A novel epigenetic mechanism unravels hsa-miR-148a-3p-mediated CYP2B6 downregulation in alcoholic hepatitis disease
A novel epigenetic mechanism unravels hsa-miR-148a-3p-mediated CYP2B6 downregulation in alcoholic hepatitis disease
复制标题
一种新的表观遗传机制揭示了酒精性肝炎疾病中 hsa-miR-148a-3p 介导的 CYP2B6 下调
DOI：
10.1016/j.bcp.2021.114582
复制
发表时间：
2021-05-01
影响因子：
5.8
通讯作者：
Yu, Dianke
中科院分区：
文献类型：
--
作者：
Luo, Jiao;Xie, Mengyue;Yu, Dianke
细胞色素P450（CYP）酶在药物转化中起着关键作用，酒精性肝炎（AH）是一种致命的酒精性肝病，其总CYP显著降低。miRNAs是一种内源性非编码小分子RNA，调控着许多重要的生物学过程。有关AH疾病中CYP的miRNA调节的知识有限。本文从GEO数据库中检索AH患者肝脏样本中关键CYP的变化，并对可能靶向调控异常的CYP转录本的miRNA进行计算机模拟预测，揭示了miRNA介导CYP在肝细胞中表达的新机制。9种miRNAs被预测调节CYP 1A 2、CYP 2A 6、CYP 2B 6、CYP 2C 8、CYP 2C 19、CYP 2 J2和CYP 3A 4，其中hsamiR-148 a-3 p被选择作为案例研究。生物化学和分子生物学证据表明，miR-148 a通过直接与3 ' UTR序列结合增加mRNA的稳定性来促进CYP 2B 6的表达，并且这种转录后正调控是AGO 1/2依赖性的。此外，荧光素酶报告基因测定和RNA二级结构分析表明，控制miR-148 a介导的CYP 2B 6上调的是无籽靶位点，而不是种子靶位点。此外，我们通过EMSA和染色质免疫沉淀实验确定HNF 4A为MIR-148 A的肝脏特异性转录因子。总之，乙醇通过HNF 4A调节下调肝细胞中的miR-148 a，最终降低CYP 2B 6表达。我们的发现将有助于理解AH患者的药物代谢失调，并强调了表观遗传调控的非传统机制。
Cytochrome P450 (CYP) enzymes play critical roles in drug transformation, and the total CYPs are markedly decreased in alcoholic hepatitis (AH), a fatal alcoholic liver disease. miRNAs are endogenous small noncoding RNAs that regulate many essential biological processes. Knowledge concerning miRNA regulation of CYPs in AH disease is limited. Here we presented the changes of key CYPs in liver samples of AH patients retrieved from GEO database, performed in silico prediction of miRNAs potentially targeting the dysregulated CYP transcripts, and deciphered a novel mechanism underlying miRNA mediated CYPs expression in liver cells. Nine miRNAs were predicted to regulate CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2J2, and CYP3A4, among which hsamiR-148a-3p was selected as a case study. Biochemical and molecular evidences demonstrated that miR-148a promoted CYP2B6 expression by increasing mRNA stability via directly binding to the 3 ' UTR sequence, and that this positive posttranscriptional regulation was AGO1/2-dependent. Further, luciferase reporter gene assay and RNA secondary structure analysis illustrated that the seedless target site, not the seed target site, controlled miR-148a-mediated CYP2B6 upregulation. Moreover, we identified HNF4A as a liver-specific transcription factor of MIR-148A through EMSA and chromatin immunoprecipitation experiments. In conclusion, ethanol downregulated miR-148a in hepatocytes through HNF4A regulation, which eventually decreased CYP2B6 expression. Our finding will benefit the understanding of dysregulated drug metabolism in AH patients and highlight an unconventional mechanism for epigenetic regulation of CYP gene expression.