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  • 51.
    La Fleur, Linnea
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences.
    Johansson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Roberg, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Sinnescentrum, Department of ENT - Head and Neck Surgery UHL.
    A CD44(high)/EGFR(low) Subpopulation within Head and Neck Cancer Cell Lines Shows an Epithelial-Mesenchymal Transition Phenotype and Resistance to Treatment2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 9Article in journal (Refereed)
    Abstract [en]

    Mortality in head and neck squamous cell carcinoma (HNSCC) is high due to emergence of therapy resistance which results in local and regional recurrences that may have their origin in resistant cancer stem cells (CSCs) or cells with an epithelial-mesenchymal transition (EMT) phenotype. In the present study, we investigate the possibility of using the cell surface expression of CD44 and epidermal growth factor receptor (EGFR), both of which have been used as stem cell markers, to identify subpopulations within HNSCC cell lines that differ with respect to phenotype and treatment sensitivity. Three subpopulations, consisting of CD44(high)/EGFR(low), CD44(high)/EGFR(high) and CD44(low) cells, respectively, were collected by fluorescence-activated cell sorting. The CD44(high)/EGFR(low) population showed a spindle-shaped EMT-like morphology, while the CD44(low) population was dominated by cobblestone-shaped cells. The CD44(high)/EGFR(low) population was enriched with cells in G0/G1 and showed a relatively low proliferation rate and a high plating efficiency. Using a real time PCR array, 27 genes, of which 14 were related to an EMT phenotype and two with stemness, were found to be differentially expressed in CD44(high)/EGFR(low) cells in comparison to CD44(low) cells. Moreover, CD44(high)/EGFR(low) cells showed a low sensitivity to radiation, cisplatin, cetuximab and gefitinib, and a high sensitivity to dasatinib relative to its CD44(high)/EGFR(high) and CD44(low) counterparts. In conclusion, our results show that the combination of CD44 (high) and EGFR (low) cell surface expression can be used to identify a treatment resistant subpopulation with an EMT phenotype in HNSCC cell lines.

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  • 52.
    Larsson (Wäster), Petra
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Dermatology and Venerology . Linköping University, Faculty of Health Sciences.
    Andersson, Eva
    Linköping University, Department of Clinical and Experimental Medicine, Dermatology and Venerology . Linköping University, Faculty of Health Sciences.
    Johansson, Uno
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Rosdahl, Inger
    Linköping University, Department of Clinical and Experimental Medicine, Dermatology and Venerology . Linköping University, Faculty of Health Sciences.
    Ultraviolet A and B affect human melanocytes and keratinocytes differently. A study of oxidative alterations and apoptosis2005In: Experimental Dermatology, ISSN 0906-6705, Vol. 14, no 2, p. 117-123Article in journal (Refereed)
    Abstract [en]

    Ultraviolet (UV) radiation is an etiologic agent for malignant melanoma and non-melanoma skin cancer, but the spectral range responsible for tumor induction is still to be elucidated. In this study, we compared effects of UVA and UVB irradiation on normal human melanocytes (MCs) and keratinocytes (KCs) in vitro. We demonstrate that UVA irradiation induces immediate loss of reduced glutathione (GSH) in both MCs and KCs. Exposure to UVA also causes reduced plasma membrane stability, in both cell types, as estimated by fluorescein diacetate retention and flow cytometry. Furthermore, we noted reduction in proliferation and higher apoptosis frequency 24 h after UVA irradiation. UVB irradiation of KCs caused instant reduction of reduced GSH and impaired plasma membrane stability. We also found decline in proliferation and increased apoptosis after 24 h. In MCs, on the other hand, UVB had no effect on GSH level or plasma membrane stability, although increased apoptotic cell death and reduced proliferation was detected. In summary, MCs and KCs showed similar response towards UVA, while UVB had more pronounced effects on KCs as compared to MCs. These results might have implications for the induction of malignant melanoma and non-melanoma skin cancer.

  • 53.
    Larsson Wäster, Petra
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Dermatology and Venerology . Linköping University, Faculty of Health Sciences.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Rosdahl, Inger
    Linköping University, Department of Clinical and Experimental Medicine, Dermatology and Venerology . Linköping University, Faculty of Health Sciences.
    Ultraviolet (UV) A- and UVB-induced redox alterations and activation of nuclear factor-kappaB in human melanocytes - protective effects of alpha-tocopherol2006In: British Journal of Dermatology, ISSN 0007-0963, Vol. 155, no 2, p. 292-300Article in journal (Refereed)
    Abstract [en]

    Background Despite compelling evidence that ultraviolet (UV) irradiation causes melanoma the knowledge concerning reaction pathways and signalling transduction in melanocytes is still limited.

    Objectives To evaluate the protective capacity of α-tocopherol and β-carotene during UVA and UVB irradiation of human melanocytes in vitro.

    Methods Primary cultures of normal human melanocytes were irradiated by different wavelengths within the UV spectrum (UVA 6 J cm−2, UVB 60 mJ cm−2). Redox alterations and apoptosis were studied and the protective potential of α-tocopherol and β-carotene was evaluated.

    Results UVA and UVB irradiation decreased the intracellular concentration of reduced glutathione and activated the transcription factor nuclear factor (NF)-κB, detected as the increased level of the p65 subunit and translocation to the nucleus. This coincided with a rise in the level of γ-glutamyl-cysteine-synthetase, the rate-limiting enzyme of the glutathione synthesis. UVA and UVB caused apoptotic cell death as detected by nuclear fragmentation and caspase activation 24 h postirradiation. Pretreatment with α-tocopherol prevented UVA- and UVB-induced glutathione loss, NF-κB translocation and diminished apoptosis, but β-carotene did not show a similar protective capacity. Further, exposure to α-tocopherol by itself reduced cell proliferation rate.

    Conclusions UVA and UVB irradiation affected the intracellular redox state and increased the frequency of apoptosis in human melanocytes in vitro. α-Tocopherol might be a useful substance in protecting melanocytes from UV-induced damage.

  • 54. Order onlineBuy this publication >>
    Laskar, Amit
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Cell response to imaging contrast agents suggested for atherosclerotic plaque imaging2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Oxysterols are the major cytotoxic components of oxidized low-density lipoprotein (OxLDL) that accumulate in atherosclerotic plaques. Their uptake by macrophages ensue foam cell formation, atherogenesis and plaque progression. Magnetic resonance imaging (MRI) has grown as a modality to track such intra-plaque developments by using intracellular contrast agents. The focus of this study was to evaluate the effects of two contrast agents; manganese based mangafodipir (TeslascanTM) and iron based super-paramagnetic iron oxide nanoparticles (SPION, ResovistTM) on cell functions and examined their interaction with oxysterol laden cells.

    Mangafodipir has antioxidant property and provides protection against oxidative stress. The chemical structure of mangafodipir comprises of organic ligand fodipir (Dipyridoxyl diphosphate, Dp-dp) and Mn (manganese). Mangafodipir is readily metabolized within the body to manganese dipyridoxyl ethyldiamine (MnPLED) after an intravenous injection. MnPLED has superoxide dismutase (SOD) mimetic activity, and Dp-dp has iron chelating effects. The second contrast agent tested in this study is ResovistTM. These SPION are primarily ingested by macrophages and accumulated in lysosomes where they are gradually degraded ensuing increased cellular iron.

    In paper I, we examined whether the above-noted effects of mangafodipir could be utilized to prevent 7β-hydroxycholesterol (7βOH) induced cell death. We found that mangafodipir prevents 7βOH induced cell death by attenuating reactive oxygen species (ROS) and by preserving lysosomal membrane integrity and mitochondrial membrane potential.

    The second part of this study (paper II) was designed to identify the pharmacologically active part of mangafodipir, which exerts the above-noted effects. We compared the activity of parent compound (mangafodipir) with MnPLED and Dp-dp. We found that mangafodipir; MnPLED and Dp-dp provide similar cyto-protection against 7βOH induced cell death. These results suggest that MnPLED and Dp-dp both contribute to the pharmacologically active part of mangafodipir.

    In paper III, we aimed to examine the interaction of SPION with monocytes and macrophages exposed or not to atheroma relevant oxysterols. We demonstrate that SPION loading up-regulates cellular levels of cathepsin and ferritin and induces membranous ferroportin expression. Additionally, SPION incites secretion of ferritin and both pro-inflammatory and anti-inflammatory cytokines. Moreover, exposure to oxysterols resulted in a reduced SPION uptake by cells, which may lead to inefficient targeting of such cells. Although SPION uptake was reduced, the ingested amounts significantly up-regulated the expression of 7βOH induced cathepsin B, cathepsin L and ferritin in cells, which may further aggravate atherogenesis.

    The fourth part of the study (paper IV) was designed to examine the interaction of SPION with macrophage subtypes and compare the cellular effects of coated and uncoated iron-oxide nanoparticles. We found that iron in SPION induces a phenotypic shift in THP1 M2 macrophages towards a macrophage subtype characterized by upregulated intracellular levels of CD86, ferritin and cathepsin L. Differential levels of these proteins among macrophage subtypes might be important to sustain a functional plasticity. Additionally, uncoated iron-oxide nanoparticles induced dose dependent cell death in macrophages, which elucidates the potential cyto-toxicity of iron in iron-oxide nanoparticles.

    In conclusion, evidence is provided in this study that intracellular MRI contrast agents have the potential to modulate cell functions. The study reveals a therapeutic potential of mangafodipir, which could be utilized for future development of contrast agents with both diagnostic and curative potentials. Additionally, we found that surface coating in SPION may provide cell tolerance to iron toxicity by modulation of cellular iron metabolism and cell functions. Such alterations in cellular metabolism call for careful monitoring and also highlight new concepts for development of iron containing nanoparticles. A reduced uptake of SPION by atheroma relevant cells justifies development of functionalized SPION to target such cells in atherosclerotic plaques.

    List of papers
    1. Prevention of 7beta-hydroxycholesterol-induced cell death by mangafodipir is mediated through lysosomal and mitochondrial pathways
    Open this publication in new window or tab >>Prevention of 7beta-hydroxycholesterol-induced cell death by mangafodipir is mediated through lysosomal and mitochondrial pathways
    2010 (English)In: European Journal of Pharmacology, ISSN 0014-2999, E-ISSN 1879-0712, no 640, p. 124-128Article in journal (Refereed) Published
    Abstract [en]

    Mangafodipir, a MRI contrast agent, has been used as a viability marker in patients with myocardial infarction and showed vascular relaxation effect. It confers myocardial protection against oxidative stress. However mechanisms underlying such protection have not yet been investigated. In this investigation we first studied whether mangafodipir inhibits apoptosis induced by 7beta-hydroxycholesterol (7betaOH), a cytotoxic cholesterol oxidation product found in atherosclerotic lesions in humans and in heart of ethanol-fed rats. We then focused on whether mangafodipir influences the production of reactive oxygen species, lysosomal and mitochondrial membrane permeabilities in the cell model. Our results revealed that pre-treatment with mangafodipir (400microM) protected against cellular reactive oxygen species production, apoptosis, and permeabilization of lysosomal and mitochondrial membranes induced by 7betaOH. In conclusion, a novel effect of mangafodipir on 7betaOH-induced apoptosis is via reduction of cellular reactive oxygen species and stabilization of lysosomal and mitochondrial membranes. This is the first report to show the additional cytoprotective effect of mangafodipir, which may suggest possible use of the drug.

    Keywords
    Atherosclerosis, Apoptosis, Mangafodipir, Oxidized lipid, Oxidative stress
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-57355 (URN)10.1016/j.ejphar.2010.04.046 (DOI)20452343 (PubMedID)
    Available from: 2010-06-17 Created: 2010-06-17 Last updated: 2017-12-12
    2. Fodipir (Dp-dp) and its dephosphorylated derivative PLED are involved in mangafodipir mediated cyto-protection against 7β-hydroxycholesterol induced cell death
    Open this publication in new window or tab >>Fodipir (Dp-dp) and its dephosphorylated derivative PLED are involved in mangafodipir mediated cyto-protection against 7β-hydroxycholesterol induced cell death
    2013 (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Mangafodipir exerts pharmacological effects, including vascular relaxation and protection against oxidative stress and cell death induced by oxysterols. Additionally, mangafodipir has been proposed for cardiovascular imaging. The primary metabolite of mangafodipir, manganese dipyridoxyl ethyldiamine (MnPLED) and its constituent, dipyridoxyl diphosphate (Dp-dp) also known as fodipir, are pharmacologically active. However, whether they affect oxysterol induced cytotoxicity is currently unknown. In this study, we examine whether the mangafodipir metabolite affects 7β-hydroxycholesterol (7βOH) induced cell death and identify the underlying mechanisms. U937 cells were pre-treated or not with mangafodipir substrate (Ms) (200 μm), MnPLED (100 μM) or Dp-dp (100 μM) for 8 hours and then exposed to 7βOH (28 μM) for 18 hours. Our results revealed that pre-treatment with MnPLED or Dp-dp protected against 7βOH induced cellular reactive oxygen species (ROS) production, apoptosis, and lysosomal membrane permeabilization (LMP). MnPLED and Dpdp in par with Ms, confer protection against 7βOH induced cytotoxicity by reducing  cellular ROS and stabilization of lysosomal membrane. These results suggest that, fodipir is the active part in mangafodipir, which shows the noted effects and its activity is conserved in MnPLED. These results further confirm the cyto-protective effect of mangafodipir and justify its potential use as a cyto-protective adjuvant.

