Gli1阳性细胞在牙周组织发育中的时空分布特点及功能研究

Temporal and spatial distribution of Gli1+cells and their function during 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Gli1^lacZ/+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-Cre^ERT2/+;R26R^tdTomato/+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。

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 Gli1^lacZ/+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-Cre^ERT2/+;R26R^tdTomato/+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.Conclusion The multidifferentiation potential of Gli1^+PDL cells was revealed,indicating that Gli1+cells are an important cell source for periodontal development.