Oct4 Promotes Dental Pulp Regeneration Through Up-Regulating Per1

Mesenchymal stem cells (MSCs) represent a cornerstone of regenerative medicine, yet their clinical utility is frequently limited by replicative senescence. This study was designed to establish an in vitro replicative senescence model using stem cells from apical papilla (SCAP), investigate the regulatory roles of OCT4 and PER1 in odontogenic differentiation of senescent SCAP and evaluate their therapeutic potential for pulp regeneration. A three-dimensional culture system was implemented with three experimental groups: P15 SCAP overexpressing OCT4 (P15OCT4+), GFP-transduced SCAP in P5 (P5GFP+) and P15 (P15GFP+). Biological properties of cells in three groups were systematically analyzed using flow cytometry, qRT-PCR, Western blotting, and immunofluorescence staining. To explore the OCT4-PER1 interaction, dual-luciferase and ChIP assays were utilized. Cell-Matrigel constructs were subcutaneously implanted in nude mice for 12 weeks to assess pulp regeneration capacity. Our findings demonstrate that OCT4 overexpression effectively reverses cellular senescence in SCAP and enhances their pulp regeneration potential. Mechanistic investigations revealed that OCT4 directly binds to the PER1 promoter, driving its transcriptional activation. This OCT4-PER1 regulatory axis was shown to critically mediate the restoration of odontogenic differentiation capacity in senescent SCAP. This study identifies a novel OCT4/PER1-mediated mechanism that rejuvenates senescent SCAP in 3D culture systems, significantly improving their regenerative competence. The transcriptional activation of circadian regulator PER1 by OCT4 not only ameliorates senescence-associated phenotypes but also restores the odontogenic differentiation potential essential for functional pulp regeneration. These findings provide a strategic framework for therapies in regenerative medicine.