    Keywords
    Atherogenic, Apoptosis, Mangafodipir, Oxidative stress, Oxysterols
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-91996 (URN)
    Available from: 2013-05-07 Created: 2013-05-07 Last updated: 2013-05-07Bibliographically approved
    3. Degradation of superparamagnetic iron oxide nanoparticle-induced ferritin by lysosomal cathepsins and related immune response
    Open this publication in new window or tab >>Degradation of superparamagnetic iron oxide nanoparticle-induced ferritin by lysosomal cathepsins and related immune response
    Show others...
    2012 (English)In: Nanomedicine, ISSN 1743-5889, E-ISSN 1748-6963, Vol. 7, no 5, p. 705-717Article in journal (Refereed) Published
    Abstract [en]

    Aim: To examine the physiological impact of superparamagnetic iron oxide nanoparticles (SPIONs) on cell function and its interaction with oxysterol laden cells. Materials andamp; methods: Intracellular iron was determined by Prussian blue staining. Cellular ferritin, cathepsin L and ferroportin were analyzed by flow cytometry and fluorescence microscopy. Cytokine secretion was determined by ELISA and immunoblotting. Results: In U937 and THP 1 cells, we did not detect any loss of cell viability on SPION loading. Desferrioxamine prevents induction of both ferritin and cathepsin L by SPIONs. Inhibition of lysosomal cathepsins upregulates both endogenous- and SPION-induced ferritin. SPION loading induces membranous ferroportin and incites secretion of ferritin, TNF-alpha and IL-10. 7 beta-hydroxycholesterol exposure reduces SPION uptake by cells. Conclusion: SPION loading results in upregulation of lysosomal cathepsin, membranous ferroportin and ferritin degradation, which is associated with secretion of both pro- and anti-inflammatory cytokines. A reduced SPION uptake by oxysterol-laden cells may lead to a compromised MRI with elevated cathepsins and ferritin.

    Place, publisher, year, edition, pages
    Future Medicine, 2012
    Keywords
    atherosclerosis, cytokine, degradation, iron, lysosomal, monocyte, nanoparticle
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-78580 (URN)10.2217/nnm.11.148 (DOI)000304238300016 ()
    Note

    Funding Agencies|Swedish Heart Lung Foundation||research fund of Torsten och Ragnar Soderbergs||research fund of Stroke||research fund of Gamla Tjanarinnor||Linkoping University Hospital||

    Available from: 2012-06-15 Created: 2012-06-15 Last updated: 2017-12-07
    4. SPION primes THP1 derived M2 macrophages towards M1-like macrophages
    Open this publication in new window or tab >>SPION primes THP1 derived M2 macrophages towards M1-like macrophages
    2013 (English)In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 441, no 4, p. 737-742Article in journal (Refereed) Published
    Abstract [en]

    Potentially, cellular iron regulates functional plasticity in macrophages yet; interaction of functionally polarized macrophages with iron-oxide nanoparticles has never been studied. We found that monocyte differentiation alters cellular ferritin and cathepsin L levels and induces functional polarization in macrophages. Iron in super paramagnetic iron-oxide nanoparticle (SPION) induces a phenotypic shift in THP1 derived M2 macrophages towards a high CD86+ macrophage subtype. This phenotypic shift was accompanied by up-regulated intracellular levels of ferritin and cathepsin L in M2 macrophages, which we found as a characteristic hallmark of M1 macrophages. Atherogenic oxysterols reduce phagocytic activity in both macrophage subtypes and thus these cells may escape detection by ironoxide nanoparticles (INPs) in-vivo.

    Place, publisher, year, edition, pages
    Elsevier, 2013
    Keywords
    Cathepsin L; Ferritin; Iron-oxide nanoparticles; M1 and M2 macrophages; Oxysterols
    National Category
    Immunology
    Identifiers
    urn:nbn:se:liu:diva-91999 (URN)10.1016/j.bbrc.2013.10.115 (DOI)000328434800008 ()
    Available from: 2013-05-07 Created: 2013-05-07 Last updated: 2017-12-06Bibliographically approved
    Download full text (pdf)
    Cell response to imaging contrast agents suggested for atherosclerotic plaque imaging
    Download (pdf)
    omslag
  • 55.
    Laskar, Amit
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Andersson, Rolf G G
    Linköping University, Department of Medical and Health Sciences, Pharmacology. Linköping University, Faculty of Health Sciences.
    Li, Wei
    Linköping University, Department of Medical and Health Sciences, Pharmacology. Linköping University, Faculty of Health Sciences.
    Fodipir (Dp-dp) and its dephosphorylated derivative PLED are involved in mangafodipir mediated cyto-protection against 7β-hydroxycholesterol induced cell death2013Manuscript (preprint) (Other academic)
    Abstract [en]

    Mangafodipir exerts pharmacological effects, including vascular relaxation and protection against oxidative stress and cell death induced by oxysterols. Additionally, mangafodipir has been proposed for cardiovascular imaging. The primary metabolite of mangafodipir, manganese dipyridoxyl ethyldiamine (MnPLED) and its constituent, dipyridoxyl diphosphate (Dp-dp) also known as fodipir, are pharmacologically active. However, whether they affect oxysterol induced cytotoxicity is currently unknown. In this study, we examine whether the mangafodipir metabolite affects 7β-hydroxycholesterol (7βOH) induced cell death and identify the underlying mechanisms. U937 cells were pre-treated or not with mangafodipir substrate (Ms) (200 μm), MnPLED (100 μM) or Dp-dp (100 μM) for 8 hours and then exposed to 7βOH (28 μM) for 18 hours. Our results revealed that pre-treatment with MnPLED or Dp-dp protected against 7βOH induced cellular reactive oxygen species (ROS) production, apoptosis, and lysosomal membrane permeabilization (LMP). MnPLED and Dpdp in par with Ms, confer protection against 7βOH induced cytotoxicity by reducing  cellular ROS and stabilization of lysosomal membrane. These results suggest that, fodipir is the active part in mangafodipir, which shows the noted effects and its activity is conserved in MnPLED. These results further confirm the cyto-protective effect of mangafodipir and justify its potential use as a cyto-protective adjuvant.

  • 56.
    Laskar, Amit
    et al.
    Linköping University, Department of Medical and Health Sciences, Pharmacology. Linköping University, Faculty of Health Sciences.
    Eilertsen, Jonas
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Li, Wei
    Linköping University, Department of Medical and Health Sciences, Pharmacology. Linköping University, Faculty of Health Sciences.
    Yuan, Xi-Ming
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Occupational and Environmental Medicine Center.
    SPION primes THP1 derived M2 macrophages towards M1-like macrophages2013In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 441, no 4, p. 737-742Article in journal (Refereed)
    Abstract [en]

    Potentially, cellular iron regulates functional plasticity in macrophages yet; interaction of functionally polarized macrophages with iron-oxide nanoparticles has never been studied. We found that monocyte differentiation alters cellular ferritin and cathepsin L levels and induces functional polarization in macrophages. Iron in super paramagnetic iron-oxide nanoparticle (SPION) induces a phenotypic shift in THP1 derived M2 macrophages towards a high CD86+ macrophage subtype. This phenotypic shift was accompanied by up-regulated intracellular levels of ferritin and cathepsin L in M2 macrophages, which we found as a characteristic hallmark of M1 macrophages. Atherogenic oxysterols reduce phagocytic activity in both macrophage subtypes and thus these cells may escape detection by ironoxide nanoparticles (INPs) in-vivo.

  • 57.
    Laskar, Amit
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Ghosh, M
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Khattak, S I
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Li, W
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Yuan, X
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    DEGRADATION OF SPIO INDUCED FERRITIN BY LYSOSOMAL CATHEPSINS, RELATED IMMUNE RESPONSE AND INTERACTION WITH ATHEROMA RELEVANT CELLS in ATHEROSCLEROSIS SUPPLEMENTS, vol 12, issue 1, pp 175-1752011In: ATHEROSCLEROSIS SUPPLEMENTS, Elsevier Science B.V., Amsterdam. , 2011, Vol. 12, no 1, p. 175-175Conference paper (Refereed)
    Abstract [en]

    n/a

  • 58.
    Laskar, Amit
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Ghosh, Moumita
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Iqbal Khattak, Sikander
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Li, Wei
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Yuan, Xi-Ming
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Occupational and Environmental Medicine Center.
    Degradation of superparamagnetic iron oxide nanoparticle-induced ferritin by lysosomal cathepsins and related immune response2012In: Nanomedicine, ISSN 1743-5889, E-ISSN 1748-6963, Vol. 7, no 5, p. 705-717Article in journal (Refereed)
    Abstract [en]

    Aim: To examine the physiological impact of superparamagnetic iron oxide nanoparticles (SPIONs) on cell function and its interaction with oxysterol laden cells. Materials andamp; methods: Intracellular iron was determined by Prussian blue staining. Cellular ferritin, cathepsin L and ferroportin were analyzed by flow cytometry and fluorescence microscopy. Cytokine secretion was determined by ELISA and immunoblotting. Results: In U937 and THP 1 cells, we did not detect any loss of cell viability on SPION loading. Desferrioxamine prevents induction of both ferritin and cathepsin L by SPIONs. Inhibition of lysosomal cathepsins upregulates both endogenous- and SPION-induced ferritin. SPION loading induces membranous ferroportin and incites secretion of ferritin, TNF-alpha and IL-10. 7 beta-hydroxycholesterol exposure reduces SPION uptake by cells. Conclusion: SPION loading results in upregulation of lysosomal cathepsin, membranous ferroportin and ferritin degradation, which is associated with secretion of both pro- and anti-inflammatory cytokines. A reduced SPION uptake by oxysterol-laden cells may lead to a compromised MRI with elevated cathepsins and ferritin.

  • 59.
    Laskar, Amit
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Yuan, XiMing
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Li, Wei
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Health Sciences.
    Dimethyl Sulfoxide Prevents 7 beta-Hydroxycholesterol-Induced Apoptosis by Preserving Lysosomes and Mitochondria2010In: JOURNAL OF CARDIOVASCULAR PHARMACOLOGY, ISSN 0160-2446, Vol. 56, no 3, p. 263-267Article in journal (Refereed)
    Abstract [en]

    Dimethyl sulfoxide (DMSO) is a widely used vehicle for water-insoluble substances and exerts a wide range of pharmacologic effects including anti-inflammatory and free radical scavenging properties. Additionally, in an animal model, DMSO inhibited cholesterol- induced atherosclerosis. Despite such profound pharmacologic effects, mechanisms at the cellular level are not well understood. Atherogenic oxysterols, especially 7-oxysterols, are potent inducers of oxidative stress, cell apoptosis, and are elevated in human atherosclerotic lesions. In this study, we first investigated the effect of DMSO on 7 beta-hydroxycholesterol-induced apoptosis of U937 cells and then focused on its influences on production of reactive oxygen species, lysosomal, and mitochondrial membrane permeability. Our results revealed that DMSO protected U937 cells against 7 beta-hydroxycholesterol- induced cell death by preventing lysosomal and mitochondrial membrane permeabilization and reactive oxygen species production. Our results also emphasize the necessity for appropriate solvent control groups in experimental models in which DMSO has been used to examine drug effect or identify pathways.

  • 60.
    Li, Wei
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Ghosh, Moumita
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Eftekhari, Sina
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Yuan, Ximing
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Lipid accumulation and lysosomal pathways contribute to dysfunction and apoptosis of human endothelial cells caused by 7-oxysterols2011In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 409, no 4, p. 711-716Article in journal (Refereed)
    Abstract [en]

    Endothelial dysfunction and cell death play an important role in pathogenesis of atherosclerosis. 7-Oxysterols, the major cytotoxic component found in oxidized low-density lipoprotein, are toxic to endothelial cells. However, the pathways and molecular mechanism involved in the process remain incompletely understood. In this study, we first investigate whether 7 beta-hydroxycholesterol (7 beta OH) or 7-ketocholesterol (7keto) induces apoptosis of human endothelial cell line (HUVEC-CS). We then examine possible involved pathways by focusing on cellular lipid, lysosomal pathways, cellular oxidative stress and mitochondrial pathways. Our results for the first time showed that 7-oxysterols induced apoptotic cell death of HUVEC-CS after 24 h, which was preceded by early lipid accumulation (6 h) and lysosomal membrane permeabilization (6-12 h). Afterward, levels of reactive oxygen species, mitochondrial membrane permeabilization, and lysosomal cathepsin were increased assayed by immuno-cytochemistry and blotting. Notably, the exposure to 7 beta OH or 7keto induced expressions and secretion of isoforms of von Willebrand factor (VWF). We conclude that apoptosis of HUVEC-CS induced by 7 beta OH or 7keto mediates by early lysosomal lipid accumulation and oxidative lysosomal pathways, which results in induction and release of VWF. The results suggest the cell death induced by 7-oxysterols may contribute to endothelial dysfunction and atherothrombosis.

  • 61.
    Li, Wei
    et al.
    Linköping University, Department of Medical and Health Sciences, Pharmacology. Linköping University, Faculty of Health Sciences.
    Johnson, Henrik
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Yuan, Xi-Ming
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Jonasson, Lena
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Health Sciences.
    7beta-hydroxycholesterol induces natural killer cell death via oxidative lysosomal destabilization2009In: Free radical research, ISSN 1071-5762, E-ISSN 1029-2470, Vol. 43, no 11, p. 1072-1079Article in journal (Refereed)
    Abstract [en]

    Peripheral natural killer (NK) cells are reduced in patients with coronary artery disease and highly susceptible to apoptosis induced by oxidized lipids including 7beta-hydroxycholesterol (7betaOH) in vitro. The present study aimed to further explore the mechanisms behind 7betaOH-mediated cytotoxicity to human NK cells. Human NK cells were purified and treated with 7betaOH in different concentrations and times. Cell death, lysosomal and mitochondrial permeabilization and reactive oxygen species (ROS) production were then analysed. The 7betaOH induced time and dose dependent apoptosis and necrosis in human NK cells, which was preceded by loss of lysosomal integrity and enhanced ROS production. At later time points, the mitochondrial membrane permeability in 7betaOH-treated cells was significantly increased. The findings indicate that 7betaOH induces human NK cell death through early lysosomal permeabilization and consequent oxidative stress. The data further suggest that 7betaOH may induce immune disturbances in clinical settings such as atherosclerosis.

