蓝莓对肝纤维化大鼠肝组织自噬相关蛋白LC3和Beclin1表达的影响

Effect of blueberry on microtubule-associated protein 1 light chain 3 protein and Beclin1 expression in liver tissue of rats with hepatic fibrosis

目的:观察蓝莓对免疫性肝纤维化大鼠肝组织微管相关蛋白轻链3(microtubule-associated protein 1 light chain 3,LC3)及Beclin1表达的影响.方法:60只健康♂SD大鼠随机分为正常对照组、模型组、蓝莓原浆高剂量组、蓝莓原浆中剂量组、蓝莓原浆低剂量组及复方鳖甲软肝片组.除正常对照组外,其余各组均采用腹腔注射无菌猪血清复制大鼠肝纤维化模型.造模同时各蓝莓组给予不同浓度蓝莓原浆(0.25 m L/100 g、0.5 m L/100 g、1.0 m L/100 g)灌胃,复方鳖甲软肝片组用复方鳖甲软肝片灌胃(0.054 g/100 g),1次/d.12wk处死大鼠,测定血清谷丙转氨酶(alanine transaminase,ALT)、谷草转氨酶(aspartate transaminase,AST)含量,行肝组织病理学检查;Western blot检测LC3-Ⅱ、Beclin1、Ⅰ型胶原(ColⅠ)的蛋白水平;实时定量PCR(realtime quantitative PCR,q RT-PCR)检测LC3-Ⅱ、Beclin1的m RNA水平.结果:各组大鼠血清ALT、AST水平差异无统计学意义(均P>0.05).与正常对照组比较,模型组肝纤维化程度明显(P<0.05),LC3-Ⅱ、Beclin1的m RNA及蛋白表达、ColⅠ的蛋白表达明显增高(均P<0.01).与模型组比较,蓝莓原浆高、中剂量组肝纤维化程度明显减轻(P<0.05),胶原表达减少;LC3-Ⅱ、Beclin1的m RNA、蛋白表达及ColⅠ的蛋白表达明显降低(均P<0.01).结论:猪血清所致的大鼠免疫性肝纤维化中自噬相关蛋白LC3-Ⅱ、Beclin1升高,蓝莓对大鼠免疫性肝纤维化的干预作用可能与下调LC3和Beclin1的基因及蛋白表达,进而抑制自噬有关.

AIM： To investigate the effect of blueberry on microtubule-associated protein 1 light chain 3（LC3） protein and Beclin1 expression in liver tissue of rats with hepatic fibrosis. METHODS： Sixty male SD rats were randomly divided into a normal control group, a hepatic fibrosis model group, high-, medium-, and lowdose blueberry treatment groups, and a Fufang Biejia Ruangan tablet treatment group. Except the normal control group, hepatic fibrosis was induced in other groups by intraperitoneal injection of porcine serum. Simultaneously, rats in blueberry treatment groups and Fufang Biejia Ruangan tablet treatment group were, respectively, given oral blueberry juice at a dose of 0.25 m L/100g, 0.5 m L/100g, and 1.0 m L/100g, and Fufang Biejia Ruangan tablet（0.054g/100g） daily. All rats were killed at the end of the 12 th week. Serum alanine aminotransferase（ALT） and aspartate aminotransferase（AST） were measured. Pathological changes in the hepatic tissue were evaluated by hematoxylineosin（HE） and Masson staining. The expression of LC3-Ⅱ and Beclin1 was examined by Western blot and q RT-PCR. The expression of collagen Ⅰ（ColⅠ） were examined by Western blot.RESULTS： Serum levels of ALT and AST had no significant differences in all the groups（P 0.05）. Compared with the normal control group, the expression of LC3-Ⅱ, Beclin1 and Col Ⅰ were significantly higher（P 0.01） in the hepatic fibrosis model group, andthe pathological stages of hepatic fibrosis were significantly aggravated. Compared with the hepatic fibrosis model group, the, expressions of LC3-Ⅱ, Beclin1 and Col Ⅰ w e r e s i g n i f i c a n t l y l o w e r（ P 0.01）, and the pathological stages of hepatic fibrosis were significantly reduced in the high- and medium-dose blueberry treatment groups（P 0.05）. CONCLUSION： The expression of LC3-Ⅱ and Beclin1 increases in rats with hepatic fibrosis. The inhibitory effects of blueberry on hepatic fibrosis may be achieved by lowering the expression of LC3-Ⅱ and Beclin1 and then inhibiting autophagy.