ASyn polyA-RNAseq in PD and unaffected cortical brain samples
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE40710 | GEO | 2012/10/04
SECONDARY ACCESSION(S): PRJNA174763
REPOSITORIES: GEO
Similar Datasets
Project description:We sought to more precisely characterize the different alpha-synuclein (aSyn) 3M-bM-^@M-^YUTR mRNA species in normal and PD human brain. High-throughput, whole-transcriptome sequencing of the 3M-bM-^@M-^YUTR ends of polyadenylated mRNA transcripts (termed pA-RNAseq; see Methods) was performed on a cohort of 17 unaffected and 17 PD cerebral cortical tissue samples. This revealed 5 aSyn 3M-bM-^@M-^YUTR isoforms, with lengths of 290, 480, 560, 1070 and 2520 nt. Of these, the 560 nt and 2520 nt forms were predominant. The existence and relative preponderance of these species was further confirmed by Northern Blot. We next hypothesized, that aSyn 3M-bM-^@M-^YUTR selection might be altered in PD. Comparison of pA-RNAseq profiles from PD and unaffected cerebral cortex samples revealed an increase in the preponderance of the long 3M-bM-^@M-^YUTR species (>560 nt) relative to shorter species (<560 nt). Such a relative increase in aSynL was confirmed by Quantitative real-time RT-PCR (rt-qPCR) and appeared specific for PD, as the increase was also observed by comparison to RNA from amyotrophic lateral sclerosis patient samples. We note that the modified aSyn 3M-bM-^@M-^YUTR selection associated with PD patient tissue was detected in cerebral cortex tissue, which typically harbors pathological evidence of the disease process without frank cell loss; thus, this phenotype is unlikely to be a secondary consequence of neurodegeneration. Comparison of 3'UTR ends of alpha-synuclein in PD and unaffected brain cortex
2012-10-04 | E-GEOD-40710 | biostudies-arrayexpress
Project description:Parkinsonâs disease (PD) and Dementia with Lewy bodies (DLB) are the two most common examples of synucleinopathies, i.e. human disorders that display intracellular deposition of the Alpha-synuclein (aSYN) protein. The two forms of aSYN deposits, intracellular Lewy bodies and Lewy neurites, are in the PD brain primarily found in the substantia nigra whereas in DLB brains they are diffusely spread in cortical and limbic areas. We are currently analyzing the protective effects on aSYN pathology by the molecular chaperone hsp70 in mice overexpressing wildtype human aSYN. Moreover, transgenic mice overexpressing hsp70 have been cross-bred with the aSYN mouse line. Intriguingly, the aSYN / hsp70 double transgenics display a pronounced reduction in biochemically assessed aSYN aggregation. Gene expression of these mice will not only provide insight into the disease mechanisms of aSYN pathology but its prevention by the overexpression of hsp70, leading to new potential avenues of treatment. Project 1: To investigate and compare alterations in gene expression profiles of brains from wild-type mice and mice overexpressing wildtype human aSYN, human hsp70 and aSYN / hsp70, respectively. The comparison of the expression profiles of the groups of mice: aSYN, Hsp70, aSYN/ Hsp70 and non-transgenic littermates will help to identify the genes that are involved in the mediation of aggregation toxicity of aSYN expression as well as the genes that may mediate an attenuation of aSYN pathology in hsp70-coexpressors. Project 1: Selection of animals Mice of 4 month old (n=6) of age of each background (aSYN, Hsp70, aSYN/ Hsp70 and non-transgenic littermates) will be used for RNA-extraction for a total of 24 mice. Preparation of samples For the proposed experiments, we will use the recommended procedures, as outlined by the consortium, for extracting and purifying RNA from whole brain homogenate. Briefly, RNA will be extracted by the trizol method and purified by using the RNeasy MinElute Cleanup (QIAGEN Inc., USA). RNA labeling and hybridization procedures will be carried out by the microarray consortium. SPECIAL NOTE: The samples will be sent upon availability. Gene Expression Microarray Analysis Six mice will be included in each group per timepoint to generate statistically testable data and limit the possible confound of individual mouse gene expression variations. The genome expression will be evaluated through the use of the GeneChip® Mouse Genome 430 2.0 Array (Affymetrix) for each individual mouse constituting a total of 24 arrays for the proposed study. Gene expression data interpretation will be assisted by the Microarray Consortium Center bioinformatics core.
