人ATP7B基因对Wilson病动物模型LEC大鼠暴发性肝炎的治疗

TRANSGENIC RESCUE FROM FULMINANT HEPATITIS IN LEC RAT BY INTRODUCING HUMAN ATP7B cDNA

目的 探讨人ATP7B基因对Wilson病动物模型LEC大鼠暴发性肝炎的治疗效果。 方法 将构建的 7.1kb含有鸡 β肌动蛋白启动子的人正常ATP7BcDNA ,经显微注射法导入人Wilson病动物模型LEC(long EvansCinnamon)大鼠受精卵 ,建立转基因功能恢复大鼠模型。以Westernbolt检测人ATP7B在转基因大鼠肝内的表达 ,用同窝无转基因大鼠及正常野生型LEA大鼠作对照 ,对 6～ 16周龄的转基因大鼠的血清AST、ALT和总胆红素水平进行连续测定 ,同时取 13周龄转基因大鼠的肝组织进行病理学和组织化学分析。 结果 人ATP7B基因在转基因大鼠的肝组织中获得正确和完整的表达 :12周龄前后 ,与同窝无转基因大鼠相比 ,转基因大鼠的血清AST、ALT和总胆红素水平明显降低 ,肝组织的炎性病变显著减轻 ,肝细胞内铜的蓄积减少 ;至 16周龄 ,转基因大鼠的临床表型未见异常 ,存活率达 10 0 %。说明人ATP7B的导入 ,成功地抑制了Wilson病动物模型LEC大鼠的暴发性肝炎的发生。结论 Wilson病肝炎的发生与ATP7B基因功能缺陷引起的铜蓄积有直接关系。基因转移有可能是一种有效的治疗Wilson病的方法。

Objective To investigate the possibility of affecting transgenic rescue for Wilson disease using the human ATP7B transgenic LEC rat.Methods The 7.1kb transgene constructed with human ATP7B cDNA and chicken β-actin promoter was introduced into the fertilized oocytes of LEC rats, an animal model of Wilson disease, by microinjection. The expressions of human ATP7B protein in the transgenic rats were detected by Western blot. The plasma AST and ALT activities, and the total bilirubin levels in transgenic rats were measured continuously from 6 to 16 weeks using non-transgenic rats and LEA rat as controls. The pathological and histochemistry changes in the liver of the transgenic rats at 13 weeks were analyzed. Results The intact and correct product derived from human ATP7B was confirmed in the liver of transgenic rats. At the age around 12 weeks, the plasma AST and ALT activities, and the total bilirubin levels in transgenic rats were significantly decreased, while the inflammatory reation in the liver of transgenic rats was much mild as compared with that of non-transgenic rats, and the granules of stained copper were less in the hepatocytes of transgenic rats. By the age of 16 weeks, the transgenic rats were phenotypically normal, and the survival rate was 100%. These data showed that the LEC rats were successfully rescued from fulminant hepatitis after introducing of human ATP7B gene. Conclusion The hepatitis in Wilson disease is directly related to the toxicity of excessive accumulated copper, which attributed to the functional deficiency of the ATP7B. Gene transfer probably is the effective method for the therapy of Wilson disease.