PFF induce LRRK2-Mediated Rab5 Phosphorylation Triggering Lysosomal Dysfunction and Neuronal Senescence [RNA-Seq]
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE294140 | GEO | 2026/05/13
REPOSITORIES: GEO
Similar Datasets
Project description:While there is significant progress in characterizing the pathogenesis of Parkinson's disease (PD), underlying cell biological events are less well-defined. Increasing evidence suggests that endolysosomal dysfunction is a critical driver of PD pathogenesis. In this study, we explored the impact of preformed α-synuclein fibrils (PFF) on endolysosomal function and downstream events, including activation of cellular senescence pathways. We found that PFF treatment of primary cultures of mouse cortical neurons caused widespread endolysosomal dysfunction. PFF treatment also induced changes in transcriptional reprogramming and chromatin accessibility. To define underlying mechanisms we explored the status of LRRK2, finding that PFF treatment activated LRRK2 on early endosomes where it phosphorylated Rab5. PFF also induced phosphorylation of Rab7. LRRK2 activation was necessary for endolysosomal dysfunction and transcriptional changes as these changes were prevented by pharmacological inhibition of LRRK2 with MLi-2. In addition, Rab5 changes mediated by PFF treatment contributed to changes in chromatin remodeling. These cell biological insights point to a critical role in PD pathogenesis for LRRK2 activation and its engagement of the endolysosomal network and to a novel role for the LRRK2-Rab5 axis in mediating its manifestations.
2026-05-13 | GSE294156 | GEO
Project description:Parkinson’s disease (PD) is characterized by neuroinflammation, progressive loss of dopaminergic neurons, and accumulation of a-synuclein (a-Syn) into insoluble aggregates called Lewy pathology. The Line 61 a-Syn mouse is an established preclinical model of PD; Thy-1 is used to promote human a-Syn expression, and features of sporadic PD develop at 9-18 months of age. To accelerate the PD phenotypes, we injected sonicated human a-Syn preformed fibrils (PFFs) into the striatum, which produced phospho-Syn (p-a-Syn) inclusions in the substantia nigra pars compacta and significantly increased MHC Class II-positive immune cells. Additionally, there was enhanced infiltration and activation of innate and adaptive immune cells in the midbrain. We then used this new model, Line 61-PFF, to investigate the effect of inhibiting the JAK/STAT signaling pathway, which is critical for regulation of innate and adaptive immune responses. After administration of the JAK1/2 inhibitor AZD1480, immunofluorescence staining showed a significant decrease in p-a-Syn inclusions and MHC Class II expression. Flow cytometry showed reduced infiltration of CD4+ T-cells, CD8+ T-cells, CD19+ B-cells, dendritic cells, macrophages, and endogenous microglia into the midbrain. Importantly, single-cell RNA-Sequencing analysis of CD45+ cells from the midbrain identified 9 microglia clusters, 5 monocyte/macrophage (MM) clusters, and 5 T-cell (T) clusters, in which potentially pathogenic MM4 and T3 clusters were associated with neuroinflammatory responses in Line 61-PFF mice. AZD1480 treatment reduced cell numbers and cluster-specific expression of the antigen-presentation genes H2-Eb1, H2-Aa, H2-Ab1, and Cd74 in the MM4 cluster and proinflammatory genes such as Tnf, Il1b, C1qa, and C1qc in the T3 cluster. Together, these results indicate that inhibiting the JAK/STAT pathway suppresses the activation and infiltration of innate and adaptive cells, reducing neuroinflammation in the Line 61-PFF mouse model.
2024-05-31 | GSE264525 | GEO
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:We conducted proteomic and phosphoproteomic profiling of two widely used Parkinson’s disease (PD) mouse models: the neurotoxin-based MPTP model and the α-synuclein preformed fibril (PFF) inoculation model. Tissues from substantia nigra and cerebellum were collected for multi-omics analysis to uncover region-specific protein expression and phosphorylation changes associated with PD pathogenesis.
