title: Leptin promotes wound healing in the oral mucosa.
abstract: BACKGROUND
  Leptin, a 16 kDa circulating anti-obesity hormone, exhibits many physiological properties. Recently, leptin was isolated from saliva; however, its function in the oral cavity is still unclear. In this study, we investigated the physiological role of leptin in the oral cavity by focusing on its effect on wound healing in the oral mucosa.
  
  
  METHODS
  Immunohistochemical analysis was used to examine the expression of the leptin receptor (Ob-R) in human/rabbit oral mucosa. To investigate the effect of leptin on wound healing in the oral mucosa, chemical wounds were created in rabbit oral mucosa, and leptin was topically administered to the wound. The process of wound repair was histologically observed and quantitatively analyzed by measuring the area of ulceration and the duration required for complete healing. The effect of leptin on the proliferation, differentiation and migration of human oral mucosal epithelial cells (RT7 cells) was investigated using crystal violet staining, reverse transcription polymerase chain reaction (RT-PCR) and a wound healing assay, respectively.
  
  
  RESULTS
  Ob-R was expressed in spinous/granular cells in the epithelial tissue and vascular endothelial cells in the subepithelial connective tissue of the oral mucosa. Topical administration of leptin significantly promoted wound healing and shortened the duration required for complete healing. Histological analysis of gingival tissue beneath the ulceration showed a denser distribution of blood vessels in the leptin-treated group. Although the proliferation and differentiation of RT7 cells were not affected by leptin, the migration of these cells was accelerated in the presence of leptin.
  
  
  CONCLUSIONS
  Topically administered leptin was shown to promote wound healing in the oral mucosa by accelerating epithelial cell migration and enhancing angiogenesis around the wounded area. These results strongly suggest that topical administration of leptin may be useful as a treatment to promote wound healing in the oral mucosa.
authors.affiliation: Department of Oral Medicine and Stomatology, Tsurumi University School of Dental Medicine, Yokohama, Kanagawa, Japan.
authors.forename: Hirochika
authors.initials: H
authors.lastname: Umeki
authors.affiliation: Department of Oral Medicine and Stomatology, Tsurumi University School of Dental Medicine, Yokohama, Kanagawa, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Tokuyama
authors.affiliation: Department of Oral Medicine and Stomatology, Tsurumi University School of Dental Medicine, Yokohama, Kanagawa, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Ide
authors.affiliation: Department of Oral Medicine and Stomatology, Tsurumi University School of Dental Medicine, Yokohama, Kanagawa, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Okubo
authors.affiliation: Department of Oral Medicine and Stomatology, Tsurumi University School of Dental Medicine, Yokohama, Kanagawa, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Tadokoro
authors.affiliation: Department of Oral Medicine and Stomatology, Tsurumi University School of Dental Medicine, Yokohama, Kanagawa, Japan.
authors.forename: Mitsuki
authors.initials: M
authors.lastname: Tezuka
authors.affiliation: Department of Oral Medicine and Stomatology, Tsurumi University School of Dental Medicine, Yokohama, Kanagawa, Japan.
authors.forename: Seiko
authors.initials: S
authors.lastname: Tatehara
authors.affiliation: Department of Oral Medicine and Stomatology, Tsurumi University School of Dental Medicine, Yokohama, Kanagawa, Japan.
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Satomura
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000818:Animals; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D042783:Endothelial Cells / Q000502:physiology; D004815:Epidermal Growth Factor / Q000096:biosynthesis; D004847:Epithelial Cells / Q000187:drug effects / Q000502:physiology*; D051523:Fibroblast Growth Factor 7 / Q000096:biosynthesis; D006801:Humans; D020738:Leptin / Q000627:therapeutic use*; D008297:Male; D009061:Mouth Mucosa / Q000502:physiology*; D011817:Rabbits; D054411:Receptors, Leptin / Q000096:biosynthesis; D014945:Wound Healing / Q000187:drug effects* / Q000502:physiology*
chemical_list: C496453:FGF7 protein, human; D020738:Leptin; D054411:Receptors, Leptin; D051523:Fibroblast Growth Factor 7; D004815:Epidermal Growth Factor