Fig. 1
From: TriPer, an optical probe tuned to the endoplasmic reticulum tracks changes in luminal H2O2
Glutathione depletion sensitizes pancreatic β-cells to endogenous H2O2. a Absorbance at 540 nm (an indicator of cell mass) by cultures of a β-cell line (RINm5F) or mouse embryonic fibroblasts (MEFs, a reference) that had been exposed to the indicated concentration of buthionine sulfoximine (BSO) before fixation and staining with crystal violet. b Plot of in vitro catalase activity, reflected in time-dependent decline in absorbance (A 240 nm) of H2O2 solution, exposed to lysates of untransfected RINm5F cells (-) or cells stably transfected with plasmids encoding cytoplasmic (CAT cyto) or ER-localized catalase (CAT ER). c As in (a), comparing untransfected RINm5F cells (-) or cells stably expressing cytosolic catalase (CAT cyto). d Fluorescent photomicrographs of RINm5F cells stably expressing a tetracycline inducible human pro-insulin gene (RINm5FTetON-Ins) fixed at the indicated time points post doxycycline (20 ng/ml) exposure and immunostained for total insulin (red channel); Hoechst 33258 was used to visualize cell nuclei (blue channel). e As in (a), comparing cell mass of uninduced and doxycycline-induced RINm5FTetON-Ins cells that had or had not been transfected with an expression plasmid encoding ER catalase (CAT ER). Shown are mean +/– standard error of the mean (SEM), n ≥ 3