May Stephanie, Müller Miryam, Livingstone Callum R, Skalka George L, Walsh Peter J, Nixon Colin, Hedley Ann, Shaw Robin, Clark William, Vande Voorde Johan, Officer-Jones Leah, Ballantyne Fiona, Powley Ian R, Drake Thomas M, Kiourtis Christos, Keith Andrew, Rocha Ana Sofia, Tardito Saverio, Sumpton David, Le Quesne John, Bushell Martin, Sansom Owen J, Bird Thomas G
Cancer Research UK Beatson Institute, Glasgow, G61 1BD, UK.
Cancer Research UK Beatson Institute, Glasgow, G61 1BD, UK; School of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow, G61 1QH, UK.
J Hepatol. 2023 May;78(5):1028-1036. doi: 10.1016/j.jhep.2023.01.009. Epub 2023 Jan 23.
BACKGROUND & AIMS: Mouse models of lineage tracing have helped to describe the important subpopulations of hepatocytes responsible for liver regeneration. However, conflicting results have been obtained from different models. Herein, we aimed to reconcile these conflicting reports by repeating a key lineage-tracing study from pericentral hepatocytes and characterising this Axin2CreERT2 model in detail.
We performed detailed characterisation of the labelled population in the Axin2CreERT2 model. We lineage traced this cell population, quantifying the labelled population over 1 year and performed in-depth phenotypic comparisons, including transcriptomics, metabolomics and analysis of proteins through immunohistochemistry, of Axin2CreERT2 mice to WT counterparts.
We found that after careful definition of a baseline population, there are marked differences in labelling between male and female mice. Upon induced lineage tracing there was no expansion of the labelled hepatocyte population in Axin2CreERT2 mice. We found substantial evidence of disrupted homeostasis in Axin2CreERT2 mice. Offspring are born with sub-Mendelian ratios and adult mice have perturbations of hepatic Wnt/β-catenin signalling and related metabolomic disturbance.
We find no evidence of predominant expansion of the pericentral hepatocyte population during liver homeostatic regeneration. Our data highlight the importance of detailed preclinical model characterisation and the pitfalls which may occur when comparing across sexes and backgrounds of mice and the effects of genetic insertion into native loci.
Understanding the source of cells which regenerate the liver is crucial to harness their potential to regrow injured livers. Herein, we show that cells which were previously thought to repopulate the liver play only a limited role in physiological regeneration. Our data helps to reconcile differing conclusions drawn from results from a number of prior studies and highlights methodological challenges which are relevant to preclinical models more generally.
谱系追踪小鼠模型有助于描述负责肝脏再生的重要肝细胞亚群。然而，不同模型得到了相互矛盾的结果。在此，我们旨在通过重复一项来自中央周围肝细胞的关键谱系追踪研究，并详细表征该Axin2CreERT2模型，来调和这些相互矛盾的报告。
我们对Axin2CreERT2模型中标记的细胞群体进行了详细表征。我们对该细胞群体进行谱系追踪，在1年多的时间里对标记群体进行定量，并对Axin2CreERT2小鼠与野生型对照小鼠进行深入的表型比较，包括转录组学、代谢组学以及通过免疫组织化学分析蛋白质。
我们发现，在仔细定义基线群体后，雄性和雌性小鼠在标记方面存在显著差异。在诱导谱系追踪后，Axin2CreERT2小鼠中标记的肝细胞群体没有扩增。我们发现了大量证据表明Axin2CreERT2小鼠的稳态受到破坏。后代出生时的比例低于孟德尔比例，成年小鼠的肝脏Wnt/β-连环蛋白信号传导受到干扰以及相关代谢组紊乱。
我们没有发现证据表明在肝脏稳态再生过程中中央周围肝细胞群体有主要的扩增。我们的数据强调了详细的临床前模型表征的重要性，以及在比较不同性别和背景的小鼠以及基因插入天然基因座的影响时可能出现的陷阱。
了解肝脏再生细胞的来源对于利用它们再生受损肝脏的潜力至关重要。在此，我们表明先前被认为可重新填充肝脏的细胞在生理再生中仅起有限作用。我们的数据有助于调和先前一些研究结果得出的不同结论，并突出了更普遍适用于临床前模型的方法学挑战。
