Dentinal defects in Hyp mice not caused by hypophosphatemia alone
Dentinal defects in Hyp mice not caused by hypophosphatemia alone
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DOI：
10.1016/j.archoralbio.2005.05.005
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发表时间：
2006-01-01
影响因子：
3
通讯作者：
Ooshima, T
中科院分区：
文献类型：
--
作者：
Ogawa, T;Onishi, T;Ooshima, T
Hyp小鼠是人类X-连锁低磷酸盐血症性佝偻病的小鼠同源物，并且由于与X染色体上的内肽酶（Phex）基因同源的磷酸盐调节基因的缺陷而在骨和牙本质中显示低矿化。以往认为Hyp小鼠的骨和牙本质缺损是由低磷酸盐血症引起的，但近年来的研究表明Hyp小鼠成骨细胞可能存在内在缺陷。此外，我们先前发现Hyp小鼠成牙本质细胞中骨钙素（OC）mRNA的高表达，并建议存在内在缺陷的可能性。在本研究中，我们评估的形态学特征和OC mRNA表达水平与正常phex基因和低浓度的血清磷的Nor小鼠的牙胚，并将它们与Hyp和野生型小鼠进行比较。Nor小鼠表现出低血清磷酸盐水平，然而，没有表现出特征性的特征，牙本质缺陷中看到的Hyp小鼠，如扩大predentin和OC mRNA的高表达。这些结果提示Hyp小鼠牙本质低矿化不依赖于血清磷酸盐水平，而是受成牙本质细胞内在缺陷的影响。(c)2005爱思唯尔有限公司保留所有权利。
The Hyp mouse is a murine homolog of human X-linked hypophosphatemic rickets and displays hypo-mineralization in bone and dentin due to a defect of the phosphate-regulating gene with homology to endopeptidase on the X chromosome (Phex) gene. It has tong been considered that the bone and dentin defects in Hyp mice are caused by hypophosphatemia atone, however, several recent studies have indicated the possibility that intrinsic defects are present in Hyp mice osteoblasts. Further, we previously found a hyper-expression of osteocatcin (OC) mRNA in Hyp mouse odontoblasts and suggested the possibility of the presence of intrinsic defects. In the present study, we evaluated morphological features and OC mRNA expression levels in tooth germs of Nor mice with a normal phex gene and a tow concentration of serum phosphate, and compared them to those in Hyp and wild-type mice. Nor mice exhibited low serum phosphate levels, however, did not show the characteristic features of dentin defects seen in Hyp mice, such as widened predentin and hyperexpression of OC mRNA. These results suggest that the hypo-mineralization of dentin in Hyp mice is not dependent on serum phosphate level, but rather is affected by intrinsic defects in odontoblasts. (c) 2005 Elsevier Ltd. All rights reserved.