Small cell lung cancer induces synaptic scaling to alter neuronal excitability
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE305403 | GEO | 2025/10/01
REPOSITORIES: GEO
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Project description:Elevated c-Jun levels result in apoptosis and are evident in neurodegenerative disorders such as Alzheimer's disease and dementia and after global cerebral insults such as stroke and epilepsy. NMDA receptor (NMDAR) antagonists block c-Jun upregulation and prevent neuronal cell death following excitotoxic insults. However, little is known about the molecular mechanisms that regulate c-Jun abundance in neurons. Here we show that PRR7, a component of synaptic junctions, can upregulate c-Jun levels by inhibiting its ubiquitination in neurons. PRR7 interacts with the GLUN1 subunit of NMDARs and is upregulated in the nucleus following NMDAR activation. We show that PRR7 interacts with the E3 ligase SCFFBW7 (FBW7) and blocks the FBW7-mediated ubiquitination of c-Jun. PRR7 overexpression increases c-Jun-dependent transcriptional activity and promotes neuronal death. Microarray assays indicate that both Prr7 knockdown or overexpression alter the abundance of c-Jun-regulated transcripts associated with cellular viability as well as synaptic function. Moreover, Prr7 knockdown attenuates NMDA-mediated excitotoxicity in primary neuronal cultures. Our results show that PRR7 links NMDAR activity to c-Jun function and provide insight into the processes that underlie NMDA-dependent excitotoxicity. Four biological replicas of each of the four conditions: NO = not transduced with virus; NT = transduced with control lentiviruses containing a non-targeting shRNA sequence; KD = transduced with lentiviruses expressing PRR7-specific shRNAs; OE= transduced with lentiviruses to overexpress PRR7.
2014-10-25 | E-GEOD-62686 | biostudies-arrayexpress
Project description:TAF15, an RNA binding protein was recently implicated in Amyotrophic Lateral Sclerosis (ALS). ALS is a fatal neurodegenerative disease. We report the identification of the conserved neuronal RNA targets of TAF15 and the assessment of the impact of TAF15 depletion on the neuronal transcriptome. Our study uncovers regulation of splicing of sets of neuronal RNAs encoding proteins with essential roles in synaptic activities including glutamergic receptors such as zeta-1 subunit of the glutamate N-methyl-D-aspartate (NMDA) receptor (Grin1). Identification of TAF15 neuronal targets using normal human brain samples and mouse neurons. Mouse background: E14Tg2a.4 wildtype cells derived from 129P2/OlaHsd.
2013-01-24 | E-GEOD-43294 | biostudies-arrayexpress
Project description:Primary cortical neurons were isolated from E15 mice and after 5 days in vitro were untreated or treated for 24 h with mesenchymal stem cell conditioned medium and then untreated or treated for a further 24 h with NMDA. Neuron gene expression was profiled and compared between the four different conditions (neurons, neurons+MSC cm, neurons+NMDA, neurons+MSC cm+NMDA) to investigate the molecular mechanisms of MSC neuroprotection. Mesenchymal stem cells (MSC) promote functional recovery in experimental models of central nervous system (CNS) pathology and are currently being tested in clinical trials for stroke, multiple sclerosis and CNS injury. Their beneficial effects are attributed to activation of endogenous CNS repair processes and immune regulation but their mechanisms of action are poorly understood. Here we investigated the neuroprotective effects of MSC in simplified MSC-neuron co-culture systems and in mice using models of glutamate excitotoxicity. MSC protected primary cortical neurons against glutamate (NMDA) receptor-induced death and conditioned medium from MSC (MSC cm), but not control NIH3T3 cells, was sufficient for this effect. MSC cm neuroprotection in mouse cortical neurons was reduced by neutralizing antibodies to bFGF and associated with altered gene expression in neurons towards an immature phenotype as well as reduced neuronal Grin1, Grin2a and Grin2b mRNA levels in response to NMDA stimulation. Further, MSC cm neuroprotection in rat retinal ganglion cells was associated with absence of glutamate-induced calcium influx. Adoptive transfer of EGFP+MSC in a mouse kainic acid seizure model reduced CA3 neuron damage and hippocampal astrocytosis and resulted in the increased expression of neuronal genes that are upregulated by MSC cm, Bmi1, Ddx4, Ezh1, in the hippocampus. These results show that MSC mediate direct neuroprotection against glutamate excitotoxicity by secreting bFGF, reducing glutamate receptor expression and function and altering neuron gene expression towards an immature pattern, and provide evidence for a link between the therapeutic effects of MSC and the activation of endogenous repair processes following CNS injury. In vitro cultures primary cortical neurons from mice were protected from glutamate excitotoxicity when pre-treated with MSC cm. Global gene expression changes induced in neurons before and after treatment with MSC cm and/or NMDA were investigated using a cDNA spotted macroarray filter. Four samples were analysed in duplicate: neurons alone (untreated), neurons+MSC cm, neurons+NMDA, neurons+MSC cm+NMDA.
