Delayed tooth eruption in membrane type-1 matrix metalloproteinase deficient mice
Delayed tooth eruption in membrane type-1 matrix metalloproteinase deficient mice
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DOI：
10.1080/03008200390181816
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发表时间：
2003-01-01
影响因子：
2.9
通讯作者：
Tryggvason, K
中科院分区：
文献类型：
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作者：
Bartlett, JD;Zhou, ZJ;Tryggvason, K
膜I型基质金属蛋白酶（MT 1-MMP）在骨骼和牙齿等矿化组织中高度表达。MT 1-MMP（-/-）缺陷的小鼠在骨骼发育中表现出严重的缺陷，包括侏儒症、骨质减少和颅面畸形。这些小鼠在约3周龄时死亡。由于MT 1-MMP表达的成釉细胞的成釉器官和牙乳头的成牙本质细胞，我们问，如果发育中的牙齿受到不利影响，在敲除动物。MT 1-MMP -/-小鼠和对照组的磨牙在出生后4、18-20和25天通过组织学、X射线和SEM分析进行检查。在发育的第4天，来自-/-小鼠的磨牙在组织学上表现正常。在发育的18-20天，-/-小鼠的第一磨牙具有明显正常的牙冠，具有正常的牙本质和釉质;然而，牙根被截断，牙齿尚未萌出。与-/-小鼠相反，18-20天对照组动物的第一磨牙已经萌出。扫描电子显微镜分析的一/-第一磨牙和切牙揭示了一个正常的釉质棱镜模式。然而，X射线分析表明，牙齿萌出延迟了约5天，并且在敲除动物中牙根异常短。由于MT 1-MMP-缺陷小鼠已被证明显示骨吸收的普遍增加，这些数据表明，牙根复合体周围的骨生长效率低下导致牙齿萌出延迟。
Membrane-type I matrix metalloproteinase (MT1-MMP) is expressed highly in mineralizing tissues including bones and teeth. Mice deficient in MT1-MMP (-/-) display severe defects in skeletal development including dwarfism, osteopenia, and craniofacial abnormalities. Death occurs in these mice by about 3 weeks of age. Since MT1-MMP is expressed by the ameloblasts of the enamel organ and by the odontoblasts of the dental papilla, we asked if the developing teeth were adversely affected in the knockout animals. Molars from MT1-MMP -/- mice and controls were examined by histological, X-ray, and SEM analysis at 4, 18-20, and 25 days of postnatal development. At 4 days of development the molars from the -/- mice appeared histologically normal. At 18-20 days of development, the first molars of the -/- mice had apparently normal tooth crowns with normal dentin and enamel; however, the roots were truncated and the teeth had not yet erupted. In contrast to the -/- mice, the first molars of the 18-20-day control animals had erupted. SEM analysis of a -/- first molar and incisor revealed a normal enamel prism pattern. However, X-ray analysis demonstrated that tooth eruption was delayed by approximately 5 days and that the tooth roots were abnormally short in the knockout animals. Since MT1-MMP-deficient mice have been demonstrated to display a generalized increase in bone resorption, these data suggest that inefficient growth of bone surrounding the tooth root complex causes a delay in tooth eruption.