title: Bone marrow cells differentiate into wound myofibroblasts and accelerate the healing of wounds with exposed bones when combined with an occlusive dressing.
abstract: BACKGROUND
  The usefulness of bone marrow cells in accelerating wound healing has not been evaluated despite increasing evidence that bone marrow contains mesenchymal stem cells that have multipotentiality to differentiate into various types of cells after they enter the microenvironment of a specific tissue (niche).
  
  
  OBJECTIVE
  To determine the effects of bone marrow cells and occlusive dressings in promoting wound healing in rats.
  
  
  METHODS
  We investigated by grafting, biopsy and immunohistochemistry whether various types of cells derived from green fluorescent protein (GFP)-transgenic rats would differentiate into wound component cells when administered topically on the wounds of rats. We also investigated whether topical application of bone marrow cells with an occlusive dressing would accelerate the healing of wounds with exposed bones, as measured by planimetry.
  
  
  RESULTS
  GFP-labelled bone marrow cells contained multipotent stem cells that sufficiently differentiated into wound myofibroblasts presenting with alpha-smooth muscle actin in granulation tissue. Other types of cells, including myocytes, adipocytes, peripheral blood cells from buffy coat and dermal fibroblasts, did not express myofibroblast characteristics morphologically or immunohistochemically. Application of bone marrow cells and an occlusive dressing accelerated the repair of wounds with exposed bones, compared with an occlusive dressing only or with the topical administration of bone marrow cells plus a semidry to dry dressing.
  
  
  CONCLUSIONS
  Our study indicates that bone marrow cells accelerate the healing of wounds at least in part through their differentiation into wound myofibroblasts. Thus, treatment of wounds with bone marrow cells and a supportive occlusive dressing is effective in promoting the formation of healthy granulation tissue and also for the preparation of an ideal wound bed.
authors.affiliation: Department of Dermatology, Graduate School of Medicine, Osaka University, 2-2 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: T
authors.initials: T
authors.lastname: Kubo
authors.forename: T
authors.initials: T
authors.lastname: Murakami
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.forename: Y
authors.initials: Y
authors.lastname: Hakamata
authors.forename: E
authors.initials: E
authors.lastname: Kobayashi
authors.forename: S
authors.initials: S
authors.lastname: Yoshida
authors.forename: K
authors.initials: K
authors.lastname: Hosokawa
authors.forename: K
authors.initials: K
authors.lastname: Yoshikawa
authors.forename: S
authors.initials: S
authors.lastname: Itami
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001854:Bone Marrow Cells / Q000502:physiology*; D016026:Bone Marrow Transplantation / Q000379:methods; D002454:Cell Differentiation / Q000502:physiology; D017690:Cell Transplantation / Q000379:methods; D005347:Fibroblasts / Q000502:physiology; D007150:Immunohistochemistry / Q000379:methods; D009130:Muscle, Smooth / Q000293:injuries / Q000473:pathology; D009779:Occlusive Dressings; D051381:Rats; D017208:Rats, Wistar; D014945:Wound Healing / Q000502:physiology*