Objective: 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.
Methods: 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.
Results: 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.
Conclusions: The multi-differentiation potential of Gli1+ PDL cells was revealed, indicating that Gli1+ cells are an important cell source for periodontal development.
目的 利用转基因小鼠探究牙周膜内Gli 阳性（Gli1+）细胞的表达分布以及Gli1+细胞在牙周组织发育过程中的作用。方法 收集3、6和8周龄Gli1lacZ/+小鼠下颌骨，通过β-半乳糖苷酶组织化学染色（X-gal染色）观察牙周膜内Gli1+细胞的时间和空间分布特点。然后，通过注射他莫昔芬诱导3周龄Gli1-CreERT2/+;R26RtdTomato/+小鼠表达红色荧光蛋白tdTomato，对Gli1+细胞及其子代细胞（tdTomato+细胞）进行动态追踪。结果 3周龄小鼠牙周膜内分布大量Gli1+细胞，随着年龄的增长，Gli1在牙周膜内的数量逐渐减少（P<0.05）。tdTomato+细胞随着诱导时间的延长，数量逐渐增加（P<0.05），且逐渐分化成熟为成纤维细胞、牙骨质细胞和骨细胞。结论 牙周膜内Gli1+细胞具有多向分化的潜能，是牙周组织发育过程中重要的细胞来源。.
Keywords: Gli1; development; lineage tracing; periodontal tissue; stem cell.