Gene expression of NMDA and AMPA receptors in different facial motor neurons

Abstract Background Left-right asymmetries are a common feature of metazoans and can be found in a number of organs including the nervous system. These asymmetries are particularly pronounced in the simple central nervous system (CNS) of the swimming tadpole larva of the tunicate Ciona, which displays a chordate ground plan. While common pathway elements for specifying the left/right axis are found among chordates, particularly a requirement for Nodal signaling, Ciona differs temporally from its vertebrate cousins by specifying its axis at the neurula stage, rather than at gastrula. Additionally, Ciona and other ascidians require an intact chorionic membrane for proper left-right specification. Whether such differences underlie distinct specification mechanisms between tunicates and vertebrates will require broad understanding of their influence on CNS formation. Here, we explore the consequences of disrupting left-right axis specification on Ciona larval CNS cellular anatomy, gene expression, synaptic connectivity, and behavior. Results We show that left-right asymmetry disruptions caused by removal of the chorion (dechorionation) are highly variable and present throughout the Ciona larval nervous system. While previous studies have documented disruptions to the conspicuously asymmetric sensory systems in the anterior brain vesicle, we document asymmetries in seemingly symmetric structures such as the posterior brain vesicle and motor ganglion. Moreover, defects caused by dechorionation include misplaced or absent neuron classes, loss of asymmetric gene expression, aberrant synaptic projections, and abnormal behaviors. In the motor ganglion, a brain structure that has been equated with the vertebrate hindbrain, we find that despite the apparent left-right symmetric distribution of interneurons and motor neurons, AMPA receptors are expressed exclusively on the left side, which equates with asymmetric swimming behaviors. We also find that within a population of dechorionated larvae, there is a small percentage with apparently normal left-right specification and approximately equal population with inverted (mirror-image) asymmetry. We present a method based on a behavioral assay for isolating these larvae. When these two classes of larvae (normal and inverted) are assessed in a light dimming assay, they display mirror-image behaviors, with normal larvae responding with counterclockwise swims, while inverted larvae respond with clockwise swims. Conclusions Our findings highlight the importance of left-right specification pathways not only for proper CNS anatomy, but also for correct synaptic connectivity and behavior.

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Co-Culture of ES Cell-Derived Motor Neurons and Myotubes Show the Formation of Neuromuscular Junctions and Changes in Gene Expression

Journal of Reconstructive Microsurgery ◽

10.1055/s-2006-949682 ◽

2006 ◽

Vol 22 (06) ◽

Author(s):

Aleid Ruijs ◽

Tateki Kubo ◽

Jae Song ◽

Milan Ranka ◽

Mark Randolph ◽

...

Keyword(s):

Gene Expression ◽

Motor Neurons ◽

Neuromuscular Junctions ◽

Es Cell

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Xrp1 genetically interacts with the ALS-associated FUS orthologue caz and mediates its toxicity

The Journal of Cell Biology ◽

10.1083/jcb.201802151 ◽

2018 ◽

Vol 217 (11) ◽

pp. 3947-3964 ◽

Cited By ~ 7

Author(s):

Moushami Mallik ◽

Marica Catinozzi ◽

Clemens B. Hug ◽

Li Zhang ◽

Marina Wagner ◽

...

Keyword(s):

Gene Expression ◽

Life Span ◽

Motor Neurons ◽

Gene Expression Regulation ◽

Genetic Interaction ◽

Motor Deficits ◽

Chromatin Binding ◽

Mutant Phenotypes ◽

Gene Expression Dysregulation ◽

Lateral Sclerosis

Cabeza (caz) is the single Drosophila melanogaster orthologue of the human FET proteins FUS, TAF15, and EWSR1, which have been implicated in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. In this study, we identified Xrp1, a nuclear chromatin-binding protein, as a key modifier of caz mutant phenotypes. Xrp1 expression was strongly up-regulated in caz mutants, and Xrp1 heterozygosity rescued their motor defects and life span. Interestingly, selective neuronal Xrp1 knockdown was sufficient to rescue, and neuronal Xrp1 overexpression phenocopied caz mutant phenotypes. The caz/Xrp1 genetic interaction depended on the functionality of the AT-hook DNA-binding domain in Xrp1, and the majority of Xrp1-interacting proteins are involved in gene expression regulation. Consistently, caz mutants displayed gene expression dysregulation, which was mitigated by Xrp1 heterozygosity. Finally, Xrp1 knockdown substantially rescued the motor deficits and life span of flies expressing ALS mutant FUS in motor neurons, implicating gene expression dysregulation in ALS-FUS pathogenesis.

