Epithelium-specific Runx2 Knockout Mice Display Junctional Epithelium and Alveolar Bone Defects.

OBJECTIVE The aim of this investigation was to study the effects of Runt-related transcription factor 2 (Runx2) on the junctional epithelium and alveolar bone. METHODS The attachment level of the junctional epithelium and the resorption of alveolar bone were analyzed by histology and scanning electron microscopy. The expression of Amelotin was determined by immunohistochemistry, western blot, and real-time PCR. The ultrastructure of the dentogingival interface was observed by transmission electron microscopy. RESULTS The cKO mice demonstrated remarkable attachment loss, epithelial hyperplasia, and alveolar bone loss. The relative protein and mRNA expression of Amelotin was increased in the junctional epithelium of the cKO mice. The attachment apparatus of the cKO mice showed ultrastructural deficiency. CONCLUSIONS Loss of Runx2 led to the junctional epithelium and alveolar bone defects in mice. Runx2 may play a crucial role in maintaining the integrity of the dentogingival junction and the normal structure of alveolar bone.