Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA212736 | ENA |
REPOSITORIES: ENA
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Project description:Parkinson’s disease (PD) is characterized by degeneration of dopaminergic neurons in the substantia nigra pars compacta, but the molecular events preceding neuronal loss remain unclear. Here, we combine spatial transcriptomics, spatial proteomics, and α-synuclein (αSyn) seed amplification assays to profile post-mortem midbrain tissue from controls, incidental Lewy body disease (iLBD), PD, Alzheimer’s disease (AD), and AD with Lewy body pathology (AD+LBP). We find that αSyn seeding activity correlates with dopaminergic neuron loss in PD-spectrum cases but not in AD-associated LBP, indicating disease-context dependent relationships between αSyn pathology and neurodegeneration. In iLBD, before overt substantia nigra Lewy pathology or detectable αSyn aggregation, we detect increased expression of the complement component C1QC together with loss of inhibitory synaptic markers. These findings support early complement-associated remodeling of inhibitory synapses as a potential pathogenic event preceding overt αSyn aggregation and neuronal degeneration in PD.
2026-06-09 | PXD062998 | Pride
Project description:Subjects with incidental Lewy body disease (iLBD) may represent the premotor stage of Parkinson’s disease (PD). To identify molecular mechanisms underlying neuronal dysfunction and alpha--synuclein pathology in the premotor phase of PD, we investigated the transcriptome of post-mortem substantia nigra (SN) of iLBD, PD donors and age-matched controls with Braak alpha--synuclein stage ranging from 0-6. In Braak alpha--synuclein stages 1 and 2, we observed deregulation of pathways linked to axonal degeneration, unfolded protein response (UPR), immune response and endocytosis, including axonal guidance signaling, protein kinase A signaling, mTOR signaling, EIF2 signaling and clathrin-mediated endocytosis. In Braak stages 3 and 4, we observed a deregulation in pathways involved in protein translation and cell survival, including mTOR and EIF2 signaling. In Braak stages 5 and 6, we observed deregulation of pathways such as dopaminergic signaling, axonal guidance signaling and thrombin signaling. Throughout the progression of PD pathology, we observed a deregulation of mTOR, EIF2 and regulation of eIF4 and p70S6K signaling in the SN. This implicates that molecular mechanisms related to UPR, axonal dysfunction, endocytosis and immune response are an early event in PD pathology, and may hold the key to altering the disease progression in PD.
2015-05-12 | GSE49036 | GEO
Project description:Analysis of substantia nigra from postmortem brains of 4 patients with Parkinson’s disease (PD). Results provide insight into the molecular processes perturbed in the PD substantia nigra.
2011-01-20 | GSE20314 | GEO
Project description:Systematic meta-analysis and replication of genome-wide expression studies identifies molecular pathways of Parkinson’s disease. Snap-frozen human substantia nigras (SNs) of 16 individuals with a clinicopathological diagnosis of incidental Lewy body (ILB) disease with Lewy bodies detected in the brainstem nuclei of locus coeruleus and substantia nigra, but generally not in higher cortical regions consistent with Braak stage 3 criteria for Parkinson's disease (PD), and 17 age-, sex-, postmortem interval-, and RNA integrity number-matched controls, who were clinicopathologically within normal limits for age collected under the rapid-autopsy program of Sun Health Research Institute or by the Harvard Brain Tissue Resource Center at McLean Hospital, were used for gene expression analyses in stage 2. Protocols were approved by the Institutional Review Board of Brigham and Women’s Hospital.
2011-01-20 | GSE20159 | GEO
Project description:Pesticide exposure is increasingly recognised as a potential environmental factor contributing to the onset of idiopathic Parkinson’s disease, yet the molecular mechanisms underlying this connection remain unclear. This study aims to explore how pesticide exposure disrupts key brain regions involved in Parkinson’s disease pathology by reshaping gene expression and epigenetic landscapes. Using the well established rotenone rat model of the disease, we used H3K27ac ChIP-sequencing and RNA-sequencing to profile active regulatory elements and transcriptional activity in the substantia nigra and cortex. We identified widespread transcriptomic and epigenetic differences which are consistent across the assays. Our results indicate there is a strong immune response to rotenone localised to the substantia nigra and highlight an enrichment of immune-related motifs in this brain region, suggesting that the immune response is at least partially driven by gene regulatory mechanisms. We also noted an increase in C1q complement pathway activity in the substantia nigra. In contrast, we identified widespread dysregulation of synaptic function at the gene regulatory level in the cortex of these same rats. Our results highlight a role for gene regulatory mechanisms potentially mediating the effects of pesticide exposure, driving region-specific functional responses in the brain that may contribute to the pathology of Parkinson’s disease.
2025-06-18 | GSE280519 | GEO
Project description:Pesticide exposure is increasingly recognised as a potential environmental factor contributing to the onset of idiopathic Parkinson’s disease, yet the molecular mechanisms underlying this connection remain unclear. This study aims to explore how pesticide exposure disrupts key brain regions involved in Parkinson’s disease pathology by reshaping gene expression and epigenetic landscapes. Using the well established rotenone rat model of the disease, we used H3K27ac ChIP-sequencing and RNA-sequencing to profile active regulatory elements and transcriptional activity in the substantia nigra and cortex. We identified widespread transcriptomic and epigenetic differences which are consistent across the assays. Our results indicate there is a strong immune response to rotenone localised to the substantia nigra and highlight an enrichment of immune-related motifs in this brain region, suggesting that the immune response is at least partially driven by gene regulatory mechanisms. We also noted an increase in C1q complement pathway activity in the substantia nigra. In contrast, we identified widespread dysregulation of synaptic function at the gene regulatory level in the cortex of these same rats. Our results highlight a role for gene regulatory mechanisms potentially mediating the effects of pesticide exposure, driving region-specific functional responses in the brain that may contribute to the pathology of Parkinson’s disease.