  • 62.
    Li, Wei
    et al.
    Linköping University, Department of Medicine and Health Sciences, Clinical Pharmacology . Linköping University, Faculty of Health Sciences.
    Johnson, Henrik
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Yuan, Ximing
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Jonasson, Lena
    Linköping University, Department of Medicine and Health Sciences, Cardiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Cardiology.
    7-beta-hydroxycholesterol induces natural killer cell death via oxidative lysosomal destalization.2009Conference paper (Refereed)
  • 63.
    Li, Wei
    et al.
    Linköping University, Department of Medical and Health Sciences, Pharmacology. Linköping University, Faculty of Health Sciences.
    Johnson, Henrik
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Yuan, Xi-Ming
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Jonasson, Lena
    Linköping University, Department of Medical and Health Sciences, Internal Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Cardiology.
    7ß-hydroxycholesterol induces natural killer cell death via oxidative lysosomal destabilization2009In: Free radical research, ISSN 1071-5762, E-ISSN 1029-2470, Vol. 43, no 11, p. 1072-1079Article in journal (Refereed)
    Abstract [en]

    Peripheral natural killer (NK) cells are reduced in patients with coronary artery disease and highly susceptible to apoptosis induced by oxidized lipids including 7beta-hydroxycholesterol (7betaOH) in vitro. The present study aimed to further explore the mechanisms behind 7betaOH-mediated cytotoxicity to human NK cells. Human NK cells were purified and treated with 7betaOH in different concentrations and times. Cell death, lysosomal and mitochondrial permeabilization and reactive oxygen species (ROS) production were then analysed. The 7betaOH induced time and dose dependent apoptosis and necrosis in human NK cells, which was preceded by loss of lysosomal integrity and enhanced ROS production. At later time points, the mitochondrial membrane permeability in 7betaOH-treated cells was significantly increased. The findings indicate that 7betaOH induces human NK cell death through early lysosomal permeabilization and consequent oxidative stress. The data further suggest that 7betaOH may induce immune disturbances in clinical settings such as atherosclerosis.

  • 64.
    Li, Wei
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Health Sciences.
    Kornmark, Louise
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Jonasson, Lena
    Linköping University, Department of Medical and Health Sciences, Cardiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Cardiology.
    Forssell, Claes
    Linköping University, Department of Medical and Health Sciences, Vascular surgery. Linköping University, Faculty of Health Sciences.
    Yuan, Ximing
    Linköping University, Department of Medical and Health Sciences, Cardiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Cardiology.
    Cathepsin L is significantly associated with apoptosis and plaque destabilization in human atherosclerosis2009In: Atherosclerosis, ISSN 0021-9150, E-ISSN 1879-1484, Vol. 202, no 1, p. 92-102Article in journal (Refereed)
    Abstract [en]

    Objective: Human atherosclerotic lesions overexpress elastolytic and collagenolytic cathepsins with unclear pathological implications. The aim of this study was to investigate the relationship among expression of cathepsin L. macrophage apoptosis in coronary artery disease (CAD) patients, clinical symptoms and plaque severity Of human carotid atheroma.

    Methods and results: Quantitative immunohistochemical analysis of human carotid atherosclerotic lesions (n = 49) showed that expression of lysosomal cathepsin L was significantly increased in atherosclerotic plaques with formation of the necrotic core and rupture of the cap. In those Plaques, cathepsin L was associated mainly with CD68-positive macrophages, whereas significant lower levels of smooth muscle cell actin were detected. The expression of cathepsin L in these plaques was also correlated with apoptosis and the stress protein ferritin. Plaques from symptomatic patients showed greater increased levels of cathepsin L than those front asymptomatic patients. Human monocyte-derived macrophages from CAD patients (n = 7) showed significantly higher levels of cathepsin L, cellular lipids and apoptosis versus cells from matched healthy donors (n = 7). 7Beta-hydroxycholesterol significantly enhanced cathepsin L in cells from healthy donors but not in Cells from CAD patients. Moreover. macrophage apoptosis was significantly correlated with expression of cathepsin L in cell nuclei and membranes.

    Conclusion: The results Suggest that cathepsin L is involved in death of macrophages necrotic Core formation and development of atherosclerotic plaque instability. Macrophage lysosomal cathepsin L and related apoptosis may be potential targets for modulation or imaging of vulnerable plaques in human atherosclerosis.

  • 65.
    Li, Wei
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Laskar, Amit
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Sultana, Nargis
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Osman, Ehab
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Ghosh, Moumita
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Li, Qianqian
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Yuan, Ximing
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Occupational and Environmental Medicine Center.
    Cell death induced by 7-oxysterols via lysosomal and mitochondrial pathways is p53-dependent2012In: Free Radical Biology & Medicine, ISSN 0891-5849, E-ISSN 1873-4596, Vol. 53, no 11, p. 2054-2061Article in journal (Refereed)
    Abstract [en]

    Oxysterol accumulation and p53 expression mainly in macrophages have been associated with cell death and necrotic core formation in human atheroma progression. Oxidative stress and lysosomal membrane permeabilization (LMP) in macrophages are important causes of macrophage apoptosis. However, it is not understood how p53 and oxysterols interact in the process. We show here that 7-oxysterols induce endogenous full-length p53 and phospho-p53 (p53-Ser15) in both nucleus and cytoplasm of THP1 and J774 cells, which is followed by cellular oxidative stress and apoptotic cell death. The role of p53 in 7-oxysterol-mediated cell death is further investigated in temperature sensitive p53-transfected (M1-t-p53) and in p53-deficient (M1) cells. These results reveal that 7-oxysterols induce induction and nuclear translocation of p53 in M1-t-p53 cells, which in turn enhances LMP, mitochondrial translocation of Bax, mitochondrial membrane permeabilization, cytosolic release of cytochrome c, and cell death. Most importantly, the above effects of 7-oxysterols were not observed in p53-deficient M1 cells. The findings reveal that 7-oxysterol-induced cell death occurs via p53-dependent pathways. Subsequent p53 nuclear translocation and induction of wild-type and phosphorylated p53 are early steps in oxysterol-induced lysosomal-mitochondrial pathways involved in cell death.

  • 66.
    Li, Wei
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Health Sciences.
    Lidebjer, Caroline
    Linköping University, Department of Medical and Health Sciences, Cardiology. Linköping University, Faculty of Health Sciences.
    Yuan, Ximing
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology.
    Szymanowski, Aleksander
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medical and Health Sciences, Cardiology. Östergötlands Läns Landsting, Heart Centre, Department of Cardiology.
    Backteman, Karin
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Clinical Immunology. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Immunology and Transfusion Medicine.
    Ernerudh, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Clinical Immunology. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Immunology and Transfusion Medicine.
    Leanderson, Per
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Occupational and Environmental Medicine. Östergötlands Läns Landsting, Pain and Occupational Centre, Occupational and Environmental Medicine Centre.
    Nilsson, Lennart
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Cardiology.
    Swahn, Eva
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medical and Health Sciences, Cardiology. Östergötlands Läns Landsting, Heart Centre, Department of Cardiology.
    Jonasson, Lena
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medical and Health Sciences, Cardiology. Östergötlands Läns Landsting, Heart Centre, Department of Cardiology.
    NK cell apoptosis in coronary artery disease. Relation to oxidative stress2008In: Atherosclerosis, ISSN 0021-9150, E-ISSN 1879-1484, Vol. 199, no 1, p. 65-72Article in journal (Refereed)
    Abstract [en]

    Objective: Natural killer (NK) cells, key elements in initiation and modulation of immune responses, were recently found to be reduced in coronary artery disease (CAD). To clarify mechanisms behind this reduction, we here investigated NK cell apoptosis in CAD patients. Since oxidative stress has been linked to NK cell apoptosis, we related the findings to oxidative stress in vivo and evaluated the ex vivo susceptibility of NK cells to oxidized lipids. Methods and results: The number of apoptotic NK cells in peripheral blood was significantly increased in CAD patients compared to controls. Purified NK cells from CAD patients also showed a higher rate of spontaneous apoptosis ex vivo. Dose- and time-dependent effects of oxidized LDL and 7β-hydroxycholesterol (7βOH) on apoptosis and ROS production were determined in NK cells from blood donors. Thereafter, purified NK cells from CAD patients and healthy controls were exposed to the oxidized lipids in a paired design. NK cells from patients were more susceptible to apoptosis induced by oxidized LDL, in particular 7βOH, compared to cells from controls. Plasma measurements of LDL protein oxidation and lipid peroxidation did not show any differences between patients and controls. On the other hand, plasma carotenoids were significantly decreased in patients and inversely correlated to NK cell apoptosis rate. Conclusion: The rate of spontaneous NK cell apoptosis was increased in CAD patients. Although NK cells in CAD patients were more sensitive to oxidized lipids ex vivo, indicating a mechanism contributing to the reduced NK cell activity in CAD, the data could not verify an obvious link between NK cell apoptosis and increased oxidative stress in vivo. © 2007 Elsevier Ireland Ltd. All rights reserved.

  • 67.
    Li, Wei
    et al.
    Linköping University, Department of Medicine and Health Sciences. Linköping University, Faculty of Health Sciences.
    Miah, S
    Linköping University, Department of Medicine and Health Sciences. Linköping University, Faculty of Health Sciences.
    Jönsson, Simon
    Linköping University, Department of Medicine and Health Sciences. Linköping University, Faculty of Health Sciences.
    Andersson, R
    Linköping University, Department of Medicine and Health Sciences. Linköping University, Faculty of Health Sciences.
    Yuan, Ximing
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    APOPTOSIS INDUCED BY 7B-HYDROXYCHOLESTEROL IS ASSOCIATED WITH REGULATION OF P53, B-CATENIN, AND EGR-1 in ATHEROSCLEROSIS SUPPLEMENTS, vol 10, issue 2, pp2009In: ATHEROSCLEROSIS SUPPLEMENTS, Elsevier Science B.V., Amsterdam. , 2009, Vol. 10, no 2Conference paper (Refereed)
    Abstract [en]

    n/a

  • 68.
    Li, Wei
    et al.
    Linköping University, Department of Medical and Health Sciences. Linköping University, Faculty of Health Sciences.
    Osman, Ehab
    Linköping University, Department of Medical and Health Sciences. Linköping University, Faculty of Health Sciences.
    Forssell, C
    Linköping University, Department of Medical and Health Sciences. Linköping University, Faculty of Health Sciences.
    Yuan, Ximing
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    THROMBIN RECEPTOR (PAR1), TISSUE FACTOR AND IRON BINDING PROTEINS IN HUMAN CAROTID ATHEROSCLEROSIS2009In: ATHEROSCLEROSIS SUPPLEMENTS, Elsevier, 2009, Vol. 10, no 2, p. e595-e595Conference paper (Other academic)
  • 69.
    Li, Wei
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Health Sciences.
    Xu, Lihua
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology.
    Forssell, C.
    Sullivan, J.L.
    Burnett College of Biomedical Sciences, University of Central Florida, Orlando, FL 32816.
    Yuan, Ximing
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine.
    Overexpression of transferrin receptor and ferritin related to clinical symptoms and destabilization of human carotid plaques2008In: Experimental biology and medicine (Maywood, N.J.: Print), ISSN 1535-3702, E-ISSN 1535-3699, Vol. 233, no 7, p. 818-826Article in journal (Refereed)
    Abstract [en]

    Accumulation of tissue iron has been implicated in development of atherosclerotic lesions mainly because of increased iron-catalyzed oxidative injury. However, it remains unknown whether cellular iron import and storage in human atheroma are related to human atheroma development. We found that transferrin receptor 1 (TfR1), a major iron importer, is highly expressed in foamy macrophages and some smooth muscle cells in intimal lesions of human carotid atheroma, mainly in cytoplasmic accumulation patterns. In 52 human carotid atherosclerotic lesions, TfR1 expression was positively correlated with macrophage infiltration, ectopic lysosomal cathepsin L, and ferritin expression. Highly expressed TfR1 and ferritin in CD68-positive macrophages were significantly associated with development and severity of human carotid plaques, smoking, and patient's symptoms. The findings suggest that pathologic macrophage iron metabolism may contribute to vulnerability of human atheroma, established risk factors, and their clinical symptoms. The cytoplasmic overexpression of TfR1 may be the result of lysosomal dysfunction and ectopic accumulation of lysosomal cathepsin I caused by atheroma-relevant lipids in atherogenesis. Copyright © 2008 by the Society for Experimental Biology and Medicine.

  • 70.
    Li, Wei
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences.
    Xu, Lihua
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology .
    Yuan, Ximing
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine.
    Macrophage hemoglobin scavenger receptor and ferritin accumulation in human atherosclerotic lesions2004In: Annals of the New York Academy of Sciences, ISSN 0077-8923, E-ISSN 1749-6632, Vol. 1030, p. 196-201Article in journal (Refereed)
    Abstract [en]

    We previously proposed that erythrophagocytosis and iron metabolism by macrophages may contribute to iron-driven oxidative stress in atherogenesis. Recent studies have indicated that the macrophage hemoglobin scavenger receptor (HbSR/CD 163) is a key molecule in the process of removing hemoglobin released from senescent erythrocytes. In this study we investigated crythrophagocytosis and its relation to ferritin accumulation and the involvement of CD163 in ferritin induction in human atheroma lesions. Normal and atherosclerotic human arterial segments obtained at autopsy and surgery were collected for iron histochemistry, hemoglobin and ferritin immunohistochemistry, and computerized image analysis. The lesion-dependent accumulation of ferritin and hemoglobin was seen in atherosclerotic carotid and coronary arteries. The immunoreactivity of hemoglobin was significantly correlated to the same regions of ferritin immunoreactivity on serial sections. The staining intensity of hemoglobin and ferritin was also significantly correlated. Hemoglobin deposition is often associated with microvessels adjacent to the lipid core areas in advanced lesions, where most CD68-positive macrophages were. CD163 expression appeared in both early and advanced lesions. The accumulation of tissue iron and ferritin also frequently occurs in CD163-positive and vessel-rich regions in the advanced atheroma. Although they were not always correspondingly positive on the serial sections, tissue iron and ferritin were significantly correlated. We conclude that erythrophagocytosis and hemoglobin catabolism by macrophages contribute to iron deposition and ferritin induction in human atheroma. The involvement of CD163 during ferritin induction may play an important role in modulating inflammatory processes in atherogenesis.

