Rare ADAR1 loss-of-function variants alter RNA editing and drive interferon-dependent inflammation in psoriasis
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE301804 | GEO | 2026/04/20
REPOSITORIES: GEO
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Project description:In 4 unrelated pedigrees, we report rare heterozygous loss-of-function ADAR1 mutations cosegregating with autosomal dominant, early onset psoriasis and increased type I interferon (IFN)-stimulated gene (ISG) transcripts in skin lesions and/or blood. We identified 6 additional variants in a psoriasis cohort. Skin single cell transcriptomics identified keratinocytes and melanocytes as key IFN sources. ADAR1 knockdown in keratinocytes and melanocytes, and transduction of ADAR1G1119R and ADAR1P3A alleles in keratinocytes, led to reduced A-to-I RNA editing and upregulation of ISG expression, reversed by JAK1 and TYK2 inhibition, mirroring their clinical benefit in these patients. This set of data defines a new IFN-dependent psoriasis subtype resulting from inborn errors of ADAR1-dependent RNA editing, leading to IFN constitutive dysregulation, and opens new avenues in precision medicine.
2026-04-27 | PXD065122 | Pride
Project description:The interleukin (IL)-23/T-helper type 17 cell axis is a target for psoriasis. The tyrosine kinase 2 (TYK2)/Janus kinase 1 (JAK1) inhibitor, PF 06700841, will directly suppress TYK2-dependent IL-12 and IL-23 signaling and JAK1-dependent signaling in cells expressing these signaling molecules, including T cells and keratinocytes. This clinical study sought to define the inflammatory gene and cellular pathways through which PF 06700841 improves the clinical manifestations of psoriasis. Patients (n=30) with moderate-to-severe psoriasis were randomized to once-daily 30 mg (n=14) or 100 mg (n=7) PF 06700841, or placebo (n=9) for 28 days. Biopsies were taken from non-lesional and lesional skin at baseline, weeks 2 and 4. Changes in the psoriasis transcriptome and genes induced by IL-17 in keratinocytes were evaluated with microarray profiling and RT-PCR. Reductions in IL-17A, IL-17F, and IL-12B mRNA were observed as early as 2 weeks and ~70% normalization of lesional gene expression after 4 weeks. Immunohistochemistry showed significant decreases in markers of keratinocyte activation, epidermal thickness, KRT16 and Ki-67 expression, and immune cell infiltrates CD3+/CD8+ (T cells) and CD11c (dendritic cells) after 2 weeks of treatment, corresponding with improvement in histologic score. PF 06700841 improves clinical symptoms of chronic plaque psoriasis by inhibition of pro-inflammatory cytokines that require TYK2 and JAK1 for signal transduction.
2020-03-03 | GSE136757 | GEO
Project description:Single-cell RNA sequencing is transforming how we understand skin immunology, but previous human skin single-cell RNA sequencing data included only a small fraction of inflammatory cells among the overall cell population, such that functional subsets may be difficult to ascertain. We have overcome these obstacles by harvesting inflammatory cells emigrating from a half of 6 mm punch biopsy skin after 48-hour incubation in culture medium without any enzyme, and then analyzing the harvested cells with single-cell RNA sequencing. By this strategy, we obtained single-cell RNA sequencing data of 24,354 cells (leukocytes 46.0%, keratinocytes 49.6%, and melanocytes 2.4%) from 13 human psoriasis skin and 5 healthy volunteer skin. Unsupervised clustering identified NK cells, CD161+ T-cells, CD8+ T-cells, CD4+ T-cells, regulatory T-cells, mature & semimature dendritic cells, melanocytes, and keratinocytes in different layers - S. (Stratum) corneum, S. granulosum, S. spinosum, and S. basale. To understand psoriasis immunopathogenesis at single-cell levels, we compared gene expression between psoriasis cells vs. control cells within each inflammatory cell subtype clusters.
2021-05-03 | GSE151177 | GEO
Project description:Diffuse large B cell lymphoma (DLBCL) is one of the most common and aggressive types of B cell lymphoma. Subtype heterogeneity cannot be completely explained by genomic alterations and/or gene expression differences, suggesting that additional mechanisms are involved. Here, we explore the contribution of an epitranscriptomic modification to B cell lymphomagenesis. Our data demonstrate that ADAR1-mediated RNA editing (deamination of adenosine to inosine) targets novel candidate driver genes within well-known disease-associated pathways in DLBCL. Within these pathways, DNA mutations and RNA editing events are often mutually exclusive at the gene level, suggesting that tumours can modulate pathway outcomes by altering sequence at either the genomic or the transcriptomic level. In contrast to what has been found in solid tumours, in DLBCL low ADAR1 expression correlates with low interferon-stimulated gene (ISG) scores and with a microenvironment that is not inflamed. To investigate the molecular mechanism behind the inability of DLBCL to mount an ISG response upon loss of ADAR1, we focused on one candidate MAVS, a central regulator of ISG (as well as NFkB) signaling. MAVS is never mutated but robustly edited by ADAR1 at its 3’UTR, and editing correlates with increased MAVS protein levels and increased downstream activation of the ISG as well as NFkB pathways. Using targeted base editing tools to specifically restore MAVS editing in ADAR1-deficient cells, we demonstrate that MAVS editing is directly causal to an increase in expression of genes downstream this signaling pathway. Our data imply that DLBCL tumours edit MAVS to strengthen NFkB signaling, to which they are dependent on survival; thus, targeted loss of MAVS editing might sensitize tumours to cell death. Overall, ADAR1-mediated RNA editing represents a new tumour evasion mechanism underlying DLBCL lymphomagenesis, with features distinct from those derived from solid tumours to date.
2022-09-01 | GSE145011 | GEO
Project description:Ultraviolet (UV) radiation is a major melanoma risk factor, yet underlying mechanisms remain poorly understood. Here we introduce a mouse model permitting fluorescence-aided melanocyte imaging and isolation following in vivo UV irradiation. We use expression profiling to show that activated neonatal skin melanocytes isolated following a melanomagenic UVB dose bear a distinct, persistent interferon-response signature, including genes associated with immunoevasion. UVB-induced melanocyte activation, characterized by aberrant growth and migration, was abolished by antibody-mediated systemic blockade of interferon-gamma (IFN-gamma), but not type-I interferons. IFN-gamma was produced by macrophages recruited to neonatal skin by UVB-induced chemokine receptor Ccr2 ligands. Admixed recruited skin macrophages enhanced transplanted melanoma growth by inhibiting apoptosis; notably, IFN-gamma blockade abolished macrophage-associated melanoma growth and survival. IFN-gamma-producing macrophages were identified in 70% of human melanomas examined. Our data reveal an unanticipated role for IFN-gamma in promoting melanocytic cell survival/immunoevasion, and suggest IFN-gamma-R signaling represents a novel therapeutic melanoma target. Biologic replicates of UVA- and UVB-treated mouse melanocytes, as well as untreated mouse melanocytes and mouse keratinocytes, were used to define melanocyte expression signatures associated with UV treatment.
2011-01-01 | E-GEOD-25164 | biostudies-arrayexpress
Project description:The RNA editing enzyme ADAR1, is essential for correct functioning of innate immune responses. The ADAR1p110 isoform is mainly nuclear and ADAR1p150, which is interferon inducible, is predominately cytoplasmic. Using three different approaches, co-IP with endogenous ADAR1, and Strep-tag co-IP and BioID with individual ADAR1 isoforms, a comprehensive interactome was generated during both homeostasis and the IFN response. Both known and novel interactors and editing regulators were identified. Nuclear proteins were detected as stable interactors with both ADAR1 isoforms. In contrast, BioID identified distinct protein networks for each ADAR1 isoform, with nuclear components observed with ADAR1p110 and components of cytoplasmic cellular condensates with ADAR1p150. RNase A digestion distinguished between distal and proximal interactors, as did a dsRNA-binding mutant of ADAR1 which demonstrated the importance of dsRNA binding for ADAR1 interactions. IFN treatment did not affect the core ADAR1 interactomes but resulted in novel interactions, the majority of which are proximal interactions retained after RNase A treatment. Short treatment with HMW poly(I:C) during the IFN response resulted in dsRNA-binding-dependent changes in the proximal protein network of ADAR1p110 and association of the ADAR1p150 proximal protein network with some components of antiviral stress granules.
