Zhang Lulu, Feng Xiaoyu, An Hongsa, Yang Weifeng, Xia Yuwen, Wen Bo, Zheng Haoran, Chen Yihuan, Cheng Yungchi, Jiang Chunyan, Lu Cheng, Tan Yong
Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China.
Medical Experimental Center, China Academy of Chinese Medical Sciences, Beijing, China.
Front Pharmacol. 2025 May 30;16:1546652. doi: 10.3389/fphar.2025.1546652. eCollection 2025.
Community-associated methicillin-resistant (CA-MRSA) disrupts innate immunity by inducing necroptosis in polymorphonuclear neutrophils (PMNs), a process linked to excessive inflammation and tissue damage. CA-MRSA releases virulence factors that enhance its pathogenicity by disrupting the host's innate immune response, particularly impairing the phagocytic function of PMNs. Steamed Panax notoginseng (S-PN), a traditional Chinese medicine (TCM), has demonstrated immune-regulatory and anti-inflammatory properties, showing promising therapeutic effects in alleviating the severe inflammatory responses induced by pathogenic microbial infections.
This study aims to investigate the pharmacological effects and mechanisms of S-PN alleviating CA-MRSA-induced PMN necroptosis by suppressing MRSA virulence factors and inhibiting the RIPK1/RIPK3/MLKL signaling pathway, thereby attenuating inflammatory damage.
A co-culture model of MRSA USA300 strain and PMNs isolated from healthy human blood was established to observe the changes in necroptosis marker HMGB1, PMNs counts, ROS, chemokine MCP-1 and pro-inflammatory cytokines IL-1β, IL-8, TNF-α. RNA-seq was employed to analyze the effects of S-PN on the transcriptional expression of pathogenesis-related genes of MRSA. RT-PCR was utilized to validate the expression of S-PN on MRSA virulence factors and PMNs necroptosis related genes.
S-PN significantly inhibited HMGB1, ROS, MCP-1, IL-1β and IL-8 in MRSA-PMN co-cultures, the PMN count in the S-PN group was higher than that in the model group. S-PN downregulated MRSA pathogenic-associated infection and quorum sensing signaling pathways, and significantly reduced the virulence factors PSM and PVL. S-PN suppressed the expression of genes associated with necroptosis ripk1, ripk3, and mlkl in PMNs.
S-PN alleviates CA-MRSA infection-induced immune damage through dual mechanisms: suppression of bacterial virulence factors (PSM and PVL) and inhibition of PMNs necroptosis. These findings underscore its potential as a complementary therapeutic strategy against CA-MRSA infections, providing a theoretical foundation for integrating TCM into adjuvant treatments for drug-resistant bacterial infections.
社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）通过诱导多形核中性粒细胞（PMN）发生坏死性凋亡来破坏固有免疫，这一过程与过度炎症反应和组织损伤相关。CA-MRSA释放毒力因子，通过破坏宿主的固有免疫反应，特别是损害PMN的吞噬功能来增强其致病性。中药三七蒸制饮片（S-PN）具有免疫调节和抗炎特性，在减轻病原微生物感染引起的严重炎症反应方面显示出有前景的治疗效果。
本研究旨在探讨S-PN通过抑制MRSA毒力因子和抑制RIPK1/RIPK3/MLKL信号通路减轻CA-MRSA诱导的PMN坏死性凋亡的药理作用及机制，从而减轻炎症损伤。
建立MRSA USA300菌株与从健康人血液中分离的PMN的共培养模型，观察坏死性凋亡标志物HMGB1、PMN计数、活性氧（ROS）、趋化因子MCP-1以及促炎细胞因子IL-1β、IL-8、TNF-α的变化。采用RNA测序分析S-PN对MRSA致病相关基因转录表达的影响。利用逆转录聚合酶链反应（RT-PCR）验证S-PN对MRSA毒力因子和PMN坏死性凋亡相关基因表达的影响。
S-PN显著抑制MRSA-PMN共培养体系中的HMGB1、ROS、MCP-1、IL-1β和IL-8，S-PN组的PMN计数高于模型组。S-PN下调MRSA致病相关的感染和群体感应信号通路，并显著降低毒力因子PSM和PVL。S-PN抑制PMN中与坏死性凋亡相关的ripk1、ripk3和mlkl基因的表达。
S-PN通过双重机制减轻CA-MRSA感染诱导的免疫损伤：抑制细菌毒力因子（PSM和PVL）和抑制PMN坏死性凋亡。这些发现强调了其作为对抗CA-MRSA感染的补充治疗策略的潜力，为将中药纳入耐药细菌感染的辅助治疗提供了理论基础。