  • 71.
    Li, Wei
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences.
    Yuan, Ximing
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine.
    Ivanova, S.
    Laboratory of Biomedical Science, North Shore-LIE Research Institute, Manhasset, NY 11030, United States.
    Tracey, K.J.
    Laboratory of Biomedical Science, North Shore-LIE Research Institute, Manhasset, NY 11030, United States.
    Eaton, John Wallace
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Brunk, Ulf
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Pharmacology .
    3-Aminopropanal, formed during cerebral ischaemia, is a potent lysosomotropic neurotoxin2003In: Biochemical Journal, ISSN 0264-6021, E-ISSN 1470-8728, Vol. 371, no 2, p. 429-436Article in journal (Refereed)
    Abstract [en]

    Cytotoxic polyamine-derived amino aldehydes, formed during cerebral ischaemia, damage adjacent tissue (the so-called 'penumbra') not subject to the initial ischaemic insult. One such product is 3-aminopropanal (3-AP), a potent cytotoxin that accumulates in ischaemic brain, although the precise mechanisms responsible for its formation are still unclear. More relevant to the present investigations, the mechanisms by which such a small aldehydic compound might be cytotoxic are also not known, but we hypothesized that 3-AP, having the structure of a weak lysosomotropic base, might concentrate within lysosomes, making these organelles a probable focus of initial toxicity. Indeed, 3-AP leads to lysosomal rupture of D384 glioma cells, a process which clearly precedes caspase activation and apoptotic cell death. Immunohistochemistry reveals that 3-AP concentrates in the lysosomal compartment and prevention of this accumulation by the lysosomotropic base ammonia, NH3, protects against 3-AP cytotoxicity by increasing lysosomal pH. A thiol compound, N-(2-mercaptopropionyl)glycine, reacts with and neutralizes 3-AP and significantly inhibits cytoxocity. Both amino and aldehyde functions of 3-AP are necessary for toxicity: the amino group confers lysosomotropism and the aldehyde is important for additional, presently unknown, reactions. We conclude that 3-AP exerts its toxic effects by accumulating intralysosomally, causing rupture of these organelles and releasing lysosomal enzymes which initiate caspase activation and apoptosis (or necrosis if the lysosomal rupture is extensive). These results may have implications for the development of new therapeutics designed to lessen secondary damage arising from focal cerebral ischaemia.

  • 72.
    Li, Wei
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences.
    Östblom, Mattias
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics .
    Xu, Lihua
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology .
    Hellsten, A.
    Leanderson, Per
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Occupational and Environmental Medicine . Östergötlands Läns Landsting, Centre for Medicine, Pain and Rehabilitation Centre.
    Liedberg, Bo
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics .
    Brunk, Ulf
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Pharmacology .
    Eaton, J.W.
    James Graham Brown Cancer Center, University of Louisville, Louisville, KY, United States.
    Yuan, Ximing
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine.
    Cytocidal effects of atheromatous plaque components: The death zone revisited2006In: The FASEB Journal, ISSN 0892-6638, E-ISSN 1530-6860, Vol. 20, no 13, p. 2281-2290Article in journal (Refereed)
    Abstract [en]

    Objective: Earlier we suggested that atheroma lesions constitute a "death zone" containing toxic materials that may cause dysfunction and demise of invading macrophages to prevent the removal of plaque materials. Here we have assessed the cytotoxic effects of nonfractionated gruel and insoluble (ceroid-like) material derived from advanced human atheroma. Methods and Results: The insoluble material within advanced atherosclerotic plaque was isolated following protease K digestion and extensive extraction with aqueous and organic solvents. FTIR, Raman, and atomic absorption spectroscopy suggested that, despite its fluorescent nature, this material closely resembled hydroxyapatite and dentin, but also contained a significant amount of iron and calcium. When added to J774 cells and human macrophages in culture, this insoluble substance was phagocytosed, and progressive cell death followed. However, an even more cytotoxic activity was found in the atheromatous "gruel" that contains abundant carbonyls/aldehydes. Cell death caused by both crude gruel and ceroid could be blocked by preincubating cells with the lipophilic iron chelator salicylaldehyde isonicotinoyl hydrazone, apoferritin, BAPTA/AM, or sodium borohydride, indicating that cellular iron, calcium, and reactive aldehyde(s) are responsible for the observed cytotoxicity. Conclusions: Toxic materials within atheromatous lesions include both ceroid and even more cytotoxic lipidaceous materials. The cytotoxic effects of these plaque components may help explain the persistence of atherosclerotic lesions. © FASEB.

  • 73.
    Liu, Yawei
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Effects of pH on platelets release of growth factors in wound healing2003Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Wound healing is thought to involve a complex series of interactions between biochemical mediators, cells and extracellular matrix. Known to stimulate cellular movement, proliferation and biosynthetic activity, growth factors may play a significant role in stimulating wound repair. This thesis focuses on the early phase of wound healing. We established an experimental model which mimics the early proliferative stage and concentrated on a potentially interesting aspect of the wound environment pH as a modulator of the release of growth factors from platelets. The influence of platelet-rich plasma lysates on fibroblast proliferation at varying pH was studied in culture. We found that the concentration of platelet-derived growth factor in the different lysates was highest at pH 5.0. The concentration of transforming growth factor beta, however, was lower after incubation at pH 5.0 than at pH 7.1 and 7.6. Fibroblast proliferation and collagen production were enhanced by platelet lysates at pH 5.0, 7.1 and 7.6.We also studied the release of growth factors from platelet supernatants which were thrombin-activated at pH 7.4, then the pH was lowered to 5.0, remained the same or was raised to 8.5, or were thrombin-activated (or not) at pH 5.0, 7.4 and 8.5. Our results suggest that release of growth factors is dependent not only on platelet activation, but also on long-term incubation at 37°C and change in pH. ln summary, we found that pH may influence the activity of platelet proteins, resulting in fibroblast growth and promotion of wound healing.

    List of papers
    1. Fibroblast proliferation due to exposure to a platelet concentrate in vitro is pH dependent
    Open this publication in new window or tab >>Fibroblast proliferation due to exposure to a platelet concentrate in vitro is pH dependent
    2002 (English)In: Wound Repair and Regeneration, ISSN 1067-1927, E-ISSN 1524-475X, Vol. 10, no 5, p. 336-340Article in journal (Refereed) Published
    Abstract [en]

    The influence of platelet-rich plasma lysates on fibroblast proliferation was studied in culture. Cells were exposed to platelet lysates that had been preincubated at different pHs (5.0, 7.1, and 7.6). Proliferation was evaluated with the MTT assay and incorporation of [3H]thymidine into macromolecules, while type I collagen production was assayed by Western blotting. Enzyme-linked immunosorbent assays were used to determine platelet-derived growth factor and transforming growth factor-β concentrations. Platelets preincubated in an acidic environment (pH 5.0) induced the highest degree of fibroblast proliferation, and the concentration of platelet-derived growth factor in the different treated lysates was the highest at that particular pH. The concentration of transforming growth factor-β, however, was lower after incubation at pH 5.0 than at either pH 7.1 or 7.6. These findings may be relevant to normal wound healing in vivo and useful in the treatment of wounds and delayed healing processes.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-27830 (URN)10.1046/j.1524-475X.2002.10510.x (DOI)000178921600010 ()12587 (Local ID)12587 (Archive number)12587 (OAI)
    Available from: 2009-10-08 Created: 2009-10-08 Last updated: 2017-12-13
    2. Time- and pH-dependent release of PDGF and TGF-ß from platelets in vitro
    Open this publication in new window or tab >>Time- and pH-dependent release of PDGF and TGF-ß from platelets in vitro
    2003 (English)In: Platelets, ISSN 0953-7104, E-ISSN 1369-1635, Vol. 14, no 4, p. 233-237Article in journal (Refereed) Published
    Abstract [en]

    We studied the spontaneous and thrombin-induced activation of platelets and their release of platelet-derived growth factor (PDGF) and transforming growth factor-β (TGF-β) at different pH values. Platelet activation was assayed with anti-bodies against P-selectin and performed in serum-free media. The release of PDGF and TGF-β was determined by ELISA after 15 min and 12 h. There was no activation at pH 5.0, while a time-dependent release of growth factors occurred at neutral and alkaline pH. The results suggest that release of growth factors is not only dependent on platelet activation but also on incubation time and pH. Although the used serum-free experimental situation is different from normal conditions for platelets in vivo, the findings of a late release of growth factors may, nevertheless, be relevant to wound healing.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-27831 (URN)10.1080/0953710031000118876 (DOI)000183567300005 ()12588 (Local ID)12588 (Archive number)12588 (OAI)
    Available from: 2009-10-08 Created: 2009-10-08 Last updated: 2017-12-13
  • 74.
    Liu, Yawei
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Kalén, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Orthopaedics in Linköping.
    Risto, Olof
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics. Linköping University, Faculty of Health Sciences.
    Wahlström, Ola
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics. Linköping University, Faculty of Health Sciences.
    Fibroblast proliferation due to exposure to a platelet concentrate in vitro is pH dependent2002In: Wound Repair and Regeneration, ISSN 1067-1927, E-ISSN 1524-475X, Vol. 10, no 5, p. 336-340Article in journal (Refereed)
    Abstract [en]

    The influence of platelet-rich plasma lysates on fibroblast proliferation was studied in culture. Cells were exposed to platelet lysates that had been preincubated at different pHs (5.0, 7.1, and 7.6). Proliferation was evaluated with the MTT assay and incorporation of [3H]thymidine into macromolecules, while type I collagen production was assayed by Western blotting. Enzyme-linked immunosorbent assays were used to determine platelet-derived growth factor and transforming growth factor-β concentrations. Platelets preincubated in an acidic environment (pH 5.0) induced the highest degree of fibroblast proliferation, and the concentration of platelet-derived growth factor in the different treated lysates was the highest at that particular pH. The concentration of transforming growth factor-β, however, was lower after incubation at pH 5.0 than at either pH 7.1 or 7.6. These findings may be relevant to normal wound healing in vivo and useful in the treatment of wounds and delayed healing processes.

  • 75.
    Liu, Yawei
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Kalén, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics. Linköping University, Faculty of Health Sciences.
    Risto, Olof
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics. Linköping University, Faculty of Health Sciences.
    Wahlström, Ola
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics. Linköping University, Faculty of Health Sciences.
    Time- and pH-dependent release of PDGF and TGF-ß from platelets in vitro2003In: Platelets, ISSN 0953-7104, E-ISSN 1369-1635, Vol. 14, no 4, p. 233-237Article in journal (Refereed)
    Abstract [en]

    We studied the spontaneous and thrombin-induced activation of platelets and their release of platelet-derived growth factor (PDGF) and transforming growth factor-β (TGF-β) at different pH values. Platelet activation was assayed with anti-bodies against P-selectin and performed in serum-free media. The release of PDGF and TGF-β was determined by ELISA after 15 min and 12 h. There was no activation at pH 5.0, while a time-dependent release of growth factors occurred at neutral and alkaline pH. The results suggest that release of growth factors is not only dependent on platelet activation but also on incubation time and pH. Although the used serum-free experimental situation is different from normal conditions for platelets in vivo, the findings of a late release of growth factors may, nevertheless, be relevant to wound healing.

  • 76.
    Lundqvist, Helen
    et al.
    Department of Molecular and Clinical Medicine Linköping University.
    Dånmark, Staffan
    Department of Neuroscience and Locomotion Linköping University.
    Johansson, Uno
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology .
    Gustafsson, Håkan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Radiation Physics .
    Öllinger, Karin
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Evaluation of electron spin resonance for studies of superoxide anion production by human neutrophils interacting with Staphylococcus aureus and Staphylococcus epidermidis.2008In: Journal of Biochemical and Biophysical Methods, ISSN 0165-022X, E-ISSN 1872-857X, Vol. 70, no 6, p. 1059-1065Article in journal (Refereed)
    Abstract [en]

    The present study evaluates electron spin resonance (ESR) and the spin trapper 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide (DEPMPO) for analysis of superoxide radical production by human neutrophils interacting with viable Staphylococcus aureus and Staphylococcus epidermidis bacteria. To avoid auto-activation due to interaction with glass surfaces, neutrophils were preincubated in plastic tubes until the peak response was reached, and then transferred to a quartz flat cell to record the ESR spectra. The time point for peak response was identified by parallel analysis of the bacteria-neutrophil interaction using luminol amplified chemiluminescence. We found detectable ESR spectra from neutrophils interacting with as few as five bacteria of the weak activating S. epidermidis per neutrophil. Addition of the NADPH oxidase inhibitor diphenylene iodonium totally abolished spectra. Catalase, DMSO or an iron chelator had no impact on the produced spectra and ionomycin, a selective activator of intracellular NADPH oxidase, gave significant ESR spectra. Taken together, our results indicate that DEPMPO is cell permeable and detects NADPH oxidase derived superoxide anions formed in phagosomes or released by human neutrophils phagocytosing viable S. aureus and S. epidermidis. The technique may be used as a sensitive tool to evaluate superoxide anion production in human neutrophils.

  • 77.
    Miah, Sayem
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Zadeh, Shahram Nour Mohammad
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Yuan, Xi-Ming
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Occupational and Environmental Medicine Center.
    Li, Wei
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Expression of Egr1 and p53 in human carotid plaques and apoptosis induced by 7-oxysterol or p53.2013In: Experimental and Toxicological Pathology, ISSN 0940-2993, E-ISSN 1618-1433, Vol. 65, no 5, p. 677-682Article in journal (Refereed)
    Abstract [en]

    Egr-1 and p53 are involved in pathology of both atherosclerosis and cancer. However, it is unknown whether p53 and Egr1 are interactively involved in apoptosis in atherosclerosis. We found that in human carotid plaques, the expression of p53 was inversely correlated with Egr1. In U937 cells, 7 beta-hydroxycholesterol and 7-ketocholesterol induced production of reactive oxygen species (ROS), transient up-regulation of Egr1 followed by late induction of p53 and apoptosis. Cells with nuclear fragmentation induced by 7-oxysterol or p53 showed increased levels of p53, but decreased levels of Egr1. In conclusion, ROS induced by 7-oxysterols may function as an early initiator of Egr1 expression. The late induced p53 by 7-oxysterols contributes to apoptotic cell death and is linked to the reduction of Egr1 levels, which resembles the differential expression of p53 and Egr1 in human atheroma progression.

