Figure 1.

The OGT/O-GlcNAc axis regulates VEGF expression by the O-GlcNAc modification of SP-1. (A) Representative Immunoblots of VEGF and β-Actin from IPAH PASMCs and PAECs following 5 or 25 mM glucose administration as described in the Methods section. (B) PAECs were transfected with scramble or OGT siRNA. OGT and VEGF expression was determined by Immunoblot analysis and quantitated (C). Immunoprecipitation was performed using 1 g of a PAEC lysate following different glucose concentrations as described in the methods (D) or IP in the presence or absence of OGT inhibitor (Inh) (E). The samples were incubated with O-GlcNAc antibody followed by addition of protein L beads, SDS-PAGE, and Western blot analysis. (F) A representative Western blot of SP1 and VEGF following SP1 gene silencing using siRNA in the presence of different glucose concentrations. Error bars indicate standard error of the mean (SEM). * p < 0.05 and ** p < 0.01.