A-synuclein accumulation in an iPSC derived model of early onset sporadic Parkinson’s Disease reveals novel drug targets
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA494382 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR7949560.fastq.gz | Fastqsanger.gz | |||
| SRR7949570.fastq.gz | Fastqsanger.gz | |||
| SRR7949561.fastq.gz | Fastqsanger.gz | |||
| SRR7949571.fastq.gz | Fastqsanger.gz | |||
| SRR7949562.fastq.gz | Fastqsanger.gz |
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Project description:Early onset Parkinson’s Disease (onset <50 years) accounts for between 10-20 percent of all patients. While some of these cases are associated with specific mutations, the majority are sporadic where the cause is unknown. We generated induced pluripotent stem cells from sporadic early onset patients and differentiated them to dopamine neurons. At early stages in culture (30 days) we found significant elevations in soluble α-synuclein protein levels when compared to controls. This was associated with reductions in lysosomal membrane proteins such as LAMP1 and an increase in phosphorylated protein kinase C-α (p-PKCα). Testing activators of lysosomal function showed that specific phorbal esters reduced both α-synuclein and p-PKCα levels and increased LAMP1 expression. Interestingly, very low doses of the drug PEP005 were able to reduce α-synuclein levels without affecting p-PKCα. Similar effects of PEP005 on α-synuclein expression were seen following infusion into the mouse brain. Our data show that early onset sporadic Parkinson’s Disease can be accurately predicted using a ratio of α-synuclein and p-PKCα in dopamine neural cultures derived from patient iPSC’s and that specific phorbal esters can alter both biomarkers making these drugs promising candidates to treat Parkinson’s Disease.
2019-12-06 | PXD011326 | Pride
Project description:The primary mechanism and subcellular localisation of α-synuclein toxicity in Parkinson’s disease pathogenesis remain unknown. We spatially and temporally resolved proteomic and transcriptomic changes in human iPSC-derived dopaminergic neurons with increasing burden of pathological α-synuclein. We found that misfolded α-synuclein proteoforms, signified by the formation of nanoscale intraneuronal puncta, are associated with impaired translocon function at the endoplasmic reticulum (ER). We show that α-synuclein interacts with Sec61A in iPSC-derived dopaminergic neurons and in post-mortem brain tissue from patients with Parkinson’s disease. This interaction interferes with the co-translational translocation of ER-processed proteins including the vacuolar-type ATPase V0a1 subunit, glucocerebrosidase, and Cathepsin B, causing defective organelle function such as reduced lysosomal acidification, leading to increased extracellular vesicle release of α-synuclein. Defective ER-translocation was associated with increased ribosomal UFMylation and proteasomal recruitment but not activation of the unfolded protein response. Reduction of pathological α-synuclein by either CRISPRi to decrease α-synuclein expression or pharmacological activation of proteasomal degradation with repurposed drugs mitigates the ER defect. Our study offers a unifying mechanistic link between α-synuclein pathology and dysregulation of diverse organelle-associated proteins that are both Sec61A translocon substrates and genetic modifiers of Parkinson’s disease risk. Our data also provide a therapeutic rationale for proteasomal activation in early Parkinson’s disease.
2026-07-06 | GSE276559 | GEO
Project description:The primary mechanism and subcellular localisation of α-synuclein toxicity in Parkinson’s disease pathogenesis remain unknown. We spatially and temporally resolved proteomic and transcriptomic changes in human iPSC-derived dopaminergic neurons with increasing burden of pathological α-synuclein. We found that misfolded α-synuclein proteoforms, signified by the formation of nanoscale intraneuronal puncta, are associated with impaired translocon function at the endoplasmic reticulum (ER). We show that α-synuclein interacts with Sec61A in iPSC-derived dopaminergic neurons and in post-mortem brain tissue from patients with Parkinson’s disease. This interaction interferes with the co-translational translocation of ER-processed proteins including the vacuolar-type ATPase V0a1 subunit, glucocerebrosidase, and Cathepsin B, causing defective organelle function such as reduced lysosomal acidification, leading to increased extracellular vesicle release of α-synuclein. Defective ER-translocation was associated with increased ribosomal UFMylation and proteasomal recruitment but not activation of the unfolded protein response. Reduction of pathological α-synuclein by either CRISPRi to decrease α-synuclein expression or pharmacological activation of proteasomal degradation with repurposed drugs mitigates the ER defect. Our study offers a unifying mechanistic link between α-synuclein pathology and dysregulation of diverse organelle-associated proteins that are both Sec61A translocon substrates and genetic modifiers of Parkinson’s disease risk. Our data also provide a therapeutic rationale for proteasomal activation in early Parkinson’s disease.
