慢性丙型肝炎合并脂肪肝患者Sirt1和固醇调节元件结合蛋白表达及意义

Expression and clinical significance of Sirt1 and sterol-regulatory element binding proteins in hepatitis C virus infected patients with fatty liver

目的探讨丙型肝炎病毒(HCV)感染合并不同程度的肝脏脂肪变患者Sirt1和SREBP表达及其临床意义。方法收集2015年7月至2017年6月于湖州市第一人民医院肝病科就诊患者共140例,其中80例丙型肝炎患者(包括20例无脂肪肝的单纯丙型肝炎患者,20例丙型肝炎合并轻度脂肪肝患者,20例丙型肝炎合并中度脂肪肝患者及20例丙型肝炎合并重度脂肪肝患者);60例单纯脂肪肝患者(包括20例单纯轻度脂肪肝患者,20例单纯中度脂肪肝患者,20例单纯重度脂肪肝患者)。选择20例健康查体者为正常对照组。分别检测入组患者性别、年龄及HCV RNA水平(入组丙型肝炎患者抗体均为阳性),收集患者外周血样本,通过real-time PCR及Western blot检测Sirt1和SREBP表达水平。结果与单纯丙型肝炎患者相比,丙型肝炎合并轻度脂肪肝患者Sirt1水平差异无统计学意义(t=0.344、P=0.732),丙型肝炎合并中度、重度脂肪肝患者Sirt1水平下降:mRNA水平分别下调0.724倍(t=4.265、P<0.001)和0.540倍(t=2.489、P=0.013);蛋白水平分别下调0.69倍(t=4.857、P<0.001)和0.51倍(t=10.523、P=0.002),差异均有统计学意义。与单纯丙型肝炎患者相比,丙型肝炎合并轻度、中度、重度脂肪肝患者SREBP-1c水平上升:mRNA水平分别上调1.132倍(t=-3.924、P<0.001)、1.424倍(t=-4.300、P<0.001)和1.663倍(t=-3.758、P=0.001);蛋白水平分别上调1.49倍(t=-9.323、P<0.001)、1.65倍(t=-14.992、P<0.001)和1.79倍(t=-15.847、P<0.001),差异均有统计学意义。单纯丙型肝炎患者、丙型肝炎合并轻度、中度、重度脂肪肝患者间SREBP-2表达差异无统计学意义(P>0.05)。与单纯轻度脂肪肝患者比较,丙型肝炎合并轻度脂肪肝患者Sirt1表达水平差异无统计学意义(t=0.344、P=0.732)。与单纯中、重度脂肪肝患者相比,丙型肝炎合并中、重度脂肪肝患者Sirt1表达水平显著下降:mRNA水平分别下调0.682倍(t=2.987、P=0.010)和0.521倍(t=5.366、P<0.001);蛋白水平分别下调0.800倍(t=2.801、P=0.016)和0.635倍(t=7.891、P<0.001),差异均有统计学意义。与单纯轻度、中度、重度脂肪肝患者相比,丙型肝炎合并轻度、中度、重度脂肪肝患者SREBP-1c表达水平显著升高:mRNA水平分别上调1.428倍(t=-15.943、P<0.001)、1.592倍(t=-9.135、P=0.004)和1.521倍(t=-9.138、P<0.001);蛋白水平分别上调1.622倍(t=-7.960、P=0.010)、1.749倍(t=-2.196、P=0.012)和1.803倍(t=-8.942、P=0.045),差异均有统计学意义。结论丙型肝炎病毒感染可通过抑制Sirt1及上调SREBP-1c表达而影响肝脏脂肪变。

Objective To investigate the expression and clinical significance of Sirt1 and sterol-regulatory element binding proteins(SREBP)in hepatitis C patients with different degrees of fatty liver.Methods From July 2015 to June 2017,a total of 140 patients with hepatitis C were enrolled in the Department of Hepatology,the First People’s Hospital of Huzhou City,including 80 patients with hepatitis C(20 patients with simple hepatitis C without fatty liver,20 patients with HCV infected and mild fatty liver,20 patients with HCV infected and moderate fatty liver and 20 patients with HCV infected and severe fatty liver).There were 60 cases of fatty liver without HCV infection(20 cases of mild fatty liver,20 cases of moderate fatty liver and 20 cases of severe fatty liver).While 20 healthy people were selected as the normal control group.The sex,age and HCV RNA load(All the patients with hepatitis C were with positive anti-HCV)of the patients were detected,respectively.The peripheral blood samples were collected and the expression of Sirt1 and SREBP were detected by real-time PCR and Western blot.Results The levels of Sirt1 in patients with moderate and severe fatty liver were significantly lower than those in patients with hepatitis C:the levels of mRNA decreased by 0.724 times(t=4.265,P<0.001)and 0.540 times(t=2.489,P=0.013),respectively.The protein levels decreased by 0.69 times(t=4.857,P<0.001)and 0.51 times(t=10.523,P=0.002),respectively.There was no significant differences of Sirt1 expression between patients with mild fatty liver and HCV infected patients without mild fatty liver(t=0.344、P=0.732).The levels of SREBP-1c in HCV infected patients with mild,moderate and severe liver steatosis were higher than those in HCV infected patients without liver steatosis:the level of mRNA increased by 1.132 times(t=-3.924,P<0.001),1.424 times(t=-4.300,P<0.001),and 1.663 times(t=-3.758,P=0.001),respectively.Protein levels increased by 1.49 times(t=-9.323,P<0.001)and 1.65 times(t=-14.992,P<0.001)and 1.79 times(t=-15.847,P<0.001),respectively,with significant differences.There was no significant difference in SREBP-2 expression among HCV infected patients with mild,moderate and severe liver steatosis and HCV infected patients without liver steatosis(all P>0.05).In moderate and severe liver steatosis patients,compared with those without HCV infection,the expression of Sirt1 in patients with HCV infection decreased significantly:the level of mRNA decreased by 0.682 times(t=2.987,P=0.010)and 0.521 times(t=5.366,P<0.001),respectively.The protein levels decreased by 0.800 times(t=2.801,P=0.016)and 0.635 times(t=7.891,P<0.001),respectively,with significant differences.There was no significant difference of Sirt1 expression between mild fatty liver patients with HCV infection and those without HCV infection(t=0.344,P=0.732).In patients with mild,moderate and severe fatty liver,the expression of SREBP-1c in patients with HCV infection was significantly higher than that in patients without HCV infection.The level of mRNA increased by 1.428 times(t=-15.943,P<0.001),1.592 times(t=-9.135,P=0.004)and 1.521 times(t=-9.138,P<0.001),respectively.Protein levels increased by 1.622 times(t=-7.960,P=0.010,1.749 times(t=-2.196,P=0.012)and 1.803 times(t=-8.942,P=0.045),respectively,all with significant differences.Conclusion Hepatitis C virus infection could affect fatty liver by inhibiting Sirt1 expression and upregulating SREBP-1c expression.