O R I G I N a L I N V E S T I G a T I O N Open Access the Role of Profilin-1 in Endothelial Cell Injury Induced by Advanced Glycation End Products (ages)

Background: Accumulation of advanced glycation end products (AGEs) in the vasculature triggers a series of morphological and functional changes contributing to endothelial hyperpermeability. The reorganisation and redistribution of the cytoskeleton regulated by profilin-1 mediates endothelial cell contraction, which results in vascular hyperpermeability. This study aimed to investigate the pivotal role of profilin-1 in the process of endothelial cell damage induced by AGEs. Methods: Human umbilical vein endothelial cells (HUVECs) were incubated with AGEs. The mRNA and protein expression of profilin-1 was determined using real-time PCR and western blotting analyses. The levels of intercellular adhesion molecule-1 (ICAM-1), nitric oxide (NO) and reactive oxygen species (ROS), as well as the activities of nuclear factor-κB (NF-κB) and protein kinase C (PKC), were detected using the appropriate kits. The levels of asymmetric dimethylarginine (ADMA) were determined using HPLC. The distribution of the cytoskeleton was visualised using immunofluorescent staining. Results: Compared with the control, incubation of endothelial cells with AGEs (200 μg/ml) for 4 or 24 h significantly up-regulated the mRNA and protein expression of profilin-1, markedly increased the levels of ICAM-1 and ADMA and decreased the production of NO (P<0.05, P<0.01), which was significantly attenuated by pretreatment with DPI (an antioxidant), GF 109203X (PKC inhibitor) or BAY-117082 (NF-κB inhibitor). DPI (10 μmol/L) markedly decreased the elevated levels of ROS induced by AGEs (200 μg/ml, 24 h); however, GF 109203X (10 μmol/L) and BAY-117082 (5 μmol/L) exhibited no significant effect on the formation of ROS by AGEs. Immunofluorescent staining indicated that AGEs markedly increased the expression of profilin-1 in the cytoplasm and the formation of actin stress fibres, resulting in the rearrangement and redistribution of the cytoskeleton. Disruption of profilin-1 gene expression attenuated the extent of endothelial abnormalities by reducing ICAM-1 and ADMA levels and elevating NO levels (P<0.05, P<0.01), but this disruption had no effect on the activities of NF-κB and PKC (P>0.05).