RESUMO
Mucosal-associated invariant T cells (MAIT cells) detect microbial vitamin B2 derivatives presented by the antigen-presenting molecule MR1. Here we defined three developmental stages and checkpoints for the MAIT cell lineage in humans and mice. Stage 1 and stage 2 MAIT cells predominated in thymus, while stage 3 cells progressively increased in abundance extrathymically. Transition through each checkpoint was regulated by MR1, whereas the final checkpoint that generated mature functional MAIT cells was controlled by multiple factors, including the transcription factor PLZF and microbial colonization. Furthermore, stage 3 MAIT cell populations were expanded in mice deficient in the antigen-presenting molecule CD1d, suggestive of a niche shared by MAIT cells and natural killer T cells (NKT cells). Accordingly, this study maps the developmental pathway and checkpoints that control the generation of functional MAIT cells.
Assuntos
Diferenciação Celular/imunologia , Células T Invariantes Associadas à Mucosa/citologia , Células T Invariantes Associadas à Mucosa/fisiologia , Timo/imunologia , Timo/metabolismo , Animais , Antígenos CD1d/genética , Biomarcadores , Diferenciação Celular/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Imunofenotipagem , Células Progenitoras Linfoides/imunologia , Células Progenitoras Linfoides/metabolismo , Masculino , Camundongos , Camundongos Knockout , MicroRNAs/genéticaRESUMO
Interleukin 37 (IL-37) and IL-1R8 (SIGIRR or TIR8) are anti-inflammatory orphan members of the IL-1 ligand family and IL-1 receptor family, respectively. Here we demonstrate formation and function of the endogenous ligand-receptor complex IL-37-IL-1R8-IL-18Rα. The tripartite complex assembled rapidly on the surface of peripheral blood mononuclear cells upon stimulation with lipopolysaccharide. Silencing of IL-1R8 or IL-18Rα impaired the anti-inflammatory activity of IL-37. Whereas mice with transgenic expression of IL-37 (IL-37tg mice) with intact IL-1R8 were protected from endotoxemia, IL-1R8-deficient IL-37tg mice were not. Proteomic and transcriptomic investigations revealed that IL-37 used IL-1R8 to harness the anti-inflammatory properties of the signaling molecules Mer, PTEN, STAT3 and p62(dok) and to inhibit the kinases Fyn and TAK1 and the transcription factor NF-κB, as well as mitogen-activated protein kinases. Furthermore, IL-37-IL-1R8 exerted a pseudo-starvational effect on the metabolic checkpoint kinase mTOR. IL-37 thus bound to IL-18Rα and exploited IL-1R8 to activate a multifaceted intracellular anti-inflammatory program.
Assuntos
Subunidade alfa de Receptor de Interleucina-18/imunologia , Interleucina-1/imunologia , Leucócitos Mononucleares/imunologia , Receptores de Interleucina-1/imunologia , Transdução de Sinais/imunologia , Animais , Linhagem Celular , Regulação da Expressão Gênica , Humanos , Imunidade Inata , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Interleucina-1/genética , Subunidade alfa de Receptor de Interleucina-18/antagonistas & inibidores , Subunidade alfa de Receptor de Interleucina-18/genética , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/patologia , Lipopolissacarídeos/farmacologia , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/imunologia , Camundongos , Camundongos Transgênicos , NF-kappa B/genética , NF-kappa B/imunologia , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/imunologia , Ligação Proteica , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/imunologia , Proteínas Proto-Oncogênicas c-fyn/genética , Proteínas Proto-Oncogênicas c-fyn/imunologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/imunologia , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/imunologia , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/imunologia , Receptores de Interleucina-1/antagonistas & inibidores , Receptores de Interleucina-1/deficiência , Receptores de Interleucina-1/genética , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/imunologia , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/imunologia , c-Mer Tirosina QuinaseRESUMO
BACKGROUND: Perinatal infection/inflammation is associated with a high risk for neurological injury and neurodevelopmental impairment after birth. Despite a growing preclinical evidence base, anti-inflammatory interventions have not been established in clinical practice, partly because of the range of potential targets. We therefore systematically reviewed preclinical studies of immunomodulation to improve neurological outcomes in the perinatal brain and assessed their therapeutic potential. METHODS: We reviewed relevant studies published from January 2012 to July 2023 using PubMed, Medline (OvidSP) and EMBASE databases. Studies were assessed for risk of bias using the SYRCLE risk of bias assessment tool (PROSPERO; registration number CRD42023395690). RESULTS: Forty preclinical publications using 12 models of perinatal neuroinflammation were identified and divided into 59 individual studies. Twenty-seven anti-inflammatory agents in 19 categories were investigated. Forty-five (76%) of 59 studies reported neuroprotection, from all 19 categories of therapeutics. Notably, 10/10 (100%) studies investigating anti-interleukin (IL)-1 therapies reported improved outcome, whereas half of the studies using corticosteroids (5/10; 50%) reported no improvement or worse outcomes with treatment. Most studies (49/59, 83%) did not control core body temperature (a known potential confounder), and 25 of 59 studies (42%) did not report the sex of subjects. Many studies did not clearly state whether they controlled for potential study bias. CONCLUSION: Anti-inflammatory therapies are promising candidates for treatment or even prevention of perinatal brain injury. Our analysis highlights key knowledge gaps and opportunities to improve preclinical study design that must be addressed to support clinical translation.
Assuntos
Anti-Inflamatórios , Neuroproteção , Gravidez , Animais , Feminino , Humanos , EncéfaloRESUMO
Preterm birth is a major contributor to neonatal morbidity and mortality. Complications of prematurity such as bronchopulmonary dysplasia (BPD, affecting the lung), pulmonary hypertension associated with BPD (BPD-PH, heart), white matter injury (WMI, brain), retinopathy of prematurity (ROP, eyes), necrotizing enterocolitis (NEC, gut) and sepsis are among the major causes of long-term morbidity in infants born prematurely. Though the origins are multifactorial, inflammation and in particular the imbalance of pro- and anti-inflammatory mediators is now recognized as a key driver of the pathophysiology underlying these illnesses. Here, we review the involvement of the interleukin (IL)-1 family in perinatal inflammation and its clinical implications, with a focus on the potential of these cytokines as therapeutic targets for the development of safe and effective treatments for early life inflammatory diseases.
Assuntos
Displasia Broncopulmonar , Doenças do Recém-Nascido , Nascimento Prematuro , Retinopatia da Prematuridade , Lactente , Gravidez , Feminino , Recém-Nascido , Humanos , Interleucina-1 , Recém-Nascido Prematuro , Anti-Inflamatórios/uso terapêutico , Displasia Broncopulmonar/etiologia , Displasia Broncopulmonar/tratamento farmacológico , Doenças do Recém-Nascido/tratamento farmacológico , Inflamação/complicações , Inflamação/tratamento farmacológico , Retinopatia da Prematuridade/tratamento farmacológicoRESUMO
The function of interleukin 37 (IL-37; formerly IL-1 family member 7) has remained elusive. Expression of IL-37 in macrophages or epithelial cells almost completely suppressed production of pro-inflammatory cytokines, whereas the abundance of these cytokines increased with silencing of endogenous IL-37 in human blood cells. Anti-inflammatory cytokines were unaffected. Mice with transgenic expression of IL-37 were protected from lipopolysaccharide-induced shock, and showed markedly improved lung and kidney function and reduced liver damage after treatment with lipopolysaccharide. Transgenic mice had lower concentrations of circulating and tissue cytokines (72-95% less) than wild-type mice and showed less dendritic cell activation. IL-37 interacted intracellularly with Smad3 and IL-37-expressing cells and transgenic mice showed less cytokine suppression when endogenous Smad3 was depleted. IL-37 thus emerges as a natural suppressor of innate inflammatory and immune responses.
Assuntos
Imunidade Inata/imunologia , Interleucina-1/imunologia , Animais , Linhagem Celular , Técnicas de Silenciamento de Genes , Humanos , Interleucina-1/genética , Camundongos , Camundongos Transgênicos , Transdução de Sinais , Proteína Smad3/imunologiaRESUMO
Bronchopulmonary dysplasia (BPD) is the most common respiratory sequela of prematurity, and infants born with fetal growth restriction (FGR) are disproportionately represented in BPD statistics, as factors which affect somatic growth may also affect pulmonary growth. Effects of in-utero hypoxia underlying FGR on lung parenchymal architecture predisposing to BPD are well documented, but the pulmonary vascular constructs are not well appreciated. Disruption of angiogenesis during critical periods of lung growth impairs alveolarization, contributing to BPD pathogenesis. Pulmonary artery thickness/stiffness has been noted in FGR in the initial postnatal weeks, and also in well-grown infants with established BPD. The lack of waveform cushioning by the major arteries exposes the pulmonary resistance vessels to higher pulsatile stress, thereby accelerating microvascular disease. Reactive oxygen species, increased sympathetic activity and endothelial dysfunction are common mediators in FGR and BPD; each putative targets for prevention and/or therapeutics using interleukin (IL)-1 receptor antagonist (IL-1Ra), melatonin or inhibition of renin-angiotensin-aldosterone system. While BPD is the archetypal respiratory disease of infancy, effects of FGR on pulmonary function are long-term, extending well into childhood. This narrative links FGR in very/extremely preterm infants with BPD through the vascular affliction as a mechanistic and potentially, therapeutic pathway. Our objectives were to depict the burden of disease for FGR and BPD amongst preterm infants, portray vascular involvement in the placenta in FGR and BPD cohorts, provide high resolution vascular ultrasound information in both cohorts with a view to address therapeutic relevance, and lastly, link this information with paediatric age-group lung diseases.
Assuntos
Displasia Broncopulmonar , Doenças do Recém-Nascido , Lactente , Gravidez , Feminino , Recém-Nascido , Humanos , Criança , Retardo do Crescimento Fetal , Pulmão , Lactente Extremamente PrematuroRESUMO
Oligonucleotide-based therapeutics have become a reality, and are set to transform management of many diseases. Nevertheless, the modulatory activities of these molecules on immune responses remain incompletely defined. Here, we show that gene targeting 2'-O-methyl (2'OMe) gapmer antisense oligonucleotides (ASOs) can have opposing activities on Toll-Like Receptors 7 and 8 (TLR7/8), leading to divergent suppression of TLR7 and activation of TLR8, in a sequence-dependent manner. Surprisingly, TLR8 potentiation by the gapmer ASOs was blunted by locked nucleic acid (LNA) and 2'-methoxyethyl (2'MOE) modifications. Through a screen of 192 2'OMe ASOs and sequence mutants, we characterized the structural and sequence determinants of these activities. Importantly, we identified core motifs preventing the immunosuppressive activities of 2'OMe ASOs on TLR7. Based on these observations, we designed oligonucleotides strongly potentiating TLR8 sensing of Resiquimod, which preserve TLR7 function, and promote strong activation of phagocytes and immune cells. We also provide proof-of-principle data that gene-targeting ASOs can be selected to synergize with TLR8 agonists currently under investigation as immunotherapies, and show that rational ASO selection can be used to prevent unintended immune suppression of TLR7. Taken together, our work characterizes the immumodulatory effects of ASOs to advance their therapeutic development.
Assuntos
Oligodesoxirribonucleotídeos Antissenso/farmacologia , Receptor 7 Toll-Like/metabolismo , Receptor 8 Toll-Like/metabolismo , Células Cultivadas , Humanos , Imidazóis/metabolismo , Leucócitos Mononucleares , Oligonucleotídeos/metabolismo , Receptor 7 Toll-Like/agonistas , Receptor 8 Toll-Like/agonistasRESUMO
BACKGROUND: Increased systemic and tissue levels of interleukin (IL)-1ß are associated with greater risk of impaired neurodevelopment after birth. In this study, we tested the hypothesis that systemic IL-1 receptor antagonist (Ra) administration would attenuate brain inflammation and injury in near-term fetal sheep exposed to lipopolysaccharide (LPS). METHODS: Chronically instrumented near-term fetal sheep at 0.85 of gestation were randomly assigned to saline infusion (control, n = 9), repeated LPS infusions (0 h = 300 ng, 24 h = 600 ng, 48 h = 1200 ng, n = 8) or repeated LPS plus IL-1Ra infusions (13 mg/kg infused over 4 h) started 1 h after each LPS infusion (n = 9). Sheep were euthanized 4 days after starting infusions for histology. RESULTS: LPS infusions increased circulating cytokines and were associated with electroencephalogram (EEG) suppression with transiently reduced mean arterial blood pressure, and increased carotid artery perfusion and fetal heart rate (P < 0.05 vs. control for all). In the periventricular and intragyral white matter, LPS-exposure increased IL-1ß immunoreactivity, numbers of caspase 3+ cells and microglia, reduced astrocyte and olig-2+ oligodendrocyte survival but did not change numbers of mature CC1+ oligodendrocytes, myelin expression or numbers of neurons in the cortex and subcortical regions. IL-1Ra infusions reduced circulating cytokines and improved recovery of EEG activity and carotid artery perfusion. Histologically, IL-1Ra reduced microgliosis, IL-1ß expression and caspase-3+ cells, and improved olig-2+ oligodendrocyte survival. CONCLUSION: IL-1Ra improved EEG activity and markedly attenuated systemic inflammation, microgliosis and oligodendrocyte loss following LPS exposure in near-term fetal sheep. Further studies examining the long-term effects on brain maturation are now needed.
Assuntos
Encéfalo/efeitos dos fármacos , Encefalite/tratamento farmacológico , Proteína Antagonista do Receptor de Interleucina 1/farmacologia , Lipopolissacarídeos/farmacologia , Oligodendroglia/efeitos dos fármacos , Substância Branca/efeitos dos fármacos , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Encefalite/metabolismo , Encefalite/patologia , Feminino , Proteína Antagonista do Receptor de Interleucina 1/uso terapêutico , Oligodendroglia/metabolismo , Oligodendroglia/patologia , Gravidez , Ovinos , Substância Branca/metabolismo , Substância Branca/patologiaRESUMO
Bronchopulmonary dysplasia (BPD) is a severe lung disease of preterm infants, which is characterized by fewer, enlarged alveoli and increased inflammation. BPD has grave consequences for affected infants, but no effective and safe therapy exists. We previously showed that prophylactic treatment with interleukin-1 receptor antagonist (IL-1Ra) prevents murine BPD induced by perinatal inflammation and hyperoxia. Here, we used the same BPD model to assess whether an alternative anti-inflammatory agent, protein C (PC), is as effective as IL-1Ra against BPD. We also tested whether delayed administration or a higher dose of IL-1Ra affects its ability to ameliorate BPD and investigated aspects of drug safety. Pups were reared in room air (21% O2 ) or hyperoxia (65% or 85% O2 ) and received daily injections with vehicle, 1200 IU/kg PC, 10 mg/kg IL-1Ra (early or late onset) or 100 mg/kg IL-1Ra. After 3 or 28 days, lung and brain histology were assessed and pulmonary cytokines were analysed using ELISA and cytokine arrays. We found that PC only moderately reduced the severe impact of BPD on lung structure (e.g. 18% increased alveolar number by PC versus 34% by IL-1Ra); however, PC significantly reduced IL-1ß, IL-1Ra, IL-6 and macrophage inflammatory protein (MIP)-2 by up to 89%. IL-1Ra at 10 mg/kg prevented BPD more effectively than 100 mg/kg IL-1Ra, but only if treatment commenced at day 1 of life. We conclude that prophylactic low-dose IL-1Ra and PC ameliorate BPD and have potential as the first remedy for one of the most devastating diseases preterm babies face.
Assuntos
Displasia Broncopulmonar/tratamento farmacológico , Inflamação/tratamento farmacológico , Proteína Antagonista do Receptor de Interleucina 1/administração & dosagem , Proteína C/administração & dosagem , Animais , Animais Recém-Nascidos , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/efeitos adversos , Displasia Broncopulmonar/complicações , Displasia Broncopulmonar/patologia , Modelos Animais de Doenças , Feminino , Humanos , Lactente , Recém-Nascido , Inflamação/complicações , Inflamação/patologia , Proteína Antagonista do Receptor de Interleucina 1/efeitos adversos , Pulmão/efeitos dos fármacos , Pulmão/patologia , Camundongos , Gravidez , Proteína C/efeitos adversos , Alvéolos Pulmonares/efeitos dos fármacos , Alvéolos Pulmonares/patologiaRESUMO
Harlequin ichthyosis (HI) is a severe skin disease which leads to neonatal death in â¼50% of cases. It is the result of mutations in ABCA12, a protein that transports lipids required to establish the protective skin barrier needed after birth. To better understand the life-threatening newborn HI phenotype, we analysed the developing epidermis for consequences of lipid dysregulation in mouse models. We observed a pro-inflammatory signature which was characterized by chemokine upregulation in embryonic skin which is distinct from that seen in other types of ichthyosis. Inflammation also persisted in grafted HI skin. To examine the contribution of inflammation to disease development, we overexpressed interleukin-37b to globally suppress fetal inflammation, observing considerable improvements in keratinocyte differentiation. These studies highlight inflammation as an unexpected contributor to HI disease development in utero, and suggest that inhibiting inflammation may reduce disease severity.
Assuntos
Ictiose Lamelar/embriologia , Ictiose Lamelar/imunologia , Animais , Diferenciação Celular , Quimiocinas/genética , Quimiocinas/imunologia , Modelos Animais de Doenças , Epiderme/embriologia , Epiderme/imunologia , Feminino , Humanos , Ictiose Lamelar/genética , Ictiose Lamelar/fisiopatologia , Interleucina-1/genética , Interleucina-1/imunologia , Queratinócitos/citologia , Masculino , Camundongos , Camundongos Knockout , Fenótipo , Pele/embriologia , Pele/imunologiaRESUMO
IL-37 is unique in the IL-1 family in that unlike other members of the family, IL-37 broadly suppresses innate immunity. IL-37 can be elevated in humans with inflammatory and autoimmune diseases where it likely functions to limit inflammation. Transgenic mice expressing human IL-37 (IL37-tg) exhibit less severe inflammation in models of endotoxin shock, colitis, myocardial infarction, lung, and spinal cord injury. IL37-tg mice have reduced antigen-specific responses and dendritic cells (DCs) from these mice exhibit characteristics of tolerogenic DCs. Compared to aging wild-type (WT) mice, aging IL37-tg mice are protected against B-cell leukemogenesis and heart failure. Treatment of WT mice with recombinant human IL-37 has been shown to be protective in several models of inflammation and injury. IL-37 binds to the IL-18 receptor but then recruits the orphan IL-1R8 (formerly TIR8 or SIGIRR) in order to function as an inhibitor. Here, we review the discovery of IL-37, its production, release, and mechanisms by which IL-37 reduces inflammation and suppresses immune responses. The data reviewed here suggest a therapeutic potential for IL-37.
Assuntos
Imunidade Inata , Inflamação/tratamento farmacológico , Inflamação/imunologia , Interleucina-1/imunologia , Animais , Caspase 1/metabolismo , Células Dendríticas/imunologia , Humanos , Interleucina-1/genética , Interleucina-1/uso terapêutico , Camundongos , Camundongos Transgênicos , Receptores de Interleucina-1/imunologia , Transdução de Sinais , Receptores Toll-Like/imunologiaRESUMO
IL-1 family member IL-37 limits innate inflammation in models of colitis and LPS-induced shock, but a role in adaptive immunity remains unknown. Here, we studied mice expressing human IL-37b isoform (IL-37tg) subjected to skin contact hypersensitivity (CHS) to dinitrofluorobenzene. CHS challenge to the hapten was significantly decreased in IL-37tg mice compared with wild-type (WT) mice (-61%; P < 0.001 at 48 h). Skin dendritic cells (DCs) were present and migrated to lymph nodes after antigen uptake in IL-37tg mice. When hapten-sensitized DCs were adoptively transferred to WT mice, antigen challenge was greatly impaired in mice receiving DCs from IL-37tg mice compared with those receiving DCs from WT mice (-60%; P < 0.01 at 48 h). In DCs isolated from IL-37tg mice, LPS-induced increase of MHC II and costimulatory molecule CD40 was reduced by 51 and 31%, respectively. In these DCs, release of IL-1ß, IL-6, and IL-12 was reduced whereas IL-10 secretion increased (37%). Consistent with these findings, DCs from IL-37tg mice exhibited a lower ability to stimulate syngeneic and allogeneic naive T cells as well as antigen-specific T cells and displayed enhanced induction of T regulatory (Treg) cells (86%; P < 0.001) in vitro. Histological analysis of CHS skin in mice receiving hapten-sensitized DCs from IL-37tg mice revealed a marked reduction in CD8(+) T cells (-74%) but an increase in Treg cells (2.6-fold). Together, these findings reveal that DCs expressing IL-37 are tolerogenic, thereby impairing activation of effector T-cell responses and inducing Treg cells. IL-37 thus emerges as an inhibitor of adaptive immunity.
Assuntos
Imunidade Adaptativa , Células Dendríticas/citologia , Interleucina-1/metabolismo , Animais , Linfócitos T CD8-Positivos/citologia , Movimento Celular , Quimiotaxia , Citocinas/metabolismo , Dermatite de Contato/imunologia , Dinitrofluorbenzeno/química , Citometria de Fluxo , Haptenos/química , Humanos , Imunidade Inata , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fagocitose , Pele/metabolismo , Linfócitos T Reguladores/citologiaRESUMO
IL-37 is a fundamental inhibitor of innate immunity. Human IL-37 has a caspase-1 cleavage site and translocates to the nucleus upon LPS stimulation. Here, we investigated whether caspase-1 processing affects IL-37-mediated suppression of LPS-induced cytokines and the release from cells by analyzing a caspase-1 cleavage site mutant IL-37 (IL-37D20A). Nuclear translocation of IL-37D20A is significantly impaired compared with WT IL-37 in transfected cells. LPS-induced IL-6 was decreased in cells expressing WT IL-37 but not IL-37D20A. The function of IL-37 in transfected bone marrow-derived macrophages is nucleotide-binding oligomerization domain-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome-dependent, because IL-37 transfection in apoptosis-associated speck-like protein containing a carboxyl-terminal caspase recruitment domain- and NLRP3-deficient cells does not reduce levels of IL-6 and IL-1ß upon LPS stimulation. IL-37-expressing macrophages release both precursor and mature IL-37, but only the externalization of mature IL-37 was dependent on ATP. Precursor and mature IL-37 was also secreted from human dendritic cells and peripheral blood mononuclear cells. To determine whether IL-37 is active in the extracellular compartment, we pretreated IL-37 transgenic mice with IL-37-neutralizing antibodies before LPS challenge. In IL-37-expressing mice, neutralizing IL-37 antibodies reversed the suppression of LPS-induced serum IL-6. In contrast, the addition of neutralizing antibody did not reverse suppression of LPS-induced IL-6 in mouse macrophages transfected with IL-37. Although caspase-1 is required for nuclear translocation of intracellular IL-37 and for secretion of mature IL-37, the release of the IL-37 precursor is independent of caspase-1 activation. IL-37 now emerges as a dual-function cytokine with intra- and extracellular properties for suppressing innate inflammation.
Assuntos
Anticorpos Neutralizantes/imunologia , Caspase 1/metabolismo , Núcleo Celular/metabolismo , Imunidade Inata/imunologia , Interleucina-1/metabolismo , Transporte Ativo do Núcleo Celular/imunologia , Animais , Western Blotting , Caspase 1/genética , Linhagem Celular , Escherichia coli , Imunofluorescência , Humanos , Interleucina-6/sangue , Lipopolissacarídeos , Camundongos , Camundongos Transgênicos , Microscopia Confocal , Mutagênese Sítio-DirigidaRESUMO
Bronchopulmonary dysplasia (BPD) is a chronic disease of extreme prematurity that has serious long-term consequences including increased asthma risk. We earlier identified IL-1 receptor antagonist (IL-1Ra) as a potent inhibitor of murine BPD induced by combining perinatal inflammation (intraperitoneal LPS to pregnant dams) and exposure of pups to hyperoxia (fraction of inspired oxygen = 0.65). In this study, we determined whether airway remodeling and hyperresponsiveness similar to asthma are evident in this model, and whether IL-1Ra is protective. During 28-day exposure to air or hyperoxia, pups received vehicle or 10 mg/kg IL-1Ra by daily subcutaneous injection. Lungs were then prepared for histology and morphometry of alveoli and airways, or for real-time PCR, or inflated with agarose to prepare precision-cut lung slices to visualize ex vivo intrapulmonary airway contraction and relaxation by phase-contrast microscopy. In pups reared under normoxic conditions, IL-1Ra treatment did not affect alveolar or airway structure or airway responses. Pups reared in hyperoxia developed a severe BPD-like lung disease, with fewer, larger alveoli, increased subepithelial collagen, and increased expression of α-smooth muscle actin and cyclin D1. After hyperoxia, methacholine elicited contraction with similar potency but with an increased maximum reduction in lumen area (air, 44%; hyperoxia, 89%), whereas dilator responses to salbutamol were maintained. IL-1Ra treatment prevented hyperoxia-induced alveolar disruption and airway fibrosis but, surprisingly, not the increase in methacholine-induced airway contraction. The current study is the first to demonstrate ex vivo airway hyperreactivity caused by systemic maternal inflammation and postnatal hyperoxia, and it reveals further preclinical mechanistic insights into IL-1Ra as a treatment targeting key pathophysiological features of BPD.
Assuntos
Remodelação das Vias Aéreas , Hiper-Reatividade Brônquica/complicações , Hiper-Reatividade Brônquica/metabolismo , Displasia Broncopulmonar/complicações , Displasia Broncopulmonar/metabolismo , Proteína Antagonista do Receptor de Interleucina 1/metabolismo , Remodelação das Vias Aéreas/efeitos dos fármacos , Albuterol/farmacologia , Animais , Hiper-Reatividade Brônquica/patologia , Hiper-Reatividade Brônquica/fisiopatologia , Displasia Broncopulmonar/patologia , Displasia Broncopulmonar/fisiopatologia , Modelos Animais de Doenças , Feminino , Hiperóxia/complicações , Hiperóxia/metabolismo , Hiperóxia/patologia , Hiperóxia/fisiopatologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Pulmão/fisiopatologia , Camundongos Endogâmicos C57BL , Contração Muscular/efeitos dos fármacos , Relaxamento Muscular/efeitos dos fármacos , Gravidez , Alvéolos Pulmonares/patologiaRESUMO
Bronchopulmonary dysplasia (BPD) is often complicated by pulmonary hypertension (PH). We investigated three biomarkers potentially suitable as screening markers for extremely preterm infants at risk of BPD-associated PH. In this prospective observational cohort study conducted in a tertiary neonatal intensive care unit, 83 preterm infants with BPD born <28-wk gestation and still inpatients at 36-wk corrected age received an echocardiogram and blood tests of B-type natriuretic peptide (BNP), troponin I, and YKL-40. Infants were analyzed according to echocardiographic evidence of tricuspid regurgitation (TR). Thirty infants had evidence of TR on echocardiogram at 36-wk corrected age. Infants with or without TR had similar baseline demographics: mean ± SD gestational age 261 ± 12 vs. 261 ± 11 wk and birth weight 830 ± 206 vs. 815 ± 187 g, respectively. There was no difference in duration of respiratory support. The right ventricular systolic pressure of infants with evidence of TR was 40 ± 16 mmHg. BNP was the only biomarker that proved to be significantly higher in infants with evidence of TR: median (interquartile range) serum level 54.5 (35-105) vs. 41.5 (30-59) pg/ml, P = 0.043. Subgroup analysis of infants with severe BPD requiring discharge on home oxygen or BPD-related mortality revealed similar results. There was no difference between groups for troponin I and YKL-40. In conclusion, increased serum levels of BNP were associated with evidence of TR at 36-wk corrected gestational age in extremely preterm infants, suggesting a potential role as a screening biomarker for BPD-associated PH.
Assuntos
Displasia Broncopulmonar/sangue , Proteína 1 Semelhante à Quitinase-3/sangue , Hipertensão Pulmonar/sangue , Lactente Extremamente Prematuro/sangue , Peptídeo Natriurético Encefálico/sangue , Troponina I/sangue , Biomarcadores/sangue , Displasia Broncopulmonar/complicações , Demografia , Feminino , Humanos , Hipertensão Pulmonar/complicações , Masculino , Ventilação Pulmonar , Fatores de RiscoRESUMO
Necrotising enterocolitis (NEC) is an uncommon, but devastating intestinal inflammatory disease that predominantly affects preterm infants. NEC is sometimes dubbed the spectre of neonatal intensive care units, as its onset is insidiously non-specific, and once the disease manifests, the damage inflicted on the baby's intestine is already disastrous. Subsequent sepsis and multi-organ failure entail a mortality of up to 65%. Development of effective treatments for NEC has stagnated, largely because of our lack of understanding of NEC pathogenesis. It is clear, however, that NEC is driven by a profoundly dysregulated immune system. NEC is associated with local increases in pro-inflammatory mediators, e.g. Toll-like receptor (TLR) 4, nuclear factor-κB, tumour necrosis factor, platelet-activating factor (PAF), interleukin (IL)-18, interferon-gamma, IL-6, IL-8 and IL-1ß. Deficiencies in counter-regulatory mechanisms, including IL-1 receptor antagonist (IL-1Ra), TLR9, PAF-acetylhydrolase, transforming growth factor beta (TGF-ß)1&2, IL-10 and regulatory T cells likely facilitate a pro-inflammatory milieu in the NEC-afflicted intestine. There is insufficient evidence to conclude a predominance of an adaptive Th1-, Th2- or Th17-response in the disease. Our understanding of the accompanying regulation of systemic immunity remains poor; however, IL-1Ra, IL-6, IL-8 and TGF-ß1 show promise as biomarkers. Here, we chart the emerging immunological landscape that underpins NEC by reviewing the involvement and potential clinical implications of innate and adaptive immune mediators and their regulation in NEC.
Assuntos
Suscetibilidade a Doenças/imunologia , Enterocolite Necrosante/etiologia , Enterocolite Necrosante/metabolismo , Fatores Etários , Animais , Biomarcadores , Ensaios Clínicos como Assunto , Modelos Animais de Doenças , Progressão da Doença , Suscetibilidade a Doenças/metabolismo , Enterocolite Necrosante/diagnóstico , Enterocolite Necrosante/epidemiologia , Humanos , Sistema Imunitário/citologia , Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , Imunidade , Fatores Imunológicos/metabolismo , Avaliação de Resultados da Assistência ao Paciente , Fenótipo , Receptores Imunológicos/metabolismo , Receptores de Reconhecimento de Padrão/metabolismo , Fatores de Risco , Índice de Gravidade de Doença , Transdução de SinaisRESUMO
IL-32 is a multifaceted cytokine with a role in infections, autoimmune diseases, and cancer, and it exerts diverse functions, including aggravation of inflammation and inhibition of virus propagation. We previously identified IL-32 as a critical regulator of endothelial cell (EC) functions, and we now reveal that IL-32 also possesses angiogenic properties. The hyperproliferative ECs of human pulmonary arterial hypertension and glioblastoma multiforme exhibited a markedly increased abundance of IL-32, and, significantly, the cytokine colocalized with integrin αVß3. Vascular endothelial growth factor (VEGF) receptor blockade, which resulted in EC hyperproliferation, increased IL-32 three-fold. Small interfering RNA-mediated silencing of IL-32 negated the 58% proliferation of ECs that occurred within 24 h in scrambled-transfected controls. Reduction of IL-32 neither affected apoptosis (insignificant changes in Bak-1, Bcl-2, Bcl-xL, lactate dehydrogenase, annexin V, and propidium iodide) nor VEGF or TGF-ß levels, but siIL-32-transfected adult and neonatal ECs produced up to 61% less NO, IL-8, and matrix metalloproteinase-9, and up to 3-fold more activin A and endostatin. In coculture-based angiogenesis assays, IL-32γ dose-dependently increased tube formation up to 3-fold; an αVß3 inhibitor prevented this activity and reduced IL-32γ-induced IL-8 by 85%. In matrigel plugs loaded with IL-32γ, VEGF, or vehicle and injected into live mice, we observed the anticipated VEGF-induced increase in neocapillarization (8-fold versus vehicle), but unexpectedly, IL-32γ was equally angiogenic. A second signal such as IFN-γ was required to render cells responsive to exogenous IL-32γ; importantly, this was confirmed using a completely synthetic preparation of IL-32γ. In summary, we add angiogenic properties that are mediated by integrin αVß3 but VEGF-independent to the portfolio of IL-32, implicating a role for this versatile cytokine in pulmonary arterial hypertension and neoplastic diseases.
Assuntos
Interleucinas/metabolismo , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Ativinas/metabolismo , Animais , Apoptose/fisiologia , Células Cultivadas , Endostatinas/metabolismo , Hipertensão Pulmonar Primária Familiar , Glioblastoma/embriologia , Glioblastoma/patologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Hipertensão Pulmonar/metabolismo , Hipertensão Pulmonar/patologia , Integrina alfaVbeta3/metabolismo , Interferon gama/metabolismo , Interleucina-8/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Camundongos , Óxidos de Nitrogênio/metabolismo , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptores de Fatores de Crescimento do Endotélio Vascular/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Bronchopulmonary dysplasia (BPD) is a common lung disease of premature infants, with devastating short- and long-term consequences. The pathogenesis of BPD is multifactorial, but all triggers cause pulmonary inflammation. No therapy exists; therefore, we investigated whether the anti-inflammatory interleukin-1 receptor antagonist (IL-1Ra) prevents murine BPD. We precipitated BPD by perinatal inflammation (lipopolysaccharide injection to pregnant dams) and rearing pups in hyperoxia (65% or 85% O2). Pups were treated daily with IL-1Ra or vehicle for up to 28 d. Vehicle-injected animals in both levels of hyperoxia developed a severe BPD-like lung disease (alveolar number and gas exchange area decreased by up to 60%, alveolar size increased up to fourfold). IL-1Ra prevented this structural disintegration at 65%, but not 85% O2. Hyperoxia depleted pulmonary immune cells by 67%; however, extant macrophages and dendritic cells were hyperactivated, with CD11b and GR1 (Ly6G/C) highly expressed. IL-1Ra partially rescued the immune cell population in hyperoxia (doubling the viable cells), reduced the percentage that were activated by up to 63%, and abolished the unexpected persistence of IL-1α and IL-1ß on day 28 in hyperoxia/vehicle-treated lungs. On day 3, perinatal inflammation and hyperoxia each triggered a distinct pulmonary immune response, with some proinflammatory mediators increasing up to 20-fold and some amenable to partial or complete reversal with IL-1Ra. In summary, our analysis reveals a pivotal role for IL-1α/ß in murine BPD and an involvement for MIP (macrophage inflammatory protein)-1α and TREM (triggering receptor expressed on myeloid cells)-1. Because it effectively shields newborn mice from BPD, IL-1Ra emerges as a promising treatment for a currently irremediable disease that may potentially brighten the prognosis of the tiny preterm patients.
Assuntos
Displasia Broncopulmonar/prevenção & controle , Hiperóxia/complicações , Inflamação/complicações , Proteína Antagonista do Receptor de Interleucina 1/fisiologia , Animais , Displasia Broncopulmonar/etiologia , Modelos Animais de Doenças , Feminino , Humanos , Recém-Nascido , Lipopolissacarídeos/farmacologia , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Camundongos , Camundongos Endogâmicos C57BL , GravidezRESUMO
AIM: Dopamine is used as an inotropic medication in preterm infants. The preterm human blood brain barrier (BBB) is permeable to intravascular dopamine, and the impact of exogenous dopamine on the preterm brain remains unknown. The preterm lamb model may be suitable for studying the cerebral impact of dopamine therapy whether its BBB permeability is similar to preterm human infants. We aimed to examine BBB permeability to exogenous dopamine in the preterm lamb, by measuring dopamine levels in the cerebrospinal fluid (CSF). METHODS: Nine preterm foetal lambs (125-130 days, term = 147 days) were given either dopamine at 10 µg/kg/min (dopamine, n = 4) or saline (control, n = 5). CSF, and plasma samples were taken for dopamine assay. RESULTS: The median (range) baseline CSF dopamine level for the combined control and dopamine groups (n = 9) was 0.10(0.03-0.16) ng/mL, and baseline plasma dopamine was 0.30(0.13-0.84) ng/mL. The dopamine lambs showed increase in CSF dopamine to 3.91(1.87-11.35) ng/mL with plasma dopamine increased to 14.2 (9.1-57.9) ng/mL. No change was found in the control lambs. CONCLUSION: In the preterm lamb, the BBB permeability and pharmacokinetics to dopamine infusion are similar to findings in the preterm human infant, supporting applicability of the preterm lamb model for studying effects of dopamine infusion in the preterm human brain.
Assuntos
Barreira Hematoencefálica , Dopaminérgicos/farmacocinética , Dopamina/farmacocinética , Animais , Animais Recém-Nascidos , Dopamina/líquido cefalorraquidiano , Dopaminérgicos/administração & dosagem , Infusões Intravenosas , OvinosRESUMO
IL-37, a newly described member of the IL-1 family, functions as a fundamental inhibitor of innate inflammation and immunity. In the present study, we examined a role for IL-37 during experimental colitis. A transgenic mouse strain was generated to express human IL-37 (hIL-37tg), and these mice were subjected to dextran sulfate sodium (DSS)-induced colitis. Despite the presence of a CMV promoter to drive expression of IL-37, mRNA transcripts were not present in colons at the resting state. Expression was observed only upon disruption of the epithelial barrier, with a six- to sevenfold increase (P = 0.02) on days 3 and 5 after continuous exposure to DSS. During the development of colitis, clinical disease scores were reduced by 50% (P < 0.001), and histological indices of colitis were one-third less in hIL-37tg mice compared with WT counterparts (P < 0.001). Reduced inflammation was associated with decreased leukocyte recruitment into the colonic lamina propria. In addition, release of IL-1ß and TNFα from ex vivo colonic explant tissue was decreased 5- and 13-fold, respectively, compared with WT (P ≤ 0.005), whereas IL-10 was increased sixfold (P < 0.001). However, IL-10 was not required for the anti-inflammatory effects of IL-37 because IL-10-receptor antibody blockade did not reverse IL-37-mediated protection. Mechanistically, IL-37 originating from hematopoietic cells was sufficient to exert anti-inflammatory effects because WT mice reconstituted with hIL-37tg bone marrow were protected from colitis. Thus, IL-37 emerges as key modulator of intestinal inflammation.