Patients lacking the major CNS myelin protein, proteolipid protein 1, develop length-dependent axonal degeneration in the absence of demyelination and inflammation
- PMID: 11872612
- DOI: 10.1093/brain/awf043
Patients lacking the major CNS myelin protein, proteolipid protein 1, develop length-dependent axonal degeneration in the absence of demyelination and inflammation
Abstract
Axonal degeneration contributes to clinical disability in the acquired demyelinating disease multiple sclerosis. Axonal degeneration occurs during acute attacks, associated with inflammation, and during the chronic progressive phase of the disease in which inflammation is not prominent. To explore the importance of interactions between oligodendrocytes and axons in the CNS, we analysed the brains of rodents and humans with a null mutation in the gene encoding the major CNS myelin protein, proteolipid protein (PLP1, previously PLP). Histological analyses of the CNS of Plp1 null mice and of autopsy material from patients with null PLP1 mutations were performed to evaluate axonal and myelin integrity. In vivo proton magnetic resonance spectroscopy (MRS) of PLP1 null patients was conducted to measure levels of N-acetyl aspartate (NAA), a marker of axonal integrity. Length-dependent axonal degeneration without demyelination was identified in the CNS of Plp1 null mice. Proton MRS of PLP1-deficient patients showed reduced NAA levels, consistent with axonal loss. Analysis of patients' brain tissue also demonstrated a length-dependent pattern of axonal loss without significant demyelination. Therefore, axonal degeneration occurs in humans as well as mice lacking the major myelin protein PLP1. This degeneration is length-dependent, similar to that found in the PNS of patients with the inherited demyelinating neuropathy, CMT1A, but is not associated with significant demyelination. Disruption of PLP1-mediated axonal--glial interactions thus probably causes this axonal degeneration. A similar mechanism may be responsible for axonal degeneration and clinical disability that occur in patients with multiple sclerosis.
Similar articles
-
Novel pathologic findings in patients with Pelizaeus-Merzbacher disease.Neurosci Lett. 2016 Aug 3;627:222-32. doi: 10.1016/j.neulet.2016.05.028. Epub 2016 May 17. Neurosci Lett. 2016. PMID: 27222925 Free PMC article.
-
Neural stem cells restore myelin in a demyelinating model of Pelizaeus-Merzbacher disease.Brain. 2020 May 1;143(5):1383-1399. doi: 10.1093/brain/awaa080. Brain. 2020. PMID: 32419025 Free PMC article.
-
Pelizaeus-Merzbacher disease: pathogenic mechanisms and insights into the roles of proteolipid protein 1 in the nervous system.J Neurol Sci. 2005 Feb 15;228(2):201-3. doi: 10.1016/j.jns.2004.10.010. Epub 2004 Dec 16. J Neurol Sci. 2005. PMID: 15694206 Review. No abstract available.
-
Neuronal loss in Pelizaeus-Merzbacher disease differs in various mutations of the proteolipid protein 1.Acta Neuropathol. 2009 Oct;118(4):531-9. doi: 10.1007/s00401-009-0562-8. Epub 2009 Jun 27. Acta Neuropathol. 2009. PMID: 19562355 Free PMC article.
-
Pelizaeus-Merzbacher disease: Genetic and cellular pathogenesis.Cell Mol Life Sci. 2007 Jan;64(1):50-65. doi: 10.1007/s00018-006-6182-8. Cell Mol Life Sci. 2007. PMID: 17115121 Free PMC article. Review.
Cited by
-
Heterogeneity in oligodendroglia: Is it relevant to mouse models and human disease?J Neurosci Res. 2016 Dec;94(12):1421-1433. doi: 10.1002/jnr.23900. Epub 2016 Aug 25. J Neurosci Res. 2016. PMID: 27557736 Free PMC article. Review.
-
Neuroprotection and repair in multiple sclerosis.Nat Rev Neurol. 2012 Nov 5;8(11):624-34. doi: 10.1038/nrneurol.2012.200. Epub 2012 Oct 2. Nat Rev Neurol. 2012. PMID: 23026979 Review.
-
Hereditary spastic paraplegia.Curr Neurol Neurosci Rep. 2006 Jan;6(1):65-76. doi: 10.1007/s11910-996-0011-1. Curr Neurol Neurosci Rep. 2006. PMID: 16469273 Review.
-
Mutation of Proteolipid Protein 1 Gene: From Severe Hypomyelinating Leukodystrophy to Inherited Spastic Paraplegia.Biomedicines. 2022 Jul 15;10(7):1709. doi: 10.3390/biomedicines10071709. Biomedicines. 2022. PMID: 35885014 Free PMC article. Review.
-
Mice with altered myelin proteolipid protein gene expression display cognitive deficits accompanied by abnormal neuron-glia interactions and decreased conduction velocities.J Neurosci. 2009 Jul 1;29(26):8363-71. doi: 10.1523/JNEUROSCI.3216-08.2009. J Neurosci. 2009. PMID: 19571127 Free PMC article.
Publication types
MeSH terms
Substances
LinkOut - more resources
Full Text Sources
Molecular Biology Databases
Research Materials