title: HSP90 and Akt modulate Ang-1-induced angiogenesis via NO in coronary artery endothelium.
abstract: This study examines the notion that heat shock protein (HSP) 90 binding to nitric oxide (NO), endothelial NO synthase (eNOS), and PI3K-Akt regulate angiopoietin (Ang)-1-induced angiogenesis in porcine coronary artery endothelial cells (PCAEC). Exposure to Ang-1 (250 ng/ml) for periods up to 2 h resulted in a time-dependent increase in eNOS phosphorylation at Ser 1177 that occurred by 5 min and peaked at 60 min. This was accompanied by a gradual increase in NO release. Ang-1 also led to stimulation of HSP90 binding to eNOS and a significant increase in Akt phosphorylation. Thirty minutes of pretreatment of cells with either 1 microg/ml geldanamycin (a specific inhibitor of HSP90) or 500 nM wortmannin [a specific phosphatidylinositol 3 (PI3)-kinase (PI3K) inhibitor] significantly attenuated Ang-1-stimulated eNOS phosphorylation and NO production. Exposure to Ang-1 caused an increase in endothelial cell migration, tube formation, and sprouting from PCAEC spheroids, and pharmacological blockage of HSP90 function or inhibition of PI3K-Akt pathway completely abolished these effects. Inhibition of nitric oxide synthase by NG-nitro-l-arginine methyl ester (2.5 mM) also resulted in a significant decrease in Ang-1-induced angiogenesis. We conclude that stimulated HSP90 binding to eNOS and activation of the PI3-Akt pathway contribute to Ang-1-induced eNOS phosphorylation, NO production, and angiogenesis in PCAEC.
authors.affiliation: Department of Pathology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2650, USA.
authors.forename: Jian-xiong
authors.initials: JX
authors.lastname: Chen
authors.forename: Mayme Lee
authors.initials: ML
authors.lastname: Lawrence
authors.forename: Gary
authors.initials: G
authors.lastname: Cunningham
authors.forename: Brian W
authors.initials: BW
authors.lastname: Christman
authors.forename: Barbara
authors.initials: B
authors.lastname: Meyrick
mesh_terms: D042683:Angiopoietin-1 / Q000494:pharmacology; D000818:Animals; D002196:Capillaries / Q000166:cytology / Q000502:physiology; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000166:cytology / Q000502:physiology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism*; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000502:physiology*; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013552:Swine; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D042683:Angiopoietin-1; D018841:HSP90 Heat-Shock Proteins; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt