Glial development in the Drosophila CNS requires concomitant activation of glial and repression of neuronal differentiation genes

Development ◽  
1997 ◽  
Vol 124 (12) ◽  
pp. 2307-2316 ◽  
Author(s):  
K. Giesen ◽  
T. Hummel ◽  
A. Stollewerk ◽  
S. Harrison ◽  
A. Travers ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Neuronal Differentiation ◽  
Glial Cell ◽  
Glial Cells ◽  
Neuronal Development ◽  
Egf Receptor ◽  
Dual Process ◽  
Glial Development ◽  
Receptor Signalling ◽  
Cns Midline

Two classes of glial cells are found in the embryonic Drosophila CNS, midline glial cells and lateral glial cells. Midline glial development is triggered by EGF-receptor signalling, whereas lateral glial development is controlled by the gcm gene. Subsequent glial cell differentiation depends partly on the pointed gene. Here we describe a novel component required for all CNS glia development. The tramtrack gene encodes two zinc-finger proteins, one of which, ttkp69, is expressed in all non-neuronal CNS cells. We show that ttkp69 is downstream of gcm and can repress neuronal differentiation. Double mutant analysis and coexpression experiments indicate that glial cell differentiation may depend on a dual process, requiring the activation of glial differentiation by pointed and the concomitant repression of neuronal development by tramtrack.

Differential effects of EGF receptor signalling on neuroblast lineages along the dorsoventral axis of the Drosophila CNS

Development ◽  
1998 ◽  
Vol 125 (17) ◽  
pp. 3291-3299 ◽  
Author(s):  
G. Udolph ◽  
J. Urban ◽  
G. Rusing ◽  
K. Luer ◽  
G.M. Technau
Keyword(s):  
Cell Fate ◽  
Egf Receptor ◽  
Cell Lineage ◽  
Dorsoventral Patterning ◽  
Cell Fates ◽  
Regulatory Pathways ◽  
Differential Effects ◽  
Receptor Signalling ◽  
Cns Midline ◽  
Lineage Analysis

The Drosophila ventral nerve cord derives from a stereotype population of about 30 neural stem cells, the neuroblasts, per hemineuromere. Previous experiments provided indications for inductive signals at ventral sites of the neuroectoderm that confer neuroblast identities. Using cell lineage analysis, molecular markers and cell transplantation, we show here that EGF receptor signalling plays an instructive role in CNS patterning and exerts differential effects on dorsoventral subpopulations of neuroblasts. The Drosophila EGF receptor (DER) is capable of cell autonomously specifiying medial and intermediate neuroblast cell fates. DER signalling appears to be most critical for proper development of intermediate neuroblasts and less important for medial neuroblasts. It is not required for lateral neuroblast lineages or for cells to adopt CNS midline cell fate. Thus, dorsoventral patterning of the CNS involves both DER-dependent and -independent regulatory pathways. Furthermore, we discuss the possibility that different phases of DER activation exist during neuroectodermal patterning with an early phase independent of midline-derived signals.

Glide directs glial fate commitment and cell fate switch between neurones and glia

Development ◽  
1996 ◽  
Vol 122 (1) ◽  
pp. 131-139 ◽  
Author(s):  
S. Vincent ◽  
J.L. Vonesch ◽  
A. Giangrande
Keyword(s):  
Nervous System ◽  
Drosophila Melanogaster ◽  
Peripheral Nervous System ◽  
Glial Cell ◽  
Cell Fate ◽  
Glial Cells ◽  
Neuronal Development ◽  
Precursor Cells ◽  
A Cell ◽  
Glial Fate

Glial cells constitute the second component of the nervous system and are important during neuronal development. In this paper we describe a gene, glial cell deficient, (glide), that is necessary for glial cell fate commitment in Drosophila melanogaster. Mutations at the glide locus prevent glial cell determination in the embryonic central and peripheral nervous system. Moreover, we show that the absence of glial cells is the consequence of a cell fate switch from glia to neurones. This suggests the existence of a multipotent precursor cells in the nervous system. glide mutants also display defects in axonal navigation, which confirms and extends previous results indicating a role for glial cells in these processes.

loco encodes an RGS protein required for Drosophila glial differentiation

Development ◽  
1999 ◽  
Vol 126 (8) ◽  
pp. 1781-1791 ◽  
Author(s):  
S. Granderath ◽  
A. Stollewerk ◽  
S. Greig ◽  
C.S. Goodman ◽  
C.J. O'Kane ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
G Protein ◽  
Glial Cell ◽  
Glial Cells ◽  
Cell Development ◽  
Rgs Proteins ◽  
Glial Differentiation ◽  
G Protein Signalling ◽  
Rgs Domain ◽  
Longitudinal Axon

