MiR-101a-3p impairs synaptic plasticity and contributes to synucleinopathy
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE196020 | GEO | 2023/02/02
REPOSITORIES: GEO
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Project description:BackgroundSynucleinopathies are disorders characterized by the abnormal accumulation of α-synuclein (aSyn). Synaptic compromise is observed in synucleinopathies parallel to aSyn aggregation and is accompanied by transcript deregulation.ObjectiveWe sought to identify microRNAs associated with synaptic processes that may contribute to synaptic dysfunction and degeneration in synucleinopathies.MethodsWe performed small RNA-sequencing of midbrain from 6-month-old transgenic mice expressing A30P mutant aSyn, followed by comparative expression analysis. We then used real-time quantitative polymerase chain reaction (qPCR) for validation. Functional analysis was performed in primary neurons by biochemical assays and imaging.ResultsWe found several deregulated biological processes linked to the synapse. miR-101a-3p was validated as a synaptic miRNA upregulated in aSyn Tg mice and in the cortex of dementia with Lewy bodies patients. Mice and primary cultured neurons overexpressing miR-101a-3p showed downregulation of postsynaptic proteins GABA Ab2 and SAPAP3 and altered dendritic morphology resembling synaptic plasticity impairments and/or synaptic damage. Interestingly, primary cultured neuron exposure to recombinant wild-type aSyn species efficiently increased miR-101a-3p levels. Finally, a dynamic role of miR-101a-3p in synapse plasticity was shown by identifying downregulation of miR-101a-3p in a condition of enhanced synaptic plasticity modelled in Wt animals housed in enriched environment.ConclusionTo conclude, we correlated pathologic aSyn with high levels of miR-101a-3p and a novel dynamic role of the miRNA in synaptic plasticity.
| S-EPMC10041420 | biostudies-literature
Project description:miR-101a-3p impairs synaptic plasticity and contributes to synucleinopathy
| PRJNA803028 | ENA
Project description:Alpha-synuclein (aSyn) is a central player in the pathogenesis of synucleinopathies due to its accumulation in typical protein aggregates in the brain. However, it is still unclear how it contributes to neurodegeneration. Type-2 diabetes mellitus is a risk factor for Parkinson’s disease (PD) and, interestingly, a common molecular alteration among these disorders is the age-associated increase in protein glycation. We hypothesized that glycation-induced neuronal dysfunction might be a contributing factor in synucleinopathies. Here, we dissected the specific impact of methylglyoxal (MGO, a glycating agent) in mice overexpressing aSyn in the brain. We found that MGO-glycation potentiates motor, cognitive, olfactory, and colonic dysfunction in aSyn transgenic (Thy1-aSyn) mice that received a single dose of MGO via intracerebroventricular (ICV) injection. aSyn accumulates in the midbrain, striatum, and prefrontal cortex, and protein glycation is increased in the cerebellum and midbrain. SWATH mass spectrometry analysis, used to quantify changes in the brain proteome, revealed that MGO mainly increase glutamatergic-associated proteins in the midbrain (NMDA, AMPA, glutaminase, VGLUT and EAAT1), but not in the prefrontal cortex, where it mainly affects the electron transport chain. Notably, the glycated proteins in the midbrain of Thy1-aSyn mice that received MGO strongly correlate with PD and dopaminergic pathways. Overall, we demonstrated that MGO-induced glycation accelerates PD-like sensorimotor and cognitive alterations and suggest that the increase of glutamatergic signaling may underly these events. Our study sheds new light into the enhanced vulnerability of the midbrain in PD-related synaptic dysfunction and suggests that glycation suppressors and anti-glutamatergic drugs may hold promise as disease-modifying therapies for synucleinopathies.
2022-05-20 | PXD032832 | Pride
Project description:The accumulation of α-synuclein (ASyn) has been observed in several lysosomal storage diseases (LSD), but it remains unclear if the accumulation of ASyn contributes to the pathology. The mitochondria degeneration, reduced expression of manganese superoxide dismutase 2, and reactive oxygen species-mediated oxidative damage were observed in the neurons of Hexb-/- mice. Gene expression in the brain of 14-week-old Hexb-/- ASyn+/+, Hexb-/- Asyn-Tg, and Hexb-/- ASyn-/- mice were analyzed.
