scholarly journals Ion Channels as New Attractive Targets to Improve Re-Myelination Processes in the Brain

2021 ◽  
Vol 22 (14) ◽  
pp. 7277
Author(s):  
Federica Cherchi ◽  
Irene Bulli ◽  
Martina Venturini ◽  
Anna Maria Pugliese ◽  
Elisabetta Coppi

Multiple sclerosis (MS) is the most demyelinating disease of the central nervous system (CNS) characterized by neuroinflammation. Oligodendrocyte progenitor cells (OPCs) are cycling cells in the developing and adult CNS that, under demyelinating conditions, migrate to the site of lesions and differentiate into mature oligodendrocytes to remyelinate damaged axons. However, this process fails during disease chronicization due to impaired OPC differentiation. Moreover, OPCs are crucial players in neuro-glial communication as they receive synaptic inputs from neurons and express ion channels and neurotransmitter/neuromodulator receptors that control their maturation. Ion channels are recognized as attractive therapeutic targets, and indeed ligand-gated and voltage-gated channels can both be found among the top five pharmaceutical target groups of FDA-approved agents. Their modulation ameliorates some of the symptoms of MS and improves the outcome of related animal models. However, the exact mechanism of action of ion-channel targeting compounds is often still unclear due to the wide expression of these channels on neurons, glia, and infiltrating immune cells. The present review summarizes recent findings in the field to get further insights into physio-pathophysiological processes and possible therapeutic mechanisms of drug actions.

Author(s):  
Roger L. Papke

Acetylcholine, exquisitely evolved as a neurotransmitter, is made and released by the neurons that take the integrated output of the central nervous system throughout the body. At both neuromuscular junctions and autonomic ganglia, acetylcholine activates synaptic ion channels that take their name from the plant alkaloid nicotine, which is a mimic of the natural neurotransmitter. This chapter begins with the scientific discoveries related to the nicotinic acetylcholine receptors (nAChR) of the neuromuscular junction and how resulting insights led to an understanding of the fundamentals of synaptic transmission. The nAChR are one member of a superfamily of ligand-gated ion channels, and although in the brain excitatory neurotransmission is mediated by another family of synaptic receptors that are gated by glutamate, nicotinic receptors are important modulators of brain function and significant targets for drug development. In the brain, nAChR are targets for cognitive disorders and, tragically, responsible for tobacco addiction.


Development ◽  
2001 ◽  
Vol 128 (10) ◽  
pp. 1757-1769 ◽  
Author(s):  
C. Olivier ◽  
I. Cobos ◽  
E.M. Perez Villegas ◽  
N. Spassky ◽  
B. Zalc ◽  
...  

Oligodendrocytes are the myelin-forming cells in the central nervous system. In the brain, oligodendrocyte precursors arise in multiple restricted foci, distributed along the caudorostral axis of the ventricular neuroepithelium. In chick embryonic hind-, mid- and caudal forebrain, oligodendrocytes have a basoventral origin, while in the rostral fore-brain oligodendrocytes emerge from alar territories (Perez Villegas, E. M., Olivier, C., Spassky, N., Poncet, C., Cochard, P., Zalc, B., Thomas, J. L. and Martinez, S. (1999) Dev. Biol. 216, 98–113). To investigate the respective territories colonized by oligodendrocyte progenitor cells that originate from either the basoventral or alar foci, we have created a series of quail-chick chimeras. Homotopic chimeras demonstrate clearly that, during embryonic development, oligodendrocyte progenitors that emerge from the alar anterior entopeduncular area migrate tangentially to invade the entire telencephalon, whereas those from the basal rhombomeric foci show a restricted rostrocaudal distribution and colonize only their rhombomere of origin. Heterotopic chimeras indicate that differences in the migratory properties of oligodendroglial cells do not depend on their basoventral or alar ventricular origin. Irrespective of their origin (basal or alar), oligodendrocytes migrate only short distances in the hindbrain and long distances in the prosencephalon. Furthermore, we provide evidence that, in the developing chick brain, all telencephalic oligodendrocytes originate from the anterior entopeduncular area and that the prominent role of anterior entopeduncular area in telencephalic oligodendrogenesis is conserved between birds and mammals.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Deborah R. Morris ◽  
Cathy W. Levenson

Ionotropic glutamate receptors, such as NMDA, AMPA and kainate receptors, are ligand-gated ion channels that mediate much of the excitatory neurotransmission in the brain. Not only do these receptors bind glutamate, but they are also regulated by and facilitate the postsynaptic uptake of the trace metal zinc. This paper discusses the role of the excitotoxic influx and accumulation of zinc, the mechanisms responsible for its cytotoxicity, and a number of disorders of the central nervous system that have been linked to these neuronal ion channels and zinc toxicity including ischemic brain injury, traumatic brain injury, and epilepsy.


