[Effect of rosiglitazone on NO and eNOS via PI3K/PKB signal pathways in cultured human umbilical vein endothelial cells].

OBJECTIVE: To observe the effect of rosiglitazone on the production of nitric oxide (NO) and the expression of phosphatidylinositol 3-kinase (PI3K)/protein kinase B(PKB) /the endothelial nitric oxide synthase (eNOS) in cultured human umbilical vein endothelial cells(HUVECs), and to investigate the mechanism of signal transduction of rosiglitazone in improving the endothelial function.

METHODS: HUVECs were treated with various concentrations of rosiglitazone. The NO level was measured using Griess Reaction in cell culture supernatants; the expressions of PI3K-,PKB- and eNOS mRNA were measured using RT-PCR; and the expressions of PKB, eNOS, and phosphorylation of PKB-Ser473, eNOS-Ser1177 were measured using Western Blot.

RESULTS: Rosiglitazone increased the endothelial NO production in a dose- and time-dependent manner in cultured HUVECs, and also increased the expression of PI3K mRNA and the phosphorylation of PKB-Ser473 and eNOS-Ser1177 in a concentration-dependent manner, with no alteration in the expression of PKB and eNOS in cultured HUVECs. N(w)-nitro-L- arginine methyl ester (L-NAME, eNOS synthase inhibitor) blocked the rosiglitazone-induced NO formation; LY294002(a PI3K inhibitor) prevented the NO production; and the phosphorylation of eNOS and PKB was induced by rosiglitazone.

CONCLUSION: Treatment with rosiglitazone can increase the NO prouducion and improve the endothelial function through up-regulating the PI3K/PKB/eNOS signal pathways in cultured HUVECs.