title: A phosphodiesterase-5 inhibitor vardenafil enhances angiogenesis through a protein kinase G-dependent hypoxia-inducible factor-1/vascular endothelial growth factor pathway.
abstract: OBJECTIVE
  We examined whether phosphodiesterase-5 (PDE5) inhibition can promote ischemia-induced angiogenesis.
  
  
  RESULTS
  Unilateral hindlimb ischemia was generated by resecting right femoral artery in wild-type C3H/He mice, treated with either vehicle or a PDE5 inhibitor vardenafil (10 mg/kg per day). Four weeks after surgery, vardenafil significantly enhanced blood flow recovery and augmented capillary collateral formation in ischemic muscle (blood flow ratios of ischemic/nonischemic leg: 0.52+/-0.17 [vehicle] versus 0.92+/-0.09 [vardenafil], P<0.01). Vardenafil upregulated protein expression of vascular endothelial growth factor and hypoxia-inducible factor (HIF)-1 alpha in ischemic muscle and enhanced mobilization of Sca-1/Flk-1-positive endothelial progenitor cells (EPCs) in peripheral blood and bone marrow, contributing to neovascularization. Vardenafil also promoted capillary-like tube formation of human umbilical vein endothelial cells and increased the number of human blood mononuclear cell-derived EPCs in vitro. Furthermore, reporter assays showed that vardenafil and cGMP activated the transactivation activity of HIF-1 under hypoxia. These effects of vardenafil were markedly inhibited by genetic ablation of endothelial nitric oxide synthase, a soluble guanylate cyclase inhibitor, and a protein kinase G inhibitor, respectively.
  
  
  CONCLUSIONS
  Our results suggest that PDE5 inhibition enhances ischemia-induced angiogenesis with mobilization of EPCs through a protein kinase G-dependent HIF-1/vascular endothelial growth factor pathway. PDE5 inhibition may have a therapeutic potential to treat ischemic cardiovascular diseases.
authors.affiliation: Department of Cardiovascular Medicine, University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan. tky@umin.ac.jp
authors.forename: Makoto
authors.initials: M
authors.lastname: Sahara
authors.forename: Masataka
authors.initials: M
authors.lastname: Sata
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Morita
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Nakajima
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Hirata
authors.forename: Ryozo
authors.initials: R
authors.lastname: Nagai
mesh_terms: D043925:Angiogenesis Inducing Agents / Q000494:pharmacology*; D000818:Animals; D002196:Capillaries / Q000187:drug effects / Q000201:enzymology / Q000503:physiopathology; D015687:Cell Hypoxia; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D003097:Collateral Circulation / Q000187:drug effects; D006152:Cyclic GMP / Q000378:metabolism; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism*; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5 / Q000378:metabolism; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D006614:Hindlimb; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism*; D007093:Imidazoles / Q000494:pharmacology*; D007511:Ischemia / Q000188:drug therapy* / Q000201:enzymology / Q000503:physiopathology; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D018482:Muscle, Skeletal / Q000098:blood supply*; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D052250:Nitric Oxide Synthase Type III / Q000172:deficiency / Q000235:genetics; D058986:Phosphodiesterase 5 Inhibitors; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D010879:Piperazines / Q000494:pharmacology*; D034622:RNA Interference; D020127:Recovery of Function; D012039:Regional Blood Flow / Q000187:drug effects; D015398:Signal Transduction; D013234:Stem Cells / Q000187:drug effects / Q000378:metabolism; D013450:Sulfones / Q000494:pharmacology; D013997:Time Factors; D014162:Transfection; D014227:Triazines / Q000494:pharmacology; D000069058:Vardenafil Dihydrochloride; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*
chemical_list: D043925:Angiogenesis Inducing Agents; C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007093:Imidazoles; D058986:Phosphodiesterase 5 Inhibitors; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D013450:Sulfones; D014227:Triazines; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D049452:Green Fluorescent Proteins; D000069058:Vardenafil Dihydrochloride; D052250:Nitric Oxide Synthase Type III; C496315:Nos3 protein, mouse; D017869:Cyclic GMP-Dependent Protein Kinases; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; C517382:Pde5a protein, mouse; D006152:Cyclic GMP