High glucose increases expression of cyclooxygenase-2, increases oxidative stress and decreases the generation of nitric oxide in mouse microvessel endothelial cells.
Hyperglycaemia is a key factor that contributes to the development of diabetes-related microvascular disease. Both cyclooxygenase I and cyclooxygenase II are expressed in endothelial cells and play key roles in the regulation of cardiovascular function. In the current study we tested the hypothesis that hyperglycaemia-induced increased expression of cyclooxygenase II is a contributing factor both to the increased oxidative stress and to the reduction in the generation of nitric oxide in microvessel endothelial cells following their exposure to high glucose. We demonstrated that the exposure of mouse microvascular endothelial cells to high glucose for 3 days decreased the generation of nitric oxide and enhanced production of superoxide. Western blots illustrated that exposure to high glucose also increased endothelial nitric oxide synthase and cyclooxygenase II protein expression levels and decreased the dimer/monomer ratio of endothelial nitric oxide synthase protein. All the changes induced by the high glucose culture media could be reversed by either the cyclooxygenase II inhibitor CAY10404, the non-selective cyclooxygenase inhibitor indomethacin or the protein kinase C inhibitor chelerythrine, but not solely by preincubation with the antioxidant and putative NADPH oxidase inhibitor, apocynin. Our data indicate that high glucose induced oxidative stress is linked to an increase in the expression of cyclooxygenase II and a reduced generation of nitric oxide that is associated with an uncoupled endothelial nitric oxide synthase, possibly due to decreased dimer/monomer ratio.
Aljofan
Mohamad
M
School of Medical Sciences, RMIT University, Victoria, Australia.
Ding
Hong
H
D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D053119:Benzophenanthridines / Q000494:pharmacology; D015153:Blotting, Western; D002478:Cells, Cultured; D051545:Cyclooxygenase 1 / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology; D015536:Down-Regulation; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology*; D005947:Glucose / Q000378:metabolism*; D006943:Hyperglycemia / Q000201:enzymology*; D007213:Indomethacin / Q000494:pharmacology; D007555:Isoxazoles / Q000494:pharmacology; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D055806:Microvessels / Q000201:enzymology; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000378:metabolism; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D055503:Protein Multimerization; D013450:Sulfones / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism; D013997:Time Factors; D015854:Up-Regulation
C501048:3-(4-methylsulfonylphenyl)-4-phenyl-5-trifluoromethylisoxazole; D000098:Acetophenones; D053119:Benzophenanthridines; D052246:Cyclooxygenase 2 Inhibitors; D007555:Isoxazoles; D008565:Membrane Proteins; D047428:Protein Kinase Inhibitors; D013450:Sulfones; D013481:Superoxides; D009569:Nitric Oxide; C056165:acetovanillone; C016299:chelerythrine; D052250:Nitric Oxide Synthase Type III; C496315:Nos3 protein, mouse; C077623:Ptgs2 protein, mouse; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496512:Ptgs1 protein, mouse; D019255:NADPH Oxidases; D011493:Protein Kinase C; D005947:Glucose; D019331:NG-Nitroarginine Methyl Ester; D007213:Indomethacin