miR-210调控Shh信号通路在COPD肺干细胞损伤修复中的作用

Apoptosis of lung epithelial cells is one of the mechanism of ( chronic obstructive pulmonary disease) COPD, in which lung stem cells play an important role. Lung CD45-/CD31-/Sca-1+ cell is a kind of lung stem cell. Sonic hedgehog(Shh) pathway participates in regulating this kind of stem cell. Our preliminary study found that the number of lung CD45-/CD31-/Sca-1+ cells decreased and the expression of Shh pathway reduced in the intraperitoneal injection of cigarette smoke extract( CSE) induced emphysema mice. Over expression of Shh made the number of lung CD45-/CD31-/Sca-1+ cells increase. miR-210 is an important regulating factor for stem cells and can regulate the proliferation and apoptosis of stem cells. In COPD patients and CSE stimulated human bronchial epithelial cells, the expression of miR-210 increased. Shh is its possible target gene. So we build hypothesis that miR-210 can regulate lung CD45-/CD31-/Sca-1+ cells by Shh pathway, which may participate in the pathogenesis of COPD. In this study, we hope verify the hypothesis from studying the human lung tissue, animal modeling and cell culture. We hope we would give an insight into the pathogenesis of COPD.

肺上皮细胞凋亡是慢性阻塞性肺疾病（COPD）的发病机制之一，肺干细胞参与调控肺上皮凋亡。肺CD45-/CD31-/Sca-1+细胞是一种肺干细胞，Shh信号通路参与调控该干细胞的自我更新及分化等功能。前期研究发现在肺气肿小鼠模型中，该干细胞数量下降，Shh信号通路表达下调，过表达Shh蛋白可致该干细胞数量增加。miR-210是与缺氧有关，为干细胞生态位的关键调控介质之一，参与干细胞的调控，可调控细胞凋亡。在COPD患者及CSE刺激后支气管肺上皮细胞中存在miR-210表达上调。Shh通路可能为其靶通路。COPD中是否存在miR-210抑制Shh信号通路影响肺干细胞及肺上皮凋亡尚有待验证。本研究拟从人体肺组织、动物模型、体外细胞上观察miR-210和Shh通路的表达情况及验证miR-210是否调控Shh通路影响肺干细胞细胞，参与调控肺调控肺上皮细胞凋亡及损伤修复失衡，导致COPD的发生。

肺上皮细胞凋亡是慢性阻塞性肺疾病（COPD）的发病机制之一，肺干细胞参与调控肺上皮凋亡。Shh信号通路参与调控干细胞的自我更新及分化等功能。前期研究发现在肺气肿小鼠模型中，肺干细胞数量下降，Shh信号通路表达下调，过表达Shh蛋白可致干细胞数量增加。miR-210是与缺氧有关，为干细胞生态位的关键调控介质之一，参与干细胞的调控，可调控细胞凋亡。COPD中是否存在miR-210及Shh信号通路影响肺干细胞及肺上皮凋亡尚有待验证。本研究从体外细胞实验上观察miR-210和Shh通路的表达情况及验证miR-210是否调控Shh通路影响肺干细胞细胞，参与调控肺调控肺上皮细胞凋亡及损伤修复失衡，导致COPD的发生。通过细胞实验，检测了CSE刺激小鼠II型肺泡上皮细胞MLE-12细胞后，miR-210水平、Shh细胞通路各组分mRNA及蛋白的表达，以及细胞的凋亡情况，实验发现，CSE可下调miR-210水平，抑制Shh细胞通路各组分（Shh、ptch1、Gli1）以及抗凋亡蛋白Bcl-2的mRNA及蛋白的表达，促进细胞的凋亡情况。过表达Shh蛋白可部分逆转CSE所致的细胞凋亡；而进一步抑制miR-210，可下调Shh通路各组分mRNA及蛋白的表达，同时促进凋亡的发生；实验说明，miR-210及Shh均参与CSE所致的细胞凋亡，miR-210可能为Shh通路上游因子。该研究表明，miR-210及Shh通路参与CSE所致II型肺泡上皮细胞凋亡，可能参与COPD的发生，可为将来COPD的可能治疗靶点提供思路。