TY - JOUR
T1 - RhoA controls Wnt upregulation on microstructured titanium surfaces
AU - Lumetti, Simone
AU - Mazzotta, Silvia
AU - Ferrillo, Sara
AU - Piergianni, Maddalena
AU - Piemontese, Marilina
AU - Passeri, Giovanni
AU - Macaluso, Guido Maria
AU - Galli, Carlo
N1 - Acknowledgments
The authors would like to thank Straumann Institut AG (and in particular Dr. Appert and Dr. Molenberg), Basel, Switzerland, for kindly providing the titanium surfaces used in the present study. The authors are also grateful to Dr. Francesca Ravanetti and Professor Antonio Cacchioli for their precious advices and technical assistance. The authors would like to thank Dr. Klaus Hahn for sharing his RhoA isoforms through the Addgene plasmid public repository. The study was funded by Grant no. 839_2012 from the ITI Foundation (Basel, Switzerland).
PY - 2014/5/14
Y1 - 2014/5/14
N2 - 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.
AB - 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.
U2 - 10.1155/2014/401859
DO - 10.1155/2014/401859
M3 - Article
VL - 2014
JO - BioMed Research International
JF - BioMed Research International
SN - 2314-6133
M1 - 401859
ER -