title: A novel autologous cell-based therapy to promote diabetic wound healing.
abstract: OBJECTIVE
  We have previously shown that stromal cell-derived factor-1α (SDF-1α) is downregulated within diabetic cutaneous wounds, and that direct application of recombinant SDF-1α increases wound closure rates, neovascularization, and endothelial progenitor cell (EPC) recruitment. However, increased wound levels of exogenous SDF-1α results in elevated systemic levels of this proangiogenic chemokine that raises concerns for tumorigenesis and inflammation. We now seek to test the efficacy of a novel, safer cell-based therapy (CBT) employing ex vivo primed bone marrow-derived stem cells (BMDSC) with SDF-1α. We also elucidate the mechanism of action of this new approach for accelerating diabetic wound healing.
  
  
  METHODS
  Unfractionated BMDSC from diabetic Lepr mice were incubated for 20 hours with SDF-1α (100 ng/mL) or bovine serum albumin (control). Pretreated BMDSC (1 × 10) were injected subcutaneously into full-thickness skin wounds in Lepr mice (n = 8 per group). Wound closure rates, capillary density, and the recruitment of EPC were assessed with serial photography, DiI perfusion, confocal microscopy, and immunohistochemistry. The expression of molecular targets, which may mediate prohealing/proangiogenic effects of SDF-1α-primed BMDSC was evaluated by polymerase chain reaction array and immunoblotting assay. The biological function of a potential mediator was tested in a mouse wound-healing model. Serum SDF-1α levels were measured with enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  SDF-1α-primed BMDSC significantly promote wound healing (P < 0.0001), neovascularization (P = 0.0028), and EPC recruitment (P = 0.0059). Gene/protein expression studies demonstrate upregulation of Ephrin Receptor B4 and plasminogen as downstream targets potentially mediating the prohealing and proangiogenic responses. Ex vivo BMDSC activation and the subsequent inoculation of cells into wounds does not increase systemic SDF-1α levels.
  
  
  CONCLUSIONS
  We report a novel CBT that is highly effective in promoting healing and neovascularization in a murine model of type 2 diabetes. Furthermore, we identify new molecular targets that may be important for advancing the field of wound healing.
authors.affiliation: Department of Surgery, Miller School of Medicine, University of Miami, FL, USA.
authors.forename: Diego M
authors.initials: DM
authors.lastname: Castilla
authors.forename: Zhao-Jun
authors.initials: ZJ
authors.lastname: Liu
authors.forename: Runxia
authors.initials: R
authors.lastname: Tian
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Alan S
authors.initials: AS
authors.lastname: Livingstone
authors.forename: Omaida C
authors.initials: OC
authors.lastname: Velazquez
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D016026:Bone Marrow Transplantation / Q000379:methods*; D054377:Chemokine CXCL12 / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications*; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D015151:Immunoblotting; D008297:Male; D051379:Mice; D018613:Microscopy, Confocal; D018919:Neovascularization, Physiologic; D010958:Plasminogen / Q000378:metabolism; D016133:Polymerase Chain Reaction; D062326:Re-Epithelialization; D012867:Skin / Q000098:blood supply / Q000293:injuries*; D012879:Skin Physiological Phenomena; D017695:Soft Tissue Injuries / Q000628:therapy; D033581:Stem Cell Transplantation / Q000379:methods*; D016896:Treatment Outcome; D014945:Wound Healing / Q000502:physiology
chemical_list: D015415:Biomarkers; D054377:Chemokine CXCL12; D010958:Plasminogen