Molecular Mechanism for Regulation of INS-1 Rat Insulinoma Cell Proliferation by Orexin-A / 中国医科大学学报

ABSTRACT

Objective To investigate the interference effects of orexin A on cell proliferation of the insulin?secreting beta?cell line(INS?1 cells) through the orexin receptor 1(OX1R)and the AKT/PKB signaling pathway. Methods INS?1 cells were exposed to different concentrations of orexin A in vitro,and treated with OX1R antagonist(SB334867),PI3K antagonist(wortmannin),or AKT antagonist(PF?04691502). The INS?1 cell proliferation and apoptosis,insulin secretion,OX1R protein activity and AKT phosphorylation level were determined. Results Orexin A(10-10 to 10-6 mol/L)stimulated the proliferation and activation of INS?1 cells,prevented apoptpsis,and increased insulin secretion. Additionally,AKT phosphorylation was stimulated by orexin A(10-10 to 10-6 mol/L). The OX1R antagonist SB334867(10-6 mol/L),the PI3K antagonist wortmannin (10-8 mol/L)and the AKT antagonist PF?04691502(10-6 mol/L)weakened the effects of orexin A. Conclusion Orexin A activated the AKT sig?naling pathway through the mediation of orexin A?OX1R,and promoted cell proliferation in INS?1 cells.