2020 ◽  
Author(s):  
Luiza Stanaszek ◽  
Malgorzata Majchrzak ◽  
Katarzyna Drela ◽  
Piotr Rogujski ◽  
Joanna Sanford ◽  
...  

Abstract Background: Dysfunction of glia contributes to the deterioration of the central nervous system in a wide array of neurological disorders, thus global replacement strategies of glia are very attractive. Human glial restricted precursors (hGRPs) transplanted intraventricularly into neonatal mice extensively migrated and rescued lifespan in half of studied mice, while mouse GRPs (mGRPs) presented no therapeutic benefit. We hypothesized that the intrinsic developmental program (IDP) might be one of the main drivers of cell behaviour after grafting, with long migration distance and late myelination for hGRPs, compared to limited migration and early myelination for mGRPs. We studied in the same experimental setting canine GRPs (cGRP) to determine whether their migration, myelination and subsequent therapeutic potential falls between hGRPs and mGRPs. Additional motivation for selection of cGRPs was a potential for use in veterinary medicine due to growing population of dogs as companion animals. Methods: cGRPs were extracted from the brain of dog foetuses. The cells transplanted (4x105 cells) into anterior or posterior aspect of the lateral ventricle (LV) of neonatal, immunodeficient, dysmyelinated mice (shiverer, MBPshi/shi, rag2-/-). Outcome measures included early cell biodistribution, animal survival and myelination assessed with MRI, immunohistochemistry and electron microscopy. Results: Grafting of cGRP into posterior LV significantly extended animal survival, while no benefit was observed after anterior LV transplantation. In contrast, myelination of the corpus callosum was more prominent in anteriorly transplanted animals. Conclusions: The extended survival of animals after transplantation of cGRPs could be explained by the vicinity of transplant near the brain stem.


2012 ◽  
Vol 199 (3) ◽  
pp. 413-416 ◽  
Author(s):  
Lawrence Steinman

Multiple sclerosis (MS) is the major inflammatory demyelinating disease of the central nervous system. There is strong evidence that an immune response in the brain is a critical component of the disease. In 1992, in a collaboration between academia and biotechnology, my colleagues and I showed that α4 integrin was the critical molecule involved in the homing of immune cells into the inflamed brain. Was it sheer luck that these results led to the development of a drug for MS?


1981 ◽  
Vol 55 (4) ◽  
pp. 620-624 ◽  
Author(s):  
Kenneth G. Rieth ◽  
Giovanni Di Chiro ◽  
Laurence D. Cromwell ◽  
Paul E. McKeever ◽  
Paul L. Kornblith ◽  
...  

✓ Computerized tomography (CT) has made it easier to distinguish tumoral from nontumoral diseases of the central nervous system. In the presence of mass effect, however, this distinction may be difficult or impossible to make. Primary demyelinating disease may occasionally present as a focal cerebral mass. The authors report three cases of primary demyelinating disease of the brain involving the corpus callosum and periventricular white matter and associated with mass effect, which proved difficult to differentiate from infiltrating “butterfly” gliomas.


Author(s):  
Katharina Held ◽  
Balázs István Tóth

Already for centuries, humankind is driven to understand the physiological and pathological mechanisms that occur in our brains. Today, we know that ion channels play an essential role in the regulation of neural processes and control many functions of the central nervous system. Ion channels present a diverse group of membrane-spanning proteins that allow ions to penetrate the insulating cell membrane upon opening of their channel pores. This regulated ion permeation results in different electrical and chemical signals that are necessary to maintain physiological excitatory and inhibitory processes in the brain. Therefore, it is no surprise that disturbances in the functions of cerebral ion channels can result in a plethora of neurological disorders, which present a tremendous health care burden for our current society. The identification of ion channel-related brain disorders also fuel the research into the roles of ion channel proteins in various brain states. In the last decade, mounting evidence has been collected that indicates a pivotal role for transient receptor potential (TRP) ion channels in the development and various physiological functions of the central nervous system. For instance, TRP channels modulate neurite growth, synaptic plasticity and integration, and are required for neuronal survival. Moreover, TRP channels are involved in numerous neurological disorders. TRPM3 belongs to the melastatin subfamily of TRP channels and represents a non-selective cation channel that can be activated by several different stimuli, including the neurosteroid pregnenolone sulfate, osmotic pressures and heat. The channel is best known as a peripheral nociceptive ion channel that participates in heat sensation. However, recent research identifies TRPM3 as an emerging new player in the brain. In this review, we summarize the available data regarding the roles of TRPM3 in the brain, and correlate these data with the neuropathological processes in which this ion channel may be involved.


