S-腺苷蛋氨酸对活化人肝星状细胞增殖和凋亡的影响

背景:肝星状细胞(HSCs)的活化是肝纤维化发生的中心环节。S-腺苷蛋氨酸(SAM)是机体最重要的甲基供体,既往研究表明SAM具有一定的抗纤维化作用,能抑制HSCs的活化。目的:观察SAM对活化人肝星状细胞株LX-2增殖、凋亡的作用及其相关机制。方法:用不同浓度SAM培养LX-2细胞24 h,采用CCK-8法检测SAM对LX-2细胞增殖的影响,流式细胞术检测细胞周期和凋亡率,实时定量PCR法检测cyclin D1 mRNA表达,蛋白质印迹法检测α-SMA蛋白表达。结果:与对照组相比,3.0~8.0 mmol/L SAM能抑制LX-2细胞增殖,并呈剂量依赖性(P0.05);2.0、4.0 mmol/L组G1/G0期细胞比例显著降低(P0.05),S期细胞比例显著升高(P0.05);4.0、8.0 mmol/L组早期凋亡率和总体凋亡率显著升高(P0.05);2.0、4.0 mmol/L组cyclin D1 mRNA表达显著升高(P0.05);1.0、2.0、4.0 mmol/L组α-SMA蛋白表达显著降低(P0.05)。结论:SAM能抑制LX-2细胞增殖,其机制可能通过上调cyclin D1的表达而使细胞周期阻滞于S期;同时,SAM能诱导LX-2细胞的凋亡,并下调α-SMA的表达。

Effect of S-adenosylmethionine on Proliferation and Apoptosis of Activated Human Hepatic Stellate Cells

Background：Activation of hepatic stellate cells （HSCs） is the key step of liver fibrosis.S-adenosylmethionine （SAM） is the most important methyl donor.Previous studies have demonstrated that SAM has an anti-fibrosis effect and inhibits the activation of HSCs.Aims：To study the effect and relevant mechanism of SAM on proliferation and apoptosis of activated human HSCs line LX-2.Methods：Human HSCs LX-2 were cultured with different concentrations of SAM for 24 hours.The proliferation was detected by CCK-8 assay.Cell cycle distribution and apoptosis rate were analyzed by flow cytometry.mRNA expression of cyclin D1 was determined by real-time quantitative PCR,and protein expression of α-SMA was detected by Western blotting.Results：Compared with controls,the proliferation of LX-2 cells was inhibited by 3.0-8.0 mmol/L SAM with a dose-dependent manner （P 〈 0.05） ; the cell ratio of G1/G0 phase in 2.0 and 4.0 mmol/L SAM groups was significantly decreased （P 〈 0.05）,and cell ratio of S phase was significantly increased （P 〈 0.05） ; early cell apoptosis rates and total cell apoptosis rates induced by 4.0 and 8.0 mmol/L SAM were remarkably increased （P 〈 0.05） ;mRNA expression of cyclin D1 was evidently up-regulated in 2.0 and 4.0 mmol/L SAM groups （P 〈 0.05） ; protein expression of α-SMA in 1.0,2.0 and 4.0 mmol/L SAM groups was significantly reduced （P 〈 0.05）.Conclusions：SAM inhibits the proliferation of LX-2 cells probably via up regulating cyclin D1 expression to arrest the cell cycle at S phase;meanwhile,SAM induces apoptosis of LX-2 cells and decreases the expression of α-SMA.