己酮可可碱调节微RNA-122和过氧化物酶体增殖物激活受体α减轻酒精性肝炎大鼠肝损伤

Pentoxifylline reduces liver injury by regulating microRNA-122 and peroxisome proliferator-activated receptor-α expressions in alcoholic hepatitis rats

目的探讨己酮可可碱(PTX)对大鼠酒精性肝炎(AH)的治疗作用及其可能的机制。方法将30只Wistar雄性大鼠随机分为空白对照组(对照组)、AH模型组(模型组)、PTX组,每组各10只。模型组和PTX组采用乙醇阶梯灌胃的方式造模,对照组给予等体积的0.9%氯化钠溶液灌胃;从第9周起PTX组加用PTX 9 mg/(kg·d)灌胃,对照组和模型组则给予等体积的0.9%氯化钠溶液灌胃,共造模12周。造模结束后观察大鼠的一般情况,测定其体重、肝重、肝指数,检测血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、γ-谷氨酰转肽酶(GGT)和白蛋白水平,采用H-E染色对比各组大鼠肝脏组织病理学状态,实时PCR检测大鼠肝组织微RNA(miRNA)-122的转录水平,Western印迹法测定大鼠肝组织过氧化物酶体增殖物激活受体α(PPAR-α)蛋白质表达情况。结果①模型组和PTX组大鼠体重均显著低于对照组(P值均<0.01),PTX组大鼠体重显著高于模型组(P<0.01)。②模型组和PTX组大鼠肝重、肝指数均显著高于对照组(P值均<0.01),PTX组大鼠肝重、肝指数均显著低于模型组(P值均<0.01)。③模型组和PTX组的血清ALT、AST、GGT水平均高于对照组(P值均<0.05),白蛋白水平均显著低于对照组(P值均<0.05);而PTX组的血清ALT、AST、GGT水平均显著低于模型组(P值均<0.05),白蛋白水平显著高于模型组(P<0.05)。④模型组和PTX组均存在不同程度的脂肪变性和炎性细胞浸润,但PTX组脂肪变性和炎性细胞浸润程度较模型组有不同程度的减轻。⑤模型组和PTX组的miRNA-122表达均较对照组显著上调(P值分别为<0.01、0.05),PTX组miRNA-122表达显著低于模型组(P<0.01)。⑥模型组和PTX组PPAR-α表达均显著低于对照组(P值均<0.01),PTX组肝组织PPAR-α蛋白质相对表达量显著高于模型组(P<0.01)。结论 PTX可能是通过下调miRNA-122和上调其靶基因PPAR-α的表达对AH大鼠肝损伤产生一定的治疗作用。

Objective To investigate the therapeutic effect of pentoxifylline(PTX) on alcoholic hepatitis(AH) in rats and its possible mechanism. Methods Thirty Wistar male rats were randomly divided into blank control group, AH model group, and PTX group(n=10). AH model was constructed by alcohol intragastric administration in model group and PTX group for 12 weeks, and the equal volume of normal saline was given to blank control group. In the 9 th week, PTX 9 mg/(kg·d) was added until 12 weeks in PTX group, and the equal volume of normal saline was given to control group and model group. After modeling, the general conditions of rats were observed, and the body weight, hepatic weight, liver index as well as alanine transaminase(ALT), aspartate transaminase(AST), γ-Glutamyl transpeptidase(GGT) and albumin(Alb) in the serum were determined. H-E staining was conducted to compare the pathological status of liver tissue in rats of each group. Real-time polymerase chain reaction(PCR) was used to detect the transcription level of microRNA-122(miRNA-122)in liver tissue. Western Blotting was used to detect the protein expression of peroxisome proliferators-activated receptor alpha(PPAR-α). Results Compared with those in control group, the body weight of rats in model group and PTX group decreased significantly(both P<0.01);the body weight in PTX group was significantly higher than that in model group(P<0.01). The liver weight and liver index in model group and PTX group were significantly higher than those in control group(all P<0.01), and these two parameters in PTX group were significantly lower than those in model group(both P<0.01). Compared with those in control group, ALT, AST and GGT detected in model group and PTX group were significantly increased, while Alb were significantly decreased(all P<0.05). Compared with those in model group, ALT, AST and GGT detected in PTX group all decreased, while Alb value was increased(all P<0.05). Adipose degeneration and inflammatory cell infiltration were found in model group and PTX group, but they were more severe in model group as compared with PTX group. Compared with that in control group, the expression of miRNA-122 in model group and PTX group was significantly increased(P<0.01, P<0.05). The expression of miRNA-122 in PTX group was significantly lower than that in model group(P<0.01). PPAR-α expressions in model group and PTX group were significantly lower than that in control group(both P<0.01). PPAR-α expression in PTX group was significantly higher than that in model group(P<0.01). Conclusion PTX has a therapeutic effect on AH rats, which may be achieved by decreasing the expression of miRNA-122 and increasing the expression of its target gene PPAR-α.