小鼠牙胚发育过程中上游刺激因子1蛋白表达与分布模式的研究

Expression and localization of upstream stimulatory factor 1 in mice teeth development

目的:检测小鼠牙胚中上游刺激因子1(USF1)蛋白的表达及时空分布模式。方法:挖取P1和P11d小鼠第一磨牙胚,抽提总蛋白,Western blot检测USF1蛋白表达;制备E13、16、19及P1、5、8、11、21d和6月龄小鼠第一磨牙石蜡切片,免疫组化方法检测USF1蛋白的表达和分布。结果:Western blot从P11d小鼠第一磨牙胚中检测到相对分子质量约43000的特异性条带,但未从P1d检测到;免疫组化染色从P5d开始检测到较强的USF1阳性信号,持续至P11d,阳性信号仅定位于成牙本质细胞与成釉细胞胞质;而蕾状期,帽状期,钟状期牙胚中未检测到阳性信号,并且在牙齿萌出后(P21d与6月龄),牙齿中USF1阳性信号再次消失。结论:牙胚中有USF1蛋白表达,仅定位于分泌期的成牙本质细胞和成釉细胞,表达模式具有显著的时空特异性。

Objective.To detect the expression of upstream stimulatory factor 1 （ USF1 ） and its tempo-spatial distribution during mice teeth development. Methods： Total protein was extracted from P1 and P11 d mice first molar teeth germ, and Western blot for USF1 was undertaken. Paraffin sections of first molar teeth germs from El3, 16, 19, P1,5, 8, 11, 21 d and 6-month-old adult mice were prepared respectively and immunohistochemical staining was carried out. Results： Western blot analysis identified one Mr43 000 protein from Pll d mice teeth germs, but none from Pld mice. Immunohistochemically, evidently positive staining for USF1 in mice teeth germs began from P5 d, and extended to P11 d, which was mainly confined to the cytoplasm of secreting ameloblasts and odontoblasts, but no staining in bud, cap and early bell stages of tooth germ. However, after tooth eruption on P21 d, USF1 became negative again, although it was still positive in the adjacent muscles, and the same result was observed in adult mice tooth. Conclusion： USF1 is expressed in tooth germ, which localizes solely in secreting ameloblasts and odontoblasts, and its expression was quite dynamic during mice tooth development.