title: Disrupted cell cycle arrest and reduced proliferation in corneal fibroblasts from GCD2 patients: a potential role for altered autophagy flux.
abstract: This study investigates the role of impaired proliferation, altered cell cycle arrest, and defective autophagy flux of corneal fibroblasts in granular corneal dystrophy type 2 (GCD2) pathogenesis. The proliferation rates of homozygous (HO) GCD2 corneal fibroblasts at 72 h, 96 h, and 120 h were significantly lower (1.102 ± 0.027, 1.397 ± 0.039, and 1.527 ± 0.056, respectively) than those observed for the wild-type (WT) controls (1.441±0.029, 1.758 ± 0.043, and 2.003 ± 0.046, respectively). Flow cytometry indicated a decreased G1 cell cycle progression and the accumulation of cells in the S and G2/M phases in GCD2 cells. These accumulations were associated with decreased levels of Cyclin A1, B1, and E1, and increased expression of p16 and p27. p21 and p53 expression was also significantly lower in GCD2 cells compared to the WT. Interestingly, treatment with the autophagy flux inhibitor, bafilomycin A1, resulted in similarly decreased Cyclin A1, B1, D1, and p53 expression in WT fibroblasts. Furthermore, similar findings, including a decrease in Cyclin A1, B1, and D1 and an increase in p16 and p27 expression were observed in autophagy-related 7 (Atg7; known to be essential for autophagy) gene knockout cells. These data provide new insight concerning the role of autophagy in cell cycle arrest and cellular proliferation, uncovering a number of novel therapeutic possibilities for GCD2 treatment.
authors.affiliation: Department of Ophthalmology, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea; Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Seung-Il
authors.initials: SI
authors.lastname: Choi
authors.affiliation: Department of Ophthalmology, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea; Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Shorafidinkhuja
authors.initials: S
authors.lastname: Dadakhujaev
authors.affiliation: Department of Ophthalmology, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea; Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Yong-Sun
authors.initials: YS
authors.lastname: Maeng
authors.affiliation: Department of Ophthalmology, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea; Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: So-Yeon
authors.initials: SY
authors.lastname: Ahn
authors.affiliation: Department of Ophthalmology, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea; Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Tae-Im
authors.initials: TI
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea; Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea; BK21 Plus Project for Medical Science and Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea. Electronic address: eungkkim@yuhs.ac.
authors.forename: Eung Kweon
authors.initials: EK
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D001343:Autophagy; D059447:Cell Cycle Checkpoints; D049109:Cell Proliferation; D002648:Child; D003315:Cornea / Q000166:cytology*; D003317:Corneal Dystrophies, Hereditary / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D006720:Homozygote; D006801:Humans; D018942:Macrolides / Q000737:chemistry; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D018942:Macrolides; C040929:bafilomycin A1
keywords: Cell cycle arrest; Corneal fibroblasts; Cyclin; Defective autophagy flux; Granular corneal dystrophy type 2