2008-06-13 | E-GEOD-4758 | biostudies-arrayexpress
Project description:A growing body of evidence suggests that nuclear alpha-synuclein (aSyn) plays a role in the pathogenesis of Parkinson’s disease (PD). However, this question has been difficult to address as controlling the localization of aSyn in experimental systems often requires protein overexpression, which affects its aggregation propensity. To overcome this, we engineered Snca-NLS mice which localize endogenous aSyn to the nucleus. We characterized these mice on a behavioral, histological, and biochemical level to determine whether the increase of nuclear aSyn is sufficient to elicit PD-like phenotypes. SncaNLS mice exhibit age-dependent motor deficits and altered gastrointestinal function. We found that these phenotypes were not linked to aSyn aggregation or phosphorylation. Through histological analyses, we observed motor cortex atrophy in the absence of midbrain dopaminergic neurodegeneration. We sampled cortical proteomes of Snca-NLS mice and controls to determine the molecular underpinnings of these pathologies. Interestingly, we found several dysregulated proteins involved in dopaminergic signalling, including Darpp32, Pde10a, and Gng7, which we further confirmed was decreased in cortical samples of the Snca-NLS mice compared to controls. These results suggest that chronic endogenous nuclear aSyn can elicit toxic phenotypes in mice, independent of its aggregation. This model raises key questions related to the mechanism of aSyn toxicity in PD and provides a new model to study an underappreciated aspect of PD pathogenesis.
2022-04-06 | PXD032065 | Pride
Project description:The accumulation of α-synuclein (ASyn) has been observed in several lysosomal storage diseases (LSD), but it remains unclear if the accumulation of ASyn contributes to the pathology. The mitochondria degeneration, reduced expression of manganese superoxide dismutase 2, and reactive oxygen species-mediated oxidative damage were observed in the neurons of Hexb-/- mice. Gene expression in the brain of 14-week-old Hexb-/- ASyn+/+, Hexb-/- Asyn-Tg, and Hexb-/- ASyn-/- mice were analyzed.
2015-05-12 | E-GEOD-68748 | biostudies-arrayexpress
Project description:Parkinson’s disease (PD) is a neurodegenerative disorder associated with the accumulation of intraneuronal protein aggregates called Lewy bodies. These inclusions contain aberrantly folded and aggregated alpha-synuclein (aSyn), a key protein involved in the pathology of PD, for which the mechanisms of toxicity are still largely unknown. Recent studies suggest that the conformational changes occurring during aSyn aggregation process can be expected to lead to alterations in the interactome of aSyn. Therefore, identifying changes in the interactome of monomeric and aggregated states of aSyn could help to understand the underlying molecular mechanisms of PD. Despite substantial efforts, current interactomics approaches do not enable determining structure-specific PPIs and their interaction interfaces on a proteome-wide scale. To address this limitation, we here applied the structural proteomics method limited proteolysis–mass spectrometry to systematically identify structure-specific PPIs of aSyn by probing protein structural alterations within cellular extracts upon treatment with monomeric and aggregated, fibrillar states of aSyn. Overall, we identified several previously known interactors of both monomeric and aggregated aSyn as well as novel putative structure-specific interactors including their interaction interfaces and protein binding parameters in situ. These results may constitute an important step in the understanding of how distinct structural states of disease-associated proteins are involved in disease mechanisms.
2024-02-10 | PXD039784 | Pride
Project description:Many risk loci for Parkinson’s disease (PD) have been identified by genome-wide association studies (GWAS), but target genes and mechanisms remain largely unknown. We linked the GWAS-derived chromosome 7 locus (sentinel SNP rs199347) to GPNMB, through colocalization analyses of expression quantitative trait locus (eQTL) and PD risk signals, confirmed by allele-specific expression studies in human brain. In cells, Glycoprotein Nonmetastatic Melanoma Protein B protein (GPNMB) co-immunoprecipitated and co-localized with alpha-synuclein (aSyn). In induced pluripotent stem cell-derived neurons, loss of GPNMB resulted in loss of ability to internalize aSyn fibrils and develop aSyn pathology. In 781 PD and 59 control biosamples, GPNMB was elevated in PD plasma, associating with disease severity. Thus, GPNMB represents a PD risk gene, with potential for biomarker development and therapeutic targeting.
2022-06-17 | GSE206327 | GEO
Project description:Alpha-synuclein (aSyn) is widely portrayed as the main culprit on Parkinson’s Disease (PD) pathophysiology. However, the precise molecular function of the protein remains elusive. Recent evidence suggests that aSyn may play a role on transcription regulation, possibly by modulating the acetylation status of histones. Our study aimed to evaluate the impact of wild-type (WT) and mutant A30P aSyn on gene expression, in a dopaminergic neuronal cell model, and decipher potential mechanisms behind aSyn-induced transcriptional deregulation. We performed RNA-sequencing in Lund Human Mesencephalic (LUHMES) cells expressing endogenous (control) or increased WT or A30P aSyn levels. Compared to control, LUHMES cells expressing aSyn exhibited robust changes in the expression of several genes, including downregulation of major genes involved in DNA repair. Expressing WT aSyn, unlike A30P aSyn, led to increased DNA damage and phosphorylated p53 levels. In our dopaminergic neuronal cell model, aSyn expression promoted lower histone 3 acetylation levels. Excitingly, treatment with sodium butyrate, a histone deacetylase inhibitor (HDACi), was able to rescue WT aSyn-induced DNA damage, possibly via upregulation of genes involved in DNA repair. Overall, our findings provide compelling, pioneer evidence for a novel mechanism associated with aSyn neurotoxicity in dopaminergic cells, which could be ameliorated with a HDACi. Prospective studies will be crucial to further validate these findings and its relevance to our knowledge of PD.
