scholarly journals Differential Epigenetic Signature of Corticospinal Motor Neurons in ALS

2021 ◽  
Vol 11 (6) ◽  
pp. 754
Author(s):  
Tunch Ozyurt ◽  
Mukesh Gautam
Keyword(s):  
Motor Neurons ◽  
Expression Profiles ◽  
Projection Neurons ◽  
Epigenetic Events ◽  
Underlying Causes ◽  
Excitatory Projection ◽  
Corticospinal Motor Neurons ◽  
Misfolded Sod1 ◽  
End Stage ◽  
Lateral Sclerosis

Corticospinal motor neurons (CSMN) are an indispensable neuron population for the motor neuron circuitry. They are excitatory projection neurons, which collect information from different regions of the brain and transmit it to spinal cord targets, initiating and controlling motor function. CSMN degeneration is pronounced cellular event in motor neurons diseases, such as amyotrophic lateral sclerosis (ALS). Genetic mutations contribute to only about ten percent of ALS. Thus understanding the involvement of other factors, such as epigenetic controls, is immensely valuable. Here, we investigated epigenomic signature of CSMN that become diseased due to misfolded SOD1 toxicity and TDP-43 pathology, by performing quantitative analysis of 5-methylcytosine (5mC) and 5-hydroxymethycytosine (5hmC) expression profiles during end-stage of the disease in hSOD1G93A, and prpTDP-43A315T mice. Our analysis revealed that expression of 5mC was specifically reduced in CSMN of both hSOD1G93A and prpTDP-43A315T mice. However, 5hmC expression was increased in the CSMN that becomes diseased due to misfolded SOD1 and decreased in CSMN that degenerates due to TDP-43 pathology. These results suggest the presence of a distinct difference between different underlying causes. These differential epigenetic events might modulate the expression profiles of select genes, and ultimately contribute to the different paths that lead to CSMN vulnerability in ALS.

scholarly journals Poor Corticospinal Motor Neuron Health Is Associated with Increased Symptom Severity in the Acute Phase Following Repetitive Mild TBI and Predicts Early ALS Onset in Genetically Predisposed Rodents

2021 ◽  
Vol 11 (2) ◽  
pp. 160
Author(s):  
Mor R. Alkaslasi ◽  
Noell E. Cho ◽  
Navpreet K. Dhillon ◽  
Oksana Shelest ◽  
Patricia S. Haro-Lopez ◽  
...  
Keyword(s):  
Risk Factor ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Disease Onset ◽  
Poor Health ◽  
Disease Symptoms ◽  
Established Risk Factor ◽  
Early Injury ◽  
Corticospinal Motor Neurons ◽  
Lateral Sclerosis

Traumatic brain injury (TBI) is a well-established risk factor for several neurodegenerative disorders including Alzheimer’s disease and Parkinson’s disease, however, a link between TBI and amyotrophic lateral sclerosis (ALS) has not been clearly elucidated. Using the SOD1G93A rat model known to recapitulate the human ALS condition, we found that exposure to mild, repetitive TBI lead ALS rats to experience earlier disease onset and shortened survival relative to their sham counterparts. Importantly, increased severity of early injury symptoms prior to the onset of ALS disease symptoms was linked to poor health of corticospinal motor neurons and predicted worsened outcome later in life. Whereas ALS rats with only mild behavioral injury deficits exhibited no observable changes in corticospinal motor neuron health and did not present with early onset or shortened survival, those with more severe injury-related deficits exhibited alterations in corticospinal motor neuron health and presented with significantly earlier onset and shortened lifespan. While these studies do not imply that TBI causes ALS, we provide experimental evidence that head injury is a risk factor for earlier disease onset in a genetically predisposed ALS population and is associated with poor health of corticospinal motor neurons.

scholarly journals Does Sporadic Amyotrophic Lateral Sclerosis Spread via Axonal Connectivities?

2017 ◽  
Vol 01 (03) ◽  
pp. E136-E141 ◽  
Author(s):  
H. Braak ◽  
M. Neumann ◽  
A. Ludolph ◽  
K. Del Tredici
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Motor Neurons ◽  
Pyramidal Cells ◽  
Sporadic Amyotrophic Lateral Sclerosis ◽  
Projection Neurons ◽  
Cortical Projection ◽  
Cytoplasmic Inclusions ◽  
Synaptic Contacts ◽  
Betz Cells ◽  
Lateral Sclerosis

AbstractThe pathological process underlying sporadic amyotrophic lateral sclerosis (sALS) that is associated with the formation of cytoplasmic inclusions of a nuclear protein (TDP-43) is confined to only a few types of long-axoned projection neurons. The giant Betz pyramidal cells of the primary motor neocortex as well as large α-motor neurons of the lower brainstem and spinal cord become involved early. In the human brain, these 2 neuronal types are to a large extent interconnected by monosynaptic axonal projections. The cell nuclei of affected neurons gradually forfeit their normal expression of the protein TDP-43. In α-motor neurons, this nuclear loss is followed by the formation of insoluble TDP-43-immunopositive inclusions in the cytoplasm, whereas in Betz cells the loss of nuclear expression remains for an unknown period of time unaccompanied by somatodendritic and/or axoplasmic aggregations. It is possible that in cortical pyramidal cells (Betz cells) the nuclear clearing initially leads to the formation of an abnormal but still soluble cytoplasmic TDP-43 which may enter the axoplasm and, following transmission via direct synaptic contacts, induces anew TDP-43 dysregulation and aggregation in recipient neurons. The trajectory of the spreading pattern that consecutively develops during the course of sALS is consistent with the dissemination from chiefly cortical projection neurons via axonal transport through direct synaptic contacts leading to the secondary induction of TDP-43-containing inclusions within recipient nerve cells in involved subcortical regions.

scholarly journals Early upregulation of cytosolic phospholipase A2α in motor neurons is induced by misfolded SOD1 in a mouse model of amyotrophic lateral sclerosis

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Yafa Fetfet Malada Edelstein ◽  
Yulia Solomonov ◽  
Nurit Hadad ◽  
Leenor Alfahel ◽  
Adrian Israelson ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Amyotrophic Lateral Sclerosis ◽  
Transgenic Mice ◽  
Motor Neurons ◽  
Dependent Manner ◽  
Mutant Sod1 ◽  
Over Expression ◽  
Cytosolic Phospholipase ◽  
Misfolded Sod1 ◽  
Lateral Sclerosis

Abstract Background Amyotrophic lateral sclerosis (ALS) is a fatal multifactorial neurodegenerative disease characterized by the selective death of motor neurons. Cytosolic phospholipase A2 alpha (cPLA2α) upregulation and activation in the spinal cord of ALS patients has been reported. We have previously shown that cPLA2α upregulation in the spinal cord of mutant SOD1 transgenic mice (SOD1G93A) was detected long before the development of the disease, and inhibition of cPLA2α upregulation delayed the disease’s onset. The aim of the present study was to determine the mechanism for cPLA2α upregulation. Methods Immunofluorescence analysis and western blot analysis of misfolded SOD1, cPLA2α and inflammatory markers were performed in the spinal cord sections of SOD1G93A transgenic mice and in primary motor neurons. Over expression of mutant SOD1 was performed by induction or transfection in primary motor neurons and in differentiated NSC34 motor neuron like cells. Results Misfolded SOD1 was detected in the spinal cord of 3 weeks old mutant SOD1G93A mice before cPLA2α upregulation. Elevated expression of both misfolded SOD1 and cPLA2α was specifically detected in the motor neurons at 6 weeks with a high correlation between them. Elevated TNFα levels were detected in the spinal cord lysates of 6 weeks old mutant SOD1G93A mice. Elevated TNFα was specifically detected in the motor neurons and its expression was highly correlated with cPLA2α expression at 6 weeks. Induction of mutant SOD1 in primary motor neurons induced cPLA2α and TNFα upregulation. Over expression of mutant SOD1 in NSC34 cells caused cPLA2α upregulation which was prevented by antibodies against TNFα. The addition of TNFα to NSC34 cells caused cPLA2α upregulation in a dose dependent manner. Conclusions Motor neurons expressing elevated cPLA2α and TNFα are in an inflammatory state as early as at 6 weeks old mutant SOD1G93A mice long before the development of the disease. Accumulated misfolded SOD1 in the motor neurons induced cPLA2α upregulation via induction of TNFα.

