【摘要】 目的探讨甜菜碱对脂肪变性HepG2细胞同型半胱氨酸(Hcy)水平、S腺苷蛋氨酸/S腺苷同型半胱氨酸(SAM/SAH)比值及脂代谢相关基因mRNA表达的影响。方法 60 mg/L油酸作用24 h诱导非酒精性脂肪变性HepG2细胞模型,分别按脂肪变性模型组、2.5、5、10 mmol/L甜菜碱组进行干预,同时设空白对照组,每组设3个复孔。各组细胞培养24 h后油红O-苏木素染色观察细胞脂滴形成情况,酶法测定甘油三酯(TG)浓度,高效液相色谱法(HPLC)测定Hcy浓度和SAM/SAH比值,RT-PCR检测MTP、APOB及DGAT2 mRNA的表达。结果与空白对照组比较,脂肪变性模型组的培养基中Hcy浓度上升(P<0.05);而甜菜碱各剂量组与空白对照组比较则差异均无统计学意义(均P>0.05)。与空白对照组比较,脂肪变性模型组的细胞内和培养基中TG浓度上升(均P<0.01);细胞内的SAM/SAH比值(P<0.05)、APOB的mRNA水平(P<0.01)均下降。与脂肪变性模型组的比较,2.5和10 mmol/L甜菜碱组细胞内TG浓度均有所增加(均P<0.05),5 mmol/L甜菜碱组培养基中TG浓度有所增加(P<0.01);10 mmol/L甜菜碱组的SAM/SAH比值明显上升(P<0.01);5、10 mmol/L甜菜碱组的APOB mRNA水平明显上升(均P<0.01);甜菜碱各剂量组中DAGT2的mRNA表达水平均有所上升(均P<0.05)。结论甜菜碱能降低脂肪变性HepG2细胞培养基Hcy的浓度,增高细胞内SAM/SAH比值,增加APOB的mRNA表达,可能提高细胞脂质清除能力,但同时增加了DGAT2 mRNA的表达,可能促进TG合成。更多还原

【Abstract】 Objective To observe the effects of betaine on the Hcy concentration,SAM/SAH ratio,and the mRNA expression of lipid metabolism related genes in steatotic hepatocytes.Methods A hepatocyte steatosis model was established using 60 mg / L oleic acid and HepG2 cells.Steatosis HepG2 cells were cultured in medium containing 0,2.5,5,and 10 mmol / L betaine for 24 h,respectively.The control group was cultured in regular medium containing no oleic acid and betaine.There were 3 subunits of every group.Lipid droplets in hepatocytes were observed after oil red O-hematoxylin staining.TG concentration was determined by enzymic method.Hcy level and SAM / SAH ratio were detected by HPLC while the expression of APOB,MTP,and DGAT2 mRNA were detected by RT-PCR.Results Compared with the control group,the model cells had higher Hcy in the medium(P < 0.05),and higher TG was observed in both cells and medium(P < 0.01).But the cellular SAM / SAH(P < 0.05) and APOB mRNA expression(P <0.01) was lower.Compared with the model group,the 2.5 and 10 mmol/L betaine groups had higher TG in cells(all P < 0.05),while the 5 mmol / L betaine group had higher TG in medium(P < 0.01).The SAM / SAH ratio in 10 mmol / L betaine group and the APOB mRNA expression in 5 and 10 mmol / L betaine groups were increased compared with the model cells(all P < 0.01).The DGAT2 mRNA expression was higher in betaine groups than both the control group and model group(all P < 0.05).Conclusion Betaine can decrease Hcy concentration in the steatotic hepatocytes’medium and increase SAM / SAH ratio in steatotic hepatocytes.Betaine enhanced TG excretion by increasing the APOB mRNA expression.Simultaneously,betaine increased the DGAT2 mRNA expression,which might increase the synthesis of TG.更多还原