FIGURE 2.

Vpr causes PARP and caspase-3 cleavage in monocytic cells but not in macrophages. Cells were treated with Vpr, mVpr, or staurosporine for 6 h, following which total cell proteins were subjected to Western blotting, and the membranes were probed with anti-PARP (A) or anti-caspase-3 (B) antibodies to evaluate their cleavage as markers of apoptosis. GAPDH was used as a loading control. Based on the densitometric analysis, the bar graphs in the lower panels show the mean ± S.D. (error bars) of cleaved/uncleaved ratios from three experiments in THP1 cells. *, p < 0.05.