CATALASE TRANSFECTION DECREASES HYDROGEN-PEROXIDE TOXICITY IN A PANCREATIC BETA-CELL LINE

BetaTC6-F7 cells like normal Beta cells were found to be highly sensit ive to hydrogen peroxide and to possess very low levels of catalase. T herefore we tested whether overexpression of catalase could enhance re sistance to hydrogen peroxide. Enzyme activity was increased forty fol d by transient transfection of a catalase transgene. To assess protect ion from hydrogen peroxide a cotransfection method using a human growt h hormone reporter gene was developed. Human growth hormone secretion was shown to be a suitable marker for insulin secretion since both hor mones demonstrated virtually identical glucose dose response curves. C atalase transfection was found to provide significant protection again st hydrogen peroxide indicating that low catalase may contribute to th e sensitivity of cells to hydrogen peroxide.