title: Silencing of int6 gene restores function of the ischaemic hindlimb in a rat model of peripheral arterial disease.
abstract: OBJECTIVE
  Intermittent claudication (IC) is one of the serious symptoms of peripheral arterial disease (PAD) and is characterized by pain in the legs or buttocks that worsens with exercise and subsides with rest. The concept of 'therapeutic angiogenesis' for PAD has been widely proposed; however, the methodology, including cell transplantation, is still unclear. In this study, we examined the clinical efficacy of silencing the int6 gene, which encodes a protein that stabilizes hypoxia-inducible factor (HIF)-2α, on angiogenesis in PAD.
  
  
  RESULTS
  An animal model for IC was established in Sprague-Dawley rats by external iliac artery ligation and evaluated by quantitative analysis of gait disturbance. Next, we explored the therapeutic effects of int6 siRNA injected into the adductor magnus muscle on IC. Recovery of hindlimb function occurred in the early stages after int6 siRNA injection. The number of blood vessels showed an obvious increase in the int6 siRNA-treated muscles. Angiography revealed the recovery of peripheral circulation at the affected sites. Early up-regulation of HIF-2α and other angiogenic factors, including basic fibroblast growth factor and hepatocyte growth factor, was also apparent in the int6 siRNA-treated sites. We also confirmed the up-regulation of HIF-2α and its translocation to the nucleus in the int6 siRNA-injected muscle.
  
  
  CONCLUSIONS
  A single injection of int6 siRNA promoted angiogenesis via up-regulation of HIF-2α-related angiogenic factors in the muscles of the affected hindlimb and reduced gait disturbance. The int6 gene may be a novel therapeutic target for the treatment of IC in patients with PAD.
authors.affiliation: Laboratory of Veterinary Molecular Pathology and Therapeutics, Division of Animal Life Science,  Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Okamoto
authors.forename: Akane
authors.initials: A
authors.lastname: Tanaka
authors.forename: Kyungsook
authors.initials: K
authors.lastname: Jung
authors.forename: Kaoru
authors.initials: K
authors.lastname: Karasawa
authors.forename: Kensuke
authors.initials: K
authors.lastname: Orito
authors.forename: Akira
authors.initials: A
authors.lastname: Matsuda
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Amagai
authors.forename: Kumiko
authors.initials: K
authors.lastname: Oida
authors.forename: Keitaro
authors.initials: K
authors.lastname: Ohmori
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsuda
mesh_terms: D042501:Angiogenic Proteins / Q000378:metabolism; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D001783:Blood Flow Velocity; D004195:Disease Models, Animal; D039621:Eukaryotic Initiation Factor-3 / Q000235:genetics*; D005684:Gait; D020868:Gene Silencing; D015316:Genetic Therapy / Q000379:methods*; D006614:Hindlimb; D007273:Injections, Intramuscular; D007511:Ischemia / Q000209:etiology / Q000235:genetics / Q000503:physiopathology / Q000628:therapy*; D017078:Laser-Doppler Flowmetry; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000503:physiopathology; D018919:Neovascularization, Physiologic; D058729:Peripheral Arterial Disease / Q000150:complications / Q000235:genetics / Q000503:physiopathology / Q000628:therapy*; D034741:RNA, Small Interfering / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function; D012039:Regional Blood Flow; D013997:Time Factors; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D042501:Angiogenic Proteins; D051792:Basic Helix-Loop-Helix Proteins; D039621:Eukaryotic Initiation Factor-3; D034741:RNA, Small Interfering; D000099162:Endothelial PAS Domain-Containing Protein 1