Hseu You-Cheng, Tseng Yu-Fang, Ke-Hseu Jhih, Pandey Sudhir, Chen Siang-Jyun, Lin Kai-Yuan, Chang Hsueh-Wei, Way Tzong-Der, Lee Chuan-Chen, Hseu Jhih-Hsuan, Yang Hsin-Ling
Department of Cosmeceutics, College of Pharmacy, China Medical University, Taichung, Taiwan.
Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan.
J Cell Mol Med. 2025 Aug;29(16):e70803. doi: 10.1111/jcmm.70803.
Dihydromikanolide (DHK) is a natural product in Mikania species. We examined the anti-inflammatory molecular mechanisms of DHK employing in vitro RAW264.7 macrophages and in vivo BALB/c mice under LPS/ATP stimulation. We found that DHK suppressed NLRP3 inflammasome, procaspase-1 activation and then pro-inflammatory IL1β expression in LPS/ATP-stimulated RAW264.7 cells. Notably, DHK-triggered autophagy in RAW264.7 cells was demonstrated by increased LC3-II accumulation, p62/SQSTM1 expression, Beclin-1/Bcl-2 ratio and PI3K/AKT/mTOR phosphorylation. Besides, DHK increased Parkin and Pink-1 protein expressions implying mitophagy induction in RAW264.7 cells. Interestingly, DHK enhanced Nrf2 nuclear translocation and provoked antioxidant HO-1, NQO-1 and γ-GCLC expressions in RAW264.7 cells. Nrf2 knockdown reversed DHK-inhibited LPS/ATP-stimulated IL1β expression in RAW264.7 cells. Interestingly, LPS/ATP-stimulated NLRP3 inflammasome and IL1β expression were inhibited by DHK, Mito-TEMPO (a mitochondrial ROS inhibitor), or N-acetylcysteine (a ROS inhibitor). In vivo study revealed that DHK attenuated wet/dry weight ratio of lung tissue, lung neutrophil intrusions and pulmonary oedema, and reduced the increased total cells, neutrophils, TNFα and IL1β expression in bronchoalveolar lavage fluid (BALF) in LPS-stimulated BALB/c mice. DHK alleviated LPS-induced pathological alterations of lung through inhibiting NLRP3 inflammation, enhancing antioxidant Nrf2 pathway and inducing mitophagy in LPS-stimulated BALB/c mice. Dihydromikanolide may be a potential therapeutic agent for inflammatory diseases.
二氢米卡诺内酯（DHK）是薇甘菊属植物中的一种天然产物。我们在体外RAW264.7巨噬细胞和体内LPS/ATP刺激下的BALB/c小鼠中研究了DHK的抗炎分子机制。我们发现DHK在LPS/ATP刺激的RAW264.7细胞中抑制了NLRP3炎性小体、前半胱天冬酶-1的激活以及随后促炎细胞因子IL-1β的表达。值得注意的是，RAW264.7细胞中DHK引发的自噬通过LC3-II积累增加、p62/SQSTM1表达、Beclin-1/Bcl-2比值以及PI3K/AKT/mTOR磷酸化得以证实。此外，DHK增加了Parkin和Pink-1蛋白表达，这意味着RAW264.7细胞中发生了线粒体自噬诱导。有趣的是，DHK增强了RAW264.7细胞中Nrf2的核转位，并激发了抗氧化剂HO-1、NQO-1和γ-GCLC的表达。Nrf2基因敲低逆转了DHK对RAW264.7细胞中LPS/ATP刺激的IL-1β表达的抑制作用。有趣的是，DHK、线粒体ROS抑制剂Mito-TEMPO或ROS抑制剂N-乙酰半胱氨酸抑制了LPS/ATP刺激的NLRP3炎性小体和IL-1β表达。体内研究表明，DHK减轻了LPS刺激的BALB/c小鼠肺组织的湿/干重比、肺中性粒细胞浸润和肺水肿，并降低了支气管肺泡灌洗液（BALF）中总细胞、中性粒细胞、TNFα和IL-1β表达的增加。DHK通过抑制LPS刺激的BALB/c小鼠中的NLRP3炎症、增强抗氧化剂Nrf2途径和诱导线粒体自噬，减轻了LPS诱导的肺部病理改变。二氢米卡诺内酯可能是一种治疗炎症性疾病的潜在药物。