In Drosophila, glial cell development depends on the gene glial cells missing (gcm). gcm activates the expression of other transcription factors such as pointed and repo, which control subsequent glial differentiation. In order to better understand glial cell differentiation, we have screened for genes whose expression in glial cells depends on the activity of pointed. Using an enhancer trap approach, we have identified loco as such a gene. loco is expressed in most lateral CNS glial cells throughout development. Embryos lacking loco function have an normal overall morphology, but fail to hatch. Ultrastructural analysis of homozygous mutant loco embryos reveals a severe glial cell differentiation defect. Mutant glial cells fail to properly ensheath longitudinal axon tracts and do not form the normal glial-glial cell contacts, resulting in a disruption of the blood-brain barrier. Hypomorphic loco alleles were isolated following an EMS mutagenesis. Rare escapers eclose which show impaired locomotor capabilities. loco encodes the first two known Drosophila members of the family of Regulators of G-protein signalling (RGS) proteins, known to interact with the alpha subunits of G-proteins. loco specifically interacts with the Drosophila alphai-subunit. Strikingly, the interaction is not confined to the RGS domain. This interaction and the coexpression of LOCO and Galphai suggests a function of G-protein signalling for glial cell development.

Gliogenesis inDrosophila: genome-wide analysis of downstream genes ofglial cells missingin the embryonic nervous system

Development ◽  
2002 ◽  
Vol 129 (14) ◽  
pp. 3295-3309 ◽  
Author(s):  
Boris Egger ◽  
Ronny Leemans ◽  
Thomas Loop ◽  
Lars Kammermeier ◽  
Yun Fan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Glial Cell ◽  
Cell Fate ◽  
Glial Cells ◽  
Early Stage ◽  
Genome Wide Analysis ◽  
Glial Development ◽  
Genome Wide

In Drosophila, the glial cells missing (gcm) gene encodes a transcription factor that controls the determination of glial versus neuronal fate. In gcm mutants, presumptive glial cells are transformed into neurons and, conversely, when gcm is ectopically misexpressed, presumptive neurons become glia. Although gcm is thought to initiate glial cell development through its action on downstream genes that execute the glial differentiation program, little is known about the identity of these genes. To identify gcm downstream genes in a comprehensive manner, we used genome-wide oligonucleotide arrays to analyze differential gene expression in wild-type embryos versus embryos in which gcm is misexpressed throughout the neuroectoderm. Transcripts were analyzed at two defined temporal windows during embryogenesis. During the first period of initial gcm action on determination of glial cell precursors, over 400 genes were differentially regulated. Among these are numerous genes that encode other transcription factors, which underscores the master regulatory role of gcm in gliogenesis. During a second later period, when glial cells had already differentiated, over 1200 genes were differentially regulated. Most of these genes, including many genes for chromatin remodeling factors and cell cycle regulators, were not differentially expressed at the early stage, indicating that the genetic control of glial fate determination is largely different from that involved in maintenance of differentiated cells. At both stages, glial-specific genes were upregulated and neuron-specific genes were downregulated, supporting a model whereby gcm promotes glial development by activating glial genes, while simultaneously repressing neuronal genes. In addition, at both stages, numerous genes that were not previously known to be involved in glial development were differentially regulated and, thus, identified as potential new downstream targets of gcm. For a subset of the differentially regulated genes, tissue-specific in vivo expression data were obtained that confirmed the transcript profiling results. This first genome-wide analysis of gene expression events downstream of a key developmental transcription factor presents a novel level of insight into the repertoire of genes that initiate and maintain cell fate choices in CNS development.

Expression of a novel Muller glia specific antigen during development and after optic nerve lesion

Development ◽  
1991 ◽  
Vol 111 (3) ◽  
pp. 789-799 ◽  
Author(s):  
B. Schlosshauer ◽  
D. Grauer ◽  
D. Dutting ◽  
J. Vanselow
Keyword(s):  
Monoclonal Antibodies ◽  
Cell Differentiation ◽  
Optic Nerve ◽  
Glial Cell ◽  
Glial Cells ◽  
Ganglion Cells ◽  
Müller Cell ◽  
Cell Type ◽  
Muller Cell

