Mandibular deformities in parathyroid hormone-related protein (PTHrP) deficient mice: possible involvement of masseter muscle
Mandibular deformities in parathyroid hormone-related protein (PTHrP) deficient mice: possible involvement of masseter muscle
复制标题
甲状旁腺激素相关蛋白（PTHrP）缺陷小鼠的下颌畸形：可能涉及咬肌
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
V. Hammond
中科院分区：
文献类型：
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作者：
S. Shibata;N. Suda;K. Yamazaki;T. Kuroda;F. Beck;P. Senior;V. Hammond
以往使用甲状旁腺激素相关蛋白(PTHrP)缺失突变小鼠的研究表明，软骨内成骨存在严重异常，提示PTHrP影响软骨细胞的分化。在这项研究中，我们在新生的PTHrP缺陷小鼠中发现了一些通过膜内成骨形成的下颌畸形。下颌升支向下弯曲，下颌体部可见一突出的骨脊，咬肌深层呈带状附着于其上。透射电子显微镜研究显示，活跃的骨形成是沿着咬肌的肌腱纤维进行的。三维重建模型检查显示，下颌升支在肌附着处发生弯曲，并向肌纤维方向移动。肌球蛋白ATPase染色的肌肉纤维类型分析显示，新生PTHrP缺陷小鼠的咬肌含有大量的2B型纤维，表明该肌肉过早成熟。基于这些发现，我们推测咬肌的过早成熟可能是由于张力的增加，加速了骨脊的形成和随后下颌支的弯曲。这些结果进一步表明，PTHrP参与了正常动物肌肉发育的调节。
Previous studies using parathyroid hormone-related protein (PTHrP) null mutant mice have indicated severe abnormalities in the endochondral ossification, suggesting that PTHrP affects chondrocyte differentiation. In this study, we found in newborn PTHrP-deficient mice some deformities in the mandible that is formed via intramembranous ossification. The mandibular ramus was bent downwards and a prominent bone crest to which the deep layer of masseter muscle was tendinously attached was observed in the mandibular body. Transmission electron microscopic studies showed that active bone formation was progressing along the tendon fibers of the masseter muscle. The examination of 3-D reconstruction models indicated that the mandibular ramus was bent at the site of muscle attachment, which was shifted in the direction of the muscle fibers. Muscle fiber type analysis using myosin ATPase staining showed that the masseter muscle in the newborn PTHrP-deficient mice contained numerous type 2B fibers, demonstrating premature maturation of this muscle. Based on these findings, we speculated that premature maturation of the masseter muscle leads, probably due to increased tensile forces, to accelerated bone crest formation and subsequent bending of the mandibular ramus. These results further suggest that PTHrP is involved in the regulation of muscle development in normal animals.
影响因子：
10.5
作者：
KARAPLIS, AC;LUZ, A;MULLIGAN, RC
通讯作者：
MULLIGAN, RC