Enhanced junctional epithelial permeability in TRPV4-deficient mice

Area of Science:

• Oral biology
• Epithelial biology
• Mechanobiology

Background:

• The junctional epithelium forms a critical barrier between the oral cavity and teeth, defending against mechanical stress and bacterial invasion.
• The role of mechanical stimuli in regulating epithelial functions, particularly within the junctional epithelium, remains largely unexplored.
• Transient Receptor Potential Vanilloid 4 (TRPV4) is a known mechanosensitive ion channel with expression noted in the junctional epithelium.

Purpose of the Study:

• To investigate the role of TRPV4 in the junctional epithelium.
• To determine the relationship between TRPV4 and junctional complexes.
• To elucidate the impact of TRPV4 on epithelial barrier function and periodontal health.

Main Methods:

• Histological analysis of junctional epithelium in TRPV4-deficient (TRPV4-/-) and wild-type (TRPV4+/+) mice.
• Assessment of intercellular space and exogenous tracer penetration in the junctional epithelium.
• Immunoreactivity analysis for adherens junction proteins.
• Evaluation of bone volume loss in a mouse periodontitis model.

Main Results:

• TRPV4-/- mice exhibited wider intercellular spaces in the junctional epithelium compared to wild-type mice.
• Increased tracer penetration was observed in the junctional epithelium of TRPV4-/- mice.
• Suppressed immunoreactivity for adherens junction proteins was found in TRPV4-/- mice.
• TRPV4-/- mice showed greater bone volume loss in a periodontitis model, indicating compromised epithelial barrier function.

Conclusions:

• TRPV4 plays a vital role in forming adherens junctions within the junctional epithelium, thereby regulating its permeability.
• TRPV4 is identified as a potential pharmacological target for combating periodontal diseases.