Dysregulated synaptic gene expression and axonal neuropathology in a human iPSC-based model of familial Parkinson's disease
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE84684 | GEO | 2017/04/23
SECONDARY ACCESSION(S): PRJNA330836
REPOSITORIES: GEO
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Project description:α-Synuclein (αSyn) is the major gene linked to sporadic Parkinson's disease (PD), whereas the G209A (p.A53T) αSyn mutation causes a familial form of PD characterized by early onset and a generally severe phenotype, including nonmotor manifestations. Here we generated de novo induced pluripotent stem cells (iPSCs) from patients harboring the p.A53T mutation and developed a robust model that captures PD pathogenic processes under basal conditions. iPSC-derived mutant neurons displayed novel disease-relevant phenotypes, including protein aggregation, compromised neuritic outgrowth, and contorted or fragmented axons with swollen varicosities containing αSyn and Tau. The identified neuropathological features closely resembled those in brains of p.A53T patients. Small molecules targeting αSyn reverted the degenerative phenotype under both basal and induced stress conditions, indicating a treatment strategy for PD and other synucleinopathies. Furthermore, mutant neurons showed disrupted synaptic connectivity and widespread transcriptional alterations in genes involved in synaptic signaling, a number of which have been previously linked to mental disorders, raising intriguing implications for potentially converging disease mechanisms.
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Project description:Disease-modifying therapies remain an important unmet need for neurodegenerative diseases, including Parkinson’s disease (PD). The aim of this study was to investigate the molecular pathways affected by the multi-kinase inhibitor BX795, which is neuroprotective in an induced pluripotent stem cell (iPSC)-based model of familial PD. To this end, we performed proteomics analysis in iPSC-derived neurons from patients bearing the G209A (p.A53T) α-synuclein (αSyn) mutation vis-à-vis control neurons, in the absence or presence of BX795. Comparison between p.A53T versus control neurons in the absence of BX795, revealed differential expression of 640 proteins from which only 67 were down-regulated whilst the rest 573 were up-regulated. This large increase in protein expression was linked by GO enrichment analysis mainly to the biological processes of transcription, translation, protein synthesis and modification. Upon treatment with BX795, the levels of a cohort of 118 proteins, lying mostly within these biological processes and representing approximately 20% of the total dysregulated proteins in p.A53T neurons, were restored. Enrichment analysis using the DAVID and Reactome softwares showed that these proteins are predominantly associated with mRNA metabolism, mRNA transport and translation, protein metabolism and degradation processes. This outcome was specific to p.A53T-neurons as BX795 had no significant effect on the proteome of control neurons.
2023-03-10 | PXD019574 | Pride
Project description:The fact that Parkinsons disease (PD) can arise from numerous genetic mutations suggests a unifying molecular pathology underlying the various genetic backgrounds. In order to address this hypothesis, an integrated approach utilizing in vitro disease modeling and comprehensive transcriptome profiling was taken to advance our understanding of PD progression and the concordant downstream signaling pathways across divergent genetic predispositions. To model PD in vitro, neurons harboring disease-causing mutations were generated from patient-specific, induced pluripotent stem cells (iPSCs) and found to recapitulate several disease-related phenotypes. Signs of degeneration in PD midbrain dopaminergic (mDA) neurons were observed, reflecting the cardinal feature of PD. In addition, novel gene expression signatures were revealed for PD mDA neurons, providing molecular insights to disease phenotype observed in vitro, including oxidative stress vulnerability and altered neuronal activity. Notably, detailed transcriptome profiling of PD neurons showed that elevated RBFOX1, a gene previously linked to neurodevelopmental diseases, is responsible for a pattern of alternative RNA processing associated with PD-specific phenotypes in vitro.
