Integrin-Associated Signalling Regulates Jagged1-Induced Osteogenic Differentiation of Human Dental Pulp Stem Cells

Aim To investigate the role of integrin-associated adhesion signalling in Jagged1-driven osteogenic differentiation and to determine the specific contribution of integrin β3 (ITGβ3). Methodology RNA sequencing data from Jagged1-activated human dental pulp cells were analysed to identify changes in integrin-associated signalling. Jagged1-induced Notch activation and ITGβ3 expression were validated by quantitative real-time polymerase chain reaction and immunofluorescence. Functional inhibition of integrin activity was performed using the αvβ3 antagonist cilengitide, and the specific role of ITGβ3 was examined using ITGβ3-targeting siRNA. Apoptosis was evaluated by flow cytometry, migration by a wound-healing assay, and osteogenic differentiation by Alizarin Red S staining and osteogenic gene expression. Results RNA sequencing analysis revealed enrichment of extracellular matrix- and integrin-associated pathways among Jagged1-responsive genes in human dental pulp stem cells (hDPSCs), with ITGβ3 identified as a prominently upregulated integrin subunit. Jagged1 induced ITGB3 mRNA expression in parallel with dose- and time-dependent increases in the Notch target genes HES1 and HEY1 , and increased ITGβ3 protein expression was further confirmed by immunofluorescence. Pharmacological inhibition with cilengitide did not affect viability, proliferation, or migration, but significantly suppressed basal and Jagged1-induced mineralisation and reduced RUNX2 expression. High-dose cilengitide (1000 nM) increased late-stage apoptosis under Jagged1 stimulation. In contrast, ITGB3 silencing attenuated basal osteogenic differentiation but did not impair Jagged1-induced mineralisation. Conclusion Jagged1-induced osteogenic differentiation of hDPSCs requires integrin-dependent adhesion signalling but is not exclusively dependent on ITGB3 transcription. These findings support integrin–Notch crosstalk as a regulatory mechanism in hDPSC osteogenesis and provide a rationale for designing regenerative dental biomaterials that combine Notch-activating and adhesion-supportive cues.