Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

NAD depletion mediates cytotoxicity in human neurons with autophagy deficiency

ABSTRACT: Metabolic profiling in wild type and autophagy-deficient human embryonic stem cell (hESC)-derived neurons after 3 weeks of neuronal differentiation. Autophagy is a homeostatic process critical for cellular survival, and its malfunction is implicated in myriad human diseases including neurodegeneration. Loss of autophagy contributes to cytotoxicity and tissue degeneration, but the mechanistic understanding of this phenomenon remains elusive. Here we have generated autophagy-deficient human embryonic stem cells (hESCs), from which we have established human neuronal platform to investigate how loss of autophagy affects neuronal survival. ATG5 deficient neurons exhibit basal cytotoxicity accompanied by metabolic defects. Depletion of nicotinamide adenine dinucleotide (NAD) due to hyperactivation of NAD-consuming enzymes is found to trigger cell death via mitochondrial depolarisation in ATG5 deficient neurons. Boosting intracellular NAD levels improve cell viability by restoring mitochondrial bioenergetics and proteostasis in ATG5 deficient neurons. Our findings elucidate a mechanistic link between autophagy deficiency and neuronal cell death that can be targeted for therapeutic interventions in neurodegenerative and lysosomal storage diseases associated with autophagic defect.

INSTRUMENT(S): Exactive

ORGANISM(S): Homo Sapiens (ncbitaxon:9606)

SUBMITTER: Sovan Sarkar

PROVIDER: MSV000091468 | MassIVE | Fri Mar 10 09:00:00 GMT 2023

REPOSITORIES: MassIVE

ACCESS DATA

Json Xml

Similar Datasets

Targeting the autophagy-NAD axis protects against cell death in Niemann-Pick type C1 disease models

Project description:Impairment of autophagy leads to an accumulation of misfolded proteins and damaged organelles and has been implicated in plethora of human diseases. Loss of autophagy in actively respiring cells has also been shown to trigger metabolic collapse mediated by the depletion of nicotinamide adenine dinucleotide (NAD) pools, resulting in cell death. Here we found that the deficit in the autophagy-NAD axis underpins the loss of viability in cell models of a neurodegenerative lysosomal storage disorder, Niemann-Pick type C1 (NPC1) disease. Defective autophagic flux in NPC1 cells resulted in mitochondrial dysfunction due to impairment of mitophagy, leading to the depletion of both the reduced and oxidised forms of NAD as identified via metabolic profiling. Consequently, exhaustion of the NAD pools triggered mitochondrial depolarisation and apoptotic cell death. Our chemical screening identified two FDA-approved drugs, celecoxib and memantine, as autophagy activators which effectively restored autophagic flux, NAD levels, and cell viability of NPC1 cells. Of biomedical relevance, either pharmacological rescue of the autophagy deficiency or NAD precursor supplementation restored NAD levels and improved the viability of NPC1 disease patient-derived primary fibroblasts and cortical neurons differentiated from induced pluripotent stem cells (iPSCs). Together, our findings identify the autophagy-NAD axis as a mechanism of cell death and a target for therapeutic interventions in NPC1 disease, with a potential relevance to other neurodegenerative disorders.

2024-04-09 | MSV000094506 | MassIVE

NAD+ supplementation normalizes key Alzheimer’s features and DNA damage in a new AD mouse model with introduced DNA repair deficiency

Project description:Emerging findings suggest that compromised cellular bioenergetics and DNA repair contribute to the pathogenesis of Alzheimer's disease (AD), but their role in disease-defining pathology is unclear. We developed a DNA repair-deficient 3xTgAD/Polb+/- mouse that exacerbates major features of human AD including pTau pathologies, synaptic dysfunction, neuronal death and cognitive impairment. Here we report that 3xTgAD/Polb+/- mice have reduced cerebral NAD+/NADH ratio indicating impaired cerebral energy metabolism, which is normalized by nicotinamide riboside (NR) treatment. NR lessened pTau pathology in both 3xTgAD and 3xTgAD/Polb+/- mice, but had no impact on Abeta accumulation. NR-treated 3xTgAD/Polb+/- mice exhibited reduced DNA damage, neuroinflammation, apoptosis of hippocampal neurons, and increased activity of SIRT3 in the brain. NR improves cognitive function in multiple behavioral tests, and restored hippocampal synaptic plasticity in 3xTgAD mice and 3xTgAD/Polb+/- mice. In general, the deficits and the benefits of NR were greater in 3xTgAD/Polb+/- mice than in 3xTgAD mice. Our findings suggest a pivotal role for cellular NAD+ depletion upstream of neuroinflammation, pTau, DNA damage, synaptic dysfunction and neuronal degeneration in AD. Interventions that bolster neuronal NAD+ levels therefore have potential in AD.

2018-02-26 | GSE109055 | GEO

Role of DNMT3B in the regulation of early neural and neural crest specifiers

Project description:The de novo DNA methyltransferase DNMT3B functions in establishing DNA methylation patterns during development. We performed RNAi knockdown of DNMT3B in human embryonic stem cells (ESCs) in order to investigate the mechanistic contribution of DNMT3B on DNA methylation and early neuronal differentiation. Genome-wide analyses of DNA methylation by MethylC-seq identified novel regions of hypomethylation in the DNMT3B knockdowns along the X chromosome as well as pericentromeric regions, rather than changes to specific dysregulated gene promoters. While DNMT3B was not required for early neuroepithelium specification, DNMT3B deficient neuroepithelium exhibited accelerated maturation with earlier expression of mature neuronal markers (such as NEUROD1) and early neuronal regional specifiers (such as neural crest) relative to normal ESCs. Our results suggest that DNMT3B mediates large-scale methylation patterns in human ESCs and that DNMT3B deficiency alters the timing of neuronal maturational differentiation in human neuronal cultures. Examined DNA methylation in human embryonic stem cells, both with and without DNMT3B knockdown

2012-03-27 | E-GEOD-32268 | biostudies-arrayexpress

Transcription profiling of mouse wild type vs Dnmt1 hypomethylated forebrain

Project description:DNA methylation is a major epigenetic factor regulating genome reprogramming, cell differentiation, developmental gene expression. To understand the role DNA methylation in CNS neurons, we generated conditional Dnmt1 mutant mice that possess ~90% hypomethylated cortical and hippocampal cells in the dorsal forebrain from E13.5 on. The mutant mice were viable with a normal lifespan, but displayed severe neuronal cell death between E14.5 to 3-weeks postnatally. Accompanied with the striking cortical and hippocampal degeneration, adult mutant mice exhibited neurobehavioral defects in learning and memory in adulthood. Unexpectedly, a fraction of Dnmt1-/- cortical neurons survived through postnatal development, so that the residual cortex in mutant mice contained 20-30% of hypomethylated neurons throughout the life. Hypomethylated excitatory neurons exhibited multiple defects in postnatal maturation including abnormal dendritic arborization and impaired neuronal excitability. The mutant phenotypes are coupled with deregulation of those genes involved in neuronal layer-specification, cell death, and the function of ion channels. Our results suggest that DNA methylation, through its role in modulating neuronal gene expression, plays multiple roles in regulating cell survival, neuronal migration and maturation in the CNS. Experiment Overall Design: We compared gene expression patterns in Wildtype and DNA methylation deficient (Emx1-cre; Dnmt1 mutant) mouse dorsal cortex. We performed 3 replicates using different each individual mouse strain. The Sample GSM350992 table is the average log ratio for the 3 replicatesArrays were performed in triplicate.

2009-12-18 | E-GEOD-14216 | biostudies-arrayexpress

Analysis of ablation of mitochondrial fission in adult forebrain neurons

Project description:Well-balanced mitochondrial fission and fusion processes are essential for nervous system development. Loss of function of the main mitochondrial fission mediator, dynamin-related protein 1 (Drp1), is lethal early during embryonic development or around birth, but the role of mitochondrial fission in adult neurons remains unclear. Here we show that inducible Drp1 ablation in neurons of the adult mouse forebrain results in progressive, neuronal subtype-specific alterations of mitochondrial morphology in the hippocampus that are marginally responsive to antioxidant treatment. Furthermore, DRP1 loss affects synaptic transmission and memory function. Although these changes culminate in hippocampal atrophy, they are not sufficient to cause neuronal cell death within 10 weeks of genetic Drp1 ablation. Collectively, our in vivo observations clarify the role of mitochondrial fission in neurons, demonstrating that Drp1 ablation in adult forebrain neurons compromises critical neuronal functions without causing overt neurodegeneration.

2016-08-25 | PXD004890 | Pride

Project description:The rise in population aging worldwide is causing an unparalleled increase in death from many cancers, including glioblastoma (GBM). Here, we have explored the impact of aging and rejuvenation on GBM tumorigenesis. Compared with old GBM, young GBM displayed elevated neuronal/synaptic signaling via brain-derived neurotrophic factor (BDNF) and SLIT and NTRK like-family member 6 (SLITRK6), promoting favorable survival rates. These effects were attributed to the rise in nicotinamide adenine dinucleotide (NAD+) levels, as brain rejuvenation by parabiosis or administration of nicotinamide mononucleotide (NMN) in mice elicited a younger phenotype with activated neuronal/synaptic signaling and improved outcomes. Our data indicate that age-associated NAD+ loss contributes to the highly aggressive GBM in the elderly. These findings have therapeutic implications in GBM and provide mechanistic insights into the exacerbation of GBM tumorigenesis with age.

