Figure 6.

Schematic sketch of conceivable cellular events after exposure to high-glucose ambience and overexpression of Rap1b-GTPase in renal tubular cells. Under high-glucose ambience, there is an activation of protein kinase C (PKC) and generation of ROS that apparently perturb Bcl2–Bax heterodimerization leading to the release of mitochondrial cytochrome C, activation of caspases, fragmentation of DNA, and ultimately apoptosis. Conceivably, upon transfection of GTPase Rap1b, there is a stabilization of Bcl2–Bax and Rap1b–Bcl2 interactions that would inhibit the release of cytochrome C, oxidant stress, DNA fragmentation, and apoptosis.