title: Wound healing improvement with PHD-2 silenced fibroblasts in diabetic mice.
abstract: BACKGROUND
  Hypoxia-inducible factor 1α is the central regulator of the hypoxia-induced response which results in the up-regulation of angiogenic factors. Its activity is under precise regulation of prolyl-hydroxylase domain 2. We hypothesized that PHD2 silenced fibroblasts would increase the expression of angiogenic factors, which might contribute to the improvement of the diabetic wound healing.
  
  
  METHODS
  50 dB/db mice were employed and randomly assigned into five groups with 10 mice in each: group 1 (untreated cell), group 2 (PHD2 silenced cell), group 3 (L-mimosine treated cells), group 4 (nontargeting siRNA treated cells) and group 5 (sham control). Fibroblasts were cultivated from the dermis of mice in each group and treated with PHD2 targeting siRNA, L-mimosine and non-targeting siRNA respectively. A fraction of the fibroblasts were employed to verify the silencing rate of PHD2 after 48 hours. The autologous fibroblasts (treated and untreated) labeled with adenovirus-GFP were implanted around the wound (Φ6mm), which was created on the dorsum of each mouse. The status of wounds was recorded periodically. Ten days postoperatively, 3 mice from each group were sacrificed and wound tissues were harvested. Molecular biological examinations were performed to evaluate the expressions of cytokines. 28 days postoperatively, the remaining mice were sacrificed. Histological examinations were performed to evaluate the densities of GFP+ cells and capillaries.
  
  
  RESULTS
  The expression of PHD2 reduced to 12.5%, and the expressions of HIF-1α and VEGFa increased significantly after PHD2 siRNA treatment. With the increasing expressions of HIF-1α and VEGFa, the time to wound closure in group 2 was less than 2 weeks. Increased numbers of GFP+ cells and capillaries were observed in group 2.
  
  
  CONCLUSIONS
  PHD2 siRNA treatment not only increased the expression of HIF1α and VEGFa, but also improved the fibroblast proliferation. These effects might contribute to the improvement of the diabetic wound healing.
authors.affiliation: Department of Orthopedics, Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Xiongliang
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Orthopedics, Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Yan
authors.affiliation: Department of Orthopedics, Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Cheng
authors.affiliation: Department of Orthopedics, Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Jiezhi
authors.initials: J
authors.lastname: Dai
authors.affiliation: Department of Orthopedics, Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Chunyang
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Orthopedics, Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Pei
authors.initials: P
authors.lastname: Han
authors.affiliation: Department of Orthopedics, Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Yimin
authors.initials: Y
authors.lastname: Chai
mesh_terms: D000818:Animals; D016207:Cytokines / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D020868:Gene Silencing / Q000187:drug effects; D049452:Green Fluorescent Proteins / Q000378:metabolism; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases / Q000172:deficiency*; D051379:Mice; D016688:Mice, Inbred NOD; D008898:Mimosine; D034741:RNA, Small Interfering / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D014945:Wound Healing / Q000502:physiology*
chemical_list: D016207:Cytokines; C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D034741:RNA, Small Interfering; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D049452:Green Fluorescent Proteins; D008898:Mimosine; C490189:Egln1 protein, mouse; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases