Fruttiger M, Montag D, Schachner M, Martini R
Department of Neurobiology, Swiss Federal Institute of Technology, Hönggerberg, Zurich.
Eur J Neurosci. 1995 Mar 1;7(3):511-5. doi: 10.1111/j.1460-9568.1995.tb00347.x.
It has recently been shown that mice deficient in the gene for myelin-associated glycoprotein develop normal myelin sheaths in the peripheral nervous system. Here we report that in mutant mice older than 8 months the maintenance of axon-myelin units is disturbed, resulting in both axon and myelin degeneration. Morphological features include those typically seen in human peripheral neuropathies, where demyelination-induced Schwann cell proliferation and remyelination lead to the formation of so-called onion bulbs. Expression of tenascin-C, a molecule indicative of peripheral nerve degeneration, was up-regulated by axon-deprived Schwann cells and regenerating axons were occasionally seen. Myelin-associated glycoprotein thus appears to play a crucial role in the long-term maintenance of the integrity of both myelin and axons.
最近研究表明，髓鞘相关糖蛋白基因缺陷的小鼠在外周神经系统中能形成正常的髓鞘。在此我们报告，在8个月以上的突变小鼠中，轴突-髓鞘单元的维持受到干扰，导致轴突和髓鞘均发生退化。形态学特征包括人类外周神经病变中常见的特征，即脱髓鞘诱导施万细胞增殖和再髓鞘化导致所谓洋葱球的形成。轴突剥夺的施万细胞上调了腱生蛋白-C的表达，腱生蛋白-C是一种指示外周神经退化的分子，偶尔可见再生轴突。因此，髓鞘相关糖蛋白似乎在髓鞘和轴突完整性的长期维持中起关键作用。
