Subtyping Lewy body disorders using proteomics
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Orbitrap Fusion Lumos
ORGANISM(S): Homo Sapiens (human)
TISSUE(S): Brain
DISEASE(S): Parkinson's Disease
SUBMITTER: 
Ivan Martinez-Valbuena
LAB HEAD: Ivan Martinez
PROVIDER: PXD034441 | Pride | 2022-07-20
REPOSITORIES: Pride
Similar Datasets
Project description:Parkinson’s disease (PD) is characterized by the accumulation of misfolded and aggregated alpha-synuclein (α-syn) into intraneuronal inclusions named Lewy bodies (LB). Although it is widely believed that α-syn plays a central role in the pathogenesis of PD, the processes that govern α-syn fibrillization and LB formation remain poorly understood. In this work, we sought to dissect the spatiotemporal events involved in the biogenesis of the LBs at the genetic, molecular, biochemical, structural, and cellular levels. Towards this goal, we further developed a seeding-based model of α-syn fibrillization to generate a neuronal model that reproduces all the key events leading to LB formation; including seeding, fibrillization, and the formation of inclusions that recapitulate many of the biochemical, structural, and organizational features of bona fide LBs. Using an integrative omics, biochemical and imaging approach, we dissected the molecular events associated with the different stages of LB formation and their contribution to neuronal dysfunction and degeneration. In addition, we demonstrate that LB formation involves a complex interplay between α-syn fibrillization, post-translational modifications, and interactions between α-syn aggregates and membranous organelles, including mitochondria, the autophagosome and endolysosome. Finally, we show that the process of LB formation, rather than simply fibril formation, is the major driver of neurodegeneration through disruption of cellular functions and inducing mitochondria damage and deficits, and synaptic dysfunctions. We believe that this model represents a powerful platform to further investigate the mechanisms of LB formation and clearance and to screen and evaluate novel therapeutics targeting α-syn aggregation and LB formation.
2020-01-15 | GSE142416 | GEO
Project description:Parkinson’s disease (PD) is characterized by the accumulation of misfolded and aggregated alpha-synuclein (α-syn) into intraneuronal inclusions named Lewy bodies (LB). Although it is widely believed that α-syn plays a central role in the pathogenesis of PD, the processes that govern α-syn fibrillization and LB formation remain poorly understood. In this work, we sought to dissect the spatiotemporal events involved in the biogenesis of the LBs at the genetic, molecular, biochemical, structural, and cellular levels. Towards this goal, we further developed a seeding-based model of α-syn fibrillization to generate a neuronal model that reproduces all the key events leading to LB formation; including seeding, fibrillization, and the formation of inclusions that recapitulate many of the biochemical, structural, and organizational features of bona fide LBs. Using an integrative omics, biochemical and imaging approach, we dissected the molecular events associated with the different stages of LB formation and their contribution to neuronal dysfunction and degeneration. In addition, we demonstrate that LB formation involves a complex interplay between α-syn fibrillization, post-translational modifications, and interactions between α-syn aggregates and membranous organelles, including mitochondria, the autophagosome and endolysosome. Finally, we show that the process of LB formation, rather than simply fibril formation, is the major driver of neurodegeneration through disruption of cellular functions and inducing mitochondria damage and deficits, and synaptic dysfunctions. We believe that this model represents a powerful platform to further investigate the mechanisms of LB formation and clearance and to screen and evaluate novel therapeutics targeting α-syn aggregation and LB formation.
2020-01-15 | PXD016850 | Pride
Project description:The glucocorticoid receptor (GR) is a ubiquitously expressed transcription factor that controls metabolic and homeostatic processes essential for life. Although numerous crystal structures of the GR ligand-binding domain (GR-LBD) have been reported, the functional oligomeric state of the full-length receptor, which is essential for its transcriptional activity, remains disputed. Here we present five new crystal structures of agonist-bound GR-LBD, along with a thorough analysis of previous structural work. Biologically relevant homodimers were identified by studying a battery of GR point mutants including crosslinking assays in solution and quantitative fluorescence microscopy in live cells. Our results highlight the relevance of non-canonical dimerization modes for GR, especially of contacts made by loop L1-3 residues such as Tyr545. Our work unveils likely pathophysiologically relevant quaternary assemblies of the nuclear receptor with important implications for glucocorticoid action and drug design.