2011-05-01 | E-GEOD-26279 | biostudies-arrayexpress
Project description:Neuronal networks are subject to fluctuations in both the magnitude and frequency of inputs, requiring plasticity mechanisms to stabilize network activity. Homeostatic synaptic scaling is a form of synaptic plasticity that adjusts the strength of neuronal connections up or down in response to large changes in input. Although homeostatic plasticity requires changes in gene expression, there is only limited data describing the molecular changes associated with homeostatic scaling, focusing mostly on the expression mechanisms involving glutamate receptors. The fact that neuronal networks can be scaled up (in response to reduced activity) or down (in response to enhanced activity) provides a unique opportunity to examine the molecular and proteomic response to opposite ends of the phenotypic spectrum of synaptic plasticity. Here we first demonstrate that homeostatic scaling required protein synthesis. We then examined the plasticity-induced changes in the newly-synthesized neuronal proteome of neurons to identify the landscape of proteomic changes that contribute to opposing forms of homeostatic plasticity. Cultured rat hippocampal neurons (21 DIV) underwent homeostatic upscaling or downscaling (treatments with TTX and Bicucculine, respectively). We used BONCAT (BioOrthogonal Non-Canonical Amino acid Tagging) to metabolically label, capture and identify newly-synthesized proteins, detecting and analysing 5940 newly-synthesized proteins using liquid chromatography-coupled tandem mass spectrometry and label-free quantitation. Neither up- or down-scaling produced changes in the number of different proteins translated. Rather, our findings indicate that synaptic up- and down-scaling elicit opposing translational regulation of several molecular pathways, producing targeted adjustments in the neuronal proteome. We detected ~ 300 differentially regulated proteins involved in neurite outgrowth, reorganization of nerve terminals, axon guidance and targeting, neurotransmitter transport, filopodia assembly, excitatory synapses and glutamate receptor complexes. These proteins include well-characterized mediators of synaptic plasticity, e.g. the ionotropic glutamate receptor complex that is down-regulated during down-scaling and coordinately upregulated during upscaling. We also identified differentially regulated proteins that in addition to their regulation in homeostatic plasticity, are also associated with multiple diseases and disorders, including intellectual disability, schizophrenia, epilepsy, and Parkinson’s disease.
2016-12-22 | PXD004889 | Pride
Project description:Elevated c-Jun levels result in apoptosis and are evident in neurodegenerative disorders such as Alzheimer's disease and dementia and after global cerebral insults such as stroke and epilepsy. NMDA receptor (NMDAR) antagonists block c-Jun upregulation and prevent neuronal cell death following excitotoxic insults. However, little is known about the molecular mechanisms that regulate c-Jun abundance in neurons. Here we show that PRR7, a component of synaptic junctions, can upregulate c-Jun levels by inhibiting its ubiquitination in neurons. PRR7 interacts with the GLUN1 subunit of NMDARs and is upregulated in the nucleus following NMDAR activation. We show that PRR7 interacts with the E3 ligase SCFFBW7 (FBW7) and blocks the FBW7-mediated ubiquitination of c-Jun. PRR7 overexpression increases c-Jun-dependent transcriptional activity and promotes neuronal death. Microarray assays indicate that both Prr7 knockdown or overexpression alter the abundance of c-Jun-regulated transcripts associated with cellular viability as well as synaptic function. Moreover, Prr7 knockdown attenuates NMDA-mediated excitotoxicity in primary neuronal cultures. Our results show that PRR7 links NMDAR activity to c-Jun function and provide insight into the processes that underlie NMDA-dependent excitotoxicity.
2014-10-25 | GSE62686 | GEO
Project description:Glutamate excitotoxicity plays a critical role in neurodegeneration by triggering NMDA receptorhyperactivation, leading to elevated synaptic calcium levels and subsequent neuronal cell death. Tobetter understand how glutamateaffects neurons in neurological diseases, we conducted acomprehensive analysis of molecular changes at the transcriptome and kinome levels.Our research used primary cortical cultures from rat embryos to study glutamate excitotoxicity. Non-neuronal cells,like astrocytes, typically enhance neuron tolerance to glutamate excitotoxicity. We useda neuron-rich cultured system and observed that the effects of glutamate on neurons are concentration-dependent. Intermediate doses of glutamate had significant neurotoxic effects, while high and lowdoses resulted in less cell mortality, aligning with previous findings related to calcium influx.Glutamate is known to inhibit protein synthesis in neurons and leads to a rise in cytosolic calcium, a keystep in synapticplasticity and delayed neuronal cell death. Kinome profiling indicated activation of PKAand PKG phosphorylation, essential for synaptic plasticity-related gene expression.
2024-05-28 | GSE255041 | GEO
Project description:Neural activity is increasingly recognized as a crucial regulator of cancer growth. In the brain, neuronal activity robustly influences glioma growth both through paracrine mechanisms and through electrochemical integration of malignant cells into neural circuitry via neuron-to-glioma synapses. Outside of the CNS, innervation of tumors such as prostate, breast, pancreatic and gastrointestinal cancers by peripheral nerves similarly regulates cancer progression. However, the extent to which the nervous system regulates lung cancer progression, either in the lung or when metastatic to brain, is less well understood. Small cell lung cancer (SCLC) is a lethal high-grade neuroendocrine tumor that exhibits a strong propensity to metastasize to the brain. Here we demonstrate that SCLC cells in the brain co-opt neuronal activity-regulated mechanisms to stimulate growth and progression. Glutamatergic and GABAergic cortical neuronal activity each drive proliferation of SCLC in the brain through both paracrine and synaptic neuron-cancer interactions. In the brain, SCLC cells form bona fide neuron-to-SCLC synapses and exhibit depolarizing currents with consequent calcium transients in response to neuronal activity. SCLC cell membrane depolarization is sufficient to promote the growth of intracranial tumors. In the lung, vagus nerve transection markedly inhibits primary lung tumor formation and development, highlighting a critical role for innervation in overall SCLC growth. Taken together, these studies illustrate that neuronal activity plays a crucial role in dictating SCLC pathogenesis in both the lung and the brain.
2025-07-29 | GSE262422 | GEO
Project description:Neural activity is increasingly recognized as a crucial regulator of cancer growth. In the brain, neuronal activity robustly influences glioma growth both through paracrine mechanisms and through electrochemical integration of malignant cells into neural circuitry via neuron-to-glioma synapses. Outside of the CNS, innervation of tumors such as prostate, breast, pancreatic and gastrointestinal cancers by peripheral nerves similarly regulates cancer progression. However, the extent to which the nervous system regulates small cell lung cancer progression, either in the lung or when growing within the brain, is less well understood. Small cell lung cancer (SCLC) is a lethal high-grade neuroendocrine tumor that exhibits a strong propensity to metastasize to the brain. Here we demonstrate that SCLC cells in the brain co-opt neuronal activity-regulated mechanisms to stimulate growth and progression. In the lung, vagus nerve transection markedly inhibits primary lung tumor formation and development, highlighting a critical role for innervation in SCLC growth. In the brain, glutamatergic and GABAergic cortical neuronal activity each drive proliferation of SCLC in the brain through both paracrine and synaptic neuron-cancer interactions. SCLC cells form bona fide neuron-to-SCLC synapses and exhibit depolarizing currents with consequent calcium transients in response to neuronal activity. SCLC cell membrane depolarization is sufficient to promote the growth of intracranial tumors. Taken together, these studies illustrate that neuronal activity plays a crucial role in dictating SCLC pathogenesis in both the lung and the brain.
