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Background: Insufficiently managed incisional (INC) pain severely affects patients' life quality and rehabilitation after a major operation. However, mechanisms underlying INC pain still remain poorly understood. Methods: A mouse model of INC pain was established by skin plus deep muscle incision. Biochemistry assay, in vivo reactive oxygen species (ROS) imaging, Ca2+ imaging combined with retrograde labelling, neuron tracing and nocifensive behavior test, etc. were utilized for mechanism investigation. Results: We found pro-nociceptive cytokine interleukin -33 (IL-33) ranked among top up-regulated cytokines in incised tissues of INC pain model mice. IL-33 was predominantly expressed in keratinocytes around the incisional area. Neutralization of IL-33 or its receptor suppression of tumorigenicity 2 protein (ST2) or genetic deletion of St2 gene (St2 -/-) remarkably ameliorated mechanical allodynia and improved gait impairments of model mice. IL-33 contributes to INC pain by recruiting macrophages, which subsequently release ROS in incised tissues via ST2-dependent mechanism. Transfer of excessive macrophages enhanced oxidative injury and reproduced mechanical allodynia in St2 -/- mice upon tissue incision. Overproduced ROS subsequently activated functionally up-regulated transient receptor potential ankyrin subtype-1 (TRPA1) channel innervating the incisional site to produce mechanical allodynia. Neither deleting St2 nor attenuating ROS affected wound healing of model mice. Conclusions: Our work uncovered a previously unrecognized contribution of IL-33/ST2 signaling in mediating mechanical allodynia and gait impairment of a mouse model of INC pain. Targeting IL-33/ST2 signaling could be a novel therapeutic approach for INC pain management.
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Modelos Animales de Enfermedad , Hiperalgesia , Proteína 1 Similar al Receptor de Interleucina-1 , Interleucina-33 , Macrófagos , Ratones Noqueados , Especies Reactivas de Oxígeno , Canal Catiónico TRPA1 , Animales , Interleucina-33/metabolismo , Interleucina-33/genética , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Proteína 1 Similar al Receptor de Interleucina-1/genética , Especies Reactivas de Oxígeno/metabolismo , Ratones , Canal Catiónico TRPA1/metabolismo , Canal Catiónico TRPA1/genética , Macrófagos/metabolismo , Hiperalgesia/metabolismo , Piel/metabolismo , Masculino , Ratones Endogámicos C57BL , Queratinocitos/metabolismo , Dolor/metabolismoRESUMEN
Bronchopulmonary dysplasia (BPD) is a common complication of preterm birth. Despite this, genetic drivers of BPD are poorly understood. The objective of this study is to better understand the impact of single nucleotide polymorphisms (SNPs) previously associated with BPD by examining associations with other phenotypes. We drew pediatric subjects from the biorepository at the Center for Applied Genomics to identify associations between these SNPs and 2,146 imputed phenotypes. Methylation data, external cohorts, and in silico validation methods were used to corroborate significant associations. We identified 60 SNPs that were previously associated with BPD. We found a significant association between rs3771150 and rs3771171 and mean eosinophil percentage in a European cohort of 6,999 patients and replicated this in external cohorts. Both SNPs were also associated with asthma, COPD and FEV1/FVC ratio. These SNPs displayed associations with methylation probes and were functionally linked to ST2 (IL1RL1) levels in blood and lung tissue. Our findings support a genetic justification for the epidemiological link between BPD and asthma. Given the well-established link between ST2 and type 2 inflammation in asthma, these findings provide a rationale for future studies exploring the role of type 2 inflammation in the pathogenesis of BPD.
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Asma , Displasia Broncopulmonar , Eosinofilia , Fenotipo , Polimorfismo de Nucleótido Simple , Humanos , Displasia Broncopulmonar/genética , Displasia Broncopulmonar/patología , Masculino , Femenino , Eosinofilia/genética , Niño , Asma/genética , Proteína 1 Similar al Receptor de Interleucina-1/genética , Predisposición Genética a la Enfermedad , Recién Nacido , Estudio de Asociación del Genoma Completo , Preescolar , Metilación de ADN , LactanteRESUMEN
Eosinophils are involved in host protection against multicellular organisms. However, their recruitment to the mesenteric lymph node (mLN) during type 2 immunity is understudied. Our results demonstrate that eosinophil association with lymphoid stromal niches constructed by fibroblastic reticular cells (FRCs) and lymphatic endothelial cells is diminished in mice selectively lacking interleukin (IL)-4Rα or lymphotoxin-ß (LTß) expression on B cells. Furthermore, eosinophil survival, activation, and enhanced Il1rl1 receptor expression are driven by stromal cell and B cell dialogue. The ligation of lymphotoxin-ß receptor (LTßR) on FRCs improves eosinophil survival and significantly augments IL-33 expression and eosinophil homing to the mLN, thus confirming the significance of lymphotoxin signaling for granulocyte recruitment. Eosinophil-deficient ΔdblGATA-1 mice show diminished mLN expansion, reduced interfollicular region (IFR) alarmin expression, and delayed helminth clearance, elucidating their importance in type 2 immunity. These findings provide insight into dialogue between stromal cells and B cells, which govern mLN eosinophilia, and the relevance of these mechanisms during type 2 immunity.
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Linfocitos B , Eosinófilos , Interleucina-33 , Células del Estroma , Animales , Eosinófilos/inmunología , Eosinófilos/metabolismo , Células del Estroma/metabolismo , Células del Estroma/inmunología , Linfocitos B/inmunología , Linfocitos B/metabolismo , Interleucina-33/metabolismo , Ratones , Receptor beta de Linfotoxina/metabolismo , Ratones Endogámicos C57BL , Ganglios Linfáticos/inmunología , Comunicación Celular , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Proteína 1 Similar al Receptor de Interleucina-1/genética , Transducción de Señal , Receptores de Superficie CelularRESUMEN
Pericardial fluid (PF) has been suggested as a reservoir of molecular targets that can be modulated for efficient repair after myocardial infarction (MI). Here, we set out to address the content of this biofluid after MI, namely in terms of microRNAs (miRs) that are important modulators of the cardiac pathological response. PF was collected during coronary artery bypass grafting (CABG) from two MI cohorts, patients with non-ST-segment elevation MI (NSTEMI) and patients with ST-segment elevation MI (STEMI), and a control group composed of patients with stable angina and without previous history of MI. The PF miR content was analyzed by small RNA sequencing, and its biological effect was assessed on human cardiac fibroblasts. PF accumulates fibrotic and inflammatory molecules in STEMI patients, namely causing the soluble suppression of tumorigenicity 2 (ST-2), which inversely correlates with the left ventricle ejection fraction. Although the PF of the three patient groups induce similar levels of fibroblast-to-myofibroblast activation in vitro, RNA sequencing revealed that PF from STEMI patients is particularly enriched not only in pro-fibrotic miRs but also anti-fibrotic miRs. Among those, miR-22-3p was herein found to inhibit TGF-ß-induced human cardiac fibroblast activation in vitro. PF constitutes an attractive source for screening diagnostic/prognostic miRs and for unveiling novel therapeutic targets in cardiac fibrosis.
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Fibrosis , MicroARNs , Infarto del Miocardio , Líquido Pericárdico , Humanos , MicroARNs/genética , MicroARNs/metabolismo , Infarto del Miocardio/metabolismo , Infarto del Miocardio/genética , Infarto del Miocardio/patología , Masculino , Líquido Pericárdico/metabolismo , Femenino , Miocardio/metabolismo , Miocardio/patología , Persona de Mediana Edad , Fibroblastos/metabolismo , Anciano , Factor de Crecimiento Transformador beta/metabolismo , Infarto del Miocardio con Elevación del ST/metabolismo , Infarto del Miocardio con Elevación del ST/patología , Infarto del Miocardio con Elevación del ST/genética , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Proteína 1 Similar al Receptor de Interleucina-1/genéticaRESUMEN
Difamilast, a phosphodiesterase 4 (PDE4) inhibitor, has been shown to be effective in the treatment of atopic dermatitis (AD), although the mechanism involved remains unclear. Since IL-33 plays an important role in the pathogenesis of AD, we investigated the effect of difamilast on IL-33 activity. Since an in vitro model of cultured normal human epidermal keratinocytes (NHEKs) has been utilized to evaluate the pharmacological potential of adjunctive treatment of AD, we treated NHEKs with difamilast and analyzed the expression of the suppression of tumorigenicity 2 protein (ST2), an IL-33 receptor with transmembrane (ST2L) and soluble (sST2) isoforms. Difamilast treatment increased mRNA and protein levels of sST2, a decoy receptor suppressing IL-33 signal transduction, without affecting ST2L expression. Furthermore, supernatants from difamilast-treated NHEKs inhibited IL-33-induced upregulation of TNF-α, IL-5, and IL-13 in KU812 cells, a basophil cell line sensitive to IL-33. We also found that difamilast activated the aryl hydrocarbon receptor (AHR)-nuclear factor erythroid 2-related factor 2 (NRF2) axis. Additionally, the knockdown of AHR or NRF2 abolished the difamilast-induced sST2 production. These results indicate that difamilast treatment produces sST2 via the AHR-NRF2 axis, contributing to improving AD symptoms by inhibiting IL-33 activity.
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Proteína 1 Similar al Receptor de Interleucina-1 , Interleucina-33 , Queratinocitos , Factor 2 Relacionado con NF-E2 , Inhibidores de Fosfodiesterasa 4 , Receptores de Hidrocarburo de Aril , Transducción de Señal , Humanos , Factor 2 Relacionado con NF-E2/metabolismo , Queratinocitos/metabolismo , Queratinocitos/efectos de los fármacos , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Proteína 1 Similar al Receptor de Interleucina-1/genética , Receptores de Hidrocarburo de Aril/metabolismo , Receptores de Hidrocarburo de Aril/antagonistas & inhibidores , Inhibidores de Fosfodiesterasa 4/farmacología , Interleucina-33/metabolismo , Transducción de Señal/efectos de los fármacos , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Línea CelularRESUMEN
OBJECTIVES: Interleukin 33 (IL-33) is a crucial inflammatory factor that functions as an alarm signal in endometriosis (EMs). Epithelial-mesenchymal transition (EMT), a process related to inflammatory signals, intracellular reactive oxygen species (ROS) production, and lipid peroxidation, have been proposed as potential mechanisms that contribute to the development and progression of EMs. IL-33 is highly upregulated in the ectopic milieu. Moreover, ectopic endometrial cells constitutively express interleukin-33 receptor ST2 (IL-33R). However, the role of IL-33/ST2 in the EMT of EMs remains largely unknown. In this study, we aimed to mechanistically determine the role of IL-33/ST2 in EMs-associated fibrosis. MATERIALS AND METHODS: We established a non-lethal oxidative stress model to explore the conditions that trigger IL-33 induction. We performed α-smooth muscle actin (α-SMA) protein detection, cell counting kit-8 (CCK-8) assays, and scratch assays to analyze the impact of IL-33 on primary endometrial stromal cells (ESCs) proliferation and invasion. Clinical samples from patients with or without EMs were subjected to immunohistochemical (IHC) and and immunofluorescence(IF) staining to assess the clinical relevance of IL-33 receptor ST2 and EMT-related proteins. Furthermore, we used the ectopic human endometrial epithelial cell line 12Z and normal human epithelial cell line EEC to evaluate the effects of IL-33 on Wnt/ß-catenin signaling. The effect of IL-33 on EMT-associated fibrosis was validated in vivo by intraperitoneal injections of IL-33 and antiST2. RESULTS: We observed that ectopic milieu, characterized by ROS, TGF-ß1, and high level of estrogen, triggers the secretion of IL-33 from ectopic ESCs. Ectopic endometrial lesions exhibited higher level of fibrotic characteristics and ST2 expression than that in the normal endometrium. Exogenous recombinant human (rhIL-33) enhanced ESC migration and survival. Similarly, 12Z cells displayed a higher degree of EMT characteristics with elevated expression of CCN4 and Fra-1, downstream target genes of the WNT/ß-catenin pathway, than that observed in EECs. Conversely, blocking IL-33 with neutralizing antibodies, knocking down ST2 or ß-catenin with siRNA, and ß-catenin dephosphorylation abolished its effects on EMT promotion. In vivo validation demonstrated that IL-33 significantly promotes EMs-related fibrosis through the activation of Wnt/ß-catenin signaling. CONCLUSION: Our data strongly support the vital role of the IL-33/ST2 pathway in EMs-associated fibrosis and emphasize the importance of the EMT in the pathophysiology of fibrosis. Targeting the IL-33/ST2/Wnt/ß-catenin axis may hold promise as a feasible therapeutic approach for controlling fibrosis in EMs.
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Endometriosis , Transición Epitelial-Mesenquimal , Proteína 1 Similar al Receptor de Interleucina-1 , Interleucina-33 , beta Catenina , Femenino , Endometriosis/metabolismo , Endometriosis/patología , Endometriosis/genética , Interleucina-33/metabolismo , Interleucina-33/genética , Transición Epitelial-Mesenquimal/genética , Humanos , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Proteína 1 Similar al Receptor de Interleucina-1/genética , beta Catenina/metabolismo , Animales , Fosforilación , Ratones , Endometrio/patología , Endometrio/metabolismo , Adulto , Proliferación Celular , Movimiento Celular , Transducción de SeñalAsunto(s)
Asma , Haplotipos , Proteína 1 Similar al Receptor de Interleucina-1 , Interleucina-33 , Células Th2 , Asma/genética , Asma/inmunología , Asma/metabolismo , Humanos , Interleucina-33/genética , Interleucina-33/metabolismo , Proteína 1 Similar al Receptor de Interleucina-1/genética , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Células Th2/inmunología , Interleucinas/genética , Interleucinas/metabolismo , Polimorfismo de Nucleótido Simple , Regulación de la Expresión GénicaRESUMEN
Rheumatoid arthritis (RA) is a systemic chronic autoimmune disease that primarily affects the joints and surrounding soft tissues, characterized by chronic inflammation and proliferation of the synovium. Various immune cells are involved in the pathophysiology of RA. The complex interplay of factors such as chronic inflammation, genetic susceptibility, dysregulation of serum antibody levels, among others, contribute to the complexity of the disease mechanism, disease activity, and treatment of RA. Recently, the cytokine storm leading to increased disease activity in RA has gained significant attention. Interleukin-33 (IL-33), a member of the IL-1 family, plays a crucial role in inflammation and immune regulation. ST2 (suppression of tumorigenicity 2 receptor), the receptor for IL-33, is widely expressed on the surface of various immune cells. When IL-33 binds to its receptor ST2, it activates downstream signaling pathways to exert immunoregulatory effects. In RA, IL-33 regulates the progression of the disease by modulating immune cells such as circulating monocytes, tissue-resident macrophages, synovial fibroblasts, mast cells, dendritic cells, neutrophils, T cells, B cells, endothelial cells, and others. We have summarized and analyzed these findings to elucidate the pathways through which IL-33 regulates RA. Furthermore, IL-33 has been detected in the synovium, serum, and synovial fluid of RA patients. Due to inconsistent research results, we conducted a meta-analysis on the association between serum IL-33, synovial fluid IL-33, and the risk of developing RA in patients. The pooled SMD was 1.29 (95% CI: 1.15-1.44), indicating that IL-33 promotes the onset and pathophysiological progression of RA. Therefore, IL-33 may serve as a biomarker for predicting the risk of developing RA and treatment outcomes. As existing drugs for RA still cannot address drug resistance in some patients, new therapeutic approaches are needed to alleviate the significant burden on RA patients and healthcare systems. In light of this, we analyzed the potential of targeting the IL-33/ST2-related signaling pathway to modulate immune cells associated with RA and alleviate inflammation. We also reviewed IL-33 and RA susceptibility-related single nucleotide polymorphisms, suggesting potential involvement of IL-33 and macrophage-related drug-resistant genes in RA resistance therapy. Our review elucidates the role of IL-33 in the pathophysiology of RA, offering new insights for the treatment of RA.
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Artritis Reumatoide , Interleucina-33 , Animales , Humanos , Artritis Reumatoide/inmunología , Proteína 1 Similar al Receptor de Interleucina-1/genética , Proteína 1 Similar al Receptor de Interleucina-1/inmunología , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Interleucina-33/inmunología , Transducción de Señal/inmunologíaRESUMEN
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.
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Receptores de Interleucina-1 , Animales , Ratones , Regulación de la Expresión Génica , Genes Reporteros , Sitios Genéticos , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Proteína 1 Similar al Receptor de Interleucina-1/genética , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores de Interleucina-1/metabolismo , Receptores de Interleucina-1/genética , Proteína Fluorescente Roja/genéticaRESUMEN
Severe asthma and sinus disease are consequences of type 2 inflammation (T2I), mediated by interleukin (IL)-33 signaling through its membrane-bound receptor, ST2. Soluble (s)ST2 reduces available IL-33 and limits T2I, but little is known about its regulation. We demonstrate that prostaglandin E2 (PGE2) drives production of sST2 to limit features of lung T2I. PGE2-deficient mice display diminished sST2. In humans with severe respiratory T2I, urinary PGE2 metabolites correlate with serum sST2. In mice, PGE2 enhanced sST2 secretion by mast cells (MCs). Mice lacking MCs, ST2 expression by MCs, or E prostanoid (EP)2 receptors by MCs showed reduced sST2 lung concentrations and strong T2I. Recombinant sST2 reduced T2I in mice lacking PGE2 or ST2 expression by MCs back to control levels. PGE2 deficiency also reversed the hyperinflammatory phenotype in mice lacking ST2 expression by MCs. PGE2 thus suppresses T2I through MC-derived sST2, explaining the severe T2I observed in low PGE2 states.
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Dinoprostona , Proteína 1 Similar al Receptor de Interleucina-1 , Interleucina-33 , Pulmón , Mastocitos , Ratones Noqueados , Animales , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Proteína 1 Similar al Receptor de Interleucina-1/genética , Mastocitos/inmunología , Mastocitos/metabolismo , Dinoprostona/metabolismo , Ratones , Interleucina-33/metabolismo , Humanos , Pulmón/inmunología , Pulmón/metabolismo , Pulmón/patología , Asma/inmunología , Asma/metabolismo , Subtipo EP2 de Receptores de Prostaglandina E/metabolismo , Ratones Endogámicos C57BL , Inflamación/inmunología , Femenino , Masculino , Transducción de Señal , Neumonía/inmunología , Neumonía/metabolismoRESUMEN
IL-22 plays a critical role in defending against mucosal infections, but how IL-22 production is regulated is incompletely understood. Here, we show that mice lacking IL-33 or its receptor ST2 (IL-1RL1) were more resistant to Streptococcus pneumoniae lung infection than wild-type animals and that single-nucleotide polymorphisms in IL33 and IL1RL1 were associated with pneumococcal pneumonia in humans. The effect of IL-33 on S. pneumoniae infection was mediated by negative regulation of IL-22 production in innate lymphoid cells (ILCs) but independent of ILC2s as well as IL-4 and IL-13 signaling. Moreover, IL-33's influence on IL-22-dependent antibacterial defense was dependent on housing conditions of the mice and mediated by IL-33's modulatory effect on the gut microbiota. Collectively, we provide insight into the bidirectional crosstalk between the innate immune system and the microbiota. We conclude that both genetic and environmental factors influence the gut microbiota, thereby impacting the efficacy of antibacterial immune defense and susceptibility to pneumonia.
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Inmunidad Innata , Proteína 1 Similar al Receptor de Interleucina-1 , Interleucina-22 , Interleucina-33 , Interleucinas , Streptococcus pneumoniae , Animales , Interleucina-33/inmunología , Interleucina-33/genética , Interleucina-33/metabolismo , Interleucinas/metabolismo , Interleucinas/inmunología , Interleucinas/genética , Ratones , Streptococcus pneumoniae/inmunología , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Proteína 1 Similar al Receptor de Interleucina-1/genética , Proteína 1 Similar al Receptor de Interleucina-1/inmunología , Humanos , Ratones Noqueados , Microbiota/inmunología , Ratones Endogámicos C57BL , Neumonía Neumocócica/inmunología , Neumonía Neumocócica/microbiología , Microbioma Gastrointestinal/inmunología , Linfocitos/inmunología , Linfocitos/metabolismo , Polimorfismo de Nucleótido SimpleRESUMEN
Interleukin-33 (IL-33), secreted by astrocytes, regulates the synapse development in the spinal cord and hippocampus and suppresses autoimmune disease in the central nervous system (CNS). However, the mechanism of unconventional protein secretion of this cytokine remains unclear. In this study, we found that IFN-γ promotes the active secretion of IL-33 from astrocytes, and the active secretion of IL-33 from cytoplasm to extracellular space was dependent on interaction with transmembrane emp24 domain 10 (TMED10) via the IL-1 like cytokine domain in astrocytes. Knockout of Il-33 or its receptor St2 induced hippocampal astrocyte activation and depressive-like disorder in naive mice, as well as increased spinal cord astrocyte activation and polarization to a neurotoxic reactive subtype and aggravated passive experimental autoimmune encephalomyelitis (EAE). Our results have identified that IL-33 is actively secreted by astrocytes through the unconventional protein secretion pathway facilitated by TMED10 channels. This process helps maintain CNS homeostasis by inhibiting astrocyte activation.
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Astrocitos , Encefalomielitis Autoinmune Experimental , Homeostasis , Interleucina-33 , Ratones Endogámicos C57BL , Ratones Noqueados , Animales , Ratones , Astrocitos/metabolismo , Sistema Nervioso Central/metabolismo , Encefalomielitis Autoinmune Experimental/metabolismo , Hipocampo/metabolismo , Homeostasis/fisiología , Interferón gamma/metabolismo , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Proteína 1 Similar al Receptor de Interleucina-1/genética , Interleucina-33/metabolismo , Proteínas de la Membrana/metabolismo , Médula Espinal/metabolismoRESUMEN
Allergic airway inflammation results from uncontrolled immune responses to environmental Ags. Although it is well established that allergic immune responses exhibit a high degree of diversity, driven by primary effector cell types such as eosinophils, neutrophils, or CD4 T cells with distinct effector signatures, the mechanisms responsible for such pathogenesis remain elusive. Foxp3+ regulatory T cells (Tregs) are essential immune regulators during chronic inflammation, including allergic airway inflammation. Emerging evidence suggests that Tregs infiltrating inflamed tissues exhibit distinct phenotypes dependent on the specific tissue sites and can display heterogeneity and tissue residency. Whether diverse allergic airway inflammatory responses influence infiltrating Treg heterogeneity or Treg lung residency has not been explored. We employed an unbiased single-cell RNA sequencing approach to investigate lung-infiltrating Tregs in models of eosinophilic and neutrophilic airway inflammation. We found that lung-infiltrating Tregs are highly heterogeneous, and that Tregs displaying lung-resident phenotypes are significantly different depending on the types of inflammation. Treg expression of ST2, a receptor for alarmin IL-33, was predominantly associated with eosinophilic inflammation and tissue residency. Nevertheless, Treg-specific ST2 deficiency did not affect the development of eosinophilic allergic inflammation or the generation of lung-resident Tregs. These results uncover a stark heterogeneity among Tregs infiltrating the lungs during allergic airway inflammation. The results indicate that varying types of inflammation may give rise to phenotypically distinct lung-resident Tregs, underscoring a (to our knowledge) novel mechanism by which inflammatory cues may shape the composition of infiltrating Tregs, allowing them to regulate inflammatory responses through tissue-adapted mechanisms.
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Eosinófilos , Pulmón , Neutrófilos , Análisis de la Célula Individual , Linfocitos T Reguladores , Linfocitos T Reguladores/inmunología , Animales , Ratones , Neutrófilos/inmunología , Eosinófilos/inmunología , Pulmón/inmunología , Pulmón/patología , Ratones Endogámicos C57BL , Proteína 1 Similar al Receptor de Interleucina-1/genética , Proteína 1 Similar al Receptor de Interleucina-1/inmunología , Ratones Noqueados , Inflamación/inmunología , Modelos Animales de Enfermedad , Interleucina-33/inmunología , Eosinofilia/inmunología , Eosinofilia/patologíaRESUMEN
The ST2/IL-33 signaling pathway has an important role in the host inflammatory response. Here we aimed to study the association of ST2 and IL-33 polymorphisms with serum soluble (s) ST2 and IL-33 concentrations in healthy Finnish children and, in addition, their association with childhood asthma. In total, 146 children were followed from birth to the age 7 years for the development of asthma. Single-nucleotide polymorphisms (SNPs) in ST2 and IL-33 were determined, and associations of the SNP variants with serum levels of sST2 and IL-33 at age of 13 months and with recurrent wheezing and childhood asthma at 7 years of age were analyzed. Children with ST2 rs1041973 AC/AA genotypes had significantly lower level of serum sST2 (2453 pg/mL; IQR 2265) than those with CC genotype (5437 pg/mL; IQR 2575; p = < 0.0001). Similar difference was also observed with ST2 rs13408661. No differences were observed between subjects with studied IL-33 SNPs. Children who carried genetic variants of ST2 rs1041973 or rs13408661 seemed to have a higher risk of asthma. In contrast, children who carried genetic variants of IL-33 rs12551268 were less often diagnosed with asthma. Even though these SNPs seemed to associate with asthma, the differences were not statistically significant.
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Asma , Predisposición Genética a la Enfermedad , Proteína 1 Similar al Receptor de Interleucina-1 , Interleucina-33 , Polimorfismo de Nucleótido Simple , Humanos , Asma/genética , Interleucina-33/genética , Interleucina-33/sangre , Proteína 1 Similar al Receptor de Interleucina-1/genética , Proteína 1 Similar al Receptor de Interleucina-1/sangre , Finlandia/epidemiología , Femenino , Masculino , Niño , Preescolar , Estudios Prospectivos , Lactante , Recién Nacido , Cohorte de Nacimiento , Ruidos Respiratorios/genéticaRESUMEN
The cellular and molecular mechanisms of atherosclerosis are still unclear. Type 2 innate lymphocytes (ILC2) exhibit anti-inflammatory properties and protect against atherosclerosis. This study aimed to elucidate the pathogenesis of atherosclerosis development using atherosclerosis model mice (ApoE KO mice) and mice deficient in IL-33 receptor ST2 (ApoEST2 DKO mice). Sixteen-week-old male ApoE KO and ApoEST2 DKO mice were subjected to an 8-week regimen of a high-fat, high-sucrose diet. Atherosclerotic foci were assessed histologically at the aortic valve ring. Chronic inflammation was assessed using flow cytometry and real-time polymerase chain reaction. In addition, saturated fatty acids (palmitic acid) and IL-33 were administered to human aortic endothelial cells (HAECs) to assess fatty acid metabolism. ApoEST2 DKO mice with attenuated ILC2 had significantly worse atherosclerosis than ApoE KO mice. The levels of saturated fatty acids, including palmitic acid, were significantly elevated in the arteries and serum of ApoEST2 DKO mice. Furthermore, on treating HAECs with saturated fatty acids with or without IL-33, the Oil Red O staining area significantly decreased in the IL-33-treated group compared to that in the non-treated group. IL-33 potentially prevented the accumulation of saturated fatty acids within atherosclerotic foci.
Asunto(s)
Aterosclerosis , Ácidos Grasos , Interleucina-33 , Ratones Noqueados , Animales , Interleucina-33/metabolismo , Interleucina-33/genética , Aterosclerosis/metabolismo , Masculino , Ratones , Ácidos Grasos/metabolismo , Humanos , Modelos Animales de Enfermedad , Ácido Palmítico/farmacología , Apolipoproteínas E/genética , Apolipoproteínas E/deficiencia , Dieta Alta en Grasa , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Proteína 1 Similar al Receptor de Interleucina-1/genética , Células Endoteliales/metabolismo , Ratones Noqueados para ApoE , Linfocitos/metabolismo , Ratones Endogámicos C57BL , Aorta/metabolismo , Aorta/patología , Inmunidad InnataRESUMEN
BACKGROUND: The regenerative and adaptive capacity of skeletal muscles reduces with age, leading to severe disability and frailty in the elderly. Therefore, development of effective therapeutic interventions for muscle wasting is important both medically and socioeconomically. In the present study, we aimed to elucidate the potential contribution of fibro-adipogenic progenitors (FAPs), which are mesenchymal stem cells in skeletal muscles, to immobilization-induced muscle atrophy. METHODS: Young (2-3 months), adult (12-14 months), and aged (20-22 months) mice were used for analysis. Muscle atrophy was induced by immobilizing the hind limbs with a steel wire. FAPs were isolated from the hind limbs on days 0, 3, and 14 after immobilization for transcriptome analysis. The expression of ST2 and IL-33 in FAPs was evaluated by flow cytometry and immunostaining, respectively. To examine the role of IL-33-ST2 signaling in vivo, we intraperitoneally administered recombinant IL-33 or soluble ST2 (sST2) twice a week throughout the 2-week immobilization period. After 2-week immobilization, the tibialis anterior muscles were harvested and the cross-sectional area of muscle fibers was evaluated. RESULTS: The number of FAPs increased with the progression of muscle atrophy after immobilization in all age-groups. Transcriptome analysis of FAPs collected before and after immobilization revealed that Il33 and Il1rl1 transcripts, which encode the IL-33 receptor ST2, were transiently induced in young mice and, to a lesser extent, in aged mice. The number of FAPs positive for ST2 increased after immobilization in young mice. The number of ST2-positive FAPs also increased after immobilization in aged mice, but the difference from the baseline was not statistically significant. Immunostaining for IL-33 in the muscle sections revealed a significant increase in the number of FAPs expressing IL-33 after immobilization. Administration of recombinant IL-33 suppressed immobilization-induced muscle atrophy in aged mice but not in young mice. CONCLUSIONS: Our data reveal a previously unknown protective role of IL-33-ST2 signaling against immobilization-induced muscle atrophy in FAPs and suggest that IL-33-ST2 signaling is a potential new therapeutic target for alleviating disuse muscle atrophy, particularly in older adults.
Asunto(s)
Proteína 1 Similar al Receptor de Interleucina-1 , Interleucina-33 , Humanos , Anciano , Ratones , Animales , Interleucina-33/metabolismo , Proteína 1 Similar al Receptor de Interleucina-1/genética , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Adipogénesis , Músculo Esquelético/metabolismo , Atrofia Muscular/etiología , Atrofia Muscular/prevención & control , Atrofia Muscular/metabolismo , Diferenciación Celular/fisiologíaRESUMEN
Periodontitis, which is induced by repeated bacterial invasion and the ensuing immune reactions that follow, is the leading cause of tooth loss. Periodontal tissue is comprised of four different components, each with potential role in pathogenesis, however, most studies on immune responses focus on gingival tissue. Here, we present a modified ligature-induced periodontitis model in male mice to analyze the pathogenesis, which captures the complexity of periodontal tissue. We find that the inflammatory response in the peri-root tissues and the expression of IL-6 and RANKL by Thy-1.2- fibroblasts/stromal cells are prominent throughout the bone destruction phase, and present already at an early stage. The initiation phase is characterized by high levels of ST2 (encoded by Il1rl1) expression in the peri-root tissue, suggesting that the IL-33/ST2 axis is involved in the pathogenesis. Both Il1rl1- and Il33-deficient mice exhibit exacerbated bone loss in the acute phase of periodontitis, along with macrophage polarization towards a classically activated phenotype and increased neutrophil infiltration, indicating a protective role of the IL-33/ST2 axis in acute inflammation. Thus, our findings highlight the hidden role of the peri-root tissue and simultaneously advance our understanding of the etiology of periodontitis via implicating the IL-33/ST2 axis.
Asunto(s)
Pérdida de Hueso Alveolar , Periodontitis , Animales , Masculino , Ratones , Inflamación/metabolismo , Proteína 1 Similar al Receptor de Interleucina-1/genética , Interleucina-33/genéticaRESUMEN
BACKGROUND: Eosinophilic esophagitis (EoE) is an increasingly common inflammatory condition of the esophagus; however, the underlying immunologic mechanisms remain poorly understood. The epithelium-derived cytokine IL-33 is associated with type 2 immune responses and elevated in esophageal biopsy specimens from patients with EoE. OBJECTIVE: We hypothesized that overexpression of IL-33 by the esophageal epithelium would promote the immunopathology of EoE. METHODS: We evaluated the functional consequences of esophageal epithelial overexpression of a secreted and active form of IL-33 in a novel transgenic mouse, EoE33. EoE33 mice were analyzed for clinical and immunologic phenotypes. Esophageal contractility was assessed. Epithelial cytokine responses were analyzed in three-dimensional organoids. EoE33 phenotypes were further characterized in ST2-/-, eosinophil-deficient, and IL-13-/- mice. Finally, EoE33 mice were treated with dexamethasone. RESULTS: EoE33 mice displayed ST2-dependent, EoE-like pathology and failed to thrive. Esophageal tissue remodeling and inflammation included basal zone hyperplasia, eosinophilia, mast cells, and TH2 cells. Marked increases in levels of type 2 cytokines, including IL-13, and molecules associated with immune responses and tissue remodeling were observed. Esophageal organoids suggested reactive epithelial changes. Genetic deletion of IL-13 in EoE33 mice abrogated pathologic changes in vivo. EoE33 mice were responsive to steroids. CONCLUSIONS: IL-33 overexpression by the esophageal epithelium generated immunopathology and clinical phenotypes resembling human EoE. IL-33 may play a pivotal role in the etiology of EoE by activating the IL-13 pathway. EoE33 mice are a robust experimental platform for mechanistic investigation and translational discovery.
Asunto(s)
Esofagitis Eosinofílica , Interleucina-13 , Interleucina-33 , Animales , Humanos , Ratones , Modelos Animales de Enfermedad , Esofagitis Eosinofílica/inmunología , Esofagitis Eosinofílica/genética , Esofagitis Eosinofílica/patología , Eosinófilos/inmunología , Mucosa Esofágica/patología , Mucosa Esofágica/inmunología , Esófago/patología , Esófago/inmunología , Proteína 1 Similar al Receptor de Interleucina-1/genética , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Interleucina-13/genética , Interleucina-13/inmunología , Interleucina-13/metabolismo , Interleucina-33/genética , Interleucina-33/inmunología , Interleucina-33/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones TransgénicosRESUMEN
IL-33 is an inflammatory cytokine that promotes allergic disease by activating group 2 innate lymphoid cells, Th2 cells, and mast cells. IL-33 is increased in asthmatics, and its blockade suppresses asthma-like inflammation in mouse models. Homeostatic control of IL-33 signaling is poorly understood. Because the IL-33 receptor, ST2, acts via cascades used by the TLR family, similar feedback mechanisms may exist. MicroRNA (miR)-146a is induced by LPS-mediated TLR4 signaling and serves as a feedback inhibitor. Therefore, we explored whether miR-146a has a role in IL-33 signaling. IL-33 induced cellular and exosomal miR-146a expression in mouse bone marrow-derived mast cells (BMMCs). BMMCs transfected with a miR-146a antagonist or derived from miR-146a knockout mice showed enhanced cytokine expression in response to IL-33, suggesting that miR-146a is a negative regulator of IL-33-ST2 signaling. In vivo, miR-146a expression in plasma exosomes was elevated after i.p. injection of IL-33 in wild-type but not mast cell-deficient KitW-sh/W-sh mice. Finally, KitW-sh/W-sh mice acutely reconstituted with miR-146a knockout BMMCs prior to IL-33 challenge had elevated plasma IL-6 levels compared with littermates receiving wild-type BMMCs. These results support the hypothesis that miR-146a is a feedback regulator of IL-33-mediated mast cell functions associated with allergic disease.
Asunto(s)
Asma , MicroARNs , Animales , Ratones , Asma/genética , Citocinas/genética , Retroalimentación , Inmunidad Innata , Proteína 1 Similar al Receptor de Interleucina-1/genética , Interleucina-33 , Linfocitos/metabolismo , Mastocitos/metabolismo , Ratones Noqueados , MicroARNs/genética , MicroARNs/metabolismoRESUMEN
Lineage-specific effects of upstream promoters affect ST2 expression and effector function in TH1cells.