Essential role of protein kinase G and decreased cytoplasmic Ca2+ levels in NO-induced inhibition of rat aortic smooth muscle cell motility.
Essential role of protein kinase G and decreased cytoplasmic Ca2+ levels in NO-induced inhibition of rat aortic smooth muscle cell motility.
复制标题
蛋白激酶 G 和细胞质 Ca2 水平降低在 NO 诱导的大鼠主动脉平滑肌细胞运动抑制中的重要作用。
DOI：
10.1152/ajpheart.01031.2004
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Hassid,Aviv
中科院分区：
文献类型：
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作者：
Zhuang,Daming;Ceacareanu,Alice-Corina;Ceacareanu,Bogdan;Hassid,Aviv
高胰岛素血症是血管疾病发展的主要危险因素。我们已经报道了胰岛素通过过氧化氢介导的机制增加血管平滑肌细胞的运动性，而一氧化氮（NO）通过cgmp介导的机制减弱胰岛素诱导的运动性。cGMP升高下游的事件尚未研究。我们的研究目的是验证一氧化氮和cGMP在培养的大鼠主动脉平滑肌细胞中的抗运动作用是通过PKG介导的，随后是细胞质Ca2+水平的降低和蛋白酪氨酸磷酸酶脯氨酸、谷氨酸、丝氨酸和苏氨酸活性的增加，从而抑制激动剂诱导的过氧化氢水平升高和细胞运动。用表达PKG-1α的腺病毒处理原代培养物模拟了NO诱导的胰岛素诱导的过氧化氢升高和细胞运动的抑制，而用药理学PKG抑制剂rp -8-溴-3 ',5 ' -环单磷硫酸盐（Rp-8-Br-cGMPS）处理恢复了被NO供体抑制的胰岛素刺激作用。用胰岛素治疗细胞不能增加细胞质Ca2+水平，而NO供体在存在或不存在胰岛素的情况下降低了细胞质Ca2+水平。Ca2+螯合剂BAPTA处理细胞模拟PKG和NO供体的作用，并增加PTP-PEST的活性。最后，PTP-PEST显性负等位基因处理逆转了BAPTA对细胞运动和过氧化氢升高的抑制作用。我们得出结论，no诱导的细胞运动抑制是通过pkg介导的基底细胞质Ca2+水平的降低发生的，随后PTP-PEST活性增加，导致过氧化氢水平降低和细胞运动降低。
Hyperinsulinemia is a major risk factor for the development of vascular disease. We have reported that insulin increases the motility of vascular smooth muscle cells via a hydrogen peroxide-mediated mechanism and that nitric oxide (NO) attenuates insulin-induced motility via a cGMP-mediated mechanism. Events downstream of cGMP elevation have not yet been investigated. The aim of our study was to test the hypothesis that antimotogenic effects of NO and cGMP in cultured rat aortic smooth muscle cells are mediated via PKG, followed by reduction of cytoplasmic Ca2+levels and increased protein tyrosine phosphatase-proline, glutamate, serine, and threonine activity, leading to suppression of agonist-induced elevation of hydrogen peroxide levels and cell motility. Treatment of primary cultures with adenovirus expressing PKG-1α mimicked NO-induced inhibition of insulin-elicited hydrogen peroxide elevation and cell motility, whereas treatment with the pharmacological PKG inhibitor Rp-8-bromo-3′,5′-cyclic monophosphorothioate (Rp-8-Br-cGMPS) rescued the stimulatory effects of insulin that were suppressed by NO donor. Treatment of cells with insulin failed to increase cytoplasmic Ca2+levels, whereas NO donor decreased cytoplasmic Ca2+levels in the presence or absence of insulin. Treatment of cells with the Ca2+chelator BAPTA mimicked the effects of PKG and the NO donor and increased the activity of PTP-PEST. Finally, treatment with a dominant negative allele of PTP-PEST reversed the inhibitory effect of BAPTA on cell motility and hydrogen peroxide elevation. We conclude that NO-induced inhibition of cell motility occurs via PKG-mediated reduction of basal cytoplasmic Ca2+levels, followed by increased PTP-PEST activity, leading to decreased hydrogen peroxide levels and reduced cell motility.