2021-12-25 | GSE135210 | GEO

2021-12-25 | GSE135062 | GEO

Transcriptomic analysis of HAP1 DEGS1 KO cells and their wildtype counterpart

Project description:Genetic variants in sphingolipid metabolizing enzymes are known to cause neurodegenerative and metabolic diseases by altering the cellular sphingolipid composition. Dysfunction of delta4-dihydroceramide (dhCer) desaturase (DEGS1) has recently been associated with a rare human monogenic neurological disease affecting sphingolipid (SL) homeostasis. Patients with pathogenic DEGS1 variants show elevated levels of different dhCer species and develop a hypomyelinating leukodystrophy in early childhood. To better understand the human pathophysiology and mechanistic complexity of this severe and progressive disease, we here utilized human DEGS1-knockout (KO) HAP1 cells as a genetic KO model to comprehensively investigate the effects of elevated dihydroceramide species on various intracellular processes, like autophagy, apoptosis, ROS formation and ER Stress by using flow cytometry, Western Blot and fluorescence microscopy. DEGS1 KO cells show elevated ROS levels, enhanced autophagy and apoptosis, impaired lysosomal integrity and mild mitochondrial dysfunction. Furthermore, whole transcriptome analysis of DEGS1 KO cells by global RNA sequencing identified impaired processes associated to neuronal differentiation and synaptic function. Morphometric quantification of neuronal features in cultured primary neurons could substantiate RNA-seq results by showing a strong reduction of neuronal complexity 24 hours after Degs1-knockdown and thus impairment of neurodevelopment. In conclusion, we here demonstrate haploid DEGS1-KO cells as a valuable in vitro model for comprehensive mechanistic studies of inherited neurodegenerative diseases.

2023-01-02 | GSE213289 | GEO

Transcriptional networks identify synaptotagmin-like 3 as a regulator of cortical neuronal migration during early neurodevelopment

Project description:Human brain development is a complex process involving neural proliferation, differentiation, and migration which are directed by many essential cellular factors and drivers. Here, using the NetBID2 algorithm and developing human brain RNA sequencing(RNA-Seq) dataset, we identified synaptotagmin-like 3(SYTL3) as one of the top drivers of early human brain development. Interestingly, SYTL3 exhibited high activity but low expression in both early developmental human cortex and human embryonic stem cell(hESC)-derived neurons. Knockout of SYTL3(SYTL3 -KO) in human neurons or knockdown of Sytl3 in embryonic mouse cortex markedly promoted neuronal migration. Besides, SYTL3-KO caused an abnormal distribution of deep-layer neurons in brain organoids and reduced presynaptic neurotransmitter release in hESC-derived neurons. We further demonstrated that SYTL3-KO- accelerated neuronal migration was modulated by high expression of matrix metalloproteinases. Together, based on bioinformatics and biological experiments, we identified SYTL3 as a novel regulator of cortical neuronal migration in human and mouse developing brains.

2021-02-07 | E-MTAB-10058 | biostudies-arrayexpress

Let-7 coordinately suppresses components of the amino acid sensing pathway to induce autophagy

Project description:Macroautophagy (hereafter autophagy) is the major pathway by which macromolecules and organelles are degraded. Autophagy is regulated by the mTOR signaling pathway, which is the focal point for integration of metabolic information, with mTORC1 playing a central role in balancing biosynthesis and catabolism. Of the various inputs to mTORC1, the amino acid sensing pathway is among the most potent. Based upon transcriptome analysis of neurons subjected to nutrient deprivation, we identified let-7 as a microRNA capable of promoting neuronal autophagy. We found that let-7 activates autophagy by coordinately down-regulating the amino acid sensing pathway to prevent mTORC1 activation. Let-7 induced autophagy in the brain and greatly reduced protein aggregates in a lentivirus model of polyglutamine disease, establishing the physiological relevance of let-7 for in vivo autophagy modulation. Moreover, peripheral delivery of let-7 anti-miR repressed autophagy in muscle and white fat, suggesting that let-7 autophagy regulation extends beyond the CNS. Hence, let-7 plays a central role in nutrient homeostasis and proteostasis regulation in higher organisms. Using sets of wild-type C57BL/6J mice, we established primary cortical neuron cultures from P0 littermates, and cultured these neurons (n = 3 / set) in CM or NLM for 4 hrs.

2015-08-03 | E-GEOD-60452 | biostudies-arrayexpress

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data