title: Aldosterone upregulates vascular endothelial growth factor expression in mouse cortical collecting duct epithelial cells through classic mineralocorticoid receptor.
abstract: Accumulating evidence shows that aldosterone plays an important role in the pathogenesis of renal fibrosis but its mechanism has not been completely defined. Recently, exogenous administration of aldosterone significantly alleviated ischemic states in a model of femoral artery ligated rats, accompanied by an obvious enhancement of VEGF upregulation. We hypothesized that aldosterone may also regulate the expression of VEGF in the kidney. To confirm this, cultured cortical collecting duct epithelial cells (M-1 cell line) were incubated with aldosterone and control media, respectively. The pathway by which aldosterone regulates VEGF expression was tested by the administration of spironolactone, a specific mineralocorticoid receptor (MR) antagonist. VEGF expression was detected by immunofluorescence staining, ELISA, Western blot and RT-PCR. Aldosterone induced an elevation of VEGF excretion in a time- and dose-dependent manner. Western blotting showed a 1.4-fold elevation in cytosolic VEGF expression following aldosterone (10(-8) M) incubation for 48 h (p<0.01). After aldosterone (10(-7) M) incubation for 48 h, the mRNA level of VEGF164 and VEGF120 showed 1.8- and 1.7-fold increases, respectively (p<0.01). This upregulation was almost completely blocked by spironolactone as shown both by mRNA levels and cytosolic protein levels. In addition, the mRNA of aldosterone receptor was detected in M-1 cells. We demonstrated for the first time that aldosterone induced VEGF expression in M-1 cells, an effect mediated by classic mineralocorticoid receptor. This finding provides experimental evidence for the local non-hemodynamic action of aldosterone.
authors.affiliation: Division of Nephrology, Huashan Hospital, Fudan University, Shanghai, PR China.
authors.forename: Lingyun
authors.initials: L
authors.lastname: Lai
authors.forename: Ai
authors.initials: A
authors.lastname: Pen
authors.forename: Yeshi
authors.initials: Y
authors.lastname: Hu
authors.forename: Ji
authors.initials: J
authors.lastname: Ma
authors.forename: Jin
authors.initials: J
authors.lastname: Chen
authors.forename: Chuan-Ming
authors.initials: CM
authors.lastname: Hao
authors.forename: Yong
authors.initials: Y
authors.lastname: Gu
authors.forename: Shanyan
authors.initials: S
authors.lastname: Lin
mesh_terms: D000450:Aldosterone / Q000494:pharmacology*; D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D007672:Kidney Cortex / Q000187:drug effects / Q000378:metabolism*; D007685:Kidney Tubules, Collecting / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D018613:Microscopy, Confocal; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D018161:Receptors, Mineralocorticoid / Q000187:drug effects*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation / Q000187:drug effects; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis*
chemical_list: D012333:RNA, Messenger; D018161:Receptors, Mineralocorticoid; D042461:Vascular Endothelial Growth Factor A; D000450:Aldosterone