  • 78.
    Nath, Sangeeta
    et al.
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Agholme, Lotta
    Linköping University, Department of Clinical and Experimental Medicine, Geriatric. Linköping University, Faculty of Health Sciences.
    Roshan, Firoz
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Granseth, Björn
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Marcusson, Jan
    Linköping University, Department of Clinical and Experimental Medicine, Geriatric. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in Central Östergötland, Department of Geriatric Medicine.
    Hallbeck, Martin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Spreading of Neurodegenerative Pathology via Neuron-to-Neuron Transmission of beta-Amyloid2012In: Journal of Neuroscience, ISSN 0270-6474, E-ISSN 1529-2401, Vol. 32, no 26, p. 8767-8777Article in journal (Refereed)
    Abstract [en]

    Alzheimers disease (AD) is the major cause of dementia. During the development of AD, neurofibrillary tangles progress in a fixed pattern, starting in the transentorhinal cortex followed by the hippocampus and cortical areas. In contrast, the deposition of beta-amyloid (A beta) plaques, which are the other histological hallmark of AD, does not follow the same strict spatiotemporal pattern, and it correlates poorly with cognitive decline. Instead, soluble A beta oligomers have received increasing attention as probable inducers of pathogenesis. In this study, we use microinjections into electrophysiologically defined primary hippocampal rat neurons to demonstrate the direct neuron-to-neuron transfer of soluble oligomeric A beta. Additional studies conducted in a human donor-acceptor cell model show that this A beta transfer depends on direct cellular connections. As the transferred oligomers accumulate, acceptor cells gradually show beading of tubulin, a sign of neurite damage, and gradual endosomal leakage, a sign of cytotoxicity. These observations support that intracellular A beta oligomers play a role in neurodegeneration, and they explain the manner in which A beta can drive disease progression, even if the extracellular plaque load is poorly correlated with the degree of cognitive decline. Understanding this phenomenon sheds light on the pathophysiological mechanism of AD progression. Additional elucidation will help uncover the detailed mechanisms responsible for the manner in which AD progresses via anatomical connections and will facilitate the development of new strategies for stopping the progression of this incapacitating disease.

  • 79.
    Neuzil, J.
    et al.
    Institute for Prevention of Cardiovascular Diseases and Medical Policlinic, Ludwig-Maximilians-University, Munich, Germany, Institute for Prevention of Cardiovascular Diseases, Pettenkoferstrasse 9, 80336 Munich, Germany.
    Weber, T.
    Institute for Prevention of Cardiovascular Diseases and Medical Policlinic, Ludwig-Maximilians-University, Munich, Germany.
    Schroder, A.
    Schröder, A., Institute for Prevention of Cardiovascular Diseases and Medical Policlinic, Ludwig-Maximilians-University, Munich, Germany.
    Lu, M.
    Medical Center North, Vanderbilt University, Nashville, TN, United States.
    Ostermann, G.
    Institute for Prevention of Cardiovascular Diseases and Medical Policlinic, Ludwig-Maximilians-University, Munich, Germany.
    Gellert, N.
    Institute for Prevention of Cardiovascular Diseases and Medical Policlinic, Ludwig-Maximilians-University, Munich, Germany.
    Mayne, G.C.
    Flinders University of South Australia, Adelaide, SA, Australia.
    Olejnicka, Beata
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology .
    Negre-Salvayre, A.
    Nègre-Salvayre, A., Biochemistry Department, INSERM, Toulouse, France.
    Sticha, M.
    Stícha, M., Faculty of Science, Charles University, Prague, Czech Republic.
    Coffey, R.J.
    Medical Center North, Vanderbilt University, Nashville, TN, United States.
    Weber, C.
    Institute for Prevention of Cardiovascular Diseases and Medical Policlinic, Ludwig-Maximilians-University, Munich, Germany, Institute for Prevention of Cardiovascular Diseases, Pettenkoferstrasse 9, 80336 Munich, Germany.
    Induction of cancer cell apoptosis by a-tocopheryl succinate: Molecular pathways and structural requirements2001In: The FASEB Journal, ISSN 0892-6638, E-ISSN 1530-6860, Vol. 15, no 2, p. 403-415Article in journal (Refereed)
    Abstract [en]

    The vitamin E analog a-tocopheryl succinate (a-TOS) can induce apoptosis. We show that the proapoptotic activity of a-TOS in hematopoietic and cancer cell lines involves inhibition of protein kinase C (PKC), since phorbol myristyl acetate prevented a-TOS-triggered apoptosis. More selective effectors indicated that a-TOS reduced PKCa isotype activity by increasing protein phosphatase 2A (PP2A) activity. The role of PKCa inhibition in a-TOS-induced apoptosis was confirmed using antisense oligonucleotides or PKCa overexpression. Gain- or loss-of-function bcl-2 mutants implied modulation of bcl-2 activity by PKC/PP2A as a mitochondrial target of a-TOS-induced proapoptotic signals. Structural analogs revealed that a-tocopheryl and succinyl moieties are both required for maximizing these effects. In mice with colon cancer xenografts, a-TOS suppressed tumor growth by 80%. This epitomizes cancer cell killing by a pharmacologically relevant compound without known side effects.

  • 80.
    Neuzil, J.
    et al.
    Apoptosis Research Group, Heart Foundation Research Centre, Griffith University, Gold Coast Campus, Southport, QLD 9716, Australia, Molecular Therapy Group, Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic.
    Widen, C.
    Widén, C., Apoptosis Research Group, Heart Foundation Research Centre, Griffith University, Gold Coast Campus, Southport, QLD 9716, Australia.
    Gellert, N.
    Apoptosis Research Group, Heart Foundation Research Centre, Griffith University, Gold Coast Campus, Southport, QLD 9716, Australia.
    Swettenham, E.
    Apoptosis Research Group, Heart Foundation Research Centre, Griffith University, Gold Coast Campus, Southport, QLD 9716, Australia.
    Zobalova, R.
    Apoptosis Research Group, Heart Foundation Research Centre, Griffith University, Gold Coast Campus, Southport, QLD 9716, Australia, Molecular Therapy Group, Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic.
    Dong, L.-F.
    Apoptosis Research Group, Heart Foundation Research Centre, Griffith University, Gold Coast Campus, Southport, QLD 9716, Australia.
    Wang, X.-F.
    Apoptosis Research Group, Heart Foundation Research Centre, Griffith University, Gold Coast Campus, Southport, QLD 9716, Australia.
    Lidebjer, C.
    Apoptosis Research Group, Heart Foundation Research Centre, Griffith University, Gold Coast Campus, Southport, QLD 9716, Australia.
    Dalen, Helge
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology .
    Headrick, J.P.
    Apoptosis Research Group, Heart Foundation Research Centre, Griffith University, Gold Coast Campus, Southport, QLD 9716, Australia.
    Witting, P.K.
    ANZAC Research Institute, Concord Repatriation Hospital, University of Sydney, Concord, NSW, Australia.
    Mitochondria transmit apoptosis signalling in cardiomyocyte-like cells and isolated hearts exposed to experimental ischemia-reperfusion injury2007In: Redox report, ISSN 1351-0002, E-ISSN 1743-2928, Vol. 12, no 3, p. 148-162Article in journal (Refereed)
    Abstract [en]

    Ischemia-reperfusion (I/R) is a condition leading to serious complications due to death of cardiac myocytes. We used the cardiomyocyte-like cell line H9c2 to study the mechanism underlying cell damage. Exposure of the cells to simulated I/R lead to their apoptosis. Over-expression of Bcl-2 and Bcl-xL protected the cells from apoptosis while over-expression of Bax sensitized them to programmed cell death induction. Mitochondria-targeted coenzyme Q (mitoQ) and superoxide dismutase both inhibited accumulation of reactive oxygen species (ROS) and apoptosis induction. Notably, mtDNA-deficient cells responded to I/R by decreased ROS generation and apoptosis. Using both in situ and in vivo approaches, it was found that apoptosis occurred during reperfusion following ischemia, and recovery was enhanced when hearts from mice were supplemented with mitoQ. In conclusion, I/R results in apoptosis in cultured cardiac myocytes and heart tissue largely via generation of mitochondria-derived superoxide, with ensuing apoptosis during the reperfusion phase. © W. S. Maney & Son Ltd.

  • 81.
    Nielsen, JB
    et al.
    Univ So Denmark, DK-5000 Odense C, Denmark Linkoping Univ, Linkoping, Sweden.
    Hultman, Per
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Mercury-induced autoimmunity in mice2002In: Journal of Environmental Health Perspectives, ISSN 0091-6765, E-ISSN 1552-9924, Vol. 110, p. 877-881Article in journal (Refereed)
    Abstract [en]

    We have studied the effect of gender, genetics, and toxicokinetics on immune parameters in mercury-induced autoimmunity in mice. Data strongly suggest that the mechanism for mercury-induced autoimmunity involves modification of the autoantigen fibrillarin by mercury followed by a T-cell-dependent immune response driven by the modified fibrillarin. Mice with different H-2 haplotypes were treated with (HgCl2)-Hg-203 in a dose of 0.5-16 mg Hg/L drinking water for 10 weeks. Whole-body accumulation and renal accumulation of mercury were assessed. Serum antinuclear antibodies were used to evaluate the autoimmune response, and serum immunoglobulin E (IgE) to study effects on T-helper cells of type 2. Strains with a susceptible H-2 haplotype developed autoantibodies to the nucleolar protein fibrillarin (AFA) in a dose-dependent pattern within 2 weeks. The substantially lower whole-body and organ mercury level needed to induce AFA in the susceptible A.SW strain compared with the H-2 congenic B10.S strain demonstrates that genetic factors outside the H-2 region modify the autoimmune response. Mouse strains without the susceptible haplotype did not develop any autoimmune reaction irrespective of dose and organ deposition of mercury. In susceptible mouse strains, males and females had different thresholds for induction of autoimmune reactions. In susceptible strains, serum IgE increased dose dependently and reached a maximum after 1-2.5 weeks. A susceptible H-2 haplotype is therefore a prerequisite for the autoimmune response. Mercury exposure will modulate the response, qualitatively through the existence of dose-related thresholds for autoimmune response and quantitatively as increasing doses cause increasing autoimmune response. Further, gender and non-H-2 genes modulate both the induction and subsequent development of AFA. Induction of IgE seems not to be mechanistically linked to the AFA response.

  • 82. Order onlineBuy this publication >>
    Nilsson, Cathrine
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Impact of Lysosomal Function in Cancer and Apoptosis2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Lysosomes, the recycling units of the cell, participate in the signaling pathway to apoptosis, which has stimulated the search for anti-cancer drugs targeting the lysosomal compartment. Lysosomes are, however, often altered in cancer cells. The aim of this thesis was to investigate the involvement of lysosomes during apoptosis in normal and cancer cells. We developed and used flow cytometric methods to measure cytosolic and lysosomal pH in cells. The cytosolic pH of U937 cells decreased, in a caspase-independent way, by 1.4 pH-units during apoptosis. Concomitantly, the lysosomal pH increased from 4.3 to 5.2, suggesting that proton release from lysosomes might be responsible for cytosolic acidification. When studying the lysosomal pH of head and neck squamous cell carcinoma (HNSCC) cell lines and normal oral keratinocytes (NOKs), the pH was significantly increased in three of five HNSCC cell lines, as compared to NOKs. Moreover, high lysosomal pH correlated to low expression of the B subunit of the vacuolar V0/V1-ATPase, a necessary component of the proton pump responsible for lysosomal acidification, and to reduced intrinsic cisplatin sensitivity. Cisplatin-induced apoptosis was, at least partly, dependent on lysosomal cathepsins. When investigating the colony formation ability of the two HNSCC cell lines LK0412 and SqCC/Y1, both were found to give rise to holoclones, indicating the presence of cells with cancer stem cell properties. Holoclone cells from the LK0412 cell line were less sensitive to cisplatin compared to more differentiated paraclone cells. Moreover, we detected differences in intracellular localization of the lysosomal compartment and expression of cathepsins between holo- and paraclone cells.

    This thesis shows that changes found in the lysosomal compartment of cancer cells, such as alteration of lysosomal pH, might influence the outcome of a drug treatment. In addition, differences in drug sensitivity between subpopulations of tumor cells may affect the outcome of an anticancer therapy.

    List of papers
    1. Analysis of cytosolic and lysosomal pH in apoptotic cells by flow cytometry
    Open this publication in new window or tab >>Analysis of cytosolic and lysosomal pH in apoptotic cells by flow cytometry
    2004 (English)In: Methods in Cell Science, ISSN 1381-5741, Vol. 25, no 3-4, p. 185-194Article in journal (Refereed) Published
    Abstract [en]

    Several reports indicate that the cytosol is acidified during apoptosis although the mechanism is not yet fully elucidated. The most acidic organelle found in the cell is the lysosome, raising the possibility that lysosomal proton release may contribute to the cytosolic acidification. We here describe methods for measurement of the cytosolic and lysosomal pH in U937 cells by a dual-emission ratiometric technique suitable for flow cytometry. Cytosolic pH was analysed in cells loaded with the fluorescent probe BCECF, while lysosomal pH was determined after endocytosis of FITC-dextran. Standard curves were obtained by incubating cells in buffers with different pH in the presence of the proton ionophore nigericin. Apoptosis was induced by exposure of cells to 10ng/ml TNF- for 4h, and apoptotic cells were identified using a fluorescent marker for active caspases. By gating of control and apoptotic cells, the cytosolic and lysosomal pH were calculated in each population. The cytosolic pH was found to decrease from 7.2 ± 0.1 to 5.8s±0.1 and the lysosomal increased from 4.3±0.4 to 5.2±0.3. These methods will be useful in future attempts to evaluate the involvement of lysosomes in the acidification of the cytosol during apoptosis.

