Farnesoid X receptor (FXR) activation induces the antioxidant protein metallothionein 1 expression in mouse liver
Farnesoid X receptor (FXR) activation induces the antioxidant protein metallothionein 1 expression in mouse liver
复制标题
法尼醇 X 受体 (FXR) 激活诱导小鼠肝脏中抗氧化蛋白金属硫蛋白 1 的表达
DOI：
10.1016/j.yexcr.2020.111949
复制
发表时间：
2020-05-01
影响因子：
3.7
通讯作者：
Zhang, Xiaoyan
中科院分区：
文献类型：
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作者：
Wang, Bing;Zhang, Haibo;Zhang, Xiaoyan
Farnesoid X受体（FXR）是一种代谢性核受体，可保护肝脏免受内源性和外源性损伤。金属硫蛋白（MTs）是一个低分子量的蛋白家族，参与金属稳态和肝脏氧化应激的调节。在本研究中，我们旨在探讨FXR对肝脏MT1表达的影响及其机制。用合成FXR配体GW4064或天然配体CDCA处理C57BL/6小鼠或原代培养小鼠肝细胞。通过rnas测序（RNA-seq）分析确定GW4064处理小鼠肝脏中的基因表达谱。采用Real-time PCR和Western blot检测GW4064和CDCA处理的小鼠肝脏和原代肝细胞中MT1等FXR靶基因的表达。用免疫组织化学方法检测GW4064处理小鼠肝脏中MT1的细胞和亚细胞位置。转染FXR小干扰rna （siRNA）使FXR沉默。荧光素酶报告基因和染色质免疫沉淀（ChIP）检测通过FXR证实MT1基因启动子活性的调控。RNA-seq分析显示，GW4064处理显著诱导小鼠肝脏MT1表达。与此一致的是，GW4064和CDCA上调了小鼠肝脏和培养肝细胞中MT1的表达。此外，腺病毒介导的FXR过表达显著增加，sirna介导的FXR沉默在培养的肝细胞中显著抑制MT1的表达。荧光素酶报告基因和ChIP实验进一步证实MT1基因受FXR的直接控制。总之，我们的研究结果表明，MT1是FXR的一个新的靶基因，可能有助于FXR在肝脏疾病中的抗氧化能力。
Farnesoid X receptor (FXR) is a metabolic nuclear receptor, which protects liver from many endogenous and exogenous injuries. Metallothioneins (MTs) belong to a low-molecular-weight protein family involved in metal homeostasis and the regulation of hepatic oxidative stress. In the present study, we aimed to investigate the effect of FXR on hepatic MT1 expression and the underlying mechanism. C57BL/6 mice or primary cultured mouse hepatocytes were treated with the synthetic FXR ligand GW4064 or natural ligand CDCA. RNASequencing (RNA-seq) analysis was performed to identify gene expression profile in the livers of mice treated with GW4064. Real-time PCR and Western blot were applied to determine the expression of MT1 and other FXR target genes in the livers of mice and primary hepatocytes treated with GW4064 and CDCA. Cellular and subcellular locations of MT1 in the livers of mice treated with GW4064 were examined using immunohistochemistry assay. FXR small interfering RNAs (siRNA) was transfected to silence FXR. Luciferase reporter and chromatin immunoprecipitation (ChIP) assays were utilized to confirm the regulation of MT1 gene promoter activity by FXR. RNA-seq analysis revealed that GW4064 treatment significantly induced MT1 expression in mouse liver. Consistently, MT1 expression in the hepatocytes of mouse livers and cultured hepatocytes was upregulated by GW4064 as well as CDCA. In addition, adenovirus-mediated overexpression of FXR markedly increased, while siRNA-mediated FXR silencing significantly suppressed MT1 expression in cultured hepatocytes. Luciferase reporter and ChIP assays further confirmed that the MT1 gene was under the direct control of FXR. Collectively, our findings demonstrate that MT1 is a novel target gene of FXR and may contribute to antioxidative capacity of FXR in liver diseases.