scholarly journals Corticospinal Motor Neurons and Related Subcerebral Projection Neurons Undergo Early and Specific Neurodegeneration in hSOD1G93A Transgenic ALS Mice

2011 ◽  
Vol 31 (11) ◽  
pp. 4166-4177 ◽  
Author(s):  
P. H. Ozdinler ◽  
S. Benn ◽  
T. H. Yamamoto ◽  
M. Guzel ◽  
R. H. Brown ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Projection Neurons ◽  
Corticospinal Motor Neurons

scholarly journals The Novel Regulatory Role of lncRNA-miRNA-mRNA Axis in Amyotrophic Lateral Sclerosis: An Integrated Bioinformatics Analysis

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Dingsheng Liu ◽  
Xiaojia Zuo ◽  
Peng Zhang ◽  
Rui Zhao ◽  
Donglin Lai ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Motor Neurons ◽  
Expression Profiles ◽  
Messenger Rnas ◽  
The Novel ◽  
Protein Protein Interaction ◽  
Cerna Network ◽  
And Control ◽  
Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease that primarily affects motor neurons, causing muscle atrophy, bulbar palsy, and pyramidal tract signs. However, the aetiology and pathogenesis of ALS have not been elucidated to date. In this study, a competitive endogenous RNA (ceRNA) network was constructed by analyzing the expression profiles of messenger RNAs (mRNAs) and long noncoding RNAs (lncRNAs) that were matched by 7 ALS samples and 4 control samples, and then a protein-protein interaction (PPI) network was constructed to identify the genes related to ALS. Gene Ontology (GO) was used to study the potential functions of differentially expressed mRNAs (DEmRNAs) in the ceRNA network. For the ALS and control groups, 247177 potential lncRNA-mRNA ceRNA relationship pairs were screened. Analysis of significant relationship pairs demonstrated that the PPI modules formed by the MALAT1-regulated SYNRG, ITSN2, PICALM, AP3B1, and AAK1 genes may play important roles in the pathogenesis of ALS, and these results may help to characterize the pathogenesis of ALS.

scholarly journals Misfolded SOD1 inclusions in patients with mutations in C9orf72 and other ALS/FTD-associated genes

2019 ◽  
Vol 90 (8) ◽  
pp. 861-869 ◽  
Author(s):  
Karin Forsberg ◽  
Karin Graffmo ◽  
Bente Pakkenberg ◽  
Markus Weber ◽  
Martin Nielsen ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Superoxide Dismutase 1 ◽  
Wild Type ◽  
Spinal Motor Neurons ◽  
Hexanucleotide Repeat ◽  
Cortical Motor ◽  
Spinal Motor ◽  
Repeat Expansions ◽  
Misfolded Sod1 ◽  
Lateral Sclerosis

ObjectiveA hallmark of amyotrophic lateral sclerosis (ALS) caused by mutations in superoxide dismutase-1 (SOD1) are inclusions containing SOD1 in motor neurons. Here, we searched for SOD1-positive inclusions in 29 patients carrying ALS-linked mutations in six other genes.MethodsA panel of antibodies that specifically recognise misfolded SOD1 species were used for immunohistochemical investigations of autopsy tissue.ResultsThe 18 patients with hexanucleotide-repeat-expansions in C9orf72 had inclusions of misfolded wild type (WT) SOD1WT in spinal motor neurons. Similar inclusions were occasionally observed in medulla oblongata and in the motor cortex and frontal lobe. Patients with mutations in FUS, KIF5A, NEK1, ALSIN or VAPB, carried similar SOD1WT inclusions. Minute amounts of misSOD1WT inclusions were detected in 2 of 20 patients deceased from non-neurological causes and in 4 of 10 patients with other neurodegenerative diseases. Comparison was made with 17 patients with 9 different SOD1 mutations. Morphologically, the inclusions in patients with mutations in C9orf72HRE, FUS, KIF5A, NEK1, VAPB and ALSIN resembled inclusions in patients carrying the wildtype-like SOD1D90A mutation, whereas patients carrying unstable SOD1 mutations (A4V, V5M, D76Y, D83G, D101G, G114A, G127X, L144F) had larger skein-like SOD1-positive inclusions.Conclusions and relevanceAbundant inclusions containing misfolded SOD1WT are found in spinal and cortical motor neurons in patients carrying mutations in six ALS-causing genes other than SOD1. This suggests that misfolding of SOD1WT can be part of a common downstream event that may be pathogenic. The new anti-SOD1 therapeutics in development may have applications for a broader range of patients.