2023-03-11 | PXD028039 | Pride
Project description:Parkinson’s disease (PD) is a neurodegenerative disease characterized by progressive motor symptoms and alpha-synuclein (αsyn) aggregation in the nervous system. For unclear reasons, PD patients with certain GBA mutations (GBA-PD) have a more aggressive clinical progression. Two testable hypotheses that can potentially account for this phenomenon are that GBA1 mutations promote αsyn spread or drive the generation of highly pathogenic αsyn polymorphs (i.e., strains). We tested these hypotheses by treating homozygous GBA1 D409V knockin (KI) mice with human α-syn-preformed fibrils (PFFs) and treating wild-type mice (WT) with several αsyn-PFF polymorphs amplified from brain autopsy samples collected from patients with idiopathic PD and GBA-PD patients with either homozygous or heterozygous GBA1 mutations. Robust phosphorylated-αsyn (PSER129) positive pathology was observed at the injection site (i.e., the olfactory bulb granular layer) and throughout the brain six months following PFF injection. The PFF seeding efficiency and degree of spread were similar regardless of the mouse genotype or PFF polymorphs. We found that PFFs amplified from the human brain, regardless of patient genotype, were generally more effective seeders than wholly synthetic PFFs (i.e., non-amplified); however, PFF concentration differed between these two studies, and this might also account for the observed differences. To investigate whether the molecular composition of pathology differed between different seeding conditions, we permed Biotinylation by Antibody Recognition on PSER129 (BAR-PSER129). We found that for BAR-PSER129, the endogenous PSER129 pool dominated identified interactions, and thus, very few potential interactions were explicitly identified for seeded pathology. However, we found Dctn2 interaction was shared across all PFF conditions, and Nckap1 and Ap3b2 were unique to PFFs amplified from GBA-PD brains of heterozygous mutation carriers. In conclusion, both the genotype and αsyn strain had little effect on overall seeding efficacy and global PSER129-interactions.
2024-02-22 | PXD045437 | Pride
Project description:Parkinson disease (PD) is closely linked to the misfolding and accumulation of α-synuclein (α-syn) into Lewy bodies. HtrA1 is a PDZ serine protease that degrades fibrillar tau, which is associated with Alzheimer disease (AD). Further, inactivating mutations to mitochondrial HtrA2 have been implicated in PD. Here, we establish that HtrA1 inhibits the aggregation of α-syn as well as FUS and TDP-43, which are implicated in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). We demonstrate that the protease domain of HtrA1 is necessary and sufficient for inhibition of aggregation, yet this activity is independent of HtrA1 proteolytic activity. Further, we find that HtrA1 also disaggregates preformed α-syn fibrils, which may promote their clearance. Treatment of α-syn fibrils with HtrA1 renders α-syn incapable of seeding the aggregation of endogenous α-syn in mammalian biosensor cells. We find that HtrA1 remodels α-syn by specifically targeting the NAC domain, which is the key domain that catalyzes α-syn oligomerization and fibrillization. Finally, in a primary neuron model of α-syn aggregation, we show that HtrA1 and its proteolytically inactive form both detoxify α-syn and prevent the formation of hyperphosphorylated α-syn accumulations. Our findings suggest that HtrA1 prevents aggregation and promotes disaggregation of multiple disease-associated proteins, and may be a therapeutic target for treating a range of neurodegenerative disorders.
