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The role of basement membrane type heparan sulfate proteoglycan, perlecan, in epithelial morphogenesis -transgenic mice overexpressing perlecan in the epithelial cells-

基底膜型硫酸乙酰肝素蛋白聚糖、基底膜蛋白聚糖在上皮形态发生中的作用 -在上皮细胞中过度表达基底膜蛋白聚糖的转基因小鼠-

基本信息

批准号：
17591902
负责人：
IDA Hiroko
金额：
$ 2.3万
依托单位：
Niigata University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

项目摘要

Perlecan, a basement membrane-type heparan sulfate proteoglycan, is localized in the intercellular space of the enamel organ. Hence, it has been suggested to play an important role in tooth morphogenesis. To elucidate the function of perlecan in odontogenesis, we generated transgenic mice overexpressing perlecan in the epithelial cells using a keratin 5 promoter, and examined the effect of perlecan overexpression on enamel organ formation. Transgenic mice were generated by pronuclear microinjection of fertilized C57BL/C3H F1 oocytes with the DNA construct, and they express the entire perlecan core protein under the control of a bovine keratin 5 promoter. Their molar tooth germs were studied by EM, immunohistochemistry, and RT-PCR for perlecan and tooth germ-related molecules.Perlecan was immunohistochemically confirmed to be expressed strongly in epithelial tissues, including the enamel organ of Tg mice. Morphologically, the stellate reticulum of the Tg molars showed widened intercellu … More lar spaces and thick, irregularly shaped dental laminae at the embryonic stage (E13-E18). In postnatal day 1 (P1) Tg mice, the enamel organ was obviously lacking cell density and was less vascularized. Finally, the crown shape of Tg molars became dull-ended, with incomplete crystallization and divergent tooth roots in mandibular molars. mRNA expression levels for FGF-2, TGF-β1, and PKC-a were elevated in Tg tooth germs at P1.From these results, it was suggested that perlecan may control the space arrangement of stromata by binding and releasing of growth factors, and it may act as a carrier for nutrient transport by diffusion within the epithelial milieu. Also in the process of odontogenesis, perlecan might contribute in forming highly hydrated circumstances to realize cell growth and differentiation in the enamel organ. However, the time schedule of the intraepithelial expression of perlecan seems to be critically controlled, because a constant overexpression perlecan has interfered normal tooth morphogenesis. Less

串珠素是一种基底膜型硫酸乙酰肝素蛋白多糖，定位于成釉器的细胞间隙。因此，它被认为在牙齿形态发生中起重要作用。为了阐明串珠素在牙齿发生中的功能，我们使用角蛋白5启动子在上皮细胞中过表达串珠素产生转基因小鼠，并检查串珠素过表达对成釉器官形成的影响。通过原核显微注射受精的C57 BL/C3 H F1卵母细胞与DNA构建体产生转基因小鼠，并且它们在牛角蛋白5启动子的控制下表达整个串珠蛋白核心蛋白。通过电镜观察、免疫组化和RT-PCR方法研究串珠素和牙胚相关分子的表达情况，结果表明串珠素在Tg小鼠牙胚上皮组织中有较强的表达，其中包括釉质器官。形态学上，Tg磨牙的星状网状结构显示细胞间增宽， ...更多信息胚胎期（E13-E18），牙板较厚，形状不规则。在出生后第1天（P1）Tg小鼠，成釉器官明显缺乏细胞密度和较少的血管化。最后，Tg磨牙的冠形状变得钝端，与不完全结晶和分叉的牙根在下颌磨牙。TGF-β1和PKC-α mRNA在Tg牙胚中的表达水平在P1时显著升高。推测串珠素可能通过结合和释放生长因子来调控基质的空间排列，并作为营养物质在上皮内扩散转运的载体。在牙形成过程中，串珠素可能有助于形成高度水合的环境，以实现成釉器官中细胞的生长和分化。然而，串珠素的上皮内表达的时间表似乎是严格控制的，因为串珠素的持续过度表达干扰了正常的牙齿形态发生。少