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Pulmonary irritants, such as cigarette smoke (CS) and sodium hypochlorite (NaClO), are associated to pulmonary diseases in cleaning workers. We examined whether their association affects lung mechanics and inflammation in Wistar rats. Exposure to these irritants alone induced alterations in the lung mechanics, inflammation, and remodeling. The CS increased airway cell infiltration, acid mucus production, MMP-12 expression, and alveolar enlargement. NaClO increased the number of eosinophils and macrophages in the bronchoalveolar lavage fluid, with cells expressing IL-13, MMP-12, MMP-9, TIMP-1, and iNOS in addition to increased IL-1ß and TNF-α levels. Co-exposure to both irritants increased epithelial and smooth muscle cell area, acid mucus production, and IL-13 expression in the airways, while it reduced the lung inflammation. In conclusion, the co-exposure of CS with NaClO reduced the pulmonary inflammation, but increased the acidity of mucus, which may protect lungs from more injury. A cross-resistance in people exposed to multiple lung irritants should also be considered.
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Fumar Cigarrillos , Lesión Pulmonar , Neumonía , Animales , Líquido del Lavado Bronquioalveolar , Humanos , Inflamación/inducido químicamente , Inflamación/metabolismo , Interleucina-13/metabolismo , Irritantes/metabolismo , Irritantes/farmacología , Pulmón/metabolismo , Lesión Pulmonar/inducido químicamente , Lesión Pulmonar/metabolismo , Metaloproteinasa 12 de la Matriz/metabolismo , Neumonía/metabolismo , Ratas , Ratas Wistar , Hipoclorito de Sodio/metabolismo , Hipoclorito de Sodio/farmacología , NicotianaRESUMEN
Autonomy is a process that enables us to understand and act on the environment and on ourselves. During adolescence, transformations result in the development of autonomy. Adolescents with Down syndrome (ADS) have perceptual-cognitive limitations and few opportunities to acquire autonomy. The development of autonomy in an occupational therapy group, with dyads of ADS and their main caregivers was analyzed. The evaluation of the materials produced in the therapeutic process pointed to four categories of analysis: self-perception, perception of the other, shared experience and change of attitude. The results show symbiotic relationships between the dyad, which hamper the individuation process and limit the opportunities to carry out activities independently. The therapeutic process based on Paulo Freire's pedagogy raised the level from an ingenuous to a critical awareness, resulting in changes in the attitudes of caregivers in relation to the identification of potential and acceptance of their own limitations and the ADS under care. This symbiosis complicates the individuation process and the access to experiences necessary for the development of autonomy. The therapeutic process can modify the attitudes of caregivers and foster continuity in development and autonomy.
A autonomia é um processo que nos capacita a compreender e agir sobre nós mesmos e sobre o ambiente. Na adolescência, transformações resultam no desenvolvimento da autonomia. Adolescentes com Síndrome de Down (ASD) têm limitações percepto-cognitivas e poucas oportunidades para aquisição de autonomia. Analisamos o desenvolvimento da autonomia em um grupo terapêutico de Terapia Ocupacional, com díades de ASD e seus principais cuidadores. A análise dos materiais documentais produzidos no processo terapêutico apontou quatro categorias de análise: autopercepção, percepção do outro, vivência compartilhada e mudança de atitude. Os resultados mostram relações simbióticas entre a díade, que dificultam o processo de individuação e limitam as oportunidades para realização das atividades de modo independente. O processo terapêutico baseado na pedagogia freiriana mobilizou de uma consciência ingênua para crítica, acarretando mudanças nas atitudes dos cuidadores em relação à identificação de potenciais e aceitação de limitações próprias e do ASD cuidado. Essa simbiose dificulta o processo de individuação e o acesso a experiências necessárias para o desenvolvimento de autonomia. O processo terapêutico pode modificar as atitudes dos cuidadores e propiciar continuidade do desenvolvimento e autonomia.
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Síndrome de Down , Adolescente , Cuidadores , HumanosRESUMEN
BACKGROUND: In self-regulated learning, learning is defined as metacognitively guided, intrinsically motivated and strategic. In the context of medical education, the development of self-regulated learning can be associated with better academic and clinical performance. Hence, this report focuses on demonstrating the association between metacognitive awareness and motivation to learn among medical students in the clinical sciences portion of their education (3rd and 4th years of the medical programme) and characterizing medical students' motivational factors. METHODS: We performed a cross-sectional study with a qualitative and quantitative approach involving medical students from the University of Sao Paulo (USP) in Brazil. We have selected validated self-report questionnaires for the evaluation of metacognition (the Schraw and Dennison Metacognitive Awareness Inventory - MAI) and motivation to learn (the Baranik, Barron and Finney Achievement Goals for a Work Domain - AGWD). MAI has two domains: knowledge about cognition and regulation of cognition. AGWD divides achievement goals into mastery approach, mastery avoidance, performance approach and performance avoidance goal orientations. We also performed a qualitative analysis based on an open-ended question: "What motivates me the most in medical training?" RESULTS: One hundred eighty-five students completed the questionnaires: 103 (55.67%) were men, 110 (59.45%) were in their fourth year of the medical programme, and 152 (82.16%) were up to 24 years old. Only the knowledge about cognition domain of MAI was significantly associated with motivation to learn. We found that higher scores on the knowledge about cognition domain of MAI was associated with the mastery approach goal orientation (p = 0.003, median 0.71, IQR 0.23) and that lower scores on this same domain was associated with a mastery avoidance goal orientation (p = 0.034, median 0.65, IQR 0.14). The open-ended question showed that altruism, personal satisfaction, financial feedback, personal and supportive networks and graduating were motivational factors. CONCLUSIONS: Metacognitive awareness and motivation to learn are closely related. This association may represent a potential target for the educational process, as deans and faculty can adopt strategies focused on promoting self-regulated learning concerning students' motivational factors. This could enhance academic outcomes and promote more enjoyable learning.
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Metacognición , Estudiantes de Medicina , Brasil , Estudios Transversales , Femenino , Objetivos , Humanos , Masculino , Motivación , Encuestas y CuestionariosRESUMEN
INTRODUCTION: Reduced expression of the vesicular acetylcholine transporter (VAChT) leads to changes in the distribution and shape of synaptic vesicles (SVs) at neuromuscular junctions (NMJs), suggesting vesicular acetylcholine (ACh) as a key component of synaptic structure and function. It is poorly understood how long-term changes in cholinergic transmission contribute to age- and disease-related degeneration in the motor system. METHODS: In this study we performed confocal imaging, electrophysiology, electron microscopy, and analyses of respiratory mechanics of the diaphragm NMJ components in 12-month-old wild-type (WT) and VAChTKDHOM mice. RESULTS: Diaphragms of NMJs of the VAChTKDHOM mice were similar to those in WT mice in number, colocalization, and fragmentation of pre-/postsynaptic components. However, they had increased spontaneous SV exocytosis, miniature endplate potential frequency, and diminished MEPP amplitude. No impairment in respiratory mechanics at rest was observed, probably due to the large neurotransmission safety factor of the diaphragm. DISCUSSION: The present findings help us to understand the consequences of reduced ACh release at the NMJs during aging.
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Envejecimiento/patología , Diafragma/ultraestructura , Síndromes Miasténicos Congénitos/patología , Unión Neuromuscular/ultraestructura , Vesículas Sinápticas/ultraestructura , Acetilcolina/metabolismo , Envejecimiento/metabolismo , Animales , Diafragma/metabolismo , Diafragma/fisiopatología , Modelos Animales de Enfermedad , Endocitosis , Potenciales Postsinápticos Excitadores/fisiología , Exocitosis , Técnicas de Silenciamiento del Gen , Ratones , Microscopía Confocal , Microscopía Electrónica de Transmisión , Placa Motora , Síndromes Miasténicos Congénitos/genética , Síndromes Miasténicos Congénitos/metabolismo , Síndromes Miasténicos Congénitos/fisiopatología , Unión Neuromuscular/metabolismo , Unión Neuromuscular/fisiopatología , Mecánica Respiratoria/fisiología , Transmisión Sináptica , Vesículas Sinápticas/metabolismo , Proteínas de Transporte Vesicular de Acetilcolina/genéticaRESUMEN
The benefits of moderate aerobic physical exercise for allergic asthma are well-known, particularly that of the anti-inflammatory effect that occurs by reducing Th2 responses and lung remodeling. However, the mechanisms of this immunoregulation are still under investigation. In this study, we investigated the possible immunoregulatory mechanisms of lung inflammation induced by moderate aerobic exercise in an experimental asthma model. BALB/c mice were distributed into Control, Exercise (EX), OVA, and OEX groups. OVA and OEX groups were sensitized with ovalbumin (OVA) on days 0, 14, 21, 28, and 42 and were challenged with OVA aerosol three times a week from days 21 to 51. The EX and OEX groups underwent moderate aerobic physical exercise from days 21 to 51 (5 d/w, 1 h/d). The mice were euthanized on day 52. We evaluated pulmonary cytokine production, serum immunoglobulin levels, and the inflammatory cell profile in lung and mediastinal lymph nodes. OVA mice showed increased expression of IL-4, IL-6, IL-10, and TGF-ß and decreased macrophage type 2 (M2) recruitment. Physical exercise did not affect the increased antibody production of IgG2a, IgG1, or IgE induced by OVA. Of note, physical exercise alone markedly increased production of anti-inflammatory cytokines such as IL-10 and TGF-ß. Physical exercise in OVA-mice also increased the recruitment of M2 in the lungs, as well as the influx and activation of regulatory T cells (Tregs) and CD4 and CD8 lymphocytes. In the draining lymph nodes, it was also observed that physical exercise increased the activation of CD4 T cells, regardless of the presence of OVA. Notably, physical exercise decreased common dendritic cells' (cDCs; pro-inflammatory) expression of co-stimulatory molecules such as CD80, CD86, and ICOSL in the draining lymph nodes, as well as increased ICOSL in plasmacytoid dendritic cells (pDCs; anti-inflammatory). Together, these findings show that physical exercise modulates pulmonary allergic inflammation by increasing Treg and M2 recruitment, as well as pDCs activation, which leads to an increase in anti-inflammatory cytokines and a decrease in pro-inflammatory cells and mediators.
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Asma/inmunología , Células Dendríticas/inmunología , Hipersensibilidad/inmunología , Macrófagos/inmunología , Condicionamiento Físico Animal , Linfocitos T Reguladores/inmunología , Animales , Modelos Animales de Enfermedad , Masculino , Ratones , Ratones Endogámicos BALB C , Neumonía/inmunologíaRESUMEN
Background. The epidemiologic association between pulmonary exposure to ambient particulate matter (PM) and acute lung damage is well known. However, the mechanism involved in the effects of repeated exposures of PM in the lung injury is poorly documented. This study tested the hypotheses that chronic nasal instillation of residual oil fly ash (ROFA) induced not only distal lung and airway inflammation but also remodeling. In addition, we evaluated the effects of inducible nitric oxide inhibition in these responses. For this purpose, airway and lung parenchyma were evaluated by quantitative analysis of collagen and elastic fibers, immunohistochemistry for macrophages, neutrophils, inducible nitric oxide synthase (iNOS), neuronal nitric oxide synthase (nNOS), and alveolar septa 8-iso prostaglandin F2α (8-iso-PGF-2α) detection. Anesthetized in vivo (airway resistance, elastance, H, G, and Raw) respiratory mechanics were also analyzed. C57BL6 mice received daily 60ul of ROFA (intranasal) for five (ROFA-5d) or fifteen days (ROFA-15d). Controls have received saline (SAL). Part of the animals has received 1400W (SAL+1400W and ROFA-15d+1400W), an iNOS inhibitor, for four days before the end of the protocol. A marked neutrophil and macrophage infiltration and an increase in the iNOS, nNOS, and 8-iso-PGF2 α expression was observed in peribronchiolar and alveolar wall both in ROFA-5d and in ROFA-15d groups. There was an increment of the collagen and elastic fibers in alveolar and airway walls in ROFA-15d group. The iNOS inhibition reduced all alterations induced by ROFA, except for the 8-iso-PGF2 α expression. In conclusion, repeated particulate matter exposures induce extracellular matrix remodeling of airway and alveolar walls, which could contribute to the pulmonary mechanical changes observed. The mechanism involved is, at least, dependent on the inducible nitric oxide activation.
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Remodelación de las Vías Aéreas (Respiratorias) , Iminas/farmacología , Pulmón/metabolismo , Óxido Nítrico Sintasa de Tipo II/antagonistas & inhibidores , Material Particulado , Animales , Colágeno/metabolismo , Dinoprost/metabolismo , Tejido Elástico/metabolismo , Macrófagos/metabolismo , Ratones Endogámicos C57BL , Modelos Animales , Neutrófilos/metabolismo , Óxido Nítrico Sintasa de Tipo I/metabolismoRESUMEN
INTRODUCTION: Proteinase inhibitors have been associated with anti-inflammatory and antioxidant activities and may represent a potential therapeutic treatment for asthma. PURPOSE: The aim of the present study was to evaluate the effects of Enterolobium contortisiliquum trypsin inhibitor (EcTI) on pulmonary mechanical function, eosinophilic recruitment, inflammatory cytokines, remodeling and oxidative stress in an experimental model of chronic allergic pulmonary inflammation. METHODS: BALB/c mice were divided into 4 groups: C (saline i.p and inhalations with saline), OVA (ovalbumin i.p and inhalations with ovalbumin); C+EC (saline i.p, inhalations with s aline and treatment with EcTI); OVA+EC (ovalbumin i.p, inhalations with ovalbumin and treatment with EcTI). On day 29, we performed the following tests: resistance (Rrs) and elastance (Ers) of the respiratory system; (b) quantify eosinophils, 8-ISO-PGF2α, collagen and elastic fiber volume fractions; (c) IFN-γ, IL-4, IL-5, IL-13, MMP-9, TIMP-1, TGF-ß, iNOS and p65-NFκB-positive cells in the airway and alveolar walls. RESULTS: In OVA+EC group, there was an attenuation of the Rrs and Ers, reduction of eosinophils, IL-4, IL-5, IL-13, IFN-γ, iNOS and p65-NFκB-positive cells compared to OVA group. The 8-ISO-PGF2α, elastic and collagen fibers volume fractions as well as the positive cells for MMP-9, TIMP-1 and TGF-ß positive cells were decreased in OVA+EC compared to the OVA group. CONCLUSION: EcTI attenuates bronchial hyperresponsiveness, inflammation, remodeling and oxidative stress activation in this experimental mouse model of asthma.
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Remodelación de las Vías Aéreas (Respiratorias)/efectos de los fármacos , Asma/patología , Extractos Vegetales/farmacología , Inhibidores de Proteasas/farmacología , Animales , Modelos Animales de Enfermedad , Fabaceae , Inflamación/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Proteínas de Plantas/farmacología , Hipersensibilidad Respiratoria/patologíaRESUMEN
A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.
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BACKGROUND: The higher level of participation by women in medicine may impact this profession's evolution due to gender differences perceived during medical school, after graduation and during residency. Gender differences regarding quality of life are associated with higher states of anxiety and depression among female physicians. We aimed to assess gender differences in the perception of quality of life with quantitative methods and to understand further, from the female residents´ point of view, the reasons that may influence the perception of quality of life using qualitative method. Resilience, empathy and daytime sleepiness were also scored. METHODS: We performed a cross-sectional study with first-year internal medicine residents to evaluate self-reported quality of life factors specific to medical residents (VERAS-Q), including empathy (Jefferson Scale of Empathy), resilience (Wagnild and Young Brief Resilience Scale) and daytime sleepiness (Epworth Scale). We explored, from the female residents´ view which factors may influence the perception of quality of life using a focus group method. RESULTS: In our study, one hundred and nine residents completed the survey: 31 (28.4%) were female and 78 (71.6%) were male. Female residents exhibited significantly lower scores than those of male residents for quality of life in the domains of time management (30.3, females vs 41.1, males; p < 0.001), psychology (48.1, females vs 56.7, males; p < 0.01) and physical health (42.8, females vs 53.6, males; p < 0.05). Female residents also scored higher for daytime sleepiness (13.0, females vs 9.0, males; p < 0.001), with pathological scores for daytime sleepiness. No significant gender differences were found in the resilience or empathy scores. The focus group assessment revealed difficulty in concentration and knowledge acquisition, insecurity, feelings of loss, greater critical perception, self-doubt and difficulty in creating effective bonds to support the training period as the main factors involved in the lower perception of quality of life among the women. CONCLUSIONS: In conclusion, female residents had lower scores for quality of life and higher scores for daytime sleepiness. Measures to improve quality of life among female residents during this critical period of medical training might include investing in mentoring to help them better manage their time and encouraging activities that facilitate relationship development.
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Medicina Interna/educación , Calidad de Vida/psicología , Resiliencia Psicológica , Estudiantes de Medicina/psicología , Adulto , Síntomas Afectivos , Actitud del Personal de Salud , Competencia Clínica , Estudios Transversales , Femenino , Grupos Focales , Humanos , Masculino , Investigación Cualitativa , Factores Sexuales , Estudiantes de Medicina/estadística & datos numéricos , Adulto JovenRESUMEN
Background. CrataBL is a protein isolated from Crataeva tapia bark. It has been shown to exhibit several biological properties, including anti-inflammatory, analgesic, antitumor, and insecticidal activities. There are no studies evaluating the role of CrataBL in experimental asthma models. Aim. To evaluate the effects of CrataBL on lung mechanics, inflammation, remodeling, and oxidative stress activation of mice with allergic pulmonary inflammation. Materials and Methods. BALB/c mice (6-7 weeks old, 25-30g) were divided into four groups: nonsensitized and nontreated mice (C group, n=8); ovalbumin- (OVA-) sensitized and nontreated mice (OVA group, n=8); nonsensitized and CrataBL-treated mice (C+CR group, n=8); OVA-sensitized and CrataBL-treated mice (OVA+CR group, n=8). We evaluated hyperresponsiveness to methacholine, bronchoalveolar lavage fluid (BALF), pulmonary inflammation, extracellular matrix remodeling, and oxidative stress markers. Results. CrataBL treatment in OVA-sensitized mice (OVA+CR group) attenuated the following variables compared to OVA-sensitized mice without treatment (OVA group) (all p<0.05): (1) respiratory system resistance (Rrs) and elastance (Ers) after methacholine challenge; (2) total cells, macrophages, polymorphonuclear cells, and lymphocytes in BALF; (3) eosinophils and volume fraction of collagen and elastic fibers in the airway and alveolar wall according to histopathological and morphometry analysis; (4) IL-4-, IL-5-, IL-13-, IL-17-, IFN-γ-, MMP-9-, TIMP-1-, TGF-ß-, iNOS-, and NF-kB-positive cells and volume of 8-iso-PGF2α in airway and alveolar septa according to immunohistochemistry; and (5) IL-4, IL-5, and IFN-γ according to an ELISA. Conclusion. CrataBL contributes to the control of hyperresponsiveness, pulmonary inflammation, extracellular matrix remodeling, and oxidative stress responses in an animal model of chronic allergic pulmonary inflammation.
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Asma/tratamiento farmacológico , Inhibidores Enzimáticos/farmacología , Lectinas de Plantas/farmacología , Proteínas de Plantas/farmacología , Animales , Asma/metabolismo , Pruebas de Provocación Bronquial/métodos , Líquido del Lavado Bronquioalveolar/química , Capparaceae/química , Modelos Animales de Enfermedad , Eosinófilos/efectos de los fármacos , Eosinófilos/metabolismo , Hipersensibilidad/tratamiento farmacológico , Hipersensibilidad/metabolismo , Interleucina-13/metabolismo , Interleucina-4/metabolismo , Pulmón/efectos de los fármacos , Pulmón/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Ovalbúmina/farmacología , Neumonía/tratamiento farmacológico , Neumonía/metabolismoRESUMEN
Work-exacerbated asthma (WEA) is defined as preexisting asthma that worsens with exposure to irritants [e.g., chlorine (Cl2) derivatives] in the workplace. The maximum allowable concentration in the workplace of Cl2 exposure is 3 mg/ m3 (described in OSHA). We investigated in an experimental asthma model in mice the effects of a single exposure to a sodium hypochlorite dose with this allowed chlorine concentration and a tenfold higher dose. Acute chlorine exposure at 3.3 mg/m3 in the OVA-sensitized group increased eosinophils in the peribronquial infiltrate, cytokine production, nasal mucus production and the number of iNOS positive cells in the distal lung compared to only sensitized mice. The exposure to a higher dose of 33.3 mg/m3 in the OVA-sensitized group resulted in an increase in respiratory system elastance, in the total and differential numbers of inflammatory cells in bronchoalveolar lavage fluid, IL-4, IL-5, and IL-17 in the lungs, eosinophils in peribronquial infiltrate and mucus content in nasal compared to non-exposed and sensitized animals. In this asthma model, chorine exposures at an allowable dose, contributed to the potentiation of Th2 responses. The functional alterations were associated with increased iNOS and ROCK-2 activation in the distal lung.
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Asma/fisiopatología , Cloro/efectos adversos , Alérgenos , Animales , Líquido del Lavado Bronquioalveolar/citología , Citocinas , Modelos Animales de Enfermedad , Eosinófilos/inmunología , Inflamación , Pulmón/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Mucosa Nasal/efectos de los fármacos , Óxido Nítrico Sintasa de Tipo II/metabolismo , Pruebas de Función Respiratoria , Células Th2/metabolismo , Quinasas Asociadas a rho/metabolismoRESUMEN
PURPOSE: Obesity results in decreased lung function and increased inflammation. Moderate aerobic exercise (AE) reduced lung inflammation and remodeling in a variety of respiratory disease models. Therefore, this study investigated whether AE can attenuate a diet-induced obesity respiratory phenotype; including airway hyper-responsiveness (AHR), remodeling and inflammation. METHODS: Sixty C57Bl/6 male mice were distributed into four groups: control lean (CL), exercise lean (EL), obese (O) and obese exercise (OE) groups (2 sets of 7 and 8 mice per group; nâ¯=â¯15). A classical model of diet-induced obesity (DIO) over 12â¯weeks was used. AE was performed 60â¯min/day, 5â¯days/week for 5â¯weeks. Airway hyperresponsiveness (AHR), lung inflammation and remodeling, adipokines and cytokines in bronchoalveolar lavage (BAL) was determined. RESULTS: A high fat diet over 18â¯weeks significantly increased body weight (pâ¯<â¯.0001). Five weeks of AE significantly reduced both AHR and pulmonary inflammation. AHR in obese mice that exercised was reduced at the basal level (pâ¯<â¯.05), vehicle (PBS) (pâ¯<â¯.05), 6.25 MCh mg/mL (pâ¯<â¯.05), 12.5 MCh mg/mL (pâ¯<â¯.01), 25 MCh mg/mL (pâ¯<â¯.01) and 50 MCh mg/mL (pâ¯<â¯.05). Collagen (pâ¯<â¯.001) and elastic (pâ¯<â¯.001) fiber deposition in airway wall and also smooth muscle thickness (pâ¯<â¯.001) were reduced. The number of neutrophils (pâ¯<â¯.001), macrophages (pâ¯<â¯.001) and lymphocytes (pâ¯<â¯.01) were reduced in the peribronchial space as well as in the BAL: lymphocytes (pâ¯<â¯.01), macrophages (pâ¯<â¯.01), neutrophils (pâ¯<â¯.001). AE reduced obesity markers leptin (pâ¯<â¯.001), IGF-1 (pâ¯<â¯.01) and VEGF (pâ¯<â¯.001), while increased adiponectin (pâ¯<â¯.01) in BAL. AE also reduced pro-inflammatory cytokines in the BAL: IL-1ß (pâ¯<â¯.001), IL-12p40 (pâ¯<â¯.001), IL-13 (pâ¯<â¯.01), IL-17 (pâ¯<â¯.001, IL-23 (pâ¯<â¯.05) and TNF-alpha (pâ¯<â¯.05), and increased anti-inflammatory cytokine IL-10 (pâ¯<â¯.05). CONCLUSIONS: Aerobic exercise reduces high fat diet-induced obese lung phenotype (AHR, pulmonary remodeling and inflammation), involving anti-inflammatory cytokine IL-10 and adiponectin.
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Obesidad/complicaciones , Condicionamiento Físico Animal , Hipersensibilidad Respiratoria/etiología , Hipersensibilidad Respiratoria/prevención & control , Animales , Biomarcadores/metabolismo , Colágeno/metabolismo , Dieta Alta en Grasa , Elastina/metabolismo , Inflamación/patología , Masculino , Ratones Endogámicos C57BL , FenotipoRESUMEN
Clinical studies in asthma are not able to clear up all aspects of disease pathophysiology. Animal models have been developed to better understand these mechanisms and to evaluate both safety and efficacy of therapies before starting clinical trials. Several species of animals have been used in experimental models of asthma, such as Drosophila, rats, guinea pigs, cats, dogs, pigs, primates and equines. However, the most common species studied in the last two decades is mice, particularly BALB/c. Animal models of asthma try to mimic the pathophysiology of human disease. They classically include two phases: sensitization and challenge. Sensitization is traditionally performed by intraperitoneal and subcutaneous routes, but intranasal instillation of allergens has been increasingly used because human asthma is induced by inhalation of allergens. Challenges with allergens are performed through aerosol, intranasal or intratracheal instillation. However, few studies have compared different routes of sensitization and challenge. The causative allergen is another important issue in developing a good animal model. Despite being more traditional and leading to intense inflammation, ovalbumin has been replaced by aeroallergens, such as house dust mites, to use the allergens that cause human disease. Finally, researchers should define outcomes to be evaluated, such as serum-specific antibodies, airway hyperresponsiveness, inflammation and remodeling. The present review analyzes the animal models of asthma, assessing differences between species, allergens and routes of allergen administration.
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Asthma is an allergic lung disease and, when associated to cigarette smoke exposition, some patients show controversial signs about lung function and other inflammatory mediators. Epidemiologic and experimental studies have shown both increasing and decreasing inflammation in lungs of subjects with asthma and exposed to cigarette smoke. Therefore, in this study, we analyzed how cigarette smoke affects pro-inflammatory and anti-inflammatory mediators in a murine model of allergic pulmonary inflammation. We sensitized Balb/c mice to ovalbumin (OVA) with two intraperitoneal injections. After sensitization, the animals were exposed to cigarette smoke twice a day, 30 min per exposition, for 12 consecutive days. In order to drive the cell to the lungs, four aerosol challenges were performed every 48 h with the same allergen of sensitization. OVA sensitization and challenge developed pulmonary Th2 characteristic response with increased airway responsiveness, remodeling, increased levels of IgE, interleukin (IL)-4, and IL-13. Cigarette smoke, unexpectedly, reduced the levels of IL-4 and IL-13 and simultaneously decreased anti-inflammatory cytokines as IL-10 and transforming growth factor (TGF)-ß in sensitized and challenged animals. OVA combined with cigarette smoke exposition decreased the number of eosinophils in bronchoalveolar lavage and increased the number of neutrophils in lung. The combination of cigarette smoke and lung allergy increased recruitment of lymphoid dendritic cells (DCs) into lymph nodes, which may be the leading cause to an increase in number and activation of CD8+ T cells in lungs. In addition, lung allergy and cigarette smoke exposure decreased an important regulatory subtype of DC such as plasmacytoid DC as well as its activation by expression of CD86, PDL2, and ICOSL, and it was sufficient to decrease T regs influx and anti-inflammatory cytokines release such as IL-10 and TGF-ß but not enough to diminish the structural changes. In conclusion, we observed, in this model, that OVA sensitization and challenge combined with cigarette smoke exposure leads to mischaracterization of the Th2 response of asthma by decreasing the number of eosinophils, IL-4, and IL-13 and increasing number of neutrophils, which is related to the increased number of CD8É+ DCs and CD8+ T cells as well as reduction of the regulatory cells and its released cytokines.
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Objetivo: Adjuvantes, como lipopolissacárides bacterianos, vêm sendo estudados para melhorar a eficácia da imunoterapia alérgeno-específica. A vacina de Bordetella pertussis (Pw) mostrou ter papel protetor em modelos de asma induzida por ovalbumina. Porém, seu papel na alergia a ácaros é desconhecido. Avaliamos os efeitos da vacina difteria-tétano-coqueluche (DTPw) em um modelo murino de alergia respiratória induzida por Dermatophagoides pteronyssinus (Derp). Métodos: Num protocolo de 30 dias, camundongos BALB/c foram imunizados por via subcutânea com salina ou Derp, isoladamente ou associados às vacinas de difteria-tétano (DT) ou DTPw (dias 0, 7 e 14). Posteriormente, os animais sofreram desafio intranasal diariamente com salina ou Derp (dias 22 a 28) e foram sacrificados (dia 29). Avaliamos imunoglobulinas séricas específicas, celularidade no lavado bronco-alveolar (BAL), remodelamento das vias aéreas inferiores, densidade de leucócitos polimorfonucleares (PMN) e área de muco ácido no epitélio nasal. Resultados: Os animais sensibilizados com Derp produziram altos níveis de imunoglobulinas específicas, apresentaram aumento da densidade de PMN e da área de muco ácido nasal, elevação da celularidade no BAL e remodelamento. As vacinas levaram à redução dos níveis de IgE, sendo o grupo Derp-DTPw similar aos grupos salina. Os grupos vacinados tiveram redução da celularidade no BAL e do remodelamento, com resultados mais expressivos no grupo Derp-DTPw em relação ao Derp-DT. As vacinas DT e DTPw inibiram o infiltrado PMN nasal e DTPw modulou a produção do muco ácido. Conclusões: A vacina DTPw diminuiu a IgE específica sérica, inflamação nasal e pulmonar e o remodelamento das vias respiratórias inferiores.
Objective: Adjuvant therapies, such as the use of bacterial lipopolysaccharides, have been evaluated as tools to improve the effectiveness of allergen-specific immunotherapy. Bordetella pertussis vaccine (Pw) has been shown to have a protective role in asthma models induced by ovalbumin. Conversely, its role in allergy to dust mites is unknown. We evaluated the effects of diphtheria-tetanus-pertussis vaccine (DTPw) in a murine model of respiratory allergy induced by Dermatophagoides pteronyssinus (Derp). Methods: Over a 30-day protocol, BALB/c mice were immunized subcutaneously with saline or Derp, alone or combined with diphtheria-tetanus vaccine (DT) or DTPw (days 0, 7, and 14). Then, they were subjected to intranasal challenge with saline or Derp daily (days 22 to 28), and sacrificed on day 29. We evaluated serum specific immunoglobulins, bronchoalveolar lavage (BAL) cellularity, lower airway remodeling, density of polymorphonuclear leukocytes (PMN), and acidic mucus area in the nasal epithelium. Results: Animals sensitized to Derp produced high levels of specific immunoglobulins, showed increased PMN density and acidic mucus in the nasal mucosa, and elevated BAL cellularity and remodeling. Vaccines led to the reduction of IgE levels, with the Derp-DTPw group showing similar results to those of the saline groups. Vaccinated groups showed reduced BAL cellularity and airway remodeling, with more expressive results in the Derp-DTPw group compared to Derp-DT. DT and DTPw vaccines inhibited PMN infiltration in nasal mucosa, and DTPw modulated the production of acidic nasal mucus. Conclusions: DTPw vaccine decreased serum specific IgE, nasal and pulmonary inflammation, and lower airway remodeling.
Asunto(s)
Animales , Asma , Bordetella pertussis , Inmunoglobulina E , Vacuna contra Difteria, Tétanos y Tos Ferina , Dermatophagoides pteronyssinus , Rinitis Alérgica , Inmunoterapia , Alérgenos , Modelos Animales , Remodelación de las Vías Aéreas (Respiratorias) , Inflamación , ÁcarosRESUMEN
INTRODUCTION: Leukotrienes (LTs) play a central role in asthma. Low- to moderate-intensity aerobic exercise (AE) reduces asthmatic inflammation in clinical studies and in experimental models. This study investigated whether AE attenuates LT pathway activation in an ovalbumin (OVA) model of asthma. METHODS: Sixty-four male, BALB/c mice were distributed into Control, Exercise (Exe), OVA, and OVA + Exe groups. Treadmill training was performed at moderate intensity, 5×/week, 1 h/session for 4 weeks. Quantification of bronchoalveolar lavage (BAL) cellularity, leukocytes, airway remodeling, interleukin (IL)-5, IL-13, cysteinyl leukotriene (CysLT), and leukotriene B4 (LTB4) in BAL was performed. In addition, quantitative analyses on peribronchial leukocytes and airway epithelium for LT pathway agents: 5-lypoxygenase (5-LO), LTA4 hydrolase (LTA4H), CysLT1 receptor, CysLT2 receptor, LTC4 synthase, and LTB4 receptor 2 (BLT2) were performed. Airway hyperresponsiveness (AHR) to methacholine (MCh) was assessed via whole body plethysmography. RESULTS: AE decreased eosinophils (p < 0.001), neutrophils (p > 0.001), lymphocytes (p < 0.001), and macrophages (p < 0.01) in BAL, as well as eosinophils (p < 0.01), lymphocytes (p < 0.001), and macrophages (p > 0.001) in airway walls. Collagen (p < 0.01), elastic fibers (p < 0.01), mucus production (p < 0.01), and smooth muscle thickness (p < 0.01), as well as IL-5 (p < 0.01), IL-13 (p < 0.01), CysLT (p < 0.01), and LTB4 (p < 0.01) in BAL were reduced. 5-LO (p < 0.05), LTA4H (p < 0.05), CysLT1 receptor (p < 0.001), CysLT2 receptor (p < 0.001), LTC4 synthase (p < 0.001), and BLT2 (p < 0.01) expression by peribronchial leukocytes and airway epithelium were reduced. Lastly, AHR to MCh 25 mg/mL (p < 0.05) and 50 mg/mL (p < 0.01) was reduced. CONCLUSION: Moderate-intensity AE attenuated asthma phenotype and LT production in both pulmonary leukocytes and airway epithelium of OVA-treated mice.
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ABSTRACT Objective To develop a new experimental model of chronic allergic pulmonary disease induced by house dust mite, with marked production of specific immunoglobulin E (IgE), eosinophilic inflammatory infiltrate in the airways and remodeling, comparing two different routes of sensitization. Methods The protocol lasted 30 days. BALB/c mice were divided into six groups and were sensitized subcutaneously or intraperitoneally with saline (negative control), Dermatophagoides pteronyssinus (Der p) 50 or 500mcg in three injections. Subsequently they underwent intranasal challenge with Der p or saline for 7 days and were sacrificed 24 hours after the last challenge. We evaluated the titration of specific IgE anti-Der p, eosinophilic density in peribronchovascular space and airway remodeling. Results Both animals sensitized intraperitoneally and subcutaneously produced specific IgE anti-Der p. Peribronchovascular eosinophilia increased only in mice receiving lower doses of Der p. However, only the group sensitized with Der p 50mcg through subcutaneously route showed significant airway remodeling. Conclusion In this murine model of asthma, both pathways of sensitization led to the production of specific IgE and eosinophilia in the airways. However, only the subcutaneously route was able to induce remodeling. Furthermore, lower doses of Der p used in sensitization were better than higher ones, suggesting immune tolerance. Further studies are required to evaluate the efficacy of this model in the development of bronchial hyperresponsiveness, but it can already be replicated in experiments to create new therapeutic drugs or immunotherapeutic strategies.
RESUMO Objetivo Desenvolver um novo modelo experimental de doença pulmonar alérgica crônica por ácaro, com proeminente produção de imunoglobulina E (IgE) específica, infiltrado inflamatório eosinofílico nas vias aéreas e remodelamento, comparando duas vias diferentes de sensibilização. Métodos O protocolo teve duração de 30 dias. Camundongos BALB/c foram divididos em seis grupos submetidos à sensibilização por via subcutânea ou intraperitoneal com solução salina (controles negativos),Dermatophagoides pteronyssinus (Der p) 50 ou 500mcg, em três aplicações. Posteriormente, foram submetidos à provocação intranasal com Der p ou salina por 7 dias e sacrificados 24 horas após o último desafio. Avaliamos a titulação de IgE específica anti-Der p, densidade eosinofílica no espaço peribroncovascular e remodelamento das vias aéreas. Resultados Tanto os animais sensibilizados por via subcutânea como intraperitoneal produziram IgE específica anti-Der p. Ocorreu aumento da eosinofilia peribroncovascular apenas nos animais que receberam menor dose de Der p. Porém apenas o grupo sensibilizado com Der p 50mcg subcutânea apresentou remodelamento significativo das vias aéreas. Conclusão Neste modelo murino de asma, as duas vias de sensibilização levaram à produção de IgE específica e eosinofilia nas vias aéreas. No entanto, apenas a via subcutânea foi capaz de induzir ao remodelamento. Além disso, doses menores de Der p utilizadas foram superiores às mais elevadas, sugerindo tolerância. Mais estudos são necessários para avaliar a eficácia deste modelo no desenvolvimento da hiperresponsividade brônquica, mas ele pode ser replicado em experimentos para criação de novas estratégias terapêuticas medicamentosas ou imunoterápicas.
Asunto(s)
Animales , Masculino , Alérgenos/administración & dosificación , Asma/inmunología , Modelos Animales de Enfermedad , Inmunización/métodos , Pyroglyphidae , Administración Intranasal , Asma/fisiopatología , Pruebas de Provocación Bronquial , Ensayo de Inmunoadsorción Enzimática , Eosinófilos/metabolismo , Colágenos Fibrilares/metabolismo , Inyecciones Intraperitoneales , Inyecciones Subcutáneas , Inmunoglobulina E/sangre , Inmunoglobulina G/sangre , Recuento de Leucocitos , Ratones Endogámicos BALB C , Anafilaxis Cutánea Pasiva/inmunología , Eosinofilia Pulmonar/parasitologíaRESUMEN
OBJECTIVE: To develop a new experimental model of chronic allergic pulmonary disease induced by house dust mite, with marked production of specific immunoglobulin E (IgE), eosinophilic inflammatory infiltrate in the airways and remodeling, comparing two different routes of sensitization. METHODS: The protocol lasted 30 days. BALB/c mice were divided into six groups and were sensitized subcutaneously or intraperitoneally with saline (negative control), Dermatophagoides pteronyssinus (Der p) 50 or 500 mcg in three injections. Subsequently they underwent intranasal challenge with Der p or saline for 7 days and were sacrificed 24 hours after the last challenge. We evaluated the titration of specific IgE anti-Der p, eosinophilic density in peribronchovascular space and airway remodeling. RESULTS: Both animals sensitized intraperitoneally and subcutaneously produced specific IgE anti-Der p. Peribronchovascular eosinophilia increased only in mice receiving lower doses of Der p. However, only the group sensitized with Der p 50 mcg through subcutaneously route showed significant airway remodeling. CONCLUSION: In this murine model of asthma, both pathways of sensitization led to the production of specific IgE and eosinophilia in the airways. However, only the subcutaneously route was able to induce remodeling. Furthermore, lower doses of Der p used in sensitization were better than higher ones, suggesting immune tolerance. Further studies are required to evaluate the efficacy of this model in the development of bronchial hyperresponsiveness, but it can already be replicated in experiments to create new therapeutic drugs or immunotherapeutic strategies.
Asunto(s)
Alérgenos/administración & dosificación , Asma/inmunología , Modelos Animales de Enfermedad , Inmunización/métodos , Pyroglyphidae , Administración Intranasal , Animales , Asma/fisiopatología , Pruebas de Provocación Bronquial , Ensayo de Inmunoadsorción Enzimática , Eosinófilos/metabolismo , Colágenos Fibrilares/metabolismo , Inmunoglobulina E/sangre , Inmunoglobulina G/sangre , Inyecciones Intraperitoneales , Inyecciones Subcutáneas , Recuento de Leucocitos , Masculino , Ratones Endogámicos BALB C , Anafilaxis Cutánea Pasiva/inmunología , Eosinofilia Pulmonar/parasitologíaRESUMEN
Studies suggest that airborne pollutants are important cofactors in the exacerbation of lung diseases. The role of DC on the exacerbation of lung inflammation induced by particulate matter pollutants is unclear. We evaluated the effects of residual oil fly ash (ROFA) on the phenotype and function of bone marrow-derived dendritic cells (BMDCs) in vitro and lung dendritic cells (DCs) in vivo, and the subsequent T-cell response. In a model of asthma, exposure to ROFA exacerbated pulmonary inflammation, which was attributed to the increase of eosinophils, IL-5- and IFN-γ-producing T cells, and goblet cells as well as decreased number of Treg and pDC. However, the ROFA showed no ability to modulate the production of anaphylactic IgE. In vitro studies showed that ROFA directly induced the maturation of DCs up-regulating the expression of co-stimulatory molecules and cytokines and MMP production in an uptake-dependent and oxidative stress-dependent manner. Furthermore, ROFA-pulsed BMDC transferred to allergic mice exacerbated eosinophilic inflammation as well as promoted increased epithelial and goblet cells changes. Thus, pollutants may constitute an important and risk factor in the exacerbation of asthma with inhibition of the negative regulatory signals in the lung, with enhanced mDC activation that sustains the recruitment of effector T lymphocytes and eosinophil.
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Asma/inmunología , Ceniza del Carbón/administración & dosificación , Células Dendríticas/inmunología , Pulmón/inmunología , Material Particulado/administración & dosificación , Animales , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Endocitosis , Eosinófilos/inmunología , Femenino , Células Caliciformes/inmunología , Humanos , Interferón gamma/metabolismo , Interleucina-5/metabolismo , Activación de Linfocitos , Ratones Endogámicos BALB C , Subgrupos de Linfocitos T/inmunologíaRESUMEN
Maternal immunization with allergens, such as ovalbumin (OVA), can inhibit the development of an allergic response in offspring. The regulatory mechanisms seem to be mediated by maternal antibodies (MatAbs) and factors generated by the maternal-fetal interface. The aim of this study was to verify the pathways of inhibitory Ab transference after maternal immunization with OVA and the effect of the offspring's dendritic cells (DCs) on the generation of regulatory T (Treg) cells. We verified that preconceptional OVA immunization induces high levels of proinflammatory and regulatory cytokines in the amniotic fluid, allowing the transference of high levels of anti-OVA IgG1 Abs to the offspring. Using an adoptive nursing protocol, we verified that maternal immunization leads to MatAb transference by the placental route and by breastfeeding contribute to the inhibition of anaphylactic IgE and IgG1 Ab responses in immunized offspring. We observed that maternal immunization decreased eosinophil numbers in recovered bronchoalveolar lavage fluid and in the lung tissue, whereas with a lack of control of airway responsiveness to methacholine. Maternal immunization induced in young offspring a decreased percentage of CD11c+ DCs expressing MHC class II and CD40 molecules. Moreover, DCs from both groups of offspring when pulsed with OVA, were able to induce Treg cells in vitro. Similarly, OVA immunization at the neonatal stage increased the frequency of Treg cells, regardless of the mother's immunization status. These findings emphasize that maternal immunization leads to a complex interaction of regulatory factors, with MatAbs, DCs and Treg cells affecting the tolerance of offspring during an allergic response.