Aldosterone stimulates vascular smooth muscle cell proliferation via big mitogen-activated protein kinase 1 activation
Aldosterone stimulates vascular smooth muscle cell proliferation via big mitogen-activated protein kinase 1 activation
复制标题
DOI：
10.1161/01.hyp.0000172622.51973.f5
复制
发表时间：
2005-10-01
期刊：
影响因子：
8.3
通讯作者：
Yoshizumi, M
中科院分区：
文献类型：
--
作者：
Ishizawa, K;Izawa, Y;Yoshizumi, M
醛固酮的非基因组效应与多种心血管疾病的发病机制有关。醛固酮诱导的非基因组效应部分归因于细胞外信号调节激酶1/2(ERK1/2)的激活，ERK1/2是一种经典的丝裂原激活蛋白(MAP)激酶。大分子MAPK1(BMK1)是新近发现的一种MAPK，参与细胞的增殖、分化和存活。我们检测了醛固酮是否刺激BMK1介导的培养的大鼠主动脉平滑肌细胞(RASMCs)的增殖。用Western blotting和荧光标记方法检测盐皮质激素受体(MR)的表达和定位。蛋白印迹法检测ERK1/2和BMK1活性。用阿拉玛蓝比色法测定细胞增殖。醛固酮(0.1~100nmol/L)可剂量依赖性地激活RASMCs的BMK1，30min达高峰。为了阐明醛固酮诱导的BMK1激活是否是MR介导的现象，我们研究了选择性MR拮抗剂依普利酮对醛固酮诱导的BMK1激活的影响。依普利酮(0.1~10mU·mol/L)可剂量依赖性地抑制醛固酮诱导的RASMCs BMK1激活。醛固酮也能刺激RASMC的增殖，而依普利酮对此有抑制作用。由于放线菌酮不能抑制醛固酮诱导的BMK1的激活，故认为醛固酮介导的现象可归因于非基因组效应。BMK1上游调控因子显性负性MAPK/ERK激酶5(MEK5)可部分抑制醛固酮诱导的RASMC增殖，该作用可被MEK抑制剂PD98059几乎完全抑制。除了经典的类固醇活性外，由醛固酮引起的快速非基因组效应可能代表着高血压等血管疾病的另一种病因。
The nongenomic effects of aldosterone have been implicated in the pathogenesis of various cardiovascular diseases. Aldosterone-induced nongenomic effects are attributable in part to the activation of extracellular signal-regulated kinase 1/2 (ERK1/2), a classical mitogen-activated protein (MAP) kinase. Big MAP kinase 1 (BMK1), a newly identified MAP kinase, has been shown to be involved in cell proliferation, differentiation, and survival. We examined whether aldosterone stimulates BMK1-mediated proliferation of cultured rat aortic smooth muscle cells (RASMCs). Mineralocorticoid receptor (MR) expression and localization were evaluated by Western blotting analysis and fluorolabeling methods. ERK1/2 and BMK1 activities were measured by Western blotting analysis with the respective phosphospecific antibodies. Cell proliferation was determined by Alamar Blue colorimetric assay. Aldosterone (0.1 to 100 nmol/L) dose-dependently activated BMK1 in RASMCs, with a peak at 30 minutes. To clarify whether aldosterbne-induced BMK1 activation is an MR-mediated phenomenon, we examined the effect of eplerenone, a selective MR antagonist, on aldosterone-induced BMK1 activation. Eplerenone (0.1 to 10 mu mol/L) dose-dependently inhibited aldosterone-induced BMK1 activation in RASMCs. Aldosterone also stimulated RASMC proliferation, which was inhibited by eplerenone. Aldosterone-mediated phenomena were concluded to be attributable to a nongenomic effect because cycloheximide failed to inhibit aldosterone-induced BMK1 activation. Transfection of dominant-negative MAP kinase/ERK kinase 5 (MEK5), which is an upstream regulator of BMK1, partially inhibited aldosterone-induced RASMC proliferation, which was almost completely inhibited by MEK inhibitor PD98059. In addition to the classical steroid activity, rapid nongenomic effects induced by aldosterone may represent an alternative etiology for vascular diseases such as hypertension.