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Zhou L, Liu Z, Chen S, Qiu J, Li Q, Wang S, Zhou W, Chen D, Yang G, Guo L. Transcription factor EB‑mediated autophagy promotes dermal fibroblast differentiation and collagen production by regulating endoplasmic reticulum stress and autophagy‑dependent secretion. Int J Mol Med 2020; 47:547-560. [PMID: 33416091 PMCID: PMC7797452 DOI: 10.3892/ijmm.2020.4814] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 11/11/2020] [Indexed: 01/18/2023] Open
Abstract
Autophagy is reported to be involved in the formation of skin hypertrophic scar (HTS). However, the role of autophagy in the process of fibrosis remains unclear, therefore an improved understanding of the molecular mechanisms associated with autophagy may accelerate the development of effective therapeutic strategies against HTS. The present study evaluated the roles of autophagy mediated by transcription factor EB (TFEB), a pivotal regulator of lysosome biogenesis and autophagy, in transforming growth factor-β1 (TGF-β1)-induced fibroblast differentiation and collagen production. Fibroblasts were treated with TGF-β1, TGF-β1 + tauroursodeoxycholic acid (TUDCA) or TGF-β1 + TFEB-small interfering RNA (siRNA). TGF-β1 induced phenotypic transformation of fibro-blasts, as well as collagen synthesis and secretion in fibroblasts in a dose-dependent manner. Western blotting and immuno-fluorescence analyses demonstrated that TGF-β1 upregulated the expression of autophagy-related proteins through the endoplasmic reticulum (ER) stress pathway, whereas TUDCA reversed TGF-β1-induced changes. Reverse transcription-quantitative PCR (RT-qPCR), western blotting and RFP-GFP-LC3 double fluorescence analyses demonstrated that knockdown of TFEB by TFEB-siRNA decreased autophagic flux, upregulated the expression of proteins involved in the apoptotic pathway, such as phosphorylated-α subunit of eukaryotic initiation factor 2, C/EBP homologous protein and cysteinyl aspartate specific proteinase 3, and also downregulated the expression of α-smooth muscle actin and collagen I (COL I) in fibroblasts. Immunofluorescence confocal analyses and enzyme-linked immunosorbent assay indicated that TGF-β1 increased the colocalization of COL I with lysosomal-associated membrane protein 1 and Ras-related protein Rab-8A, a marker of secretory vesicles, in fibroblasts, as well as the secretion of pro-COL Iα1 in culture supernatants. Meanwhile, these effects were abolished by TFEB knockdown. The present results suggested that autophagy reduced ER stress, decreased cell apoptosis and maintained fibroblast activation not only through degradation of misfolded or unfolded proteins, but also through promotion of COL I release from the autolysosome to the extracellular environment.
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Affiliation(s)
- Ling Zhou
- Department of Plastic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Zeming Liu
- Department of Plastic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Sichao Chen
- Department of Plastic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Jing Qiu
- Department of Geriatrics, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, Hubei 430070, P.R. China
| | - Qianqian Li
- Department of Plastic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Shipei Wang
- Department of Plastic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Wei Zhou
- Department of Plastic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Danyang Chen
- Department of Plastic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Guang Yang
- Department of Geriatrics, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, Hubei 430070, P.R. China
| | - Liang Guo
- Department of Plastic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
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Targeted apoptosis of myofibroblasts by elesclomol inhibits hypertrophic scar formation. EBioMedicine 2020; 54:102715. [PMID: 32251998 PMCID: PMC7132150 DOI: 10.1016/j.ebiom.2020.102715] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 11/21/2022] Open
Abstract
Background Hypertrophic scar (HS) is characterized by the increased proliferation and decreased apoptosis of myofibroblasts. Myofibroblasts, the main effector cells for dermal fibrosis, develop from normal fibroblasts. Thus, the stimulation of myofibroblast apoptosis is a possible treatment for HS. We aimed to explore that whether over-activated myofibroblasts can be targeted for apoptosis by anticancer drug elesclomol. Methods 4′,6-diamidino-2-phenylindole staining, flow cytometry, western blotting, collagen gel contraction and immunofluorescence assays were applied to demonstrate the proapoptotic effect of elesclomol in scar derived myofibroblasts and TGF-β1 induced myofibroblasts. The therapeutic potential of elesclomol was investigated by establishing rabbit ear hypertrophic scar models. Findings Both 4′,6-diamidino-2-phenylindole staining and flow cytometry indicated that elesclomol targets myofibroblasts in vitro. Collagen gel contraction assay showed that elesclomol inhibited myofibroblast contractility. Flow cytometry and western blot analysis revealed that elesclomol resulted in excessive intracellular levels of reactive oxygen species(ROS), and caspase-3 and cytochrome c proteins. Moreover, compared with the control group, the elesclomol group had a significantly lower scar elevation index in vivo. Immunofluorescence assays for TUNEL and α-smooth muscle actin indicated that elesclomol treatment increased the number of apoptotic myofibroblasts. Interpretation The above results indicate that elesclomol exerted a significant inhibitory effect on HS formation via targeted myofibroblast apoptosis associated with increased oxidative stress. Thus, elesclomol is a promising candidate drug for the treatment of myofibroblast-related diseases such as HS.
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Feng Y, Sun ZL, Yuan FL. Comments on "A new approach in the treatment of pediatric hypertrophic burn scars: Tixel-associated topical triamcinolone acetonide and 5-fluorouracil delivery". J Cosmet Dermatol 2019; 19:1804. [PMID: 31793718 DOI: 10.1111/jocd.13231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 11/12/2019] [Indexed: 11/29/2022]
Affiliation(s)
- Yi Feng
- Department of Burns and Plastic Surgery, The Affiliated Hospital of Jiangnan University, Wuxi, China.,Department of Pharmacology, Medical School, Yangzhou University, Yangzhou, China
| | - Zi-Li Sun
- Department of Burns and Plastic Surgery, The Affiliated Hospital of Jiangnan University, Wuxi, China.,Wuxi Clinical Medicine School of Integrated Chinese and Western Medicine, Nanjing University of Chinese Medicine, Wuxi, China
| | - Feng-Lai Yuan
- Department of Burns and Plastic Surgery, The Affiliated Hospital of Jiangnan University, Wuxi, China
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