Edaravone Protected Human Brain Microvascular Endothelial Cells from Methylglyoxal-Induced Injury by Inhibiting AGEs/RAGE/Oxidative Stress

Abstract

Subjects with diabetes experience an increased risk of cerebrovascular disease and stroke compared with nondiabetic age-matched individuals. Increased formation of reactive physiological dicarbonyl compound methylglyoxal (MGO) seems to be implicated in the development of diabetic vascular complication due to its protein glycation and oxidative stress effect. Edaravone, a novel radical scavenger, has been reported to display the advantageous effects on ischemic stroke both in animals and clinical trials; however, little is known about whether edaravone has protective effects on diabetic cerebrovascular injury. Using cultured human brain microvascular endothelial cells (HBMEC), protective effects of edaravone on MGO and MGO enhancing oxygen-glucose deprivation (OGD) induced injury were investigated. Cell injury was measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) formation, cell account, lactate dehydrogenase (LDH) release and Rhodamine 123 staining. Advanced glycation end-products (AGEs) formation and receptor for advanced glycation end-products (RAGE) expression were measured by western blotting. Cellular oxidative stress was measured by reactive oxygen species (ROS) release. Treatment of MGO for 24 h significantly induced HBMEC injury, which was inhibited by pretreatment of edaravone from 10–100 µmol/l. What’s more, treatment of MGO enhanced AGEs accumulation, RAGE expression and ROS release in the cultured HBMEC, which were inhibited by 100 µmol/l edaravone. Finally, treatment of MGO for 24 h and then followed by 3 h OGD insult significantly enhanced cell injury when compared with OGD insult only, which was also protected by 100 µmol/l edaravone. Thus, edaravone protected HBMEC from MGO and MGO enhancing OGD-induced injury by inhibiting AGEs/RAGE/oxidative stress.

Protection of the blood-brain barrier under pathological conditions

“…We could see a concentration-and time-dependent effect based on kinetic data from impedance measurements. Our data are in agreement with viability studies on the effect of edaravone pretreatment against methylglyoxal-induced toxicity (Li et al, 2013c).…”

“…Elevated level of ROS weakens the barrier integrity , however the contribution of methylglyoxaltriggered ROS production in the increased endothelial permeability is controversial (Li et al, 2013b). In the present study we confirmed that methylglyoxal treatment promotes oxidative stress in brain endothelial cells, similarly to previous results on endothelial cells (Li et al, 2013b;Li et al, 2013c) and other cellular systems . The kinetics of ROS production helped to determine the optimal time point for protection assays and other experiments: the 4 h time point, where ROS formation was still elevated, was purposefully selected.…”

“…Impedance data reflecting changes in cell adhesion, shape and number were confirmed by MTT tests measuring the metabolic activity of cells. Our data lend support to and expand previous findings on the effect of methylglyoxal on human brain endothelial cells Li et al, 2013a;Li et al, 2013b;Li et al, 2013c). We selected the human hCMEC/D3 cell line as a simplified model of the BBB.…”

“…Its antioxidant effect was observed in our experiment, too. In a recent independent study edaravone suppressed methyglyoxalinduced ROS production in human brain endothelial cells by two possible mechanisms (Li et al, 2013c). Pre-treatment with edaravone decreased methylglyoxal-induced AGE accumulation and activation of its receptor RAGE (Li XH et al, 2013), and the subsequent production of ROS .…”

“…In a recent study, edaravone reduced cell injury in oxygen-glucose deprivation in vitro model. Edaravone pretreatment attenuated methylglyoxal-induced decrease in cell viability of brain endothelial cells (Li et al 2013c). In our study co-treatment with edaravone provided a complete protection against the toxic effect of methylglyoxal (Fig.…”