Dilated capillaries, disorganized collagen fibers and differential gene expression in periodontal ligaments of hypomorphic fibrillin-1 mice
Dilated capillaries, disorganized collagen fibers and differential gene expression in periodontal ligaments of hypomorphic fibrillin-1 mice
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DOI：
10.1007/s00441-010-1021-5
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发表时间：
2010-09-01
影响因子：
3.6
通讯作者：
Moriyama, Keiji
中科院分区：
文献类型：
--
作者：
Ganburged, Ganjargal;Suda, Naoto;Moriyama, Keiji
牙周韧带是覆盖牙根面的牙骨质与牙槽骨之间的软结缔组织。PDL由胶原和弹性系统纤维、血管、神经和各种类型的细胞组成。弹性系统纤维一般由弹性蛋白和微原纤维组成，但PDL主要由后者组成。与胶原纤维支持牙齿的功能相比，弹性系统纤维在牙周膜中的作用知之甚少。为了阐明它们的作用，我们研究了低表达β-内酰胺酶-1（mgR小鼠）的PDL，β-内酰胺酶-1是主要的微纤维蛋白之一。纯合子mgR小鼠的PDL显示出野生型（WT）小鼠弹性系统纤维的四分之一。在WT、纯合子和杂合子mgR小鼠中注意到弹性系统纤维和毛细血管之间的密切关联。有趣的是，与WT小鼠相比，纯合子小鼠PDL中的毛细血管扩张或扩大。具有三种基因型的小鼠的PDL细胞中表达了相当水平的I型胶原，其是PDL中的主要胶原。然而，在纯合子小鼠中观察到具有较薄外观的多取向胶原纤维束，而在WT小鼠中观察到组织良好的胶原纤维束。此外，骨膜蛋白表达显著降低，已知其调节胶原纤维形成和交联。这些观察结果表明，微纤维蛋白，casein-1，是不可缺少的正常组织结构和基因表达的PDL。
The periodontal ligaments (PDLs) are soft connective tissue between the cementum covering the tooth root surface and alveolar bone. PDLs are composed of collagen and elastic system fibers, blood vessels, nerves, and various types of cells. Elastic system fibers are generally formed by elastin and microfibrils, but PDLs are mainly composed of the latter. Compared with the well-known function of collagen fibers to support teeth, little is known about the role of elastic system fibers in PDLs. To clarify their role, we examined PDLs of mice underexpressing fibrillin-1 (mgR mice), which is one of the major microfibrillar proteins. The PDLs of homozygous mgR mice showed one-quarter of the elastic system fibers of wild-type (WT) mice. A close association between the elastic system fibers and the capillaries was noted in WT, homozygous and heterozygous mgR mice. Interestingly, capillaries in PDLs of homozygous mice were dilated or enlarged compared with those of WT mice. A comparable level of type I collagen, which is the major collagen in PDLs, was expressed in PDL-cells of mice with three genotypes. However, multi-oriented collagen fiber bundles with a thinner appearance were noted in homozygous mice, whereas well-organized collagen fiber bundles were seen in WT mice. Moreover, there was a marked decrease in periostin expression, which is known to regulate the fibrillogenesis and crosslinking of collagen. These observations suggest that the microfibrillar protein, fibrillin-1, is indispensable for normal tissue architecture and gene expression of PDLs.