BACKGROUND Compounds in clinical development for nonalcoholic steatohepatitis (NASH) improve liver histopathology in diet-induced obese mouse models of biopsy-confirmed NASH. Since the biopsy section used for histopathological evaluation represents only < 1% of the whole mouse liver, we evaluated how well biopsy-based quantitative image analyses correlate to stereology-based whole-liver quantitative changes upon drug treatment. METHODS Male leptin-deficient Lepob/Lepob mice were fed the Amylin liver NASH (AMLN) diet for 16 weeks before stratification into treatment groups using a biopsy-based evaluation of type I collagen αI (col1a1) levels. Mice were treated for 8 weeks with either vehicle (PO, QD), liraglutide (0.4 mg/kg, SC, QD), elafibranor (30 mg/kg, PO, QD) or INT-767 (10 mg/kg, PO, QD). Terminal quantitative histological assessment of liver lipid (hematoxylin-eosin staining), inflammation (galectin-3 immunohistochemistry (IHC); gal-3), and fibrosis (col1a1 IHC) was performed on terminal liver biopsies and compared with stereologically sampled serial sections spanning the medial, left and right lateral lobe of the liver. RESULTS The distribution of liver lipid and fibrosis was markedly consistent across lobes, whereas inflammation showed some variability. While INT-767 and liraglutide significantly reduced total liver weight by 20 and 48%, respectively, elafibranor tended to exacerbate hepatomegaly in Lepob/Lepob-NASH mice. All three compounds markedly reduced biopsy-based relative liver lipid content. Elafibranor and INT-767 significantly reduced biopsy-based relative gal-3 levels (P < 0.001), whereas INT-767 and liraglutide tended to reduce relative col1a1 levels. When changes in liver weight was accounted for, both INT-767 and liraglutide significantly reduced biopsy-based total col1a1 content. Although minor differences in absolute and relative liver lipid, inflammation and fibrosis levels were observed across lobes, the interpretation of drug-induced effects were consistent with biopsy-based conclusions. Notably, the incorporation of changes in total liver mass revealed that liraglutide's efficacy reached statistical significances for all analyzed parameters. CONCLUSIONS In conclusion, in-depth analyses of liver homogeneity demonstrated that drug-induced improvement in liver biopsy-assessed histopathology is representative for overall liver effects assessed using stereology. Importantly, these findings reveal how changes in whole-liver mass should be considered to provide a deeper understanding of apparent drug treatment efficacy in preclinical NASH studies.

中文翻译：

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在饮食诱导的活检证实的NASH肥胖小鼠模型中，以活检为基础的药物作用的有效性。

背景技术在非酒精性脂肪性肝炎（NASH）的临床开发中，化合物可改善经活检证实的饮食引起的肥胖小鼠模型的肝脏组织病理学。由于用于组织病理学评估的活检部分仅占整个小鼠肝脏的<1％，因此我们评估了基于活检的定量图像分析与药物治疗后基于立体学的全肝定量变化的相关性。方法使用基于活检的I型胶原αI（col1a1）水平分层，将雄性瘦素缺陷型Lepob / Lepob小鼠饲喂Amylin肝脏NASH（AMLN）饮食，然后分层为治疗组，持续16周。用运载体（PO，QD），利拉鲁肽（0.4 mg / kg，SC，QD），弹性纤维蛋白（30 mg / kg，PO，QD）或INT-767（10 mg / kg，PO， QD）。末期肝活检的终末定量组织学评估为肝脂质（苏木精-伊红染色），炎症（半乳凝素3免疫组化（IHC）； gal-3）和纤维化（col1a1 IHC），并与跨越该组织的体视取样连续切片进行比较肝脏的内侧，左侧和右侧外侧叶。结果肝叶间的脂质和纤维化分布明显一致，而炎症表现出一定的变异性。尽管INT-767和利拉鲁肽分别显着降低了20％和48％的总肝脏重量，但是elafibranor倾向于加剧Lepob / Lepob-NASH小鼠的肝肿大。所有这三种化合物均显着降低了基于活检的相对肝脂质含量。Elafibranor和INT-767显着降低了基于活检的相对gal-3水平（P <0.001），而INT-767和利拉鲁肽则倾​​向于降低相对应的col1a1水平。当考虑到肝脏重量的变化时，INT-767和利拉鲁肽均显着降低了基于活检的总col1a1含量。尽管在整个肺叶中观察到了绝对和相对肝脏脂质，炎症和纤维化水平的微小差异，但对药物诱导作用的解释与基于活检的结论一致。值得注意的是，合并总肝脏质量的变化表明，利拉鲁肽的功效对所有分析参数均达到统计学意义。结论总之，对肝同质性的深入分析表明，药物诱导的肝活检评估的组织病理学改善代表了使用立体学评估的总体肝效应。重要的，