title: RhoA controls Wnt upregulation on microstructured titanium surfaces.
abstract: Rough topography enhances the activation of Wnt canonical signaling in vitro, and this mediates its effects on cell differentiation. However, the molecular mechanisms underlying topography-dependent control of Wnt signaling are still poorly understood. As the small GTPase RhoA controls cytoskeletal reorganization and actomyosin-induced tensional forces, we hypothesized that RhoA could affect the activation of Wnt signaling in cells on micropatterned titanium surfaces. G-LISA assay revealed that RhoA activation was higher in C2C12 cells on rough (SLA) surfaces under basal conditions than on smooth (Polished) titanium. Transfection with dominant negative RhoA decreased Wnt activation by normalized TCF-Luc activity on SLA, whilst transfection with constitutively active RhoA increased TCF-Luc activation on Polished titanium. One mM Myosin II inhibitor Blebbistatin increased RhoA activation but decreased Wnt activation on SLA surfaces, indicating that tension-generating structures are required for canonical Wnt modulation on titanium surfaces. Actin inhibitor Cytochalasin markedly enhanced RhoA and TCF-Luc activation on both surfaces and increased the expression of differentiation markers in murine osteoblastic MC3T3 cells. Taken together, these data show that RhoA is upregulated in cells on rough surfaces and it affects the activation of Wnt canonical signaling through Myosin II modulation.
authors.affiliation: Section of Periodontology and Implant Dentistry, Centro di Odontoiatria, University of Parma, Via Gramsci 14, 43126 Parma, Italy.
authors.forename: Simone
authors.identifier: 0000-0002-0826-927X
authors.initials: S
authors.lastname: Lumetti
authors.affiliation: Department of Clinical and Experimental Medicine, University of Parma, Via Gramsci 14, 43126 Parma, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Mazzotta
authors.affiliation: Department of Clinical and Experimental Medicine, University of Parma, Via Gramsci 14, 43126 Parma, Italy.
authors.forename: Sara
authors.identifier: 0000-0002-0436-2506
authors.initials: S
authors.lastname: Ferrillo
authors.affiliation: Section of Periodontology and Implant Dentistry, Centro di Odontoiatria, University of Parma, Via Gramsci 14, 43126 Parma, Italy.
authors.forename: Maddalena
authors.initials: M
authors.lastname: Piergianni
authors.affiliation: Section of Periodontology and Implant Dentistry, Centro di Odontoiatria, University of Parma, Via Gramsci 14, 43126 Parma, Italy.
authors.forename: Marilina
authors.initials: M
authors.lastname: Piemontese
authors.affiliation: Department of Clinical and Experimental Medicine, University of Parma, Via Gramsci 14, 43126 Parma, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Passeri
authors.affiliation: Section of Periodontology and Implant Dentistry, Centro di Odontoiatria, University of Parma, Via Gramsci 14, 43126 Parma, Italy ; Department of Biomedical, Biotechnological, and Translational Sciences, University of Parma, Via Gramsci 14, 43126 Parma, Italy.
authors.forename: Guido Maria
authors.identifier: 0000-0003-2203-3092
authors.initials: GM
authors.lastname: Macaluso
authors.affiliation: Section of Periodontology and Implant Dentistry, Centro di Odontoiatria, University of Parma, Via Gramsci 14, 43126 Parma, Italy.
authors.forename: Carlo
authors.identifier: 0000-0001-7476-7181
authors.initials: C
authors.lastname: Galli
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation / Q000235:genetics*; D002460:Cell Line; D003572:Cytochalasins / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D024462:Myosin Type II / Q000378:metabolism; D010012:Osteogenesis; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D060449:Wnt Signaling Pathway / Q000187:drug effects / Q000235:genetics*; D020741:rho GTP-Binding Proteins / Q000096:biosynthesis*; D020742:rhoA GTP-Binding Protein
chemical_list: D003572:Cytochalasins; C031218:cytochalasin A; D014025:Titanium; D024462:Myosin Type II; C526380:RhoA protein, mouse; D020741:rho GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein