Ascorbate reverses high glucose- and RAGE-induced leak of the endothelial permeability barrier.
High glucose concentrations due to diabetes increase leakage of plasma constituents across the endothelial permeability barrier. We sought to determine whether vitamin C, or ascorbic acid (ascorbate), could reverse such high glucose-induced increases in endothelial barrier permeability. Human umbilical vein endothelial cells and two brain endothelial cell lines cultured at 25 mM glucose showed increases in endothelial barrier permeability to radiolabeled inulin compared to cells cultured at 5mM glucose. Acute loading of the cells for 30-60 min with ascorbate before the permeability assay prevented the high glucose-induced increase in permeability and decreased basal permeability at 5mM glucose. High glucose-induced barrier leakage was mediated largely by activation of the receptor for advanced glycation end products (RAGE), since it was prevented by RAGE blockade and mimicked by RAGE ligands. Intracellular ascorbate completely prevented RAGE ligand-induced increases in barrier permeability. The high glucose-induced increase in endothelial barrier permeability was also acutely decreased by several cell-penetrant antioxidants, suggesting that at least part of the ascorbate effect could be due to its ability to act as an antioxidant.
Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232-0475, United States.
M Elizabeth
ME
Meredith
Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232-0475, United States.
Zhi-Chao
ZC
Qu
Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232-0475, United States; Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232-0475, United States. Electronic address: james.may@vanderbilt.edu.
James M
JM
May
D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001205:Ascorbic Acid / Q000378:metabolism / Q000494:pharmacology*; D001549:Benzamides / Q000494:pharmacology; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000187:drug effects; D002478:Cells, Cultured; D002839:Chromans / Q000494:pharmacology; D003497:Cyclic N-Oxides / Q000494:pharmacology; D004229:Dithiothreitol / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology*; D017127:Glycation End Products, Advanced / Q000494:pharmacology; D024243:HMGB1 Protein / Q000494:pharmacology; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D051379:Mice; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D013113:Spin Labels
D000975:Antioxidants; D001549:Benzamides; D002839:Chromans; D003497:Cyclic N-Oxides; C572629:FPS-ZM1; D017127:Glycation End Products, Advanced; D024243:HMGB1 Protein; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic; D013113:Spin Labels; C081628:advanced glycation end products-bovine serum albumin; D012710:Serum Albumin, Bovine; D005947:Glucose; D001205:Ascorbic Acid; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid; D004229:Dithiothreitol; C001803:tempol; D000111:Acetylcysteine
Ascorbate; Endothelial permeability; High glucose; Oxidative stress; RAGE