LR-90 prevents methylglyoxal-induced oxidative stress and apoptosis in human endothelial cells

Abstract

Methylglyoxal (MGO) is a highly reactive dicarbonyl compound known to induce cellular injury and cytoxicity, including apoptosis in vascular cells. Vascular endothelial cell apoptosis has been implicated in the pathophysiology and progression of atherosclerosis. We investigated whether the advanced glycation end-product inhibitor LR-90 could prevent MGO-induced apoptosis in human umbilical vascular endothelial cells (HUVECs). HUVECs were pre-treated with LR-90 and then stimulated with MGO. Cell morphology, cytotoxicity and apoptosis were evaluated by light microscopy, MTT assay, and Annexin V-FITC and propidium iodide double staining, respectively. Levels of Bax, Bcl-2, cytochrome c, mitogen-activated protein kinases (MAPKs) and caspase activities were assessed by Western blotting. Reactive oxygen species (ROS) generation and mitochondrial membrane potential (MMP) were measured with fluorescent probes. LR-90 dose-dependently prevented MGO-associated HUVEC cytotoxicity and apoptotic biochemical changes such as loss of MMP, increased Bax/Bcl-2 protein ratio, mitochondrial cytochrome c release and activation of caspase-3 and 9. Additionally, LR-90 blocked intracellular ROS formation and MAPK (p44/p42, p38, JNK) activation, though the latter seem to be not directly involved in MGO-induced HUVEC apoptosis. LR-90 prevents MGO-induced HUVEC apoptosis by inhibiting ROS and associated mitochondrial-dependent apoptotic signaling cascades, suggesting that LR-90 possess cytoprotective ability which could be beneficial in prevention of diabetic related-atherosclerosis.

Glyoxalase 1-knockdown in human aortic endothelial cells – effect on the proteome and endothelial function estimates

“…were able to show that in human umbilical vascular endothelial cells direct stimulation with 0.4 mM MG induced apoptosis and increased caspase 3 and caspase 9 cleavage after an incubation period of 24 h. This effect was reversible by preincubation with an AGE-inhibitor (LR90)47. The MG concentrations used in this assay are 1000fold higher than observed in our assays after 72 h of Glo1-knockdown (Fig.…”

Methylglyoxal suppresses human colon cancer cell lines and tumor growth in a mouse model by impairing glycolytic metabolism of cancer cells associated with down-regulation of c-Myc expression

“…15 Moreover, AG abolished the MG-induced anti-tumor effects by acting as a scavenger, reacting rapidly with MG. 30 Cancer cells favor the aerobic glycolytic pathway and generate energy predominantly by increasing their rate of glycolysis. 24 MG is an intermediate metabolite of glucose.…”

Methylglyoxal and methylglyoxal‐modified collagen as inducers of cellular injury in gingival connective tissue cells

“…MGO may induce apoptosis in several cell types, including human blood mononuclear cells, human endothelial cells, blastocysts and hepatic Hepg2 cells . Moreover, reactive oxygen species have been identified in the induction of cell death by MGO .…”

“…It is important to consider that besides the pathological modification of extracellular matrix proteins, MGO may directly affect cell viability and function in several cell types . Nevertheless, the potential cytotoxic effects of MGO on periodontal cells remain largely undefined.…”