Investigation of the involvement of oxidative stress in metabolic syndrome and the development of new anti-oxidants

我们使用体内和体外策略研究了氧化应激在代谢综合征中的可能参与。我们研究了血管紧张素II （Ang II）对胰岛素诱导的血管平滑肌细胞（VSMC）葡萄糖摄取的影响及其细胞内机制。Ang II或氧化应激抑制胰岛素诱导的葡萄糖摄取，在VSMC中，ERK抑制剂可逆转这一作用，而JNK抑制剂则不能逆转。慢性肾系血管增生性肾小球肾炎（GN）大鼠模型采用非肾切除和抗thy -1抗体注射，在GN第28和56天观察肾小球BMK1的活化。在培养的大鼠系膜细胞中，Ang II和氧化应激诱导BMK1激活，提示Ang II和氧化应激参与炎症诱导的代谢综合征。我们还发现H2O2在培养的大鼠VSMC中以时间和浓度依赖性的方式激活BMK1。Src酪氨酸激酶的激活也与BMK1的激活平行。我们利用siRNA转染技术建立了BMK1敲低VSMC的实验模型。此外，我们的研究结果还表明，在BMK1 siRNA转染的抑制BMK1表达的VSMC中加入H2O2可增加细胞死亡。这些发现提示BMK1可能在保护细胞免受氧化应激诱导的凋亡中发挥重要作用，这一过程是由src介导的信号通路介导的。c-Src和BMK1可能是代谢综合征临床治疗的潜在靶点。

We investigated the possible involvement of oxidative stress in metabolic syndrome using in vivo and in vitro strategies. We examined the effect of angiotensin II (Ang II) on insulin-induced glucose uptake and its intracellular mechanisms in cultured vascular smooth muscle cells (VSMC). Ang II or oxidative stress inhibited insulin-induced glucose uptake, which was reversed by an ERK inhibitor but not by a JNK inhibitor in VSMC. In the chronic mesangioproliferative glomerulonephritis (GN) rat model using uninephrectomy and anti-Thy-1 antibody injection, activation of BMK1 was observed in the glomeruli at day 28 and 56 of GN. In the cultured rat mesangial cells, Ang II and oxidative stress induced BMK1 activation, suggesting that Ang II and oxidative stress involves in an inflammation-induced metabolic syndrome. We also found that BMK1 was activated by H2O2 in a time- and concentration-dependent manner in cultured rat VSMC. The activation of Src tyrosine kinase was also observed which was parallel with the BMK1 activation. We established an experimental model of BMK1 knock downed VSMC using siRNA transfection technology. Furthermore, our results also showed that cell death was increased when H2O2 was added into the BMK1 siRNA transfected VSMC in which BMK1 expression was inhibited. From these findings, it was suggested that BMK1 may play an essential role in protecting cells from oxidative stress-induced apoptosis, which is mediated by Src-mediated signaling pathway. c-Src and BMK1 may be possible targets for the treatment of metabolic syndrome clinically.