Figure 1

Increased oxidative stress in mutant mouse embryonic fibrobasts. (A) ROS levels in wild type and Wrn^Δhel/Δhelcells determined by measuring the intensity of fluorescence by 2',7'-dichlrofluorescein per μg of protein in cells. Asterisks denote statistical significance compared to wild type cells (*t-test: P < 0.05). (B) Oxidative DNA lesions created by ROS in wild type and Wrn^Δhel/Δhelcell cultures. The number of abasic sites per pg of genomic DNA was detected as described in Materials and Methods. The asterisk denotes statistical significance compared to wild type cells (*t-test: P < 0.05). (C) ATP levels in wild type and Wrn^Δhel/Δhelcells. Asterisks denote statistical significance compared to wild type cells (*t-test: P < 0.05). (D) ADP/ATP ratios in wild type and Wrn^Δhel/Δhelcells. Asterisks denote statistical significance compared to wild type cells (*t-test: P < 0.05). (E) Inner mitochondrial transmembrane potential in wild type and Wrn^Δhel/Δhelcells. Mitochondrial membrane potential was measured with the potentiometric dye TMRE. Asterisks denote statistical significance compared to wild type cells (*t-test: P < 0.03). All experiments in this figure were performed in quadruplicate.