scholarly journals A Matter of State: Diversity in Oligodendrocyte Lineage Cells

2021 ◽  
pp. 107385842098720
Author(s):  
Yasmine Kamen ◽  
Helena Pivonkova ◽  
Kimberley A. Evans ◽  
Ragnhildur T. Káradóttir
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Adult Brain ◽  
Developmental Origins ◽  
Oligodendrocyte Precursor Cells ◽  
Homogeneous Population ◽  
Physiological Properties ◽  
The Central Nervous System ◽  
Oligodendrocyte Precursor ◽  
Transcriptome Response

Oligodendrocyte precursor cells (OPCs) give rise to oligodendrocytes which myelinate axons in the central nervous system. Although classically thought to be a homogeneous population, OPCs are reported to have different developmental origins and display regional and temporal diversity in their transcriptome, response to growth factors, and physiological properties. Similarly, evidence is accumulating that myelinating oligodendrocytes display transcriptional heterogeneity. Analyzing this reported heterogeneity suggests that OPCs, and perhaps also myelinating oligodendrocytes, may exist in different functional cell states. Here, we review the evidence indicating that OPCs and oligodendrocytes are diverse, and we discuss the implications of functional OPC states for myelination in the adult brain and for myelin repair.

scholarly journals γ–Secretase controls the specification of astrocytes from oligodendrocyte precursor cells via Stat3

2019 ◽  
Author(s):  
Jinxing Hou ◽  
Huiru Bi ◽  
Gang Zou ◽  
Zhuoyang Ye ◽  
Jing Zhao ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Postnatal Development ◽  
Precursor Cells ◽  
Oligodendrocyte Precursor Cells ◽  
Signal Transducer ◽  
Brain Functions ◽  
Mechanistic Analysis ◽  
The Central Nervous System ◽  
Oligodendrocyte Precursor

AbstractOligodendrocytes (OLs) and astrocytes play critical roles in a variety of brain functions. OL precursor cells (OPCs) are known to give rise to OLs as well as astrocytes. However, little is known about the mechanism by which OPCs determine their specification choice for OLs versus astrocytes in the central nervous system (CNS). Here we show that genetic inhibition of γ-secretase in OPCs reduces OL differentiation but enhances astrocyte specification. Mechanistic analysis reveals that inhibition of γ-secretase results in decreased levels of Hes1, and that Hes1 down-regulates the expression of signal transducer and activator of transcription3 (Stat3) via binding to specific regions of its promoter. We demonstrate that conditional inactivation of Stat3 in OL lineages restores the number of astrocytes in γ-secretase mutant mice. In summary, this study identifies a key mechanism which controls OPC’s specification choice for OL versus astrocyte during postnatal development. This γ-secretase-dependent machinery may be essential for the CNS to maintain the population balance between OLs and astrocytes.

Heterogeneity and Proliferative and Differential Regulators of NG2-glia in Physiological and Pathological States

2020 ◽  
Vol 27 (37) ◽  
pp. 6384-6406 ◽  
Author(s):  
Zuo Zhang ◽  
Hongli Zhou ◽  
Jiyin Zhou
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Physiological State ◽  
Critical Role ◽  
Adult Brain ◽  
Pathological State ◽  
Peripheral Neurons ◽  
Neuronal Synapses ◽  
The Central Nervous System ◽  
Rapid Modulation

NG2-glia, also called Oligodendrocyte Precursor Cells (OPCs), account for approximately 5%-10% of the cells in the developing and adult brain and constitute the fifth major cell population in the central nervous system. NG2-glia express receptors and ion channels involved in rapid modulation of neuronal activities and signaling with neuronal synapses, which have functional significance in both physiological and pathological states. NG2-glia participate in quick signaling with peripheral neurons via direct synaptic touches in the developing and mature central nervous system. These distinctive glia perform the unique function of proliferating and differentiating into oligodendrocytes in the early developing brain, which is critical for axon myelin formation. In response to injury, NG2-glia can proliferate, migrate to the lesions, and differentiate into oligodendrocytes to form new myelin sheaths, which wrap around damaged axons and result in functional recovery. The capacity of NG2-glia to regulate their behavior and dynamics in response to neuronal activity and disease indicate their critical role in myelin preservation and remodeling in the physiological state and in repair in the pathological state. In this review, we provide a detailed summary of the characteristics of NG2-glia, including their heterogeneity, the regulators of their proliferation, and the modulators of their differentiation into oligodendrocytes.

scholarly journals The Role of Mast Cells in Stroke

Cells ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 437 ◽  
Author(s):  
Edoardo Parrella ◽  
Vanessa Porrini ◽  
Marina Benarese ◽  
Marina Pizzi
Keyword(s):  
Central Nervous System ◽  
Immune Response ◽  
Nervous System ◽  
Mast Cells ◽  
Brain Edema ◽  
Hemorrhagic Stroke ◽  
Inflammatory Responses ◽  
Adult Brain ◽  
The Central Nervous System

Mast cells (MCs) are densely granulated perivascular resident cells of hematopoietic origin. Through the release of preformed mediators stored in their granules and newly synthesized molecules, they are able to initiate, modulate, and prolong the immune response upon activation. Their presence in the central nervous system (CNS) has been documented for more than a century. Over the years, MCs have been associated with various neuroinflammatory conditions of CNS, including stroke. They can exacerbate CNS damage in models of ischemic and hemorrhagic stroke by amplifying the inflammatory responses and promoting brain–blood barrier disruption, brain edema, extravasation, and hemorrhage. Here, we review the role of these peculiar cells in the pathophysiology of stroke, in both immature and adult brain. Further, we discuss the role of MCs as potential targets for the treatment of stroke and the compounds potentially active as MCs modulators.

scholarly journals Tissue-specific expression of the heat shock protein HSP27 during Drosophila melanogaster development.

1990 ◽  
Vol 111 (3) ◽  
pp. 817-828 ◽  
Author(s):  
D Pauli ◽  
C H Tonka ◽  
A Tissieres ◽  
A P Arrigo
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Drosophila Melanogaster ◽  
Heat Shock ◽  
Stress Protein ◽  
Pupal Stage ◽  
Adult Brain ◽  
Proliferating Cells ◽  
Specific Expression ◽  
The Central Nervous System

The alpha-crystallin-related heat shock (stress) protein hsp27 is expressed in absence of heat shock during Drosophila melanogaster development. Here, we describe the tissue distribution of this protein using an immunoaffinity-purified antibody. In embryos, hsp27 translated from maternal RNA is uniformly distributed, except in the yolk. During the first, second, and early third larval stages, hsp27 expression is restricted to the brain and the gonads. These tissues are characterized by a high level of proliferating cells. In late third instar larvae and early pupae, in addition to the central nervous system and the gonads, all the imaginal discs synthesize hsp27. The disc expression seems restricted to the beginning of their differentiation since it disappears during the second half of the pupal stage: no more hsp27 is observed in the disc-derived adult organs. In adults, hsp27 is still present in some regions of the central nervous system, and is also expressed in the male and female germ lines where it accumulates in mature sperm and oocytes. The transcript and the protein accumulate in oocytes since the onset of vitellogenesis with a uniform distribution similar to that found in embryos. The adult germ lines transcribe hsp27 gene while no transcript is detected in the late pupal and adult brain. These results suggest multiple roles of hsp27 during Drosophila development which may be related to both the proliferative and differentiated states of the tissues.

scholarly journals Extracellular histone H1 is neurotoxic and drives a pro-inflammatory response in microglia

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 148 ◽  
Author(s):  
Jonathan D Gilthorpe ◽  
Fazal Oozeer ◽  
Julia Nash ◽  
Margarita Calvo ◽  
David LH Bennett ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Mhc Class Ii ◽  
Cortical Neurons ◽  
Antigen Expression ◽  
Histone H1 ◽  
Adult Brain ◽  
Core Histones ◽  
The Central Nervous System ◽  
Class Ii Antigen

In neurodegenerative conditions and following brain trauma it is not understood why neurons die while astrocytes and microglia survive and adopt pro-inflammatory phenotypes. We show here that the damaged adult brain releases diffusible factors that can kill cortical neurons and we have identified histone H1 as a major extracellular candidate that causes neurotoxicity and activation of the innate immune system. Extracellular core histones H2A, H2B H3 and H4 were not neurotoxic. Innate immunity in the central nervous system is mediated through microglial cells and we show here for the first time that histone H1 promotes their survival, up-regulates MHC class II antigen expression and is a powerful microglial chemoattractant. We propose that when the central nervous system is degenerating, histone H1 drives a positive feedback loop that drives further degeneration and activation of immune defences which can themselves be damaging. We suggest that histone H1 acts as an antimicrobial peptide and kills neurons through mitochondrial damage and apoptosis.

Quantitative Mapping of Cutaneous Receptive Fields in Normal and Operated Leeches, Limnobdella

1978 ◽  
Vol 76 (1) ◽  
pp. 167-179
Author(s):  
MICHAEL J. FETT
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Receptive Field ◽  
Receptive Fields ◽  
Distal Dendrite ◽  
Quantitative Mapping ◽  
Physiological Properties ◽  
The Central Nervous System

1. The receptive fields and physiological properties of the sensitive cutaneous mechanoreceptive neurones in the leech Limnobdella austraits were found to be very similar to those previously described in Hirudo medidnalis. 2. Following separation from the central nervous system (C.N.S.), the distal dendrite stump and cutaneous receptive field remained unchanged for at least 160 days. 3. There was little spreading of receptive fields into regions of skin isolated from the C.N.S. for at least 184 days. 4. Cutting one dendrite of a mechanoreceptive neurone which has two major dendrites produced little change in the receptive field of the intact dendrite. 5. Abnormalities were found in most of the receptive fields of operated leeches, irrespective of the site of operation. These abnormalities were not seen in normal leeches.

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