Crif1竞争抑制PKI结合PKAαcat促进BM-MSCs放射后成脂分化的作用机制研究

项目名称： Crif1竞争抑制PKI结合PKAαcat促进BM-MSCs放射后成脂分化的作用机制研究

项目编号： No.81502754

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： 相丽欣

作者单位： 中国人民解放军第三军医大学

项目金额： 18万元

中文摘要： 造血微环境结构和功能异常致造血抑制是骨髓型急性放射病的主要病理机制。而BM-MSCs成骨、成脂定向分化失衡是其造血支持功能缺失的关键环节。研究表明放射可致其成骨（减弱）、成脂（增强）定向分化失衡。前期研究发现，放射诱导BM-MSCs高表达Crif1并激活PKAα cat促进其成脂分化，其分子机制未明。生物信息学分析发现，Crif1、PKI与PKAα cat存在关键结合位点重叠。由此推测Crif1竞争抑制PKI结合PKAα cat促进BM-MSCs成脂分化。本项目拟构建Crif1及PKAα cat截短体确定二者相互作用关键位点，研究Crif1调控PKAα cat的机制；在此基础上，诱导核心结合序列突变，研究Crif1/PKI-PKAα cat调控BM-MSCs放射后成脂分化的相互作用关系，阐明Crif1致放射后BM-MSCs定向分化失衡的分子机制，为骨髓型急性放射病造血重建救治提供新思路。

中文关键词： 放射损伤；Crif1；骨髓间充质干细胞；成脂分化；PKA

英文摘要： The damaged structure and dysfunction of hematopoietic microenvironment causing myelosuppression is the main pathological mechanism of radiation bone marrow syndrome. However, the imbalance between osteogenic and adipogenic differentiation of BM-MSCs is the key event of the loss of hematopoietic support function. Researches have shown that irradiation caused the imbalance between osteogenic (weakened) and adipogenic (enhanced) differentiation of BM-MSCs. Our previous research showed that irradiation induced the high expression of Crif1 and the activation of PKAα cat promoting the adipogenic differentiation, but the molecular mechanism is unknown. Bioinformatic analysis reveal that Crif1 and PKI have key binding sites overlap on PKAα cat. Hence, we infer that Crif1 competitively inhibits the combination between PKI and PKAα cat promoting the adipogenic differentiation of BM-MSCs. To uncover the mechanism that how Crif1 regulates PKAα cat, we propose to construct the truncated mutants of Crif1 and PKAα cat to identify the key binding sites; on this basis, induce the mutations of core sequences to research the mutual relations of Crif1/PKI- PKAα cat in regulating the adipogenic differentiation of BM-MSCs after irradiation. We hope to clarify the mechanism of the imbalanced differentiation of BM-MSCs caused by Crif1 after irradiation and to provide a new way of thinking to hematopoietic reconstruction in the treatment of radiation bone marrow syndrome.

英文关键词： irradiation injury;Crif1;BM-MSCs;adipogenic differentiation;PKA