Nitrotyrosine impairs angiogenesis and uncouples eNOS activity of pulmonary artery endothelial cells isolated from developing sheep lungs.
Infection is known to impair the growth of developing lungs. It is known that plasma free nitrotyrosine (NT) levels can reach 150 μM during sepsis. Free NT incorporates into microtubules and impairs cell function. We hypothesize that free NT perturbs the angiogenic activity of pulmonary artery endothelial cells (PAEC) in developing lungs. PAEC from fetal lamb lungs were incubated with NT (1-100 μM). We examined the effects of NT on tube formation, cell proliferation, apoptosis, and α-tubulin assembly in PAEC. We assessed superoxide anion (O2) and NO levels in PAEC during NT exposure. Effects of NT on endothelial NO synthase (eNOS) were examined with respect to eNOS-dimer formation and the association of eNOS chaperone, heat-shock-protein-90 (hsp90). NT decreased tube formation and increased apoptosis in PAEC. NT also decreased NO levels, increased NOS-dependent O2 generation, and promoted α-tubulin depolymerization. Although NT increased eNOS homodimer formation, it decreased the hsp90 association with eNOS. Our data suggest that increased NT formation during sepsis may uncouple eNOS activity and increase oxidative stress. Because NO plays an important role in angiogenesis and vasodilation, these observations suggest a mechanism for the impaired vasodilation and angiogenesis during sepsis in the developing lung.
Department of Pediatrics, Medical College of Wisconsin, Wauwatosa, Wisconsin 53226, USA.
Ru-Jeng
RJ
Teng
Tzong-Jin
TJ
Wu
C Gaston
CG
Bisig
Annie
A
Eis
Kirkwood A
KA
Pritchard
Girija G
GG
Konduri
D000818:Animals; D017209:Apoptosis; D049109:Cell Proliferation; D002478:Cells, Cultured; D002585:Cesarean Section; D042783:Endothelial Cells / Q000201:enzymology* / Q000473:pathology; D005865:Gestational Age; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D008168:Lung / Q000098:blood supply* / Q000201:enzymology* / Q000254:growth & development; D008870:Microtubules / Q000378:metabolism; D018919:Neovascularization, Physiologic; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D047928:Premature Birth; D055503:Protein Multimerization; D011651:Pulmonary Artery / Q000201:enzymology* / Q000254:growth & development / Q000473:pathology; D018805:Sepsis / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D012756:Sheep; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism
D018841:HSP90 Heat-Shock Proteins; D014404:Tubulin; D013481:Superoxides; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D052250:Nitric Oxide Synthase Type III; D013482:Superoxide Dismutase