RESUMO
Introduction: Currently, Chronic Obstructive Pulmonary Disease (COPD) has a high impact on morbidity and mortality worldwide. The increase of CD4+, CD8+ cells expressing NF-κB, STAT4, IFN-γ and perforin are related to smoking habit, smoking history, airflow rate, obstruction and pulmonary emphysema. Furthermore, a deficiency in CD4+CD25+Foxp3+ regulatory T cells (Tregs) may impair the normal function of the immune system and lead to respiratory immune disease. On the other hand, the anti-inflammatory cytokine IL-10, produced by Treg cells and macrophages, inhibits the synthesis of several pro-inflammatory cytokines that are expressed in COPD. Therefore, immunotherapeutic strategies, such as Photobiomodulation (PBM), aim to regulate the levels of cytokines, chemokines and transcription factors in COPD. Consequently, the objective of this study was to evaluate CD4+STAT4 and CD4+CD25+Foxp3+ cells as well as the production of CD4+IFN- γ and CD4+CD25+IL-10 in the lung after PBM therapy in a COPD mice model. Methods: We induced COPD in C57BL/6 mice through an orotracheal application of cigarette smoke extract. PMB treatment was applied for the entire 7 weeks and Bronchoalveolar lavage (BAL) and lungs were collected to study production of IFN- γ and IL-10 in the lung. After the last administration with cigarette smoke extract (end of 7 weeks), 24 h later, the animals were euthanized. One-way ANOVA followed by NewmanKeuls test were used for statistical analysis with significance levels adjusted to 5% (p < 0.05). Results: This result showed that PBM improves COPD symptomatology, reducing the number of inflammatory cells (macrophages, neutrophils and lymphocytes), the levels of IFN-γ among others, and increased IL-10. We also observed a decrease of collagen, mucus, bronchoconstriction index, alveolar enlargement, CD4+, CD8+, CD4+STAT4+, and CD4+IFN-γ+ cells. In addition, in the treated group, we found an increase in CD4+CD25+Foxp3+ and CD4+IL-10+ T cells. Conclusion: This study suggests that PBM treatment could be applied as an immunotherapeutic strategy for COPD.
RESUMO
Objectives: Some pro-inflammatory lipids derived from 1 lipooxygenase enzyme are potent neutrophil chemoattractant, a cell centrally involved in acute respiratory distress syndrome (ARDS); a syndrome lacking effective treatment. Considering the beneficial effects of the leukotriene receptor inhibitor, montelukast, on other lung diseases, whether montelukast attenuates inflammation in a mouse model of ARDS, and whether it reduces LPS stimulated activation of human neutrophils was investigated. Methods: Thirty-five C57Bl/6 mice were distributed into control (PBS) + 24h, LPS + 24h (10 μg/mouse), control + 48 h, LPS+48 h, and LPS 48 h+Montelukast (10 mg/kg). In addition, human neutrophils were incubated with LPS ( 1μg/mL) and treated with montelukast (10 μM). Results: Oral-tracheal administration of montelukast significantly attenuated total cells (P < .05), macrophages (P < .05), neutrophils (P < .01), lymphocytes (P < .001) and total protein levels in BAL (P < .05), as well as IL-6 (P < .05), CXCL1/KC (P < .05), IL-17 (P < .05) and TNF-alfa (P < .05). Furthermore, montelukast reduced neutrophils (P < .001), lymphocytes (P < .01) and macrophages (P < .01) in the lung parenchyma. In addition, montelukast restored BAL VEGF levels (P < .05). LTB4 receptor expression (P < .001) as well as NF-κB (P <. 001), a downstream target of LPS, were also reduced in lung parenchymal leukocytes. Furthermore, montelukast reduced IL-8 (P < .001) production by LPS-treated human neutrophils. Conclusion: In conclusion, montelukast efficiently attenuated both LPS-induced lung inflammation in a mouse model of ARDS and in LPS challenged human neutrophils
Objetivos: Algunos lípidos proinflamatorios derivados de la enzima lipooxigenasa 1 son potentes quimioatrayentes de neutrófilos, un tipo celular con una implicación principal en el síndrome de distrés respiratorio agudo (SDRA), para el que no hay tratamiento efectivo. Considerando los efectos beneficiosos del inhibidor de los receptores de leucotrienos montelukast en otras enfermedades pulmonares, se investigó si este fármaco era capaz de atenuar la inflamación en un modelo de ratón de SDRA y de reducir la activación de los neutrófilos humanos inducida por LPS. Métodos: Se utilizaron 35 ratones C57BL/6 distribuidos en los siguientes grupos: control (PBS) + 24 h, LPS+(24 h [10 μg/ratón]), control + 48 h y LPS 48 h + montelukast (10 mg/kg). Por otro lado, se incubaron neutrófilos humanos con LPS (1 μg/ml) y se trataron con montelukast (10 μM). Resultados: La administración orotraqueal de montelukast redujo el número total de células (p < 0,05), de macrófagos (p < 0,05), de neutrófilos (p < 0,01), de linfocitos (p < 0,001) y los niveles totales de proteína en el lavado broncoalveolar (p < 0,05), así como de IL-6 (p < 0,05), CXCL1/KC (p < 0,05), IL-17 (p < 0,05) y TNF-alfa (p < 0,05). Además, el montelukast redujo los neutrófilos (p < 0,001), los linfocitos (p < 0,01) y los macrófagos (p < 0,01) en el parénquima pulmonar. Asimismo, restauró los niveles de VEGF en el lavado broncoalveolar (p < 0,05) y disminuyó la expresión del receptor LTB4 (p < 0,001) y de NF-κB (p < 0,001), una diana downstream del LPS, en los leucocitos del parénquima pulmonar. Por último, redujo la producción de IL-8 por parte de los neutrófilos humanos tratados con LPS. Conclusión: En conclusión, el montelukast atenuó de manera eficaz tanto la inflamación pulmonar inducida por LPS en un modelo de ratón de SDRA como en neutrófilos humanos estimulados con LPS