Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Ribosome profiling of SMN-primed ribosomes and active ribosome profiling from brains of a mouse model of severe SMA

ABSTRACT: Spinal muscular atrophy (SMA) is the most common genetic cause of infant mortality, with an incidence of around 1 in 6,000-10,000 live births. SMA is caused by low levels of full-length survival of motor neuron protein (SMN). We demonstrate that SMN binds to ribosomes and that this interaction is tissue-dependent. We performed ribosome profiling analyses on lysates from P5 wild-type mouse brains exposed to RNase I, from which we isolated SMN-primed ribosomes by immunoprecipitation. SMN-primed ribosomes are preferentially positioned within the first five codons of a set of mRNAs which are enriched for translational enhancer sequences in the 5’UTR and rare codons at the beginning of their coding sequence. These SMN-specific mRNAs are associated with neurogenesis, lipid metabolism, ubiquitination, chromatin regulation and translation. Additionally, we analyzed the positioning of active ribosomes using the Active-RiboSeq method based on RiboLace and compared early symptomatic SMA mouse brains to age-matched controls. We found that loss of SMN induces ribosome depletion, especially at the beginning of the coding sequence of SMN-specific mRNAs, leading to impairment of proteins involved in motor neuron function and stability. Keywords: motor neuron disease, spinal muscular atrophy, SMA, SMN, SMN1, survival of motor neuron, SMN-primed ribosome profiling, translation, RiboLace, Ribo-Seq, active translation, ribosome heterogeneity

ORGANISM(S): Mus musculus

PROVIDER: GSE154106 | GEO | 2020/08/11

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

Gene expression profiling of LMC and MMC motor neurons in SMA mice

Project description:Spinal muscular atrophy (SMA) is a neurodegenerative disease which exhibits selective motor neuron death caused by a ubiquitous deficiency of the survival motor neuron (SMN) protein. It remains unclear how the ubiquitous reduction of SMN lead to death in selective motor neuron pools. Medial motor neuron columns (MMC) are vulnerable, whereas lateral motor columns (LMC) are resistant to motor neuron death in SMA. Here we performed microarray and pathway analysis comparing cholera toxin subunit B (CTb) labeled vulnerable MMC and resistant LMC of pre-symptomatic SMA with corresponding motor neuron columns of control mice to identify pathways involved in selective motor neuron death in SMA. WT is FVB. SMN is Delta7 (SMNΔ7;SMN2;Smn-) on a FVB background.

2017-12-12 | GSE81245 | GEO

The small-molecule flunarizine in spinal muscular atrophy patient fibroblasts impacts on the Gemin components of the SMN complex and RNA-binding proteins relevant to motor neuron diseases

Project description:The deficiency of Survival motor neuron (SMN) protein causes the motor neuron disease spinal muscular atrophy (SMA). One of the cellular hallmarks of motor neuron diseases is the reduction in number of nuclear bodies (NBs) positive for the SMN protein. Owing to its ubiquitous expression, the consequences of SMN reduction can be studied in SMA patient fibroblasts. In previous studies, we described the beneficial effects of flunarizine on SMN-positive NBs both in fibroblasts of SMA patients and in spinal motor neurons of an SMA mouse model. Given that nuclear bodies are involved in RNA metabolism, here the goals are to make a proof-of-concept that genes modulated by flunarizine at the RNA levels can be identified and confirmed at the protein levels in SMA patient fibroblasts. Indeed, RNA-Seq analysis reveals that TXNIP is the most reduced by a 4-hr flunarizine treatment of SMA patient fibroblasts. This result is confirmed by RT-qPCR. Moreover, immunoblot analyses also shows a marked reduction of TXNIP at the protein levels in flunarizine-treated SMA fibroblasts.

2020-04-30 | GSE145146 | GEO

Gain of toxic function by long-term SMN overexpression in the sensory-motor circuit.

Project description:The neurodegenerative disease spinal muscular atrophy (SMA) is a leading genetic cause of infant death caused by deficiency in the survival motor neuron (SMN) protein. Currently approved SMA treatments aim to restore SMN, but the potential for expression of SMN beyond physiological levels is a unique feature of AAV9-SMN gene therapy. Here, we show that long-term AAV9-mediated SMN overexpression in mouse models induces dose-dependent, late-onset motor dysfunction associated with loss of proprioceptive synapses and neurodegeneration. Mechanistically, aggregation of overexpressed SMN in the cytoplasm of motor circuit neurons sequesters components of small nuclear ribonucleoproteins (snRNPs), leading to splicing dysregulation and widespread transcriptome abnormalities with prominent signatures of neuroinflammation and innate immune response. Thus, long-term SMN overexpression can interfere with its normal activity in RNA regulation and trigger SMA-like pathogenic events through toxic gain of function mechanisms. These unanticipated, SMN-dependent and neuron-specific liabilities of AAV9-SMN warrant further evaluation of the long-term safety of gene therapy in SMA.

