CCN2 – Keratinocyte Interactions In Vitro and In Vivo
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Cutaneous wound healing is a complex process involving the migration of inflammatory cells to the wound site, deposition of extracellular matrix, and the reestablishment of an intact epithelial barrier. Re-epithelialization depends on the proliferation and directional migration of keratinocytes from the wound edges. Initially, keratinocytes migrate over a provisional wound matrix that is rich in fibronectin, and as the wound heals the provisional matrix becomes replaced by one consisting of collagen and proteoglycans. Re-epithelialization is tightly regulated by a variety of peptides such as growth factors, cytokines and proteases, and abnormalities may result in chronic non-healing wounds or hypertrophic scars. CCN2 (Connective Tissue Growth Factor) is a multifunctional protein with effects on cells and their interactions with the connective tissue. CCN2 is expressed in a variety of cell types and regulates numerous cell functions including proliferation, differentiation, adhesion, migration and stimulation of collagen production. While the importance of CCN2 for the fibrotic response has been well studied, its involvement in keratinocyte function has not yet been fully explored. Using an in vivo wound model, the expression of CCN2 was captured at the leading keratinocyte edge during re-epithelialization. In vitro, exogenous addition of CCN2 to human keratinocyte cultures promoted keratinocyte migration. Subsequently, integrin a5b1 was identified as an important mediator of CCN2 enhancement of keratinocyte adhesion to fibronectin. CCN2 activated the FAK-MAPK signaling pathway, and pretreatment with MEK1 specific inhibitor PD98059 markedly reduced CCN2-promoted keratinocyte migration. In vitro, CCN2 expression was induced by TGF-β1. Compared with inhibiting the SMAD pathway, blocking MAPK was more effective in reducing TGF-β1-induced CCN2 mRNA and protein expression. In addition, CCN2-induced keratinocyte spreading required FAK. Treatment with CCN2 led to actin disassembly and altered the activity of the Rho proteins and p190RhoGAP in keratinocytes. Furthermore, Cdc42 mediated CCN2-induced cell polarity. In conclusion, using in vivo and in vitro models, CCN2 was shown to regulate keratinocyte function by promoting keratinocyte adhesion, spreading and migration. A complete understanding of CCN2 expression in keratinocytes is crucial in order to develop novel therapies for wound healing.
Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2014. , 61 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, ISSN 1651-6206 ; 968
CCN2, connective tissue growth factor, keratinocytes, re-epithelialization, cell migration, cell signaling
Medical and Health Sciences
Research subject Plastic Surgery
IdentifiersURN: urn:nbn:se:uu:diva-213566ISBN: 978-91-554-8853-6OAI: oai:DiVA.org:uu-213566DiVA: diva2:685086
2014-02-28, Skoogsalen, Akademiska sjukhuset; Ingång 78-79, Uppsala, 13:15 (English)
Farnebo, Filip, Adj. professor
Gerdin, Bengt, ProfessorRubin, Kristofer, Professor
List of papers