Search results for "Myelin"
showing 10 items of 329 documents
Myelin: Methods for Purification and Proteome Analysis
2019
Molecular characterization of myelin is a prerequisite for understanding the normal structure of the axon/myelin-unit in the healthy nervous system and abnormalities in myelin-related disorders. However, reliable molecular profiles necessitate very pure myelin membranes, in particular when considering the power of highly sensitive "omics"-data acquisition methods. Here, we recapitulate the history and recent applications of myelin purification. We then provide our laboratory protocols for the biochemical isolation of a highly pure myelin-enriched fraction from mouse brains and for its proteomic analysis. We also supply methodological modifications when investigating posttranslational modifi…
Dual role of the RNA helicase DDX5 in post-transcriptional regulation of Myelin Basic Protein in oligodendrocytes
2017
In the central nervous system, oligodendroglial expression of Myelin Basic Protein (MBP) is crucial for the assembly and structure of the myelin sheath. MBP synthesis is tightly regulated in space and time, particularly on the post-transcriptional level. We have identified the DEAD-box RNA helicase DDX5 (alias p68) in a complex with Mbp mRNA in oligodendroglial cells. Expression of DDX5 is highest in progenitor cells and immature oligodendrocytes, where it localizes to heterogeneous populations of cytoplasmic ribonucleoprotein (RNP) complexes associated with Mbp mRNA in the cell body and processes. Manipulation of DDX5 protein amounts inversely affects levels of MBP protein. We present evid…
Inflammatory demyelination induces ependymal modifications concomitant to activation of adult (SVZ) stem cell proliferation
2017
Ependymal cells (E1/E2) and ciliated B1cells confer a unique pinwheel architecture to the ventricular surface of the subventricular zone (SVZ), and their cilia act as sensors to ventricular changes during development and aging. While several studies showed that forebrain demyelination reactivates the SVZ triggering proliferation, ectopic migration, and oligodendrogenesis for myelin repair, the potential role of ciliated cells in this process was not investigated. Using conventional and lateral wall whole mount preparation immunohistochemistry in addition to electron microscopy in a forebrain-targeted model of experimental autoimmune encephalomyelitis (tEAE), we show an early decrease in num…
Role of the epigenetic factor Sirt7 in neuroinflammation and neurogenesis.
2017
Epigenetic regulators are increasingly recognized as relevant modulators in the immune and nervous system. The class of sirtuins consists of NAD+-dependent histone deacetylases that regulate transcription. Sirtuin family member Sirt1 has already been shown to influence the disease course in an animal model of autoimmune neuroinflammation (experimental autoimmune encephalomyelitis (EAE). A role of Sirt7, a related epigenetic regulator, on immune system regulation has been proposed before, as these mice are more susceptible to develop inflammatory cardiomyopathy. Sirt7-/- animals showed no differences in clinical score compared to wild-type littermates after EAE induction with myelin oligoden…
Consensus recommendation for a diagnostic guideline for acid sphingomyelinase deficiency
2017
Disclaimer: This diagnostic guideline is intended as an educational resource and represents the opinions of the authors, and is not representative of recommendations or policy of the American College of Medical Genetics and Genomics (ACMG). The information should be considered a consensus based on expert opinion, as more comprehensive levels of evidence were not available in the literature in all cases. Background: Acid sphingomyelinase deficiency (ASMD) is a rare, progressive, and often fatal lysosomal storage disease. The underlying metabolic defect is deficiency of the enzyme acid sphingomyelinase that results in progressive accumulation of sphingomyelin in target tissues. ASMD manifests…
Oligodendrocytes control potassium accumulation in white matter and seizure susceptibility
2018
Oligodendrocytes Control Potassium Accumulation in White Matter and Seizure Susceptibility.Larson VA, Mironova Y, Vanderpool KG, Waisman A, Rash JE, Agarwal A, Bergles DE. Elife. 2018 Mar 29;7. pii: e34829. doi: 10.7554/eLife.34829.The inwardly rectifying K+ channel Kir4.1 is broadly expressed by central nervous system glia and deficits in Kir4.1 lead to seizures and myelin vacuolization. However, the role of oligodendrocyte Kir4.1 channels in controlling myelination and K+ clearance in white matter has not been defined. Here, we show that selective deletion of Kir4.1 from oligodendrocyte progenitors or mature oligodendrocytes did not impair their development or disrupt the structure of mye…
Diversity in the Oligodendrocyte Lineage: Current Evidence
2019
Summary Oligodendrocyte progenitor cells (OPCs), which differentiate into myelinating oligodendrocytes during CNS development, are the main proliferative cells in the adult brain. OPCs are conventionally considered a homogeneous population, particularly with respect to their electrophysiological properties, but this has been debated. We show, by using single-cell electrophysiological recordings, that OPCs start out as a homogeneous population but become functionally heterogeneous, varying both within and between brain regions and with age. These electrophysiological changes in OPCs correlate with the differentiation potential of OPCs; thus, they may underlie the differentiational difference…
Biallelic variants in LARS2 and KARS cause deafness and (ovario)leukodystrophy
2019
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Transcriptome-Wide Analysis Identifies Novel Associations With Blood Pressure.
2017
Hypertension represents a major cardiovascular risk factor. The pathophysiology of increased blood pressure (BP) is not yet completely understood. Transcriptome profiling offers possibilities to uncover genetics effects on BP. Based on 2 populations including 2549 individuals, a meta-analyses of monocytic transcriptome-wide profiles were performed to identify transcripts associated with BP. Replication was performed in 2 independent studies of whole-blood transcriptome data including 1990 individuals. For identified candidate genes, a direct link between long-term changes in BP and gene expression over time and by treatment with BP-lowering therapy was assessed. The predictive value of pro…
General control non-derepressible 2 (GCN2) in T cells controls disease progression of autoimmune neuroinflammation.
2016
Relapsing-remitting multiple sclerosis (MS)(2) is characterized by phases of acute neuroinflammation followed by spontaneous remission. Termination of inflammation is accompanied by an influx of regulatory T cells (Tregs).(3) The molecular mechanisms responsible for directing Tregs into the inflamed CNS tissue, however, are incompletely understood. In an MS mouse model we show that the stress kinase general control non-derepressible 2 (GCN2),(4) expressed in T cells, contributes to the resolution of autoimmune neuroinflammation. Failure to recover from acute inflammation was associated with reduced frequencies of CNS-infiltrating Tregs. GCN2 deficient Tregs displayed impaired migration to a…