腭裂小鼠牙胚发育中β-连环蛋白的表达

doi:10.3969/j.issn.2095-4344.2012.50.007

摘要/Abstract

摘要：

背景：牙齿发育生物学中信号传导是热点问题，β-连环蛋白是Wnt信号传导通路中的关键效应因子，其在发育的牙胚中有普遍表达，并且在内釉上皮、釉结、星网状层、中间层的表达有时空变化。
目的：通过苏木精-伊红染色和免疫组化技术，观察牙胚在维甲酸诱导腭裂发生中的形态学变化及β-连环蛋白的表达变化。
方法：选取C57BL/6J近交系小鼠，按雌雄比2∶1于晚8时合笼，次日8时检查雌鼠，发现阴栓视为妊娠，定为E0 d。18只孕鼠随机分为3组：在E10 d，实验组以维甲酸100 mg/kg对孕鼠行一次性灌胃，制备腭裂动物模型；植物油对照组给予10 mL/kg橄榄油灌胃；空白对照组不做任何处理。
结果与结论：β-连环蛋白在空白对照组E13 d牙胚蕾状期、E14 d帽状期、E16 d钟状期上皮内均有表达，且空白对照组的表达随着牙胚发育的成熟而逐渐增加，实验组的变化趋势与空白对照组相同。3个时期的实验组β-连环蛋白在牙胚中的表达水平均高于空白对照组，植物油对照组和空白对照组表达无明显差异。提示维甲酸在诱导腭裂发生过程中，可能通过干扰上皮-间充质间的相互作用，上调β-连环蛋白在牙胚中的表达，使牙胚发育受阻。

Abstract:

BACKGROUND: In the biological study of dental development, signal transduction is a hot issue, and β-catenin is the key effector of the Wnt signaling pathway. β-catenin expresses in the tooth germ development and shows a temporal changes in the expression in the inner enamel epithelium, enamel knot, stellate reticulum, and intermediate layer.
OBJECTIVE: To investigate the morphologic changes of tooth germ development during cleft palate induced by all-trans retinoic acid in C57BL/6J mice, and to detect the effect of excess all-trans retinoic acid on the expression of β-catenin in tooth germ development.
METHODS: Eighteen pregnant mice which were divided into experimental group, vegetable oil control group and blank control group were examined by slight microscopy. Mice in the experimental group were treated with 100 mg/kg all-trans retinoic acid at E10 d to make cleft palate models. Mice in the vegetable oil control group received intragastric administration of 10 mL/kg olive oil. The blank control group had no treatment.
RESULTS AND CONCLUSION: During E13 d, E14 d, and E16 d, positive expression of β-catenin was found in the oral epithelium and the dental lamina, gradually became stronger where cells actively proliferated in the blank control group. The experimental group had similar changing tendency with the blank control group. The level of β-catenin in the blank control group was lower than that of the experimental group during all stages. The same expression level of β-catenin occurred both in the vegetable oil control group and blank control group. The changes of β-catenin expression induced by excess all-trans retinoic acid in the epithelium-mesenchymal interaction regulating morphogenesis of tooth germ may be related to the cleft palate induced by all-trans retinoic acid, and the expression of β-catenin displays an up-regulation tendency, which thus interferes with the development of tooth germ.

王利婷，宋容，王莎，司庆宗，张瑞，王建林，赵望泓. 腭裂小鼠牙胚发育中β-连环蛋白的表达[J]. 中国组织工程研究, 2012, 16(50): 9344-9348.

Wang Li-ting, Song Rong, Wang Sha, Si Qing-zong, Zhang Rui, Wang Jian-lin, Zhao Wang-hong. Expression of beta-catenin in tooth germ development of mice with cleft palate [J]. Chinese Journal of Tissue Engineering Research, 2012, 16(50): 9344-9348.

参考文献

引言

材料方法

讨论

文章快阅

延伸阅读

牙胚的发生是胚胎时期口腔牙源性上皮与下方来源于颅神经嵴细胞的外胚间充质互相作用的结果，局部增生的口腔上皮发出信号作用于下方间充质，引起特异性生牙部位的间充质凝集并促进细胞分化，从而启动牙胚发育目前牙胚发育的研究已从细胞水平深入到分子水平，研究发现，在牙胚形态发生和细胞分化过程中，有一系列信号分子调控，已知WNT经典通路参与了胚胎发育的过程，在其中扮演重要的角色近年，WNT在牙胚发育中的作用是研究热点，其多个相关因子在牙胚中有表达β-catenin(β连环蛋白)、APC结肠腺瘤性息肉病基因均为WNT经典通路的重要因子，近年关于β-catenin和APC的研究多在肿瘤发生方面，在牙胚发育方面的研究较少。

有研究者培养获得怀孕昆明小鼠，采用免疫组化SP法和DAB显色法检测不同时期胎鼠下颌第一磨牙胚内β-catenin和APC蛋白的表达情况，以细胞出现黄色颗粒为阳性表达。结果：①β-catenin在蕾状期时在口腔及牙板上皮中均弱阳性表达，牙蕾末端突起阳性表达，邻近间充质细胞为弱阳性，着色部位主要在细胞膜、细胞质及细胞核帽状期在口腔上皮、成釉器外釉上皮和星网状层表达弱阳性，内釉上皮阳性表达，尤其在内釉上皮中央处原发性釉结为强阳性，邻近牙乳头细胞中见弱阳性表达，着色在细胞膜、细胞质、细胞核钟状期在外釉上皮表达阳性，内釉上皮强阳性表达，星网状层弱阳性表达牙乳头内前成牙本质细胞阳性表达，着色在细胞膜、细胞质。②APC蕾状期时在口腔上皮，牙蕾上皮中均强阳性表达，着色在细胞膜、细胞质，在牙蕾周围间充质细胞的细胞膜可见弱阳性表达帽状期时在口腔上皮和星网状层表达阳性，内釉上皮表达强阳性，外釉上皮为弱阳性，牙囊细胞中可见弱阳性表达，着色在细胞膜、细胞质钟状期在内釉上皮阳性表达，在牙囊中的表达弱阳性，着色在细胞膜、细胞质在牙乳头中各期均无表达。③β-catenin和APC的表达有统计学相关性。结论：①β-catenin随着牙胚发育其表达逐渐增强，尤其以内釉上皮及釉结处的表达更为明显，而且早期位于细胞核及细胞质中这一事实推测其参与了牙胚早期的细胞增殖作用。②APC随着牙胚发育其表达逐渐减弱，而且在同一期内，内釉上皮及牙囊的表达较其它部位较强，这一现象提示其主要参与了牙胚早期细胞增殖，随着细胞增殖活性下降其作用减弱。③β-catenin与APC在牙胚发育过程的时空表达有重叠现象，表达结果分析有显著负相关性，这符合WNT经典信号通路中两者的作用关系，推测WNT经典信号通路参与了牙胚的发育，并主要作用在发育早期