摘要
目的:检测凋亡调控抑制蛋白Bcl-2在成釉细胞分化、分泌过程中的表达,观察细胞超微结构的变化,探讨Bcl-2和细胞凋亡在该过程的可能作用。方法:制备出生后2、5、7、9、14 d不同发育阶段的BALB/C小鼠下颌第一磨牙牙胚标本,采用原位末端标记法(TUNEL法)和PV免疫组织化学技术观察成釉细胞分化、分泌和釉质发育完成各阶段细胞凋亡以及Bcl-2的表达情况;透射电镜观察细胞超微结构的变化。结果:出生后第2～5天,小鼠下颌第一磨牙成釉细胞处于分化期,超微结构可见胞浆内有高尔基复合体和线粒体,并有细胞增生的核分裂;免疫组化结果显示Bcl-2阳性表达,TUNEL检测结果发现部分细胞胞核阳性表达,提示细胞凋亡的存在;出生后第7天,成釉细胞已开始分泌,可见新形成的釉质,胞核远基底排列,胞核附近可见大量线粒体,胞质内可见大量高尔基复合体和粗面内质网,胞浆呈Bcl-2强阳性表达,TUNEL检测结果发现少量细胞胞核阳性表达;出生后14 d,釉质发育完成,成釉细胞变短,间隙变大,细胞器数量减少,核膜逐渐不清,核糖体脱颗粒水肿,呈现凋亡征象,胞浆未见Bcl-2阳性表达。结论:细胞凋亡在釉质发育的各期皆有表达,Bcl-2作为凋亡抑制基因可能参与了成釉细胞的分化、分泌的调控。
AIM： To observe Bcl-2 expresion during amelogenesis in developing mouse molars. METH- ODS ： First molar germs of postnatal 2 - 14 d BALB/C mice were extracted. The morphology and distribution of amelo- blasts in the tooth germ were examined by light and transmission electron microscopy. PV two-step immunohistochemi- cal method was used to detect the expression of Bcl-2 protein. Apoptosis was identified by the terminal deoxy-transfer- ase （TdT） -mediated dUTP-biotin nick end labeling （TUNEL） method. RESULTS： Bcl-2 positive cells was detected in the proliferating pre-ameloblasts and secretory stage ameloblasts, but the immunoreactivity disappeared when enamel was secreted fully. TUNEL staining of apoptosis cells was observed in every stage of ameloblasts, especially in the ma- ture stage. Uhrastructural changes of apoptosis in ameloblasts were observed in every stage of ameloblast development. CONCLUSION： The results indicated that Bcl-2 may play a role in the process of amelogenesis with its proposed mechanisms of action in the control of apoptosis.
出处
《牙体牙髓牙周病学杂志》
CAS
北大核心
2012年第12期695-698,共4页
Chinese Journal of Conservative Dentistry
