CCN2 is transiently expressed by keratinocytes during re-epithelialization and regulates keratinocyte migration in vitro by the ras-MEK-ERK signaling pathway.
BACKGROUND
CCN2 (previously known as connective tissue growth factor) is a multifunctional matricellular protein that has numerous effects on cell life and cell interactions with the connective tissue. Although the importance of CCN2 for the fibrotic process in wound healing has been well studied, the involvement of CCN2 in keratinocyte function has not yet been explored. Therefore, the aim of the present study was to investigate the role of CCN2 in the epidermis during wound healing.


METHODS
Immunohistochemistry was done on sections from full-thickness porcine wounds. The effect of CCN2 on the migration of cultured human keratinocytes exposed to scratch wounds, the effect on phosphorylation of extracellular signal-related kinases (ERK), and the effect of adding inhibitors to the ERK/mitogen-activated protein kinase pathway to human keratinocytes were studied.


RESULTS
The CCN2 protein was transiently expressed in vivo at the leading keratinocyte edge during re-epithelialization of full-thickness porcine wounds. In vitro, exogenous addition of CCN2 to human keratinocyte cultures regulated keratinocyte migration and resulted in phosphorylation of ERK. The addition of inhibitors of ERK/mitogen-activated protein kinase counteracted the effect of CCN2 on migration.


CONCLUSIONS
CCN2 was transiently expressed at the leading keratinocyte edge in vivo. The biologic importance of this was supported in vitro, because CCN2 regulated human keratinocyte migration through activation of the Ras-mitogen-activated protein kinase kinase-ERK signal transduction pathway.
Division of Plastic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; Department of Surgical Sciences, Plastic Surgery Unit, Uppsala University, Uppsala, Sweden.
Elizabeth
E
Kiwanuka
Florian
F
Hackl
Edward J
EJ
Caterson
Daniel
D
Nowinski
Johan P E
JP
Junker
Bengt
B
Gerdin
Elof
E
Eriksson
D000818:Animals; D002465:Cell Movement / Q000502:physiology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D055513:Connective Tissue Growth Factor / Q000378:metabolism*; D000078404:Epidermal Cells; D004817:Epidermis / Q000293:injuries / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D066298:In Vitro Techniques; D015603:Keratinocytes / Q000378:metabolism*; D020935:MAP Kinase Signaling System / Q000502:physiology*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D034421:Sus scrofa; D014945:Wound Healing / Q000502:physiology*; D014947:Wounds and Injuries / Q000378:metabolism* / Q000473:pathology; D018631:ras Proteins / Q000378:metabolism
C526317:CCN2 protein, human; D055513:Connective Tissue Growth Factor; D020928:Mitogen-Activated Protein Kinases; D018631:ras Proteins
CCN2; Cell migration; Keratinocyte; Re-epithelialization; Wound healing