2024-12-08 | PXD056080 | Pride
Project description:Adenosine deaminases acting on RNA (Adar1 and Adar2) catalyze I-to-A RNA editing, a post-transcriptional mechanism involved in multiple cellular functions. The role of Adar1-dependent RNA editing in cardiomyocytes (CMs) remains unclear. Here we show that conditional deletion of Adar1 in CMs results in myocarditis progressively evolving into dilated cardiomyopathy and heart failure at only 6 months of age. Adar1 depletion drives activation of interferon signaling genes (ISGs) in the absence of apoptosis and cytokine activation, and reduces the hypertrophic response of CMs upon pressure overload. Interestingly, ablation of the cytosolic sensor MDA5 prevents cardiac ISG activation and delays disease onset, but does not rescue the long-term lethal phenotype elicited by conditional deletion of Adar1. Retention of a single catalytically inactive Adar1 allele in CMs, in combination with MDA5 depletion, however, completely restores the cardiac function and prevents heart failure. Finally, ablation of interferon regulatory factor 7 (Irf7) attenuates the phenotype of Adar1-deficient CMs to a similar extent as MDA5 depletion, highlighting Irf7 as the main regulator of the immune response triggered by lack of Adar1 in CMs.
2022-08-24 | PXD024974 | Pride
Project description:ADAR1 is an interferon (IFN) inducible RNA editing enzyme that converts adenosine (A) to inosine (I). Here we identified ADAR1 and ADAR1p150 specific editing events by conducting RNA-seq on WT, ADAR1 KO, and ADAR1p150 KO cells.
2018-02-09 | GSE99249 | GEO
Project description:Psoriasis is a chronic, debilitating, immune-mediated inflammatory skin disease. As IFN-gamma is involved in many cellular processes, including activation of T cells and dendritic cells (DCs), antigen processing and presentation, cell adhesion and trafficking, and cytokine and chemokine production, IFN-gamma-producing Th1 cells were proposed to be integral to the pathogenesis of psoriasis. Recently, IFN-gamma was shown to enhance IL-23 and IL-1 production by DCs and subsequently induce Th17 cells, important contributors to the inflammatory cascade in psoriasis lesions. To determine if IFN-gamma indeed induces the pathways leading to the development of psoriasis lesions, a single intradermal injection of IFN-gamma was administered to an area of clinically normal, non-lesional skin of psoriasis patients and biopsies were collected 24 hours later. Although there were no visible changes in the skin, IFN-gamma induced molecular and histological features characteristic of psoriasis lesions. IFN-gamma increased a number of differentially expressed genes in the skin, including many chemokines concomitant with an influx of T cells and inflammatory DCs. Furthermore, inflammatory DC products TNF, iNOS, IL-23, and TRAIL were present in IFN-gamma-treated skin. Thus, IFN-gamma, which is significantly elevated in non-lesional skin compared to healthy skin, appears to be a key pathogenic cytokine that can induce the inflammatory cascade in psoriasis. RNA was isolated from whole skin punch biopsies of either healthy or non-lesional psoraisis patients at baseline or 24 hours after placebo or IFN-g injection.
2011-11-30 | E-GEOD-32407 | biostudies-arrayexpress
Project description:The A-to-I RNA editing enzyme ADAR1 critically regulates the cellular RNA sensing signaling pathway, as the RNA-sensing signaling pathway recognizes unedited RNAs as “non-self” to activate the innate immune response. Mutations of ADAR1 cause severe inflammatory tissue injury, as shown in Aicardi-Goutières syndrome (AGS), in which severe inflammation occurs in the brain. The most frequent ADAR1 mutation in AGS is the P193A mutation in the Za domain, which exists in the AGS families coupling with an additional ADAR1 mutation. How this mutation alters the cellular RNAs leading to innate immune activation, has not been fully understood. This study analyzed RNA editing status and innate immune activation in the brains of a mouse model that carries the human ADAR1 P193A-equivalent mouse P195A mutation. We found that this mutation alone can cause excessive ISG expression in the brains, especially in the periventricular areas reflecting the pathologic feature of AGS. Furthermore, we found that ADAR1 P195A mutation did not affect the RNA editing activity in the overall RNA editing level; however, it leads to ISG expression in a dose-dependent manner, causing severer innate immune activation in haploinsufficiency status, whereas wildtype ADAR1 is redundant to suppress innate immune activation. The finding from this study indicated that the intact Z-RNA binding activity of ADAR1 plays a critical role in suppressing self-cellular RNA sensing, and innate immune homeostasis requires a minimum Z-RNA binding capacity of ADAR1.
2023-05-31 | GSE229884 | GEO