title: Enhancement of ischemia-induced angiogenesis by eNOS overexpression.
abstract: It remains undetermined whether continuous endothelial nitric oxide (NO) overexpression exerts angiogenic action. We surgically induced hindlimb ischemia in transgenic mice overexpressing endothelial NO synthase in the endothelium (eNOS-Tg) and studied neocapillary formation, ischemia-induced vascular endothelial growth factor (VEGF) expression, cGMP accumulation, and Akt/PKB signaling. Laser Doppler imaging revealed a markedly increased recovery of blood perfusion in ischemic limbs of eNOS-Tg mice (44% increase) compared with that in wild-type mice. Angiography showed a marked increase in basal and ischemia-induced collateral vessel formation in eNOS-Tg mice. Basal capillary densities and tissue cGMP levels were increased in eNOS-Tg mice (1.8-fold and 1.6-fold versus wild-type mice, respectively). Ischemia-induced neocapillary formation and cGMP accumulation were markedly increased in eNOS-Tg mice (3.6-fold and 4.1-fold versus preischemia levels, respectively), whereas those in wild-type mice were much less (1.8-fold and 1.5-fold, respectively). Basal and time-dependent VEGF expression in ischemic muscles did not differ between eNOS-Tg and wild-type mice. Basal and VEGF-mediated Akt phosphorylation in aortas was similar between eNOS-Tg and wild-type mice. Aortic basal eNOS expression was increased 3.3-fold, and VEGF-mediated eNOS phosphorylation was markedly induced in aortas of eNOS-Tg compared with preischemia levels (4.2-fold), whereas much smaller changes were observed in wild-type mice (1.8-fold increase). Our study demonstrates that overexpression of eNOS protein causes a marked increase in neocapillary formation in response to tissue ischemia without affecting ischemia-induced VEGF expression or VEGF-mediated Akt phosphorylation.
authors.affiliation: Department of Medicine II and Cardiovascular Center, Kansai Medical University, Moriguchi, Osaka, Japan.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Amano
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Matsubara
authors.forename: Osamu
authors.initials: O
authors.lastname: Iba
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Okigaki
authors.forename: Soichiro
authors.initials: S
authors.lastname: Fujiyama
authors.forename: Takanobu
authors.initials: T
authors.lastname: Imada
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kojima
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Nozawa
authors.forename: Seinosuke
authors.initials: S
authors.lastname: Kawashima
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Yokoyama
authors.forename: Toshiji
authors.initials: T
authors.lastname: Iwasaka
mesh_terms: D000792:Angiography; D000818:Animals; D001775:Blood Circulation; D002196:Capillaries / Q000254:growth & development; D003097:Collateral Circulation; D006152:Cyclic GMP / Q000032:analysis; D016228:Endothelial Growth Factors / Q000235:genetics / Q000494:pharmacology; D006614:Hindlimb / Q000098:blood supply; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000494:pharmacology; D007511:Ischemia / Q000097:blood* / Q000201:enzymology / Q000378:metabolism; D017078:Laser-Doppler Flowmetry; D008222:Lymphokines / Q000235:genetics / Q000494:pharmacology; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D018919:Neovascularization, Physiologic; D019001:Nitric Oxide Synthase / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D012333:RNA, Messenger / Q000096:biosynthesis; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
chemical_list: D016228:Endothelial Growth Factors; D036341:Intercellular Signaling Peptides and Proteins; D008222:Lymphokines; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496315:Nos3 protein, mouse; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D006152:Cyclic GMP