RESUMO
Asthma is a chronic airway inflammation that is considered a serious public health concern worldwide. Nobiletin (5,6,7,8,3',4'-hexamethyl flavonoid), an important compound isolated from several traditional Chinese medicines, especially Citri Reticulatae Pericarpium, is widely used for a number of indications, including cancer, allergic diseases, and chronic inflammation. However, the mechanism by which nobiletin exerts its anti-asthmatic effect remains unclear. In this research, we comprehensively demonstrated the anti-asthmatic effects of nobiletin in an animal model of asthma. It was found that nobiletin significantly reduced the levels of inflammatory cells and cytokines in mice and alleviated airway hyperresponsiveness. To explore the target of nobiletin, we identified PDE4B as the target of nobiletin through pharmacophore modeling, molecular docking, molecular dynamics simulation, SPR, and enzyme activity assays. Subsequently, it was found that nobiletin could activate the cAMP-PKA-CREB signaling pathway downstream of PDE4B in mouse lung tissues. Additionally, we studied the anti-inflammatory and anti-airway remodeling effects of nobiletin in LPS-induced RAW264.7 cells and TGF-ß1-induced ASM cells, confirming the activation of the cAMP-PKA-CREB signaling pathway by nobiletin. Further validation in PDE4B-deficient RAW264.7 cells confirmed that the increase in cAMP levels induced by nobiletin depended on the inhibition of PDE4B. In conclusion, nobiletin exerts anti-asthmatic activity by targeting PDE4B and activating the cAMP-PKA-CREB signaling pathway.
Assuntos
Asma , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico , Proteínas Quinases Dependentes de AMP Cíclico , AMP Cíclico , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4 , Flavonas , Transdução de Sinais , Animais , Flavonas/farmacologia , Flavonas/química , Asma/tratamento farmacológico , Asma/metabolismo , Camundongos , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , AMP Cíclico/metabolismo , Inibidores da Fosfodiesterase 4/farmacologia , Inibidores da Fosfodiesterase 4/química , Simulação de Acoplamento Molecular , Modelos Animais de Doenças , Camundongos Endogâmicos BALB C , Células RAW 264.7 , MasculinoRESUMO
Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease characterized by lung inflammation and excessive deposition of extracellular matrix components. Transforming growth factor-ß1 (TGF-ß1) induced epithelial-mesenchymal transformation of type 2 lung epithelial cells leads to excessive extracellular matrix deposition, which plays an important role in fibrosis. Our objective was to evaluate the effects of 3-cyclopropylmethoxy-4-(difluoromethoxy) benzoic acid (DGM) on pulmonary fibrosis and aimed to determine whether EMT plays a key role in the pathogenesis of pulmonary fibrosis and whether EMT can be used as a therapeutic target for DGM therapy to reduce IPF. Firstly, stimulation of in vitro cultured A549 cells to construct EMTs with TGF-ß1. DGM treatment inhibited the expression of proteins such as α-SMA, vimentin, and collagen â and increased the expression of E-cadherin. Accordingly, Smad2/3 phosphorylation levels were significantly reduced by DGM treatment. Secondly, models of tracheal instillation of bleomycin and DGM were used to treat rats to demonstrate their therapeutic effects, such as improving lung function, reducing lung inflammation and fibrosis, reducing collagen deposition, and reducing the expression of E-cadherin. In conclusion, DGM attenuates TGF-ß1-induced EMT in A549 cells and bleomycin-induced pulmonary fibrosis in rats.