To generate monoclonal antibodies, immunogen fractions were purified from embryonic chick retinae by temperature-induced detergent-phase separation employing Triton X-114. Under reducing conditions, the monoclonal antibody (mAb) 2M6 identifies a protein doublet at 40 and 46 × 10(3) Mr, which appears to form disulfide-coupled multimers. The 2M6 antigen is regulated developmentally during retinal histogenesis and its expression correlates with Muller glial cell differentiation. Isolated glial endfeet and retinal glial cells in vitro were found to be 2M6-positive, identified with the aid of the general glia marker mAb R5. mAb 2M6 does not bind to any other glial cell type in the CNS as judged from immunohistochemical data. Cell-type specificity was further substantiated by employing retinal explant and single cell cultures on laminin in conjunction with two novel neuron-specific monoclonal antibodies. MAb 2M6 does not bind either to neurites or to neuronal cell bodies. Incubation of retinal cells in vitro with bromodeoxyuridine (BrdU) and subsequent immunodouble labelling with mAb 2M6 and anti-BrdU reveal that mitotic Muller cells can also express the 2M6 antigen. To investigate whether Muller cell differentiation depends on interactions with earlier differentiating ganglion cells, transections of early embryonic optic nerves in vivo were performed. This operation eliminates ganglion cells. Muller cell development and 2M6 antigen expression were not affected, suggesting a ganglion-cell-independent differentiation process. If, however, the optic nerve of juvenile chicken was crushed to induce a transient degeneration/regeneration process in the retina, a significant increase of 2M6 immunoreactivity became evident. These data are in line with the hypothesis that Muller glial cells, in contrast to other distinct glial cell types, might facilitate neural regeneration.

scholarly journals Estrogen receptor β controls proliferation of enteric glia and differentiation of neurons in the myenteric plexus after damage

2018 ◽  
Vol 115 (22) ◽  
pp. 5798-5803 ◽  
Author(s):  
F. D’Errico ◽  
G. Goverse ◽  
Y. Dai ◽  
W. Wu ◽  
M. Stakenborg ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Cell Differentiation ◽  
Glial Cell ◽  
Glial Cells ◽  
Myenteric Plexus ◽  
Neuronal Damage ◽  
Estrogen Receptor Β ◽  
Enteric Glial Cells ◽  
Cell Medium

Injury to the enteric nervous system (ENS) can cause several gastrointestinal (GI) disorders including achalasia, irritable bowel syndrome, and gastroparesis. Recently, a subpopulation of enteric glial cells with neuronal stem/progenitor properties (ENSCs) has been identified in the adult ENS. ENSCs have the ability of reconstituting the enteric neuronal pool after damage of the myenteric plexus. Since the estrogen receptor β (ERβ) is expressed in enteric glial cells and neurons, we investigated whether a selective ERβ agonist, LY3201, can influence neuronal and glial cell differentiation. Myenteric ganglia from the murine muscularis externa were isolated and cultured in either glial cell medium or neuronal medium. In glial cell medium, the number of glial progenitor cells (Sox10+) was increased by fourfold in the presence of LY3201. In the neuronal medium supplemented with an antimitotic agent to block glial cell proliferation, LY3201 elicited a 2.7-fold increase in the number of neurons (neurofilament+ or HuC/D+). In addition, the effect of LY3201 was evaluated in vivo in two murine models of enteric neuronal damage and loss, namely, high-fat diet and topical application of the cationic detergent benzalkonium chloride (BAC) on the intestinal serosa, respectively. In both models, treatment with LY3201 significantly increased the recovery of neurons after damage. Thus, LY3201 was able to stimulate glial-to-neuron cell differentiation in vitro and promoted neurogenesis in the damaged myenteric plexus in vivo. Overall, our study suggests that selective ERβ agonists may represent a therapeutic tool to treat patients suffering from GI disorders, caused by excessive neuronal/glial cell damage.

scholarly journals The Role of MiR-132 in Regulating Neural Stem Cell Proliferation, Differentiation and Neuronal Maturation

2018 ◽  
Vol 47 (6) ◽  
pp. 2319-2330 ◽  
Author(s):  
Dong Chen ◽  
Siyuan Hu ◽  
Zhong Wu ◽  
Jie Liu ◽  
Shaohua Li
Keyword(s):  
Cell Cycle ◽  
Cell Differentiation ◽  
Neurite Outgrowth ◽  
Neuronal Differentiation ◽  
Glial Cell ◽  
Notch Pathway ◽  
Negative Regulator ◽  
Synaptic Proteins ◽  
Neuronal Maturation

