The Mechnisms Of PI3K/AKT Signaling Pathway In ARC Protects Cells From Oxidative Injury

PI3K/AKT signaling pathway as a pro-survival signaling pathway, activation of the signaling pathway may protect cells against external stimuli in order to maintain the homeostasis. ARC(apoptosis repressor with a caspase recruitment domain) is the only known factor in its antagonism of both extrinsic(death receptor) and intrinsic(mitochondrial/ER) apoptosis pathways. While ARC expression is, for the most part, limited to terminal differentiated or cancer cells, it engages pro-survival signaling pathways common to non-myogenic, non-neurogenic human cells. At present, the mechanism of signal transduction of ARC exerts its protective effect remains unclear. Whether ARC exerted the biological effects was mediated by PI3K/AKT signaling pathway have not been reported before. The oxidative injury model established by different concentrations of H2O2 was used in primary chicken embryonic cardimyocytes, Hela and 293 T cells. ARC was subcloned into P-IRES2-EGFP, then the P-IRES2-ARC-EGFP plasmid was transfected into chicken embryonic cardimyocytes, Hela and 293 T cells. CCK-8 and PI staining were used to assess cell viability in order to demonstrate whether overexpression of ARC can protect the cell from oxidative injury. PI3 K, AKT-1 and P53 mRNA of the cells were detected by Real-Time PCR. Phosphorlated AKT, ARC and P53 protein were detected by Western blot. The special PI3 K inhibitor LY294002 treatment was used to explore the effect of ARC protects cells from oxidative injury was mediated by PI3K/AKT signaling pathway? The results showed that: PI3 K and AKT mRNA and phosphorlated AKT protein of chicken embryonic cardimyocytes, Hela cells induced by oxidative injury were highly expressed; but the phosphorlated AKT protein expression was unchanged in 293 T cells. The cell viability was significantly reduced in the treatment of LY294002. Overexpression of ARC protected Hela and 293 T cells, but not chicken embryonic cardimyocytes from oxidative injury, and the survival effect was independent of PI3K/AKT signaling pathway in Hela cells. The upregulation of P53 protein in 293 T cells under oxidative injury model in a time and dose dependent manner and ARC maintained 293 T cell viability in this situation. Based on the above conclusions, ARC protein or PI3K/AKT may provide a protective effect in the oxidative injury. ARC exerted the biological effect was not dependent on the activation of PI3K/AKT signaling pathway. Overexpression of ARC against oxidative damage may be due to endogenous ARC exerts anti-apoptotic function to inhibit endogenous apoptosis pathway initiated by P53.