Differential effects of PCBs on the induction of apoptosis machinery and PKCα translocation in rat renal tubular cell cultures

Aroclor 1248 (a commercial PCB mixture with 48% chlorine by weight), PCB 153 (2,2′,4,4′,5,5′-hexachlorobiphenyl, a di-ortho-substituted nonplanar congener) and PCB 77 (3,3′,4,4′-tetrachlorobiphenyl, a non-ortho-substituted planar congener), significantly increased PKCα activity compared to control cells in the cytosolic and particulate cell fractions, and increased the PKCα protein content in the particulate fraction. The nonplanar PCB 153 showed stronger effects than the coplanar congener PCB 77. In addition, Aroclor 1248 decreased both, procaspase-3 levels and the Bcl-2/Bax protein ratio. These findings indicate that PCBs, particularly nonplanar congeners, can induce apoptosis in primary renal tubular cells through the PKCα, caspase-3 and Bcl-2/Bax pathway.