RESUMO
BACKGROUND: Gut microbiota-derived short-chain fatty-acid (SFCA) acetate protects mice against RSV A2 strain infection by increasing interferon-ß production and expression of interferon-stimulated genes (ISGs). However, the role of SFCA in RSV infection using strains isolated from patients is unknown. METHODS: We first used RSV clinical strains isolated from infants hospitalized with RSV bronchiolitis to investigate the effects of in vitro SCFA-acetate treatment of human pulmonary epithelial cells. We next examined whether SCFA-acetate treatment is beneficial in a mouse model of RSV infection using clinical isolates. We sought to investigate the relationship of gut microbiota and fecal acetate with disease severity among infants hospitalized with RSV bronchiolitis, and whether treating their respiratory epithelial cells with SCFA-acetate ex-vivo impacts viral load and ISG expression. We further treated epithelial cells from SARS-CoV-2 infected patients with SCFA-acetate. FINDINGS: In vitro pre-treatment of A549 cells with SCFA-acetate reduced RSV infection with clinical isolates and increased the expression of RIG-I and ISG15. Animals treated with SCFA-acetate intranasally recovered significantly faster, with reduction in the RSV clinical isolates viral load, and increased lung expression of IFNB1 and the RIG-I. Experiments in RIG-I knockout A549 cells demonstrated that the protection relies on RIG-I presence. Gut microbial profile was associated with bronchiolitis severity and with acetate in stool. Increased SCFA-acetate levels were associated with increasing oxygen saturation at admission, and shorter duration of fever. Ex-vivo treatment of patients' respiratory cells with SCFA-acetate reduced RSV load and increased expression of ISGs OAS1 and ISG15, and virus recognition receptors MAVS and RIG-I, but not IFNB1. These SCFA-acetate effects were not found on cells from SARS-CoV-2 infected patients. INTERPRETATION: SCFA-acetate reduces the severity of RSV infection and RSV viral load through modulation of RIG-I expression. FUNDING: FAPERGS (FAPERGS/MS/CNPq/SESRS no. 03/2017 - PPSUS 17/2551-0001380-8 and COVID-19 20/2551-0000258-6); CNPq 312504/2017-9; CAPES) - Finance Code 001.
Assuntos
Bronquiolite , COVID-19 , Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano , Acetatos/metabolismo , Acetatos/farmacologia , Animais , Antivirais/metabolismo , Antivirais/farmacologia , Antivirais/uso terapêutico , Bronquiolite/tratamento farmacológico , Bronquiolite/metabolismo , Ácidos Graxos Voláteis/metabolismo , Humanos , Lactente , Pulmão/metabolismo , Camundongos , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Infecções por Vírus Respiratório Sincicial/genética , Vírus Sincicial Respiratório Humano/fisiologia , SARS-CoV-2RESUMO
Respiratory syncytial virus (RSV) is a major cause of diseases of the respiratory tract in young children and babies, being mainly associated with bronchiolitis. RSV infection occurs primarily in pulmonary epithelial cells and, once infection is established, an immune response is triggered and neutrophils are recruited. In this study, we investigated the mechanisms underlying NET production induced by RSV. We show that RSV induced the classical ROS-dependent NETosis in human neutrophils and that RSV was trapped in DNA lattices coated with NE and MPO. NETosis induction by RSV was dependent on signaling by PI3K/AKT, ERK and p38 MAPK and required histone citrullination by PAD-4. In addition, RIPK1, RIPK3 and MLKL were essential to RSV-induced NETosis. MLKL was also necessary to neutrophil necrosis triggered by the virus, likely promoting membrane-disrupting pores, leading to neutrophil lysis and NET extrusion. Finally, we found that RSV infection of alveolar epithelial cells or lung fibroblasts triggers NET-DNA release by neutrophils, indicating that neutrophils can identify RSV-infected cells and respond to them by releasing NETs. The identification of the mechanisms responsible to mediate RSV-induced NETosis may prove valuable to the design of new therapeutic approaches to treat the inflammatory consequences of RSV bronchiolitis in young children.
Assuntos
Armadilhas Extracelulares/metabolismo , Necrose/metabolismo , Neutrófilos/metabolismo , Desiminases de Arginina em Proteínas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Infecções por Vírus Respiratório Sincicial/metabolismo , Vírus Sincicial Respiratório Humano/patogenicidade , Adulto , Células Epiteliais Alveolares/metabolismo , Células Epiteliais Alveolares/virologia , Animais , Apoptose/fisiologia , Bronquiolite/metabolismo , Bronquiolite/virologia , Linhagem Celular , Chlorocebus aethiops , Armadilhas Extracelulares/virologia , Feminino , Humanos , Pulmão/metabolismo , Pulmão/virologia , Masculino , Necrose/virologia , Neutrófilos/virologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteína-Arginina Desiminase do Tipo 4 , Infecções por Vírus Respiratório Sincicial/virologia , Transdução de Sinais/fisiologia , Células VeroRESUMO
OBJECTIVE: To identify morning salivary cortisol reference values in infancy and at 2 years of age and to investigate the influence of age, sex and acute bronchiolitis. STUDY DESIGN: In this South-East Norwegian cohort study, 308 children hospitalized with moderate to severe acute bronchiolitis in infancy in 2010-2011 were compared with 223 healthy controls included in 2012 by measuring morning salivary cortisol levels at inclusion and at 2 years of age. Samples were collected shortly after awakening after 6 am. The influences of age, sex, and acute bronchiolitis were assessed by regression analysis. RESULTS: In infancy, cortisol values were higher in acute bronchiolitis, with an age- and sex-adjusted weighted mean group difference of 13.9 nmol/L (95% CI 8.1-19.7; P < .0001). The median level in reference group was 23.7 nmol/L (95% CI 9.7-119.6). At 2 years of age, sex but not inclusion groups differed, with significantly higher values in girls. The weighted mean of all boys' cortisol levels was 32.4 nmol/L, (95% CI 30.5-34.3), and all girls' levels were 36.9 nmol/L (95% CI 34.7-39.2; P < .003). CONCLUSIONS: Salivary cortisol levels were higher at 2 years of age than in infancy in the reference group, were higher in girls than in boys at 2 years of age, and were higher in infants at the time of acute bronchiolitis than in healthy infants. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00817466.
Assuntos
Bronquiolite , Hidrocortisona/análise , Saliva/química , Doença Aguda , Fatores Etários , Bronquiolite/metabolismo , Pré-Escolar , Ritmo Circadiano , Estudos de Coortes , Feminino , Humanos , Hidrocortisona/biossíntese , Lactente , Masculino , Valores de Referência , Índice de Gravidade de Doença , Fatores SexuaisRESUMO
Respiratory Syncytial Virus (RSV) is the first cause of hospitalization due to bronchiolitis in infants. RSV bronchiolitis has been linked to asthma and recurrent wheezing, however the mechanisms behind this association have not been elucidated. Here, we evaluated the cytokine and chemokine profiles in the airways in infants with RSV bronchiolitis. Nasopharyngeal Aspirates (NPA) and Bronchoalveolar Lavage Fluids (BALF) from infants hospitalized due to RSV bronchiolitis and healthy controls were analyzed for cytokine and chemokine production. We observed elevated levels of Th2 cytokines (IL-3, IL-4, IL-10 and IL-13), pro-inflammatory cytokines and chemokines (IL-1ß, IL-6, TNF-ß, MCP-1/CCL2, MIP-1α/CCL3 and IL-8/CXCL8) in BALF from infants with RSV bronchiolitis, as compared to controls. We found a direct correlation of IL-3 and IL-12p40 levels with the development of recurrent wheezing later in life. These results suggest that IL-3 and IL-12p40 could be considered as molecular predictors for recurrent wheezing due to RSV infection.
Assuntos
Brônquios/metabolismo , Bronquiolite/metabolismo , Interleucina-12/metabolismo , Interleucina-3/metabolismo , Sons Respiratórios , Infecções por Vírus Respiratório Sincicial/metabolismo , Líquido da Lavagem Broncoalveolar , Estudos de Casos e Controles , Feminino , Humanos , Lactente , Interleucina-12/genética , Interleucina-3/genética , Masculino , RNA Mensageiro/genética , RecidivaRESUMO
OBJETIVO: O estresse oxidativo demonstrou contribuir para a patogênese de doenças pulmonares inflamatórias agudas e crônicas. Nosso objetivo foi avaliar o estado oxidante/antioxidante de crianças com bronquiolite aguda por meio de mensuração da capacidade antioxidante total do plasma, estado oxidante total e índice de estresse oxidativo. MÉTODOS: As crianças com bronquiolite aguda encaminhadas para o Departamento de Emergência Pediátrica do hospital universitário entre janeiro e abril 2012 foram comparadas a controles saudáveis de mesma idade. Os pacientes com bronquiolite aguda tiveram essa doença classificada como leve e moderada. O estado oxidante e antioxidante foi avaliado pela mensuração da capacidade antioxidante total do plasma, estado oxidante total e índice de estresse oxidativo. RESULTADOS: Foram incluídas 31 crianças com bronquiolite aguda com idade de três meses a dois anos e 37 crianças saudáveis. O estado oxidante total (EOT) foi maior em pacientes com bronquiolite aguda do que no grupo de controle (5,16±1,99 µmol H2O2 em comparação a 3,78±1,78 µmol H2O2 [p = 0,004]). A capacidade antioxidante total (CAT) foi significativamente menor em crianças com bronquiolite que no grupo de controle (2,51±0,37 µmol Trolox equivalente/L em comparação a 2,75±0,39 µmol Trolox Eqv/L) (p = 0,013). Os pacientes com bronquiolite moderada apresentaram níveis de EOT mais elevados que os com bronquiolite leve e os do grupo de controle (p = 0,03, p < 0,001). Os pacientes com bronquiolite moderada apresentaram níveis de IEO mais elevados que os do grupo de controle (p = 0,015). O nível de saturação de oxigênio de pacientes com bronquiolite foi inversamente correlacionado ao nível de EOT (r = -0,476, p < 0,05). CONCLUSÃO: O equilíbrio entre os sistemas oxidante e antioxidante é interrompido em crianças com bronquiolite moderada, indicando que o fator de estresse poderá ter um papel na patogênese da doença.
OBJECTIVE: Oxidative stress has been shown to contribute to the pathogenesis of acute and chronic lung inflammatory diseases. This article aimed to evaluate the oxidant/antioxidant status of children with acute bronchiolitis through the measurement of plasma total antioxidant capacity, total oxidant status, and oxidative stress index. METHODS: Children with acute bronchiolitis admitted to the pediatric emergency department of a university hospital between January and April of 2012 were compared with agematched healthy controls. Patients with acute bronchiolitis were classified as mild and moderate bronchiolitis. Oxidative and antioxidative status were assessed by measurement of plasma total antioxidant capacity, total oxidant status, and oxidative stress index. RESULTS: Thirty-one children with acute bronchiolitis aged between 3 months and 2 years, and 39 healthy children were included. Total oxidative status (TOS) was higher in patients with acute bronchiolitis than the control group (5.16±1.99 µmol H2O2 versus 3.78±1.78 µmol H2O2 [p = 0.004]). Total antioxidant capacity (TAC) was lower in children with bronchiolitis than the control group (2.51±0.37 µmol Trolox eqv/L versus 2.75±0.39 µmol Trolox eqv/L [p = 0.013]). Patients with moderate bronchiolitis presented higher TOS levels than those with mild bronchiolitis and the control group (p = 0.03, p < 0.001, respectively). Patients with moderate bronchiolitis had higher oxidative stress index levels than the control group (p = 0.015). Oxygen saturation level of bronchiolitis patients was inversely correlated with TOS (r = -0.476, p < 0.05). CONCLUSION: The balance between oxidant and antioxidant systems is disrupted in children with moderate bronchiolitis, which indicates that this stress factor may have a role in the pathogenesis of the disease.
Assuntos
Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Antioxidantes/análise , Bronquiolite/metabolismo , Oxidantes/sangue , Estresse Oxidativo/fisiologia , Antioxidantes/fisiologia , Biomarcadores/sangue , Bronquiolite/etiologia , Estudos de Casos e ControlesRESUMO
OBJECTIVE: Oxidative stress has been shown to contribute to the pathogenesis of acute and chronic lung inflammatory diseases. This article aimed to evaluate the oxidant/antioxidant status of children with acute bronchiolitis through the measurement of plasma total antioxidant capacity, total oxidant status, and oxidative stress index. METHODS: Children with acute bronchiolitis admitted to the pediatric emergency department of a university hospital between January and April of 2012 were compared with age-matched healthy controls. Patients with acute bronchiolitis were classified as mild and moderate bronchiolitis. Oxidative and antioxidative status were assessed by measurement of plasma total antioxidant capacity, total oxidant status, and oxidative stress index. RESULTS: Thirty-one children with acute bronchiolitis aged between 3 months and 2 years, and 39 healthy children were included. Total oxidative status (TOS) was higher in patients with acute bronchiolitis than the control group (5.16±1.99 µmol H2O2 versus 3.78±1.78 µmol H2O2 [p=0.004]). Total antioxidant capacity (TAC) was lower in children with bronchiolitis than the control group (2.51±0.37 µmol Trolox eqv/L versus 2.75±0.39 µmol Trolox eqv/L [p=0.013]). Patients with moderate bronchiolitis presented higher TOS levels than those with mild bronchiolitis and the control group (p=0.03, p<0.001, respectively). Patients with moderate bronchiolitis had higher oxidative stress index levels than the control group (p=0.015). Oxygen saturation level of bronchiolitis patients was inversely correlated with TOS (r=-0.476, p<0.05). CONCLUSION: The balance between oxidant and antioxidant systems is disrupted in children with moderate bronchiolitis, which indicates that this stress factor may have a role in the pathogenesis of the disease.
Assuntos
Antioxidantes/análise , Bronquiolite/metabolismo , Oxidantes/sangue , Estresse Oxidativo/fisiologia , Antioxidantes/fisiologia , Biomarcadores/sangue , Bronquiolite/etiologia , Estudos de Casos e Controles , Pré-Escolar , Feminino , Humanos , Lactente , MasculinoRESUMO
Eosinophil cationic protein (ECP), a cytotoxic protein contained in the granules of eosinophils, has been suggested as having an important role in the pathogenesis of asthma. To determine whether ECP plays a similar role in bronchiolitis, we tested samples of nasopharyngeal secretions, obtained from a group of 47 children with various forms of illness related to respiratory syncytial virus (RSV) and from 26 children with non-RSV upper respiratory tract illness or bacterial pneumonia, for the presence of ECP by means of a double-antibody radioimmunoassay. Concentrations of ECP in children with RSV bronchiolitis were significantly higher (166.8 ng/ml) than the mean concentration of ECP in both groups of children with RSV upper respiratory tract illness (43.5 ng/ml, p less than 0.002) and RSV lower respiratory tract disease without wheezing (29.1 ng/ml; p less than 0.0002). Children with non-RSV upper respiratory tract illness or bacterial pneumonia had levels of ECP in nasopharyngeal secretions similar to those of children with RSV upper respiratory tract illness or RSV pneumonia. High ECP levels in nasopharyngeal secretions (greater than 50 ng/ml) were predictive of the development of bronchiolitis at the time of RSV infection (p less than 0.001), and the individual ECP levels correlated with severity of the disease as determined by the initial PaO2 concentrations (p less than 0.05). These data suggest that eosinophil degranulation in the respiratory tract occurs during RSV bronchiolitis and may play a significant role in the development of virus-induced airway obstruction.