Plexin-B2 Mediates Orthodontic Tension-Induced Osteogenesis via the RhoA/F-Actin/YAP Pathway

Area of Science:

• Biomaterials Science
• Cell Biology
• Orthodontics

Background:

• Periodontal ligament stem cells (PDLSCs) are crucial for maintaining periodontal health and regeneration.
• Mechanical forces, such as those experienced during orthodontic tooth movement (OTM), significantly influence PDLSC behavior and bone remodeling.
• Understanding the molecular mechanisms underlying mechanotransduction in PDLSCs is vital for optimizing orthodontic treatments and regenerative strategies.

Purpose of the Study:

• To investigate the role of Plexin-B2 in tension-induced osteogenesis of PDLSCs.
• To elucidate the biomechanical mechanisms by which Plexin-B2 mediates cellular responses to mechanical tension.
• To assess the impact of Plexin-B2 on new bone formation during orthodontic tooth movement.

Main Methods:

• In vitro studies using cyclic tension on PDLSCs to analyze Plexin-B2 expression and osteogenic potential.
• In vivo OTM models in mice utilizing lentivirus and adeno-associated viruses (AAVs) for Plexin-B2 manipulation.
• Molecular analyses including Western blotting, immunofluorescence for F-actin and YAP, and RhoA signaling pathway assessment.

Main Results:

• Cyclic tension increased Plexin-B2 expression in PDLSCs.
• Plexin-B2 knockdown impaired osteogenic protein expression and new bone formation during OTM.
• Plexin-B2 deficiency affected RhoA signaling, F-actin organization, and YAP nuclear translocation, which were partially reversible upon RhoA manipulation.

Conclusions:

• Plexin-B2 is a key mediator of tension-induced osteogenesis in PDLSCs.
• The RhoA signaling pathway, F-actin dynamics, and YAP nuclear translocation are critical components of Plexin-B2's mechanotransduction pathway.
• Targeting Plexin-B2 may offer novel therapeutic strategies for enhancing bone regeneration during orthodontic interventions.