Figure 3.

SUMO1 overexpression stabilizes HIF-1α protein and partially restores vascular morphology. SUMO1, ubiquitin, HIF-1α and VEGF protein expression levels were (A) investigated by western blotting and (B) normalized to those of β-actin following exposure of HUVECs transfected with SUMO1 gene or empty plasmid (control) transfection to normoxia or hypoxia for 7 days. (C) Angiogenic potential was examined via simulated angiogenesis experiments (scale bar, 20 µm). (D) Number of complete vascular lumens and (E) vessel wall thickness were measured. (F) LDH content was measured via ELISA following exposure of SUMO1- and empty control-transfected HUVECs to normoxia or hypoxia for 7 days. Data are presented as the mean ± standard deviation. n=3. *P<0.05 vs. control. SUMO1, small ubiquitin-related modifier 1; HIF, hypoxia inducible factor; VEGF, vascular endothelial growth factor; HUVEC, human umbilical vein endothelial cells; LDH, lactate dehydrogenase.