黄芪多糖通过激活AMPK减轻同型半胱氨酸对人血管内皮细胞的损伤

目的:探讨黄芪多糖(Astragalus polysaccharides,APS)能否减轻同型半胱氨酸(homocysteine,Hcy)对人血管内皮细胞的损伤及其可能的机制。方法:培养人脐静脉内皮细胞,分为正常对照组、APS组APS(200mg/L)处理24 h]、Hcy组Hcy(1 mmol/L)处理24 h]和Hcy+APS组Hcy(1 mmol/L)和APS(200 mg/L)共同处理24 h]。采用MTT法检测细胞活力,采用试剂盒法检测内皮细胞中乳酸脱氢酶(lactate dehydrogenase,LDH)和超氧化物歧化酶(superoxidase dismutase,SOD)活性及丙二醛(malondialdehyde,MDA)含量,采用RT-q PCR检测SOD1、过氧化氢酶(catalase,CAT)和NADPH氧化酶2(NADPH oxidase 2,NOX2)的mRNA表达,并采用Western blot检测腺苷酸活化蛋白激酶α(AMP-activated protein kinaseα,AMPKα)和磷酸化AMPKα(phosphorylated AMPKα,pAMPKα)的蛋白水平。结果:与对照组相比,Hcy组内皮细胞活力明显下降,LDH活性升高,细胞内MDA含量,SOD活性下降,SOD1和CAT的mRNA表达水平显著下降,而NOX2的mRNA表达水平明显升高(P0.05)。APS能够抑制Hcy引起的细胞活力下降、LDH活性升高及MDA含量增加;增加SOD活性,提高SOD1和CAT的mRNA表达水平,减少NOX2的mRNA表达水平(P0.05)。AMPK抑制剂Compound C则可以显著降低APS对Hcy引起的内皮细胞损伤的修复作用。结论:APS可通过活化AMPK调控细胞内氧化应激从而抑制Hcy对血管内皮细胞的损伤。

Astragalus polysaccharides attenuate endothelial cell injury caused by homocysteine via AMPK pathway

AIM:To investigate the protective effect of Astragalus polysaccharides (APS) on human umbilical vein endothelial cells (HUVECs) injured by homocysteine (Hcy) and its mechanism. METHODS:HUVECs cultured in vitro were divided into 4 groups:control group, APS groupAPS (200 mg/L) treatment for 24 h], Hcy groupHcy (1 mmol/L) treatment for 24 h], and Hcy+APS groupHcy (1 mmol/L) and APS (200 mg/L) co-treatment for 24 h]. The cell viability were measured by MTT assay. The activity of lactate dehydrogenase (LDH) and superoxidase dismutase (SOD), and the content of malondialdehyde (MDA) in HUVECs were detected by the commercial kits. The mRNA expression of SOD1, catalase (CAT) and NADPH oxidase 2 (NOX2) was detected by RT-qPCR. The protein levels of AMP-activated protein kinase α (AMPKα) and phosphorylated AMPKα (p-AMPKα) were determined by Western blot. RESULTS:Compared with control group, the cell viability, the activity of SOD, and the mRNA expression of SOD1 and CAT in the HUVECs were decreased, but the activity of LDH, the content of MDA, and the mRNA expression of NOX2 were increased significantly in Hcy group(P<0.05). APS inhibited the decrease in cell viability, and the increases in LDH acti-vity and MDA content induced by Hcy. APS increased SOD activity and the mRNA expression of SOD1 and CAT, but reduced the mRNA expression of NOX2. Compound C, an AMPK inhibitor, reduced the protective effect of APS on HUVECs injured by Hcy. CONCLUSION:APS protects HUVECs from Hcy-induced injury via AMPK signaling pathway to regulate intracellular oxidative stress.