2015-05-12 | E-GEOD-68748 | biostudies-arrayexpress
Project description:Effect of Gpnmb knockout on development of differential expression in PFF-aSyn model was studied. The "sample_id" sample characteristic is a sample identifier internal to Genentech. The ID of this project in Genentech's ExpressionPlot database is PRJ0036142
2021-06-18 | GSE163727 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2014-07-01 | E-GEOD-47848 | biostudies-arrayexpress
Project description:Jaundice is one of the most common problems encountered in newborn infants, due to immaturity of hepatic conjugation and transport processes for bilirubin. Although the majority of neonatal jaundice is benign, some neonates with severe hyperbilirubinemia develop bilirubin encephalopathy or kernicterus. Accumulation of unconjugated bilirubin (UCB) in selected brain regions may result in temporary or permanent impairments of auditory, motor, or cognitive function; however, the molecular mechanisms by which UCB elicits such neurotoxicity are still poorly understood. The present study is undertaken to investigate whether prolonged exposure of rat organotypic hippocampal slice cultures to UCB alters the induction of long-term synaptic plasticity.Using electrophysiological recording techniques, we find that exposure of hippocampal slice cultures to clinically relevant concentrations of UCB for 24 or 48 h results in an impairment of CA1 long-term potentiation (LTP) and long-term depression (LTD) induction in a time- and concentration-dependent manner. Hippocampal slice cultures stimulated with UCB show no changes in the secretion profiles of the pro-inflammatory cytokines, interleukin-1beta and tumor necrosis factor-alpha, or the propidium ioide uptake. UCB treatment produced a significant decrease in the levels of NR1, NR2A and NR2B subunits of N-methyl-D-aspartate (NMDA) receptors through a calpain-mediated proteolytic cleavage mechanism. Pretreatment of the hippocampal slice cultures with NMDA receptor antagonist or calpain inhibitors effectively prevented the UCB-induced impairment of LTP and LTD.Our results indicate that the proteolytic cleavage of NMDA receptor subunits by calpain may play a critical role in mediating the UCB-induced impairment of long-term synaptic plasticity in the hippocampus. These observations provide new insights into the molecular mechanisms underlying UCB-induced impairment of hippocampal synaptic plasticity which, in turn, might provide opportunities for the development of novel therapeutic strategies that targets these pathways for treatment.
| S-EPMC2690688 | biostudies-other
Project description:Mitochondrial dysfunction plays a central role in the pathogenesis of neurodegenerative diseases such as Parkinson’s disease (PD). This study tested the hypothesis that the dipeptide carnosine would exert a beneficial effect in the Thy1-aSyn mouse model of PD, which displays mitochondrial dysfunction. Mitochondrial function and gene expression were evaluated in the midbrain after two months of carnosine administration by intranasal (IN) or drinking water routes of exposure. IN carnosine attenuated transcriptional changes in the midbrain in Thy1-aSyn mice. Additionally, IN-carnosine increased expression of mitochondria complexes and enhanced mitochondrial function, suggesting a potential neuroprotective role for IN-carnosine in PD.
2018-12-31 | GSE115769 | GEO
Project description:Adult neurogenesis is a process by which the brain produces new neurons once development has ceased. Adult hippocampal neurogenesis has been linked to the relational processing of spatial information, a role attributed to the contribution of newborn neurons to long-term potentiation (LTP). However, whether newborn neurons also influence long-term depression (LTD), and how synaptic transmission and plasticity are affected as they incorporate their network, remain to be determined. To address these issues, we took advantage of a genetic model in which a majority of adult-born neurons can be selectively ablated in the dentate gyrus (DG) and, most importantly, in which neurogenesis can be restored on demand. Using electrophysiological recordings, we show that selective reduction of adult-born neurons impairs synaptic transmission at medial perforant pathway synapses onto DG granule cells. Furthermore, LTP and LTD are largely compromised at these synapses, probably as a result of an increased induction threshold. Whereas the deficits in synaptic transmission and plasticity are completely rescued by restoring neurogenesis, these synapses regain their ability to express LTP much faster than their ability to express LTD. These results demonstrate that both LTP and LTD are influenced by adult neurogenesis. They also indicate that as newborn neurons integrate their network, the ability to express bidirectional synaptic plasticity is largely improved at these synapses. These findings establish that adult neurogenesis is an important process for synaptic transmission and bidirectional plasticity in the DG, accounting for its role in efficiently integrating novel incoming information and in forming new memories.
| S-EPMC3081011 | biostudies-literature
Project description:Cystatin B (CSTB) is a small protease inhibitor involved in cell proliferation and migration, and composition of extracellular matrix during brain development. Loss-of-function mutations in the gene encoding CSTB cause progressive myoclonic epilepsy 1 (EPM1). We previously demonstrated that CSTB is locally synthesized in the synaptosomes from rat brain and secreted into the media, indicating its role in synaptic plasticity. In this work, we further investigate the involvement of CSTB in synaptic plasticity, using synaptosomes from rodents’ brain, as well as from human Cerebral Organoids (hCOs). Our data demonstrated that CSTB is released by synaptosomes in two ways: as a soluble protein, and in extracellular vesicles-mediated manner. Synaptosomes isolated from hCOs are enriched in pre-synaptic proteins, as expected for an in vitro model of human synapses, and contain CSTB at all developmental stages analysed. However, only at late maturation stages synapse becomes physiologically active, i.e. particularly enriched with exocytosis-associated proteins. CSTB presence in the synaptic territories was confirmed also by immunostaining on human neurons in vitro. To investigate if the depletion of CSTB in EPM1 is affecting synaptic plasticity, we used synaptosomes from EPM1 hCOs. The synaptosomal levels of presynaptic proteins and of an initiation factor linked to local protein synthesis, were reduced in EPM1 hCOs compared to controls, and the extracellular vesicles trafficking was impaired. Moreover, morphological alteration was detected in neurons from EPM1 patients, indicating a connectivity deficit. In conclusion, our data indicate a significant role of synaptic CSTB in cell-to-cell communication in physiological and pathological conditions, and demonstrated that CSTB-dependent altered synaptic plasticity is one of the mechanisms underlying EPM1.
2024-08-10 | PXD041125 | Pride