Figure 7. Knockdown of PKCδ improves insulin-induced VEGF secretion.

(A) Fluorescence micrographic images of adenoviral vector containing GFP (Ad-GFP) and dominant-negative PKCδ–infected (Ad-dnPKCδ) Medalist fibroblasts. Representative immunoblot of PKCδ (B), p-AKT after stimulation with insulin for 10 minutes (C), and VEGF protein levels after stimulation with 100 nM insulin for 16 hours (D) in Medalist fibroblasts infected with Ad-GFP or Ad-dnPKCδ. Representative immunoblot of PKCδ (E) and VEGF protein levels (F) in Medalist fibroblasts transfected with siRNA and stimulated with 100 nM insulin for 16 hours. Representative immunoblot of PKCδ (G), p-AKT after stimulation with 100 nM insulin for 10 minutes (H), and VEGF protein levels (I) after stimulation with 100 nM insulin for 16 hours in control fibroblasts infected with Ad-GFP or Ad-wtPKCδ. Data represent the mean ± SD. n = 10 in Medalist experiments and n = 7 in the control experiments. The criteria for selecting the cell lines for these experiments were completely random, and the clinical and demographic characteristics of the selected subjects did not differ from those of the rest of the patients. A Student’s t or χ² test was used for 2-way comparisons based on the distribution and number of observations of the variable.