inc, CA 91320 USA.
    Althoff, Thorsten
    Univ Calif Los Angeles, CA 90095 USA.
    Abramson, Jeff
    Univ Calif Los Angeles, CA 90095 USA.
    Olcese, Riccardo
    Univ Calif Los Angeles, CA 90095 USA.
    Harnessing photoinduced electron transfer to optically determine protein sub-nanoscale atomic distances2018In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 9, article id 4738Article in journal (Refereed)
    Abstract [en]

    Proteins possess a complex and dynamic structure, which is influenced by external signals and may change as they perform their biological functions. We present an optical approach, distance-encoding photoinduced electron transfer (DEPET), capable of the simultaneous study of protein structure and function. An alternative to FRET-based methods, DEPET is based on the quenching of small conjugated fluorophores by photoinduced electron transfer: a reaction that requires contact of the excited fluorophore with a suitable electron donor. This property allows DEPET to exhibit exceptional spatial and temporal resolution capabilities in the range pertinent to protein conformational change. We report the first implementation of DEPET on human large-conductance K+ (BK) channels under voltage clamp. We describe conformational rearrangements underpinning BK channel sensitivity to electrical excitation, in conducting channels expressed in living cells. Finally, we validate DEPET in synthetic peptide length standards, to evaluate its accuracy in measuring sub-and near-nanometer intramolecular distances.

  • 46.
    Rajan, Meenu Rohini
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Nyman, Elin
    Linköping University, Department of Biomedical Engineering, Division of Biomedical Engineering. Linköping University, Faculty of Science & Engineering.
    Brannmark, Cecilia
    Univ Gothenburg, Sweden.
    Olofsson, Charlotta S.
    Univ Gothenburg, Sweden.
    Strålfors, Peter
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Inhibition of FOXO1 transcription factor in primary human adipocytes mimics the insulin-resistant state of type 2 diabetes2018In: Biochemical Journal, ISSN 0264-6021, E-ISSN 1470-8728, Vol. 475, p. 1807-1820Article in journal (Refereed)
    Abstract [en]

    Type 2 diabetes is characterized by insulin resistance in the expanding adipose tissue of obesity. The insulin resistance manifests in human adipocytes as system-wide impairment of insulin signalling. An exception is the regulation of transcription factor FOXO1 (forkhead box protein O1), which is phosphorylated downstream of mTORC2 (mammalian/mechanistic target of rapamycin in complex with raptor) and is therefore not exhibiting impaired response to insulin. However, the abundance, and activity, of FOXO1 is reduced by half in adipocytes from patients with diabetes. To elucidate the effect of reduced FOXO1 activity, we here transduced human adipocytes with a dominant-negative construct of FOXO1 (DN-FOXO1). Inhibition of FOXO1 reduced the abundance of insulin receptor, glucose transporter-4, ribosomal protein S6, mTOR and raptor. Functionally, inhibition of FOXO1 induced an insulin-resistant state network-wide, a state that qualitatively and quantitatively mimicked adipocytes from patients with type 2 diabetes. In contrast, and in accordance with these effects of DN-FOXO1, overexpression of wild-type FOXO1 appeared to augment insulin signalling. We combined experimental data with mathematical modelling to show that the impaired insulin signalling in FOXO1-inhibited cells to a large extent can be explained by reduced mTORC1 activity - a mechanism that defines much of the diabetic state in human adipocytes. Our findings demonstrate that FOXO1 is critical for maintaining normal insulin signalling of human adipocytes.

  • 47.
    Renhorn, Jakob
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Conformational Changes during Potassium-Channel Gating2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Voltage-gated ion channels have a paramount importance in many physiological processes such as cell-to-cell communication, action potential-propagation, and cell motility. Voltage-gated ion channels are characterized by their ability to sense membrane voltage and to greatly change channel activity in response to small changes in the voltage. The ability to sense voltage resides in the four voltage-sensor domains (VSDs) surrounding the central ion-conducting pore. Membrane depolarization causes the inside of the membrane to become positively charged, electrostatically repelling the positively charged fourth transmembrane segment (S4), or voltage sensor, in the VSD, causing the voltage sensor to move outwards. This motion provides necessary energy to open the pore and allow ion conductivity. Prolonged channel activation leads to alterations in the selectivity filter which cease ion conductivity, in a process called slow inactivation. In this thesis, we investigated the movement of S4 during activation of the channel. We also studied the communication between the four subunits during activation as well as the communication between the pore domain and VSD during slow inactivation.

    We have shown that voltage sensors move approximately 12 Å outwards during activation. The positively charged amino acid residues in S4 create temporary salt bridges with negative counter-charges in the other segments of the VSD as it moves through a membrane. We have also shown that the movement of one of the four voltage sensors can affect the movement of the neighboring voltage sensors. When at least one voltage sensor has moved to an up-position, it stabilizes other voltage sensors in the up-position, increasing the energy required for the voltage sensor to return to the down position.

    We have also shown reciprocal communication between the pore domain and the VSDs. Alterations in the VSD or the interface between the pore and the VSD cause changes in the rate of slow inactivation. Likewise, modifications in the pore domain cause changes to the voltage-sensor movement. This indicates communication between the pore and the VSD during slow inactivation.

    The information from our work could be used to find new approaches when designing channel-modifying drugs for the treatment of diseases caused by increased neuronal excitability, such as chronic pain and epilepsy.

    List of papers
    1. Tracking a complete voltage-sensor cycle with metal-ion bridges
    Open this publication in new window or tab >>Tracking a complete voltage-sensor cycle with metal-ion bridges
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    2012 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 109, no 22, p. 8552-8557Article in journal (Refereed) Published
    Abstract [en]

    Voltage-gated ion channels open and close in response to changes in membrane potential, thereby enabling electrical signaling in excitable cells. The voltage sensitivity is conferred through four voltage-sensor domains (VSDs) where positively charged residues in the fourth transmembrane segment (S4) sense the potential. While an open state is known from the Kv1.2/2.1 X-ray structure, the conformational changes underlying voltage sensing have not been resolved. We present 20 additional interactions in one open and four different closed conformations based on metal-ion bridges between all four segments of the VSD in the voltage-gated Shaker K channel. A subset of the experimental constraints was used to generate Rosetta models of the conformations that were subjected to molecular simulation and tested against the remaining constraints. This achieves a detailed model of intermediate conformations during VSD gating. The results provide molecular insight into the transition, suggesting that S4 slides at least 12 angstrom along its axis to open the channel with a 3(10) helix region present that moves in sequence in S4 in order to occupy the same position in space opposite F290 from open through the three first closed states.

    Place, publisher, year, edition, pages
    National Academy of Sciences, 2012
    Keywords
    electrophysiology, inactivation, Xenopus oocytes, voltage clamp, conformational transition
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-78812 (URN)10.1073/pnas.1116938109 (DOI)000304881700044 ()