Aldosterone stimulates proliferation of mesangial cells by activating mitogen-activated protein kinase 1/2, cyclin D1, and cyclin A.
Recently, attention has been focused on the role of aldosterone in the pathophysiology of hypertension and cardiovascular disease. Several clinical and experimental data support the hypothesis that aldosterone contributes to the progression of renal injury. However, the molecular mechanisms of the effects of aldosterone in signal transduction and the cell-cycle progression of mesangial cells are not well known. For determining the signaling pathway of aldosterone in cultured mesangial cells, the effects of aldosterone on the mitogen-activated protein kinase 1/2 (MAPK1/2) pathway and the promoter activities of cyclin D1, cyclin A, and cyclin E were investigated. First, it was shown that the mineralocorticoid receptor (MR) was expressed in rat mesangial cells and glomeruli and that aldosterone stimulated the proliferation of mesangial cells via the MR and MAPK1/2 pathway. Next, it was demonstrated that aldosterone stimulated Ki-RasA, c-Raf kinase, MEK1/2, and MAPK1/2 in rat mesangial cells. Aldosterone induced cyclin D1 and cyclin A promoter activities and protein expressions, as well as the increments of CDK2 and CDK4 kinase activities. The presence of CYP11B2 and 11beta-HSD2 mRNA in rat mesangial cells also was shown. In conclusion, aldosterone seems to exert mainly MR-induced effects that stimulate c-Raf, MEK1/2, MAPK1/2, the activities of CDK2 and CDK4, and the cell-cycle progression in mesangial cells. MR antagonists may serve as a potential therapeutic approach to mesangial proliferative disease.
Department of Nephrology, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. yterada.kid@tmd.ac.jp
Yoshio
Y
Terada
Takahiko
T
Kobayashi
Hitoshi
H
Kuwana
Hiroyuki
H
Tanaka
Seiji
S
Inoshita
Michio
M
Kuwahara
Sei
S
Sasaki
D043209:11-beta-Hydroxysteroid Dehydrogenase Type 2 / Q000378:metabolism; D000450:Aldosterone / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D015153:Blotting, Western; D002453:Cell Cycle; D049109:Cell Proliferation; D019925:Cyclin A / Q000235:genetics / Q000378:metabolism*; D019938:Cyclin D1 / Q000235:genetics / Q000378:metabolism*; D019927:Cyclin E / Q000235:genetics; D019405:Cytochrome P-450 CYP11B2 / Q000378:metabolism; D018450:Disease Progression; D005434:Flow Cytometry; D017930:Genes, Reporter; D007668:Kidney / Q000166:cytology / Q000293:injuries / Q000473:pathology; D007672:Kidney Cortex / Q000378:metabolism; D007678:Kidney Glomerulus / Q000378:metabolism; D008156:Luciferases / Q000378:metabolism; D020935:MAP Kinase Signaling System; D008297:Male; D050527:Mesangial Cells / Q000378:metabolism* / Q000473:pathology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000737:chemistry; D019908:Proto-Oncogene Proteins c-raf / Q000378:metabolism; D016283:Proto-Oncogene Proteins p21(ras); D051381:Rats; D017207:Rats, Sprague-Dawley; D018161:Receptors, Mineralocorticoid / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013936:Thymidine / Q000378:metabolism; D013997:Time Factors; D014162:Transfection; D018631:ras Proteins
D019925:Cyclin A; D019927:Cyclin E; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D018161:Receptors, Mineralocorticoid; D019938:Cyclin D1; D000450:Aldosterone; D043209:11-beta-Hydroxysteroid Dehydrogenase Type 2; D008156:Luciferases; D019405:Cytochrome P-450 CYP11B2; D019908:Proto-Oncogene Proteins c-raf; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins; D013936:Thymidine