Neonatal Losartan Treatment Suppresses Renal Expression of Molecules Involved in Cell-Cell and Cell-Matrix Interactions
2004 (English)In: Journal of the American Society of Nephrology, ISSN 1046-6673, Vol. 15, no 5, 1232-1243 p.Article in journal (Refereed) Published
Lack of neonatal angiotensin II type I receptor (AT1) stimulation produces renal abnormalities characterized by papillary atrophy and impaired urinary concentrating ability, but the mechanisms involved are still unclear. DNA microarray was used to identify genes that are differentially expressed in renal medulla in response to neonatal treatment with AT 1 receptor antagonist losartan (30 mg/kg per d), which commenced within 24 h after birth. The data showed that losartan treatment for 48 h downregulated 68 genes, ~30% of which encode various components of cytoskeleton and cytoskeleton-associated proteins, extracellular matrix, and enzymes involved in extracellular matrix maturation or turnover. With the use of immunohistochemistry and Western immunoblot, the microarray data were confirmed and it was demonstrated that losartan suppressed renal expression of syndecan 2, a-smooth muscle actin, MHC class II, and leukocyte type 12-lipoxygenase by day 4. In addition, losartan inhibited medullary expression of integrin a6 and caused relocalization of integrins a6 and a3. Moreover, losartan inhibited cell proliferation in medullary tubules by day 9, as detected by Ki-67 immunostaining. This study provides new data supporting the contention that a lack of AT1 receptor stimulation results in abnormal matrix assembly, disturbed cell-cell and cell-matrix interactions, and subsequent abnormal tubular maturation. Moreover, regulation of the expression of leukocyte type 12-lipoxygenase and a-smooth muscle actin by the renin-angiotensin system in the immature kidney adds new knowledge toward the understanding of renal vascular development.
Place, publisher, year, edition, pages
Lippincott Williams & Wilkins, 2004. Vol. 15, no 5, 1232-1243 p.
National CategoryUrology and Nephrology
IdentifiersURN: urn:nbn:se:liu:diva-45754DOI: 10.1097/01.ASN.0000123690.75029.3FISI: 000221043000017PubMedID: 15100363ScopusID: 2-s2.0-1942474529OAI: oai:DiVA.org:liu-45754DiVA: diva2:266650