Collagen from the osteogenesis imperfecta mouse model (oim) shows reduced resistance against tensile stress
Collagen from the osteogenesis imperfecta mouse model (oim) shows reduced resistance against tensile stress
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DOI：
10.1172/jci119519
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发表时间：
1997-07-01
影响因子：
15.9
通讯作者：
Fratzl, P
中科院分区：
文献类型：
--
作者：
Misof, K;Landis, WJ;Fratzl, P
成骨不全(OI)是一种可归因于I型胶原大量可能突变的疾病，该病的临床特征部分是高度脆性的骨，其原因尚不清楚。最近，一种被命名为成骨不全鼠(OIM)的小鼠模型具有明确的基因突变，研究发现OI中含有与胶原的排列和大小不同的矿物晶体，这些观察结果与人类OI中报道的一致，并且不寻常的晶体排列和大小无疑导致OI骨的力学性能降低，虽然已经对这种矿物进行了研究，但关于OIM胶原的拉伸性能尚无相关信息。在这项研究中，我们检测了纯合(OIM/OIM)、杂合(+/OIM)和对照(+/+)小鼠肌腱胶原在拉伸下的力学性能。在自然潮湿的条件下，OIM/OIM胶原的极限应力和应变仅为对照小鼠的一半左右，假设预应变的胶原分子承担了正常骨骼中的大部分拉伸载荷，而矿物质提供了刚性和压缩稳定性，报道的结果表明，小鼠模型中OI骨的脆性可能与胶原的极限拉伸应变显著降低有关。
Osteogenesis imperfecta (OI) is a disease attributable to any of a large number of possible mutations of type I collagen, The disease is clinically characterized in part by highly brittle bone, the cause of this feature being unknown. Recently a mouse model of OI, designated as osteogenesis imperfecta murine (oim) and having a well defined genetic mutation, has been studied and found to contain mineral crystals different in their alignment with respect to collagen and in their size, These observations are consistent with those reported in human OI and the unusual crystal alignment and size undoubtedly contribute to the reduced mechanical properties of OI bone, While the mineral has been investigated, no information is available on the tensile properties of oim collagen. In this study, the mechanical properties of tendon collagen under tension have been examined for homozygous (oim/oim), heterozygous (+/oim), and control (+/+) mice under native wet conditions, The ultimate stress and strain found for oim/oim collagen were only about half the values for control mice, Assuming that prestrained collagen molecules carry most of the tensile load in normal bone while the mineral confers rigidity and compression stability, the reported results suggest that the brittleness of OI bone in the mouse model may be related to a dramatic reduction of the ultimate tensile strain of the collagen.