Antioxidant function of corneal ALDH3A1 in cultured stromal fibroblasts.
Aldehyde dehydrogenase 3A1 (ALDH3A1) is highly expressed in epithelial cells and stromal keratocytes of mammalian cornea and is believed to play an important role in cellular defense. To explore a potential protective role against oxidative damage, a rabbit corneal fibroblastic cell line (TRK43) was stably transfected with the human ALDH3A1 and subjected to oxidative stress induced by H(2)O(2), mitomycin C (MMC), or etoposide (VP-16). ALDH3A1-transfected cells were more resistant to H(2)O(2,) MMC, and VP-16 compared to the vector-transfected cells. All treatments induced apoptosis only in vector-transfected cells, which was associated with increased levels of 4-hydroxy-2-nonenal (4-HNE)-adducted proteins. Treatment with H(2)O(2) resulted in a rise in reduced glutathione (GSH) levels in all groups but was more pronounced in the ALDH3A1-expressing cells. Treatment with the DNA-damaging agents led to GSH depletion in control groups, although the depletion was significantly less in ALDH3A1-expressing cells. Increased carbonylation of ALDH3A1 but not significant decline in enzymatic activity was observed after all treatments. In conclusion, our results suggest that ALDH3A1 may act to protect corneal cells against cellular oxidative damage by metabolizing toxic lipid peroxidation products (e.g., 4-HNE), maintaining cellular GSH levels and redox balance, and operating as an antioxidant.
Lassen
Natalie
N
Molecular Toxicology and Environmental Health Sciences Program, Department of Pharmaceutical Sciences, University of Colorado Health Sciences Center, Denver, CO 80262, USA.
Pappa
Aglaia
A
Black
William J
WJ
Jester
James V
JV
Day
Brian J
BJ
Min
Elysia
E
Vasiliou
Vasilis
V
D000444:Aldehyde Dehydrogenase / Q000378:metabolism*; D000447:Aldehydes / Q000378:metabolism; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology*; D002460:Cell Line; D002470:Cell Survival; D002851:Chromatography, High Pressure Liquid; D003315:Cornea / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004249:DNA Damage / Q000187:drug effects; D005047:Etoposide / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D016685:Mitomycin / Q000494:pharmacology; D018384:Oxidative Stress; D011817:Rabbits; D017154:Stromal Cells / Q000187:drug effects* / Q000378:metabolism; D014162:Transfection
D000447:Aldehydes; D000903:Antibiotics, Antineoplastic; D000975:Antioxidants; D016685:Mitomycin; D005047:Etoposide; C480021:ALDH3A1 protein, human; D000444:Aldehyde Dehydrogenase; D005978:Glutathione; C027576:4-hydroxy-2-nonenal