ABSTRACT
Nuclear factor kappa B (NFκB) is a pathogenic factor in chronic lymphocytic leukemia (CLL) that is not addressed specifically by current therapies. NFκB is activated by inflammatory factors that stimulate toll-like receptors (TLRs) and receptors for interleukin-1 (IL-1) family members. IL-1 is considered a master regulator of inflammation, and IL-1 receptor signaling is inhibited by the IL-1 receptor antagonist anakinra. These considerations suggested that anakinra might have a role in the treatment of CLL. Consistent with this idea, anakinra inhibited spontaneous and TLR7-mediated activation of the canonical NFκB pathway in CLL cells in vitro. However, CLL cells exhibited only weak signaling responses to IL-1 itself, and anakinra was found to inhibit NFκB along with oxidative stress in an IL-1 receptor-independent manner. Anakinra was then administered with minimal toxicity to 11 previously untreated CLL patients in a phase I dose-escalation trial (NCT04691765). A stereotyped clinical response was observed in all patients. Anakinra lowered blood lymphocytes and lymph node sizes within the first month that were associated with downregulation of NFκB and oxidative stress in the leukemia cells. However, inhibition of NFκB was accompanied by upregulation of type 1 interferon (IFN) signaling, c-MYC-regulated genes and proteins, and loss of the initial clinical response. Anakinra increased IFN signaling and survival of CLL cells in vitro that were, respectively, phenocopied by mitochondrial antioxidants and reversed by IFN receptor blocking antibodies. These observations suggest that anakinra has activity in CLL and may be a useful adjunct for conventional therapies as long as compensatory IFN signaling is blocked at the same time.
Subject(s)
Interleukin 1 Receptor Antagonist Protein , Leukemia, Lymphocytic, Chronic, B-Cell , NF-kappa B , Signal Transduction , Aged , Female , Humans , Male , Middle Aged , Interferons/metabolism , Interleukin 1 Receptor Antagonist Protein/pharmacology , Interleukin 1 Receptor Antagonist Protein/therapeutic use , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Leukemia, Lymphocytic, Chronic, B-Cell/metabolism , NF-kappa B/metabolism , Oxidative Stress/drug effects , Receptors, Interleukin-1/metabolism , Receptors, Interleukin-1/antagonists & inhibitors , Signal Transduction/drug effects , Toll-Like Receptor 7/metabolism , Toll-Like Receptor 7/antagonists & inhibitorsABSTRACT
Enteric glia have been recently recognized as key components of the colonic tumor microenvironment indicating their potential role in colorectal cancer pathogenesis. Although enteric glia modulate immune responses in other intestinal diseases, their interaction with the colorectal cancer immune cell compartment remains unclear. Through a combination of single-cell and bulk RNA-sequencing, both in murine models and patients, here we find that enteric glia acquire an immunomodulatory phenotype by bi-directional communication with tumor-infiltrating monocytes. The latter direct a reactive enteric glial cell phenotypic and functional switch via glial IL-1R signaling. In turn, tumor glia promote monocyte differentiation towards pro-tumorigenic SPP1+ tumor-associated macrophages by IL-6 release. Enteric glia cell abundancy correlates with worse disease outcomes in preclinical models and colorectal cancer patients. Thereby, our study reveals a neuroimmune interaction between enteric glia and tumor-associated macrophages in the colorectal tumor microenvironment, providing insights into colorectal cancer pathogenesis.
Subject(s)
Colorectal Neoplasms , Neuroglia , Signal Transduction , Tumor Microenvironment , Animals , Colorectal Neoplasms/pathology , Colorectal Neoplasms/immunology , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/genetics , Humans , Tumor Microenvironment/immunology , Neuroglia/metabolism , Mice , Macrophages/metabolism , Macrophages/immunology , Receptors, Interleukin-1/metabolism , Receptors, Interleukin-1/genetics , Tumor-Associated Macrophages/immunology , Tumor-Associated Macrophages/metabolism , Interleukin-6/metabolism , Monocytes/metabolism , Monocytes/immunology , Mice, Inbred C57BL , Cell Communication , Cell Differentiation , Cell Line, Tumor , FemaleABSTRACT
After recognizing its ligand lipopolysaccharide, Toll-like receptor 4 (TLR4) recruits adaptor proteins to the cell membrane, thereby initiating downstream signaling and triggering inflammation. Whether this recruitment of adaptor proteins is dependent solely on protein-protein interactions is unknown. Here, we report that the sphingolipid sphinganine physically interacts with the adaptor proteins MyD88 and TIRAP and promotes MyD88 recruitment in macrophages. Myeloid cell-specific deficiency in serine palmitoyltransferase long chain base subunit 2, which encodes the key enzyme catalyzing sphingolipid biosynthesis, decreases the membrane recruitment of MyD88 and inhibits inflammatory responses in in vitro bone marrow-derived macrophage and in vivo sepsis models. In a melanoma mouse model, serine palmitoyltransferase long chain base subunit 2 deficiency decreases anti-tumor myeloid cell responses and increases tumor growth. Therefore, sphinganine biosynthesis is required for the initiation of TLR4 signal transduction and serves as a checkpoint for macrophage pattern recognition in sepsis and melanoma mouse models.
Subject(s)
Macrophages , Melanoma , Myeloid Differentiation Factor 88 , Sepsis , Serine C-Palmitoyltransferase , Sphingosine , Toll-Like Receptor 4 , Animals , Toll-Like Receptor 4/metabolism , Sepsis/metabolism , Macrophages/metabolism , Myeloid Differentiation Factor 88/metabolism , Mice , Sphingosine/analogs & derivatives , Sphingosine/metabolism , Melanoma/metabolism , Melanoma/pathology , Melanoma/genetics , Serine C-Palmitoyltransferase/metabolism , Serine C-Palmitoyltransferase/genetics , Humans , Signal Transduction , Disease Models, Animal , Inflammation/metabolism , Receptors, Interleukin-1/metabolism , Receptors, Interleukin-1/genetics , Membrane Glycoproteins/metabolism , Membrane Glycoproteins/genetics , Mice, Inbred C57BL , Mice, Knockout , HEK293 Cells , LipopolysaccharidesABSTRACT
Introduction: Antibody production and the generation of memory B cells are regulated by T follicular helper (Tfh) and T follicular regulatory (Tfr) cells in germinal centers. However, the precise role of Tfr cells in controlling antibody production is still unclear. We have previously shown that both Tfh and Tfr cells express the IL-1R1 agonist receptor, whereas only Tfr cells express the IL-1R2 decoy and IL-1Ra antagonist receptors. We aimed to investigate the role of IL-1 receptors in the regulation of B cell responses by Tfh and Tfr. Methods: We generated mice with IL-1 receptors inactivated in Tfh or Tfr and measured antibody production and cell activation after immunisation. Results: While IL-1ß levels are increased in the draining lymph node after immunisation, antigen-specific antibody levels and cell phenotypes indicated that IL-1ß can activate both Tfh and Tfr cells through IL-1R1 stimulation. Surprisingly, expression of IL-1R2 and IL-1Ra on Tfr cells does not block IL-1 activation of Tfh cells, but rather prevents IL-1/IL-1R1-mediated early activation of Tfr cells. IL-1Rs also regulate the antibody response to autoantigens and its associated pathophysiology in an experimental lupus model. Discussion: Collectively, our results show that IL-1 inhibitory receptors expressed by Tfr cells prevent their own activation and suppressive function, thus licensing IL-1-mediated activation of Tfh cells after immunisation. Further mechanistic studies should unravel these complex interactions between IL-1ß and follicular helper and regulatory T cells and provide new avenues for therapeutic intervention.
Subject(s)
Germinal Center , T Follicular Helper Cells , T-Lymphocytes, Regulatory , Animals , Germinal Center/immunology , Mice , T Follicular Helper Cells/immunology , T-Lymphocytes, Regulatory/immunology , Lymphocyte Activation/immunology , Receptors, Interleukin-1 Type I/genetics , Receptors, Interleukin-1 Type I/immunology , Mice, Inbred C57BL , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , Interleukin-1beta/metabolism , Interleukin-1beta/immunology , Interleukin-1/metabolism , Interleukin-1/immunology , Receptors, Interleukin-1/metabolism , Receptors, Interleukin-1/immunology , Antibody Formation/immunologyABSTRACT
BACKGROUND: Clinical trials of renal denervation for the treatment of hypertension have shown a variety of off-target improvements in conditions associated with sympathetic overactivity. This may be due to the ablation of sympathoexcitatory afferent renal nerves, which are overactive under conditions of renal inflammation. Renal IL (interleukin)-1ß is elevated in the deoxycorticosterone acetate-salt model of hypertension, and its activity may be responsible for the elevation in afferent renal nerve activity and arterial pressure. METHODS: Continuous blood pressure recording of deoxycorticosterone acetate-salt mice with IL-1R (IL-1 receptor) knockout or antagonism was used individually and combined with afferent renal denervation (ARDN) to assess mechanistic overlap. Protein quantification and histological analysis of kidneys were performed to characterize renal inflammation. RESULTS: ARDN attenuated deoxycorticosterone acetate-salt hypertension (-20±2-Δmmâ Hg mean arterial pressure [MAP] relative to control at study end) to a similar degree as total renal denervation (-21±2-Δmmâ Hg MAP), IL-1R knockout (-16±4-Δmmâ Hg MAP), or IL-1R antagonism (-20±3-Δmmâ Hg MAP). The combination of ARDN with knockout (-18±2-Δmmâ Hg MAP) or antagonism (-19±4-Δmmâ Hg MAP) did not attenuate hypertension any further than ARDN alone. IL-1R antagonism was found to have an acute depressor effect (-15±3-Δmmâ Hg MAP, day 10) in animals with intact renal nerves but not those with ARDN. CONCLUSIONS: These findings suggest that IL-1R signaling is partially responsible for the elevated afferent renal nerve activity, which stimulates central sympathetic outflow to drive deoxycorticosterone acetate-salt hypertension.
Subject(s)
Blood Pressure , Desoxycorticosterone Acetate , Disease Models, Animal , Hypertension , Kidney , Mice, Knockout , Animals , Mice , Kidney/innervation , Kidney/metabolism , Hypertension/chemically induced , Hypertension/physiopathology , Hypertension/metabolism , Blood Pressure/physiology , Receptors, Interleukin-1/metabolism , Receptors, Interleukin-1/genetics , Male , Sympathetic Nervous System/physiopathology , Sensory Receptor Cells/metabolismABSTRACT
Hyperinflammatory responses are pivotal in the cardiomyocyte senescence pathophysiology, with IL33 serving as a crucial pro-inflammatory mediator. Our previous findings highlighted RND3's suppressive effect on IL33 expression. This study aims to explore the role of RND3 in IL33/ST2 signaling activation and in cardiomyocyte senescence. Intramyocardial injection of exogenous IL33 reduces the ejection fraction and fractional shortening of rats, inducing the appearance of senescence-associated secretory phenotype (SASP) in myocardial tissues. Recombinant IL33 treatment of AC16 cardiomyocytes significantly upregulated expression of SASP factors like IL1α, IL6, and MCP1, and increased the p-p65/p65 ratio and proportions of SA-ß-gal and γH2AX-positive cells. NF-κB inhibitor pyrrolidinedithiocarbamate ammonium (PDTC) and ST2 antibody astegolimab treatments mitigated above effects. RND3 gene knockout H9C2 cardiomyocytes using CRISPR/Cas9 technology upregulated IL33, ST2L, IL1α, IL6, and MCP1 levels, decreased sST2 levels, and increased SA-ß-gal and γH2AX-positive cells. A highly possibility of binding between RND3 and IL33 proteins was showed by molecular docking and co-immunoprecipitation, and loss of RND3 attenuated ubiquitination mediated degradation of IL33; what's more, a panel of ubiquitination regulatory genes closely related to RND3 were screened using qPCR array. In contrast, RND3 overexpression in rats by injection of AAV9-CMV-RND3 particles inhibited IL33, ST2L, IL1α, IL6, and MCP1 expression in cardiac tissues, decreased serum IL33 levels, and increased sST2 levels. These results suggest that RND3 expression in cardiomyocytes modulates cell senescence by inhibiting the IL33/ST2/NF-κB signaling pathway, underscoring its potential as a therapeutic target in cardiovascular senescence.
Subject(s)
Cellular Senescence , Interleukin-33 , Myocytes, Cardiac , Signal Transduction , Animals , Male , Rats , Cell Line , Cellular Senescence/drug effects , Interleukin-33/metabolism , Myocytes, Cardiac/metabolism , NF-kappa B/metabolism , Rats, Sprague-Dawley , Receptors, Interleukin-1 , rho GTP-Binding Proteins/metabolism , rho GTP-Binding Proteins/geneticsABSTRACT
IL-36 cytokines are emerging as beneficial in immunity against pathogens and cancers but can also be detrimental when dysregulated in autoimmune and autoinflammatory conditions. Interest in targeting IL-36 activity for therapeutic purposes is rapidly growing, yet many unknowns about the functions of these cytokines remain. Thus, the availability of robust research tools is essential for both fundamental basic science and pre-clinical studies to fully access outcomes of any manipulation of the system. For this purpose, a floxed Il1rl2, the gene encoding the IL-36 receptor, mouse strain was developed to facilitate the generation of conditional knockout mice. The targeted locus was engineered to contain an inverted mCherry reporter sequence that upon Cre-mediated recombination will be flipped and expressed under the control of the endogenous Il1rl2 promoter. This feature can be used to confirm knockout in individual cells but also as a reporter to determine which cells express the IL-36 receptor IL-1RL2. The locus was confirmed to function as intended and further used to demonstrate the expression of IL-1RL2 in barrier tissues. Il1rl2 expression was detected in leukocytes in all barrier tissues. Interestingly, strong expression was observed in epithelial cells at locations in direct contact with the environment such as the skin, oral mucosa, the esophagus, and the upper airways, but almost absent from epithelial cells at more inward facing sites, including lung alveoli, the small intestine, and the colon. These findings suggest specialized functions of IL-1RL2 in outward facing epithelial tissues and cells. The generated mouse model should prove valuable in defining such functions and may also facilitate basic and translational research.
Subject(s)
Receptors, Interleukin-1 , Animals , Mice , Gene Expression Regulation , Genes, Reporter , Genetic Loci , Interleukin-1 Receptor-Like 1 Protein/metabolism , Interleukin-1 Receptor-Like 1 Protein/genetics , Mice, Inbred C57BL , Mice, Knockout , Receptors, Interleukin-1/metabolism , Receptors, Interleukin-1/genetics , Red Fluorescent Protein/geneticsABSTRACT
Hyperinflammatory disease is associated with an aberrant immune response resulting in cytokine storm. One such instance of hyperinflammatory disease is known as macrophage activation syndrome (MAS). The pathology of MAS can be characterised by significantly elevated serum levels of interleukin-18 (IL-18) and interferon gamma (IFNγ). Given the role for IL-18 in MAS, we sought to establish the role of inflammasomes in the disease process. Using a murine model of CpG-oligonucleotide-induced MAS, we discovered that the expression of the NLRP3 inflammasome was increased and correlated with IL-18 production. Inhibition of the NLRP3 inflammasome or the downstream caspase-1 prevented MAS-mediated upregulation of IL-18 in the plasma but, interestingly, did not alleviate key features of hyperinflammatory disease including hyperferritinaemia and splenomegaly. Furthermore blockade of IL-1 receptor with its antagonist IL-1Ra did not prevent the development of CpG-induced MAS, despite being clinically effective in the treatment of MAS. These data demonstrate that, during the development of MAS, the NLRP3 inflammasome was essential for the elevation in plasma IL-18 - a key cytokine in clinical cases of MAS - but was not a driving factor in the pathogenesis of CpG-induced MAS.
Subject(s)
Disease Models, Animal , Inflammasomes , Interleukin-18 , Macrophage Activation Syndrome , NLR Family, Pyrin Domain-Containing 3 Protein , Animals , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Interleukin-18/metabolism , Interleukin-18/blood , Inflammasomes/metabolism , Macrophage Activation Syndrome/blood , Macrophage Activation Syndrome/pathology , Macrophage Activation Syndrome/complications , Caspase 1/metabolism , Mice , Mice, Inbred C57BL , Carrier Proteins/metabolism , Oligodeoxyribonucleotides/pharmacology , Interleukin 1 Receptor Antagonist Protein/blood , Interleukin 1 Receptor Antagonist Protein/metabolism , Receptors, Interleukin-1/metabolismABSTRACT
The IL-17 pathway displays remarkably diverse functional modes between different subphyla, classes, and even orders, yet its driving factors remains elusive. Here, we demonstrate that the IL-17 pathway originated through domain shuffling between a Toll-like receptor (TLR)/IL-1R pathway and a neurotrophin-RTK (receptor-tyrosine-kinase) pathway (a Trunk-Torso pathway). Unlike other new pathways that evolve independently, the IL-17 pathway remains intertwined with its donor pathways throughout later evolution. This intertwining not only influenced the gains and losses of domains and components in the pathway but also drove the diversification of the pathway's functional modes among animal lineages. For instance, we reveal that the crustacean female sex hormone, a neurotrophin inducing sex differentiation, could interact with IL-17Rs and thus be classified as true IL-17s. Additionally, the insect prothoracicotropic hormone, a neurotrophin initiating ecdysis in Drosophila by binding to Torso, could bind to IL-17Rs in other insects. Furthermore, IL-17R and TLR/IL-1R pathways maintain crosstalk in amphioxus and zebrafish. Moreover, the loss of the Death domain in the pathway adaptor connection to IκB kinase and stress-activated protein kinase (CIKSs) dramatically reduced their abilities to activate nuclear factor-kappaB (NF-κB) and activator protein 1 (AP-1) in amphioxus and zebrafish. Reinstating this Death domain not only enhanced NF-κB/AP-1 activation but also strengthened anti-bacterial immunity in zebrafish larvae. This could explain why the mammalian IL-17 pathway, whose CIKS also lacks Death, is considered a weak signaling activator, relying on synergies with other pathways. Our findings provide insights into the functional diversity of the IL-17 pathway and unveil evolutionary principles that could govern the pathway and be used to redesign and manipulate it.
Subject(s)
Interleukin-17 , Signal Transduction , Toll-Like Receptors , Animals , Interleukin-17/metabolism , Toll-Like Receptors/metabolism , Nerve Growth Factors/metabolism , Nerve Growth Factors/genetics , Receptors, Interleukin-1/metabolism , Receptors, Interleukin-1/genetics , Evolution, Molecular , Receptors, Interleukin-17/metabolism , Receptors, Interleukin-17/geneticsSubject(s)
COVID-19 , Adult , Aged , Female , Humans , Male , Middle Aged , Biomarkers/blood , COVID-19/immunology , COVID-19/blood , Lipoproteins , Receptors, Interleukin-1/antagonists & inhibitors , SARS-CoV-2/immunologyABSTRACT
A recently characterized RNA modification is NAD+-modified RNAs (NAD-RNAs). Various enzymes decap NAD-RNAs, and Wang and Yu et al. now describe another, namely Toll/interleukin-1 receptor (TIR) domain-containing proteins of bacteria and Archaea. TIR decapping products are a specific variant of cyclic ADP ribose (ADPR)-RNAs (v-cADPR-RNAs), opening a new window to the NAD-RNA world.
Subject(s)
NAD , NAD/metabolism , Humans , Protein Domains , Receptors, Interleukin-1/metabolism , Receptors, Interleukin-1/chemistry , RNA/metabolism , RNA/chemistryABSTRACT
The purpose of this study was to explore the effects of regulatory B-cells (Breg) on intracranial aneurysms by mediating IL-1ß/IL-1R pathways. The study involved 60 patients undergoing angiography in a hospital from January to June 2022, divided into two groups: 30 with intracranial aneurysms (observation group) and 30 without (control group). Researchers extracted peripheral blood mononuclear cells (PBMC) to analyze the proportion of CD19+CD24hiCD38hiB cells using flow cytometry. These cells, along with T-cells and regulatory T-cells (Treg), were isolated through magnetic bead cell sorting. Following co-culture, the proliferation of T-cells and their related secretory factors were assessed. Additionally, Breg cells, treated with an IL-1R receptor blocker or IL-1R expression adenovirus, were studied to evaluate the levels of IL-10 and TGF-ß. In the study, the observation group showed lower levels of CD19+CD24hiCD38hiB cells, IL-10, and TGF-ß in PBMC than the control group (P<0.05). T-cell proportions were similar in both groups pre and post co-culture (P>0.05). Post co-culture, IFN-γ decreased while IL-4 increased in both groups. The observation group had higher IFN-γ and lower IL-4 than the control group (P<0.05). TNF-α in CD8+T cells, and granzyme B and perforin mRNA levels decreased post co-culture but were higher in the observation group (P<0.05). IL-10 and TGF-ß in Treg cells increased in both groups post co-culture but were lower in the observation group (P<0.05). The observation group also had fewer CD19+IL-1R+IL-10+B cells (P<0.05). After IL-1R blocker addition, IL-10 and TGF-ß in the supernatant decreased in the observation group (P<0.05). Following transfection, IL-1 and TGF-ß levels increased compared to the blank group (P<0.05). The function of peripheral blood CD19+CD24hiCD38hiB cells is impaired in patients with intracranial aneurysms, which may be related to IL-1ß/IL-1R pathways disorder.
Subject(s)
B-Lymphocytes, Regulatory , Interleukin-1beta , Intracranial Aneurysm , Receptors, Interleukin-1 , Female , Humans , Male , B-Lymphocytes, Regulatory/immunology , B-Lymphocytes, Regulatory/metabolism , Cell Proliferation , Coculture Techniques , Interleukin-10/metabolism , Interleukin-1beta/metabolism , Intracranial Aneurysm/immunology , Intracranial Aneurysm/pathology , Intracranial Aneurysm/metabolism , Leukocytes, Mononuclear/metabolism , Leukocytes, Mononuclear/immunology , Receptors, Interleukin-1/metabolism , Receptors, Interleukin-1/genetics , Signal Transduction , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes, Regulatory/metabolism , Transforming Growth Factor beta/metabolismABSTRACT
The interleukin 1 (IL-1) family plays a significant role in the innate immune response. IL-1 receptor 2 (IL-1R2) is the decoy receptor of IL-1. It is a negative regulator that can be subdivided into membrane-bound and soluble types. IL-1R2 plays a role in the IL-1 family mainly through the following mechanisms: formation of inactive signaling complexes upon binding to the receptor auxiliary protein and inhibition of ligand IL-1 maturation. This review covers the roles of IL-1R2 in kidney disorders. Chronic kidney disease, acute kidney injury, lupus nephritis, IgA nephropathy, renal clear cell carcinoma, rhabdoid tumor of kidney, kidney transplantation, and kidney infection were all shown to have abnormal IL-1R2 expression. IL-1R2 may be a potential marker and a promising therapeutic target for kidney disease.
Subject(s)
Kidney Diseases , Receptors, Interleukin-1 , Humans , Receptors, Interleukin-1 Type II/metabolism , Interleukin-1 , KidneyABSTRACT
BACKGROUND: Patients with fibro-calcific aortic valve disease (FCAVD) have lipid depositions in their aortic valve that engender a proinflammatory impetus toward fibrosis and calcification and ultimately valve leaflet stenosis. Although the lipoprotein(a)-autotaxin (ATX)-lysophosphatidic acid axis has been suggested as a potential therapeutic target to prevent the development of FCAVD, supportive evidence using ATX inhibitors is lacking. We here evaluated the therapeutic potency of an ATX inhibitor to attenuate valvular calcification in the FCAVD animal models. METHODS: ATX level and activity in healthy participants and patients with FCAVD were analyzed using a bioinformatics approach using the Gene Expression Omnibus datasets, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, and western blotting. To evaluate the efficacy of ATX inhibitor, interleukin-1 receptor antagonist-deficient (Il1rn-/-) mice and cholesterol-enriched diet-induced rabbits were used as the FCAVD models, and primary human valvular interstitial cells (VICs) from patients with calcification were employed. RESULTS: The global gene expression profiles of the aortic valve tissue of patients with severe FCAVD demonstrated that ATX gene expression was significantly upregulated and correlated with lipid retention (r = 0.96) or fibro-calcific remodeling-related genes (r = 0.77) in comparison to age-matched non-FCAVD controls. Orally available ATX inhibitor, BBT-877, markedly ameliorated the osteogenic differentiation and further mineralization of primary human VICs in vitro. Additionally, ATX inhibition significantly attenuated fibrosis-related factors' production, with a detectable reduction of osteogenesis-related factors, in human VICs. Mechanistically, ATX inhibitor prohibited fibrotic changes in human VICs via both canonical and non-canonical TGF-ß signaling, and subsequent induction of CTGF, a key factor in tissue fibrosis. In the in vivo FCAVD model system, ATX inhibitor exposure markedly reduced calcific lesion formation in interleukin-1 receptor antagonist-deficient mice (Il1rn-/-, P = 0.0210). This inhibition ameliorated the rate of change in the aortic valve area (P = 0.0287) and mean pressure gradient (P = 0.0249) in the FCAVD rabbit model. Moreover, transaortic maximal velocity (Vmax) was diminished with ATX inhibitor administration (mean Vmax = 1.082) compared to vehicle control (mean Vmax = 1.508, P = 0.0221). Importantly, ATX inhibitor administration suppressed the effects of a high-cholesterol diet and vitamin D2-driven fibrosis, in association with a reduction in macrophage infiltration and calcific deposition, in the aortic valves of this rabbit model. CONCLUSIONS: ATX inhibition attenuates the development of FCAVD while protecting against fibrosis and calcification in VICs, suggesting the potential of using ATX inhibitors to treat FCAVD.
Subject(s)
Aortic Valve Stenosis , Aortic Valve/pathology , Calcinosis , Humans , Animals , Mice , Rabbits , Aortic Valve Stenosis/drug therapy , Osteogenesis , Calcinosis/drug therapy , Cells, Cultured , Fibrosis , Cholesterol , Receptors, Interleukin-1 , LipidsABSTRACT
Plant nucleotide-binding leucine-rich repeat (NLR) immune receptors with an N-terminal Toll/interleukin-1 receptor (TIR) domain mediate recognition of strain-specific pathogen effectors, typically via their C-terminal ligand-sensing domains1. Effector binding enables TIR-encoded enzymatic activities that are required for TIR-NLR (TNL)-mediated immunity2,3. Many truncated TNL proteins lack effector-sensing domains but retain similar enzymatic and immune activities4,5. The mechanism underlying the activation of these TIR domain proteins remain unclear. Here we show that binding of the TIR substrates NAD+ and ATP induces phase separation of TIR domain proteins in vitro. A similar condensation occurs with a TIR domain protein expressed via its native promoter in response to pathogen inoculation in planta. The formation of TIR condensates is mediated by conserved self-association interfaces and a predicted intrinsically disordered loop region of TIRs. Mutations that disrupt TIR condensates impair the cell death activity of TIR domain proteins. Our data reveal phase separation as a mechanism for the activation of TIR domain proteins and provide insight into substrate-induced autonomous activation of TIR signalling to confer plant immunity.
Subject(s)
Adenosine Triphosphate , Arabidopsis , NAD , Nicotiana , Phase Separation , Plant Proteins , Protein Domains , Adenosine Triphosphate/metabolism , Arabidopsis/genetics , Arabidopsis/immunology , Arabidopsis/metabolism , Arabidopsis Proteins/chemistry , Arabidopsis Proteins/genetics , Arabidopsis Proteins/immunology , Arabidopsis Proteins/metabolism , Cell Death , Mutation , NAD/metabolism , Nicotiana/genetics , Nicotiana/immunology , Nicotiana/metabolism , NLR Proteins/chemistry , NLR Proteins/genetics , NLR Proteins/immunology , NLR Proteins/metabolism , Plant Diseases/immunology , Plant Immunity/genetics , Plant Proteins/chemistry , Plant Proteins/genetics , Plant Proteins/immunology , Plant Proteins/metabolism , Promoter Regions, Genetic , Protein Domains/genetics , Receptors, Immunologic/chemistry , Receptors, Immunologic/genetics , Receptors, Immunologic/immunology , Receptors, Immunologic/metabolism , Signal Transduction , Toll-Like Receptors/chemistry , Receptors, Interleukin-1/chemistryABSTRACT
The occurrence of NAD+ as a non-canonical RNA cap has been demonstrated in diverse organisms. TIR domain-containing proteins present in all kingdoms of life act in defense responses and can have NADase activity that hydrolyzes NAD+. Here, we show that TIR domain-containing proteins from several bacterial and one archaeal species can remove the NAM moiety from NAD-capped RNAs (NAD-RNAs). We demonstrate that the deNAMing activity of AbTir (from Acinetobacter baumannii) on NAD-RNA specifically produces a cyclic ADPR-RNA, which can be further decapped in vitro by known decapping enzymes. Heterologous expression of the wild-type but not a catalytic mutant AbTir in E. coli suppressed cell propagation and reduced the levels of NAD-RNAs from a subset of genes before cellular NAD+ levels are impacted. Collectively, the in vitro and in vivo analyses demonstrate that TIR domain-containing proteins can function as a deNAMing enzyme of NAD-RNAs, raising the possibility of TIR domain proteins acting in gene expression regulation.
Subject(s)
Escherichia coli , NAD , NAD/metabolism , Escherichia coli/genetics , Escherichia coli/metabolism , Bacteria/genetics , RNA Caps/metabolism , Receptors, Interleukin-1ABSTRACT
IL-36 is known to mediate inflammation and fibrosis. Nevertheless, IL-36 signalling axis has also been implicated in cancer, although understanding of exact contribution of IL-36 to cancer progression is very limited, partly due to existence of multiple IL-36 ligands with agonistic and antagonistic function. Here we explored the role of IL-36 in oral squamous cell carcinoma (OSCC). Firstly, we analyzed expression of IL-36 ligands and receptor and found that the expression of IL-36γ was significantly higher in head and neck cancer (HNSCC) than that of normal tissues, and that the high expression of IL-36γ predicted poor clinical outcomes. Secondly, we investigated the direct effect of IL-36γ on OSCC cells and found that IL-36γ stimulated proliferation of OSCC cells with high expression of IL-36R expression. Interestingly, IL-36γ also promoted migration of OSCC cells with low to high IL-36R expression. Critically, both proliferation and migration of OSCC cells induced by IL-36γ were abrogated by anti-IL-36R mAb. Fittingly, RNA sequence analysis revealed that IL-36γ regulated genes involved in cell cycle and cell division. In summary, our results showed that IL-36γ can be a tumor-promoting factor, and targeting of IL-36R signalling may be a beneficial targeted therapy for patients with abnormal IL-36 signalling.
