自噬调节EMT过程在间质性肺病中的作用机制探讨  

Discussion on the mechanism of autophagy regulating EMT process in interstitial lung disease

作　　者：徐存来 潘炯伟[1] 金元虹[1] 曹卓[1] XU Cunlai;PAN Jiongwei;JIN Yuanhong;CAO Zhuo(Department of Respiratory Medicine and Critical Care Medicine,Lishui People’s Hospital in Zhejiang Province,Lishui323000,China)

机构地区：[1]浙江省丽水市人民医院呼吸与危重症科,浙江丽水323000

出　　处：《中国现代医生》2020年第3期30-34,I0002,共6页China Modern Doctor

基　　金：浙江省丽水市科技局公益性项目(2016GYX29);浙江省医药卫生科技计划项目(2017KY732)。

摘　　要：目的研究不同阶段肺泡Ⅱ型上皮细胞自噬变化,并通过增强自噬水平,观察自噬对间质性肺炎上皮细胞-间充质转化(EMT)的作用与调控机制。方法将小鼠随机分为A空白对照组、B模型组、C自噬增强组各10只。B组及C组气道滴注BLM建立模型,C组腹腔注射mTOR-siRNA。各组分别于干预第7天及第14天随机处死3只小鼠,第28天处死剩下的4只小鼠。记录每只小鼠体重。各组取肺组织进行电镜检查,计数肺泡Ⅱ型上皮细胞自噬体数量,测定不同时期的小鼠肺泡组织中的Smad3、Smad7表达。结果模型7 d组自噬体有所增加,模型14 d、28 d组较空白对照14 d、28 d组无明显变化;自噬增强组各时间组可减轻小鼠肺泡炎及纤维化程度;第14、28 d比较:自噬增强组小鼠Smad3蛋白表达较肺间质纤维化模型组明显降低(P<0.01),较空白对照组小鼠增高(P<0.01);自噬增强组Smad7蛋白表达较肺间质纤维化模型组增加(P<0.05),相比空白对照组低(P<0.01)。自噬增强组的各阶段的肺泡炎和肺纤维化程度与模型组(B组)对比减轻(P<0.05)(除肺纤维化7 d组比较外)。结论肺泡Ⅱ型上皮细胞的自噬变化对EMT具有重要调控作用,mTOR-siRNA可通过调节Smad信号通路参与EMT过程的发生,减少肺间质纤维化形成。Objective To study the changes of autophagy in alveolar type Ⅱ epithelial cells at different stages, and to observe the effect and regulation mechanism of autophagy on epithelial-mesenchymal transition(EMT) of interstitial pneumonia via enhancing autophagy level. Methods Mice were randomly divided into blank control group A, model group B and autophagy enhancement group C, with 10 mice in each group. Models of airway drip BLM were established in group B and group C. Group C was injected intraperitoneally with mTOR-siRNA. Three mice were randomly sacrificed on the 7 th and 14 th day of intervention in each group. On the 28 th day, the remaining 4 mice were sacrificed.The body weight of each mouse was recorded. The lung tissue was collected for electron microscopy in each group. The number of autophagosomes in alveolar type Ⅱ epithelial cells was counted, and the expression of Smad3 and Smad7 in mice alveolar tissues at different stages was determined. Results The autophagosomes in the 7-day model group were increased, and the 14-day and 28-day model groups did not change significantly compared with the 14-day and 28-day blank control groups. The degree of alveolitis and fibrosis in mice could be alleviated in the autophagy enhanced group at each time;the comparison of 14 th and 28 th day: the expression of Smad3 protein in the autophagy enhanced group was significantly lower than that in the pulmonary interstitial fibrosis model group(P<0.01), which was higher than that in the blank control group(P<0.01);the expression of Smad7 in the autophagy enhanced group was higher than that in the model group at each stage(P<0.05), which was lower than that in the blank control group(P<0.01). The degree of alveolitis and pulmonary fibrosis at each stage in the autophagy enhanced group was reduced compared with the model group(group B)(P<0.05)(except the comparison of pulmonary fibrosis at 7 th day). Conclusion Autophagy changes in alveolar type Ⅱ epithelial cells have important regulatory effects on EMT. mTOR-siRNA can

关 键 词：间质性肺疾病 自噬 肺泡Ⅱ型上皮细胞 上皮细胞-间充质转化 

分 类 号：R563[医药卫生—呼吸系统]