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BioMed Research International
Volume 2014, Article ID 401859, 9 pages
http://dx.doi.org/10.1155/2014/401859
Research Article

RhoA Controls Wnt Upregulation on Microstructured Titanium Surfaces

1Section of Periodontology and Implant Dentistry, Centro di Odontoiatria, University of Parma, Via Gramsci 14, 43126 Parma, Italy
2Department of Clinical and Experimental Medicine, University of Parma, Via Gramsci 14, 43126 Parma, Italy
3Department of Biomedical, Biotechnological, and Translational Sciences, University of Parma, Via Gramsci 14, 43126 Parma, Italy

Received 28 January 2014; Accepted 20 March 2014; Published 14 May 2014

Academic Editor: H. C. Van der Mei

Copyright © 2014 Simone Lumetti et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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.