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Mouse embryonic stem cells can differentiate via multiple paths to the same state

eLife ◽

10.7554/elife.26945 ◽

2017 ◽

Vol 6 ◽

Cited By ~ 31

Author(s):

James Alexander Briggs ◽

Victor C Li ◽

Seungkyu Lee ◽

Clifford J Woolf ◽

Allon Klein ◽

...

Keyword(s):

Gene Expression ◽

Motor Neuron ◽

Motor Neurons ◽

Embryonic Stem ◽

The Novel ◽

Transitional State ◽

Single Cell Rna Sequencing ◽

Intermediate States ◽

Multiple Paths ◽

Alternative Routes

In embryonic development, cells differentiate through stereotypical sequences of intermediate states to generate particular mature fates. By contrast, driving differentiation by ectopically expressing terminal transcription factors (direct programming) can generate similar fates by alternative routes. How differentiation in direct programming relates to embryonic differentiation is unclear. We applied single-cell RNA sequencing to compare two motor neuron differentiation protocols: a standard protocol approximating the embryonic lineage, and a direct programming method. Both initially undergo similar early neural commitment. Later, the direct programming path diverges into a novel transitional state rather than following the expected embryonic spinal intermediates. The novel state in direct programming has specific and uncharacteristic gene expression. It forms a loop in gene expression space that converges separately onto the same final motor neuron state as the standard path. Despite their different developmental histories, motor neurons from both protocols structurally, functionally, and transcriptionally resemble motor neurons isolated from embryos.

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Single cell transcriptome profiling of the human developing spinal cord reveals a conserved genetic programme with human specific features

10.1101/2021.04.12.439474 ◽

2021 ◽

Author(s):

Teresa Rayon ◽

Rory J. Maizels ◽

Christopher Barrington ◽

James Briscoe

Keyword(s):

Gene Expression ◽

Spinal Cord ◽

Single Cell ◽

Motor Neurons ◽

Neural Tube ◽

Transcriptome Profiling ◽

Cell Types ◽

Human Embryos ◽

Neuronal Populations ◽

Cell Transcriptome

AbstractThe spinal cord receives input from peripheral sensory neurons and controls motor output by regulating muscle innervating motor neurons. These functions are carried out by neural circuits comprising molecularly and physiologically distinct neuronal subtypes that are generated in a characteristic spatial-temporal arrangement from progenitors in the embryonic neural tube. The systematic mapping of gene expression in mouse embryos has provided insight into the diversity and complexity of cells in the neural tube. For human embryos, however, less information has been available. To address this, we used single cell mRNA sequencing to profile cervical and thoracic regions in four human embryos of Carnegie Stages (CS) CS12, CS14, CS17 and CS19 from Gestational Weeks (W) 4-7. In total we recovered the transcriptomes of 71,219 cells. Analysis of progenitor and neuronal populations from the neural tube, as well as cells of the peripheral nervous system, in dorsal root ganglia adjacent to the neural tube, identified dozens of distinct cell types and facilitated the reconstruction of the differentiation pathways of specific neuronal subtypes. Comparison with existing mouse datasets revealed the overall similarity of mouse and human neural tube development while highlighting specific features that differed between species. These data provide a catalogue of gene expression and cell type identity in the developing neural tube that will support future studies of sensory and motor control systems and can be explored at https://shiny.crick.ac.uk/scviewer/neuraltube/.

