非酒精性脂肪性肝炎C57BL/6小鼠模型构建与评价

Construction and Evaluation of a Mouse Model of Nonalcoholic Steatohepatitis in C57BL/6 Mice

摘要: 目的：采用MCD饲料喂养诱导小鼠非酒精性脂肪肝炎(NASH)模型，通过检测NASH相关指标来评价该模型的可行性。方法：将健康的C57BL/6小鼠采用随机分层方法将其分为对照组(饲养普通饲料，n = 6)和模型组(以MCD饲料干预，n = 6)，于第6周末将其处死。取肝脏组织称重，观察其形态变化，比较体质量及肝脏质量；肝组织分别进行苏木精–伊红(HE)染色以评估组织病理变化；油红O染色以观察脂质情况；Masson染色以观察纤维化程度；联酶免疫吸附实验(ELISA)检测肝脏炎性因子(TNF-α、IL-6)表达，检测炎症水平。结果：与对照组相比，模型组小鼠肝组织表面暗淡无光，呈黄褐色，质地粗糙易碎且弹性差，体重显著降低(P < 0.0001)，表明MCD诱导对小鼠的代谢状态产生了影响；通过HE染色观察，模型组小鼠肝细胞脂肪变性及炎性细胞浸润，表明MCD诱导能成功导致脂肪变性及肝细胞损伤；油红O染色显示，模型组小鼠肝组织出现大量红色脂滴，细胞内TG含量有所增加，表明MCD诱导能成功模拟肝细胞内脂质积聚；Masson染色显示模型组肝组织出现大范围蓝染胶原纤维，表明MCD诱导能成功导致轻度纤维化；模型组小鼠肝组织中TNF-α (P < 0.001)、IL-6 (P < 0.01)的含量均有所升高，表明MCD饲料成功诱导了炎症反应。结论：MCD饮食诱导下成功建立小鼠NASH模型。

Abstract: Objective: This study aimed to evaluate the feasibility of establishing a mouse model of non-alcoholic steatohepatitis (NASH) induced by a methionine-choline-deficient (MCD) diet through the detection of NASH-related indicators. Methods: Healthy C57BL/6 mice were randomly assigned to either a control group (fed a standard diet, n = 6) or a model group (fed an MCD diet, n = 6) using a stratified randomization method. At the end of the 6-week period, the mice were euthanized. Liver tissues were collected, weighed, and examined for morphological changes. Body weight and liver weight were compared between the two groups. Liver tissues were processed for hematoxylin-eosin (HE) staining to evaluate histopathological alterations, Oil Red O staining to visualize lipid accumulation, and Masson staining to assess the extent of fibrosis. Additionally, the expression levels of inflammatory cytokines (TNF-α and IL-6) in liver tissues were quantified using an enzyme-linked immunosorbent assay (ELISA) to determine the degree of inflammation. Results: Compared to the control group, the liver tissues of the model group mice appeared dull and yellowish-brown in color, with a rough, fragile texture and reduced elasticity. The body weight of the model group mice was significantly lower (P < 0.0001), indicating that the MCD diet affected the metabolic state of the mice. Histopathological examination using HE staining revealed hepatic steatosis and inflammatory cell infiltration in the liver tissues of the model group, demonstrating that the MCD diet successfully induced steatosis and hepatocyte injury. Oil Red O staining showed the presence of numerous red lipid droplets in the liver tissues of the model group, along with increased intracellular triglyceride (TG) content, indicating that the MCD diet effectively simulated lipid accumulation in hepatocytes. Masson staining revealed extensive blue-stained collagen fibers in the liver tissues of the model group, suggesting that the MCD diet successfully induced mild fibrosis. Furthermore, the levels of TNF-α (P < 0.001) and IL-6 (P < 0.01) in the liver tissues of the model group were significantly elevated, confirming that the MCD diet successfully triggered an inflammatory response. Conclusion: The NASH mouse model was successfully established through MCD diet induction.