Vimentin-Rab7a通路介导骨髓间充质干细胞迁移治疗急性呼吸窘迫综合征的机制研究

Acute respiratory distress syndrome (ARDS) is a severe disease, which has rapid onset and gradual progress. The lack of effective etiopathology treatment of the disease bring about high mortality at present. Mesenchymal stem cells (MSCs) have therapeutic effects on ARDS, but the molecular mechanism of the migration, the role of cytoskeleton and signal transduction proteins are unclear. Our studies showed that the knockout of Vimentin gene in MSCs significantly decreased the migration and influenced the treatment of ARDS. Meanwhile, we had interestingly found that it had interaction between Vimentin and GTP binding protein 7a (Rab7a). So, we hypothesized that Vimentin/Rab7a may play important roles in MSCs migration and the treatment of ARDS. Thereby, this project was designed to further explore the effect of vimentin/Rab7a modulation with MSCs by ARDS model in vivo and MSCs model in vitro, including: 1. The effect and mechanism of Vimentin or Rab7a, using siRNA interference/lentivirus transfection, on MSCs cell migration, cell morphology, pathological changes of lung tissue, the expression of inflammatory factors and survival rate of mice; 2. Potential dynamics proteins were screened to explore the relationship between Rab7a by Immunoprecipitation technology; 3. Yeast two hybrid, total internal reflection fluorescence and western blot technology were used to investigate the co-localization of Vimentin/Rab7a and the interaction mechanism. The completion of this study is likely to find a new mechanism of MSCs migration in the treatment of ARDS, and provide new targets for clinical intervention.

呼吸窘迫综合征（ARDS）病情发展快、治疗困难、死亡率较高。间充质干细胞（MSCs）对ARDS具有重要的治疗作用，但其主要存在于脊髓中，MSCs如何迁移至肺部其机制尚且不清，明确其中作用对临床意义重大。课题组前期研究发现：静脉注射野生型小鼠MSCs可以治疗ARDS，而波形蛋白（Vimentin）基因敲除后MSCs的迁移力降低、治疗作用也明显减弱；进一步研究发现，信号传递分子Rab7a可以和Vimentin结合并相互作用调节细胞骨架的结构。据此本课题拟通过ARDS动物、MSCs细胞模型研究：siRNA干扰/慢病毒转染Vimentin、Rab7a基因对MSCs细胞迁移及肺部炎症的影响；酵母双杂交、Western blot、全内反射荧光技术探索Vimentin-Rab7a蛋白相互作用机制及其对细胞骨架的影响。本课题的顺利完成有可能发现MSCs迁移治疗ARDS的新机制，为临床干预提供新的靶点。

呼吸窘迫综合征（ARDS）病情发展快、治疗困难、死亡率较高。间充质干细胞（MSCs）对ARDS具有重要的治疗作用，明确MSCs如何迁移至肺部及其中的机制意义重大。本课题主要研究了Vimentin-Rab7a如何调控MSCs迁移及两者之间的关系，具体包括三个方面：①明确Vimentin在MSCs迁移治疗ARDS中的作用及机制；②明确Rab7a在MSCs迁移治疗ARDS中的作用及机制；③明确Vimentin与Rab7a之间的相互作用及机制。结果发现，ARDS小鼠炎症信号通路被激活后，MSCs中Vimentin蛋白被活化，Vimentin通过重塑细胞骨架促进MSCs迁移到受损肺泡修复肺泡上皮细胞，从而实现对ARDS的治疗作用；Rab7a作为小分子信号蛋白可以与Vimentin蛋白结合，促进其磷酸化并提供迁移的动力，共同促进MSCs迁移，治疗ARDS所致肺损伤。本课题的顺利完成为将为临床ARDS的治疗提供新的靶点和思路，为MSCs应用的临床转化提供理论依据。