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A Study of Gene Expression Changes in Human Spinal and Oculomotor Neurons; Identifying Potential Links to Sporadic ALS

Genes ◽

10.3390/genes11040448 ◽

2020 ◽

Vol 11 (4) ◽

pp. 448

Author(s):

Aayan N. Patel ◽

Dennis Mathew

Keyword(s):

Gene Expression ◽

Disease Progression ◽

Motor Neurons ◽

Expression Profiles ◽

Gene Expression Profiles ◽

Tissue Samples ◽

Disease Symptoms ◽

Sporadic Als ◽

Oculomotor Neurons ◽

Als Patients

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease that causes compromised function of motor neurons and neuronal death. However, oculomotor neurons are largely spared from disease symptoms. The underlying causes for sporadic ALS as well as for the resistance of oculomotor neurons to disease symptoms remain poorly understood. In this bioinformatic-analysis, we compared the gene expression profiles of spinal and oculomotor tissue samples from control individuals and sporadic ALS patients. We show that the genes GAD2 and GABRE (involved in GABA signaling), and CALB1 (involved in intracellular Ca2+ ion buffering) are downregulated in the spinal tissues of ALS patients, but their endogenous levels are higher in oculomotor tissues relative to the spinal tissues. Our results suggest that the downregulation of these genes and processes in spinal tissues are related to sporadic ALS disease progression and their upregulation in oculomotor neurons confer upon them resistance to ALS symptoms. These results build upon prevailing models of excitotoxicity that are relevant to sporadic ALS disease progression and point out unique opportunities for better understanding the progression of neurodegenerative properties associated with sporadic ALS.

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Glutamate AMPA receptors change in motor neurons of SOD1G93A transgenic mice and their inhibition by a noncompetitive antagonist ameliorates the progression of amytrophic lateral sclerosis-like disease

Journal of Neuroscience Research ◽

10.1002/jnr.20715 ◽

2006 ◽

Vol 83 (1) ◽

pp. 134-146 ◽

Cited By ~ 69

Author(s):

Massimo Tortarolo ◽

Giuliano Grignaschi ◽

Novella Calvaresi ◽

Eleonora Zennaro ◽

Gabriella Spaltro ◽

...

Keyword(s):

Transgenic Mice ◽

Motor Neurons ◽

Ampa Receptors ◽

Lateral Sclerosis

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Mouse embryonic stem cells can differentiate via multiple paths to the same state

10.1101/124594 ◽

2017 ◽

Cited By ~ 1

Author(s):

James A. Briggs ◽

Victor C. Li ◽

Seungkyu Lee ◽

Clifford J. Woolf ◽

Allon M. Klein ◽

...

Keyword(s):

Gene Expression ◽

Motor Neuron ◽

Motor Neurons ◽

Embryonic Stem ◽

State Transitions ◽

Standard Protocol ◽

Transitional State ◽

Single Cell Rna Sequencing ◽

Multiple Paths ◽

Alternative Routes

AbstractIn embryonic development, cells must differentiate through stereotypical sequences of intermediate states to generate mature states of a particular fate. By contrast, direct programming can generate similar fates through alternative routes, by directly expressing terminal transcription factors. Yet the cell state transitions defining these new routes are unclear. We applied single-cell RNA sequencing to compare two mouse motor neuron differentiation protocols: a standard protocol approximating the embryonic lineage, and a direct programming method. Both undergo similar early neural commitment. Then, rather than transitioning through spinal intermediates like the standard protocol, the direct programming path diverges into a novel transitional state. This state has specific and abnormal gene expression. It opens a ‘loop’ or ‘worm hole’ in gene expression that converges separately onto the final motor neuron state of the standard path. Despite their different developmental histories, motor neurons from both protocols structurally, functionally, and transcriptionally resemble motor neurons from embryos.

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Testing of the therapeutic efficacy and safety of AMPA receptor RNA aptamers in an ALS mouse model

Life Science Alliance ◽

10.26508/lsa.202101193 ◽

2022 ◽

Vol 5 (4) ◽

pp. e202101193

Author(s):

Megumi Akamatsu ◽

Takenari Yamashita ◽

Sayaka Teramoto ◽

Zhen Huang ◽

Janet Lynch ◽

...