2021-02-01 | GSE149391 | GEO

The Bap1-SMN axis in Dpp4+ skeletal muscle mesenchymal cells regulates survival of motor neurons

Project description:Spinal muscular atrophy (SMA) is a neuromuscular disease caused by mutations in the survival of motor neuron (SMN) gene. Although the primary manifestation of SMA is degeneration of motor neurons in a dying-back manner, deficient SMN intrinsic to motor neurons does not cause severe motor neuron loss, as is the case in SMA mouse models. Thus, the involvement of non-neuronal cells in the pathogenesis of SMA has been suggested. Here, we report that a novel subset of fibro-adipogenic progenitors expressing Dpp4 (Dpp4+ FAPs) is required for the survival of motor neurons, in which BRCA1-associating protein 1 (Bap1) is crucial for the stabilization of SMN by preventing its ubiquitination-dependent degradation. Inactivation of Bap1 in FAPs decreased SMN levels and accompanied degeneration of the neuromuscular junction, leading to dying-back loss of motor neurons and muscle atrophy, reminiscent of SMA pathogenesis. Overexpression of ubiquitination-resistant SMN variant, SMNK186R, in Bap1-null FAPs completely prevented neuromuscular degenerations. In addition, transplantation of Dpp4+ FAPs, but not Dpp4- FAPs, completely rescued neuromuscular defects in the mutant mice. Our data revealed that Bap1-mediated stabilization of SMN in Dpp4+ FAPs is crucial for the survival of motor neurons and provided a new therapeutic approach to treat SMA.

2022-06-30 | GSE190426 | GEO

Transcriptome and translatome profiling from brains of a mouse model of severe SMA

Project description:Spinal muscular atrophy (SMA) is the most common genetic cause of infant mortality, with an incidence of around 1 in 6,000-10,000 live births. SMA is caused by low levels of full-length survival of motor neuron protein (SMN). Approximately 95% of SMA cases in humans are caused by homozygous deletion of SMN1, with a smaller number caused by discrete mutations within the gene. In concert with other RNA binding proteins, SMN forms complexes both in the nucleus and the cytoplasm of neurons. As such, SMN protein has housekeeping roles in the assembly of ribonucleoprotein (RNP) complexes. In addition, SMN localises to dendrites, synapses and axons in vivo and in vitro, where it is part of messenger RNP (mRNP) complexes with well-known roles in the transport of mRNA. These cellular processes are tightly linked to local translation, suggesting that SMN may play a pivotal role in its regulation. We employed next generation sequencing (NGS) to identify and quantify RNAs associated with polysomes (POL-Seq) in parallel with total cytoplasmic RNA (RNA-Seq) in an established mouse model of severe SMA at both early and late-symptomatic stages. This approach enables the simultaneous identification of variations in RNA populations at both translatome (RNAs engagement with polysomes) and transcriptome (steady state cytoplasmic RNAs) levels. Keywords: motor neuron disease, spinal muscular atrophy, SMA,SMN, translation, polysome profiling, POL-Seq, RNA-Seq

2017-10-24 | GSE102204 | GEO

SMN deficiency perturbs monoamine neurotransmitter metabolism in spinal muscular atrophy

Project description:<p>Beyond motor neuron degeneration, homozygous mutations in the survival motor neuron 1 (SMN1) gene cause multiorgan and metabolic defects in patients with spinal muscular atrophy (SMA). However, the precise biochemical features of these alterations and the age of onset in the brain and peripheral organs remain unclear. Using untargeted NMR-based metabolomics in SMA mice, we identify cerebral and hepatic abnormalities related to energy homeostasis pathways and amino acid metabolism, emerging already at postnatal day 3 (P3) in the liver. Through HPLC, we find that SMN deficiency induces a drop in cerebral norepinephrine levels in overt symptomatic SMA mice at P11, affecting the mRNA and protein expression of key genes regulating monoamine metabolism, including aromatic L-amino acid decarboxylase (AADC), dopamine beta-hydroxylase (DβH) and monoamine oxidase A (MAO-A). In support of the translational value of our preclinical observations, we also discovered that SMN upregulation increases cerebrospinal fluid norepinephrine concentration in Nusinersen-treated SMA1 patients. Our findings highlight a previously unrecognized harmful influence of low SMN levels on the expression of critical enzymes involved in monoamine metabolism, suggesting that SMN-inducing therapies may modulate catecholamine neurotransmission. These results may also be relevant for setting therapeutic approaches to counteract peripheral metabolic defects in SMA. </p>

2023-11-27 | MTBLS8784 | MetaboLights

Trancriptional regulation by axonal SMN on motor neuron cells

Project description:Muscular atrophy (SMA) is an autosomal recessive disease causing selective motor neuron death by the loss of telomeric survival motor neuron gene, SMN1. Axonal SMN, a-SMN, is a truncated form of SMN, derived from an alternatively spliced SMN1 gene. (Setola, et. al. 2007 PNAS 104, 1959-1964). The cellular clones expressing a-SMN in a tetracycline-dependent manner were isolated from NSC34 by two-step stable transfection, first with the tetracycline-repressor construct and subsequently with the a-SMN cDNA. To identify novel a-SMN target genes, the transcriptome of several a-SMN clones was analyzed and compared with that of parental cells.

