CCR5-CCL Axis in PDL during Orthodontic Biophysical Force Application

Area of Science:

• Biomedical Science
• Orthodontics
• Cell Biology

Background:

• Orthodontic tooth movement (OTM) relies on molecular signals from the periodontal ligament (PDL).
• Key molecules orchestrating PDL responses to orthodontic forces remain largely unknown.

Purpose of the Study:

• To investigate the role of CC chemokine receptor 5 (CCR5) in the cellular response to orthodontic forces.
• To explore the potential of the CCR5-CCR5 ligands axis as a therapeutic target for OTM.

Main Methods:

• In vivo OTM model in rats with differential display-polymerase chain reaction.
• In vitro studies applying compression and tension forces to human PDL cells.
• Analysis of gene and protein expression, including CCR5, its ligands, RANKL, IL12, Runx2, and osteoprotegerin.
• CCR5 gene silencing to assess its specific role.

Main Results:

• CC chemokine receptor 5 (CCR5) expression was significantly increased in PDL during OTM in vivo.
• Both compression and tension forces on human PDL cells upregulated CCR5 and its ligands.
• Under tension, CCR5 influenced osteoblast differentiation factors (Runx2) and osteoclast inhibitory factors (IL12).
• Under compression, CCR5 modulated RANKL expression, an osteoclastogenesis-inducing factor.

Conclusions:

• The CCR5-CCR5 ligands axis in PDL cells plays a critical role in periodontal tissue remodeling during OTM.
• This axis represents a potential therapeutic target for improving the efficiency of orthodontic treatments.