title: Relaxin attenuates silica-induced pulmonary fibrosis by regulating collagen type I and MMP-2.
abstract: Silicosis is one of the most prevalent occupational lung diseases, but the pathogenic mechanisms of silicosis are largely unknown and an effective treatment is not yet available. In this study, we investigated the potential effects of relaxin (RLX) on fibrosis by an in vitro model involving silica-induced and macrophage-mediated pulmonary fibroblasts. Following pre-treatment with DQ12 quartz, the culture supernatant of human monocytic THP-1 cells was added to human fetal lung fibroblast MRC-5 cells with or without RLX. DQ12 significantly induced an increase of TGFB1 mRNA in THP-1 cells, coinciding with elevated TGF-β1 protein excretion in the supernatant, but RLX had no effect on DQ12-stimulated TGF-β1 secretion in THP-1 cells. Furthermore, RLX inhibited the proliferation of MRC-5 cells, and reduced the mRNA level and protein secretion of collagen type I, whereas it increased the mRNA level and protein activity of MMP-2 in MRC-5 cells treated with THP-1 cell culture supernatant. Our data suggest that RLX may inhibit TGF-β1-mediated fibrosis during the process of silicosis, providing evidence for the protective effect of RLX on silica-induced pulmonary fibrosis.
authors: Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 Hubei, PR China; The Ministry of Education Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 Hubei, PR China.
authors: Xiao-Feng
authors: XF
authors: Li
authors: Jing
authors: J
authors: Liao
authors: Zhi-Qiang
authors: ZQ
authors: Xin
authors: Wen-Qing
authors: WQ
authors: Lu
authors: Ai-Lin
authors: AL
authors: Liu
mesh_terms: D002460:Cell Line; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D020011:Protective Agents / Q000494:pharmacology*; D011658:Pulmonary Fibrosis / Q000139:chemically induced / Q000378:metabolism*; D011791:Quartz; D012333:RNA, Messenger / Q000378:metabolism; D012065:Relaxin / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1 / Q000235:genetics
chemical_list: D024042:Collagen Type I; D020011:Protective Agents; D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1; D011791:Quartz; D012065:Relaxin; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2
keywords: Collagen type I; Fibroblast; Macrophage; Matrix metallopeptidase 2; Relaxin; Silicosis