2025-09-10 | GSE303152 | GEO
Project description:Prion diseases typically have long pre-clinical incubation periods during which time the infectious prion particle and infectivity steadily propagate in the brain. Abnormal neuritic sprouting and synaptic deficits are apparent during pre-clinical disease, however, gross neuronal loss is not detected until the onset of the clinical phase. The molecular events that accompany early neuronal damage and ultimately conclude with neuronal death remain obscure. In this study, we used laser capture microdissection to isolate hippocampal CA1 neurons and then determined their pre-clinical transcriptional response during infection. We found that gene expression within these neurons is dynamic and characterized by distinct phases of activity. A major cluster of genes is altered during pre-clinical disease after which expression either returns to basal levels, or alternatively undergoes a direct reversal during clinical disease. Strikingly, we show that this cluster contains a signature highly reminiscent of synaptic N-methyl-D-aspartic acid (NMDA) receptor signaling and the activation of neuroprotective pathways. Additionally, genes involved in neuronal projection and dendrite development were also altered throughout the disease, culminating in a general decline of gene expression for synaptic proteins. Similarly, deregulated miRNAs such as miR-132-3p, miR-124a-3p, miR-16-5p, miR-26a-5p, miR-29a-3p and miR-140-5p follow concomitant patterns of expression. This is the first in depth genomic study describing the pre-clinical response of hippocampal neurons to early prion replication. Our findings suggest that prion replication results in the persistent stimulation of a programmed response, at least in part mediated by synaptic NMDA receptor activity that initially promotes cell survival and neurite remodelling. However, this response is terminated prior to the onset of clinical symptoms in the infected hippocampus, seemingly pointing to a critical juncture in the disease. Manipulation of these early neuroprotective pathways may redress the balance between degeneration and survival, providing a potential inroad for treatment. The CA1 hippocampal region was dissected out using LCM and RNA was extracted from these samples. In total, 6 different time points were screened for both RNA and miRNA expression levels in prion infected and control animals. Gene expression profiles from 6 time points (n M-bM-^IM-% 2) were determined using whole mouse 4x44K arrays. We successfully validated a subset of candidate genes that were deregulated during early prion disease. We performed a similar assessment of temporal miRNAs expression levels throughout the infection using the TLDA platform which was further validated by individual real-time PCR assays. In parallel, immunoctyochemistry was used to characterize the cellular presence of astrocytes, microglial and neurons in the CA1 region throughout the disease which correlated well with both mRNA and miRNA expression profiles. Staining for the PrPRes and neuronal toxicity levels was also performed to determine the spatial and temporal PrPRes deposition and assess the level of neuronal death that occurs in the hippocampus, respectively. Using bioinformatic methods, potential pathways that were implicated by our data to be deregulated during early prion disease were presented while potential miRNA regulation of some of these candidate genes implicated in these pathways was also included.
2012-11-09 | E-GEOD-34530 | biostudies-arrayexpress
Project description:Neurons in the central nervous system (CNS) display a high capacity for axon growth during early development but mostly lose this ability during a key stage of differentiation marked by synaptic maturation, circuit integration, and a profound shift in gene transcription. Once mature, neurons largely fail to reverse this transcriptional switch after axon injury, fundamentally constraining their intrinsic capacity for repair. Here, we show with single-nucleus RNA sequencing that forced expression of the transcription factor Sox11 in adult corticospinal tract neurons produces large-scale and stable changes in gene expression that are highly enriched for growth-relevant processes, and which strongly resemble those of pre-synaptic embryonic stages. Moreover, Sox11 is equally effective when delivered to chronically injured CST neurons. These data reveal Sox11’s ability to reverse a critical step of neuronal maturation even in otherwise unperturbed neurons, clarifying the transcriptional underpinnings and highlighting Sox11’s potential as a pro-regenerative stimulus.
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