Bone mineralization in an osteogenesis imperfecta mouse model studied by small-angle x-ray scattering
Bone mineralization in an osteogenesis imperfecta mouse model studied by small-angle x-ray scattering
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DOI：
10.1172/jci118428
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发表时间：
1996-01-15
影响因子：
15.9
通讯作者：
Landis, WJ
中科院分区：
文献类型：
--
作者：
Fratzl, P;Paris, O;Landis, WJ
我们研究了oim/oim小鼠皮质骨中矿物晶体的大小和取向，已知oim/oim小鼠仅产生α 1（I）胶原同源三聚体，并可作为人类骨生成的模型。长骨（股骨和胫骨）从年轻（5周龄）oim/oim小鼠和未受影响的杂合子同行进行了研究，小角X射线散射（SAXS），这是敏感的结构小于50 nm。矿物晶体进行了比较，在他们的厚度和他们的对齐相对于长骨轴。虽然电子显微镜断层扫描最近显示存在大的矿物质块（所有尺寸通常超过50纳米）的oim/oim小鼠的矿化肌腱，SAXS揭示了一个家庭的薄，可能针状，晶体在皮质骨。这些晶体的形状与以前在正常小鼠中观察到的相似，但相对于杂合子，它们在oim/oim小鼠中更薄且排列不那么整齐。此外，晶体厚度及其与骨轴的对齐在oim/oim骨中更易变化，两者之间具有密切的相关性（r = 0.94，P < 0.001）。在oim/oim小鼠的皮质中存在更小的晶体和更可变的排列，这可能导致它们的骨的脆性，类似于人类成骨细胞的脆性。
We have studied the size and orientation of mineral crystals in cortical bone of oim/oim mice, which are known to produce only alpha 1(I) collagen homotrimers and which may serve as a model for human osteogenesis imperfecta. Long bones (femur and tibia) from young (5 wk old) oim/oim mice and from unaffected heterozygous counterparts were investigated by small-angle x-ray scattering (SAXS), which is sensitive to structures smaller than 50 nm. Mineral crystals were compared in terms of their thickness and their alignment with respect to the long bone axis. While electron microscopic tomography has recently shown the existence of large mineral blocks (with all dimensions typically exceeding 50 nm) in mineralized tendons of oim/oim mice, SAXS revealed a family of thin, possibly needle-like, crystals in cortical bone. These crystals were similar in shape to those observed previously in normal mice, but they were thinner and less well aligned in oim/oim mice relative to heterozygotes. Moreover, the crystal thickness and their alignment with the bone axis were more variable in oim/oim bone, with a close correlation (r = 0.94, P < 0.001) between the two parameters. The presence of smaller crystals with more variable alignment in corticalis of oim/oim mice may contribute to the brittleness of their bone, similar to that of human osteogenesis imperfecta.