title: Altered mitochondrial function in type 2 granular corneal dystrophy.
abstract: Type 2 granular corneal dystrophy (GCD2) is caused by point mutation R124H in the transforming growth factor-β-induced gene (TGFBI) and is characterized by age-dependent progression of corneal deposits. Mitochondrial features in heterozygous GCD2 and normal corneal tissues was evaluated using electron microscopy. Primary corneal fibroblasts of homozygous and normal corneas were cultured to passage 4 or 8. Keratocytes of normal corneal tissue are narrow, and details of their intracellular organelles are difficult to distinguish. Keratocytes of heterozygous GCD2 tissues exhibited many degenerative mitochondria. MitoTracker and cytochrome c staining demonstrated increased mitochondrial activity in mutated cells at early passages. Decreases in depolarized mitochondria, cellular proliferation, and expression of complexes I to V and increases in apoptotic change were observed in late-passage mutant fibroblasts. PGC-1α, ANT-1, p-Akt, and p-mTOR but not NF-κB expression demonstrated a passage-dependent decrease in all cells. Increased passage- or mutation-related intracellular reactive oxygen species and delayed proliferation of methanethiosulfonate (MTS) were recovered using application of antioxidant butylated hydroxyanisole. Mitochondrial features and function were altered in mutated GCD2 keratocytes, in particular in older cells. Alteration of mitochondrial function is critical for understanding the pathogenesis of GCD2.
authors.affiliation: Corneal Dystrophy Research Institute, the Department of Ophthalmology, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Tae-im
authors.initials: TI
authors.lastname: Kim
authors.forename: Hanna
authors.initials: H
authors.lastname: Kim
authors.forename: Doo Jae
authors.initials: DJ
authors.lastname: Lee
authors.forename: Seung-Il
authors.initials: SI
authors.lastname: Choi
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Kang
authors.forename: Eung Kweon
authors.initials: EK
authors.lastname: Kim
mesh_terms: D000818:Animals; D003317:Corneal Dystrophies, Hereditary / Q000235:genetics*; D045304:Cytochromes c / Q000378:metabolism; D018450:Disease Progression; D005347:Fibroblasts / Q000378:metabolism; D006579:Heterozygote; D006720:Homozygote; D015603:Keratinocytes / Q000166:cytology; D008564:Membrane Potentials; D051379:Mice; D046529:Microscopy, Electron, Transmission / Q000379:methods; D008928:Mitochondria / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism; D009154:Mutation; D017354:Point Mutation; D017382:Reactive Oxygen Species; D053773:Transforming Growth Factor beta1 / Q000235:genetics
chemical_list: D017382:Reactive Oxygen Species; D053773:Transforming Growth Factor beta1; D045304:Cytochromes c