Xiao-Zhou Zou1, Zhi-Cheng Gong2, Ting Liu1, Fang He1, Tian-Tian Zhu1, Dai Li3, Wei-Fang Zhang4, Jun-Lin Jiang5, Chang-Ping Hu6. 1. Department of Pharmacology, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, Hunan 410078, China. 2. Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China. 3. Department of Pharmacy, The Second People's Hospital of Hefei, Hefei, Anhui 230011, China. 4. Department of Pharmacy, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 33006, China. 5. Department of Pharmacology, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, Hunan 410078, China; Hunan Provincial Key Laboratory of Cardiovascular Research, Central South University, Changsha, Hunan 410078, China. Electronic address: junlinjiang@csu.edu.cn. 6. Department of Pharmacology, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, Hunan 410078, China; Hunan Provincial Key Laboratory of Cardiovascular Research, Central South University, Changsha, Hunan 410078, China. Electronic address: huchangping@yahoo.com.
Abstract
BACKGROUND AND OBJECTIVE: Diabetic pulmonary fibrosis is a severe disease that increases mortality risk of diabetes. However, the molecular mechanisms leading to pulmonary fibrosis in diabetes are poorly understood. This study investigated the roles of epithelial-mesenchymal transition (EMT) and the associated molecular mechanisms in streptozotocin (STZ)-induced rat pulmonary fibrosis. METHODS: The rat model of diabetic pulmonary fibrosis was established by intraperitoneal injection of a single dose of STZ (35 mg/kg). Typical lesions of diabetic pulmonary fibrosis were observed 8 weeks after STZ injection by hematoxylin-eosin (HE) and Masson staining. Human bronchial epithelial cells (HBECs) and A549 cells were treated by high glucose. Gene or protein expression was measured by real-time PCR, Western blot, immunohistochemistry or immunofluorescence. The knockdown of lectin-like oxidized low density lipoprotein receptor-1 (LOX-1) or transforming growth factor-β1 (TGF-β1) was conducted by siRNA. RESULTS: Activation of EMT was observed in lung tissues of STZ-induced diabetic rats, exhibiting a loss in the epithelial cell marker E-cadherin and an increase in the mesenchymal marker Vimentin. The protein and mRNA levels of LOX-1, TGF-β1 and krüppel-like factor 6 (KLF6) in the lung tissues were increased. Incubation of HBECs and A549 cells with high glucose activated EMT and induced an increase in LOX-1, TGF-β1 and KLF-6 expression. LOX-1 siRNA inhibited high glucose-induced EMT in HBECs and A549 cells, which correlated with the reduction of TGF-β1. TGF-β1 siRNA decreased the expression of LOX-1 and KLF6. CONCLUSIONS: EMT was involved in the pathological process of diabetic pulmonary fibrosis, which was activated by LOX-1/TGF-β1/KLF6 signaling pathway.
BACKGROUND AND OBJECTIVE:Diabetic pulmonary fibrosis is a severe disease that increases mortality risk of diabetes. However, the molecular mechanisms leading to pulmonary fibrosis in diabetes are poorly understood. This study investigated the roles of epithelial-mesenchymal transition (EMT) and the associated molecular mechanisms in streptozotocin (STZ)-induced ratpulmonary fibrosis. METHODS: The rat model of diabetic pulmonary fibrosis was established by intraperitoneal injection of a single dose of STZ (35 mg/kg). Typical lesions of diabetic pulmonary fibrosis were observed 8 weeks after STZ injection by hematoxylin-eosin (HE) and Masson staining. Human bronchial epithelial cells (HBECs) and A549 cells were treated by high glucose. Gene or protein expression was measured by real-time PCR, Western blot, immunohistochemistry or immunofluorescence. The knockdown of lectin-like oxidized low density lipoprotein receptor-1 (LOX-1) or transforming growth factor-β1 (TGF-β1) was conducted by siRNA. RESULTS: Activation of EMT was observed in lung tissues of STZ-induced diabeticrats, exhibiting a loss in the epithelial cell marker E-cadherin and an increase in the mesenchymal marker Vimentin. The protein and mRNA levels of LOX-1, TGF-β1 and krüppel-like factor 6 (KLF6) in the lung tissues were increased. Incubation of HBECs and A549 cells with high glucose activated EMT and induced an increase in LOX-1, TGF-β1 and KLF-6 expression. LOX-1 siRNA inhibited high glucose-induced EMT in HBECs and A549 cells, which correlated with the reduction of TGF-β1. TGF-β1 siRNA decreased the expression of LOX-1 and KLF6. CONCLUSIONS: EMT was involved in the pathological process of diabetic pulmonary fibrosis, which was activated by LOX-1/TGF-β1/KLF6 signaling pathway.
Authors: Sun Young Cho; Jeong-Hyun Choi; Seung Hyeun Lee; Yong-Sung Choi; Sung Wook Hwang; Young Jin Kim Journal: PLoS One Date: 2021-11-05 Impact factor: 3.240