Acute lung injury (ALI) is life-threatening disease characterized by uncontrolled inflammatory response. IKKα/β, the key kinases in the activation of NF-κB pathway, are implicated in inflammatory pulmonary injury, and represent attractive targets for ALI therapy. Brevilin A (BVA) is a sesquiterpene lactone from Centipeda minima, a Chinese herb used to treat inflammatory diseases. This study aims to investigate the inhibition of BVA on ALI, with focus on clarifying the molecular mechanisms involved in BVA-mediated anti-inflammatory activity in macrophages. Briefly, BVA significantly inhibited the production of NO and PGE2 by suppressing iNOS and COX2 expression, and suppressed the mRNA expression of IL-1β, IL-6, and TNFα in LPS/IFNγ-stimulated RAW264.7 macrophages. The anti-inflammatory activity of BVA was further confirmed in LPS/IFNγ-stimulated BMDMs and TNFα/IFNγ-exposed RAW264.7 cells. In vivo, BVA effectively attenuated LPS-induced lung damage, inflammatory infiltration, and production of pro-inflammatory cytokines, including MPO, IL-1β, IL-6, TNFα, and PGE2. Mechanistically, BVA could covalently bind to the cysteine 114 of IKKα/β, and effectively inhibiting the activity and function of IKKα/β, thereby resulting in the suppression of phosphorylation and degradation of IκBα and the subsequent activation of NF-κB signaling. Furthermore, pretreatment of DTT, a thiol ligand donor, significantly abolished BVA-mediated effects in LPS/IFNγ-stimulated RAW264.7 cells, suggesting the crucial role of the electrophilic α, β-unsaturated ketone of BVA on its anti-inflammatory activity. These results suggest that BVA ameliorates ALI through inhibition of NF-κB signaling via covalently targeting IKKα/β, raising the possibility that BVA could be effective in the treatment of ALI and other diseases harboring aberrant NF-κB signaling.
急性肺损伤(ALI)是一种以不受控制的炎症反应为特征的危及生命的疾病。IKKα/β 是激活 NF-κB 通路的关键激酶,与肺部炎症损伤有关,是治疗 ALI 的诱人靶点。布雷维林 A(Brevilin A,BVA)是一种来自蜈蚣的倍半萜内酯,是一种用于治疗炎症性疾病的中草药。本研究旨在研究 BVA 对 ALI 的抑制作用,重点是阐明 BVA 介导的巨噬细胞抗炎活性的分子机制。简言之,BVA通过抑制iNOS和COX2的表达,明显抑制NO和PGE2的产生,并抑制LPS/IFNγ刺激的RAW264.7巨噬细胞中IL-1β、IL-6和TNFα的mRNA表达。在 LPS/IFNγ 刺激的 BMDMs 和 TNFα/IFNγ 暴露的 RAW264.7 细胞中,BVA 的抗炎活性得到了进一步证实。在体内,BVA 能有效减轻 LPS 引起的肺损伤、炎症浸润和促炎细胞因子的产生,包括 MPO、IL-1β、IL-6、TNFα 和 PGE2。从机理上讲,BVA能与IKKα/β的半胱氨酸114共价结合,有效抑制IKKα/β的活性和功能,从而抑制IκBα的磷酸化和降解,进而激活NF-κB信号传导。此外,硫醇配体供体 DTT 的预处理可显著消除 BVA 在 LPS/IFNγ 刺激的 RAW264.7 细胞中介导的效应,这表明 BVA 的亲电性 α、β-不饱和酮对其抗炎活性起着关键作用。这些结果表明,BVA 通过共价靶向 IKKα/β 来抑制 NF-κB 信号传导,从而改善 ALI,这使 BVA 有可能有效治疗 ALI 和其他存在异常 NF-κB 信号传导的疾病。