EMMPRIN在小鼠磨牙牙胚形态发生过程中的表达

Expression of extracellular matrix metalloproteinase inducer in morphogenesis of tooth germs in mouse molars

目的研究细胞外基质金属蛋白酶诱导因子EMMPRIN(basigin/CD147)在小鼠磨牙牙胚发育各阶段的表达,探讨其可能的生物学作用。方法选择不同胎龄(E11、E13、E14、E15、E16、E18)和出生后1 d(P1)小鼠作为实验对象。Real-Time PCR定量检测小鼠牙胚发育各阶段下颌(E11和E13)及牙胚(E14、E15、E16、E18和P1)组织中EMMPRIN mRNA表达。原位杂交和免疫荧光染色观察EMMPRINmRNA和蛋白在牙胚组织及相应发育阶段的颌面部发育器官中的定位表达。结果 Real-Time PCR结果显示,E13胎鼠下颌标本中EMMPRIN mRNA的表达约为E11胎鼠1.6倍(P<0.01);P1小鼠牙胚组织中EMMPRIN mRNA表达约为E14胎鼠的2倍(P<0.01);EMMPRIN mRNA表达随牙胚组织发育呈现递增趋势。原位杂交和免疫荧光染色观察显示,在E14胎鼠牙胚组织中EMMPRIN mRNA和蛋白表达定位一致,但E15、E16、E18胎鼠EMMPRIN mRNA与蛋白表达定位有所不同;相应发育时段胎鼠下颌骨的Meckel软骨(E14)、视网膜(E15)、大脑血脑屏障(E15)及颚骨骨化中心(E16)中EMMPRIN蛋白表达均呈现强荧光信号。结论 EMMPRIN的表达贯穿于早期牙胚发生和发育的多个阶段,但牙胚发育帽状期和钟状期阶段EMMPRIN mRNA与蛋白表达并不完全一致。EMMPRIN有可能以外分泌或旁分泌方式,通过调控上皮间质的相互作用参与牙胚发育及形态发生。

Objective To explore expression of extracellular matrix metalloproteinase inducer（EMMPRIN） in different stages of tooth germ development of mouse low first molar,and speculate the possible biological function of EMMPRIN.Methods Mice at different gestational ages（E11,E13,E14,E15,E16,and E18） and postnatal 1 d（P1） were selected.Expressions of EMMPRIN mRNA of the mandible（E11 and E13） and tooth germ（E14,E15,E16,E18,and P1） in different stages in mouse tooth germ development were measured by using quantitative real-time PCR.Localization of EMMPRIN mRNA and protein expression in the developing tooth germ and other cranio-facial organs at different stages were observed by using in situ hybridization and immunofluorescence. Results In mandible samples,EMMPRIN mRNA expression of E13 fetal mouse was about 1.6 times than that of E11 fetal mouse（P0.01）.In tooth germ,EMMPRIN mRNA expression of P1 mouse was about 2 times than that of E14 fetal mouse（P0.01）.EMMPRIN mRNA level in tooth germ seemed to increase gradually during tooth germ development.Under in situ hybridization and immunofluorescence,in E14 fetal mouse tooth germ,localization of EMMPRIN mRNA and protein expression were consistent.But in E15,E16,and E18 fetal mouse tooth germ,localization of EMMPRIN mRNA and protein expression were different.In corresponding stages,EMMPRIN protein expression showed strong fluorescence in mandible Meckel cartilage（E14）,retina（E15）,brain blood-brain barrier（E15）,and jaw bone ossification center（E16）. Conclusion EMMPRIN is expressed throughout the different early stages of tooth germ development,but the expression pattern of EMMPRIN mRNA do not coincide with that of EMMPRIN protein completely at the cap stage and the bell stage of tooth germ development.EMMPRIN may act through possible exocrine/paracrine mechanism in regulating the epithelial mesenchymal interaction,which consequently contributes to the development and further morphogenesis of tooth germ.