Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

ADAR1 regulates dsRNA formation in nuclear and mitochondrial transcripts through editing-dependent and -independent mechanisms

ABSTRACT: Endogenous (self) double-stranded RNAs (dsRNAs) in human cells can activate innate immune responses. ADAR1, an A-to-I editing enzyme of dsRNAs, suppresses aberrant immune activation by self-dsRNAs. However, how ADAR1 influences the cellular dsRNA landscape remains unclear. We show that human ADAR1 downregulates self-dsRNA abundance through editing-dependent and editing-independent mechanisms. We further conducted quantitative dsRNA-sequencing on wild-type and ADAR1-deficient cells. dsRNAs are enriched in protein-coding mRNAs − especially those with repetitive elements and elongated 3’UTRs − and mitochondrial RNAs. ADAR1 loss markedly increased dsRNA quantity but minimally impacted dsRNA identity. ADAR1-regulated dsRNA transcripts consist of nuclear-encoded mRNAs and, unexpectedly, mitochondria-encoded RNAs rarely edited by ADAR1. Accordingly, dsRNAs accumulate to high levels within the mitochondria of ADAR1-deficient cells. Notably, ADAR1 loss sensitizes cells to inflammation under mitochondrial stress (e.g., mitochondrial herniation, X-ray radiation). Hence, we show that dsRNAs regulated by ADAR1 go beyond A-to-I edited transcripts, and that ADAR1 can control mitochondrial-dsRNAs.

ORGANISM(S): Homo sapiens

PROVIDER: GSE293278 | GEO | 2026/01/13

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other
	GSE293278_ERCC_RNA_dsRNA_seq_raw_counts.csv.gz	Csv
	GSE293278_gencode_v38_dsRNA_seq_raw_counts.csv.gz	Csv
	GSE293278_gencode_v38_total_RNA_seq_raw_counts.csv.gz	Csv

Items per page:

1 - 4 of 4

Similar Datasets

ADAR1 utilizes independent mechanisms to suppress MDA5 and PKR activation by cellular double-stranded RNA

Project description:The antiviral defense in vertebrates requires the innate immune system to sense foreign “non-self” nucleic acids while avoiding “self” nucleic acids, which is accomplished by an intricate system. Cellular double-stranded RNAs (dsRNAs) are edited by the RNA editing enzyme ADAR1 to prevent their dsRNA structure pattern from being recognized as viral dsRNA. Lack of RNA editing by ADAR1 enables activation of MDA5, a cytosolic dsRNA sensor, by cellular dsRNA. Additional RNA editing- independent functions of ADAR1 have been proposed, but the specific mechanism remains elusive. Here we demonstrate that RNA binding by ADAR1, independent of its editing activity, restricts the activation of PKR, another cytosolic dsRNA sensor, by cellular dsRNA. Mechanistically, the loss of ADAR1 editing caused MDA5 activation to induce interferon signaling, while a lack of ADAR1 protein or its dsRNA binding ability led to PKR activation, with subsequent stress granule formation and proliferation arrest. Based on these findings we rescued the Adar1−/− mice from embryonic lethality to adulthood by deleting both MDA5 and PKR, in contrast to the limited rescue of Adar1−/− mice by removing MDA5 or PKR alone. Our findings reveal a multifaceted contribution of ADAR1 in regulating the immunogenicity of “self” dsRNAs. Furthermore, ADAR1 is an immuno-oncology target for drug development, and the separation of ADAR1’s RNA editing and binding functions provides mechanistic insights for such developments.

2023-10-03 | GSE198386 | GEO

RNA 5-methylcytosine marks mitochondrial double-stranded RNAs for degradation and cytosolic release

Project description:Mitochondria are essential regulators of innate immunity. They generate long double-stranded RNAs (mt-dsRNAs) and release them to the cytosol to trigger immune response under pathological stress conditions. Yet, the regulation of these self-immunogenic RNAs remains largely unknown. Here, we employ CRISPR screening on RNA-binding proteins residing in mitochondria and identify NOP2/Sun RNA methyltransferase 4 (NSUN4) as a key regulator of mt-dsRNA expression. We find that NSUN4 induces 5-methylcytosine (m5C) modification on mitochondrial RNAs, especially on the termini of light-strand long noncoding RNAs. These m5C-modified RNAs are recognized by complement C1q binding protein (C1QBP), which recruits polyribonucleotide nucleotidyltransferase to facilitate RNA turnover. Suppression of NSUN4 or C1QBP results in increased mt-dsRNA expression while C1QBP deficiency also leads to increased cytosolic mt-dsRNAs and subsequent immune activation. Collectively, our study unveils the mechanism underlying the selective degradation of light-strand mitochondrial RNAs and establishes a molecular mark for mitochondrial RNA decay and cytosolic release.

