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Research of the physiological functions of membrane-type matrix metalloproteinases

膜型基质金属蛋白酶的生理功能研究

基本信息

批准号：
13470050
负责人：
SEIKI Motoharu
金额：
$ 10.05万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

In our murine strain deficient in MT1-MMP gene expression, the bone morphogenesis was severely impaired, consistent with the past reports. Next question would be an address to know which cell lineages in bone tissue are responsible to work with expressing MT1-MMP during the bone morphogenesis under the physiologic state. To see if a recovering of the MT1-MMP limitedly in bone tissue helps to revart the phenotype, a conditional transgenic strain is under construction based on the knock-out mice, in which expression of MT1-MMP is recovered restrictedly in osteoblasts. On the other hand, MT1-MMP plays a important role in angiogenesis around the ossification center during the second ossification. In order to understand the role more profoundly, three-dimensional culture of muscle chunks in type-I collagen has been conducted. Angiogenesis through the collagen was observed during the culturing period. The angiogenesis was severely impaired with the mucle chunk of the MT1-MMP deficient strain … More compared to the wild type or the hetero-zygote.MT1-MMP in the new vessels was predominantly expressed in endothelial cells. Questions remains how MT1-MMP plays a role in angiogenesis, why other proteinases can not compensate the functions sufficiently, or whether the impairment in second ossification in MT1-MMP deficient mice is induced predominantly by the poor angiogenesis around the bone. The conditional transgenic mice could provide us with some hints to ask for the queries.MT5-MMP has been found to expressed at neural cells such in cerebrum, cerebellum, and hypocampus. However, no distinct abnormality has been detected in a strain deficient in MT5-MMP gene. Based on the specificity in MT5-MMP expression, a neurite extension assay was performed with the murine neural cells derived from dorsal route ganglia, demonstrated that the protrusion of the neurite was facilitated on laminin, and inhibited on heparin binding proteoglycan. Adding a soluble MT5-MMP purified, The latter inhibition has released with a degradation of the substrate.Immunohistochemically, endogenous MT5-MMP was detected predominantly at the growth cone.MT4-MMP has been shown to be expressed such at a cortex in the frontal lobe of brain, hypocampus, cerebellum, nephron, smooth muscle cells in the vessels, heart, and red pulp in spleen. Histologically, no gloss abnormality was found in a strain- deficient in MT4-MMP gene. Several functional analyzes should be performed next to know how MT4-MMP plays roles in murine tissue. Less

在我们的MT1-MMP基因表达缺陷的小鼠中，骨形态发生严重受损，这与过去的报道一致。下一个问题将是了解在生理状态下的骨形态发生过程中，骨组织中哪些细胞系负责表达MT1-MMPs。为了观察MT1-MMPs在骨组织中的有限恢复是否有助于改变表型，正在构建一个基于基因敲除小鼠的条件转基因株，其中MT1-MMPs在成骨细胞中的表达受到限制。另一方面，在二次成骨过程中，MT1-MMPs在成骨中心周围的血管生成中起重要作用。为了更深入地了解这一作用，我们对肌块进行了I型胶原的三维培养。在培养过程中观察到通过胶原的血管生成。MT1-MMP1缺陷株…的粘液块严重损害血管生成与野生型或杂合子相比，新生血管中的MT1-MMP主要表达于内皮细胞。问题仍然是MT1-MMPs如何在血管生成中发挥作用，为什么其他蛋白酶不能充分补偿这一功能，或者MT1-MMPs缺陷小鼠的二次成骨障碍是否主要是由于骨周围血管生成不足所致。条件转基因小鼠可以为我们的提问提供一些线索。MT5-MMPs已被发现在大脑、小脑和下丘脑等神经细胞中表达。然而，在MT5-MMP基因缺陷株中未检测到明显的异常。根据MT5-MMP表达的特异性，用小鼠背路神经节来源的神经细胞进行了轴突延伸实验，结果表明，层粘连蛋白促进了突起的突起，而肝素结合蛋白多糖则抑制了突起的突起。免疫组织化学显示，内源性MT5-MMP主要在生长锥体中检测到，MT4-MMP在大脑额叶皮质、下丘脑、小脑、肾单位、血管中的平滑肌细胞、心脏和脾中的红髓中均有表达。在组织学上，未发现MT4-MMP1基因缺陷株的光泽异常。接下来应该进行几项功能分析，以了解MT4-MMPs如何在小鼠组织中发挥作用。较少