Figure 5.

The UVB-induced total NAD and NAD+ pool decrease can partially be restored using PARP inhibitor. Prior to UVB irradiation, fibroblasts were incubated 30 min with or without ABT888 (ABT, 20 μM). Cells were then UVB irradiated with 20 kJ/m² (UV) or not (NoUV) in PBS. 6 h post exposition, cells were harvested to quantify NAD/NADH. Same amount of proteins was taken to compare the different conditions, i.e. NoUV CTRL, NoUV ABT, UV CTRL and UV ABT. (a) Concentration of Total NAD and (b) concentration of NADH were measured. Concentration of NAD+ was deduced by subtracting NADH to Total NAD in (c). We found that UVB irradiation significantly reduces total NAD and NAD+, but the use of PARP inhibitor ABT significantly prevent this loss. N = 4, *p-value < 0.05. (d) Schematic representation of the link between NAD+ consumption, PARP1 and the MTS assay.