Background/Aims: microRNAs are of vital importance in neural development. As a brain-specific miRNA, miR-132 has been well studied in mature neurons. However, its role in neural stem cells (NSCs) remains unclear. In this study, we investigated the role of miR-132 in regulating NSCs proliferation, differentiation and neuronal maturation. Methods: NSCs were obtained from fetal mice spinal cord. Proliferation, cell cycle, cell apoptosis, cell motility were measured through CCK-8, BrdU, AnnexinV-FITC/PI and migration assay respectively. The expression of synaptic proteins and ERK1/2 pathway were detected by western blot. The inactivation of Notch pathway was checked using qPCR. The neurite outgrowth was recorded using Image J software and Neuron J software. Dendritic length was further analyzed through sholl analysis. Fate determination of NSCs, developmental synapse formation was assessed by immunostaining. Results: miR-132 negatively regulated NSCs proliferation by affecting the cell cycle and promoting apoptosis. Inactivated Notch-Hes1pathway was observed in miR-132 overexpression cells. miR-132 was significantly increased in differentiating NSCs following activation of ERK1/2 pathway. miR-132 could impair neuronal differentiation but promote glial cell differentiation by regulating Mecp2 expression. miR-132 was implicated in neurite outgrowth but slightly inhibited postsynaptic PSD-95 expression. The differentiated neurons exhibited normal electrophysiological characteristics, and already interacted with other neurons to form synaptic-like structures. Conclusion: miR-132 was demonstrated as a negative regulator for NSCs self-renewal, neuronal differentiation but promoted glial cell differentiation and neurite outgrowth.

scholarly journals Tcf4 Is Involved in Subset Specification of Mesodiencephalic Dopaminergic Neurons

Biomedicines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 317
Author(s):  
Simone Mesman ◽  
Iris Wever ◽  
Marten P. Smidt
Keyword(s):  
Neuronal Differentiation ◽  
Dopaminergic Neurons ◽  
Neuronal Development ◽  
Neuronal Population ◽  
Minor Role ◽  
Initial Increase ◽  
E Box ◽  
A Minor ◽  
Bhlh Factor

During development, mesodiencephalic dopaminergic (mdDA) neurons form into different molecular subsets. Knowledge of which factors contribute to the specification of these subsets is currently insufficient. In this study, we examined the role of Tcf4, a member of the E-box protein family, in mdDA neuronal development and subset specification. We show that Tcf4 is expressed throughout development, but is no longer detected in adult midbrain. Deletion of Tcf4 results in an initial increase in TH-expressing neurons at E11.5, but this normalizes at later embryonic stages. However, the caudal subset marker Nxph3 and rostral subset marker Ahd2 are affected at E14.5, indicating that Tcf4 is involved in correct differentiation of mdDA neuronal subsets. At P0, expression of these markers partially recovers, whereas expression of Th transcript and TH protein appears to be affected in lateral parts of the mdDA neuronal population. The initial increase in TH-expressing cells and delay in subset specification could be due to the increase in expression of the bHLH factor Ascl1, known for its role in mdDA neuronal differentiation, upon loss of Tcf4. Taken together, our data identified a minor role for Tcf4 in mdDA neuronal development and subset specification.

scholarly journals Neuron–Glia Interactions in Tuberous Sclerosis Complex Affect the Synaptic Balance in 2D and Organoid Cultures

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 134
Author(s):  
Stephanie Dooves ◽  
Arianne J. H. van Velthoven ◽  
Linda G. Suciati ◽  
Vivi M. Heine
Keyword(s):  
Tuberous Sclerosis ◽  
Glial Cells ◽  
Tuberous Sclerosis Complex ◽  
Neuronal Development ◽  
Transmembrane Proteins ◽  
Significant Burden ◽  
Epidermal Growth ◽  
And Control ◽  
Egf Signaling ◽  
The Brain

Tuberous sclerosis complex (TSC) is a genetic disease affecting the brain. Neurological symptoms like epilepsy and neurodevelopmental issues cause a significant burden on patients. Both neurons and glial cells are affected by TSC mutations. Previous studies have shown changes in the excitation/inhibition balance (E/I balance) in TSC. Astrocytes are known to be important for neuronal development, and astrocytic dysfunction can cause changes in the E/I balance. We hypothesized that astrocytes affect the synaptic balance in TSC. TSC patient-derived stem cells were differentiated into astrocytes, which showed increased proliferation compared to control astrocytes. RNA sequencing revealed changes in gene expression, which were related to epidermal growth factor (EGF) signaling and enriched for genes that coded for secreted or transmembrane proteins. Control neurons were cultured in astrocyte-conditioned medium (ACM) of TSC and control astrocytes. After culture in TSC ACM, neurons showed an altered synaptic balance, with an increase in the percentage of VGAT+ synapses. These findings were confirmed in organoids, presenting a spontaneous 3D organization of neurons and glial cells. To conclude, this study shows that TSC astrocytes are affected and secrete factors that alter the synaptic balance. As an altered E/I balance may underlie many of the neurological TSC symptoms, astrocytes may provide new therapeutic targets.

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