Macular corneal dystrophy (MCD) is ascribed to mutations in the carbohydrate sulfotransferase (CHST6) gene affecting keratan sulfate (KS) hydrophilicity and causing non-sulfated KS to precipitate in keratocytes and the corneal stroma. We investigated roles for inflammatory responses in MCD pathogenesis by examining the lysosomal-autophagy pathway and activation of pyroptosis in MCD keratocytes. Normal and lesioned keratocytes were obtained from MCD patients undergoing corneal transplantation. The keratocytes were subjected to gene sequencing, RT-PCR, western blotting, transmission electron microscopy, histological staining, induction and inhibition assays of autophagy and pyroptosis, CCK-8 and LysoTracker Green DND-26 labeling, and flow cytometry. A novel homozygous MCD mutation was identified in a family from Northeast China; the mutation was distinguished by cytoplasmic vacuolation, cell membrane disruption, electron dense deposits, and deposition of a band of Periodic acid-Schiff and Alcian blue-positive material in the keratocytes and stroma layer. KS protein levels were decreased, expression of p62 and LC3-II proteins was enhanced, cathepsin D expression was declined and the LysoTracker Green DND-26 signal was dramatically reduced in MCD keratocytes. Bafilomycin-A1 treatment significantly increased caspase-1 and Pro-IL-1 beta expression in normal and MCD keratocytes. Nod-like receptors pyrins-3 (NLRP3), caspase-1, Pro-IL-1 beta, and IL-1 beta levels were pronouncedly elevated in cells exposed to H2O2. Ac-YVAD-CMK treatment reversed this expression in normal and MCD keratocytes. Suppression of the autophagic degradation of non-sulfated KS by impaired autophagic flux in MCD keratocytes triggers pyroptosis. Amelioration of impaired autophagy and restraint of pyroptosis may, therefore, have therapeutic efficacy in the treatment of MCD.
基金:
Heilongjiang Postdoctoral fund [LBH-Z18185]; Heilongjiang Doctor Fund [2020B03]; Heilongjiang provincial colleges and universities basic scientific research fund [2018-KYYWF-0484]
第一作者机构:[1]Harbin Med Univ, Affiliated Hosp 1, Dept Ophthalmol, Harbin 150001, Peoples R China
通讯作者:
推荐引用方式(GB/T 7714):
Zheng Tao,Zhao Chuchu,Zhao Baowen,et al.Impairment of the autophagy-lysosomal pathway and activation of pyroptosis in macular corneal dystrophy[J].CELL DEATH DISCOVERY.2020,6(1):doi:10.1038/s41420-020-00320-z.
APA:
Zheng, Tao,Zhao, Chuchu,Zhao, Baowen,Liu, Hanruo,Wang, Shijian...&Liu, Ping.(2020).Impairment of the autophagy-lysosomal pathway and activation of pyroptosis in macular corneal dystrophy.CELL DEATH DISCOVERY,6,(1)
MLA:
Zheng, Tao,et al."Impairment of the autophagy-lysosomal pathway and activation of pyroptosis in macular corneal dystrophy".CELL DEATH DISCOVERY 6..1(2020)