Gene expression profiling of LMC and MMC motor neurons in SMA mice
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE81245 | GEO | 2017/12/12
SECONDARY ACCESSION(S): PRJNA321040
REPOSITORIES: GEO
Similar Datasets
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: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: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
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: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
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) 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: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
Project description:Spinal muscular atrophy (SMA) is a motor neuron (MN) disorder caused by mutations in SMN1. The reasons of MNs selective vulnerability linked to SMN reduction remain unclear. To address this question, we performed deep RNA sequencing on SMA human MNs to detect specific altered splicing/expressed genes and to identify the presence of a common sequence motif in these genes. Many deregulated genes, such as Neurexin and Synaptotagmin families, are implicated in critical MN-function like axonogenesis and synapses. Motif-enrichment analyses of differentially expressed/spliced genes, including Neurexin2 (NRXN2), revealed a common Motif, Motif-7, which is target of SYNCRIP protein. Interestingly, SYNCRIP interacts only with full-length SMN, binding and modulating several MN transcripts, including SMN itself. SYNCRIP overexpression rescued SMA-MNs, due to the consequent increase of SMN and their down-stream target NRXN2, through a positive loop mechanism. SMN/SYNCRIP complex through motif-7 might account for selective MN degeneration and represent a potential therapeutic target.
2018-10-12 | GSE108094 | GEO
Project description:Spinal Muscular Atrophy (SMA) is typically characterized as a motor neuron disease, but extra-neuronal phenotypes are present in almost every organ in severely affected patients and animal models. Extra-neuronal phenotypes were previously underappreciated as patients with severe SMA phenotypes usually died in infancy; however, with current treatments for motor neurons which increase patient lifespan, impaired function of peripheral organs may develop into significant future comorbidities and lead to new treatment-modified phenotypes. Fatty liver is seen in animal models of SMA, but generalizability to patients and whether this is due to hepatocyte-intrinsic Survival Motor Neuron (SMN) protein deficiency and/or subsequent to skeletal muscle denervation is unknown. If liver pathology in SMA is SMN-dependent and hepatocyte-intrinsic, this provides proof of concept that SMN repleting therapies must target extra-neuronal tissues as well as motor neurons for optimal patient outcome. Here we show that fatty liver is present in SMA and that SMA patient-specific iHeps are susceptible to steatosis. Using proteomics, functional studies and CRISPR/Cas9 gene editing, we confirm that fatty liver in SMA is a primary SMN-dependent hepatocyte-intrinsic liver defect associated with mitochondrial and other hepatic metabolism dysfunctions. These pathologies require monitoring and indicate the need for systematic clinical surveillance and additional and/or combinatorial therapies to ensure continued SMA patient health.
2024-05-09 | PXD045401 | JPOST Repository