Nitric oxide preconditioning regulates endothelial monolayer integrity via the heat shock protein 90-soluble guanylate cyclase pathway.
Large (pathological) amounts of nitric oxide (NO) induce cell injury, whereas low (physiological) NO concentrations often ameliorate cell injury. We tested the hypotheses that pretreatment of endothelial cells with low concentrations of NO (preconditioning) would prevent injury induced by high NO concentrations. Apoptosis, induced in bovine aortic endothelial cells (BAECs) by exposing them to either 4 mM sodium nitroprusside (SNP) or 0.5 mM N-(2-aminoethyl)-N-(2-hydroxy-2-nitrosohydrazino)-1,2-ethylenediamine (spermine NONOate) for 8 h, was abolished by 24-h pretreatment with either 100 microM SNP, 10 microM spermine NONOate, or 100 microM 8-bromo-cGMP (8-Br-cGMP). Repair of BAECs following wounding, measured as the recovery rate of transendothelial electrical resistance, was delayed by 8-h exposure to 4 mM SNP, and this delay was significantly attenuated by 24-h pretreatment with 100 microM SNP. NO preconditioning produced increased association and expression of soluble guanyl cyclase (sGC) and heat shock protein 90 (HSP90). The protective effect of NO preconditioning, but not the injurious effect of 4 mM SNP, was abolished by either a sGC activity inhibitor 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ) or a HSP90 binding inhibitor (radicicol) and was mimicked by 8-Br-cGMP. We conclude that preconditioning with a low dose of NO donor accelerates repair and maintains endothelial integrity via a mechanism that includes the HSP90/sGC pathway. HSP90/sGC may thus play a role in the protective effects of NO-generating drugs from injurious stimuli.
Antonova
Galina N
GN
Vascular Biology Center, Medical College of Georgia, Augusta, GA, 30912-2500, USA. gantonova@mail.mcg.edu
Snead
Connie M
CM
Antonov
Alexander S
AS
Dimitropoulou
Christiana
C
Venema
Richard C
RC
Catravas
John D
JD
D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D002417:Cattle; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D017869:Cyclic GMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D004305:Dose-Response Relationship, Drug; D017097:Electric Impedance; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology; D010069:Oxadiazoles / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D018160:Receptors, Cytoplasmic and Nuclear / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000071756:Soluble Guanylyl Cyclase; D013096:Spermine / Q000031:analogs & derivatives / Q000494:pharmacology; D013997:Time Factors; D014945:Wound Healing / Q000187:drug effects*
C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D004791:Enzyme Inhibitors; D018841:HSP90 Heat-Shock Proteins; D020030:Nitric Oxide Donors; D010069:Oxadiazoles; D011810:Quinoxalines; D018160:Receptors, Cytoplasmic and Nuclear; C091861:spermine nitric oxide complex; D009599:Nitroprusside; D013096:Spermine; C016276:8-bromocyclic GMP; D009569:Nitric Oxide; D017869:Cyclic GMP-Dependent Protein Kinases; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase; D006152:Cyclic GMP