Figure 2.

Apoptosis, gene expression, morphologic, and GTP activity studies in HK-2 cells exposed to high-glucose ambience. (A) A decrease in the Rap1b GTP activity is observed in a dosage- and time-dependent manner. (B and C) The decrease was associated with an increased expression of Rap1b-GAP, as assessed by real-time PCR. (D and E) High-glucose ambience (35 mM) also induced increased DNA fragmentation and apoptosis, which were reduced with the transfection of HK-2 cells with Rap1b-pcDNA. (F) The overexpression of full-length Rap1b-pcDNA (FL) normalized the altered expression of Bcl-2 and Bax, whereas transfection with Rap1b mutant constructs (M17 and M61) failed to correct the expression. F-g reflects quantification of Bcl-2/Bax ratio of the band density from four Western blots. **P < 0.001.