Temporal and spatial distribution of Gli1+ cells and their function during periodontal development

Abstract

This study aimed to investigate the distribution of Gli1+ cells in the periodontal ligament (PDL) and to evaluate their contribution in the development of periodontal tissue by using transgenic mouse lines. Gli1lacZ/+ mice were harvested at different ages (3, 6, and 8 weeks), and the temporal and spatial distribution patterns of Gli1+ PDL cells were revealed by X-gal staining. Afterward, 3-week-old Gli1-CreERT2/+;R26RtdTomato/+ mice were administered with tamoxifen, and the fates of Gli1+ cells and their descendants were traced during periodontal development. A large number of Gli1+ cells were detected in the PDL of the 3-week-old mice; however, their number significantly decreased from 3 weeks to 8 weeks (P<0.05). Cell lineage tracing data showed that the descendants of Gli1+ cells dramatically increased from 3 weeks to 8 weeks (P<0.05) and gradually differentiated into fibroblasts, cementocytes, and osteocytes. The multi-differentiation potential of Gli1+ PDL cells was revealed, indicating that Gli1+ cells are an important cell source for periodontal development.