Jun家族蛋白在釉质发育中的表达及对amelogenin的调控作用

The expression of Jun family proteins in enamel development and the effect on amelogenin

目的:探讨Jun家族蛋白Jun B、c-Jun和Jun D在小鼠釉质发育中的作用。方法:应用免疫组化染色检测Jun B、c-Jun和Jun D在不同发育阶段小鼠牙胚成釉细胞中的表达;分别以0.5μg和2.0μg的Jun B、c-Jun和Jun D转染小鼠成釉细胞后,运用RT-PCR观察其对釉原蛋白amelogenin mRNA表达的影响。结果:免疫组化染色结果显示:釉质分泌期时,Jun B在成釉细胞核中无显著表达,Jun D呈弱表达,而c-Jun表达明显;釉质转型期时,Jun B和Jun D表达增强且Jun D早于Jun B,c-Jun持续表达明显;在釉质成熟期时,Jun B、c-Jun和Jun D均显著表达。RT-PCR检测显示:高剂量Jun B可明显抑制amelogenin的表达(P<0.05);低剂量c-Jun可明显促进amelogenin的表达(P<0.05);Jun D对amelogenin的表达无显著影响。结论:在釉质发育早期,c-Jun可通过上调釉原蛋白的表达参与釉质发育。在釉质发育后期,Jun B可通过抑制釉原蛋白的分泌促进釉质的成熟。Jun D对amelogenin表达无显著影响。

AIM： To investigate the role of Jun family proteins in enamel development of mouse. METH- ODS： Immunohistochemical staining was applied to detect the expression of JunB, c-Jun and JunD in mouse tooth germ ameloblasts. RT-PCR was employed to evaluate the effect on the mRNA expression of amelogenin after transfection of the amelohlasts by JunB, C - Jun and JunD at 0.5μg and 2.0 μg respectively. RESULTS： At the secretion stage, JunB was not expressed and JunD was weakly expressed in ameloblasts nuclei, but c-Jun was obviously expressed. At the transition stage, JunB and JunD expression were increased and JunD was earlier than JunB. e-Jun continuously exhibited strong expression. At the maturation stage, all of the proteins were strongly expressed. Transfee- tion results showed that high dose of JunB inhibited the expression of amelogenin. Low dose of e - Jun evidently en- hanced the expression of amelogenin JunD had no significant effect on amelogenin expression. CONCLUTION ： c-Jun may up-regulate the expression of amelogenin at the early stage of enamel development. JunB may suppress the secretion of amelogenin and promote the maturation of enamel at the late stage of enamel development. JunD has no significant effect on amelogenin.