The Effect of Thymosin β4 for Osteoblast Adhesion on Titanium Surface

Titanium (Ti) is the most widely used implant material in dentistry and orthopedics but the release of metal ions from Ti implants results in increased bone resorption by enhancing the production of inflammatory cytokines from the macrophages and facilitating osteoclast differentiation. Thymosin β4 (Tβ4) has several biological activities, such as promoting wound healing, angiogenesis, cell proliferation and migration in mammalian cells. This study examined the role of Tβ4 in osteoblasts via focal adhesions (FAs) and ERK1/2 signaling related to cell adhesion and proliferation for cell survival on the Ti surface. As a result, cell adhesion and proliferation increased in the Tβ4 treated cells (Tβ4/MC3T3-E1) but was significantly lower in the Tβ4 knock-down cells by Tβ4-siRNA (si-Tβ4/MC3T3-E1) than that of the untreated cells. The levels of FAK phosphorylation, paxillin expression, and paxillin localization were higher in the Tβ4/IMC3T3-E1 cells than that of the untreated cells but lower in the si-Tβ4/MC3T3-E1 cells. In addition, the levels of cell proliferation, Grb2 and Ras protein expression and phosphorylation of ERK1/2 were higher in the Tβ4/MC3T3-E1 cells than in the untreated cells but lower in the si-Tβ4/IMC3T3-E1 cells. These results suggest that Tβ4 might be a good nanomolecule that promotes osteoblast survival by facilitating adhesion and proliferation on the Ti surface.