Study about the elucidation of hepatocarcinogenesis mechanism km fatty liver and preventive strategies based on pathogenic considerations

在本研究中，我们使用FLS小鼠(n=48)。FLS小鼠发展为自发性脂肪肝，慢性无肥胖。肝脏肿瘤在1岁以后发展。将FLS小鼠分为3组：1组单纯饲喂对照饲料(CA-1)，2组饲喂含有乳酸菌的饲料，3组饲喂含有酪酸梭菌的对照饲料。10个月龄时，所有小鼠的肝脏都有明显的脂肪沉积，没有纤维化。12月龄时，第1组8只小鼠中有2只发生肝肿瘤，第2组和第3组均有1只发生肝癌。高效液相色谱法测定粪便中短链脂肪酸含量，第3组小鼠粪便中丁酸钠浓度升高。10月龄小鼠肝组织免疫组织化学分析显示，第1组小鼠氧化应激标志物4-HNE较第3组显著升高。反之，Western印迹分析显示，转录因子NF-KB在第3组小鼠肝脏中的蛋白表达增加。第三组小鼠肝脏中c-jun(Ser73)的磷酸化程度也明显高于第三组小鼠。最后，Western blotting结果显示，第三组小鼠肝脏中p21WAF1的蛋白表达也增加，这些结果表明氧化应激在FLS小鼠肝脏疾病的发展中起着关键作用。口服酪酸梭菌对FLS小鼠肝肿瘤的发生有保护作用。

We used FLS mice (n=48) in this study. FLS mouse develops spontaneously fatty liver chronically without obesity. Liver tumors develop after age of 1 year. The FLS mice were subdivided into three groups : group 1 received control diet (CA-1) alone, group 2 received diet containing lactobacillus, and group 3 received control diet containing clostridium butyricum that produce butyric acid in a bowel after oral intake.At age 10 month, all mice showed significant fatty deposition in the liver without fibrosis. At age 12 month, 2 out of 8 mice in group 1 developed liver tumor, whereas 1 out of 8 mice developed liver tumor in both group 2 and 3. Measurement of short chain fatty acid in the feces by HPLC revealed that concentration of sodium butyrate increased in the mice of group 3.Immunohistochemical analysis of the liver of 10-month-old LPS mice showed that 4-HNE, a marker of oxidative stress, remarkably increased in group 1 mice compared with those in group 3 mice. On the contrary, the protein expression of transcription factor NF-KB increased in the liver of group 3 mice by the Western blot analysis. Phosphorylation of c-jun (Ser 73) was also observed in the liver of mice in group 3. Finally, protein expression of p21 WAF1 also increased in the liver of group 3 mice by the Western blot.These results indicate that oxidative stress takes a crucial role in the progression of liver disease in FLS mice. Oral intake of clostridium butyricum may protect the development of liver tumor in FLS mice.