Decreased catalase expression and increased susceptibility to oxidative stress in primary cultured corneal fibroblasts from patients with granular corneal dystrophy type II.
Granular corneal dystrophy type II (GCD II) is an autosomal dominant disorder characterized by age-dependent progressive accumulation of transforming growth factor-beta-induced protein (TGFBIp) deposits in the corneal stroma. Several studies have suggested that corneal fibroblasts may decline with age in response to oxidative stress. To investigate whether oxidative stress is involved in the pathogenesis of GCD II, we assayed antioxidant enzymes, oxidative damage, and susceptibility to reactive oxygen species-induced cell death in primary cultured corneal fibroblasts (PCFs) from GCD II patients and healthy subjects. We found elevated protein levels of Mn-superoxide dismutase, Cu/Zn-superoxide dismutase, glutathione peroxidase, and glutathione reductase, as well as increased CAT mRNA and decreased catalase protein in GCD II PCFs. Furthermore, catalase is down-regulated in normal PCFs transfected with transforming growth factor-beta-induced gene-h3. We also observed an increase in not only intracellular reactive oxygen species and H(2)O(2) levels, but also malondialdehyde, 4-hydroxynonenal, and protein carbonyls levels in GCD II PCFs. Greater immunoreactivity for malondialdehyde was observed in the corneal tissue of GCD II patients. In addition, we observed a decrease in Bcl-2 and Bcl-xL levels and an increase in Bax and Bok levels in GCD II PCFs. Finally, GCD II PCFs are more susceptible to H(2)O(2)-induced cell death. Together, these results suggest that oxidative damage induced by decreased catalase is involved in GCD II pathogenesis, and antioxidant agents represent a possible treatment strategy.
Choi
Seung-il
SI
Department of Ophthalmology, Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul, Korea.
Kim
Tae-im
TI
Kim
Kyu Seo
KS
Kim
Bong-Yoon
BY
Ahn
So-yeon
SY
Cho
Hyun-ju
HJ
Lee
Hyung Keun
HK
Cho
Hyun-Soo
HS
Kim
Eung Kweon
EK
D000293:Adolescent; D000328:Adult; D015153:Blotting, Western; D002374:Catalase / Q000096:biosynthesis* / Q000235:genetics; D002478:Cells, Cultured; D002648:Child; D003315:Cornea / Q000201:enzymology / Q000503:physiopathology*; D003317:Corneal Dystrophies, Hereditary / Q000201:enzymology / Q000235:genetics / Q000503:physiopathology*; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis / Q000235:genetics; D005260:Female; D005347:Fibroblasts / Q000201:enzymology / Q000473:pathology*; D005434:Flow Cytometry; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000096:biosynthesis / Q000235:genetics; D055815:Young Adult; D000099222:betaIG-H3 Protein
D002374:Catalase; D016326:Extracellular Matrix Proteins; D006861:Hydrogen Peroxide; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D016212:Transforming Growth Factor beta; D000099222:betaIG-H3 Protein