    Keywords
    Apoptosis, Flow cytometry, Lysosomes, pH measurement
    National Category
    Cell and Molecular Biology
    Identifiers
    urn:nbn:se:liu:diva-15134 (URN)10.1007/s11022-004-8228-3 (DOI)
    Available from: 2008-10-17 Created: 2008-10-17 Last updated: 2018-01-12Bibliographically approved
    2. Cytosolic acidification and lysosomal alkalinization during TNF-α induced apoptosis in U937 cells
    Open this publication in new window or tab >>Cytosolic acidification and lysosomal alkalinization during TNF-α induced apoptosis in U937 cells
    Show others...
    2006 (English)In: Apoptosis (London), ISSN 1360-8185, E-ISSN 1573-675X, Vol. 11, no 7, p. 1149-1159Article in journal (Refereed) Published
    Abstract [en]

    Apoptosis is often associated with acidification of the cytosol and since loss of lysosomal proton gradient and release of lysosomal content are early events during apoptosis, we investigated if the lysosomal compartment could contribute to cytosolic acidification. After exposure of U937 cells to tumor necrosis factor-α, three populations; healthy, pre-apoptotic, and apoptotic cells, were identified by flow cytometry. These populations were investigated regarding intra-cellular pH and apoptosis-associated events. There was a drop in cytosolic pH from 7.2 ± 0.1 in healthy cells to 6.8 ± 0.1 in pre-apoptotic, caspase-negative cells. In apoptotic, caspase-positive cells, the pH was further decreased to 5.7 ± 0.04. The cytosolic acidification was not affected by addition of specific inhibitors towards caspases or the mitochondrial F0F1-ATPase. In parallel to the cytosolic acidification, a rise in lysosomal pH from 4.3 ± 0.3, in the healthy population, to 4.8 ± 0.3 and 5.5 ± 0.3 in the pre-apoptotic- and apoptotic populations, respectively, was detected. In addition, lysosomal membrane permeability increased as detected as release of cathepsin D from lysosomes to the cytosol in pre-apoptotic and apoptotic cells. We, thus, suggest that lysosomal proton release is the cause of the cytosolic acidification of U937 cells exposed to TNF-α.

    Place, publisher, year, edition, pages
    Springer Netherlands, 2006
    Keywords
    Apoptosis, Cathepsin, Cytosolic acidification, Lysosomal alkalinization, pH, TNF-α
    National Category
    Cell Biology
    Identifiers
    urn:nbn:se:liu:diva-15135 (URN)10.1007/s10495-006-7108-5 (DOI)
    Available from: 2008-10-17 Created: 2008-10-17 Last updated: 2018-10-08Bibliographically approved
    3. Intrinsic differences in cisplatin sensitivity of head and neck cancer celllines correlates to lysosomal pH
    Open this publication in new window or tab >>Intrinsic differences in cisplatin sensitivity of head and neck cancer celllines correlates to lysosomal pH
    2010 (English)In: Head and Neck, ISSN 1043-3074, E-ISSN 1097-0347, Vol. 32, no 9, p. 1185-1194Article in journal (Refereed) Published
    Abstract [en]

    Cisplatin is part of the treatment regime of head and neck squamous cell carcinomas (HNSCC). In order to predict the clinical outcome of the treatment, markers for evaluation of the intrinsic cisplatin sensitivity are inquired. In this study we characterize the lysosomal compartment and compare cisplatin sensitivity in five HNSCC lines and normal oral keratinocytes (NOKs). Cisplatin sensitivity differed 3-fold between the least and most sensitive cell lines, and the cisplatin LD50 correlated significantly to lysosomal pH, which varied from 4.3 in NOKs to 4.9 in the most resistant HNSCC line. Lysosomes are acidified by the V0V1-ATPase complex located in the lysosomal membrane. Interestingly, in cell lines exhibiting high lysosomal pH, we found decreased expression of the V0V1-ATPase B2 subunit, possibly explaining the defective acidification. In all cell lines, exposure to cisplatin caused activation of caspase-3. Cisplatin exposure was accompanied by lysosomal membrane permeabilization and inhibition of the llysosomal cathepsins B, D and L partly prevented cell death. No correlation between cisplatin sensitivity and expression of cathepsins B, D and L or secretion of their respective proforms into the culture medium was found in the cell lines studied. We conclude that lysosomal pH and expression of V0V1-ATPase subunits are possible future markers of intrinsic cisplatin sensitivity.

    Place, publisher, year, edition, pages
    John Wiley & Sons, 2010
    Keywords
    apoptosis, cathepsin, chemotherapy resistance, lysosome, V0V1-ATPase
    National Category
    Cell and Molecular Biology
    Identifiers
    urn:nbn:se:liu:diva-15136 (URN)10.1002/hed.21317 (DOI)000281528100008 ()
    Note

    The previous status of this article was Manuscript and the working title was Radiation and cisplatin sensitivity in head and neck cancer cells with stem cell properties.

    Available from: 2008-10-17 Created: 2008-10-17 Last updated: 2018-02-12Bibliographically approved
    4. Intrinsic differences in cisplatin sensitivity of head and neck cancer celllines correlates to lysosomal pH
    Open this publication in new window or tab >>Intrinsic differences in cisplatin sensitivity of head and neck cancer celllines correlates to lysosomal pH
    2010 (English)In: Head and Neck, ISSN 1043-3074, E-ISSN 1097-0347, Vol. 32, no 9, p. 1185-1194Article in journal (Refereed) Published
    Abstract [en]

    Cisplatin is part of the treatment regime of head and neck squamous cell carcinomas (HNSCC). In order to predict the clinical outcome of the treatment, markers for evaluation of the intrinsic cisplatin sensitivity are inquired. In this study we characterize the lysosomal compartment and compare cisplatin sensitivity in five HNSCC lines and normal oral keratinocytes (NOKs). Cisplatin sensitivity differed 3-fold between the least and most sensitive cell lines, and the cisplatin LD50 correlated significantly to lysosomal pH, which varied from 4.3 in NOKs to 4.9 in the most resistant HNSCC line. Lysosomes are acidified by the V0V1-ATPase complex located in the lysosomal membrane. Interestingly, in cell lines exhibiting high lysosomal pH, we found decreased expression of the V0V1-ATPase B2 subunit, possibly explaining the defective acidification. In all cell lines, exposure to cisplatin caused activation of caspase-3. Cisplatin exposure was accompanied by lysosomal membrane permeabilization and inhibition of the llysosomal cathepsins B, D and L partly prevented cell death. No correlation between cisplatin sensitivity and expression of cathepsins B, D and L or secretion of their respective proforms into the culture medium was found in the cell lines studied. We conclude that lysosomal pH and expression of V0V1-ATPase subunits are possible future markers of intrinsic cisplatin sensitivity.

    Place, publisher, year, edition, pages
    John Wiley & Sons, 2010
    Keywords
    apoptosis, cathepsin, chemotherapy resistance, lysosome, V0V1-ATPase
    National Category
    Cell and Molecular Biology
    Identifiers
    urn:nbn:se:liu:diva-15136 (URN)10.1002/hed.21317 (DOI)000281528100008 ()
    Note

    The previous status of this article was Manuscript and the working title was Radiation and cisplatin sensitivity in head and neck cancer cells with stem cell properties.

    Available from: 2008-10-17 Created: 2008-10-17 Last updated: 2018-02-12Bibliographically approved
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  • 83.
    Nilsson, Cathrine
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Johansson, Uno
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Johansson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Kågedal, Katarina
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Cytosolic acidification and lysosomal alkalinization during TNF-α induced apoptosis in U937 cells2006In: Apoptosis (London), ISSN 1360-8185, E-ISSN 1573-675X, Vol. 11, no 7, p. 1149-1159Article in journal (Refereed)
    Abstract [en]

    Apoptosis is often associated with acidification of the cytosol and since loss of lysosomal proton gradient and release of lysosomal content are early events during apoptosis, we investigated if the lysosomal compartment could contribute to cytosolic acidification. After exposure of U937 cells to tumor necrosis factor-α, three populations; healthy, pre-apoptotic, and apoptotic cells, were identified by flow cytometry. These populations were investigated regarding intra-cellular pH and apoptosis-associated events. There was a drop in cytosolic pH from 7.2 ± 0.1 in healthy cells to 6.8 ± 0.1 in pre-apoptotic, caspase-negative cells. In apoptotic, caspase-positive cells, the pH was further decreased to 5.7 ± 0.04. The cytosolic acidification was not affected by addition of specific inhibitors towards caspases or the mitochondrial F0F1-ATPase. In parallel to the cytosolic acidification, a rise in lysosomal pH from 4.3 ± 0.3, in the healthy population, to 4.8 ± 0.3 and 5.5 ± 0.3 in the pre-apoptotic- and apoptotic populations, respectively, was detected. In addition, lysosomal membrane permeability increased as detected as release of cathepsin D from lysosomes to the cytosol in pre-apoptotic and apoptotic cells. We, thus, suggest that lysosomal proton release is the cause of the cytosolic acidification of U937 cells exposed to TNF-α.

  • 84.
    Nilsson, Cathrine
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Kågedal, Katarina
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Johansson, Uno
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Analysis of cytosolic and lysosomal pH in apoptotic cells by flow cytometry2004In: Methods in Cell Science, ISSN 1381-5741, Vol. 25, no 3-4, p. 185-194Article in journal (Refereed)
    Abstract [en]

    Several reports indicate that the cytosol is acidified during apoptosis although the mechanism is not yet fully elucidated. The most acidic organelle found in the cell is the lysosome, raising the possibility that lysosomal proton release may contribute to the cytosolic acidification. We here describe methods for measurement of the cytosolic and lysosomal pH in U937 cells by a dual-emission ratiometric technique suitable for flow cytometry. Cytosolic pH was analysed in cells loaded with the fluorescent probe BCECF, while lysosomal pH was determined after endocytosis of FITC-dextran. Standard curves were obtained by incubating cells in buffers with different pH in the presence of the proton ionophore nigericin. Apoptosis was induced by exposure of cells to 10ng/ml TNF- for 4h, and apoptotic cells were identified using a fluorescent marker for active caspases. By gating of control and apoptotic cells, the cytosolic and lysosomal pH were calculated in each population. The cytosolic pH was found to decrease from 7.2 ± 0.1 to 5.8s±0.1 and the lysosomal increased from 4.3±0.4 to 5.2±0.3. These methods will be useful in future attempts to evaluate the involvement of lysosomes in the acidification of the cytosol during apoptosis.

  • 85.
    Nilsson, Cathrine
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Roberg, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Reconstruction Centre, Department of ENT - Head and Neck Surgery UHL.
    Grafström, Roland C.
    Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Intrinsic differences in cisplatin sensitivity of head and neck cancer celllines correlates to lysosomal pH2010In: Head and Neck, ISSN 1043-3074, E-ISSN 1097-0347, Vol. 32, no 9, p. 1185-1194Article in journal (Refereed)
    Abstract [en]

    Cisplatin is part of the treatment regime of head and neck squamous cell carcinomas (HNSCC). In order to predict the clinical outcome of the treatment, markers for evaluation of the intrinsic cisplatin sensitivity are inquired. In this study we characterize the lysosomal compartment and compare cisplatin sensitivity in five HNSCC lines and normal oral keratinocytes (NOKs). Cisplatin sensitivity differed 3-fold between the least and most sensitive cell lines, and the cisplatin LD50 correlated significantly to lysosomal pH, which varied from 4.3 in NOKs to 4.9 in the most resistant HNSCC line. Lysosomes are acidified by the V0V1-ATPase complex located in the lysosomal membrane. Interestingly, in cell lines exhibiting high lysosomal pH, we found decreased expression of the V0V1-ATPase B2 subunit, possibly explaining the defective acidification. In all cell lines, exposure to cisplatin caused activation of caspase-3. Cisplatin exposure was accompanied by lysosomal membrane permeabilization and inhibition of the llysosomal cathepsins B, D and L partly prevented cell death. No correlation between cisplatin sensitivity and expression of cathepsins B, D and L or secretion of their respective proforms into the culture medium was found in the cell lines studied. We conclude that lysosomal pH and expression of V0V1-ATPase subunits are possible future markers of intrinsic cisplatin sensitivity.

  • 86.
    Norberg, U.
    et al.
    Dept. of Transplant. and Liver Surg., Sahlgrenska Universitetssjukhuset, Gothenburg, Sweden.
    Soderlind, K.
    Franzén, Lennart
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Loven, C.
    Strandelius, E.
    Wolfbrandt, A.
    Backman, L.
    A modified 'Spanish model' for organ donation in the southeast region of Sweden2000In: Transplantation Proceedings, ISSN 0041-1345, E-ISSN 1873-2623, Vol. 32, no 1, p. 72-74Conference paper (Other academic)
    Abstract [en]

    [No abstract available]

  • 87.
    Nystrom, Sofie
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Nelson, Erin
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Reitan, Nina
    Norwegian University of Science and Technology.
    Ellingsen, Pal
    Norwegian University of Science and Technology.
    Brorsson, Ann-Christin
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Biotechnology. Linköping University, The Institute of Technology.
    Mason, Jeffrey
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Johansson, Leif
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Sluzny, Chanan
    Appl Spectral Imaging, Migdal Haemeq.
    Handrick, Susann
    Charite.
    Prokop, Stefan
    Charite.
    Wegenast-Braun, Bettina
    German Centre Neurodegenerat Disease.
    Hornemann, Simone
    University of Zurich Hospital.
    Kågedal, Katarina
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Lindgren, Mikael
    Norwegian University of Science and Technology.
    Heppner, Frank
    Charite.
    Jucker, Mathias
    German Centre Neurodegenerat Disease.
    Aguzzi, Adriano
    University of Zurich Hospital.
    Nilsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Hammarström, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biochemistry. Linköping University, The Institute of Technology.
    Monitoring amyloid formation and maturation in vitro and in vivo using LCO fluorescence in PRION, vol 6, issue , pp 13-132012In: PRION, Landes Bioscience , 2012, Vol. 6, p. 13-13Conference paper (Refereed)
    Abstract [en]

    n/a

  • 88.
    Olsson, Anders
    et al.
    Linköping University, Department of Medicine and Health Sciences, Internal Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Centre, Department of Endocrinology and Gastroenterology UHL.
    Yuan, XiMing
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Antioxidants in the prevention of atherosclerosis1996In: Current Opinion in Lipidology, ISSN 0957-9672, E-ISSN 1473-6535, Vol. 7, no 6, p. 374-80Article in journal (Refereed)
    Abstract [en]

    Four antioxidant treatment modalities against atherosclerosis and coronary heart disease are scrutinized: probucol, beta-carotene, alpha-tocopherol and anti-iron treatment. A pattern seems to have emerged in which some treatments look promising, but others are disappointing. Most published studies of antioxidation in atherosclerosis have been ad-hoc in that the primary endpoint of the study has not been a diagnosis related to atherosclerosis; this may be misleading. The most promising antioxidant seems to be alpha-tocopherol, supported by the results of the Cambridge Heart Antioxidant Study. Probucol has the drawback of decreasing high density lipoprotein concentration and is therefore unlikely to influence atheroma in people. beta-Carotene has been repeatedly shown to be ineffective against coronary heart disease. Anti-iron treatment has not yet been tested in animal models or in man. More has to be learned of the role of antioxidation in atherosclerosis before the effectiveness of this treatment modality can be established.