Keyword(s):

Ampa Receptor ◽

Motor Neurons ◽

Ampa Receptors ◽

Motor Dysfunction ◽

Rna Aptamers ◽

Sporadic Amyotrophic Lateral Sclerosis ◽

Efficacy And Safety ◽

Intracerebroventricular Infusion ◽

Sporadic Als ◽

Als Patients

In motor neurons of sporadic amyotrophic lateral sclerosis (ALS) patients, the RNA editing at the glutamine/arginine site of the GluA2 subunit of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors is defective or incomplete. As a result, AMPA receptors containing the abnormally expressed, unedited isoform of GluA2 are highly Ca2+-permeable, and are responsible for mediating abnormal Ca2+ influx, thereby triggering motor neuron degeneration and cell death. Thus, blocking the AMPA receptor–mediated, abnormal Ca2+ influx is a potential therapeutic strategy for treatment of sporadic ALS. Here, we report a study of the efficacy and safety of two RNA aptamers targeting AMPA receptors on the ALS phenotype of AR2 mice. A 12-wk continuous, intracerebroventricular infusion of aptamers to AR2 mice reduced the progression of motor dysfunction, normalized TDP-43 mislocalization, and prevented death of motor neurons. Our results demonstrate that the use of AMPA receptor aptamers as a novel class of AMPA receptor antagonists is a promising strategy for developing an ALS treatment approach.

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Differential CTCF binding in motor neurons and lymphocytes

10.1101/2021.03.19.435989 ◽

2021 ◽

Author(s):

Belkis Atasever Arslan ◽

Scott T. Brady ◽

Gamze Gunal Sadik

Keyword(s):

Gene Expression ◽

Progenitor Cells ◽

Motor Neurons ◽

Neurological Disorders ◽

Neural Progenitor Cells ◽

Developmental Stages ◽

Neural Progenitor ◽

Ctcf Binding ◽

Ctcf Binding Site ◽

Expression Levels

Transcriptional regulation of protein-coding genes is a primary control mechanism of cellular function. Similarities in regulation of expression for select genes between lymphocytes and neurons have led to proposals that such genes may be useful biomarkers for some neurological disorders that can be monitored via patient lymphocyte populations. Examination of shared molecular mechanisms underlying neurogenesis and lymphocyte differentiation may give help to identify relevant pathways and suggest additional biomarkers in lymphocytes that are relevant to neurological disorders. In this study, we analysed similarities and conserved regions in several genes regulated by CCCTC-binding factor (CTCF) during lymphocyte and neuronal developmental stages. We performed epigenetic analysis of CTCF binding Trak1, Gabpa, Gabpb1, Gabpb2, Gfi1, Gfi1b gene loci at T and B lymphocytes at different developmental stages, as well as in neural progenitor cells and motor neurons. Common and shared CTCF binding events at Trak1 gene suggest additional transcriptional regulatory factors that control Trak1 gene expression levels differ in neurons and lymphocytes. Gabpb1 gene includes a common CTCF binding site shared with neurons and lymphocytes. Correlation of CTCF binding analysis and gene expression profile suggests that CTCF binding plays a role in epigenetic regulation of Gabpb1 gene. In contrast, while Gfi1a gene is phylogenetically well-conserved and CTCF sites are occupied in lymphocytes, there are no CTCF binding occupied in neurons and neural progenitor cells. Low expression levels of Gfi1s in neurons indicate that regulation of this gene is CTCF-independent in neurons. Although Gfi1b is highly homologous to Gfi1, differences in expression levels suggest that Gfi1b is critical for both lymphogenesis and neurogenesis. Neurons and lymphocytes have multiple common CTCF binding sites in the Gfi1b gene, although lineage specific transcriptional regulators that play a role in their different expression levels still need to be identified. The partial overlap in CTCF regulatory sites for some genes in neurons and lymphocytes suggest that there may be markers that can exhibit parallel changes in these cells and serve as biomarkers.

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