2016-06-07 | E-MTAB-4586 | biostudies-arrayexpress
Project description:Parkinson's disease (PD) is a progressive neurodegenerative disorder, which is characterised by degeneration of distinct neuronal populations, including dopaminergic neurons of the substantia nigra. Here, we use a metabolomics profiling approach to identify changes to lipids in PD observed in sebum, a non-invasively available biofluid. We used liquid chromatography-mass spectrometry (LC-MS) to analyse 274 samples from participants (80 drug naïve PD, 138 medicated PD and 56 well matched control subjects) and detected metabolites that could predict PD phenotype. Pathway enrichment analysis shows alterations in lipid metabolism related to the carnitine shuttle, sphingolipid metabolism, arachidonic acid metabolism and fatty acid biosynthesis. This study shows sebum can be used to identify potential biomarkers for PD.
2020-12-21 | MTBLS2266 | MetaboLights
Project description:Parkinson’s disease (PD) is a prevalent neurodegenerative disorder that is characterized by the selective loss of midbrain dopamine (DA)-producing neurons and the formation of α-synuclein (α-syn)-containing inclusions named Lewy bodies (LBs). Here, we report that the loss of glucocerebrosidase (GCase), coupled with α-syn overexpression, result in substantial accumulation of detergent-resistant α-syn aggregates and Lewy body-like inclusions (LBLIs) in human midbrain-like organoids (hMLOs). These LBLIs exhibit a highly similar structure to PD-associated LBs, by displaying a spherically symmetric morphology with an eosinophilic core, and containing α-syn and ubiquitin. Importantly, hMLOs generated from PD patient-derived inducible pluripotent stem cells (iPSCs) harboring SNCA triplication also exhibit subsequent degeneration of DA neurons and LBLI formation upon chronic GCase inhibitor treatment. Taken together, our hMLOs harbouring two major PD risk factors (GCase deficiency and overproduced α-syn) successfully recapitulate major pathophysiological signatures of the disease, and highlight the broad utility of brain organoid technology in modeling human neurodegenerative diseases.
2021-08-13 | E-MTAB-7302 | biostudies-arrayexpress
Project description:Parkinson’s disease is characterised by progressive loss of dopaminergic (DA) neurons from the substantia nigra (SN) and intraneuronal accumulation of α-synuclein (αSyn) protein. Age is the biggest risk factor for Parkinson’s and has been suggested to create a vulnerable pre-parkinsonian state, but the drivers of this association are unclear. It is known that aging leads to increased αSyn expression in DA neurons and it is possible that this may alter molecular processes that are central to maintaining nigrostriatal integrity. To investigate this, adult female Sprague-Dawley rats received unilateral intranigral injection of adeno-associated viral (AAV) vector carrying wild-type human αSyn (AAV-αSyn) or control vector (AAV-Null). AAV-αSyn induced no detrimental effects on motor behaviour, but there was expression of human wild-type αSyn throughout the midbrain and ipsilateral striatum at 20 weeks post-surgery. Microarray analysis revealed that the gene most-upregulated in the ipsilateral SN of the AAV-αSyn group was the SKI Family Transcriptional Corepressor 1 (SKOR1). Bioenergetic state analysis of mitochondrial function found that SKOR1 overexpression reduced the maximum rate of cellular respiration. Furthermore, SKOR1 impaired neurite growth to the same extent as α-synuclein, and inhibited BMP-SMAD-dependent transcription, a pathway that promotes DA neuron survival and growth. Given the normal influence of ageing on DA neuron loss in human SN, the extent to which αSyn upregulates SKOR1 may influence whether an individual undergoes normal nigrostriatal ageing or reaches a threshold for prodromal PD. This provides new insight into mechanisms through which age-related changes may influence molecular mechanisms controlling neuronal integrity across the lifespan.
