title: Topical prolyl hydroxylase domain-2 silencing improves diabetic murine wound closure.
abstract: Prolyl hydroxylase domain 2 (PHD2) has been implicated in several pathways of cell signaling, most notably in its regulation of hypoxia-inducible factor (HIF)-1α stability. In normoxia, PHD2 hydroxylates proline residues on HIF-1α, rendering it inactive. However, in hypoxia, PHD2 is inactive, HIF-1α is stabilized and downstream effectors such as vascular endothelial growth factor and fibroblast growth factor-2 are produced to promote angiogenesis. In the present study we utilize RNA interference to PHD2 to promote therapeutic angiogenesis in a diabetic wound model, presumably by the stabilization of HIF-1α. Stented wounds were created on the dorsum of diabetic Lepr db/db mice. Mice were treated with PHD2 small interfering RNA (siRNA) or nonsense siRNA. Wounds were measured photometrically on days 0-28. Wounds were harvested for histology, protein, and RNA analysis. Diabetic wounds treated with siRNA closed within 21±1.2 days; sham-treated closed in 28±1.5 days. By day 7, Western blot revealed near complete suppression of PHD protein and corresponding increased HIF-1α. Angiogenic mediators vascular endothelial growth factor and fibroblast growth factor-2 were elevated, corresponding to increased CD31 staining in the treated groups. siRNA-mediated silencing of PHD2 increases HIF-1α and several mediators of angiogenesis. This corresponded to improved time to closure in diabetic wounds compared with sham-treated wounds. These findings suggest that impaired wound healing in diabetes can be ameliorated with therapeutic angiogenesis.
authors.affiliation: Institute of Reconstructive Plastic Surgery, New York University Langone Medical Center, USA.
authors.forename: Meredith
authors.initials: M
authors.lastname: Wetterau
authors.forename: Finny
authors.initials: F
authors.lastname: George
authors.forename: Andrew
authors.initials: A
authors.lastname: Weinstein
authors.forename: Phuong D
authors.initials: PD
authors.lastname: Nguyen
authors.forename: John Paul
authors.initials: JP
authors.lastname: Tutela
authors.forename: Denis
authors.initials: D
authors.lastname: Knobel
authors.forename: Oriana
authors.initials: O
authors.lastname: Cohen Ba
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Warren
authors.forename: Pierre B
authors.initials: PB
authors.lastname: Saadeh
mesh_terms: D000818:Animals; D003920:Diabetes Mellitus / Q000378:metabolism; D004195:Disease Models, Animal; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000378:metabolism; D020868:Gene Silencing; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism*; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases; D051379:Mice; D018919:Neovascularization, Physiologic; D011393:Procollagen-Proline Dioxygenase / Q000037:antagonists & inhibitors* / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering; D012867:Skin / Q000293:injuries / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism; D014945:Wound Healing
chemical_list: C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D042461:Vascular Endothelial Growth Factor A; D016222:Fibroblast Growth Factor 2; D011393:Procollagen-Proline Dioxygenase; C490189:Egln1 protein, mouse; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases