Y-27632 is associated with corticosteroid-potentiated control of pulmonary remodeling and inflammation in guinea pigs with chronic allergic inflammation.

BACKGROUND: Previously, we showed that treatment with the Rho-kinase inhibitor Y-27632 was able to control airway responsiveness, inflammation, remodeling, and oxidative stress in an animal model of asthma, suggesting that this drug is beneficial in asthma. However, studies evaluating the effects of these inhibitors in conjunction with corticosteroids on chronic pulmonary inflammation have not been conducted. Therefore, we evaluated the effects of treatment with the Rho-kinase inhibitor Y-27632, with or without concurrent dexamethasone treatment, on airway and lung tissue mechanical responses, inflammation, extracellular matrix remodeling, and oxidative stress in guinea pigs with chronic allergic inflammation. METHODS: The guinea pigs were subjected to seven ovalbumin or saline inhalation exposures. Treatment with Y-27632 (1 mM) and dexamethasone (2 mg/kg) started at the fifth inhalation. Seventy-two hours after the seventh inhalation, the pulmonary mechanics were evaluated and exhaled nitric oxide (ENO) levels were determined. The lungs were removed and histological analysis was performed using morphometry. RESULTS: The treatment of guinea pigs with the Rho-kinase inhibitor and dexamethasone (ORC group) decreased ENO, the maximal mechanical responses after antigen challenge, inflammation, extracellular matrix remodeling and oxidative stress in the lungs. This therapeutic strategy reduced the levels of collagen and IFN-γ in the airway walls, as well as IL-2, IFN-γ, 8-iso-PGF2α and NF-κB in the distal parenchyma, when compared to isolated treatment with corticosteroid or Rho-kinase inhibitor (P < 0.05) and reduced the number of TIMP-1-positive cells and eosinophils in the alveolar septa compared to corticosteroid-treated animals (P < 0.05). The combined treatment with the Rho-kinase inhibitor and the corticosteroid provided maximal control over the remodeling response and inflammation in the airways and parenchyma. CONCLUSIONS: Rho-kinase inhibition, alone or in combination with corticosteroids, can be considered a future pharmacological tool for the control of asthma.

Rho-kinase inhibition attenuates airway responsiveness, inflammation, matrix remodeling, and oxidative stress activation induced by chronic inflammation.

Several studies have demonstrated the importance of Rho-kinase in the modulation of smooth muscle contraction, airway hyperresponsiveness, and inflammation. However, the effects of repeated treatment with a specific inhibitor of this pathway have not been previously investigated. We evaluated the effects of repeated treatment with Y-27632, a highly selective Rho-kinase inhibitor, on airway hyperresponsiveness, oxidative stress activation, extracellular matrix remodeling, eosinophilic inflammation, and cytokine expression in an animal model of chronic airway inflammation. Guinea pigs were subjected to seven ovalbumin or saline exposures. The treatment with Y-27632 (1 mM) started at the fifth inhalation. Seventy-two hours after the seventh inhalation, the animals' pulmonary mechanics were evaluated, and exhaled nitric oxide (E(NO)) was collected. The lungs were removed, and histological analysis was performed using morphometry. Treatment with Y-27632 in sensitized animals reduced E(NO) concentrations, maximal responses of resistance, elastance of the respiratory system, eosinophil counts, collagen and elastic fiber contents, the numbers of cells positive for IL-2, IL-4, IL-5, IL-13, inducible nitric oxide synthase, matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1, transforming growth factor-ß, NF-κB, IFN-γ, and 8-iso-prostaglandin F2α contents compared with the untreated group (P < 0.05). We observed positive correlations among the functional responses and inflammation, remodeling, and oxidative stress pathway activation markers evaluated. In conclusion, Rho-kinase pathway activation contributes to the potentiation of the hyperresponsiveness, inflammation, the extracellular matrix remodeling process, and oxidative stress activation. These results suggest that Rho-kinase inhibitors represent potential pharmacological tools for the control of asthma.

Effects of Rho-kinase inhibition in lung tissue with chronic inflammation.

We evaluated whether Rho-kinase inhibition (Y-27632) modulated distal lung responsiveness, inflammation, extracellular matrix remodeling and oxidative stress activation in guinea pigs (GPs) with chronic allergic inflammation. GPs were submitted to inhalation of ovalbumin (OVA-2×/week/4 weeks). From the 5th inhalation on, the Rho-kinase inhibitor group animals were submitted to Y-27632 inhalation 10min before each inhalation of OVA. Seventy-two hours after the seventh inhalation, the oscillatory mechanics of the distal lung strips were assessed under the baseline condition and after the ovalbumin challenge. Subsequently, the lung slices were submitted to morphometry. Rho-kinase inhibition in the ovalbumin-exposed animals attenuated distal lung elastance and resistance, eosinophils, IL-2, IL-4, IL-5, IL-13, TIMP-1, MMP-9, TGF-ß, IFN-γ, NF-κB and iNOS-positive cells and the volume fraction of 8-iso-PGF2α, elastic, collagen and actin in alveolar walls compared with the OVA group (P<0.05). Rho-kinase inhibition contributed to the control of distal lung responsiveness, eosinophilic and Th1/Th2 responses and extracellular matrix remodeling in an animal model of chronic allergic inflammation.

