两种钙黏蛋白在小鼠牙齿发育期的时间和空间表达

Spatiotemporal expression pattern of E-cadherin and P-cadherin during mouse tooth development

目的:观察E-钙黏蛋白及P-钙黏蛋白在牙齿胚胎发育早期的时间和空间分布。方法:取胚胎第12.5天至出生后第3.5天的CD1型小鼠下颌骨标本,免疫荧光二步法及共聚焦荧光显微镜检测E-钙黏蛋白及P-钙黏蛋白在下颌第一磨牙牙胚发育不同时期的表达情况,通过HE染色显示组织形态。结果:两种钙黏蛋白在牙胚发育过程中广泛表达于上皮组织中,前成釉细胞在极化过程中E-钙黏蛋白表达增强、P-钙黏蛋白表达减弱,P-钙黏蛋白在牙胚发育初期即出现于牙胚上皮表层,并在分泌期成釉细胞中表达。结论:钙黏蛋白在牙胚早期发育过程中存在空间、时间上的表达差异,提示两种钙黏蛋白在牙冠形成期间行使不同的功能,推测P-钙黏蛋白参与了釉质的分泌与矿化过程。

Objective： To investigate the expression patterns of E-cadherin and P-cadherin in murinetooth germs at early developmental stages. Methods： Mandible samples of CD1 mice from embryonic day12. 5 to postnatal day 3. 5 were collected. The expressions of E-cadherin and P-cadherin in murine mandibular first molar germs were detected by immunofluorescence and observed under confocal fluorescence microscope. HE staining was performed for tissue morphology. Results： Both E-cadherin and P-cadherin were widely expressed in the epithelial tissues through early developmental stages. The E-cadherin expression was increased in polarizing pre-ameloblasts,whereas the P-cadherin expression declined. The expression of the P-cadherin could be detected in epithelial tissues before bud stage,and expressed in mature ameloblasts at secretory stage. Conclusion： The E-cadherin and P-cadherin expressed in different spatiotemporal expression patterns,indicating their individual functions during tooth development. P-cadherin might function in the secretion and mineralization of enamel.