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Project description:The overall goal was to identify changes in gene expression following treatment with aSYN F110 compared to control (untreated). Alpha-synuclein (αSYN) protein has been observed in reactive astrocytes in PD patients’ brains, raising the question of how αSYN, neuroinflammation, and astrocytes interact in PD pathogenesis. Here, we examined the cellular changes triggered by tumor necrosis factor alpha (TNFα) and different αSYN species in astrocytes derived from induced pluripotent stem cells. Human astrocytes treated with TNFα displayed a strong reactive pro-inflammatory phenotype with upregulation of pro-inflammatory gene networks, activation of the NF-kB pathway, and release of pro-inflammatory cytokines, whereas those treated with high molecular weight αSYN fibrils acquired a reactive antigen (cross-)presenting phenotype with upregulation of MHC genes and increased HLA-DR/DQ/DP and HLA-F molecules at the cell surface. Surprisingly, cell surface location of MHC proteins was abrogated by larger F110 fibrils polymorph, despite the upregulation of MHC genes. A proteomics investigation further confirmed a direct interaction between astrocytic MHC proteins and αSYN fibril peptides. Interestingly, TNFα and αSYN fibrils competed to drive the astrocyte immune reactive response. The astrocyte immune responses were accompanied by an impaired ATP-generating mitochondrial respiration, which was exacerbated in PD astrocytes containing a PARK2-variant. Our data provide evidence for astrocytic involvement in PD pathogenesis and reveal their complex immune reactive responses to exogenous stressors.
2021-02-16 | GSE166769 | GEO
Project description:Parkinson's disease (PD) is defined by the degeneration of nigral dopaminergic (DA) neurons and can be caused by monogenic mutations of genes such as parkin. The lack of phenotype in parkin knockout mice suggests that human nigral DA neurons have unique vulnerabilities. Here we generate induced pluripotent stem cells from normal subjects and PD patients with parkin mutations. We demonstrate that loss of parkin in human midbrain DA neurons greatly increases the transcription of monoamine oxidases and oxidative stress, significantly reduces DA uptake and increases spontaneous DA release. Lentiviral expression of parkin, but not its PD-linked mutant, rescues these phenotypes. The results suggest that parkin controls dopamine utilization in human midbrain DA neurons by enhancing the precision of DA neurotransmission and suppressing dopamine oxidation. Thus, the study provides novel targets and a physiologically relevant screening platform for disease-modifying therapies of PD. Genomic DNA was isolated from each of the four lines of iPSCs and labeled with Cy5. Pooled sex mismatched normal human genomic DNA was labeled with Cy3. Both samples are hybridized together on RPCI 21K BAC aCGH array.
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Project description:The overall goal was to identify changes in gene expression following treatment with TNFa, monomeric, or fibril aSYN compared to control (untreated). Alpha-synuclein (αSYN) protein has been observed in reactive astrocytes in PD patients’ brains, raising the question of how αSYN, neuroinflammation, and astrocytes interact in PD pathogenesis. Here, we examined the cellular changes triggered by tumor necrosis factor alpha (TNFα) and different αSYN species in astrocytes derived from induced pluripotent stem cells. Human astrocytes treated with TNFα displayed a strong reactive pro-inflammatory phenotype with upregulation of pro-inflammatory gene networks, activation of the NF-kB pathway, and release of pro-inflammatory cytokines, whereas those treated with high molecular weight αSYN fibrils acquired a reactive antigen (cross-)presenting phenotype with upregulation of MHC genes and increased HLA-DR/DQ/DP and HLA-F molecules at the cell surface. Surprisingly, cell surface location of MHC proteins was abrogated by larger F110 fibrils polymorph, despite the upregulation of MHC genes. A proteomics investigation further confirmed a direct interaction between astrocytic MHC proteins and αSYN fibril peptides. Interestingly, TNFα and αSYN fibrils competed to drive the astrocyte immune reactive response. The astrocyte immune responses were accompanied by an impaired ATP-generating mitochondrial respiration, which was exacerbated in PD astrocytes containing a PARK2-variant. Our data provide evidence for astrocytic involvement in PD pathogenesis and reveal their complex immune reactive responses to exogenous stressors.
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