Tratamento com inibidor da Rho quinase em cobaias com inflamação alérgica crônica: modulação da inflamação eosinofílica, da expressão de citocinas inflamatórias, da matriz extracelular, do estresse oxidativo e da reatividade de vias aéreas / Treatment with Rho-kinase inhibitor in guinea pigs with chronic allergic inflammation: modulation of eosinophilic inflammation, expression of inflammatory cytokines, extracellular matrix, oxidative stress and airway responsiveness

INTRODUÇÃO: Vários estudos têm mostrado a importância da Rho quinase na modulação da contração do músculo liso, hiperresponsividade das vias aéreas e inflamação. Entretanto, os efeitos do tratamento crônico com um inibidor específico desta via não haviam sido previamente investigados. MÉTODOS: No presente estudo, foram avaliados os efeitos do tratamento crônico com Y-27632, um inibidor altamente seletivo Rho quinase, sobre a hiperresponsividade das vias aéreas, a ativação do estresse oxidativo, o remodelamento da matriz extracelular, a inflamação eosinofílica e a expressão de citocinas em um modelo animal de inflamação crônica das vias aéreas. As cobaias foram submetidas a sete inalações com ovalbumina ou solução salina (duas vezes por semana durante quatro semanas). Inalações com o inibidor da Rho quinase (Y-27632; 1mM) foram realizadas 10 min antes de cada exposição ao antígeno, começando na quinta inalação. Setenta e duas horas após a 7ª inalação, a avaliação da mecânica pulmonar foi realizada e o óxido nítrico exalado foi coletado. Os pulmões foram então removidos e a análise histológica foi realizada utilizando morfometria. RESULTADOS: O tratamento com Y-27632 em animais sensibilizados reduziu o óxido nítrico exalado, as respostas máximas de resistência e elastância do sistema respiratório, o número de eosinófilos, o conteúdo colágeno e fibras elásticas, o número de células positivas para IL-2, IL-4, IL-5, IL-13, iNOS, MMP -9, TIMP-1, TGF-, NFkappa B e IFN-, e o conteúdo de 8-iso-PGF2 em relação ao grupo não tratado (p<0,05). Houve correlação positiva entre as respostas funcionais e os marcadores de inflamação, remodelamento e ativação da via de estresse oxidativo avaliados. CONCLUSÕES: A ativação da vida da Rho quinase contribui para a potencialização da hiperresponsividade, inflamação, processo de remodelamento da matriz extracelular e ativação do estresse oxidativo. Estes resultados sugerem que os inibidores da Rho quinase podem ser uma...

INTRODUCTION: Several studies have shown the importance of Rho-kinase in the modulation of smooth muscle contraction, airway hyperresponsiveness and inflammation. However, the effects of chronic treatment with a specific inhibitor of this pathway had not been previously investigated. METHODS: We evaluated the effects of chronic treatment with Y-27632, a highly selective Rho-kinase inhibitor, on airway hyperresponsiveness, oxidative stress activation, extracellular matrix remodeling, eosinophilic inflammation and cytokines expression in an animal model of chronic airway inflammation. Guinea pigs were submitted to seven ovalbumin or saline exposures (twice a week for four weeks). Rho-kinase inhibitor (Y-27632; 1mM) was aerosolized 10 min before each antigen exposure, beginning at the 5th inhalation. Seventy-two hours after the 7th inhalation, pulmonary mechanics evaluation was performed and exhaled nitric oxide was collected. Lungs were removed and histological analysis was performed using morphometry. RESULTS: Treatment with Y-27632 in sensitized animals reduced exhaled nitric oxide, maximal responses of resistance and elastance of respiratory system, eosinophils, collagen and elastic fibers content, IL-2, IL-4, IL-5, IL-13, iNOS, MMP-9, TIMP-1, TGF-, NFkappa B and IFN- positive cells, and 8-iso-PGF2 content compared to the non-treated group (P<0.05). There were positive correlations among the functional responses and the markers of inflammation, remodeling and oxidative stress pathway activation evaluated. CONCLUSIONS: Rho-kinase pathway activation contributes to the potentiation of the hyperresponsiveness, inflammation, extracellular matrix remodeling process and oxidative stress activation. These results suggest that Rho-kinase inhibitors may be a potential pharmacological tool for controlling asthma...