FIG 4 .

Silencing JNK and PARP inhibits NADase⁻ SPN-induced mitochondrial depolarization. (A) HeLa cells were treated with siRNA targeting JNK1 and PARP-1 72 h prior to infection with the indicated strains. At 5 h postinfection, cells were stained with TMRE to assess mitochondrial polarization. Data are means and standard errors of the means derived from 2 independent experiments and examination of at least 1,000 total cells and are compared to siRNA-treated but uninfected cells and cells treated with siControl, consisting of a nonspecific siRNA and siGLO, an indicator of transfection efficiency (Dharmacon). **, P < 0.01; ***, P < 0.001.