scholarly journals Transmembrane protease serine 5: a novel Schwann cell plasma marker for CMT1A

2019 ◽  
Vol 7 (1) ◽  
pp. 69-82 ◽  
Author(s):  
Hongge Wang ◽  
Matthew Davison ◽  
Kathryn Wang ◽  
Tai‐He Xia ◽  
Martin Kramer ◽  
...  
Keyword(s):  
Schwann Cell ◽  
Cell Plasma ◽  
Plasma Marker

scholarly journals A murine model of Charcot-Marie-Tooth disease 4F reveals a role for the C-terminus of periaxin in the formation and stabilization of Cajal bands

2018 ◽  
Vol 3 ◽  
pp. 20 ◽  
Author(s):  
Diane L. Sherman ◽  
Peter J. Brophy
Keyword(s):  
Plasma Membrane ◽  
Schwann Cell ◽  
Laminin Receptor ◽  
Cell Plasma Membrane ◽  
Charcot Marie Tooth ◽  
Charcot Marie Tooth Disease ◽  
C Terminus ◽  
Cell Plasma ◽  
Inherited Neuropathies ◽  
Tooth Disease

Charcot-Marie-Tooth (CMT) disease comprises up to 80 monogenic inherited neuropathies of the peripheral nervous system (PNS) that collectively result in demyelination and axon degeneration. The majority of CMT disease is primarily either dysmyelinating or demyelinating in which mutations affect the ability of Schwann cells to either assemble or stabilize peripheral nerve myelin. CMT4F is a recessive demyelinating form of the disease caused by mutations in the Periaxin (PRX) gene. Periaxin (Prx) interacts with Dystrophin Related Protein 2 (Drp2) in an adhesion complex with the laminin receptor Dystroglycan (Dag). In mice the Prx/Drp2/Dag complex assembles adhesive domains at the interface between the abaxonal surface of the myelin sheath and the cytoplasmic surface of the Schwann cell plasma membrane. Assembly of these appositions causes the formation of cytoplasmic channels called Cajal bands beneath the surface of the Schwann cell plasma membrane. Loss of either Periaxin or Drp2 disrupts the appositions and causes CMT in both mouse and man. In a mouse model of CMT4F, complete loss of Periaxin first prevents normal Schwann cell elongation resulting in abnormally short internodal distances which can reduce nerve conduction velocity, and subsequently precipitates demyelination. Distinct functional domains responsible for Periaxin homodimerization and interaction with Drp2 to form the Prx/Drp2/Dag complex have been identified at the N-terminus of Periaxin. However, CMT4F can also be caused by a mutation that results in the truncation of Periaxin at the extreme C-terminus with the loss of 391 amino acids. By modelling this in mice, we show that loss of the C-terminus of Periaxin results in a surprising reduction in Drp2. This would be predicted to cause the observed instability of both appositions and myelin, and contribute significantly to the clinical phenotype in CMT4F.

scholarly journals ISOLATION AND CHARACTERIZATION OF PLASMA MEMBRANE FRACTIONS FROM GARFISH LEPISOSTEUS OSSEUS OLFACTORY NERVE

1974 ◽  
Vol 62 (3) ◽  
pp. 831-843 ◽  
Author(s):  
George K. Chacko ◽  
David E. Goldman ◽  
Harish C. Malhotra ◽  
Maynard M. Dewey
Keyword(s):  
Plasma Membrane ◽  
Schwann Cell ◽  
Plasma Membranes ◽  
Sodium Dodecyl ◽  
Olfactory Nerve ◽  
Membrane Thickness ◽  
Axonal Membrane ◽  
Isolation And Characterization ◽  
Cell Plasma ◽  
Fraction I

Garfish Lepisosteus osseus olfactory nerve, because of its large size and the unusually high concentration of axonal membrane, is an excellent source of axonal membrane. A procedure is described for the isolation of two types of plasma membranes from the nerve which are obtained in yields of about 20 mg (fraction I) and 1.5 mg (fraction II) per g of wet nerve. Both membrane fractions consist mostly of rounded membrane vesicles, with a unit membrane thickness of ∼7.5 nm. The two membrane fractions are different in their lipid to protein ratios, Na-K ATPase activities, polypeptide patterns on sodium dodecyl sulfate (SDS) gel electrophoresis, and fatty acid compositions. They have similar phospholipid composition. On the basis of the relative concentration of axonal and Schwann cell plasma membranes in the nerve, the Na-K ATPase activities of the two membrane fractions and a comparison of the properties of the membrane fractions to those of squid and lobster nerve membrane preparations, fraction I seems to be the axonal membrane and fraction II the Schwann cell plasma membrane. Fraction I has a low protein to lipid ratio. Its polypeptide pattern on SDS gel appears to be much more complex as compared to that of fraction II membrane.

scholarly journals Immunocytochemical studies of quaking mice support a role for the myelin-associated glycoprotein in forming and maintaining the periaxonal space and periaxonal cytoplasmic collar of myelinating Schwann cells.

