Insulin-Like Growth Factor-I Promotes Myelination of Peripheral Sensory Axons
| Autor: | Hsin-Lin Cheng, David Golovoy, James W. Russell |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Nervous system
medicine.medical_treatment Central nervous system Schwann cell Biology Nerve Fibers Myelinated Pathology and Forensic Medicine Rats Sprague-Dawley Cellular and Molecular Neuroscience Insulin-like growth factor Myelin Fetus Downregulation and upregulation Ganglia Spinal medicine Animals Neurons Afferent Insulin-Like Growth Factor I Axon Cells Cultured Myelin Sheath Growth factor General Medicine Rats Cell biology Microscopy Electron medicine.anatomical_structure nervous system Neurology Schwann Cells Neurology (clinical) Myelin P0 Protein Neuroscience |
| Zdroj: | Journal of Neuropathology & Experimental Neurology. 59:575-584 |
| ISSN: | 1554-6578 0022-3069 |
| DOI: | 10.1093/jnen/59.7.575 |
| Popis: | 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 P 11 , 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 Maximum SC ensheathment occurs 48 hours after addition of IGF-I. If IGF-I is withdrawn at 48 hours, axon segregation by SC persists, however, most axons and SC do not exhibit a one-to-one relationship and little myelination is observed.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. |
| Databáze: | OpenAIRE |
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