2025-06-16 | PXD065072 |
Project description:Synucleinopathies are age-related neurological disorders which include dementia with Lewy bodies (DLB), Parkinson’s disease (PD), and multiple system atrophy (MSA). The diseases are characterized by the abnormal deposition and aggregation of a-synuclein and neuroinflammation. Recent studies have demonstrated the existence of structurally distinct a-synuclein aggregates in this group of the diseases. While the correlation between specific forms of a-synuclein and distinct pathological characteristics has been extensively studied, their relationship to neuroinflammation remains elusive. Here, we examined the effects of structurally distinct a-synuclein polymorphs on microglial neuroinflammation. Human induced pluripotent stem cells (iPSCs)-derived microglia (iMicroglia) were treated with a-synuclein polymorphs including EGCG stabilized a-synuclein oligomers (EO), kinetically stable a-synuclein oligomers (KSO), dopamine stabilized a-synuclein oligomers (DO), a-synuclein preformed fibrils (PFF), sonicated a-synuclein preformed fibrils (sPFF), and matured a-synuclein fibrils (Fib). Microglial gene expressions were accessed by transcriptome analysis and Toll-like receptor agonist activities were determined by HEK-Blue TLR reporter assay. Exposures to kinetically stable a-synuclein oligomers and matured a-synuclein fibrils induced the expression of microglial cytokines and chemokines, while other species did not. Microglial transcriptome analysis yielded that all polymorphs commonly induce toll-like receptor (TLR) signaling cascade despite differential transcriptomic phenotypes. Among structurally distinct a-synuclein polymorphs, live cell TLR reporter assay showed that kinetically stable a-synuclein oligomers induce the activities of TLR2 and 4, and sonicated a-synuclein preformed fibril TLR4, relative to the control. These results suggest that structurally distinct a-synuclein polymorphs have likewise distinct neuroinflammatory properties.
2026-01-21 | GSE305401 | GEO
Project description:Lewy body inclusions enriched with aggregated forms of the presynaptic protein alpha-synuclein (aSyn) are a hallmark of synucleinopathy diseases such as Parkinson's disease (PD) and dementia with Lewy bodies (DLB). To model this pathology, C57 mice were injected in the cortex or striatum with preformed fibrils (PFFs) prepared from mouse aSyn to induce the aggregation of the endogenous mouse protein. Monomeric aSyn was injected as a control. Aggregated aSyn was detected via immunohistochemical staining in the sensorimotor cortex at 1- and 3-months post-injection in PFF-injected mice, but not monomer-injected animals. Phosphoproteomics analysis was carried out on homogenates from the sensorimotor cortex of mice inoculated with PFFs or monomer, 3 months post-injection, and the data are presented here.
2024-11-25 | PXD058091 | Pride
Project description:Alpha-Synuclein (α-Syn) association with exosomes has been extensively studied both as a physiological process but also as a means of disease transmission under pathological conditions, via an elusive mechanism. Here, we utilized the preformed fibril (PFF) mouse model, as a source of brain-derived exosomes and assessed their pathogenic capacity following intrastriatal injections in host wild type (WT) mouse brain. We further investigated the impact of PFF toxic stimulus in the exosomal cargo independent of the endogenous α-Syn, by isolating exosomes from PFF-injected α-Syn knockout mice. We found that PFF inoculation does not alter the morphology, size distribution, and quantity of brain-derived exosomes, however we show, for the first time, that it triggers changes in the exosomal protein cargo related to synaptic and mitochondrial function, as well as metabolic processes. Importantly, we showed that the presence of the endogenous α-Syn is essential for the exosomes to acquire a pathogenic identity/status, allowing them to mediate disease transmission by inducing phospho-α-Syn pathology, astrogliosis and synaptic alterations in the host mouse brain, thus supporting a role of exosomes in a prion-like mode of infection.
