A human-like bile acid pool induced by deletion of hepatic Cyp2c70 modulates effects of FXR activation in mice[S]
A human-like bile acid pool induced by deletion of hepatic Cyp2c70 modulates effects of FXR activation in mice[S]
复制标题
DOI：
10.1194/jlr.ra119000243
复制
发表时间：
2020-03-01
影响因子：
6.5
通讯作者：
Kuipers, Folkert
中科院分区：
文献类型：
--
作者：
de Boer, Jan Freark;Verkade, Esther;Kuipers, Folkert
胆汁酸（BA）促进脂溶性营养素的肠道吸收，并通过法尼醇X受体（FXR）和武田G蛋白偶联受体5调节各种代谢途径。这些受体是胆汁淤积性和代谢性疾病的治疗靶点。然而，人类和小鼠之间BA代谢的差异使临床前数据的翻译复杂化。细胞色素P450家族2亚家族c多肽70（CYP 2C 70）是近年来发现的一种能催化啮齿动物特异性胞壁胆酸（MCAs）形成的多肽。通过CRISPR/Cas9介导的体细胞基因组编辑，我们生成了急性肝脏Cyp 2c 70敲除小鼠模型（Cyp 2c 70（ako）），以阐明CYP 2C 70在体内BA代谢中的作用，并评估其活性是否调节药理学FXR激活对胆固醇稳态的影响。在Cyp 2c 70（ako）小鼠中，鹅去氧胆酸（CDCA）以β MCA为代价增加，导致更疏水的类人BA池。示踪剂研究表明，在体内，CYP 2C 70主要通过CDCA的连续6 β-羟基化和C7-差向异构化催化β MCA的形成，生成α MCA作为中间代谢物。在生理学上，与WT小鼠相比，Cyp 2c 70（ako）小鼠中的人源化BA组合物减弱了响应于FXR活化的粪便胆固醇处置的刺激，这主要是由于经肠胆固醇排泄的刺激减少。因此，成年小鼠肝脏Cyp 2c 70的缺失转化为人样BA池组成，并影响对药理学FXR活化的反应。这种Cyp 2c 70（ako）小鼠模型可能是一个有用的工具，为未来的研究BA信号和代谢，告知人类疾病的发展和治疗。
Bile acids (BAs) facilitate intestinal absorption of lipid-soluble nutrients and modulate various metabolic pathways through the farnesoid X receptor (FXR) and Takeda G-protein-coupled receptor 5. These receptors are targets for therapy in cholestatic and metabolic diseases. However, dissimilarities in BA metabolism between humans and mice complicate translation of preclinical data. Cytochrome P450 family 2 subfamily c polypeptide 70 (CYP2C70) was recently proposed to catalyze the formation of rodent-specific muricholic acids (MCAs). With CRISPR/Cas9-mediated somatic genome editing, we generated an acute hepatic Cyp2c70 knockout mouse model (Cyp2c70(ako)) to clarify the role of CYP2C70 in BA metabolism in vivo and evaluate whether its activity modulates effects of pharmacologic FXR activation on cholesterol homeostasis. In Cyp2c70(ako) mice, chenodeoxycholic acid (CDCA) increased at the expense of beta MCA, resulting in a more hydrophobic human-like BA pool. Tracer studies demonstrated that, in vivo, CYP2C70 catalyzes the formation of beta MCA primarily by sequential 6 beta-hydroxylation and C7-epimerization of CDCA, generating alpha MCA as an intermediate metabolite. Physiologically, the humanized BA composition in Cyp2c70(ako) mice blunted the stimulation of fecal cholesterol disposal in response to FXR activation compared with WT mice, predominantly due to reduced stimulation of transintestinal cholesterol excretion. Thus, deletion of hepatic Cyp2c70 in adult mice translates into a human-like BA pool composition and impacts the response to pharmacologic FXR activation. This Cyp2c70(ako) mouse model may be a useful tool for future studies of BA signaling and metabolism that informs human disease development and treatment.