Previous studies suggested that the RhoA/ROCK pathway may contribute to vascular complications in diabetes. The present study was designed to investigate whether ROCK inhibitor fasudil could prevent high glucose-induced monocyte-endothelial cells adhesion, and whether this was related to fasudil effects on vascular endothelial cell expression of chemotactic factors, vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemoattractant protein-1 (MCP-1).

HUVECs were stimulated with high glucose (HG) or HG + fasudil in different concentration or different time. Monocyte-endothelial cell adhesion was determined using fluorescence-labeled monocytes. The mRNA and protein expression of VCAM-1 and MCP-1 were measured using real-time PCR and western blot. The protein levels of RhoA, ROCKI and p-MYPT were determined using western blot analysis. ELISA was employed to measure the expression of soluble VCAM-1 and MCP-1 in cell supernatants and human serum samples.

Fasudil significantly suppressed HG-induced adhesion of THP-1 to HUVECs. Fasudil reduced Rho/ROCK activity (as indicated by lower p-MYPT/MYPT ratio), and prevented HG induced increases in VCAM-1 and MCP-1 mRNA and protein levels. Fasudil also decreased MCP-1 concentration in HUVEC supernatants, but increased sVCAM-1 shedding into the media. In human diabetic subjects, 2 weeks of fasudil treatment significantly decreased serum MCP-1 level from 27.9 ± 10.6 pg/ml to 13.8 ± 7.0 pg/ml (P < 0.05), while sVCAM-1 increased from 23.2 ± 7.5 ng/ml to 39.7 ± 5.6 ng/ml after fasudil treatment (P < 0.05).

Treatment with the Rho/ROCK pathway inhibitor fasudil attenuated HG-induced monocyte-endothelial cell adhesion, possibly by reducing endothelial expression of VCAM-1 and MCP-1. These results suggest inhibition of Rho/ROCK signaling may have therapeutic potential in preventing diabetes associated vascular inflammation and atherogenesis.