2025-06-18 | GSE280520 | GEO
Project description:Parkinson’s disease (PD) is a neurodegenerative disease characterized by the death of dopaminergic neurons in the substantia nigra and the formation of Lewy bodies that are composed of aggregated α-synuclein (α-Syn). However, the factors that regulate α-Syn pathology and nigrostriatal dopaminergic degeneration remain poorly understood. Previous studies demonstrate cholesterol 24-hydroxylase (CYP46A1) increases the risk for PD. Moreover, 24-hydroxycholesterol (24-OHC), a brain-specific oxysterol that is catalyzed by CYP46A1, is elevated in the cerebrospinal fluid of PD patients. Herein, we show that the levels of CYP46A1 and 24-OHC are elevated in PD patients and increase with age in a mouse model. Overexpression of CYP46A1 intensifies α-Syn pathology, whereas genetic removal of CYP46A1 attenuates α-Syn neurotoxicity and nigrostriatal dopaminergic degeneration in the brain. Moreover, supplementation with exogenous 24-OHC exacerbates the mitochondrial dysfunction induced by α-Syn fibrils. Intracerebral injection of 24-OHC enhances the spread of α-Syn pathology and dopaminergic neurodegeneration via elevated X-box binding protein 1 (XBP1) and lymphocyte-activation gene 3 (LAG3) levels. Thus, elevated CYP46A1 and 24-OHC promote neurotoxicity and the spread of α-Syn via the XBP1‒LAG3 axis. Strategies aimed at inhibiting the CYP46A1-24-OHC axis and LAG3 could hold promise as disease-modifying therapies for PD.
2025-01-23 | MTBLS11709 | MetaboLights
Project description:Proteinaceous aggregates containing alpha-synuclein protein called Lewy bodies in the substantia nigra is a hallmark of Parkinson's disease. The molecular mechanisms of Lewy body formation and associated neuronal loss remain largely unknown. To gain insights on proteins and pathways associated with Lewy body pathology, we performed quantitative profiling of the proteome. We analyzed substantia nigra tissue from 51 subjects arranged into three groups: cases with Lewy body pathology, Lewy body-negative controls with matching neuronal loss and controls with no neuronal loss. Using label-free LC-MS/MS approach we quantified the 2,963 most abundant proteins. Statistical testing for differential protein abundance, followed by pathway enrichment and Bayesian learning of the causal network structure were performed to identify likely drivers of Lewy body formation and dopaminergic neuronal loss. The identified pathways include (1) Arp2/3 complex-mediated actin nucleation; (2) synaptic function; (3) poly(A) RNA binding; (4) basement membrane and endothelium; and (5) hydrogen peroxide metabolic process. According to the data, the endothelial/basement membrane pathway is tightly connected with both pathologies and likely to be one of the drivers of the neuronal loss. The poly(A) RNA-binding proteins, including the ones relevant to other neurodegenerative disorders (e.g. TDP-43 and FUS) have strong inverse correlation with Lewy bodies and may reflect alternative mechanism of nigral neurodegeneration.
2022-08-11 | PXD019279 | Pride
Project description:Progression through neuronal loss of substantia nigra pars compacta with Parkinson’s disease depends on various protein post-translational modifications mainly comprising phosphorylation, ubiquitination, acetylation, and methylation. Phosphorylation and ubiquitination regulate major physiological changes and cellular signaling pathways during dopaminergic neuronal death. Phosphorylation and ubiquitination dyshomeostasis of substantia nigra pars compacta tissue occurs earlier than movement symptom appearance. Although many phosphorylation and ubiquitination sites have been identified through site-specific methods, systematic quantitative proteomic analysis of pre-symptomatic Parkinson’s disease remains unexplored. Using quantitative proteomics, we have globally profiled ubiquitination and phosphorylation in substantia nigra pars compacta tissue of a Parkinson’s disease transgenic mouse model (A30P*A53T α-synuclein, hm2α-SYN-39 mouse strain) at pre-symptomatic stage; Our datasets of 5,351 phosphorylation sites in 2,136 proteins and 3,971 ubiquitination sites in 1,595 proteins provide valuable insight into pre-symptomatic Parkinson’s disease. After in-depth analysis of the relationship between phosphorylation and ubiquitination sites, we concluded that correlation of the relationship increased with decreasing distance. Subsequent bioinformatic analyses, including gene ontology annotation, domain annotation, subcellular localization, KEGG pathway annotation, functional cluster analysis, and motif analysis were performed to annotate quantifiable targets of phosphorylation and ubiquitination sites. Individual simultaneous phosphorylation and ubiquitination proteins that were differentially quantified were screened. The endocytosis pathway is likely regulated by both phosphorylation and ubiquitination at the molecular protein Epn2 (S439 and K135) in early-stage Parkinson’s disease. Therefore, this elucidation of the dysregulation of phosphorylation and ubiquitination has implications for understanding the pathophysiological mechanism of dopaminergic neuron degeneration and for developing novel therapeutics for Parkinson’s disease.
2022-02-28 | PXD013965 | Pride
Project description:Analysis of human dopamine (DA) from postmortem brains of 8 patients with Parkinson’s disease (PD). Results provide insight into the molecular processes perturbed in the PD substantia nigra.
2011-01-20 | GSE24378 | GEO