Mechanical Memory and NF-κB Signaling in Dental Pulp Stem Cell Odontogenic Differentiation

Area of Science:

• Biomaterials Science
• Stem Cell Biology
• Regenerative Medicine

Background:

• Dental pulp stem cells (DPSCs) are crucial for dental tissue regeneration.
• Understanding how substrate properties influence DPSC behavior is vital for effective therapies.
• Stemness, senescence, and differentiation are key factors in DPSC function.

Purpose of the Study:

• To investigate the impact of substrate stiffness and dimensionality on DPSC stemness, senescence, and odontogenic differentiation.
• To examine the combined effects of priming duration and odontogenic induction.
• To elucidate the role of NF-κB signaling in these processes.

Main Methods:

• Fabrication of polydimethylsiloxane (PDMS) substrates with tunable stiffness (2-50 kPa) for 2D and 3D cultures.
• Priming DPSCs on substrates for 7 days followed by odontogenic induction.
• Analysis of gene expression (DMP-1, DSPP, NANOG, SOX-2, HAT-1, HDAC-1), immunofluorescence, and matrix mineralization.

Main Results:

• 2 kPa substrates significantly enhanced early odontogenic differentiation and stemness marker expression, while minimizing senescence.
• Soft substrates promoted mixed nuclear/cytoplasmic NF-κB localization, indicating a priming effect.
• 3D substrates showed delayed but robust differentiation, with increased epigenetic regulation and DNA repair markers (XRCC5), suggesting stabilized intermediate senescence.

Conclusions:

• Soft substrates (2 kPa) are optimal for preserving DPSC stemness and promoting early differentiation.
• 3D culture environments facilitate late-stage differentiation and a balanced senescence profile.
• Optimizing substrate properties and culture dimensionality is key for enhancing MSC-based regenerative therapies.