GJ的Ca2+传递引起钙稳态失衡诱导内质网应激在肝移植术后急性肾损伤中的作用研究

项目名称： GJ的Ca2+传递引起钙稳态失衡诱导内质网应激在肝移植术后急性肾损伤中的作用研究

项目编号： No.81500493

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 医药、卫生

项目作者： 王艳玲

作者单位： 中山大学

项目金额： 18万元

中文摘要： 肝移植急性肾损伤（AKI）是导致患者恢复延迟和死亡的主要原因，机制复杂且缺乏有效防治手段。内质网应激（ERS）是引起细胞损伤的重要原因，钙稳态失衡是ERS的中心环节，但抑制钙泵却未能完全恢复钙稳态，提示我们可能有其它通道参与。我们前期研究证明，缝隙连接(GJ)传递信号参与内毒素和胆红素诱导的肾小管上皮细胞损伤，GJ可以传递Ca2+，且抑制GJ可降低细胞内Ca2+水平，减少ERS相关凋亡蛋白CHOP和Caspase12的表达。据此，我们假设“GJ作为钙传递的另一通道引起钙稳态失衡，进而诱导的ERS是引起肝移植AKI的重要原因”。我们拟用胆红素和内毒素细胞损伤模型、野生型和Cx32-/-小鼠肝移植模型、结合基因沉默和质粒转染及改变GJ功能等技术，检测肾损伤、GJ的钙传递、ERS相关凋亡等指标来证明假说，阐明肝移植早期AKI的机制，为防治肝移植AKI提供有效干预靶点和理论依据。

中文关键词： 肝移植；急性肾损伤；缝隙连接；内质网应激；钙稳态失衡

英文摘要： The early occurrence of acute kidney injury (AKI) after liver transplantation (LT) is the main reason for patients recovery delay and high post-operation morbidity, but the exact mechanism and preventive strategy is still obscure. Endoplasmic reticulum stress (ERS), contributing to kind of cell apoptosis process, was considered as the main cause of cell damage and cell death. Meanwhile, calcium dyshomeostasis was the central part of ERS. Of note, our preliminary study found that gap junction (GJ), the direct intercellular pathway for exchange of information, involved in the process of renal tubular epithelium (NRK52E cells) injury induced by bilirubin or lipopolysaccharide. Moreover, the damage process was accompanied by the alteration of intracellular Ca2+ concentration ([Ca2+]i). GJ inhibitor could effectively decrease [Ca2+]i and expressions of CHOP and Caspase 12 protein, two ERS associated apoptosis protein. Based on the above, we hypothesize that the early AKI after LT is accommodated by ERS induced by GJ regulated calcium dyshomeostasis. Various methods, such as sepicific inhibitor, gene silencing and Cx32 gene knockout mice, will be applied to change GJ function, in order to clarify its effects and role in the development of AKI following LT and most importantly to verify whether GJ mediates AKI through modulating ERS associated cell apoptosis induced by GJ regulated calcium dyshomeostasis. This topic will provide valid basis and strong theoretical evidence for determination of mechanism and prevention measure for the occurrence of early AKI after LT.

英文关键词： liver transplantation;acute kidney injury;gap junction;endoplasmic reticulum stress;calcium dyshomeostasis