Biomineralization and adaptive plasticity of the temporomandibular joint in myostatin knockout mice
Biomineralization and adaptive plasticity of the temporomandibular joint in myostatin knockout mice
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DOI：
10.1016/j.archoralbio.2005.05.008
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发表时间：
2006-01-01
影响因子：
3
通讯作者：
Ravosa, MJ
中科院分区：
文献类型：
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作者：
Nicholson, EK;Stock, SR;Ravosa, MJ
服用肌肉抑制素(GDF-8)的小鼠，骨骼肌生长的负面调节因子，显示出与正常小鼠相比，肌肉质量显著增加。我们比较了野生型和肌肉抑制素缺乏的小鼠，以评估由于下颌内收肌活动增加和咬合力增加而导致的咀嚼负荷增加对下颌突形态的出生后影响。使用微型计算机断层扫描(MicroCT)来提供内部髁状突形态的细节，并对三个髁状突区域的骨密度进行量化。生物矿化水平以及下颌骨外部尺寸被用来表征切片内、关节内、组内和组间的差异。在myostatin基因敲除的小鼠中，下颌骨和下颌突的尺寸与正常小鼠相似。基因敲除的小鼠表现出更多的生物矿化，在关节突下软骨下骨的外表面和沿髁突颈，最明显的是在髁突颈的颊侧。在基因敲除的小鼠中，内侧面的颊侧面生物矿化显著较少，无论是对于汇集的数据，还是对于后、前髁状突切片而言。正常小鼠的软骨下骨表面是对称的，而基因敲除小鼠的软骨下骨表面是不对称的，颊侧比舌侧的表面更低，凸度更小。这似乎与与正常小鼠相比下颌骨咀嚼应力增加的个体发育效应有关。正常小鼠和肌肉生长抑素基因敲除小鼠之间在生物矿化方面的显著差异，以及某些外部尺寸的显著差异，突显了相对于改变或过度机械蛙的矿化组织外部和内部形态信息的需要。(C)2005年由爱思唯尔有限公司出版。
Mice tacking myostatin (GDF-8), a negative regulator of skeletal muscle growth, show a significant increase in muscle mass versus normal mice. We compared wild-type and myostatin deficient mice to assess the postnatal effect of elevated masticatory loads due to increased jaw-adductor muscle activity and greater bite forces on mandibular condyle morphology. Microcomputed tomography (microCT) was used to provide details of internal condylar morphology and quantify bone density in three condylar regions. Biomineralization levels, as well as external mandibular dimensions, were used to characterize within-slice, within-joint, within-group and between-group variation.Dimensions of the mandible and mandibular condyle were similar between the myostatin knockout and normal mice. Knockout mice exhibited significantly more biomineratization on the outer surface of the condylar subchondral bone and along the condylar neck, most notably on the buccal side of the condylar neck. The buccal side of the inner aspect of the condyle was significantly less biomineralized in knockout mice, both for the pooled data and for the posterior and anterior condylar slices. Whilst normal mice had symmetric subchondral bone surfaces, those of knockout mice were asymmetric, with a lower, less convex surface on the buccal side versus the lingual side. This appears related to the ontogenetic effects of increased masticatory stress in the mandibles of knockout mice as compared to normal mice.Significant differences in biomineralization between normal and myostatin knockout mice, coupled with the tack of significant differences in certain external dimensions, underscores a need for information on the external and internal morphology of mineralized tissues vis-A-vis altered or excessive mechanical toads. (c) 2005 Published by Elsevier Ltd.