Ling Song; Lan Liu; Liying Yang; Jinhua Liu; Tao Li & Xijiao Yu

Currently, the most evident action of PLAP1 is the inhibition of mineralization in the periodontal ligament. The objective of this study was to investigate the expression levels of Periodontal Ligament-Associated Protein 1 (PLAP1) throughout tooth development and its impact on the development of teeth, periodontal ligament, and bone. The expression profile of PLAP1 throughout several stages of mandibular tooth development was examined using immunohistochemical staining in mice at gestational ages of 13.5, 14.5, and 16.5 days, as well as at postnatal ages of 5.5, 10.5, 15.5, 25.5, 30.5, and 60.5 days. The impact of Plap1 gene deletion on the development of teeth and long bones was examined using HE staining and micro-CT. PLAP1 was consistently expressed throughout tooth development, with varying expression intensity corresponding to developmental stages. It impeded the mineralization of the periodontal ligament. The development of tooth, maxilla, and long bone in Plap1 knockout mice was not significantly different from that of their wild-type counterparts, suggesting the possible presence of compensatory mechanisms. PLAP1 played a crucial role in periodontal ligament mineralization, and did not induce variations in tooth and femur development.

KEY WORDS: Periodontal ligament-associated protein-1; Gene knockout mouse; Tooth development; Periodontal ligament.

SONG, L.; LIU, L.; YANG, L.; LIU, J.; LI, T. & YU, X. PLAP1 is involved in the process of tooth development and regulates the width of periodontal ligament. Int. J. Morphol. 43(5):1674-1684, 2025.