2026-07-06 | GSE276377 | GEO
Project description:Although α-synucleinis implicated in the pathogenesis of Parkinson’s disease and related disorders, it remains unclear whether specific conformations or levels of α-synuclein assemblies are toxic and how they cause progressive loss of human dopaminergic neurons. To address this issue, we used iPSC-derived dopaminergic neurons with a-synuclein triplication or controls where endogenous α-synuclein was imprinted into synthetic or disease-relevant conformations. We used α-synuclein fibrils generated de novo or amplified from homogenates of brains affected with Parkinson’s disease (n=3) .We found that a 2.5-fold increase in α-synuclein levels in α-synuclein gene triplication neurons promoted seeded aggregation in a dose and time-dependent fashion, which was associated with a further increase in α-synuclein gene expression.Transcriptomic analysis and isogenic correction of α-synuclein triplication revealed that intraneuronal α-synuclein levels solely and sufficiently explained vulnerability to cell death.
2020-09-02 | GSE149632 | GEO
Project description:Althougha-synuclein is implicated in the pathogenesis of Parkinson’s disease and related disorders, it remains unclear whether specific conformations or levels ofa-synuclein assemblies are toxic and how they cause progressive loss of human dopaminergic neurons. To address this issue, we used iPSC-derived dopaminergic neurons with a-synuclein triplication or controls where endogenous a-synuclein was imprinted into synthetic or disease-relevant conformations. We used a-synuclein fibrils generated de novo or amplified from homogenates of brains affected with Parkinson’s disease (n=3) or multiple system atrophy (n=5). We found that a 2.5-fold increase in a-synuclein levels in a-synuclein gene triplication neurons promoted seeded aggregation in a dose and time-dependent fashion, which was associated with a further increase in a-synuclein gene expression. Progressive neuronal loss was observed only in a-synuclein triplication neurons seeded with brain-amplified fibrils. Transcriptomic analysis and isogenic correction of a-synuclein triplication revealed that intraneuronalalpha-synuclein levels solely and sufficiently explained vulnerability to neuronal death
2021-04-13 | GSE171999 | GEO
Project description:The accumulation of misfolded α-synuclein and the loss of dopaminergic neurons are hallmarks of Parkinson’s disease (PD), contributing to the development of synucleinopathies. Although considerable progress has been made in understanding α-synuclein's role in PD pathology, the precise mechanisms involved remain unclear. Human midbrain organoids (hMOs) have emerged as valuable models for studying PD, yet the lack of microglia limits the ability to investigate neuroimmune interactions. Recent studies show that integrating microglia into hMOs enhances neuronal maturation and functionality. Here, we generated a human midbrain assembloid model by incorporating iPSC-derived microglia into midbrain organoids from healthy control individuals and a PD patient carrying the SNCA triplication (3xSNCA) mutation. Our results show that 3xSNCA microglia alone are sufficient to induce early, endogenous formation of phosphorylated α-synuclein (pS129) pathology in the absence of exogenous fibril seeding. This PD-pathology emerged as early as day 50 of culture and was not observed in models lacking microglia. These findings highlight a critical role for patient-derived microglia in driving α-synuclein pathology and provide a physiologically relevant platform for studying early neuroimmune mechanisms in PD and testing potential therapeutic strategies.
2026-06-05 | GSE299260 | GEO
Project description:Parkinson’s disease (PD) is a movement disorder characterized by the accumulation of alpha-synuclein aggregates leading to dopaminergic neuron loss in the substantia nigra. While PD has been associated with environmental and microbiome changes, our ability to assess the mechanistic impact of these factors on synuclein aggregation in cells has remained limited. Here, we designed and optimized a high-throughput optical screening system to assess the effect of metabolites and small molecules on synuclein aggregation in cell lines expressing a synuclein-fluorescent protein fusion and treated with pre-formed fibrils (PFFs). Using this assay, we identified several compounds that modulate synuclein aggregate accumulation in cells, including harman, a β-carboline that led to reduced synuclein aggregation. We further investigated the transcriptional effect of harman and PFFs and identified changes in peroxiredoxins as a potential mechanism linking harman to aggregate accumulation. Altogether, this work establishes a pipeline to prioritize small molecules that can impact synuclein aggregate formation.
