Role of peroxynitrite in endothelial damage mediated by Cyclosporine A.
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.
Navarro-Antolín
Javier
J
Laboratorio de Investigación Cardiovascular (LICAVA), Hospital Virgen del Rocío, Sevilla, Spain.
Redondo-Horcajo
Mariano
M
Zaragoza
Carlos
C
Alvarez-Barrientos
Alberto
A
Fernández
Ana Patricia
AP
León-Gómez
Elvira
E
Rodrigo
José
J
Lamas
Santiago
S
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
D000975:Antioxidants; D007166:Immunosuppressive Agents; D030421:Peroxynitrous Acid; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D016572:Cyclosporine; D013482:Superoxide Dismutase; D000111:Acetylcysteine