title: Adiponectin attenuates lung fibroblasts activation and pulmonary fibrosis induced by paraquat.
abstract: Pulmonary fibrosis is one of the most common complications of paraquat (PQ) poisoning, which demands for more effective therapies. Accumulating evidence suggests adiponectin (APN) may be a promising therapy against fibrotic diseases. In the current study, we determine whether the exogenous globular APN isoform protects against pulmonary fibrosis in PQ-treated mice and human lung fibroblasts, and dissect the responsible underlying mechanisms. BALB/C mice were divided into control group, PQ group, PQ + low-dose APN group, and PQ + high-dose APN group. Mice were sacrificed 3, 7, 14, and 21 days after PQ treatment. We compared pulmonary histopathological changes among different groups on the basis of fibrosis scores, TGF-β1, CTGF and α-SMA pulmonary content via Western blot and real-time quantitative fluorescence-PCR (RT-PCR). Blood levels of MMP-9 and TIMP-1 were determined by ELISA. Human lung fibroblasts WI-38 were divided into control group, PQ group, APN group, and APN receptor (AdipoR) 1 small-interfering RNA (siRNA) group. Fibroblasts were collected 24, 48, and 72 hours after PQ exposure for assay. Cell viability and apoptosis were determined via Kit-8 (CCK-8) and fluorescein Annexin V-FITC/PI double labeling. The protein and mRNA expression level of collagen type III, AdipoR1, and AdipoR2 were measured by Western blot and RT-PCR. APN treatment significantly decreased the lung fibrosis scores, protein and mRNA expression of pulmonary TGF-β1, CTGF and α-SMA content, and blood MMP-9 and TIMP-1 in a dose-dependent manner (p<0.05). Pretreatment with APN significantly attenuated the reduced cell viability and up-regulated collagen type III expression induced by PQ in lung fibroblasts, (p<0.05). APN pretreatment up-regulated AdipoR1, but not AdipoR2, expression in WI-38 fibroblasts. AdipoR1 siRNA abrogated APN-mediated protective effects in PQ-exposed fibroblasts. Taken together, our data suggests APN protects against PQ-induced pulmonary fibrosis in a dose-dependent manner, via suppression of lung fibroblast activation. Functional AdipoR1 are expressed by human WI-38 lung fibroblasts, suggesting potential future clinical applicability of APN against pulmonary fibrosis.
authors.affiliation: Emergency Medicine Department, West China Hospital, Sichuan University, 37 Guoxue Road, Chengdu, Sichuan, 610041, PR China.
authors.forename: Rong
authors.initials: R
authors.lastname: Yao
authors.affiliation: Emergency Medicine Department, West China Hospital, Sichuan University, 37 Guoxue Road, Chengdu, Sichuan, 610041, PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Emergency Medicine Department, West China Hospital, Sichuan University, 37 Guoxue Road, Chengdu, Sichuan, 610041, PR China.
authors.forename: Ya-rong
authors.initials: YR
authors.lastname: He
authors.affiliation: Emergency Medicine Department of Thomas Jefferson University Hospital, 1025 Walnut Street, 808 College Building, Philadelphia, PA, 19107, United States of America.
authors.forename: Wayne Bond
authors.initials: WB
authors.lastname: Lau
authors.affiliation: Emergency Medicine Department, West China Hospital, Sichuan University, 37 Guoxue Road, Chengdu, Sichuan, 610041, PR China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zeng
authors.affiliation: Respiratory Department, West China Hospital, Sichuan University, 37 Guoxue Road, Chengdu, Sichuan, 610041, PR China.
authors.forename: Zong-an
authors.initials: ZA
authors.lastname: Liang
mesh_terms: D000199:Actins / Q000378:metabolism; D052242:Adiponectin / Q000627:therapeutic use*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival; D024061:Collagen Type III / Q000096:biosynthesis / Q000235:genetics; D055513:Connective Tissue Growth Factor / Q000378:metabolism; D005347:Fibroblasts / Q000473:pathology; D006801:Humans; D008168:Lung / Q000473:pathology; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000097:blood; D051379:Mice; D008807:Mice, Inbred BALB C; D010269:Paraquat / Q000506:poisoning*; D011658:Pulmonary Fibrosis / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D034741:RNA, Small Interfering; D011897:Random Allocation; D054419:Receptors, Adiponectin / Q000096:biosynthesis* / Q000235:genetics; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000097:blood; D053773:Transforming Growth Factor beta1 / Q000378:metabolism
chemical_list: C475418:ADIPOR1 protein, human; C475420:ADIPOR2 protein, human; D000199:Actins; D052242:Adiponectin; C526318:CCN2 protein, mouse; D024061:Collagen Type III; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D054419:Receptors, Adiponectin; C508961:Tgfb1 protein, mouse; C560825:Timp1 protein, mouse; D019715:Tissue Inhibitor of Metalloproteinase-1; D053773:Transforming Growth Factor beta1; C544013:alpha-smooth muscle actin, mouse; D055513:Connective Tissue Growth Factor; D020780:Matrix Metalloproteinase 9; C501830:Mmp9 protein, mouse; D010269:Paraquat