2012-01-07 | E-MEXP-3402 | biostudies-arrayexpress

Transcriptome profiling of severe spinal muscular atrophy mouse embryonic stem cell-derived motor neurons

Project description:Proximal spinal muscular atrophy (SMA) is an early onset, autosomal recessive motor neuron disease caused by loss of or mutation in SMN1 (survival motor neuron 1). Despite understanding the genetic basis underlying this disease, it is still not known why motor neurons (MNs) are selectively affected by the loss of the ubiquitously expressed SMN protein. Using a mouse embryonic stem cell (mESC) model for severe SMA, the RNA transcript profiles (transcriptomes) between control and severe SMA (SMN2+/+;mSmn-/-) mESC-derived MNs were compared in this study using massively parallel RNA sequencing (RNA-Seq). The MN differentiation efficiencies between control and severe SMA mESCs were similar. RNA-Seq analysis identified 3094 upregulated and 6964 downregulated transcripts in SMA mESC-derived MNs when compared against control cells. Pathway and network analysis of the differentially expressed RNA transcripts showed that pluripotency and cell proliferation transcripts were significantly increased in SMA MNs while transcripts related to neuronal development and activity were reduced. The differential expression of selected transcripts such as Crabp1, Crabp2 and Nkx2.2 was validated in a second mESC model for SMA as well as in the spinal cords of low copy SMN2 severe SMA mice. Furthermore, the levels of these selected transcripts were restored in high copy SMN2 rescue mouse spinal cords when compared against low copy SMN2 severe SMA mice. These findings suggest that SMN deficiency affects processes critical for normal development and maintenance of MNs. RNA profiles were generated from FACS-purified control and SMA mESC-derived motor neurons (n=3/genotype) by deep sequencing using Illumina HighSeq 2500

2014-09-08 | E-GEOD-56284 | biostudies-arrayexpress

Suppression of NCALD protects against spinal muscular atrophy by restoring impaired endocytosis

Project description:Spinal muscular atrophy (SMA) is a common genetic motor neuron (MN) disease caused by low levels of the ubiquitously expressed housekeeping survival motor neuron (SMN) protein, whereas concomitant overexpression of plastin 3 (PLS3) protects from SMA. Here we identify neurocalcin delta (NCALD), a neuronal calcium sensor, as a second fully protective SMA modifier, which counteracts SMA pathology when downregulated. We show reduced Ca2+ influx and impaired endocytosis in SMA, which are crucial processes in synaptic vesicle recycling and neurotransmission. Remarkably, both reduced NCALD or increased PLS3 restore endocytosis in cell culture and MN function across species in zebrafish, worm and mouse SMA models, whereas Ca2+ influx remains disturbed. Furthermore, NCALD physically binds clathrin in a Ca2+-dependent manner. We propose that NCALD acts as a Ca2+-regulated inhibitor of endocytosis, and that endocytosis is critically affected in SMA. This finding opens new therapeutic avenues for SMA. Multifactorial design comparing affected patients and unaffected disease carriers against severly affected control group to identify disease modifying transcripts

2015-01-01 | E-GEOD-58316 | biostudies-arrayexpress

Spinal Muscular Atrophy Patient iPSC-derived Motor Neurons Display Altered Proteins at Early Stages of Differentiation

Project description:Spinal muscular atrophy (SMA) is characterized by low levels of survival motor neuron (SMN) protein and loss of motor neurons (MN); however, the underlying mechanism that links SMN deficiency to selective motor neuronal dysfunction is still largely unknown. We present here, for the first time, a comprehensive quantitative mass spectrometry study that covers the development of iPSC-derived MNs from both healthy individuals and SMA patients. We show an altered proteomic signature in SMA already at early stages during MN differentiation, associated with ER to Golgi transport, mRNA splicing and protein ubiquitination, in line with known SMA phenotypes. These alterations in the SMA proteome increase further towards later stages of MN differentiation. In addition, we find differences in altered protein expression between SMA patients, which however, have similar biological functions. Finally, we highlight several known SMN-binding partners as well as proteins associated with ubiquitin-mediated proteolysis and evaluate their expression changes during MN differentiation. Altogether, our work provides a rich resource of molecular events during early stages of MN differentiation, containing potentially therapeutically interesting protein expression profiles for SMA.

2022-02-15 | PXD015115 | Pride

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data