2026-06-30 | GSE328400 | GEO
Project description:Alpha-synuclein (αSyn) is an intrinsically disordered protein that accumulates in the brains of patients with Parkinson’s disease and forms inclusions in neurons called Lewy Bodies. While the mechanism underlying the dysregulation of αSyn in Parkinson’s disease is unclear, it is thought that prionoid cell-to-cell propagation of αSyn has an important role. Through a high throughput screen, we recently identified 38 genes whose knock down modulates αSyn propagation. Follow up experiments were undertaken for two of those genes, TAX1BP1 and ADAMTS19, to study the mechanism with which they regulate αSyn homeostasis. We used a recently developed M17D neuroblastoma cell line expressing triple mutant (E35K+E46K+E61K) “3k” αSyn under doxycycline induction. 3k αSyn spontaneously forms inclusions that show ultrastructural similarities to Lewy Bodies. Experiments using that cell line showed that TAX1BP1 and ADAMTS19 regulate how αSyn interacts with lipids and phase separates into inclusions, respectively, adding to the growing body of evidence implicating those processes in Parkinson’s disease. Through RNA sequencing, we identified several genes that are differentially expressed after knock-down of TAX1BP1 or ADAMTS19. Burden analysis revealed that those differentially expressed genes (DEGs) carry an increased frequency of rare risk variants in Parkinson’s disease patients versus healthy controls, an effect that was independently replicated across two separate cohorts (GP2 and AMP-PD). Weighted gene co-expression network analysis (WGCNA) showed that the DEGs cluster within modules in regions of the brain that develop high degrees of αSyn pathology (basal ganglia, cortex). We propose a novel model for the genetic architecture of sporadic Parkinson’s disease: increased burden of risk variants across genetic networks dysregulates pathways underlying αSyn homeostasis, thereby leading to pathology and neurodegeneration.
2025-02-17 | GSE276032 | GEO
Project description:Mutations in glucocerebrosidase (GBA) are the most prevalent genetic risk factor for Lewy body disorders (LBD) – collectively Parkinson’s disease, Parkinson’s disease dementia and dementia with Lewy bodies. Despite this genetic association, it remains unclear how GBA mutation contributes to the susceptibility of developing LBD. We investigated relationships between LBD-specific glucocerebrosidase deficits, GBA-related pathways, and α-synuclein levels in post-mortem brain tissue from LBD and controls with and without GBA mutations. Our study shows that LBD brains, regardless of GBA mutations, are characterised by altered sphingolipid metabolism, with prominent changes in ceramide species. Since extracellular vesicles (EV) could be involved in LBD pathogenesis by spreading disease linked lipids and proteins, we investigated EV derived from post-mortem cerebrospinal fluid (CSF) and brain tissue from GBA mutation carriers and non-carriers. EV purified from LBD post-mortem CSF and frontal cortex are heavily loaded with ceramides and neurodegeneration-linked proteins including alpha-synuclein and amyloid precursor protein. Our in vitro studies demonstrate that LBD EV constitute a “pathological package” capable of inducing aggregation of wild type alpha-synuclein, potentially through a combination of alpha-synuclein-ceramide interaction and the presence of pathological forms of alpha-synuclein. Together our findings indicate that abnormalities in ceramide metabolism are a feature of LBD, constituting a promising source of biomarkers. GBA mutation likely accelerates the pathological process occurring in sporadic LBD, probably through endolysosomal deficiency, but does not induce alpha-synucleinopathy since healthy normal GBA mutation carriers without alpha-synuclein pathology occur.
2021-11-02 | PXD026980 | Pride
Project description:Recent advances in generating 3 dimensional (3D) organoid systems from stem cells offer new possibilities for disease modeling. In this study, we generate isogenic 3D midbrain organoids with or without a Parkinson’s disease-associated LRRK2 G2019S mutation. LRRK2-G2019S midbrain organoids derived from LRRK2 targeted human iPSCs in vitro have LRRK2-associated sporadic Parkinson's disease phenotypes. Midbrain-like 3D organoids expressing LRRK2-G2019S showed dynamic changes in globle gene expression.
2019-02-02 | GSE125234 | GEO