Abstract 14929: Reduction of Anti-Angiogenic Spliced Variant VEGF-165b Through SC35 Depletion Augments Angiogenesis in Diabetes

IntroductionDiabetes mellitus is known to increase the risk of cardiovascular disease. These complications are attributed primarily to impaired VEGF-A signalling, resulting in endothelial dysfunction. An inhibitory splice variant of vascular endothelial growth factor A, VEGF165b, has been implicated in several pathologies involving abnormal neovascularization. Splicing factor SC35 favours the splicing of this anti-angiogenic isoform over pro-angiogenic VEGF165a. We sought to examine the effect of SC35 inhibition to reduce VEGF165bexpression and enhance angiogenesis in the diabetic setting.MethodsFirst, SC35 and VEGF165b levelswere quantified in non-diabetic and diabetic human aortic endothelial cells (HAECs and D-HAECs) using qPCR, ELISA, and western blotting in order to assess endothelial dysfunction associated with diabetes. Next, the anti-angiogenic properties of VEGF165b were assessed by treating HAECs with VEGF165aand VEGF165b recombinantproteins. D-HAECs were transfected with either scrambled small interfering RNA (siRNA) or siRNA targeting SC35. Cells underwent Matrigel assay and scratch-wound assay to study the pro-angiogenic effect of SC35 depletion.ResultsmRNA and protein levels of both VEGF165b and SC35 were elevated in D-HAECs. When VEGF165bwas administered to HAECs, there was a marked reduction in tube formation ability (p