title: Regulation of matrix remodelling phenotype in gingival fibroblasts by substratum topography.
abstract: Gingival connective tissue often has a composition resembling that of scar surrounding dental implant abutments. Increased cell adhesion, α-smooth muscle actin (α-SMA) expression and increased extracellular matrix deposition are a hallmark of fibrotic cells, but how topographic features influence gingival fibroblast adhesion and adoption of the α-SMA positive myofibroblast phenotype associated with scarring is unknown. The purpose of the present study was to demonstrate whether implant topographies that limit adhesion formation would reduce myofibroblast differentiation and extracellular matrix deposition. Human gingival fibroblasts were cultured on PT (smooth) and SLA (roughened) titanium discs for varying time-points. At 1 and 2 weeks after seeding, incorporation of α-SMA into stress-fibre bundles and fibronectin deposition was significantly higher on PT than SLA surfaces indicating differentiation of the cells towards a myofibroblast phenotype. Analysis of adhesion formation demonstrated that cells formed larger adhesions and more stable adhesions on PT, with more nascent adhesions observed on SLA. Gene expression analysis identified up-regulation of 15 genes at 24 hrs on SLA versus PT associated with matrix remodelling. Pharmacological inhibition of Src/FAK signalling in gingival fibroblasts on PT reduced fibronectin deposition and CCN2 expression. We conclude that topographical features that reduce focal adhesion stability could be applied to inhibit myofibroblast differentiation in gingival fibroblasts.
authors.affiliation: Department of Anatomy & Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada.
authors.forename: Shawna S
authors.initials: SS
authors.lastname: Kim
authors.affiliation: Division of Oral Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada.
authors.forename: Weiyan
authors.initials: W
authors.lastname: Wen
authors.affiliation: Graduate Program of Biomedical Engineering, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Prowse
authors.affiliation: Department of Anatomy & Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada.|Division of Oral Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada.|Graduate Program of Biomedical Engineering, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada.
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Hamilton
mesh_terms: D000199:Actins / Q000378:metabolism; D015153:Blotting, Western; D002448:Cell Adhesion; D002454:Cell Differentiation; D002478:Cells, Cultured; D055513:Connective Tissue Growth Factor / Q000235:genetics; D005109:Extracellular Matrix / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism; D022001:Focal Adhesions / Q000378:metabolism; D015870:Gene Expression; D005881:Gingiva / Q000166:cytology*; D006801:Humans; D007150:Immunohistochemistry; D008855:Microscopy, Electron, Scanning; D058628:Myofibroblasts / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D022502:Stress Fibers / Q000378:metabolism; D013499:Surface Properties; D019699:Thrombospondins / Q000235:genetics; D014025:Titanium / Q000737:chemistry / Q000378:metabolism; D000099262:Thrombospondin 2
chemical_list: D000199:Actins; D055513:Connective Tissue Growth Factor; D005353:Fibronectins; D019699:Thrombospondins; D014025:Titanium; D000099262:Thrombospondin 2; C541116:ACTA2 protein, human; C526317:CCN2 protein, human
keywords: adhesion formation; dental implant; gingival fibroblasts; integrins; substratum topography; titanium