Glucagon–like peptide–1 protects against cardiac microvascular endothelial cells injured by high glucose

ObjectiveTo investigate the protective effect of glucagon–like peptid–1 (GLP–1) against cardiac microvascular endothelial cell (CMECs) injured by high glucose.MethodsCMECs were isolated and cultured. Superoxide assay kit and dihydroethidine (DHE) staining were used to assess oxidative stress. TUNEL staining and caspase 3 expression were used to assess the apoptosis of CMECs. H89 was used to inhibit cAMP/PKA pathway; fasudil was used to inhibit Rho/ROCK pathway. The protein expressions of Rho, ROCK were examined by Western blot analysis.ResultsHigh glucose increased the production of ROS, the activity of NADPH, the apoptosis rate and the expression level of Rho/ROCK in CMECs, while GLP–1 decreased high glucose–induced ROS production, the NADPH activity and the apoptosis rate and the expression level of Rho/ROCK in CMECs, the difference were statistically significant (P<0.05).ConclusionsGLP–1 could protect the cardiac microvessels against oxidative stress and apoptosis. The protective effects of GLP–1 are dependent on downstream inhibition of Rho through a cAMP/PKA–dependent manner, resulting in a subsequent decrease in the expression of NADPH oxidase.