2021 ◽  
Author(s):  
Ezzat Hashemi ◽  
Hsing-Chuan Tsai ◽  
Ezra Yoseph ◽  
Monica Moreno ◽  
Li-Hao Yeh ◽  
...  

Abstract Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) mediated by aberrant immune responses. The current immune modulatory therapies are unable to protect and repair the brain damage caused by the immune attack. One of the therapeutic targets for MS is the sphingosine-1-phosphate (S1P) pathways, which signals via sphingosine-1-phosphate receptors 1-5 (S1P1-5), in the CNS and immune cells. In light of the potential neuro-protective properties of S1P signaling, we utilized the S1P1-GFP (Green fluorescent protein) reporter mice in the cuprizone-induced-demyelination model, to investigate the in vivo S1P- S1P1 signaling in the CNS. We observed S1P1 signaling in a subset of neural stem cells in the subventricular zone (SVZ) during demyelination. Additionally, oligodendrocyte progenitor cells in the SVZ and mature oligodendrocytes in the medial corpus callosum (MCC) expressed S1P1 signaling during remyelination. We did not observe S1P1 signaling in neurons and astrocytes in the cuprizone model. This approach was unable to determine S1P1-GFP signaling in the myeloid cells because of their aberrant GFP expression in GFP reporter mice. Significant S1P1 signaling was observed in lymphocytes during demyelination and inflammation. Our findings reveal β-arrestin dependent S1P1 signaling in oligodendrocyte lineage cells, indicating a role of S1P1 signaling during remyelination.


Author(s):  
Hannah R. Brown ◽  
Tammy L. Donato ◽  
Halldor Thormar

Measles virus specific immunoglobulin G (IgG) has been found in the brains of patients with subacute sclerosing panencephalitis (SSPE), a slowly progressing disease of the central nervous system (CNS) in children. IgG/albumin ratios indicate that the antibodies are synthesized within the CNS. Using the ferret as an animal model to study the disease, we have been attempting to localize the Ig's in the brains of animals inoculated with a cell associated strain of SSPE. In an earlier report, preliminary results using Protein A conjugated to horseradish peroxidase (PrAPx) (Dynatech Diagnostics Inc., South Windham, ME.) to detect antibodies revealed the presence of immunoglobulin mainly in antibody-producing plasma cells in inflammatory lesions and not in infected brain cells.In the present experiment we studied the brain of an SSPE ferret with neutralizing antibody titers of 1:1024 in serum and 1:512 in CSF at time of sacrifice 7 months after i.c. inoculation with SSPE measles virus-infected cells. The animal was perfused with saline and portions of the brain and spinal cord were immersed in periodate-lysine-paraformaldehyde (P-L-P) fixative. The ferret was not perfused with fixative because parts of the brain were used for virus isolation.


Author(s):  
S.S. Spicer ◽  
B.A. Schulte

Generation of monoclonal antibodies (MAbs) against tissue antigens has yielded several (VC1.1, HNK- 1, L2, 4F4 and anti-leu 7) which recognize the unique sugar epitope, glucuronyl 3-sulfate (Glc A3- SO4). In the central nervous system, these MAbs have demonstrated Glc A3-SO4 at the surface of neurons in the cerebral cortex, the cerebellum, the retina and other widespread regions of the brain.Here we describe the distribution of Glc A3-SO4 in the peripheral nervous system as determined by immunostaining with a MAb (VC 1.1) developed against antigen in the cat visual cortex. Outside the central nervous system, immunoreactivity was observed only in peripheral terminals of selected sensory nerves conducting transduction signals for touch, hearing, balance and taste. On the glassy membrane of the sinus hair in murine nasal skin, just deep to the ringwurt, VC 1.1 delineated an intensely stained, plaque-like area (Fig. 1). This previously unrecognized structure of the nasal vibrissae presumably serves as a tactile end organ and to our knowledge is not demonstrable by means other than its selective immunopositivity with VC1.1 and its appearance as a densely fibrillar area in H&E stained sections.


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