SMN deficiency in spinal muscular atrophy causes widespread intron retention and DNA damage
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus Homo sapiens
PROVIDER: GSE87281 | GEO | 2017/03/21
SECONDARY ACCESSION(S): PRJNA343962
REPOSITORIES: GEO
Similar Datasets
Project description:Although recent advances in gene therapy provide hope for spinal muscular atrophy (SMA) patients, the pathology remains the leading genetic cause of infant mortality. SMA is a monogenic pathology that originates from the loss of the SMN1 gene in most cases or mutations in rare cases. Interestingly, SMN1 mutations occur broadly either within the TUDOR methyl-arginine (Rme) reader domain of SMN or its carboxy terminal oligomerization domain. We hypothesized that in SMN1 mutant cases, SMA may emerge from aberrant protein-protein interactions between SMN and key neuronal factors. Using a proximity-dependent biotinylation proteomic (BioID) approach, we have identified and validated a number of SMN-interacting proteins, including Fragile X mental retardation family members (FMRFM), such as FMRP itself as well as FXR1 and FXR2, some depending on a wild-type version of the TUDOR domain.
2022-10-19 | PXD030970 | Pride
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). 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
2020-08-11 | GSE154106 | GEO
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
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
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
Project description:Spinal Muscular Atrophy (SMA) is well-known to be caused by mutations in the gene Survival of Motor Neuron 1 (SMN1). Because this gene is ubiquitously expressed, it remains poorly understood why motor neurons (MNs) are one of the most affected cell types. To begin to address this question, we carried out RNA-sequencing studies using fixed, antibody-labeled and purified MNs produced from control and SMA patient-derived induced pluripotent stem cells (iPSCs). We found SMA-specific changes in MNs, including hyper-activation of the endoplasmic reticulum (ER) stress pathway and enhanced apoptosis. Functional studies demonstrated that inhibition of ER stress improves overall MN health and survival in vitro even in MNs with low SMN levels. In SMA mice, we show that systemic delivery of an ER stress inhibitor that crosses the blood-brain-barrier led to preservation of MNs in the spinal cord and prolonged survival of these mice. Therefore, our study implies that selective activation of ER stress underlies MN death in SMA. Moreover, the approach we have taken would be broadly applicable to studying disease-prone human cells in heterogeneous cultures. total RNA collected from ES cell and patient ES cell derived spinal motor neurons
2015-09-01 | E-GEOD-69175 | biostudies-arrayexpress
Project description:Spinal muscular atrophy (SMA) due to loss-of-function of SMN protein is associated with severe loss of voluntary muscle control and is a leading inherited cause of infant mortality. SMA treatments will benefit from in-depth knowledge of functional pathways disrupted in disease and identification of SMN modulators. Here, we present a comprehensive temporal profile of proteogenomic expression patterns in developing mouse spinal cords (Δ7 model), alongside endpoint analyses of human spinal and ventral root tissues in SMA disease, identifying targets for assessing disease progression and treatment response. SMA disease results in development-associated deficiencies in transcription, translation initiation, intracellular transport, and protein folding, and diminished RNA translation efficiency for proteins important in axon development/myelination. The broad impact of SMN deficiency prompted the search for co-regulated proteins that modulate SMN protein levels, resulting in identification of the anaphase promoting complex/cyclosome (APC/C) E3 ubiquitin ligase as a potential modulator of SMN protein stability. Functional studies of APC/C showed that both SMN and HuD are specific interactors of the APC/C in neurons and that selective APC/C inhibition significantly limited SMN and HuD degradation. Finally, we demonstrate that APC/C inhibition rescues motor axon defects characteristic of SMA in a zebrafish model of SMA disease.
2022-01-18 | GSE128129 | GEO
Project description:Spinal muscular atrophy (SMA) is a neuromuscular disorder caused by loss of survival motor neuron (SMN) protein. While SMN restoration therapies are beneficial, they are not a cure. We aimed to identify novel treatments to alleviate muscle pathology combining transcriptomics, proteomics and perturbational datasets. This revealed potential drug candidates for repurposing in SMA. One of the candidates, harmine, was further investigated in cell and animal models, improving multiple disease phenotypes, including SMN expression and lifespan. Our work highlights the potential of multiple and parallel data driven approaches for the development of novel treatments for use in combination with SMN restoration therapies.
2020-05-14 | GSE150517 | GEO
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
Project description:Spinal Muscular Atrophy (SMA) is a devastating neuromuscular disease caused by hypomorphic loss of function in the Survival Motor Neuron (SMN) protein. SMA presents across broad spectrum of disease severity. Unfortunately, vertebrate models of intermediate SMA have been difficult to generate and are thus unable to address key aspects of disease etiology. To address these issues, we developed a Drosophila model system that recapitulates the full range of SMA severity, allowing studies of pre-onset biology as well as late-stage disease processes. In this study, TMT-based quantitative proteomic profiling was performed on mild and intermediate Drosophila models of SMA to elucidate proteins and pathways that contribute to the disease. Using this approach, we elaborated a role for the SMN complex in the regulation of innate immune signaling.
2024-04-11 | PXD046801 | Pride