Thiel-Behnke corneal dystrophy (TBCD) is an epithelial-stromal TGFBI dystrophy caused by mutations in the TGFBI (transforming growth factor beta induced) gene, though the underlying mechanisms and pathogenesis of TBCD are still obscure. The study identifies a novel mutation in the TGFBI gene (p.Gly623_His626del) in a TBCD pedigree. Characteristics of the typical vacuole formation, irregular corneal epithelial thickening and thinning, deposition of eosinophilic substances beneath the epithelium, and involvement of the anterior stroma were observed in this pedigree via transmission electron microscopy (TEM) and histological staining. Tgfbi-p.Gly623_Tyr626del mouse models of TBCD were subsequently generated via CRISPR/Cas9 technology, and the above characteristics were further verified via TEM and histological staining. Lysosomal dysfunction and downregulation of differential expression protein CTSD (cathepsin D) were observed using LysoTracker Green DND-26 and proteomic analysis, respectively. Hence, lysosomal dysfunction probably leads to autophagic flux obstruction in TBCD; this was supported by enhanced LC3-II and SQSTM1 levels and decreased CTSD. TFEB (transcription factor EB) was prominently decreased in TBCD corneal fibroblasts and administration of ATP-competitive MTOR inhibitor torin 1 reversed this decline, resulting in the degradation of accumulated mut-TGFBI (mutant TGFBI protein) via the ameliorative lysosomal function and autophagic flux owing to elevated TFEB activity as measured by western blot, confocal microscopy, and flow cytometry. Transfected HEK 293 cells overexpressing human full-length WT-TGFBI and mut-TGFBI were generated to further verify the results obtained in human corneal fibroblasts. Amelioration of lysosome dysfunction may therefore have therapeutic efficacy in the treatment of TBCD.
基金:
Heilongjiang provincial colleges and universities basic scientific research fund [2018-KYYWF -0484]; Heilongjiang Doctor Fund [2020B03]; Heilongjiang Postdoctoral fund [LBH-Z18185]
第一作者机构:[1]Harbin Med Univ, Affiliated Hosp 1, Dept Ophthalmol, Harbin, Peoples R China
共同第一作者:
通讯作者:
通讯机构:[1]Harbin Med Univ, Affiliated Hosp 1, Dept Ophthalmol, Harbin, Peoples R China[*1]Department of Ophthalmology, The First Affiliated Hospital of Harbin Medical University, Harbin China
推荐引用方式(GB/T 7714):
Wang Liyuan,Zhao Chuchu,Zheng Tao,et al.Torin 1 alleviates impairment of TFEB-mediated lysosomal biogenesis and autophagy in TGFBI (p.G623_H626del)-linked Thiel-Behnke corneal dystrophy[J].AUTOPHAGY.2022,18(4):765-782.doi:10.1080/15548627.2021.1955469.
APA:
Wang, Liyuan,Zhao, Chuchu,Zheng, Tao,Zhang, Yi,Liu, Hanruo...&Liu, Ping.(2022).Torin 1 alleviates impairment of TFEB-mediated lysosomal biogenesis and autophagy in TGFBI (p.G623_H626del)-linked Thiel-Behnke corneal dystrophy.AUTOPHAGY,18,(4)
MLA:
Wang, Liyuan,et al."Torin 1 alleviates impairment of TFEB-mediated lysosomal biogenesis and autophagy in TGFBI (p.G623_H626del)-linked Thiel-Behnke corneal dystrophy".AUTOPHAGY 18..4(2022):765-782