2017-03-31 | GSE89115 | GEO
Project description:Alpha-synuclein (aSyn) is a central player in the pathogenesis of synucleinopathies due to its accumulation in typical protein aggregates in the brain. However, it is still unclear how it contributes to neurodegeneration. Type-2 diabetes mellitus is a risk factor for Parkinson’s disease (PD) and, interestingly, a common molecular alteration among these disorders is the age-associated increase in protein glycation. We hypothesized that glycation-induced neuronal dysfunction might be a contributing factor in synucleinopathies. Here, we dissected the specific impact of methylglyoxal (MGO, a glycating agent) in mice overexpressing aSyn in the brain. We found that MGO-glycation potentiates motor, cognitive, olfactory, and colonic dysfunction in aSyn transgenic (Thy1-aSyn) mice that received a single dose of MGO via intracerebroventricular (ICV) injection. aSyn accumulates in the midbrain, striatum, and prefrontal cortex, and protein glycation is increased in the cerebellum and midbrain. SWATH mass spectrometry analysis, used to quantify changes in the brain proteome, revealed that MGO mainly increase glutamatergic-associated proteins in the midbrain (NMDA, AMPA, glutaminase, VGLUT and EAAT1), but not in the prefrontal cortex, where it mainly affects the electron transport chain. Notably, the glycated proteins in the midbrain of Thy1-aSyn mice that received MGO strongly correlate with PD and dopaminergic pathways. Overall, we demonstrated that MGO-induced glycation accelerates PD-like sensorimotor and cognitive alterations and suggest that the increase of glutamatergic signaling may underly these events. Our study sheds new light into the enhanced vulnerability of the midbrain in PD-related synaptic dysfunction and suggests that glycation suppressors and anti-glutamatergic drugs may hold promise as disease-modifying therapies for synucleinopathies.
2022-05-20 | PXD032832 | Pride
Project description:Parkinson’s disease (PD) is caused by loss of dopaminergic (DA) neurons in the substantia nigra (SN). Although PD pathogenesis is not fully understood, studies implicate perturbations in gene regulation, mitochondrial function, and neuronal activity. MicroRNAs (miRs) are small gene regulatory RNAs that inhibit diverse subsets of target mRNAs, and several studies have noted miR expression alterations in PD brains. For example, miR-181a is abundant in brain and is increased in PD patient brain samples; however, the disease relevance of this remains unclear. Herein, we show that miR-181 target mRNAs are broadly down-regulated in aging and PD brains. To address if the miR‑181 family plays a role in PD pathogenesis, we generated adeno-associated viruses (AAV) to overexpress and inhibit miR-181 isoforms. After co-injection with AAV overexpressing alpha-synuclein (aSyn) into mouse SN (PD model), we found that moderate miR-181a/b overexpression exacerbated aSyn-induced DA neuronal loss, whereas miR‑181 inhibition was neuroprotective, relative to controls (GFP-alone and/or scrambled RNA). Also, prolonged miR-181 overexpression in SN alone elicited measurable neurotoxicity coincident with an increased immune response. RNA-seq analyses revealed that miR-181a/b inhibits genes involved in synaptic transmission, neurite outgrowth, and mitochondrial respiration, along with several genes having known protective roles and genetic links in PD.
2022-03-23 | GSE196441 | GEO
Project description:Alpha synuclein (SNCA) has been linked to neurodegenerative diseases (synucleinopathies) that include Parkinson’s disease (PD). Although the primary neurodegeneration in PD involves nigrostriatal dopaminergic neurons, more extensive yet regionally selective neurodegeneration is observed in other synucleinopathies. Furthermore, SNCA is ubiquitously expressed in neurons and numerous neuronal systems are dysfunctional in PD. Therefore it is of interest to understand how overexpression of SNCA affects neuronal function in regions not directly targeted for neurodegeneration in PD. To gain a better understanding of the consequences of excessive SNCA expression on basal ganglia function, we performed transcriptome analysis of striatal tissue from male Thy1-aSyn-mice and wt littermates. The present study investigated the consequences of SNCA overexpression on cellular processes and functions in the striatum of mice overexpressing wild-type, human SNCA under the Thy1 promoter (Thy1-aSyn mice) by transcriptome analysis. The analysis revealed alterations in multiple biological processes in the striatum of Thy1-aSyn mice, including synaptic plasticity, signaling, transcription, apoptosis, and neurogenesis. The present study investigated the consequences of SNCA overexpression on cellular processes and functions in the striatum of mice overexpressing wild-type, human SNCA under the Thy1 promoter (Thy1-aSyn mice) by transcriptome analysis. The analysis revealed alterations in multiple biological processes in the striatum of Thy1-aSyn mice, including synaptic plasticity, signaling, transcription, apoptosis, and neurogenesis.
2012-02-11 | GSE35723 | GEO