Autophagy in Idiopathic Pulmonary Fibrosis

View/ Open
Author
Lin, Ling
Geyer, Alexander
An, Chang Hyeok
Cao, Jiaofei
Morse, Danielle
Published Version
https://doi.org/10.1371/journal.pone.0041394Metadata
Show full item recordCitation
Patel, Avignat S., Ling Lin, Alexander Geyer, Jeffrey A. Haspel, Chang Hyeok An, Jiaofei Cao, Ivan O. Rosas, and Danielle Morse. 2012. Autophagy in idiopathic pulmonary fibrosis. PLoS ONE 7(7): e41394.Abstract
Background: Autophagy is a basic cellular homeostatic process important to cell fate decisions under conditions of stress. Dysregulation of autophagy impacts numerous human diseases including cancer and chronic obstructive lung disease. This study investigates the role of autophagy in idiopathic pulmonary fibrosis. Methods: Human lung tissues from patients with IPF were analyzed for autophagy markers and modulating proteins using western blotting, confocal microscopy and transmission electron microscopy. To study the effects of TGF-β1 on autophagy, human lung fibroblasts were monitored by fluorescence microscopy and western blotting. In vivo experiments were done using the bleomycin-induced fibrosis mouse model. Results: Lung tissues from IPF patients demonstrate evidence of decreased autophagic activity as assessed by LC3, p62 protein expression and immunofluorescence, and numbers of autophagosomes. TGF-β1 inhibits autophagy in fibroblasts in vitro at least in part via activation of mTORC1; expression of TIGAR is also increased in response to TGF-β1. In the bleomycin model of pulmonary fibrosis, rapamycin treatment is antifibrotic, and rapamycin also decreases expression of á-smooth muscle actin and fibronectin by fibroblasts in vitro. Inhibition of key regulators of autophagy, LC3 and beclin-1, leads to the opposite effect on fibroblast expression of á-smooth muscle actin and fibronectin. Conclusion: Autophagy is not induced in pulmonary fibrosis despite activation of pathways known to promote autophagy. Impairment of autophagy by TGF-β1 may represent a mechanism for the promotion of fibrogenesis in IPF.Other Sources
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3399849/pdf/Terms of Use
This article is made available under the terms and conditions applicable to Other Posted Material, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAACitable link to this page
http://nrs.harvard.edu/urn-3:HUL.InstRepos:10445569
Collections
- HMS Scholarly Articles [15665]
Contact administrator regarding this item (to report mistakes or request changes)