Involvement of aldosterone and mineralocorticoid receptors in rat mesangial cell proliferation and deformability
Involvement of aldosterone and mineralocorticoid receptors in rat mesangial cell proliferation and deformability
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DOI：
10.1161/01.hyp.0000154681.38944.9a
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发表时间：
2005-04-01
期刊：
影响因子：
8.3
通讯作者：
Abe, Y
中科院分区：
文献类型：
--
作者：
Nishiyama, A;Yao, L;Abe, Y
我们最近证明，长期给药醛固酮会诱导大鼠肾小球系膜损伤，并激活丝裂原激活的蛋白激酶，包括细胞外信号调节激酶1/2 （ERK1/2）。我们还观察到，醛固酮诱导的肾小球系膜损伤和ERK1/2激活可以通过选择性矿化皮质激素受体（MR）拮抗剂eplerenone来阻止，这表明肾小球系膜是醛固酮通过MR激活诱导的损伤的潜在靶点。在本研究中，我们研究了MR是否在培养的大鼠系膜细胞（RMCs）中表达并参与醛固酮诱导的RMC损伤。采用Western blotting分析和荧光标记方法评价MR的表达和定位。细胞增殖和微力学性能分别由[H-3]-胸苷摄取测量和原子力显微镜悬臂纳米压痕技术测定。用抗磷酸化ERK1/2抗体Western blotting分析ERK1/2活性。蛋白表达和免疫染色显示mrcs细胞质中MR含量丰富。醛固酮（1 ~ 100 nmol/L）剂量依赖性地激活RMCs中的ERK1/2，在10分钟达到峰值。eplerenone预处理（10 μ mol/L）显著减弱醛固酮诱导的ERK1/2磷酸化。醛固酮（100 nmol/L）处理30 h后，[H-3]胸苷结合增加，弹性模量降低，表明醛固酮具有细胞增殖和变形作用。eplerenone或ERK （MEK）抑制剂PD988059 （100 μ mol/L）预处理可阻止这些醛固酮诱导的细胞特性变化。结果表明，醛固酮通过MR和ERK1/2激活直接诱导RMC增殖和变形，可能参与肾小球系膜损伤的发病机制。
We demonstrated recently that chronic administration of aldosterone to rats induces glomerular mesangial injury and activates mitogen-activated protein kinases including extracellular signal-regulated kinases 1/2 (ERK1/2). We also observed that the aldosterone-induced mesangial injury and ERK1/2 activation were prevented by treatment with a selective mineralocorticoid receptor (MR) antagonist, eplerenone, suggesting that the glomerular mesangium is a potential target for injuries induced by aldosterone via activation of MR. In the present study, we investigated whether MR is expressed in cultured rat mesangial cells (RMCs) and involved in aldosterone-induced RMC injury. MR expression and localization were evaluated by Western blotting analysis and fluorolabeling methods. Cell proliferation and micromechanical properties were determined by [H-3]-thymidine uptake measurements and a nanoindentation technique using an atomic force microscope cantilever, respectively. ERK1/2 activity was measured by Western blotting analysis with an anti-phospho-ERK1/2 antibody. Protein expression and immunostaining revealed that MR was abundant in the cytoplasm of RMCs. Aldosterone (1 to 100 nmol/L) dose-dependently activated ERK1/2 in RMCs with a peak at 10 minutes. Pretreatment with eplerenone (10 mu mol/L) significantly attenuated aldosterone-induced ERK1/2 phosphorylation. Aldosterone (100 nmol/L) treatment for 30 hours increased [H-3]-thymidine incorporation and decreased the elastic modulus, indicating cellular proliferative and deforming effects of aldosterone, respectively. These aldosterone-induced changes in cellular characteristics were prevented by pretreatment with eplerenone or an ERK (MEK) inhibitor, PD988059 (100 mu mol/L). The results indicate that aldosterone directly induces RMC proliferation and deformability through MR and ERK1/2 activation, which may contribute to the pathogenesis of glomerular mesangial injury.