[The role of cytochrome P450 in nonalcoholic fatty liver induced by high-fat diet: a gene expression profile analysis].

Objective: To clarify the role of cytochrome P450 in nonalcoholic fatty liver disease (NAFLD) by RNA-Seq and bioinformatics analysis. Methods: A total of 20 male C57BL/6 mice were used. Ten mice were fed with high-fat diet (D12492, 60% kcal fat) for 16 weeks to establish a mouse model of NAFLD, and the other 10 mice were fed with low-fat diet (D12450B, 10% kcal fat) as control group. At the end of the experiment, the body weight, liver weight, and hepatic triglyceride (TG) content were measured. Meanwhile, HE staining and RNA-Seq analysis were performed for the liver tissues. The differentially expressed genes were screened out and subjected to bioinformatics analysis, including KEGG and GO BP enrichment analyses and interaction network analysis. Comparison of means between the two groups was made using t-test. Results: Compared with the control group, the mice in the model group were obviously obese, with significantly increased body weight (41.41 ± 6.01 g vs 28.78 ± 1.79 g, t = 6.04, P < 0.01) and liver weight (1.38 ± 0.30 g vs 1.08 ± 0.10 g, t = 2.89, P < 0.01). The mice in the model group showed obvious steatosis, accompanied by a small amount of inflammatory cell infiltration, but with no obvious fibrosis, according to the results of HE staining. In addition, the hepatic TG content in the model group was significantly increased compared with that in the control group (0.64 ± 0.01 mg/mg vs 0.29 ± 0.06 mg/mg, t = 10.11, P = 0.04). Compared with the control group, a total of 367 differentially expressed genes, including 211 down-regulated and 156 up-regulated ones, were identified in the model group according to the RNA-seq results. Meanwhile, 19 CYP450 subtypes, accounting for 5% of the differentially expressed genes, were identified, and CYP2E1, CYP2C70, CYP3A11, CYP3A25, CYP2D26, CYP4A10, CYP17A1, CYP2B10, and CYP2C38 were involved in oxidative stress, steroid hormone metabolism, fatty acid metabolism, arachidonic acid metabolism, and the PPAR signaling pathway. An interaction network was constructed with 30 nodes, and CYP2E1 and CYP2C70 were identified as key nodes. RT-PCR validation results showed that the expression changes of CYP450 subtypes and lipid metabolism-related genes were consistent with the findings of sequencing. Conclusion: The CYP450 family plays a vital role in the pathogenesis of fatty liver by regulating lipid metabolism-related pathways, including oxidative stress, arachidonic acid metabolism, steroid hormone metabolism , and fatty acid metabolism.目的： 用二代转录组测序（RNA-seq）技术，结合差异基因GO分析、KEGG富集分析，探讨细胞色素（CY）P450在高脂饮食诱导的小鼠非酒精性脂肪性肝（NAFLD）中的作用。 方法： 高脂饲料（D12492，60%脂肪热量）喂养C57BL/6J小鼠16周构建NAFLD模型，以低脂饲料（D12450B，10%脂肪热量）为对照。实验结束后检测体质量、肝质量及肝脏组织中甘油三酯含量，对肝组织行HE染色及RNA-Seq分析，对差异表达基因进行GO分析、KEGG分析及相互作用网络分析。两样本均数比较采用t检验。 结果： 与对照组相比，模型组小鼠明显肥胖，体质量和肝质量显著高于对照组[（41.41±6.01）g比（28.78±1.79）g，t = 6.04，P < 0.01]和[（1.38±0.30）g比（1.08±0.10）g，t = 2.89，P < 0.01]；HE染色可见模型组小鼠肝脏发生严重脂肪变性，伴少量炎症细胞浸润，但未见明显的纤维化，模型组肝脏甘油三酯含量显著增高[（0.64±0.01）mg/mg比（0.29±0.06）mg/mg，t = 10.11，P = 0.04]。RNA-seq结果显示高脂饮食导致367个基因差异表达，211个下调，156个上调，其中CYP450基因有19个，占差异表达基因的5%，其中CYP2E1、CYP2C70、CYP3A11、CYP3A25、CYP2D26、CYP4A10、CYP17A1、CYP2B10、CYP2C38等参与氧化应激、类固醇激素代谢、脂肪酸代谢、花生四烯酸代谢，以及过氧化物酶体增殖物激活受体信号通路等过程；相互作用网络分析预测发挥连接作用的基因有30个，CYP2E1、CYP2C70在其中发挥核心作用。RT-PCR方法对CYP450基因在组织中进行基因水平验证，实验结果与测序结果一致。 结论： CYP450通过参与氧化应激，脂肪酸代谢、花生四烯酸代谢，类固醇激素合成等多个途径影响脂质代谢，与非酒精性脂肪肝发病进程密切相关。.