The Junctional Epithelium Attachment Is Regulated by Wnt Signaling.

This article investigates the role of Wnt/β-catenin signaling in maintaining the barrier functions of the junctional epithelium (JE), a tissue critical for tooth attachment and defense against periodontal disease. Using both a topical inhibitor (C59) of the Wntless protein, which impairs Wnt protein secretion, and a genetic model deleting Wntless in osteocalcin-expressing cells, the study demonstrates that reduced Wnt/β-catenin signaling leads to decreased JE cell proliferation, increased apoptosis, downregulation of hemidesmosomal attachment proteins (such as laminin 5, integrin β4, and plectin), disruption of collagen organization, and increased immune cell infiltration. These changes result in JE breakdown, attachment loss, and alveolar bone resorption, hallmarks of periodontitis. The findings suggest that Wnt/β-catenin signaling is essential for JE homeostasis and that modulating this pathway may offer therapeutic potential for restoring JE integrity after injury or disease.