Yamada Yurie, Ohazama Atsushi, Maeda Takeyasu, Seo Kenji
Center for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; Division of Oral Anatomy, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
Division of Oral Anatomy, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
Neurosci Lett. 2018 Apr 3;671:114-119. doi: 10.1016/j.neulet.2017.12.051. Epub 2018 Feb 8.
Activation of Shh signaling is known to be observed following injury of the peripheral nerves such as the sciatic nerve. However, the precise role of Shh signaling during peripheral nerve regeneration is not fully understood. The inferior alveolar nerve (IAN) is most commonly injured during oral surgery. Unlike the sciatic nerve, the IAN is isolated from other craniofacial tissues, as it resides in a long bony canal within the mandible. The IAN is thus an excellent experimental model for investigating peripheral nerve regeneration. In this study, the role of Shh signaling in peripheral nerve regeneration was investigated using the mouse IAN transection model. During regeneration, Shh signaling was activated within the entire distal region of the IAN and proximal stumps. Inhibition of Shh signaling by cyclopamine application at the transection site led to abnormal axon growth in random directions, a reduced number of macrophages, and an increase in myelin debris within the distal region. Shh signaling is thus involved in peripheral nerve regeneration via the regulation of myelin degradation.
已知在诸如坐骨神经等周围神经损伤后会观察到Shh信号通路的激活。然而，Shh信号通路在周围神经再生过程中的精确作用尚未完全明确。下牙槽神经（IAN）在口腔手术中最常受到损伤。与坐骨神经不同，IAN与其他颅面组织分离，因为它位于下颌骨内的一条长骨管中。因此，IAN是研究周围神经再生的理想实验模型。在本研究中，使用小鼠IAN横断模型研究了Shh信号通路在周围神经再生中的作用。在再生过程中，Shh信号通路在IAN的整个远端区域和近端残端内被激活。在横断部位应用环杷明抑制Shh信号通路会导致轴突向随机方向异常生长、巨噬细胞数量减少以及远端区域内髓鞘碎片增加。因此，Shh信号通路通过调节髓鞘降解参与周围神经再生。
