Figure 5. Silencing proautophagic molecules increased GRP secretion and tubule formation by HUVECs. (A) ATG5 or BECN1 silencing and LC3-II was determined by immunoblotting using lysates from BE(2)-C and BE(2)-M17 cells treated with siRNA against ATG5 or BECN1. ACTB was probed to monitor equal loading. (B) BE(2)-C and BE(2)-M17 cells transfected with siATG5 or siBECN1 were plated on 100 mm dishes in serum-free medium for 48 h, and GRP secretion was measured by ELISA. (C) HUVECs were plated on 24-well plates coated with Matrigel and incubated with or without GRP antibody (GRP Ab; 1 μg/mL) with cell culture media from BE(2)-C or BE(2)-M17 cells transfected with siNTC, siATG5 or siBECN1. Tubule staining was performed in triplicate. Values shown are mean ± SEM of three separate experiments (*P < 0.05 vs. siNTC or without GRP Ab).