Insulin-like growth factor-I promotes myelination of peripheral sensory axons.
Insulin-like growth factor-I promotes myelination of peripheral sensory axons.
复制标题
胰岛素样生长因子-I 促进外周感觉轴突的髓鞘形成。
DOI：
10.1093/jnen/59.7.575
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发表时间：
2000
影响因子：
3.2
通讯作者：
Golovoy,D
中科院分区：
文献类型：
--
作者：
Russell,JW;Cheng,HL;Golovoy,D
胰岛素样生长因子-I (IGF-I) 在体内或在其他允许因素存在的情况下可以促进中枢神经系统的髓鞘形成。在当前的研究中，我们研究了 IGF-I 在周围神经髓鞘形成中的作用。在大鼠背根神经节 (DRG) 和雪旺细胞 (SC) 在无血清和无胰岛素的确定培养基中共培养时，IGF-I 诱导髓磷脂蛋白（如 P0）剂量依赖性上调，对应于最大 SC 鞘。此外，IGF-I 对于促进 DRG 感觉轴突的剂量依赖性长期髓鞘化至关重要。在缺乏 IGF-I 的情况下，轴突和 SC 可以存活，但不能形成髓鞘。在存在 10 nM IGF-I 的情况下，59% 的轴突在 21 天时形成髓鞘，而在不存在 IGF-I 的情况下，则无法发生髓鞘形成。添加 IGF-I 后 48 小时出现最大 SC 鞘。如果在 48 小时撤回 IGF-I，SC 的轴突分离仍然存在，然而，大多数轴突和 SC 不表现出一对一的关系，并且观察到很少的髓鞘形成。 IGF-I 在髓鞘形成中很重要，不仅对于轴突的初始 SC 鞘和髓磷脂蛋白的上调至关重要，而且对于持续髓鞘形成也至关重要。此外，IGF-I 相关的轴突大小并不是髓鞘形成的唯一决定因素。
Insulin-like growth factor-I (IGF-I) in vivo or in the presence of other permissive factors can promote myelination in the central nervous system. In the current study, we examine the role of IGF-I in the myelination of peripheral nerves. In rat cocultures of dorsal root ganglia (DRG) and Schwann cells (SC) grown in serum- and insulin-free defined medium, IGF-I induces a dose dependent upregulation in myelin proteins such as P0, corresponding to maximal SC ensheathment. Furthermore, IGF-I is essential in promoting a dose-dependent, long-term myelination of DRG sensory axons. In the absence of IGF-I, axons and SC survive, but fail to myelinate. In the presence of 10 nM IGF-I, 59% of axons are myelinated at 21 days, whereas in the absence of IGF-I myelination fails to occur. Maximum SC ensheathment occurs 48 hours after addition of IGF-I. If IGF-I is withdrawn at 48 hours, axon segregation by SC persists, however, most axons and SC do not exhibit a one-to-one relationship and little myelination is observed. IGF-I is important in myelination and is critical not only for initial SC ensheathment of the axon and upregulation of myelin proteins, but also for sustained myelination. Furthermore, IGF-I associated axonal size is not the sole determinant for myelination.