1984 ◽  
Vol 99 (2) ◽  
pp. 594-606 ◽  
Author(s):  
B D Trapp ◽  
R H Quarles ◽  
K Suzuki
Keyword(s):  
Schwann Cell ◽  
Schwann Cells ◽  
Plasma Membranes ◽  
Immunocytochemical Localization ◽  
Myelinated Fibers ◽  
Cell Plasma ◽  
Myelin Associated Glycoprotein ◽  
Quaking Mice ◽  
Periaxonal Space ◽  
Cytoplasmic Side

The myelin-associated glycoprotein (MAG) is an integral membrane glycoprotein that is located in the periaxonal membrane of myelin-forming Schwann cells. On the basis of this localization, it has been hypothesized that MAG plays a structural role in (a) forming and maintaining contact between myelinating Schwann cells and the axon (the 12-14-nm periaxonal space) and (b) maintaining the Schwann cell periaxonal cytoplasmic collar of myelinated fibers. To test this hypothesis, we have determined the immunocytochemical localization of MAG in the L4 ventral roots from 11-mo-old quaking mice. These roots display various stages in the association of remyelinating Schwann cells with axons, and abnormalities including loss of the Schwann cell periaxonal cytoplasmic collar and dilation of the periaxonal space of myelinated fibers. Therefore, this mutant provides distinct opportunities to observe the relationships between MAG and (a) the formation of the periaxonal space during remyelination and (b) the maintenance of the periaxonal space and Schwann cell periaxonal cytoplasmic collar in myelinated fibers. During association of remyelinating Schwann cells and axons, MAG was detected in Schwann cell adaxonal membranes that apposed the axolemma by 12-14 nm. Schwann cell plasma membranes separated from the axolemma by distances greater than 12-14 nm did not react with MAG antiserum. MAG was present in adaxonal Schwann cell membranes that apposed the axolemma by 12-14 nm but only partially surrounded the axon and, therefore, may be actively involved in the ensheathment of axons by remyelinating Schwann cells. To test the dual role of MAG in maintaining the periaxonal space and Schwann cell periaxonal cytoplasmic collar of myelinated fibers, we determined the immunocytochemical localization of MAG in myelinated quaking fibers that displayed pathological alterations of these structures. Where Schwann cell periaxonal membranes were not stained by MAG antiserum, the cytoplasmic side of the periaxonal membrane was "fused" with the cytoplasmic side of the inner compact myelin lamella and formed a major dense line. This loss of MAG and the Schwann cell periaxonal cytoplasmic collar usually resulted in enlargement of the 12-14-nm periaxonal space and ruffling of the apposing axolemma. In myelinated fibers, there was a strict correlation between the presence of MAG in the Schwann cell periaxonal membrane and (a) maintenance of the 12-14-nm periaxonal space, and (b) presence of the Schwann cell periaxonal cytoplasmic collar.(ABSTRACT TRUNCATED AT 400 WORDS)

Evidence for Regulation of Myelin Protein Synthesis by Contact between Adjacent Schwann Cell Plasma Membranes

1999 ◽  
Vol 21 (6) ◽  
pp. 417-422 ◽  
Author(s):  
Naokazu Sasagasako ◽  
Masaharu Ohno ◽  
Richard H. Quarles
Keyword(s):  
Protein Synthesis ◽  
Schwann Cell ◽  
Plasma Membranes ◽  
Myelin Protein ◽  
Cell Plasma

Schwann cell plasma membrane changes induced by nerve crush

1980 ◽  
Vol 50 (2) ◽  
pp. 85-90 ◽  
Author(s):  
P. H. Abrahams ◽  
A. Day ◽  
G. Allt
Keyword(s):  
Plasma Membrane ◽  
Schwann Cell ◽  
Cell Plasma Membrane ◽  
Nerve Crush ◽  
Cell Plasma ◽  
Membrane Changes

scholarly journals Autoradiographic localization of acetylcholine receptors in the Schwann cell membrane of the squid nerve fiber