2024-08-16 | GSE246026 | GEO

TSniffer: Unbiased de novo identification of RNA editing sites and quantification of editing activity in RNA-seq data [re-analysis]

Project description:RNA editing by adenosine deaminases acting on RNA (ADARs) is an evolutionarily conserved posttranscriptional modification essential for organismal development and normal cell function. Three catalytically active ADARs are conserved in mammals: two isoforms of ADAR1 referred to as ADAR1-p150 and ADAR1-p110, as well as ADAR2. All recognize and edit double-stranded RNA (dsRNA) structures but demonstrate target specificity and selectivity that dictate the unique essential biological functions of the three enzymes. The editing activity of ADAR1-p150 suppresses autoimmune responses against self-RNA structures, whereas ADAR1-p110 and ADAR2 have other primary functions. To better understand the mechanism of target selection by ADARs, we developed TSniffer, which allows accurate de novo identification of edited transcripts and quantification of the extent of editing within each transcript. We found that 17-40% of protein coding transcripts in mice, ferrets, and humans are edited by ADARs. Individual transcripts can harbor hundreds and thousands of editing sites, mostly within inverted retrotransposable elements. For human transcripts, we found differential editing by ADAR1 and ADAR2, aligning with a supportive role for ADAR2, while some targets were dominantly edited by ADAR1. Relying only on RNA-seq data and reference genome, TSniffer represents a novel tool to decipher the role of ADAR editing in different physiological states including disease models. Its unbiased approach is suitable for any organism.

2025-12-03 | GSE291676 | GEO

TSniffer: Unbiased de novo identification of RNA editing sites and quantification of editing activity in RNA-seq data

2025-12-03 | GSE291675 | GEO

Long 3'UTRs predispose neurons to inflammation by promoting immunostimulatory double-stranded RNA formation

Project description:Loss of RNA homeostasis underlies numerous neurodegenerative and neuroinflammatory diseases. However, the molecular mechanisms that trigger neuroinflammation are poorly understood. Viral double-stranded RNA (dsRNA) triggers innate immune responses when sensed by host pattern recognition receptors (PRRs) present in all cell types. Here, we report that human neurons intrinsically carry exceptionally high levels of immunostimulatory dsRNAs and identify long 3'UTRs as giving rise to neuronal dsRNA structures. We found that the neuron-enriched ELAVL family of genes (ELAVL2, -3, -4) can increase 1) 3'UTR length, 2) dsRNA load, and 3) activation of dsRNA-sensing PRRs such as MDA5, PKR, and TLR3. In wild-type neurons, neuronal dsRNAs signaled through PRRs to induce tonic production of the antiviral type I interferon. Depleting ELAVL2 in WT neurons led to global shortening of 3'UTR length, reduced immunostimulatory dsRNA levels, and rendered WT neurons susceptible to herpes simplex virus and Zika virus infection. Neurons deficient in ADAR1, a dsRNA-editing enzyme mutated in the neuroinflammatory disorder Aicardi-Goutières syndrome, exhibited intolerably high levels of dsRNA that triggered PRR mediated toxic inflammation and neuronal death. Depleting ELAVL2 in ADAR1 knockout neurons led to prolonged neuron survival by reducing immunostimulatory dsRNA levels. In summary, neurons are specialized cells where PRRs constantly sense ‘self’ dsRNAs to pre-emptively induce protective antiviral immunity, but maintaining RNA homeostasis is paramount to prevent pathological neuroinflammation.

2023-10-20 | GSE214949 | GEO

Inhibiting DDX3X triggers tumor-intrinsic type I interferon response and enhances anti-tumor immunity

Project description:Accumulating evidence has shown that cellular double-stranded RNAs (dsRNAs) induce antiviral innate immune responses in human normal and malignant cancer cells. However, it is not fully understood how endogenous ‘self’ dsRNA homeostasis is regulated in the cell. Here, we show that an RNA-binding protein, DEAD-box RNA helicase 3X (DDX3X), prevents the aberrant accumulation of cellular dsRNAs. Loss of DDX3X induces dsRNA sensor-mediated type I interferon signaling and innate immune response in breast cancer cells due to abnormal cytoplasmic accumulation of dsRNAs. Dual depletion of DDX3X and a dsRNA-editing protein, ADAR1 synergistically activates the cytosolic dsRNA pathway in breast cancer cell. Moreover, inhibiting DDX3X enhances the antitumor activity by increasing tumor intrinsic-type I interferon response, antigen presentation, and tumor-infiltration of cytotoxic T cells as well as dendritic cells in breast tumors, which may lead to the development of breast cancer therapy by targeting DDX3X in combination with immune checkpoint blockade. To assess the impact of DDX3X on the gene expression in the breast cancer, we stably depleted DDX3X in breast cancer MCF7 cells using a short hairpin RNA (shRNA)-mediated knockdown, and performed a genome-wide transcriptome analysis using a next-generation RNA deep sequencing.

