不同发育阶段恒牙牙髓组织中VEGF及受体的表达

Expression of VEGF and VEGFR in the pulp of different developmental state of permanent teeth

目的:探讨人年轻恒牙和成熟恒牙牙髓组织中VEGF及其受体Flt-1、Flk-1的组织学和分子水平的表达。方法:将因正畸治疗需要而拔除的人健康前磨牙分为根尖开放的年轻恒牙和根尖闭合的成熟恒牙,每组各15例。采用免疫组织化学方法检测VEGF及受体Flt-1、Flk-1蛋白的表达;RT-PCR法检测人年轻恒牙和成熟恒牙牙髓组织中VEGF、Flt-1、Flk-1的mRNA表达情况。结果:免疫组化显示年轻恒牙牙髓VEGF,Flk-1阳性表达的平均光密度(D)值高于成熟恒牙(P<0.05),而Flt-1的表达低于成熟恒牙(P<0.05)。RT-PCR结果显示人年轻恒牙和成熟恒牙牙髓组织均可表达VEGF、Flt-1、Flk-1的mRNA,产物大小分别为145 bp、169 bp和162 bp,且年轻恒牙牙髓组织VEGF、Flt-1、Flk-1的mRNA相对含量分别是成熟恒牙的1.7倍、0.6倍和1.5倍(P<0.05)。结论:在人健康恒牙的牙髓组织中,VEGF、Flt-1、Flk-1的表达随根尖孔的闭合与否呈现不同表达特征,提示在恒牙的不同发育阶段可通过调控上述基因诱导修复性牙本质形成。

Objective： To investigate the histological and molecule level expression and distribution of VEGF, Flt-1, Flk-1 in the pulp of young and mature permanent teeth and explore the role of VEGF, Flt-1, Flk-1 in the permanent root development. Methods： Young and mature permanent teeth were collected for orthodontic reasons,each group included 15 teeth. The expression and localization of VEGF, Fit-1, Flk-1 were studied with immunohistochemistry. VEGF, Flt-1, Flk-1 mRNA levels of young and mature permanent teeth dental pulp were assayed by RT-PCR. Results： Immunohistochemical staining detected the expression of VEGF and Flk-1, they were more positive in young permanent than the mature （P 〈 0.05 ） ; while Flt-1 was more positive in the mature; RT-PCR demonstrated VEGF, Fh-1, Flk-1 mRNA expression in young and mature permanent teeth pulp tissue with 145 bp, 169 bp and 162 bp transcript respectively, and rela- tive content of VEGF, Flt-1, Flk-1 in young permanent teeth were 1.7, 0.6 and 1.5 times in mature ones. Conclusion： The expression of VEGF, Flt-1, Flk-1 in the pulp of young and mature permanent teeth showed different characteristics, which suggests that the reparative dentine formation of permanent teeth can be induced by regulating the upper genes at different development stages.