Gao Juan, Su Gang, Liu Jifei, Song Jinyang, Chen Wei, Chai Miao, Xie Xiaodong, Wang Manxia, Liu Junxi, Zhang Zhenchang
Department of Neurology, The Second Hospital & Clinical Medical School, Lanzhou University, Lanzhou, Gansu, China.
Institute of Genetics, School of Basic Medical Sciences, Lanzhou University, Lanzhou, Gansu, China.
CNS Neurosci Ther. 2024 Dec;30(12):e70158. doi: 10.1111/cns.70158.
Microglia/macrophages, as pivotal immune cells in the central nervous system (CNS), play a critical role in neuroinflammation associated with ischemic brain injury. Targeting their activation through pharmacological interventions represents a promising strategy to alleviate neurological deficits, thereby harboring significant implications for the prevention and treatment of ischemic stroke. Ligusticum cycloprolactam (LIGc), a novel monomeric derivative of traditional Chinese medicine, has shown potential as a therapeutic agent; however, its specific role in cerebral ischemic injury remains unclear.
In vitro experiments utilized lipopolysaccharide (LPS)-induced inflammation models of RAW264.7 cells and primary mouse microglia. In vivo studies employed LPS-induced neuroinflammation models in mice and a transient middle cerebral artery occlusion (tMCAO) mouse model to evaluate the impact of LIGc on neuroinflammation and microglia/macrophage phenotypic alterations. Further elucidation of the molecular mechanisms underlying these effects was achieved through RNA-Seq analyses.
LIGc exhibited the capacity to attenuate LPS-induced production of pro-inflammatory markers in macrophages and microglia, facilitating their transition to an anti-inflammatory phenotype. In models of LPS-induced neuroinflammation and tMCAO, LIGc ameliorated pathological behaviors and neurological deficits while mitigating brain inflammation. RNA-seq analyses revealed formyl peptide receptor 1 (FPR1) as a critical mediator of LIGc's effects. Specifically, FPR1 enhances the pro-inflammatory phenotype of microglia/macrophages and inhibits their anti-inflammatory response by upregulating NLR family pyrin domain protein 3 (NLRP3) inflammasomes, thus aggravating inflammatory processes. Conversely, LIGc exerts anti-inflammatory effects by downregulating the FPR1/NLRP3 signaling axis. Furthermore, FPR1 overexpression or NLRP3 agonists reversed the effects of LIGc observed in this study.
Our findings suggest that LIGc holds promise in improving ischemic brain injury and neuroinflammation through modulation of microglia/macrophage polarization. Mechanistically, LIGc attenuates the pro-inflammatory phenotype and promotes the anti-inflammatory phenotype by targeting the FPR1/NLRP3 signaling pathway, ultimately reducing inflammatory responses and mitigating neurological damage.
小胶质细胞/巨噬细胞作为中枢神经系统（CNS）中的关键免疫细胞，在与缺血性脑损伤相关的神经炎症中起关键作用。通过药物干预靶向其激活是减轻神经功能缺损的一种有前景的策略，因此对缺血性中风的预防和治疗具有重要意义。环丙内酯川芎嗪（LIGc）是一种新型的中药单体衍生物，已显示出作为治疗剂的潜力；然而，其在脑缺血损伤中的具体作用仍不清楚。
体外实验利用脂多糖（LPS）诱导的RAW264.7细胞和原代小鼠小胶质细胞炎症模型。体内研究采用LPS诱导的小鼠神经炎症模型和短暂性大脑中动脉闭塞（tMCAO）小鼠模型，以评估LIGc对神经炎症和小胶质细胞/巨噬细胞表型改变的影响。通过RNA测序分析进一步阐明这些作用的分子机制。
LIGc表现出减弱LPS诱导的巨噬细胞和小胶质细胞中促炎标志物产生的能力，促进它们向抗炎表型转变。在LPS诱导的神经炎症和tMCAO模型中，LIGc改善了病理行为和神经功能缺损，同时减轻了脑炎症。RNA测序分析显示甲酰肽受体1（FPR1）是LIGc作用的关键介质。具体而言，FPR1通过上调NLR家族含pyrin结构域蛋白3（NLRP3）炎性小体增强小胶质细胞/巨噬细胞的促炎表型并抑制其抗炎反应，从而加重炎症过程。相反，LIGc通过下调FPR1/NLRP3信号轴发挥抗炎作用。此外，FPR1过表达或NLRP3激动剂逆转了本研究中观察到的LIGc的作用。
我们的研究结果表明，LIGc有望通过调节小胶质细胞/巨噬细胞极化来改善缺血性脑损伤和神经炎症。机制上，LIGc通过靶向FPR1/NLRP3信号通路减弱促炎表型并促进抗炎表型，最终减少炎症反应并减轻神经损伤。
