Tian Rui, Zhu Yong, Yao Jiayi, Meng Xiaoxiao, Wang Jinfeng, Xie Hui, Wang Ruilan
Department of Critical Care Medicine, Shanghai General Hospital of Nanjing Medical University, Shanghai, China.
Department of Critical Care Medicine, Shanghai General Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, China.
Exp Cell Res. 2017 Aug 15;357(2):328-334. doi: 10.1016/j.yexcr.2017.05.028. Epub 2017 Jun 4.
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and irreversible lung disease. Studies have shown that epithelial-mesenchymal transition (EMT) plays an important role in the development of IPF. The NLRP3 inflammasome is reported to be activated and play an important role in many respiratory diseases. However, whether the NLRP3 inflammasome is activated in alveolar epithelial cells as well as the regulatory role of NLRP3 in EMT have not been reported. In this study, we transfected NLRP3 siRNA into A549 and RLE-6TN cells and treated them with bleomycin (BLM) for 24h. Then, we detected the expression of NLRP3 inflammasome-related proteins, EMT-related proteins and transforming growth factor-β1 (TGF-β1) via western blotting, immunofluorescence and real-time quantitative PCR. The mRNA and protein level of NLRP3, ASC and caspase-1 increased after treatment with BLM. The IL-1β levels were significantly decreased after inhibition of NLRP3 and caspase-1. E-cadherin expression increased and α-SMA was reduced in the BLM group when inhibited by NLRP3. The level of TGF-β1 was reduced after NLRP3 silencing. These results indicated that the NLRP3 inflammasome was activated in alveolar epithelial cells and that NLRP3 may regulate EMT through TGF-β1. These results may extend our understanding of the mechanism of pulmonary fibrosis and provide a new therapeutic target for pulmonary fibrosis.
特发性肺纤维化（IPF）是一种慢性、进行性且不可逆的肺部疾病。研究表明，上皮-间质转化（EMT）在IPF的发展中起重要作用。据报道，NLRP3炎性小体被激活并在许多呼吸系统疾病中起重要作用。然而，NLRP3炎性小体在肺泡上皮细胞中是否被激活以及NLRP3在EMT中的调节作用尚未见报道。在本研究中，我们将NLRP3 siRNA转染到A549和RLE-6TN细胞中，并用博来霉素（BLM）处理24小时。然后，我们通过蛋白质免疫印迹法、免疫荧光法和实时定量PCR检测NLRP3炎性小体相关蛋白、EMT相关蛋白和转化生长因子-β1（TGF-β1）的表达。用BLM处理后，NLRP3、ASC和caspase-1的mRNA和蛋白水平升高。抑制NLRP3和caspase-1后，IL-1β水平显著降低。当被NLRP3抑制时，BLM组中E-钙黏蛋白表达增加而α-平滑肌肌动蛋白减少。NLRP3沉默后，TGF-β1水平降低。这些结果表明NLRP3炎性小体在肺泡上皮细胞中被激活，并且NLRP3可能通过TGF-β1调节EMT。这些结果可能会扩展我们对肺纤维化机制的理解，并为肺纤维化提供新的治疗靶点。
