PURPOSE: We have previously shown that 4-hydroxynonenal (4-HNE) causes opacification of cultured rat lenses and that a novel group of glutathione S-transferases (GSTs) exhibit high specific activity towards 4-HNE. Previous studies have shown that t-butylated hydroxy toluene (BHT) induced GSTs in cultured rat lens. Therefore, the purpose of the present studies was to investigate if the opacification of rat lenses exposed to 4-HNE is ameliorated by pre-culturing the lenses in media containing BHT. METHODS: Rat lenses were divided into four groups. Group I and II were controls and groups III and IV were cultured in the presence of 100 microM 4-HNE. Groups II and IV were pre-cultured in the media containing 10 microM BHT for 24 hrs which was designated as 0 time point. Lenses were withdrawn at 24 and 72 h and evaluated for opacification by digital image analysis. Induction of the specific GST isozyme (gammaGST8-8) was studied in the lens epithelium by immunohistochemical studies. Results. Digital image analysis revealed amelioration in opacification induced by 4-HNE, when the lenses were precultured with BHT. Immunohistochemical studies show that BHT induced GST8-8 several folds in the epithelium. CONCLUSIONS: These studies indicate that pretreatment with BHT would increase the lens capacity to detoxify 4-HNE by conjugating it with GSH, thus assigning an important detoxication role to this specific GST isozyme in oxidative cataract.
PURPOSE: We have previously shown that 4-hydroxynonenal (4-HNE) causes opacification of cultured rat lenses and that a novel group of glutathione S-transferases (GSTs) exhibit high specific activity towards 4-HNE. Previous studies have shown that t-butylated hydroxy toluene (BHT) induced GSTs in cultured rat lens. Therefore, the purpose of the present studies was to investigate if the opacification of rat lenses exposed to 4-HNE is ameliorated by pre-culturing the lenses in media containing BHT. METHODS:Rat lenses were divided into four groups. Group I and II were controls and groups III and IV were cultured in the presence of 100 microM 4-HNE. Groups II and IV were pre-cultured in the media containing 10 microM BHT for 24 hrs which was designated as 0 time point. Lenses were withdrawn at 24 and 72 h and evaluated for opacification by digital image analysis. Induction of the specific GST isozyme (gammaGST8-8) was studied in the lens epithelium by immunohistochemical studies. Results. Digital image analysis revealed amelioration in opacification induced by 4-HNE, when the lenses were precultured with BHT. Immunohistochemical studies show that BHT induced GST8-8 several folds in the epithelium. CONCLUSIONS: These studies indicate that pretreatment with BHT would increase the lens capacity to detoxify 4-HNE by conjugating it with GSH, thus assigning an important detoxication role to this specific GST isozyme in oxidative cataract.
Authors: Ngome L Makia; Pasano Bojang; K Cameron Falkner; Daniel J Conklin; Russell A Prough Journal: Chem Biol Interact Date: 2011-01-20 Impact factor: 5.192