Mao Cuiping, Zhang Jinjin, Lin Shengcui, Jing Lili, Xiang Jing, Wang Meirong, Wang Bingsi, Xu Pan, Liu Weili, Song Xiaodong, Lv Changjun
Molecular Medicine Research Center, Binzhou Medical University, Yantai, China.
J Cell Mol Med. 2014 Dec;18(12):2404-16. doi: 10.1111/jcmm.12420. Epub 2014 Oct 6.
Apoptosis of type II alveolar epithelial cells (AECs-II) is a key determinant of initiation and progression of lung fibrosis. However, the mechanism of miR-30a participation in the regulation of AECs-II apoptosis is ambiguous. In this study, we investigated whether miR-30a could block AECs-II apoptosis by repressing mitochondrial fission dependent on dynamin-related protein-1 (Drp-1). The levels of miR-30a in vivo and in vitro were determined through quantitative real-time PCR (qRT-PCR). The inhibition of miR-30a in AECs-II apoptosis, mitochondrial fission and its dependence on Drp-1, and Drp-1 expression and translocation were detected using miR-30a mimic, inhibitor-transfection method (gain- and loss-of-function), or Drp-1 siRNA technology. Results showed that miR-30a decreased in lung fibrosis. Gain- and loss-of-function studies revealed that the up-regulation of miR-30a could decrease AECs-II apoptosis, inhibit mitochondrial fission, and reduce Drp-1 expression and translocation. MiR-30a mimic/inhibitor and Drp-1 siRNA co-transfection showed that miR-30a could inhibit the mitochondrial fission dependent on Drp-1. This study demonstrated that miR-30a inhibited AECs-II apoptosis by repressing the mitochondrial fission dependent on Drp-1, and could function as a novel therapeutic target for lung fibrosis.
II型肺泡上皮细胞（AECs-II）凋亡是肺纤维化发生和发展的关键决定因素。然而，miR-30a参与调控AECs-II凋亡的机制尚不清楚。在本研究中，我们探究了miR-30a是否可通过抑制依赖动力相关蛋白1（Drp-1）的线粒体分裂来阻止AECs-II凋亡。通过定量实时PCR（qRT-PCR）测定体内和体外miR-30a的水平。使用miR-30a模拟物、抑制剂转染方法（功能获得和功能缺失）或Drp-1 siRNA技术检测miR-30a对AECs-II凋亡、线粒体分裂及其对Drp-1的依赖性，以及Drp-1表达和转位的影响。结果显示，肺纤维化时miR-30a水平降低。功能获得和功能缺失研究表明，miR-30a上调可减少AECs-II凋亡，抑制线粒体分裂，并降低Drp-1表达和转位。miR-30a模拟物/抑制剂与Drp-1 siRNA共转染显示，miR-30a可抑制依赖Drp-1的线粒体分裂。本研究表明，miR-30a通过抑制依赖Drp-1的线粒体分裂来抑制AECs-II凋亡，可作为肺纤维化的新型治疗靶点。