  • 89.
    Persson, H L
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Respiratory Medicine UHL.
    Vainikka, Linda K
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Lysosomal iron in pulmonary alveolar proteinosis: a case report.2009In: The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology, ISSN 1399-3003, Vol. 33, no 3, p. 673-679Article in journal (Refereed)
    Abstract [en]

    Pulmonary alveolar proteinosis is characterised by accumulation of surfactant-like material in the distal air spaces. Since lysosomes play a crucial role for degradation of large biomolecules taken up from the cell's environment, it was hypothesised that oxidant-induced lysosomal disruption and ensuing cell death might play a role in disease development. In the present study, alveolar macrophages, harvested by whole-lung lavage from a patient diagnosed with pulmonary alveolar proteinosis, are shown to contain large amounts of undigested material within lysosomes, and the same organelle exhibits increased amounts of haemosiderin-bound iron. Compared with murine macrophage-like J774 cells (iron exposed or not), the status of human macrophages was pro-oxidative, i.e. macrophages exhibited a low level of the antioxidant glutathione and large amounts of iron available for Fenton-type chemistry. As a consequence, macrophageal lysosomes were particularly fragile when exposed to physiological concentrations of hydrogen peroxide (generated by glucose oxidase in culture medium). Such lysosomal disruption resulted in extensive cell death by both necrosis and apoptosis independent of caspase-3 activation. Considering the potential role of iron-catalysed oxidant-induced lysosomal rupture and ensuing cell killing for pulmonary alveolar proteinosis pathology and disease progression, whole-lung lavage might be considered early in those cases in which cytochemical staining reveals great numbers of haemosiderin-laden alveolar macrophages.

  • 90.
    Persson, H.Lennart
    et al.
    Linköping University, Department of Neuroscience and Locomotion, Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Respiratory Medicine.
    Kurz, Tino
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Pharmacology .
    Eaton, John Wallace
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Brunk, Ulf
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Pharmacology .
    Radiation-induced cell death: Importance of lysosomal destabilization2005In: Biochemical Journal, ISSN 0264-6021, E-ISSN 1470-8728, Vol. 389, no 3, p. 877-884Article in journal (Refereed)
    Abstract [en]

    The mechanisms involved in radiation-induced cellular injury and death remain incompletely understood. In addition to the direct formation of highly reactive hydroxyl radicals (HO.) by radiolysis of water, oxidative stress events in the cytoplasm due to formation of H2O2 may also be important. Since the major pool of low-mass redox-active intracellular iron seems to reside within lysosomes, arising from the continuous intralysosomal autophagocytotic degradation of ferruginous materials, formation of H2O2 inside and outside these organelles may cause lysosomal labilization with release to the cytosol of lytic enzymes and low-mass iron. If of limited magnitude, such release may induce 'reparative autophagocytosis', causing additional accumulation of redox-active iron within the lysosomal compartment. We have used radio-resistant histiocytic lymphoma (J774) cells to assess the importance of intralysosomal iron and lysosomal rupture in radiation-induced cellular injury. We found that a 40 Gy radiation dose increased the 'loose' iron content of the (still viable) cells approx. 5-fold when assayed 24 h later. Cytochemical staining revealed that most redox-active iron was within the lysosomes. The increase of intralysosomal iron was associated with 'reparative autophagocytosis', and sensitized cells to Iysosomal rupture and consequent apoptotic/necrotic death following a second, much lower dose of radiation (20 Gy) 24 h after the first one. A high-molecular-mass derivative of desferrioxamine, which specifically localizes intralysosomally following endocytic uptake, added to the culture medium before either the first or the second dose of radiation, stabilized lysosomes and largely prevented cell death. These observations may provide a biological rationale for fractionated radiation. © 2005 Biochemical Society.

  • 91.
    Persson, Lennart
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Respiratory Medicine UHL.
    Brunk, Ulf
    Linköping University, Department of Medical and Health Sciences, Pharmacology. Linköping University, Faculty of Health Sciences.
    A lysosomotropic form of alpha-lipoic acid: a possible therapy of diabetic complications?2002In: Diabetologia, ISSN 0012-186X, E-ISSN 1432-0428, Vol. 45, p. A175-A175Article in journal (Other academic)
    Abstract [en]

    n/a

  • 92.
    Persson, Lennart
    et al.
    Linköping University, Department of Medicine and Health Sciences, Pulmonary Medicine . Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Respiratory Medicine.
    Vainikka, Linda
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    TNF-alpha preserves lysosomal stability in macrophages: A potential defense against oxidative lung injury2010In: TOXICOLOGY LETTERS, ISSN 0378-4274, Vol. 192, no 2, p. 261-267Article in journal (Refereed)
    Abstract [en]

    Iron-catalyzed oxidative damage on the respiratory epithelium is prevented by alveolar macrophages depositing iron inside their lysosomes. Bound in an un-reactive state to various metalloproteins, e.g. ferritin, most lysosomal iron is kept separated from reactive oxygen species (ROS) by intracellular anti-oxidative enzyme systems. Some ROS may, however, escape this protective shield of antioxidants, react with small amounts of free redox-active iron within lysosomes, thereby causing peroxidative damage on lysosomes and possibly also ensuing cell death. Since macrophages, containing large amounts of lysosomal iron, are very resistant to TNF-alpha, we hypothesized that this cell type has developed specific defense mechanisms against TNF-alpha-induced ROS generation. Murine macrophages were exposed (or not) to non-toxic concentrations of TNF-alpha and/or iron and were then challenged with H2O2. Iron-exposed oxidatively stressed cells exhibited extensive lysosomal disruption resulting in pronounced cell death. In contrast, TNF-alpha stabilized lysosomes and protected cells, particularly those iron-exposed, by reducing cellular iron and increasing H-ferritin. Intracellular generation of H2O2 under oxidative stress was kept unchanged by TNF-alpha and/or iron. However, TNF-alpha increased basal levels of glutathione by up-regulating the synthesis of gamma-glutamylcystein synthetase, thereby strengthening the anti-oxidative capacity. TNF-alpha inhibitors would block this novel anti-oxidative defense system, possibly explaining their adverse effects on the lung.

  • 93.
    Persson, Lennart
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Respiratory Medicine UHL.
    Vainikka, Linda
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Eriksson, Hanna
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology.
    Wennerstrom, Urban
    Hospital Vastervik.
    Lane-Hamilton Syndrome Ferritin Protects Lung Macrophages Against Iron and Oxidation2011In: CHEST, ISSN 0012-3692, Vol. 139, no 2, p. 361-367Article in journal (Refereed)
    Abstract [en]

    Background: Lysosomal disruption and consequent apoptosis have been implicated in lung diseases characterized by iron overload. Free reactive iron in lysosomes sensitizes cells to oxidative stress. Apoptosis is prevented by heavy-chain (H)-ferritin, which can incorporate lysosomal iron into ferritin molecules. Tumor necrosis factor (TNF)-alpha stimulates the synthesis of H-ferritin. Idiopathic pulmonary hemosiderosis presents with the accumulation of iron and the upregulation of ferritin synthesis. We therefore analyzed the lysosomal response to oxidants and the role of H-ferritin synthesis in lung macrophages (LMs) harvested from the first Swedish case, to our knowledge, of Lane-Hamilton syndrome. Methods: Iron-exposed murine macrophages were used as a reference. Both cell types were stimulated with TNF-alpha (or not), then iron was assessed cytochemically and by atomic absorption spectrophotometry. H-ferritin expression was analyzed by Western blot and reduced glutathione (GSH) by spectrofluorometry. Following exposure to hydrogen peroxide, lysosomal membrane integrity and DNA degradation were analyzed by flow cytometry, whereas morphologic signs of apoptosis and necrosis were assessed by light microscopy. Results: GSH levels were approximately equal in LMs and murine macrophages. Although LMs contained much more iron than murine macrophages, lysosomal iron was bound in a harmless unreactive state by ample amounts of ferritin and hemosiderin, its lysosomal degradation product. Therefore, lysosomes of LMs were more oxidant resistant, and these cells were more adept at surviving oxidative stress. In both cell types, TNF-alpha prevented oxidant-induced lysosomal damage and cell death by upregulating synthesis of H-ferritin and GSH. Conclusions: Iron-overloaded LMs are equipped with an efficient armor of antioxidative mechanisms of which H-ferritin and hemosiderin seem to be particularly important.

  • 94.
    Persson, Lennart
    et al.
    Linköping University, Department of Medical and Health Sciences, Pulmonary Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Respiratory Medicine.
    Vainikka, Linda
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Sege, Maria
    Linköping University, Department of Medical and Health Sciences, Pulmonary Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Respiratory Medicine.
    Wennerström, Urban
    Division of Medicine, Hospital of Västervik, Västervik, Sweden.
    Dam-Larsen, Sören
    Division of Medicine, Hospital of Eksjö, Eksjö, Sweden.
    Persson, Jenny
    Division of Pulmonary Medicine, Ryhov Hospital, Jönköping, Sweden.
    Leaky lysosomes in lung transplant macrophages: azithromycin prevents oxidative damage2012In: Respiratory research (Online), ISSN 1465-9921, E-ISSN 1465-993X, Vol. 13, no 83Article in journal (Refereed)
    Abstract [en]

    Background: Lung allografts contain large amounts of iron (Fe), which inside lung macrophages may promote oxidative lysosomal membrane permeabilization (LMP), cell death and inflammation. The macrolide antibiotic azithromycin (AZM) accumulates 1000-fold inside the acidic lysosomes and may interfere with the lysosomal pool of Fe. Objective: Oxidative lysosomal leakage was assessed in lung macrophages from lung transplant recipients without or with AZM treatment and from healthy subjects. The efficiency of AZM to protect lysosomes and cells against oxidants was further assessed employing murine J774 macrophages. Methods: Macrophages harvested from 8 transplant recipients (5 without and 3 with ongoing AZM treatment) and 7 healthy subjects, and J774 cells pre-treated with AZM, a high-molecular-weight derivative of the Fe chelator desferrioxamine or ammonium chloride were oxidatively stressed. LMP, cell death, Fe, reduced glutathione (GSH) and H-ferritin were assessed. Results: Oxidant challenged macrophages from transplants recipients without AZM exhibited significantly more LMP and cell death than macrophages from healthy subjects. Those macrophages contained significantly more Fe, while GSH and H-ferritin did not differ significantly. Although macrophages from transplant recipients treated with AZM contained both significantly more Fe and less GSH, which would sensitize cells to oxidants, these macrophages resisted oxidant challenge well. The preventive effect of AZM on oxidative LMP and J774 cell death was 60 to 300 times greater than the other drugs tested. Conclusions: AZM makes lung transplant macrophages and their lysososomes more resistant to oxidant challenge. Possibly, prevention of obliterative bronchiolitis in lung transplants by AZM is partly due to this action.

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  • 95.
    Samuelsson, Martin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Psychiatry. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in Central Östergötland, Department of Psychiatry.
    Gerdin, George
    Linköping University, Department of Clinical and Experimental Medicine, Psychiatry. Linköping University, Faculty of Health Sciences.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Vrethem, Magnus
    Linköping University, Department of Clinical and Experimental Medicine, Neurology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in Central Östergötland, Department of Neurology.
    Taurine and glutathione levels in plasma before and after ECT treatment2012In: Psychiatry Research, ISSN 0165-1781, E-ISSN 1872-7123, Vol. 198, no 1, p. 53-57Article in journal (Refereed)
    Abstract [en]

    Taurine has been shown to be elevated in plasma and lymphocytes of depressed patients, but the level normalises after successful drug therapy. During depression, levels of glutathione (GSH) are decreased in the plasma and blood. This study was performed to examine taurine and GSH levels in depressed patients before and after electroconvulsive therapy (ECT). Fasting blood samples were collected from 23 patients before the first and after the third ECT treatment. The severity of depression was estimated with the Montgomery–Åsberg Depression Rating Scale (MADRS). We analysed GSH in blood and the levels of taurine and total GSH in plasma. After three ECTs, a significant decrease in MADRS scores was found for the entire group. Simultaneously, the decrease in the plasma taurine levels was significant for the seven responders but not for the sixteen non-responders. We observed no differences in blood or plasma GSH levels after three ECT treatments when compared to values before the therapy. Plasma taurine levels decrease significantly after three ECT treatments in patients who respond to treatment. GSH levels were not affected by ECT treatment. The results indicate that taurine may play a role in the pathophysiology of depression.

  • 96.
    Samuelsson, Martin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Psychiatry. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in Central Östergötland, Department of Psychiatry.
    Skogh, Elisabeth
    Linköping University, Department of Clinical and Experimental Medicine, Psychiatry. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in Central Östergötland, Department of Psychiatry.
    Lundberg, Kristina
    Linköping University, Department of Clinical and Experimental Medicine, Psychiatry. Linköping University, Faculty of Health Sciences.
    Vrethem, Magnus
    Linköping University, Department of Clinical and Experimental Medicine, Neurology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in Central Östergötland, Department of Neurology.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Taurine and glutathione in plasma and cerebrospinal fluid in olanzapine treated patients with schizophrenia2013In: Psychiatry Research, ISSN 0165-1781, E-ISSN 1872-7123, Vol. 210, no 3, p. 819-824Article in journal (Refereed)
    Abstract [en]

    Objectives: Oxidative stress has been implicated in the pathophysiology of schizophrenia. Taurine and glutathione (GSH) have antioxidant and central nervous system protective properties and are proposed to be involved in the pathology of schizophrenia. The aim of this study was to compare the blood and cerebrospinal fluid (CSF) levels of taurine and GSH in patients with schizophrenia medicated with oral olanzapine compared with controls.

    Methods: In total, 37 patients with schizophrenia being medicated with olanzapine and 45 healthy volunteers were recruited. Taurine and GSH levels were analysed in plasma and CSF and correlated to symptoms and level of function.

    Results: Plasma taurine levels were elevated in patients compared with controls (p=0.000003). No differences were found between patients and controls regarding taurine in CSF or GSH concentrations in plasma and CSF.

