Molecular regulation of cholestasis in cholangiocytes

项目摘要 胆汁淤积是肝脏疾病的常见表现。胆汁淤积通常是由于 特别影响在胆汁分泌中起主要作用的胆管细胞。他们负责 碳酸氢盐分泌到胆汁中并调节胆汁中其它成分的含量。的 III型三磷酸肌醇受体（InsP3R-3）是细胞内主要的钙释放通道 我们以前的研究表明，位于胆管细胞顶部的InsP3R-3对照 碳酸氢盐分泌我们还发现，在大多数胆管形式的人类胆汁淤积症和多个 在动物模型中，InsP3R-3表达缺失，说明钙离子的重要性。 正常胆管细胞功能稳态及其在胆汁淤积中的失调。我们假设 InsP3R-3表达的恢复将改善胆汁淤积并改善胆汁碳酸氢盐 分泌物因此，该资助的长期目标是了解 InsP3R-3在正常和胆汁淤积肝脏中的调节及InsP3R-3恢复的治疗作用 3肝功能的表达。为达致这个目标，我们会推行有关建议， 本研究的主要目的是：（1）研究InsP3R-3基因调控的分子机制 表达将通过研究转录因子（TF）和微RNA（miR）来定义， 分别调控InsP3R-3启动子和mRNA;（2）指导InsP3R-3启动子和mRNA表达的细胞机制 InsP3R-3与胆管细胞亚尖区的结合，包括靶向序列和相互作用 导致这种定位的蛋白质将被建立;（3）导致损失的分子机制 在动物/人胆汁淤积模型（包括InsP3R-3 KO）中InsP3R-3的表达和功能 小鼠和CRISPR/Cas9-InsP3R-3-null人胆管细胞）的细胞因子水平将在 人类胆汁淤积性肝脏此外，我们将研究是否恢复表达特异性 胆汁淤积中的TF/miR-抗miR导致疾病的改善。总而言之，数据来自 这些研究将提高我们对胆管细胞分泌调节的理解， 有可能导致设计新的治疗方法来治疗胆汁淤积性 紊乱

PROJECT SUMMARY Cholestasis is a common manifestation of liver disease. Cholestasis often is due to disorders specifically affecting cholangiocytes, which play a major role in bile secretion. They are responsible for secretion of bicarbonate into bile and modulating the biliary contents of other constituents as well. The type III inositol trisphosphate receptor (InsP3R-3) is the primary intracellular calcium release channel in cholangiocytes and our previous studies have shown that apically-localized InsP3R-3 controls bicarbonate secretion. We also found that in most ductular forms of human cholestasis and in multiple animal models, there is loss of InsP3R-3 expression, underlying the importance of calcium homeostasis in normal cholangiocyte function and its dysregulation in cholestasis. We hypothesize that restoration of InsP3R-3 expression will ameliorate cholestasis and improve biliary bicarbonate secretion. Thus the long term objective of this grant is to understand the molecular mechanisms of InsP3R-3 regulation in normal and cholestatic liver and the therapeutic effect of restoration of InsP3R- 3 expression on liver function. To achieve this objective, the proposal will be implemented with the following specific aims: (1) The molecular factors governing the regulation of InsP3R-3 gene expression will be defined by studying the transcription factors (TFs) and microRNAs (miRs) that regulate the InsP3R-3 promoter and mRNA respectively; (2) The cellular mechanisms that direct InsP3R-3 to the subapical region of cholangiocytes including targeting sequences and interacting proteins that lead to such localization will be established; (3) Molecular mechanisms that lead to loss of InsP3R-3 expression and function in animal/human models of cholestasis (including InsP3R-3 KO mice and CRISPR/Cas9-InsP3R-3-null human cholangiocytes) will be determined and verified in human cholestatic liver. Further, we will investigate whether restoration of expression-specific TFs/miRs-anti-miRs in cholestasis results in improvement of disease. Together, the data derived from these studies will improve our understanding of the regulation of secretion in cholangiocytes, and have the potential to lead to design of novel therapeutic approaches for the treatment of cholestatic disorders.