2020-09-03 | GSE157323 | GEO

Malignant A-to-I RNA editing by ADAR1 drives T-cell acute lymphoblastic leukemia relapse via attenuating dsRNA sensing

Project description:Leukemia initiating cells (LICs) are regarded as the origin of leukemia relapse and therapeutic resistance. Identifying direct stemness determinants that fuel LIC self-renewal is critical for developing targeted approaches to eliminate LICs and prevent relapse. Here, we show that the RNA editing enzyme ADAR1 is a crucial stemness factor that promotes LIC self-renewal by attenuating aberrant double-stranded RNA (dsRNA) sensing. Elevated adenosine-to-inosine (A-to-I) editing is a common attribute of relapsed T-ALL regardless of molecular subtypes. Consequently, knockdown of ADAR1 severely inhibits LIC self-renewal capacity and prolongs survival in T-ALL PDX models. Mechanistically, ADAR1 directs hyper-editing of immunogenic dsRNA to avoid detection by the innate immune sensor MDA5. Moreover, we uncovered that the cell intrinsic level of MDA5 dictates the dependency on ADAR1-MDA5 axis in T-ALL. Collectively, our results show that ADAR1 functions as a self-renewal factor that limits the sensing of endogenous dsRNA. Thus, targeting ADAR1 presents an effective therapeutic strategy for eliminating T-ALL LICs.

2023-12-31 | GSE221112 | GEO

RNA-seq analysis of YUMM1.7 mouse melanoma cells treated with ADAR1i-124 or 5-AZA-CdR to study their effects on RNA editing

Project description:ADAR1i-124 is a small-molecule RNA editing inhibitor that can block the editase domain of ADAR1 and robustly suppress the A-to-I RNA editing on double-stranded RNAs (dsRNAs). 5-AZA-CdR is an FDA-approved DNA methyltransferase inhibitor (DNMTi) that can increase the transcription of transposable elements and thus induce more dsRNAs. To determine the efficacy of ADAR1i-124 and test whether it has overlapping targets or synergistic effects with 5-AZA-CdR, total RNA-seq analysis was performed on YUMM1.7 cells treated with 5-AZA-CdR (1 uM, 72 h), ADAR1i-124 (10 uM, 12 h) or combination of two treatments , using 0.1% DMSO as control. Immunoprecipitation (IP) with the J2 or Z22 antibodies was also adopted to enrich the dsRNA species and investigate how drugs affect the dsRNA forms and IP enrichment.

2025-11-13 | GSE284082 | GEO

The RNA editing enzyme ADAR1 is a key regulatory of innate immune responses to RNA

Project description:The ADAR RNA editing enzymes deaminate adenosine bases to inosines in cellular RNAs, recoding open reading frames. Human ADAR1 mutations cause Aicardi-Goutieres Syndrome (AGS) and Adar1 mutant mice showing an aberrant interferon response and death by embryonic day E12.5 model the human disease. Searches have not identified key ADAR1 RNA editing sites recoding immune/haematopoietic proteins but editing is widespread in Alu sequences. We show that Adar1 embryonic lethality is rescued in Adar1; Mavs double mutant mice in which general antiviral responses to cytoplasmic dsRNA are prevented. We propose that inosine bases are epigenetic marks identifying cellular RNA as innate immune ÒselfÓ. Consistent with this idea we show that an editing-active cytoplasmic ADAR is required to prevent aberrant immune responses in Adar1 mutant mouse embryo fibroblasts. No dramatic increase in repetitive transcripts is observed. AGS mutations in ADAR1 affect editing by the interferon-inducible cytoplasmic ADAR1 isoform. RNA-seq expression profiling in Adar1 and Adar1/Mavs knockout mice embryos.

2014-12-19 | E-GEOD-62917 | biostudies-arrayexpress

ADAR1 masks the cancer immunotherapeutic promise of ZBP1-driven necroptosis

Project description:A disappointingly small proportion (10-30%) of patients with cancer show lasting responses to immune checkpoint blockade (ICB)-based monotherapies. The RNA-editing enzyme ADAR1 is an emerging determinant of resistance to ICB therapy, and prevents ICB responsiveness by repressing immunogenic double-stranded (ds)RNAs, such as those arising from the dysregulated expression of endogenous retroelements (EREs). These dsRNAs trigger an interferon (IFN)-dependent antitumor response by activating the A-form dsRNA (A-RNA) sensing proteins MDA-5, PKR, and OAS1. Here, we show that ADAR1 also prevents accrual of endogenous Z-form dsRNA elements (Z-RNAs) which were enriched in the 3’UTRs of IFN-stimulated mRNAs. Depleting ADAR1 resulted in Z-RNA accumulation and activation of the Z-RNA sensor ZBP1, culminating in RIPK3-mediated necroptosis. As no clinically viable ADAR1 inhibitors currently exist, we searched for a compound that can override the requirement for ADAR1 inhibition and directly activate ZBP1. We identified a small molecule, the curaxin CBL0137, which potently activates ZBP1 by triggering Z-DNA formation in cells. CBL0137 induced ZBP1-dependent necroptosis in cancer-associated fibroblasts and strongly reversed ICB unresponsiveness in mouse models of melanoma. Collectively, these results demonstrate that ADAR1 represses endogenous Z-RNAs and identifies ZBP1-mediated necroptosis as a new determinant of tumor immunogenicity masked by ADAR1. Therapeutic activation of ZBP1-induced necroptosis provides a readily-translatable avenue for rekindling immune responsiveness of ICB-resistant human cancers.

2022-03-03 | GSE184960 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

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