title: Role of peroxynitrite in endothelial damage mediated by Cyclosporine A.
abstract: Although Cyclosporine A (CsA) is an effective therapy for immunosuppression, its use encompasses serious side effects that have been associated with oxidative stress. We previously reported the intracellular formation of both peroxynitrite and 3-nitrotyrosine in cultured bovine aortic endothelial cells (BAEC) when exposed to CsA. Here we show that re-addition of CsA to BAEC increases peroxynitrite formation in a concentration-dependent manner. This effect is inhibited by the glutathione donor and antioxidant, N-acetylcysteine (NAC). BAEC exposed to CsA showed impaired integrity of plasma membranes and increased cytolysis, a phenomenon prevented by NAC. When CsA was administered to mice, the increased presence of 3-nitrotyrosine was detected in the aortic endothelium, an effect also abrogated by the concomitant administration of NAC. An increase in nitrated MnSOD was detected in BAEC treated with CsA and the peroxynitrite donor SIN-1 and recapitulated in recombinant MnSOD, exposed to the conditioned media from BAEC. We propose that CsA promotes nitration of specific molecular targets, such as MnSOD, within vascular endothelial cells. This may represent a pathogenetic mechanism of vascular injury. Inhibition of this process by clinically applicable antioxidants, such as NAC, lends a basis for the exploration of therapeutic alternatives in patients treated with CsA.
authors.affiliation: Laboratorio de Investigación Cardiovascular (LICAVA), Hospital Virgen del Rocío, Sevilla, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Navarro-Antolín
authors.forename: Mariano
authors.initials: M
authors.lastname: Redondo-Horcajo
authors.forename: Carlos
authors.initials: C
authors.lastname: Zaragoza
authors.forename: Alberto
authors.initials: A
authors.lastname: Alvarez-Barrientos
authors.forename: Ana Patricia
authors.initials: AP
authors.lastname: Fernández
authors.forename: Elvira
authors.initials: E
authors.lastname: León-Gómez
authors.forename: José
authors.initials: J
authors.lastname: Rodrigo
authors.forename: Santiago
authors.initials: S
authors.lastname: Lamas
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001011:Aorta / Q000166:cytology; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D016572:Cyclosporine / Q000009:adverse effects*; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D007166:Immunosuppressive Agents / Q000009:adverse effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D009569:Nitric Oxide / Q000378:metabolism; D030421:Peroxynitrous Acid / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D000975:Antioxidants; D007166:Immunosuppressive Agents; D030421:Peroxynitrous Acid; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D016572:Cyclosporine; D013482:Superoxide Dismutase; D000111:Acetylcysteine