mTOR/Akt/FoxO3信号通路在人参皂苷Rg_1抗PC-12细胞OGD损伤的作用

Protective effect of ginsenoside Rg_1 again PC-12 cells in OGD injury through mTOR/Akt/FoxO3 signaling pathway

目的:研究人参皂苷Rg_1对PC-12细胞缺氧缺糖(oxygen-glucose deprivation,OGD)损伤的保护作用,并初步探讨与mTOR/Akt调控FoxO3核浆穿梭相关的可能的分子机制。方法:建立OGD损伤PC-12细胞模型,MTT法检测OGD对PC-12细胞存活率。人参皂苷Rg_110,20,40μmol·L^(-1)预处理PC-12细胞24 h,加OGD损伤,MTT检测细胞存活率,比色法检测乳酸脱氢酶(LDH)释放、超氧化物歧化酶(SOD)活力和丙二醛(MDA)含量。Western blot法检测mTOR,p-Akt^(ser473),p-Akt^(thr308),Akt,p-FoxO3,细胞核、细胞质FoxO3和总FoxO3蛋白表达。结果:OGD作用4~24 h显著抑制PC-12细胞增殖,呈时间依赖性。Rg_1(20,40μmol·L^(-1))预处理24 h可显著增加细胞存活率,减少LDH释放,增加SOD活力和降低MDA含量。Rg_1可抑制由OGD引起的mTOR,p-Akt^(ser473)表达降低。OGD 6 h可减少FoxO3磷酸化,并促进细胞质FoxO3进入细胞核;预处理Rg_1增加FoxO3磷酸化,促进FoxO3进入细胞质。提示Rg_1可经由调控mTOR/Akt/FoxO3信号通路抑制PC-12细胞损伤。结论:人参皂苷Rg_1可抑制OGD引起PC-12细胞损伤,作用机制可能与激活mTOR/Akt信号通路调控FoxO3核质穿梭密切相关。

Objective： To investigate the protective effect of ginsenoside Rgl on oxygen-glucose deprivation （OGD） in PC-12 cells, and preliminarily discuss the potential molecular mechanism of mTOR/Akt/FoxO3 signaling pathway. Method： The OGD PC-12 cell model was established. The cell viability was measured by MTr assay. After the pretreatment with Rg1 with the concentration of 10, 20, 40 μmol · L-1 for 24 h, the cell viability was observed. Lactate dehydrogenase （LDH） release, superoxide dismutase （SOD） ac- tivity and malondialdehyde（MDA） level were detected by colorimetry assay, mTOR, p-Akt^ser473 , p-Akt^thrs308 , Akt, p-FoxO3, FoxO3 in cytoplasm and nucleus, and total FoxO3 protein expression were detected by Western blot assay. Result： OGD could significantly in- hibit cell proliferation in 4-24 h in a time-dependent manner. After pretreatment for 24 h, Rgl （20, 40 μmol · L- 1 ） could notably ele- vate the cell viability and SOD viability and reduce the LDH release and MDA content. Besides, Rg1 also inhibited OGD-induced mTOR and p-Akt^ser473 decreases. After treatment for 6 h, OGD could reduce FoxO3 phosphorylation and promote FoxO3 in cytoplasm. This data suggested that Rg1 could protect PC-12 cell injury through mTOR/p-Akt/FoxO3 signaling pathway. Conclusion： Ginsenoside Rg1 could attenuate OGD-induced PC-12 cell injury. Its action mechanism may be closely related to activation of mTOR/p-Akt/FoxO3 signaling pathway.