Search results for "Schwann cell"
showing 10 items of 27 documents
Functions of histone modifications and histone modifiers in Schwann cells.
2019
Schwann cells (SCs) are the main glial cells present in the peripheral nervous system (PNS). Their primary functions are to insulate peripheral axons to protect them from the environment and to enable fast conduction of electric signals along big caliber axons by enwrapping them in a thick myelin sheath rich in lipids. In addition, SCs have the peculiar ability to foster axonal regrowth after a lesion by demyelinating and converting into repair cells that secrete neurotrophic factors and guide axons back to their former target to finally remyelinate regenerated axons. The different steps of SC development and their role in the maintenance of PNS integrity and regeneration after lesion are c…
Neurofibromatosis type 2 tumor suppressor protein is expressed in oligodendrocytes and regulates cell proliferation and process formation.
2017
The neurofibromatosis type 2 (NF2) tumor suppressor protein Merlin functions as a negative regulator of cell growth and actin dynamics in different cell types amongst which Schwann cells have been extensively studied. In contrast, the presence and the role of Merlin in oligodendrocytes, the myelin forming cells within the CNS, have not been elucidated. In this work, we demonstrate that Merlin immunoreactivity was broadly distributed in the white matter throughout the central nervous system. Following Merlin expression during development in the cerebellum, Merlin could be detected in the cerebellar white matter tract at early postnatal stages as shown by its co-localization with Olig2-positi…
Irreversible changes occurring in long-term denervated Schwann cells affect delayed nerve repair.
2017
OBJECTIVEMultiple factors may affect functional recovery after peripheral nerve injury, among them the lesion site and the interval between the injury and the surgical repair. When the nerve segment distal to the lesion site undergoes chronic degeneration, the ensuing regeneration (when allowed) is often poor. The aims of the current study were as follows: 1) to examine the expression changes of the neuregulin 1/ErbB system during long-term nerve degeneration; and 2) to investigate whether a chronically denervated distal nerve stump can sustain nerve regeneration of freshly axotomized axons.METHODSThis study used a rat surgical model of delayed nerve repair consisting of a cross suture betw…
Sox8 and Sox10 jointly maintain myelin gene expression in oligodendrocytes
2017
In Schwann cells of the vertebrate peripheral nervous system, induction of myelination and myelin maintenance both depend on the HMG-domain-containing transcription factor Sox10. In oligodendrocytes of the central nervous system, Sox10 is also essential for the induction of myelination. Its role in late phases of myelination and myelin maintenance has not been studied so far. Here, we show that these processes are largely unaffected in mice that lack Sox10 in mature oligodendrocytes. As Sox10 is co-expressed with the related Sox8, we also analyzed oligodendrocytes and myelination in Sox8-deficient mice. Again, we could not detect any major abnormalities. Expression of many myelin genes was …
A predominantly glial origin of axonal ribosomes after nerve injury
2017
Axonal mRNA transport and local protein synthesis are crucial for peripheral axon regeneration. To date, it remains unclear how ribosomes localize to axons. They may be co-transported with mRNAs or, as suggested by recent studies, transferred from Schwann cells (SC). Here, we generated transgenic "RiboTracker" mice expressing tdTomato-tagged ribosomal protein L4 in specific cell types when crossed with Cre lines. Two neuronal RiboTracker-Cre lines displayed extremely low levels of axonal L4-tdTomato-positive ribosomes. In contrast, two glial RiboTracker-Cre lines revealed tagged ribosomes in sciatic nerve (SN) axons with increasing amounts after injury. Furthermore, non-RiboTracker dorsal r…
11q Deletion or ALK Activity Curbs DLG2 Expression to Maintain an Undifferentiated State in Neuroblastoma
2020
High-risk 11q deleted neuroblastomas typically display undifferentiated/poorly differentiated morphology. Neuroblastoma is thought to develop from Schwann cell precursors and undifferentiated neural crest (NC) derived cells. It is therefore vital to understand mechanisms involved in the block of differentiation. We identify an important role for oncogenic ALK-ERK1/2-SP1 signaling in maintenance of undifferentiated NC-derived progenitors via repression of DLG2, a tumor suppressor in neuroblastoma. DLG2 is expressed in the ‘bridge signature’ that represents the transcriptional transition state when neural crest cells or Schwann Cell Precursors become chromaffin cells of the adrenal gland. We …
Granular cell tumor: report of 8 intraoral cases.
2006
El Tumor de células granulares es una neoplasia de origen controvertido que puede aparecer en múltiples localizaciones corporales, incluyendo la región orofacial. El comportamiento de este infrecuente tumor es benigno en la mayor parte de los casos, aunque en ocasiones puede presentar agresividad local e incluso malignidad con afectación a distancia. Su etiología es actualmente solo parcialmente conocida y ha generado controversia desde sus primeras descripciones teorizando sobre un origen muscular, conectivo, etc o neural. En este trabajo se presentan 8 casos clínicos con localización intraoral, correspondientes a 5 mujeres y 3 hombres, con una edad media de 36,1 años y en los que la local…
Mutations in theMORC2gene cause axonal Charcot–Marie–Tooth disease
2015
Charcot-Marie-Tooth disease (CMT) is a complex disorder with wide genetic heterogeneity. Here we present a new axonal Charcot-Marie-Tooth disease form, associated with the gene microrchidia family CW-type zinc finger 2 (MORC2). Whole-exome sequencing in a family with autosomal dominant segregation identified the novel MORC2 p.R190W change in four patients. Further mutational screening in our axonal Charcot-Marie-Tooth disease clinical series detected two additional sporadic cases, one patient who also carried the same MORC2 p.R190W mutation and another patient that harboured a MORC2 p.S25L mutation. Genetic and in silico studies strongly supported the pathogenicity of these sequence variant…
Myelin Proteome Analysis: Methods and Implications for the Myelin Cytoskeleton
2012
Myelin, the multilayered membrane that enwraps and insulates neuronal axons for fast signal propagation, is a plasma membrane specialization of oligodendrocytes and Schwann cells in the central and peripheral nervous system, respectively. Here we provide our lab protocols for the puri fi cation of myelin from mouse brains and for gel-based and gel-free proteomic applications, as well as a brief discussion with respect to our current knowledge of the myelin cytoskeleton.
Basics of anatomy
2017
Peripheral nerves contain motor, sensory, and vegetative fibers that are strictly separate, but in close proximity to each other (Figure 1).