2023-08-04 | PXD036301 | Pride
Project description:Parkinson’s disease (PD) is a neurodegenerative disorder characterized by a loss of dopaminergic neurons. Recent studies suggested the association of zinc finger protein 184 (ZNF184) with PD. However, the functional role of ZNF184 in PD pathogenesis remains unclear. Therefore, we aimed to confirm this association and the effects of ZNF184 in a mouse model of PD and human patients with PD.We found that ZNF184 levels were decreased in the substantia nigra (SN) of α-synuclein preformed fibril (α-syn PFF)-injected mice and cells treated with PD toxins. Furthermore, ZNF184 was reduced in the cortex and SN of patients with PD, suggesting an association between ZNF184 and PD pathogenesis. In ZNF184-overexpressing cells, RNA-sequencing analysis revealed significant alterations in several protein-coding genes including interleukin enhancer binding factor 3 (ILF3). Bioinformatic analysis identified potential ZNF184 binding motifs within the ILF3 promoter, and ZNF184 occupancy was confirmed. Since ILF3 inhibits the biogenesis of microRNA-7 (miR-7), which regulates α-synuclein aggregation, we administered the miR-7 inducer, scutellarin to α-syn PFF-injected mice, preventing dopaminergic neuron and reinstating motor abilities. Our findings suggest that ZNF184 promotes miR-7 upregulation by suppressing ILF3 transcription, revealing a novel pathway that could serve as a promising therapeutic target for the treatment of PD.
2024-11-20 | GSE282345 | GEO
Project description:Synucleinopathies are triggered by the aggregation of α-synuclein (αSyn), leading to progressive neurodegeneration. However, the intracellular mechanism of αSyn aggregation remains unclear. Here we show that assembly of RNA G-quadruplexes (rG4s) form scaffolds for αSyn aggregation, contributing to neurodegeneration. Purified αSyn binds rG4s directly through the N-terminus. rG4 itself undergoes phase separation and assembly by Ca2+, accelerating the sol-gel phase transition of αSyn. In αSyn preformed fibrils (PFF)-treated neurons, rG4s assembly composed of synaptic mRNAs co-aggregates with αSyn upon Ca2+ excess influx into cytoplasm, eliciting synaptic dysfunction. Artificial assembly of rG4s using an optogenetic approach evokes αSyn aggregation and neuronal dysfunction. Administration of 5-aminolevulinic acid (5-ALA), a prodrug of protoporphyrin IX (PpIX) that prevents phase separation of rG4s, attenuating αSyn aggregation, neurodegeneration, and progressive motor deficits in PFF-injected synucleinopathy mice. Together, assembly of rG4s due to dysregulation of intracellular Ca2+ homeostasis accelerates αSyn phase transition and aggregation may contribute to pathogenesis of synucleinopathies.
2023-07-18 | GSE234238 | GEO
Project description:Brain aggregates of α-synuclein (α-syn) characterizes a group of diseases defined as synucleinopathies. Recent studies implicate neuroinflammation as one of the central pathogenic mechanisms. However, how inflammation is linked to the α-syn pathology is still unknown. We wanted to address this by a ‘double-hit’ approach. Three weeks after intra-striatal injections of human α-syn pre-formed fibrils (PFF), mice were subjected for 3 weeks to repeated intraperitoneal injections of low concentrations (1 mg/ml) of lipopolysaccharide (LPS), a component of gram-negative bacteria. Histological analysis confirmed brain propagation of α-syn aggregation in PFF-injected mice independent of LPS-injections. No motor dysfunction was observed at this stage as measured in the pole test. Spleen immune cell profiling and multiplex cytokine analysis confirmed LPS-induced changes in T- and B-cells populations, monocytes, and neutrophils, and increased brain TNF-α, IL-β, IL-10 and KC/GRO levels. LC-MS/MS analysis in the forebrain area and subsequent downstream ReactomeGSA pathway analysis revealed that PFF-injections induced alterations in mitochondrial metabolism and neurotransmitter signaling. Systemic inflammation resulted in an overrepresentation of complement and coagulation pathways and upregulation of integrin and B cell receptor signaling in the PFF-injected mice.
2024-09-05 | PXD039193 | Pride