Wnt3a is a secreted glycoprotein that activates the glycogen synthase kinase-3 beta (GSK3 beta)/beta-catenin signaling pathway through low-density-lipoprotein receptor-related protein (LRP)5/6 co-receptors. Wnt3a has been implicated in periodontal development and homeostasis, as well as in cementum formation. Recently, we have reported that Wnt3a increases alkaline phosphatase expression through the induction of osterix (Osx) expression in dental follicle cells, a precursor of cementoblasts. However, the molecular mechanism by which Wnt3a induces Osx expression is still unknown. In this study, we show that Wnt3a-induced Osx expression was inhibited in the presence of p38 mitogen-activated protein kinase (MAPK) inhibitors (SB203580 and SB202190) at gene and protein levels, as assessed by real-time PCR and immunocytohistochemistry, respectively. Pretreatment of cells with Dickkopf-1, a potent canonical Wnt antagonist binding to LRP5/6 co-receptors, did not influence Wnt3a-mediated p38 MAPK phosphorylation, suggesting that Wnt3a activates p38 MAPK through LRP5/6-independent signaling. On the other hand, pretreatment with p38 MAPK inhibitors had no effects on the phosphorylated status of GSK3 beta and beta-catenin as well as beta-catenin nuclear translocation, but inhibited Wnt3a-mediated beta-catenin transcriptional activity. These findings suggest that p38 MAPK modulates canonical Wnt signaling at the beta-catenin transcriptional level without any crosstalk with the Wnt3a-mediated LRP5/6-GSK3 beta signaling axis and subsequent beta-catenin nuclear translocation. These findings expand our knowledge of the mechanisms controlling periodontal development and regeneration. (C) 2016 Elsevier Inc. All rights reserved.