Neurogenic Induction Of Implanted Hdpscs Promotes Mandible Regeneration

Human dental pulp stem cells (hDPSCs) are widely recognized as a promising stem cell-based therapy for peripheral nerve injuries due to their ability to secrete neurotrophic factors (NTs). However, the influence of physical factors in matrix on hDPSC-derived NT secretion and its role in bone defects remains unclear. This study aims to investigate the influence of stiffness on NT secretion by hDPSCs and to determine whether this regulation following their transplantation in periapical mandible defects contributes to bone regeneration dependent on bone mesenchymal stem cells (BMSCs). First, we used RNA sequencing to screen the functional enrichment of differentially expressed genes in hDPSCs cultured on substrates with varying stiffness. We then assessed NT expression and secretion after neurogenic induction. Subsequently, we inhibited NTs in hDPSCs using siRNA, and the conditioned medium from these cells was used to induce osteogenic differentiation of BMSC. Additionally, we transplanted different stiffness gels mixed with hDPSCs into mouse molar periapical bone defects to analyze mandible regeneration in association with varying matrix stiffness. Our results highlight two points: 1) hDPSCs cultured on softer matrix tended to express and secrete more NTs, particularly following neurogenic induction; 2) The mixture of neurogenic-induced hDPSCs with soft gels enhanced healing of periapical bone defects compared to stiff gels, while NT knockdown diminished this effect. In conclusion, a soft matrix promotes NT secretion by transplanted hDPSCs, thereby contributing to periapical mandible regeneration . This study provides new strategies for the application of dental pulp stem cells in mandible regenerative medicine.