褪黑素抑制肝星状细胞增殖的机制研究

目的 通过转化生长因子-β1(TGF-β1)激活肝星状细胞系(HSC-T6),探讨褪黑素对活化的肝星状细胞系HSC-T6的抑制作用及相关机制.方法 肝星状细胞被分为5组,分别为:对照组、模型组和3个不同剂量实验组,培养24h贴壁后换用无血清培养基,除对照组外均加入TGF-β1,在实验组加入不同浓度的褪黑素,培养48 h后,通过MTF实验检测褪黑素对肝星状细胞增殖的影响,通过细胞免疫组化方法检测褪黑素对肝星状细胞中Smad蛋白表达的影响.结果 与模型组相比,实验组中肝星状细胞的增殖明显被抑制(P＜0.05);TGF-β1能明显刺激肝星状细胞中Smad2/3和p-Smad2/3的表达(P＜0.叭),与模型组比较,实验组可以明显抑制Smad2/3和p-Smad2/3的表达(P＜0.05).结论 褪黑素可显著抑制肝星状细胞的增殖,其作用机制可能与抑制TGF-β1/ Smad信号通路相关.

The mechanism of melatonin attenuates activation of hepatic stellate cells

Objective To investigate the inhibitory effect of melatonin on TGF-β1-stimulated HSC-T6 cells and its underling mechanism.Methods The HSC-T6 cells were divided into five groups:control group,model group and three experimental groups.After being cultured for 24 h,they were replaced with FBS-free medium and treated with transforming growth factor-β1 (TGF-β1,5 ng/ml) excepted the control group,and melatonin was added immediately with different concentrations (1 nmol/L,1 μmol/L,0.1 mmol/L) in three experimental groups.After drugs incubation for 48 h,MTT assay was performed to assess the cell proliferation,immunocytochemistry were used to assess the expression levels of Smad2/3,p-Smad2/3.Results Melatonin could significantly inhibited cells proliferation simulating with TGF-β1 (P ＜ 0.05).The expression of Smad2/3 and p-Smad2/3 in TGF-β1-treated group were dramatically elevated compared to the control group(P ＜ 0.01).After being added with different concentrations of melatonin,the expression of Smad2/3 and p-Smad2/3 were strongly attenuated compared with the model group (P ＜ 0.05).Conclusion Melatonin significantly mitigates HSCs'activation,which might be related to TGF-β1/Smad signaling pathway.