2024-02-20 | PXD041784 | JPOST Repository
Project description:Parkinson disease (PD) is closely linked to the misfolding and accumulation of α-synuclein (α-syn) into Lewy bodies. HTRA1 is a PDZ serine protease that degrades fibrillar tau, which is associated with Alzheimer disease (AD). Further, inactivating mutations to mitochondrial HTRA2 have been implicated in PD. Here, we establish that HTRA1 inhibits the aggregation of α-syn as well as FUS and TDP-43, which are implicated in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). We demonstrate that the protease domain of HTRA1 is necessary and sufficient for inhibition of aggregation, yet this activity is independent of HTRA1 proteolytic activity. Further, we find that HTRA1 also disaggregates preformed α-syn fibrils, which may promote their clearance. Treatment of α-syn fibrils with HTRA1 renders α-syn incapable of seeding the aggregation of endogenous α-syn in mammalian biosensor cells. We find that HTRA1 remodels α-syn by specifically targeting the NAC domain, which is the key domain that catalyzes α-syn oligomerization and fibrillization. Finally, in a primary neuron model of α-syn aggregation, we show that HTRA1 and its proteolytically inactive form both detoxify α-syn and prevent the formation of hyperphosphorylated α-syn accumulations. Our findings suggest that HTRA1 prevents aggregation and promotes disaggregation of multiple disease-associated proteins, and may be a therapeutic target for treating a range of neurodegenerative disorders.
2024-02-20 | PXD044806 | JPOST Repository
Project description:Aggregated alpha-synuclein (α-syn) is a principal constituent of Lewy bodies (LBs) and glial cytoplasmic inclusions (GCIs) that are observed respectively inside neurons in Parkinson’s disease (PD) and oligodendrocytes in multiple system atrophy (MSA). Yet, the cellular origin, the exact pathophysiological role, and the mechanism of formation of these inclusions remain to be elucidated. It has recently been proposed that pathological α-syn inclusions are capable of eventually causing the demise of the host cell by virtue of the cumulative sequestration of partner proteins and organelles. In particular, the hypothesis of a local cross-seeding of other fibrillization-prone proteins like tau or TDP-43 has also been put forward. The objective of this study was to examine the composition of these inclusions to gain insight into their origin and mechanisms of formation. We submitted total solubilized and sarkosyl-insoluble extracts of post-mortem brain tissue from PD and MSA patients and control subjects to a comparative proteomic analysis to address these points. In parallel, we used proteomics for α-syn quantification in total solubilized brain homogenates and the respective sarkosyl-insoluble pellets as an unbiased validation of our results obtained by immunoblotting of these samples and fractions.
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Project description:Aggregated alpha-synuclein (α-syn) is a principal constituent of Lewy bodies (LBs) and glial cytoplasmic inclusions (GCIs) that are observed respectively inside neurons in Parkinson’s disease (PD) and oligodendrocytes in multiple system atrophy (MSA). Yet, the cellular origin, the exact pathophysiological role, and the mechanism of formation of these inclusions remain to be elucidated. It has recently been proposed that pathological α-syn inclusions are capable of eventually causing the demise of the host cell by virtue of the cumulative sequestration of partner proteins and organelles. In particular, the hypothesis of a local cross-seeding of other fibrillization-prone proteins like tau or TDP-43 has also been put forward. The objective of this study was to examine the composition of these inclusions to gain insight into their origin and mechanisms of formation. We submitted sarkosyl-insoluble extracts of post-mortem brain tissue from PD and MSA patients and control subjects to a comparative proteomic analysis to address these points.
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Project description:Alpha-synuclein (α-syn) aggregation and immune activation represent hallmark pathological events in Parkinson’s disease (PD). The PD-associated immune response encompasses both brain and peripheral immune cells, although little is known about the immune proteins relevant for such response. We propose that the upregulation of CD163 observed in blood monocytes and in the responsive microglia in the PD patients is a protective mechanism in the disease. To investigate this, we used the PD model based on intrastriatal injections of murine α-syn pre-formed fibrils (PFF) in CD163 knockout (KO) mice and wild-type littermates. CD163KO females revealed an impaired and differential early immune response to α-syn pathology as revealed by immunohistochemical and transcriptomic analysis. After 6 months, CD163KO females showed an exacerbated immune response and α-syn pathology, which ultimately led to a dopaminergic neurodegeneration of greater magnitude. These findings support a novel, sex-dimorphic neuroprotective role for CD163 during α-syn-induced neurodegeneration.
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