Roles for insulin receptor, PI3-kinase, and Akt in insulin-signaling pathways related to production of nitric oxide in human vascular endothelial cells

Article

关键词: RAT ADIPOSE-CELLS;    PROTEIN-KINASE-B;    PHOSPHATIDYLINOSITOL 3-KINASE;    GENE-TRANSFER;    1-PHOSPHATIDYLINOSITOL 3-KINASE;    GLUCOSE-UPTAKE;    GROWTH-FACTOR;    TRANSLOCATION;    GLUT4;    ELECTROPORATION;   

DOI  :  10.1161/01.CIR.101.13.1539

来源: SCIE

【 摘 要 】

Background-Previously, we demonstrated that insulin stimulates production of nitric oxide (NO) in endothelial cells. However, specific insulin-signaling pathways mediating production of NO have not been elucidated. Methods and Results-We developed methods for transfection of human umbilical vein endothelial cells (HUVECs) and direct measurement of NO to begin defining insulin-signaling pathways related to NO production. HUVECs were cotransfected with enhanced Green Fluorescent Protein (eGFP) and another gene of interest. Transfection efficiencies >95% were obtained by selecting cells expressing eGFP. Overexpression of insulin receptors in HUVECs resulted in an approximate to 3-fold increase in production of NO in response to insulin. In contrast, HUVECs overexpressing a tyrosine kinase-deficient mutant insulin receptor had a dose-response curve similar to that of control cells. Overexpression of inhibitory mutants of either phosphatidylinositol 3-kinase (PI3K) or Akt resulted in nearly complete inhibition of insulin-stimulated production of NO. Overexpression of an inhibitory mutant of Rns had a much smaller effect. Conclusions-Receptor kinase activity is necessary to mediate production of NO through the insulin receptor. Both PI3K and Akt contribute importantly to this process, whereas the contribution of Ras is small.

【 授权许可】

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