The role of lncRNAs in P450-mediated drug metabolism and drug-induced liver injury

摘要 该项目的目的是确定HNF 1a-AS 1的长链非编码RNA（lncRNA）的作用， HNF 4a-AS 1对细胞色素P450基因表达的调控药物代谢CYP 酶负责60-70%药物的治疗结果。了解所有关键因素， 调节β-内酰胺酶的表达对于预测药物治疗的结果是至关重要的。 肝细胞核因子1a（HNF 1a）、4a（HNF 4a）、胆固醇X受体的转录因子（TF） (PXR)而组成性雄烷受体（CAR）是其关键因素。在绑定到他们的响应后 转录因子通过改变组蛋白修饰状态促进转录调控 主要的表观遗传机制。剩下的问题是TF如何触发 组蛋白修饰的改变以促进调节β 2受体表达。lncRNA可能是 关键部件。越来越多的证据表明，染色体上TF旁的反义lncRNA 位置参与TF在基因表达调节中的功能。我们确定了两 lncRNA位于HNF 1a和HNF 4a的TF旁边，即HNF 1a-AS 1和HNF 4a-AS 1。几 需要解决根本性的挑战问题。(1)HNF 1a-AS 1和HNF 4a-AS 1是否 在动态过程中维持肝脏P450酶稳态的两个关键因素， 药物诱导，通过增强HNF 1a-AS 1或抑制HNF 4a-AS 1的转录 P450基因表达的调控(2)HNF 1a-AS 1和HNF 4a-AS 1是否是两个关键因素 在药物性肝损伤（DILI）的敏感性和随后的肝再生过程中的作用？ (3)HNF 1a-AS 1和HNF 4a-AS 1如何直接或间接参与P450基因表达的调控 通过改变组蛋白修饰来间接调节PXR或CAR？这些 这些基本问题对于深入理解调控的分子机制至关重要， CYP介导的药物代谢和DILI。在过去五年中，我们确定了 药物代谢中的lncRNA我们最近取得的进展使我们处于一个适当的地位， 这些基本问题的答案。我们已经制定了一个全面的计划来解决这些问题。 在未来五年内，体外和体内模型都面临挑战。完成后 建议的研究，我们希望提供答案，以解决挑战性的问题。拟议 这项工作将阐明lncRNA的表观遗传调控机制， 在暴露于药物后，在正反馈和负反馈回路中代谢β-内酰胺酶表达。的 这项工作将确定lncRNA在P450介导的药物代谢和易感性中的作用 到DILI。所产生的知识将有助于确定预测治疗效果的新的关键因素 和DILI。

ABSTRACT The aim of the project is to determine the roles of long non-coding RNAs (lncRNAs) of HNF1a-AS1 and HNF4a-AS1 in the regulation of cytochrome P450 (CYP) gene expression. Drug-metabolizing CYP enzymes are responsible for therapeutic outcomes of 60-70% drugs. Understanding all key factors in the regulation of expression of the CYP enzymes is critical to predict outcomes of drug therapy. Transcription factors (TFs) of hepatocyte nuclear factor 1a (HNF1a), 4a (HNF4a), pregnane X receptor (PXR), and constitutive androstane receptor (CAR) are the key factors. After binding to their response elements, the TFs facilitate transcriptional regulation through alterations of histone modification status of the CYP genes, the major epigenetic mechanism. A remaining question is how the TFs trigger alterations of histone modifications to facilitate the regulation of CYP expression. lncRNAs may be the key components. Increasing evidence has shown that antisense lncRNAs next to TFs on chromosomal locations are involved in the functions of the TFs in regulation of gene expression. We identified two lncRNAs next to the TFs of HNF1a and HNF4a, which are HNF1a-AS1 and HNF4a-AS1. Several fundamental challenge questions need to be addressed. (1) Whether HNF1a-AS1 and HNF4a-AS1 are the two key factors in maintaining homeostasis of P450 enzymes in liver in a dynamic process, such as drug induction, through enhancing by HNF1a-AS1 or repressing by HNF4a-AS1 in the transcriptional regulation of P450 gene expression? (2) Whether HNF1a-AS1 and HNF4a-AS1 are the two key factors in sensitizing susceptibility of drug induced liver injury (DILI) and following process of liver regeneration? (3) How HNF1a-AS1 and HNF4a-AS1 participate in the regulation of P450 gene expression, directly or indirectly through the regulation of PXR or CAR by alteration of histone modifications? These fundamental questions are so critical for deeply understanding molecular mechanisms in the regulation of CYP-mediated drug metabolism and DILI. In the past five years, we have determined the role of lncRNAs in drug metabolism. Our recent progress has placed us into an appropriate position to provide answers to these fundamental questions. We have developed a comprehensive plan to address these challenge questions with both in vitro and in vivo models in the next five years. After completion of the proposed studies, we expect to provide answers to address the challenge questions. The proposed work will elucidate the epigenetic regulatory mechanisms by lncRNAs that control homeostasis of drug- metabolizing CYP expression in a positive and negative feedback loop after exposure to drugs. The proposed work will determine the roles of lncRNAs in P450-mediated drug metabolism and susceptibility to DILI. The generated knowledge will help to identify novel key factors for predicting therapeutic efficacy and DILI.