Wei Ruojun, Zeng Ziyuan, Chen Sheng, Shi Yuanyuan, Ding Qi
Shenzhen Hospital, Beijing University of Chinese Medicine, Shenzhen, China.
Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China.
J Ethnopharmacol. 2025 Jun 12;349:119947. doi: 10.1016/j.jep.2025.119947. Epub 2025 May 14.
Klebsiella pneumoniae (Kp) is a significant pathogen responsible for various clinical bacterial infections, including pneumonia, sepsis, and even death. However, effective treatment options remain limited due to the rising prevalence of antimicrobial resistance. Traditional Chinese medicine (TCM) has shown potential in the treatment of bacterial pneumonia. Qingfei Litan decoction (QFLT) has been reported to alleviate symptoms in patients with bacterial pneumonia, though its precise mechanisms in regulating pulmonary inflammation remain unclear.
This study aimed to investigate the therapeutic potential of QFLT in Kp-induced pneumonia and to elucidate its underlying molecular mechanisms.
In vivo, a murine pneumonia model was established through intratracheal instillation of Kp, and QFLT was administered by oral gavage. miR-146a-5p expression was downregulated by tail vein injection of an antagomir. The therapeutic effects of QFLT on pulmonary pathology, inflammatory factors, and miR-146a-5p expression were evaluated using qRT-PCR, flow cytometry, and other methods. Bioinformatics tools were employed to predict miR-146a-5p targets and associated inflammatory pathways. In vitro, an alveolar macrophage inflammation model was established by stimulating MH-S cells with heat-inactivated Klebsiella pneumoniae (iKp), followed by QFLT treatment. Inhibition of miR-146a-5p was achieved through transfection with specific inhibitors. The effects of QFLT on inflammatory responses, miR-146a-5p expression, and TLR4/MyD88/NF-κB signaling were assessed using qRT-PCR, Western blotting (WB) and other methods.
Kp infection significantly exacerbated pulmonary inflammation and downregulated miR-146a-5p expression in both lung tissues and MH-S cells. QFLT treatment alleviated inflammatory responses and upregulated miR-146a-5p expression. Bioinformatics analysis demonstrated that miR-146a-5p targeted TRAF6, a key mediator of the TLR4/MyD88/NF-κB pathway. Western blot analysis further confirmed that QFLT reduced Kp-induced upregulation of the TLR4/MyD88/NF-κB pathway in MH-S cells. Moreover, inhibition of miR-146a-5p exacerbated inflammatory responses in both lung tissues and MH-S cells, whereas QFLT treatment effectively attenuated these inflammatory effects. Furthermore, miR-146a-5p suppression resulted in elevated expression of proteins in the TLR4/MyD88/NF-κB signaling pathway in MH-S cells, while QFLT administration significantly reduced the expression levels of these signaling components.
These findings demonstrated that QFLT ameliorated Kp-induced pneumonia by modulating the TLR4/MyD88/NF-κB axis via miR-146a-5p.
肺炎克雷伯菌（Kp）是导致各种临床细菌感染的重要病原体，包括肺炎、败血症甚至死亡。然而，由于抗菌药物耐药性的日益普遍，有效的治疗选择仍然有限。传统中医（TCM）在治疗细菌性肺炎方面已显示出潜力。清肺利痰汤（QFLT）已被报道可缓解细菌性肺炎患者的症状，但其调节肺部炎症的确切机制尚不清楚。
本研究旨在探讨QFLT对Kp诱导的肺炎的治疗潜力，并阐明其潜在的分子机制。
在体内，通过气管内注入Kp建立小鼠肺炎模型，并通过口服灌胃给予QFLT。通过尾静脉注射抗miR-146a-5p来下调miR-146a-5p的表达。使用qRT-PCR、流式细胞术和其他方法评估QFLT对肺部病理、炎症因子和miR-146a-5p表达的治疗效果。利用生物信息学工具预测miR-146a-5p的靶标和相关的炎症途径。在体外，通过用热灭活的肺炎克雷伯菌（iKp）刺激MH-S细胞建立肺泡巨噬细胞炎症模型，然后进行QFLT处理。通过转染特异性抑制剂来抑制miR-146a-5p。使用qRT-PCR、蛋白质印迹法（WB）和其他方法评估QFLT对炎症反应、miR-146a-5p表达以及TLR4/MyD88/NF-κB信号传导的影响。
Kp感染显著加剧了肺部炎症，并下调了肺组织和MH-S细胞中miR-146a-5p的表达。QFLT治疗减轻了炎症反应并上调了miR-146a-5p的表达。生物信息学分析表明，miR-146a-5p靶向TRAF6，它是TLR4/MyD88/NF-κB途径的关键介质。蛋白质印迹分析进一步证实，QFLT降低了Kp诱导的MH-S细胞中TLR4/MyD88/NF-κB途径的上调。此外，抑制miR-146a-5p加剧了肺组织和MH-S细胞中的炎症反应，而QFLT治疗有效地减弱了这些炎症作用。此外，miR-146a-5p的抑制导致MH-S细胞中TLR4/MyD88/NF-κB信号通路中蛋白质表达升高，而给予QFLT显著降低了这些信号成分的表达水平。
这些发现表明，QFLT通过miR-146a-5p调节TLR4/MyD88/NF-κB轴来改善Kp诱导的肺炎。