1978 ◽  
Vol 77 (2) ◽  
pp. 371-376 ◽  
Author(s):  
FA Rawlins ◽  
J Villegas
Keyword(s):  
Schwann Cell ◽  
Nerve Fiber ◽  
Acetylcholine Receptors ◽  
Cell Layer ◽  
Nerve Fibers ◽  
Electron Microscope Autoradiography ◽  
Radioactive Label ◽  
Cell Plasma ◽  
Intercellular Channels ◽  
Alpha Bungarotoxin

Intact and slit nerve fibers of the squid Sepioteuthis sepioidea were incubated in a 50-nM solution of [125I] alpha-bungarotoxin in artificial seawater, in the absence and in the presence of D-tubocurarine (10(-4) M). The distribution of the radioactive label was then determined by electron microscope autoradiography. It was found that, in the fibers exposed solely to the radioactive toxin, the label was located mainly at the axon-Schwann cell boundary in the intact nerve fibers or at the axonal edge of the Schwann cell layer in the axon-free nerve fiber sheaths. Label was also present in those regions of the Schwann cell layer rich in intercellular channels. No signs of radioactivity were observed in the nerve fibers exposed to the labeled toxin in the presence of D-tubocurarine. These results indicate that the acetycholine receptors previously found in the Schwann cell plasma membrane are mainly located over the cell surfaces facing the neighboring axon and the adjacent Schwann cells. These findings represent a further advance in the understanding of the relationship between the axon and its satellite Schwann cell.

Human Neurofibromas in Co-Culture with Mouse Neurons

1982 ◽  
Vol 40 ◽  
pp. 194-195
Author(s):  
R.L. Martuza ◽  
T. Liszczak ◽  
A. Okun ◽  
T-Y Wang
Keyword(s):  
Schwann Cell ◽  
Schwann Cells ◽  
Genetic Disorder ◽  
Cranial Nerves ◽  
Sympathetic Nerves ◽  
Acoustic Neuromas ◽  
Spinal Roots ◽  
Neural Crest Origin ◽  
Multiple Abnormalities ◽  
Other Neoplasms

Neurofibromatosis (NF) is an autosomal dominant genetic disorder with a prevalence of 1/3,000 births. The NF mutation causes multiple abnormalities of various cells of neural crest origin. Schwann cell tumors (neurofibromas, acoustic neuromas) are the most common feature of neurofibromatosis although meningiomas, gliomas, and other neoplasms may be seen. The schwann cell tumors commonly develop from the schwann cells associated with sensory or sympathetic nerves or their ganglia. Schwann cell tumors on ventral spinal roots or motor cranial nerves are much less common. Since the sensory neuron membrane is known to contain a mitogenic factor for schwann cells, we have postulated that neurofibromatosis may be due to an abnormal interaction between the nerve and the schwann cell and that this interaction may be hormonally modulated. To test this possibility a system has been developed in which an enriched schwannoma cell culture can be obtained and co-cultured with pure neurons.

Platelet Incorporation of Labelled Adenosine and Adenosine Diphosphate

1969 ◽  
Vol 22 (02) ◽  
pp. 304-315 ◽  
Author(s):  
E. W Salzman ◽  
T. P Ashford ◽  
D. A Chambers ◽  
Lena L. Neri
Keyword(s):  
Platelet Rich Plasma ◽  
Adenosine Diphosphate ◽  
Platelet Inhibition ◽  
Electron Microscopic ◽  
Platelet Binding ◽  
Minor Degree ◽  
A Minor ◽  
Plasma Marker ◽  
Electron Microscopic Radioautography ◽  
Simultaneous Assessment

SummaryAfter incubation of platelet-rich plasma with labelled adenosine or ADP, platelet incorporation of radioactivity was assessed. Platelets were rapidly separated for counting by filtration through cellulose acetate Millipore. Inulin-H3 served as a plasma marker, and triple isotope techniques permitted simultaneous assessment of the behavior of the adenine and phosphate moieties of ADP without washing of platelets. In other experiments, electron microscopic radioautography was employed to trace the label after platelet incorporation.The results were consistent with previous reports that ADP is dephosphorylated in plasma and is incorporated by platelets only as a dephosphorylated residue, probably adenosine. The label crossed the platelet membrane and entered the platelet, where it was distributed in platelet granules and the agranular cell sap. Concentration within granules occurred to a minor degree.The results support the hypothesis that platelet aggregation by ADP occurs without a persistent bond of ADP to the platelet. Inhibition of aggregation by adenosine probably depends on a metabolic or transport process rather than on competition between adenosine and ADP for platelet binding sites.

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