The potential role of SCF combined with DPCs in facial nerve repair

Facial nerve injuries lead to significant functional impairments and psychological distress for affected patients. Effective repair of these injuries remains a challenge. For longer nerve gaps, the regeneration outcomes after nerve grafting remain suboptimal due to limited sources and postoperative immune responses. Tissue engineering techniques are conventional methods for repairing peripheral nerve defects. This study explores the potential of dental pulp cells (DPCs) combined with stem cell factor (SCF) to enhance neurogenic differentiation and improve facial nerve regeneration. DPCs were isolated from rabbit dental pulp, the pluripotency of the cells was identified from three perspectives: osteogenic differentiation, adipogenic differentiation, and neurogenic differentiation. In vivo experiments involved injuring the buccal branch of the facial nerve in New Zealand white rabbits, followed by treatment with PBS, DPCs, SCF, or SCF + DPCs. Functional recovery was assessed over 12 weeks, with SCF + DPCs demonstrating the most significant improvement in whisker movement scores. Histomorphological evaluations revealed enhanced myelinated fiber density and axonal morphology in the SCF + DPCs group. RNA sequencing identified 608 differentially expressed genes, with enrichment in the TGF-β signaling pathway. In in vitro experiments, we demonstrated from multiple angles using Western blot analysis, Real-time quantitative polymerase chain reaction (QPCR) analysis, and immunofluorescence staining that SCF can promote the neurogenic differentiation of DPCs through the TGF-β1 signaling pathway. Our findings indicate that the combination of SCF and DPCs offers a promising strategy for enhancing facial nerve repair.