Effect of Wnt/β-catenin signaling pathway on repair and regeneration after dentin-pulp injury

The Wnt/β-catenin signaling pathway performs multiple essential functions during tooth development. Several Wnt/β-catenin signaling pathway components are expressed in the dental epithelium and mesenchyme during tooth development in humans and mice. Functional studies and experimental analyses in relevant animal models have confirmed the regulatory role of the Wnt/β-catenin signaling pathway on developing tooth formation and adult dental homeostasis. In this study, we used the adult mouse incisor as a model to explore the effect of the Wnt/β-catenin signaling pathway on the repair and regeneration of dental pulp stem cells after injury. We established the dentin-pulp injury models successfully in two different ways and observed an obvious injury in the proximal region of the adult mouse incisor in each group. Faster repair and regeneration were detected after Wnt/β-catenin signaling activation and vice versa, indicating that Wnt/β-catenin signaling is required for cell proliferation and odontoblast differentiation. The same results were further verified by culturing mouse DPSCs in vitro. In our experiments, we found that Wnt10a also showed significant expression when the Wnt/β-catenin signaling pathway was activated and further demonstrated that Wnt10a-mediated Wnt/β-catenin signaling plays a positive regulatory role to regulate DPSCs proliferation and odontoblast differentiation and promoting the repair process of incisor injury. This study highlights the crucial role of the Wnt/β-catenin signaling pathway in the tooth injury and repair and shed new lights on the discovery of novel molecular mechanisms associated with tooth regeneration.