Subject(s)
Carcinoma, Squamous Cell , Head and Neck Neoplasms , Mouth Neoplasms , Humans , Interleukin-1/metabolism , Receptors, Interleukin-1/genetics , Receptors, Interleukin-1/metabolism , Squamous Cell Carcinoma of Head and Neck , Cell Proliferation , Cell Line, TumorABSTRACT
Toll-like receptor (TLR) innate immunity signalling protects against pathogens, but excessive or prolonged signalling contributes to a range of inflammatory conditions. Structural information on the TLR cytoplasmic TIR (Toll/interleukin-1 receptor) domains and the downstream adaptor proteins can help us develop inhibitors targeting this pathway. The small molecule o-vanillin has previously been reported as an inhibitor of TLR2 signalling. To study its mechanism of action, we tested its binding to the TIR domain of the TLR adaptor MAL/TIRAP (MALTIR). We show that o-vanillin binds to MALTIR and inhibits its higher-order assembly in vitro. Using NMR approaches, we show that o-vanillin forms a covalent bond with lysine 210 of MAL. We confirm in mouse and human cells that o-vanillin inhibits TLR2 but not TLR4 signalling, independently of MAL, suggesting it may covalently modify TLR2 signalling complexes directly. Reactive aldehyde-containing small molecules such as o-vanillin may target multiple proteins in the cell.
Subject(s)
Benzaldehydes , Lysine , Toll-Like Receptor 2 , Humans , Animals , Mice , Toll-Like Receptor 2/metabolism , Toll-Like Receptor 4/metabolism , Myeloid Differentiation Factor 88/metabolism , Toll-Like Receptors/metabolism , Membrane Glycoproteins/metabolism , Receptors, Interleukin-1/metabolismABSTRACT
Stroke is the leading cause of disability worldwide, yet there is currently no effective treatment available to mitigate its negative consequences. Pro-inflammatory cytokines, such as interleukin-1 (IL-1), are known to play a crucial role in exacerbating the aftermath of stroke. Thus, it is hypothesized that blocking inflammation and administering anti-inflammatory drugs at an optimal time and dosage may improve the long-term quality of life for stroke patients. This systematic review examines the effectiveness and safety of IL-1 receptor antagonist (IL-1Ra), commercially known as "anakinra," in clinical studies involving the treatment of stroke patients. A comprehensive literature search was conducted until October 2023 to identify relevant studies. The search yielded 1403 articles, out of which 598 were removed due to duplication. After a thorough review of 805 titles and abstracts, 797 articles were further excluded, resulting in 8 studies being included in this systematic review. The findings from all the included studies demonstrate that IL-1Ra is safe for use in acute ischemic and hemorrhagic stroke patients, with no significant adverse events reported. Additionally, biomarkers, clinical assessments, serious adverse events (AEs), and non-serious AEs consistently showed more favorable outcomes in IL-1Ra receiving patients. Stroke elevates the levels of several inflammatory cytokines, however, administration of IL-1RA directly or indirectly modulates these markers and improves some clinical outcomes, suggesting a potential therapeutic benefit of this intervention.
Subject(s)
Interleukin 1 Receptor Antagonist Protein , Stroke , Humans , Interleukin 1 Receptor Antagonist Protein/adverse effects , Quality of Life , Stroke/drug therapy , Cytokines , Receptors, Interleukin-1/therapeutic useABSTRACT
Soluble growth stimulation expressed gene 2 (sST2) is a new generation biomarker in the diagnosis and prognosis of heart failure (HF). Here, the sST2-specific aptamers were selected from a random ssDNA library with the full length of 88 nucleotides (nt) via target-immobilized magnetic beads (MB)-based systematic evolution of ligands by exponential enrichment (SELEX) technology. After eight rounds of selection, six aptamers with the most enrichment were selected. Among, the aptamer L1 showed the high-affinity binding to sST2 with the lowest Kd value (77.3 ± 0.05 nM), which was chosen as the optimal aptamer for further molecular docking. Then, the aptamer L1 was used to construct a graphene oxide (GO) - based fluorescence resonance energy transfer (FRET) biosensor for sST2, which exhibits a linear detection range of 0.1-100 µg/ml and a detection limit of 3.7 ng/ml. The aptasensor was applied to detect sST2 in real samples, with a good correlation and agreement with the traditional enzyme-linked immunosorbent assay (ELISA) when quantitative analyzing the sST2 concentration in serum samples from HF patients. The results show that not only an efficient strategy for screening the practicable aptamer, but also a rapid and sensitive detection platform for sST2 were established.