背景:肥胖哮喘是一种哮喘表型,比过敏性哮喘引起更严重的肺部炎症和气道高反应性,并且对常规治疗有抵抗力。InvolucrasinB(IB)是一种二氢类黄酮,从shuteriainspecucrata(Wall。)怀特和阿恩。,在中国南方使用传统的“Dai”和“Wa”药物来治疗“痰湿痰”(肥胖症)以及肺部炎症。然而,IB是否能改善肥胖哮喘尚不清楚,而IB特异性靶向的肥胖哮喘的潜在机制和分子表达仍不完全清楚。
方法:以屋尘螨(HDMs)和高脂饮食(HFD)为诱导剂,建立肥胖哮喘的体内C57BL/6J小鼠模型,以评估IB的治疗效果。人THP-1单核细胞培养物的体外细胞培养物用于研究用脂多糖(LPS)和棕榈酸(PA)处理后IB的作用。
结果:体内,我们发现,IB干预可改善气道高反应性和肺组织病理学,并显著抑制相关炎症因子的分泌,如白细胞介素(IL)-1β,IL-17A,和支气管肺泡灌洗液中的IL-22,血清总IgE和HDM-IgE与模型组(HFD+HDM)比较。结果表明,IB可以降低肺组织中粒细胞受体1(Gr-1)和中性粒细胞胞外陷阱(NETs)的表达,以及NLR家族pyrin结构域包含3(NLRP3)和诱导型一氧化氮合酶在M1巨噬细胞(M1)中的表达。IB也减少了ILC3/Th17细胞的数量,负责产生IL-17A,中性粒细胞介导的炎症的关键介质,证实IB在肥胖相关哮喘中的治疗作用与中性粒细胞和M1细胞有关。此外,IB调节脂质代谢并抑制脂肪组织中巨噬细胞的产生。体外实验结果表明,IB抑制IL-1β的分泌,来自THP-1细胞的IL-18和肿瘤坏死因子-α(TNF-α),与模型组相比,THP-1细胞中NLRP3相关蛋白的表达(LPS,PA,和LPS+PA),证实IB的作用涉及TLR4-NF-κB-NLRP3途径。
结论:本研究首次证明了IB在肥胖哮喘中的治疗作用,并进一步阐明了其作为TLR4-NF-κB-NLRP3通路的机制。
BACKGROUND: Obese asthma is an asthma phenotype that causes more severe lung inflammation and airway hyperresponsiveness than allergic asthma and it is resistant to conventional therapy. Involucrasin B (IB) is a dihydroflavonoid isolated from Shuteria involucrata (Wall.) Wight & Arn., a traditional \"Dai\" and \"Wa\" medicine was used in southern China to treat the \"phlegm and wetness of sputum\" (obesity disease) as well as lung inflammation. However, whether IB can ameliorate obese asthma remains unclear, and the underlying mechanisms and molecular expression in obese asthma specifically targeted by IB are still not fully understood.
METHODS: An in vivo C57BL/6 J mouse model of obese asthma was established using house dust mites (HDMs) and high-fat diet (HFD) as inducers to evaluate the therapeutic effect of IB. An in vitro cell culture of human THP-1 monocytic cell culture was used to investigate the effect of IB after the treatment with lipopolysaccharide (LPS) and palmitic acid (PA).
RESULTS: In vivo, we found that intervention with IB improved airway hyperresponsiveness and lung histopathology and significantly inhibited the secretion of relevant inflammatory factors, such as interleukin (IL)-1β, IL-17A, and IL-22 in bronchoalveolar lavage fluid, and total-IgE and HDM-IgE in serum compared with the model group (HFD+HDM). The findings indicate that IB could decrease the expression of granulocyte receptor 1 (Gr-1) and neutrophil extracellular traps (NETs) in lung tissue, as well as the expression of NLR family pyrin domain containing 3 (NLRP3) and inducible nitric oxide synthase in M1 macrophages (M1). IB also reduced the population of ILC3/Th17 cells, which are responsible for producing IL-17A, a crucial mediator of neutrophil-mediated inflammation, confirming that the therapeutic effect of IB in obesity-related asthma was related to neutrophils and M1 cells. In addition, IB regulated lipid metabolism and inhibited the production of macrophages in adipose tissue. The in vitro results revealed that IB inhibited the secretion of IL-1β, IL-18, and tumor necrosis factor-α (TNF-α) from THP-1 cells, and the expression of NLRP3-related protein in THP-1 cells compared with the model groups (LPS, PA, and LPS+PA), confirming that the action of IB involved the TLR4-NF-κB-NLRP3 pathway.
CONCLUSIONS: This study demonstrated the therapeutic effect of IB in obese asthma for the first time and further clarified its mechanistic pathway as the TLR4-NF-κB-NLRP3 pathway.