scholarly journals Neuroinflammation as the Proximate Cause of Signature Pathogenic Pattern Progression in Amyotrophic Lateral Sclerosis, Aids, and Multiple Sclerosis

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Lawrence M. Agius
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Motor Neurons ◽  
Oxidative Degradation ◽  
Proximate Cause ◽  
Cell Components ◽  
Large Motor ◽  
The One ◽  
Definition Of ◽  
End Stage ◽  
Lateral Sclerosis

The realization of injury to large motor neurons is embedded within contextual reference to the parallel pathways of apoptosis and necrosis of system-patterned evolution. A widespread loss of cell components occurs intracellularly and involves a reactive participation to a neuroinflammation that potentially is immunologically definable. In such terms, sporadic and hereditary forms of amyotrophic sclerosis are paralleled by the components of a reactive nature that involve the aggregation of proteins and conformational misfolding on the one hand and a powerful oxidative degradation that overwhelms the proteasome clearance mechanisms. In such terms, global participation is only one aspect of a disorder realization that induces the development of the defining systems of modulation and of injury that involves the systems of consequence as demonstrated by the overwhelming immaturity of the molecular variants of mutated superoxide dismutase. It is further to such processes of neuroinflammatory consequence that the immune system is integral to the reactive involvement of neurons as patterns of disease recognition and as the system biology of prevalent voluntarily motor character. It is highly significant to recognize various inflammatory states in the nervous system as prototype variability in phenotype expression and as incremental progression in pathogenesis. In fact a determining definition of amyotrophic lateral sclerosis is an incremental phenotype modulation within the pathways of the consequential loss and depletion of motor cell components in the first instance. Neuroinflammation proves a pattern of the contextual spread of such pathogenic progression in the realization of end-stage injury states involving neurons and neuronal networks.

scholarly journals Microglial transcriptome analysis in the rNLS8 mouse model of TDP-43 proteinopathy reveals discrete expression profiles associated with neurodegenerative progression and recovery

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Mandana Hunter ◽  
Krista J. Spiller ◽  
Myrna A. Dominique ◽  
Hong Xu ◽  
Francis W. Hunter ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Disease Progression ◽  
Differentially Expressed Genes ◽  
Motor Neurons ◽  
Expression Profiles ◽  
Disease Onset ◽  
Gene Expression Profiles ◽  
Differentially Expressed ◽  
Transcriptomic Changes ◽  
Lateral Sclerosis

AbstractThe microglial reaction is a hallmark of neurodegenerative conditions, and elements thereof may exert differential effects on disease progression, either worsening or ameliorating severity. In amyotrophic lateral sclerosis (ALS), a syndrome characterized by cytoplasmic aggregation of TDP-43 protein and atrophy of motor neurons in the cortex and spinal cord, the transcriptomic signatures of microglia during disease progression are incompletely understood. Here, we performed longitudinal RNAseq analysis of cortical and spinal cord microglia from rNLS8 mice, in which doxycycline-regulatable expression of human TDP-43 (hTDP-43) in the cytoplasm of neurons recapitulates many features of ALS. Transgene suppression in rNLS8 mice leads to functional, anatomical and electrophysiological resolution that is dependent on a microglial reaction that is concurrent with recovery rather than disease onset. We identified basal differences between the gene expression profiles of microglia dependent on localization in spinal cord or cortex. Microglia subjected to chronic hTDP-43 overexpression demonstrated transcriptomic changes in both locations. We noted strong upregulation of Apoe, Axl, Cd63, Clec7a, Csf1, Cst7, Igf1, Itgax, Lgals3, Lilrb4, Lpl and Spp1 during late disease and recovery. Importantly, we identified a distinct suite of differentially expressed genes associated with each phase of disease progression and recovery. Differentially expressed genes were associated with chemotaxis, phagocytosis, inflammation, and production of neuroprotective factors. These data provide new insights into the microglial reaction in TDP-43 proteinopathy. Genes differentially expressed during progression and recovery may provide insight into a unique instance in which the microglial reaction promotes functional recovery after neuronal insult.

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