Slater Bethany J, Kwan Matthew D, Gupta Deepak M, Lee Jacqueline K, Longaker Michael T
Stanford, Calif. From the Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine.
Plast Reconstr Surg. 2009 Feb;123(2):463-469. doi: 10.1097/PRS.0b013e3181954d21.
Craniosynostosis, the premature fusion of one or more cranial sutures, is a common developmental disorder resulting in morphologic and functional consequences. The rat model is useful for studying pathologic and normal suture fusion because the posterior frontal suture undergoes fusion but the remaining sutures remain patent. The authors investigated the influence of regional posterior frontal dura mater on the overlying suture morphology and fate.
In 8-day-old Sprague-Dawley rats, an 8-mm calvarial disk was excised without disrupting the underlying dura mater (n = 22) and flipped so that the previously ectocranial aspect was adjacent to the dura mater. The animals were humanely killed after 5, 7, 9, 11, and 28 days, and the posterior frontal sutures were analyzed histologically. A comparison was made to control animals in which the disk was excised and then placed back into its anatomical position (n = 5). Immunohistochemistry of the transforming growth factor (TGF)-beta isoforms was performed to investigate their differential, temporal, and spatial expression.
Posterior frontal suture fusion occurred on the side adjacent to the dura mater (previously patent ectocranial aspect) in an anterior-to-posterior direction, similar to that in the control group. There was specific expression of the TGF-beta isoforms in the dura mater and suture mesenchyme adjacent to the dura mater.
Regional dura mater plays an important role in suture morphology, and the posterior frontal-associated dura mater possesses potent, pro-osteogenic signals that influence the overlying suture fate. The differential expression pattern of TGF-beta signaling from the dura mater further supports the regional paracrine effect of the dura mater.
颅缝早闭是指一条或多条颅骨缝过早融合，是一种常见的发育障碍，会导致形态和功能方面的后果。大鼠模型对于研究病理性和正常的颅骨缝融合很有用，因为额后缝会发生融合，而其余颅骨缝仍保持开放。作者研究了额后硬脑膜区域对其上方颅骨缝形态和转归的影响。
在8日龄的斯普拉格-道利大鼠中，切除一个8毫米的颅骨盘，不破坏其下方的硬脑膜（n = 22），然后翻转，使先前的颅外表面与硬脑膜相邻。在5、7、9、11和28天后对动物实施安乐死，并对额后缝进行组织学分析。与切除颅骨盘后再放回其解剖位置的对照动物（n = 5）进行比较。对转化生长因子（TGF）-β亚型进行免疫组织化学分析，以研究它们的差异、时间和空间表达。
额后缝在与硬脑膜相邻的一侧（先前开放的颅外表面）从前向后发生融合，与对照组相似。TGF-β亚型在硬脑膜和与硬脑膜相邻的颅骨缝间充质中有特异性表达。
局部硬脑膜在颅骨缝形态中起重要作用，与额后相关的硬脑膜具有强大的促骨生成信号，可影响其上方颅骨缝的转归。来自硬脑膜的TGF-β信号的差异表达模式进一步支持了硬脑膜的局部旁分泌作用。
