title: Matrix- and plasma-derived peptides promote tissue-specific injury responses and wound healing in diabetic swine.
abstract: Non-healing wounds are a major global health concern and account for the majority of non-traumatic limb amputations worldwide. However, compared to standard care practices, few advanced therapeutics effectively resolve these injuries stemming from cardiovascular disease, aging, and diabetes-related vasculopathies. While matrix turnover is disrupted in these injuries, debriding enzymes may promote healing by releasing matrix fragments that induce cell migration, proliferation, and morphogenesis, and plasma products may also stimulate these processes. Thus, we created matrix- and plasma-derived peptides, Comb1 and UN3, which induce cellular injury responses in vitro, and accelerate healing in rodent models of non-healing wounds. However, the effects of these peptides in non-healing wounds in diabetes are not known. Here, we interrogated whether these peptides stimulate healing in a diabetic porcine model highly reminiscent of human healing impairments in type 1 and type 2-diabetes.
  
  
  
  After 3-6 weeks of streptozotocin-induced diabetes, full-thickness wounds were surgically created on the backs of adult female Yorkshire swine under general anesthesia. Comb1 and UN3 peptides or sterile saline (negative control) were administered to wounds daily for 3-7 days. Following sacrifice, wound tissues were harvested, and quantitative histological and immunohistochemical analyses were performed for wound closure, angiogenesis and granulation tissue deposition, along with quantitative molecular analyses of factors critical for angiogenesis, epithelialization, and dermal matrix remodeling.
  
  
  
  Comb1 and UN3 significantly increase re-epithelialization and angiogenesis in diabetic porcine wounds, compared to saline-treated controls. Additionally, fluorescein-conjugated Comb1 labels keratinocytes, fibroblasts, and vascular endothelial cells in porcine wounds, and Far western blotting reveals these cell populations express multiple fluorescein-Comb1-interacting proteins in vitro. Further, peptide treatment increases mRNA expression of several pro-angiogenic, epithelializing, and matrix-remodeling factors, importantly including balanced inductions in matrix metalloproteinase-2, -9, and tissue inhibitor of metalloproteinases-1, lending further insight into their mechanisms.
  
  
  
  Comb1 and UN3 stimulate wound resolution in diabetic Yorkshire swine through upregulation of multiple reparative growth factors and cytokines, especially matrix metalloproteinases and inhibitors that may aid in reversing the proteolytic imbalance characteristic of chronically inflamed non-healing wounds. Together, these peptides should have great therapeutic potential for all patients in need of healing, regardless of injury etiology.
authors.affiliation: Graduate Program in Cellular & Molecular Physiology, The Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA, 02111, USA.|Department of Developmental, Molecular and Chemical Biology, School of Medicine, Tufts University, 136 Harrison Ave, Boston, MA, 02111, USA.|The Center for Innovations in Wound Healing Research, School of Medicine, Tufts University, 136 Harrison Ave, Boston, MA, 02111, USA.
authors.forename: Anthony R
authors.initials: AR
authors.lastname: Sheets
authors.affiliation: The Center for Innovations in Wound Healing Research, School of Medicine, Tufts University, 136 Harrison Ave, Boston, MA, 02111, USA.
authors.forename: Conner J
authors.initials: CJ
authors.lastname: Massey
authors.affiliation: The Center for Innovations in Wound Healing Research, School of Medicine, Tufts University, 136 Harrison Ave, Boston, MA, 02111, USA.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Cronk
authors.affiliation: The Center for Innovations in Wound Healing Research, School of Medicine, Tufts University, 136 Harrison Ave, Boston, MA, 02111, USA.|Department of Surgery, Division of Vascular Surgery, Tufts Medical Center, 800 Washington St., Boston, MA, 02111, USA.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Iafrati
authors.affiliation: Graduate Program in Cellular & Molecular Physiology, The Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA, 02111, USA. ira.herman@tufts.edu.|Graduate Program in Cell, Molecular and Developmental Biology, The Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA, 02111, USA. ira.herman@tufts.edu.|Department of Developmental, Molecular and Chemical Biology, School of Medicine, Tufts University, 136 Harrison Ave, Boston, MA, 02111, USA. ira.herman@tufts.edu.|The Center for Innovations in Wound Healing Research, School of Medicine, Tufts University, 136 Harrison Ave, Boston, MA, 02111, USA. ira.herman@tufts.edu.
authors.forename: Ira M
authors.initials: IM
authors.lastname: Herman
mesh_terms: D000328:Adult; D043925:Angiogenesis Inducing Agents / Q000378:metabolism; D000818:Animals; D054377:Chemokine CXCL12 / Q000235:genetics / Q000378:metabolism; D002633:Chemotaxis / Q000187:drug effects; D003921:Diabetes Mellitus, Experimental / Q000473:pathology*; D004815:Epidermal Growth Factor / Q000378:metabolism; D005109:Extracellular Matrix / Q000737:chemistry*; D005260:Female; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000187:drug effects; D009928:Organ Specificity / Q000187:drug effects*; D010455:Peptides / Q000097:blood* / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D019718:Receptors, CXCR4 / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D034421:Sus scrofa; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D043925:Angiogenesis Inducing Agents; D054377:Chemokine CXCL12; D010455:Peptides; D012333:RNA, Messenger; D019718:Receptors, CXCR4; D004815:Epidermal Growth Factor; D016650:Fluorescein-5-isothiocyanate
keywords: Angiogenesis; Chronic wound care; Diabetic foot ulcer; Molecular medicine; Re-epithelialization