Immunohistochemical analysis of histone-deacetylases in tongue and oral mucosa of mice during postnatal development and aging.

OBJECTIVE: Histone deacetylases (HDACs) act as transcriptional repressors and play essential roles in mammalian development. However, data on the expression and subcellular localization of HDACs in the tongue and oral mucosa remain limited. This study aimed to investigate the spatiotemporal expression patterns of HDACs in the mouse tongue and oral mucosa during postnatal development and aging. METHODS: Tongue and oral mucosal tissues were collected from C57BL/6 J mice at postnatal day 1 (P1), postnatal day 21 (P21), 3 months, 10 months, and 18 months. Hematoxylin and eosin (H&E) staining and immunohistochemistry (IHC) were performed to assess tissue morphology and HDAC expression. RESULTS: HDAC1 and HDAC6 were not detected in either tissue. In contrast, HDAC2 showed distinct nuclear localization in epithelial cells. The remaining HDAC isoforms exhibited diverse spatiotemporal expression patterns with marked age-related changes. Specifically, HDAC2-5 and HDAC7-11 were expressed at higher levels in adult mice (3 and 10 months) than at P21 and 18 months. In addition, these HDACs were not detected in basal epithelial cells at P21 and 18 months. CONCLUSION: This study characterizes the spatiotemporal expression patterns of HDAC family members in the mouse tongue and oral mucosa during postnatal development and aging, providing a valuable reference for future studies on the functional roles of HDACs in oral tissue homeostasis and aging.