BACKGROUND The prevalence of autoimmune hepatitis (AIH) is increasing, and its early clinical diagnosis is difficult. The pathogenesis of AIH remains unclear, and AIH-related studies are largely limited because of lack of suitable mouse models. METHODS To obtain a good tool for research on AIH, we first established an improved immune-mediated mouse model that can mimic the pathological process of AIH as in the human body, through repeated injections of human cytochrome P450 2D6 (CYP2D6) plasmid. Next, a proteomic analysis based on isobaric tag (IBT) technology was performed to detect the differentially expressed proteins (DEPs), and related biological functions and pathways in the plasma of AIH and normal mice. Finally, we performed enzyme-linked immunosorbent assay (ELISA) to further confirm the most abundant DEP in the plasma of patients with AIH. RESULTS Autoantibodies and the characteristic pathology of AIH were observed in our mouse model. Inflammatory infiltration also increased in the livers of AIH mice over time and plateaued by day 42 post the first injection. Chronic hepatitis was most severe on day 35 with the development of fibrosis as well, and the plasma of AIH mice were collected for proteomic analysis. A total of 176 DEPs were found in this experiment, of which 148 DEPs were up-regulated and 28 DEPs were down-regulated. Thirty significant Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways (P < 0.05) were detected. Arginine biosynthesis was found to be the most significant pathway involved in the AIH process. During the Gene Ontology (GO) analysis, most DEPs were found to be involved in the binding, cellular, and metabolic processes. Using ELISA, the most overexpressed DEP, serum amyloid A 1 (SAA1), was confirmed to be increased specifically in the plasma of patients with AIH compared to other chronic hepatitis. Different plasma levels of SAA1 were also found related to different grades of inflammation and stages of fibrosis in the liver of patients with AIH. CONCLUSIONS Our study is the first to describe the proteomics analysis of a true sense of AIH mouse model, which is beneficial for a better understanding of AIH pathogenesis and identifying potential biomarkers for its clinical diagnosis.

中文翻译：

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改良AIH小鼠模型中自身免疫性肝炎的血浆蛋白质组学分析。

背景技术自身免疫性肝炎（AIH）的患病率正在增加，并且其早期临床诊断很困难。AIH的发病机制仍不清楚，由于缺乏合适的小鼠模型，与AIH相关的研究在很大程度上受到限制。方法为了获得研究AIH的良好工具，我们首先建立了改良的免疫介导的小鼠模型，该模型可以通过反复注射人细胞色素P450 2D6（CYP2D6）质粒来模拟AIH在人体中的病理过程。接下来，基于等压标签（IBT）技术的蛋白质组分析进行了检测，以检测AIH和正常小鼠血浆中的差异表达蛋白（DEP）以及相关的生物学功能和途径。最后，我们进行了酶联免疫吸附试验（ELISA），以进一步确认AIH患者血浆中最丰富的DEP。结果在我们的小鼠模型中观察到了自身抗体和AIH的特征性病理。随着时间的流逝，AIH小鼠肝脏中的炎症浸润也增加，并在首次注射后第42天达到稳定。随着纤维化的发展，慢性肝炎在第35天也最严重，并收集AIH小鼠的血浆进行蛋白质组学分析。在该实验中共发现176个DEP，其中148个DEP被上调，而28个DEP被下调。检测到三十种重要的《京都基因与基因组百科全书》（KEGG）途径（P <0.05）。发现精氨酸的生物合成是参与AIH过程的最重要途径。在基因本体论（GO）分析过程中，发现大多数DEP参与结合，细胞和代谢过程。使用ELISA，与其他慢性肝炎相比，证实过表达最多的DEP，即血清淀粉样蛋白A 1（SAA1）在AIH患者的血浆中特异性升高。还发现不同血浆水平的SAA1与AIH患者肝脏中不同程度的炎症和纤维化阶段有关。结论我们的研究首次描述了对AIH小鼠模型的真实意义的蛋白质组学分析，这有助于更好地了解AIH的发病机理并为临床诊断确定潜在的生物标记物。与其他慢性肝炎相比，已证实在AIH患者的血浆中血清淀粉样蛋白A 1（SAA1）特异性升高。还发现不同血浆水平的SAA1与AIH患者肝脏中不同程度的炎症和纤维化阶段有关。结论我们的研究首次描述了对AIH小鼠模型的真实意义的蛋白质组学分析，这有助于更好地了解AIH的发病机理并为临床诊断确定潜在的生物标记物。与其他慢性肝炎相比，已证实在AIH患者的血浆中血清淀粉样蛋白A 1（SAA1）特异性升高。还发现不同血浆水平的SAA1与AIH患者肝脏中不同程度的炎症和纤维化阶段有关。结论我们的研究首次描述了对AIH小鼠模型的真实意义的蛋白质组学分析，这有助于更好地了解AIH的发病机理并为临床诊断确定潜在的生物标记物。