Hydrogen peroxide generated during cellular insulin stimulation is integral to activation of the distal insulin signaling cascade in 3T3-L1 adipocytes
Hydrogen peroxide generated during cellular insulin stimulation is integral to activation of the distal insulin signaling cascade in 3T3-L1 adipocytes
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DOI：
10.1074/jbc.m105061200
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发表时间：
2001-12-28
影响因子：
4.8
通讯作者：
Goldstein, BJ
中科院分区：
文献类型：
--
作者：
Mahadev, K;Wu, XD;Goldstein, BJ
在多种细胞类型中，胰岛素刺激引起H2O2的快速产生，H2O2引起蛋白酪氨酸磷酸酶的氧化抑制，并在早期胰岛素作用级联中增强蛋白酪氨酸磷酸化(Mahadev， K., Zilbering, a ., Zhu， L., and Goldstein， B. J. (2001) J. Biol。化学。276,21938-21942)。在目前的工作中，我们探索了胰岛素诱导的11,02生成对下游胰岛素信号传导的潜在作用，使用二苯乙烯(I)PI)，一种细胞NADPH氧化酶抑制剂，阻断胰岛素刺激的细胞H2O2生成。DPI完全抑制胰岛素对磷脂酰肌醇（PI） t激酶活性的激活，并使胰岛素诱导的丝氨酸激酶Alit活性降低高达49%；当将H2O2添加回DPI预处理的细胞时，这些活性恢复。有趣的是，H2O2诱导的Akt活化完全是由上游刺激PI t激酶活性介导的，因为用PI 3'-激酶抑制剂wortmannin或LY294002处理3T3-L1脂肪细胞完全阻断了外源H2O2对Alit的激活。用DPI防止氧化剂生成也阻断了胰岛素刺激的葡萄糖摄取和GLUT4向质膜的转运，进一步证明了氧化信号在远端胰岛素信号级联调控中的作用。最后，与其他生长因子（如血小板衍生生长因子）产生H2O2的细胞机制相反，我们还发现胰岛素刺激的细胞产生H2O2可能通过一种独特的途径发生，不依赖于细胞PI 3'-激酶活性。总的来说，这些数据提供了对胰岛素依赖性H2O2生成的生理作用的深入了解，它不仅参与调节早期胰岛素信号级联中的酪氨酸磷酸化事件，而且对下游胰岛素信号的调节也有重要影响，包括PI 3'-激酶、Akt的激活，以及最终响应胰岛素的细胞葡萄糖转运。
In a variety of cell types, insulin stimulation elicits the rapid production of H2O2, which causes the oxidative inhibition of protein-tyrosine phosphatases and enhances the tyrosine phosphorylation of proteins in the early insulin action cascade (Mahadev, K., Zilbering, A., Zhu, L., and Goldstein, B. J. (2001) J. Biol. Chem. 276, 21938-21942). In the present work, we explored the potential role of insulin-induced 11,02 generation on downstream insulin signaling using diphenyleneiodonium (I)PI), an inhibitor of cellular NADPH oxidase that blocks insulin-stimulated cellular H2O2 production. DPI completely inhibited the activation of phosphatidylinositol (PI) T-kinase activity by insulin and reduced the insulin-induced activation of the serine kinase Alit by up to 49%; these activities were restored when H2O2 was added back to cells that had been pretreated with DPI. Interestingly, the H2O2-induced activation of Akt was entirely mediated by upstream stimulation of PI T-kinase activity, since treatment of 3T3-L1 adipocytes with the PI 3'-kinase inhibitors wortmannin or LY294002 completely blocked the subsequent activation of Alit by exogenous H2O2. Preventing oxidant generation with DPI also blocked insulin-stimulated glucose uptake and GLUT4 translocation to the plasma membrane, providing further evidence for an oxidant signal in the regulation of the distal insulin-signaling cascade. Finally, in contrast to the cellular mechanism of H2O2 generation by other growth factors, such as platelet-derived growth factor, we also found that insulin-stimulated cellular production of H2O2 may occur through a unique pathway, independent of cellular PI 3'-kinase activity. Overall, these data provide insight into the physiological role of insulin-dependent H2O2 generation, which is not only involved in the regulation of tyrosine phosphorylation events in the early insulin signaling cascade but also has important effects on the regulation of downstream insulin signaling, involving the activation of PI 3'-kinase, Akt, and ultimately cellular glucose transport in response to insulin.