    Conclusion: The significantly higher levels of plasma but not CSF taurine in patients with schizophrenia treated with olanzapine compared with controls may implicate the involvement of taurine in the pathophysiology of the disease. The absence of GSH differences in plasma and CSF between patients and controls is interesting in the perspective of earlier research proposing a dysregulation of GSH metabolism as a vulnerability factor for the development of schizophrenia.

  • 97.
    Samuelsson, Martin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Psychiatry. Linköping University, Faculty of Health Sciences.
    Vainikka, Linda
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Nordin, Conny
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Glutathione In Blood And Cerebrospinal Fluid2008Conference paper (Refereed)
  • 98.
    Samuelsson, Martin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Psychiatry. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in Central Östergötland, Department of Psychiatry.
    Vainikka, Linda
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Glutathione in the blood and cerebrospinal fluid: A study in healthy male volunteers2011In: Neuropeptides, ISSN 0143-4179, E-ISSN 1532-2785, Vol. 45, no 4, p. 287-292Article in journal (Refereed)
    Abstract [en]

    Glutathione (GSH) is an important regulator of intracellular redox homeostasis. In the brain, glutathione is considered a major antioxidant, which is also found at high concentrations in the extracellular environment. Altered GSH balance in plasma, blood and cerebrospinal fluid (CSF) has been observed in several disorders suggesting that an impaired antioxidant function is part of the pathophysiology. The aim of the present study was to investigate a possible relationship between glutathione in plasma and CSF. Blood samples were collected from 26 healthy male volunteers at 8 a.m., noon, 4 p.m. and 8 p.m. At 8 a.m. the following morning, blood was drawn and three 6-ml fractions of CSF were collected by lumbar puncture. In CSF, a disrupted gradient was found showing the highest glutathione concentration in the second compared to the first and third fraction (P andlt; 0.002). Moreover, correlation and regression analyses between glutathione in plasma and CSF revealed an association between the third fraction CSF and plasma glutathione 8 p.m. the day before lumbar puncture. Thus, if carefully standardised due to the disrupted gradient in CSF, it might be possible to estimate glutathione levels in CSF by analysing plasma in healthy males.

  • 99. Order onlineBuy this publication >>
    Stroikin, Yuri
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Ageing-associated changes of lysosomal compartment: implications on cellular functions2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The lysosomal compartment is a major site for intracellular degradation. Lysosomal degradation of the cell’s own constituents, so-called autophagy, not only provides a cell with nutrients, but also removes damaged and potentially dangerous endogenous structures, thus securing intracellular homeostasis. On the other hand, lysosomes have been shown to be involved in the initial stages of apoptosis, and the protective effect of autophagy has been suggested to switch to cell death when excessive.

    Ageing-related changes of cellular structures result from damage caused by eactive oxygen species (ROS), which are an inevitable by-product of aerobic life. Intracellular turnover of compromised organelles and macromolecules, to which lysosomal degradation is a major contributor, does not function perfectly, even under favourable conditions. This inherent incompleteness of lysosomal degradation is responsible for the accumulation of a variety of nondegraded and functionally inefficient structures, which can be considered biological “garbage”. Biological “garbage” includes damaged non-degraded macromolecules and organelles, as well as intralysosomal non-degradable polymer-like structure called lipofuscin, or age pigment. Although accumulation of biological “garbage” has been suggested harmful, little is known about the mechanisms of its deleterious effects.

    To gain a better understanding of ageing-related changes of the lysosomal compartment and their influence on cell functions, we focused on studying: (1) the role of macroautophagy in the turnover of organelles and lipofuscin formation; (2) the role of biological “garbage” accumulation in the development of ageing-related changes and eventual death of growth-arrested, postmitotic-like cells; (3) the possible cell-protective effect of mitosis; (4) the influence of lipofuscin on cell survival during complete starvation; and (5) the effects of lipofuscin on lysosomal stability.

    As a model of induced biological “garbage” accumulation we used confluent human fibroblasts treated with the autophagy inhibitor 3-methyladenine (3MA). Alternatively, lysosomal degradation was suppressed by using the cysteine protease inhibitor leupeptin, or the cathepsin D inhibitor pepstatin A. As a cellular model of aged cells, we used lipofucsin-loaded human fibroblasts. Lipofuscin-loading was achieved by culturing confluent fibroblasts under hyperoxic conditions for 2-4 months. Using these in vitro models, the present study shows that: (1) inhibition of autophagy results in accumulation of lysosome-associated autofluorescent material and mitochondria with low membrane potential; (2) detrimental effect of biological “garbage” accumulation following inhibition of autophagy is prevented by continuous cell division; (3) lipofuscin-loaded cells are more resistant to starvation-induced cell death than control cells; (4) lysosomes of lipofuscinloaded fibroblasts are more resistant to the organelle-targeted stress then lysosomes of control cells.

    Based on the results of the present study we conclude that properly operating autophagic machinery plays a crucial role in preventing age-related changes associated with accumulation of biological “garbage”. We also suggest that continual proliferation is the natural mechanism by which cells cope with the accumulation of non-degradable material, employing mechanical dilution during the cell division. Finally, we introduce an idea of lipofuscin being a hormetic agent, and possibly possessing some lysosome-stabilising properties. Better understanding of the influence of the age-related accumulation of biological “garbage” on cellular functions may be helpful for future development of anti-ageing therapy and management of age-associated pathologies.

    List of papers
    1. Inhibition of autophagy with 3-methyladenine results in impaired turnover of lysosomes and accumulation of lipofuscin-like material
    Open this publication in new window or tab >>Inhibition of autophagy with 3-methyladenine results in impaired turnover of lysosomes and accumulation of lipofuscin-like material
    2004 (English)In: European journal of cell biology, ISSN 0171-9335, Vol. 83, no 10, p. 583-590Article in journal (Refereed) Published
    Abstract [en]

    Autophagy (which includes macro-, micro-, and chaperone-mediated autophagy) is an important biological mechanism for degradation of damaged/obsolete macromolecules and organelles. Ageing non-dividing cells, however, progressively accumulate oxidised proteins, defective organelles and intralysosomal lipofuscin inclusions, suggesting inherent insufficiency of autophagy. To learn more about the role of macroautophagy in the turnover of organelles and lipofuscin formation, we inhibited autophagic sequestration with 3-methyladenine (3 MA) in growth-arrested human fibroblasts, a classical model of cellular ageing. Such treatment resulted in a dramatic accumulation of altered lysosomes, displaying lipofuscin-like autofluorescence, as well as in a moderate increase of mitochondria with lowered membrane potential. The size of the late endosomal compartment appeared not to be significantly altered following 3 MA exposure. The accumulation of lipofuscin-like material was enhanced when 3 MA administration was combined with hyperoxia. The findings suggest that macroautophagy is essential for normal turnover of lysosomes. This notion is supported by reports in the literature of lysosomal membrane proteins inside lysosomes and/or late endosomes, as well as lysosomes with active hydrolases within autophagosomes following vinblastine-induced block of fusion between lysosomes and autophagosomes. The data also suggest that specific components of lysosomes, such as membranes and proteins, may be direct sources of lipofuscin.

    Keywords
    Ageing, Autophagocytosis, Fibroblasts, Lysosomes, 3-Methyladenine
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-14211 (URN)10.1078/0171-9335-00433 (DOI)
    Available from: 2007-01-09 Created: 2007-01-09 Last updated: 2009-06-04
    2. Testing the “garbage” accumulation theory of ageing: mitotic activity protects cells from death induced by inhibition of autophagy
    Open this publication in new window or tab >>Testing the “garbage” accumulation theory of ageing: mitotic activity protects cells from death induced by inhibition of autophagy
    2005 (English)In: Biogerontology, ISSN 1389-5729, Vol. 6, no 1, p. 39-47Article in journal (Refereed) Published
    Abstract [en]

    Imperfect autophagic degradation of oxidatively damaged macromolecules and organelles (so-called biological garbage) is considered an important contributor to ageing and consequent death of postmitotic (non-dividing) cells, such as neurons and cardiac myocytes. In contrast, proliferating cells apparently escape senescence by a continuous dilution and repair of damaged structures during division. Postmitotic ageing can be mimicked and studied in cultures of potentially dividing cells if their mitotic activity is inhibited. To test the garbage accumulation theory of ageing, we compared survival of density-dependent growth-arrested (confluent) and proliferating human fibroblasts and astrocytes following inhibition of autophagic sequestration with 3-methyladenine (3MA). Exposure of confluent fibroblast cultures to 3MA for two weeks resulted in a significantly increased proportion of dying cells compared to both untreated confluent cultures and dividing cells with 3MA-inhibited autophagy. Similar results were obtained when autophagic degradation was suppressed by the protease inhibitor leupeptin. In 3MA- or leupeptin-exposed cultures, dying cells were overloaded with undegraded autofluorescent material. The results support a key role of biological lysosomal garbage accumulation in the triggering of ageing and death of postmitotic cells, as well as the anti-ageing role of cell division.

    Keywords
    ageing, apoptosis, astrocytes, autophagocytosis, fibroblasts, 3-methyladenine, leupeptin, mitosis
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-14212 (URN)10.1007/s10522-004-7382-y (DOI)
    Available from: 2007-01-09 Created: 2007-01-09 Last updated: 2009-06-04
    3. Increased resistance of lipofuscin-loaded prematurely senescent fibroblasts to starvation-induced programmed cell death
    Open this publication in new window or tab >>Increased resistance of lipofuscin-loaded prematurely senescent fibroblasts to starvation-induced programmed cell death
    2007 (English)In: Biogerontology (Dordrecht), ISSN 1389-5729, E-ISSN 1573-6768, Vol. 8, no 1, p. 43-53Article in journal (Refereed) Published
    Abstract [en]

    Alterations of cellular structures often found in ageing cells is mainly the result of production of reactive oxygen species and a consequence of aerobic life. Both oxidative stress and decreased degradative capacity of lysosomal system cause accumulation of intralysosomal age-related pigment called lipofuscin. To investigate the influence of lipofuscin on cell function, we compared survival of lipofuscin-loaded and control human fibroblasts following complete starvation induced by exposure to phosphate-buffered saline (PBS). Starving of control fibroblasts resulted in lysosomal alkalinisation, relocation of cathepsin D to the cytosol, caspase-3 activation and, finally, cell death, which became evident 72 h after the start of exposure to PBS. Increase of lysosomal pH was significantly less prominent in lipofuscin-loaded cells than in controls and was accompanied neither by leakage of cathepsin D nor by caspase-3 activation even 96 h after the initiation of starvation. Suppression of autophagy by 3-methyladenine (3-MA) accelerated cell death, while inhibition of cathepsin D delayed it, implying an important role of autophagy in cell survival during starvation and showing the involvement of lysosomes in starvation-induced cell death. Disturbed apoptotic response found in lipofuscin-loaded cells can be interpreted as an example of hormesis—an adaptation to low doses of otherwise harmful agents, in this case of lipofuscin, which has a protective effect at moderate amounts but becomes toxic at large quantities.

    Keywords
    Ageing, Apoptosis, Autophagy, Cathepsin D, Hormesis, Lysosomal pH, 3-Methyladenine, Pepstatin A
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-14213 (URN)10.1007/s10522-006-9029-7 (DOI)
    Available from: 2007-01-09 Created: 2007-01-09 Last updated: 2017-12-13
    4. Lysosome-targeted stress reveals increased stability of lipofuscin-containing lysosomes
    Open this publication in new window or tab >>Lysosome-targeted stress reveals increased stability of lipofuscin-containing lysosomes
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    2008 (English)In: Age (Omaha), ISSN 0161-9152, E-ISSN 1574-4647, Vol. 30, no 1, p. 31-42Article in journal (Refereed) Published
    Abstract [en]

    Cellular ageing is associated with accumulation of undegradable intralysosomal material, called lipofuscin. In order to accelerate the lipofuscin-accumulation, confluent, growth arrested human fibroblasts were cultured under hyperoxic conditions. To provide a better insight into the effects of lipofuscin on cellular functions, we compared lysosomal stability in control and lipofuscin-loaded human fibroblasts under conditions of lysosome-targeted stress induced by exposure to either the lysosomotropic detergent MSDH or the redox-cycling quinone naphthazarin. We show that lysosomal damage, assessed by acridine-orange relocation, translocation of cathepsin D to the cytosol, and alkalinization of lysosomes is more pronounced in control than in lipofuscin-loaded fibroblasts. Finding that lysosomal integrity was less affected or even preserved in case of lipofuscin-loaded cells enables us to suggest that lipofuscin exerts lysosome-stabilizing properties.

    Place, publisher, year, edition, pages
    Springer, 2008
    Keywords
    alkalinization, autophagolysosomes, bafilomycin A1, cathepsin D, MSDH, naphthazarin quinone
    National Category
    Physiology Pathobiology Pharmacology and Toxicology
    Identifiers
    urn:nbn:se:liu:diva-11051 (URN)10.1007/s11357-007-9045-9 (DOI)
    Note

    Note: Because of an embargo period with Springer journals, the full text will become available at LiU E-Press, January 2009. Original publication: Yuri Stroikin, Hanna Mild, Uno Johansson, Karin Roberg and Karin Öllinger, Lysosome-targeted stress reveals increased stability of lipofuscin-containing lysosomes, 2008, AGE http://dx.doi.org/10.1007/S11357-007-9045-9. Copyright: The original publication is available at http://www.springerlink.com

    The previous status of this article was Manuscript and the working title was Lipofuscin preserves lysosome integrity under conditions of organelle-targeted stress.

    Available from: 2009-01-12 Created: 2008-04-15 Last updated: 2018-01-13
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  • 100.
    Stroikin, Yuri
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Dalen, Helge
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Brunk, Ulf T.
    Linköping University, Department of Medicine and Health Sciences, Pharmacology . Linköping University, Faculty of Health Sciences.
    Terman, Alexei
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Testing the “garbage” accumulation theory of ageing: mitotic activity protects cells from death induced by inhibition of autophagy2005In: Biogerontology, ISSN 1389-5729, Vol. 6, no 1, p. 39-47Article in journal (Refereed)
    Abstract [en]

    Imperfect autophagic degradation of oxidatively damaged macromolecules and organelles (so-called biological garbage)