黄芩素通过抑制ALOX15介导的M2巨噬细胞功能减轻嗜酸性鼻窦炎

文献信息

中文摘要

嗜酸性慢性鼻窦炎伴鼻息肉（eCRSwNP）以2型炎症为特征，包括M2巨噬细胞浸润。黄芩素是一种具有抗炎特性的黄酮类化合物。本研究旨在探讨黄芩素在木瓜蛋白酶诱导的嗜酸性鼻窦炎模型中的治疗作用，并确定其是否通过花生四烯酸15-脂氧合酶（ALOX15）依赖的M2巨噬细胞功能发挥作用。分析对照组、非嗜酸性CRSwNP（neCRSwNP）和eCRSwNP的临床鼻样本中ALOX15的表达和定位。将THP-1细胞分化并极化为M2巨噬细胞，检测黄芩素对ALOX15表达、脂质过氧化、细胞因子分泌和转录组谱的影响。使用ALOX15抑制剂PD146176进行靶点验证。通过鼻内滴注木瓜蛋白酶建立小鼠嗜酸性鼻窦炎模型，随后给予黄芩素治疗。评估黏膜炎症、IgE水平、蛋白聚糖2（PRG2）/ALOX15表达和免疫细胞浸润。ALOX15在eCRSwNP组织中上调，并定位于CD68+CD206+ M2巨噬细胞。体外实验中，M2极化增加了ALOX15表达和脂质过氧化。黄芩素抑制了ALOX15表达、脂质过氧化以及CCL22、CCL2、CXCL12、FGF-2和IL-15的分泌。PD146176产生类似效果，且在ALOX15阻断后黄芩素未显示额外作用。RNA测序显示黄芩素处理后M2巨噬细胞发生转录重塑。体内实验中，木瓜蛋白酶增加了筛窦黏膜增厚、血清IgE、PRG2/ALOX15阳性细胞以及CD45+免疫细胞、CD170+嗜酸性粒细胞、F4/80+巨噬细胞和B220+ B细胞的浸润。黄芩素显著减轻了所有这些病理变化。总之，黄芩素通过抑制脂质过氧化和ALOX15相关的M2巨噬细胞分泌功能，减轻木瓜蛋白酶诱导的eCRSwNP样炎症。ALOX15/M2巨噬细胞轴可能是eCRSwNP的潜在治疗靶点。

英文摘要

Eosinophilic chronic rhinosinusitis with nasal polyps (eCRSwNP) is characterized by type 2 inflammation, including M2 macrophage infiltration. Baicalein is a flavonoid with anti-inflammatory properties. This study aimed to investigate the therapeutic effect of baicalein in a papain-induced eosinophilic rhinosinusitis model and to determine whether it acts through arachidonate 15-lipoxygenase (ALOX15)-dependent M2 macrophage function. Clinical nasal samples from controls, non-eosinophilic CRSwNP (neCRSwNP), and eCRSwNP were analyzed for ALOX15 expression and localization. THP-1 cells were differentiated and polarized toward M2 macrophages, and the effects of baicalein on ALOX15 expression, lipid peroxidation, cytokine secretion, and transcriptomic profile were examined. The ALOX15 inhibitor PD146176 was used for target validation. A murine eosinophilic rhinosinusitis model was established by intranasal papain instillation, followed by baicalein treatment. Mucosal inflammation, IgE levels, proteoglycan 2 (PRG2)/ALOX15 expression, and immune cell infiltration were evaluated. ALOX15 was upregulated in eCRSwNP tissues and localized to CD68+CD206+ M2 macrophages. In vitro, M2 polarization increased ALOX15 expression and lipid peroxidation. Baicalein suppressed ALOX15 expression, lipid peroxidation, and the secretion of CCL22, CCL2, CXCL12, FGF-2, and IL-15. PD146176 produced similar effects, and baicalein showed no additional effect after ALOX15 blockade. RNA sequencing revealed transcriptional remodeling in M2 macrophages after baicalein treatment. In vivo, papain increased ethmoid sinus mucosal thickening, serum IgE, PRG2/ALOX15 positive cells, and infiltration of CD45+ immune cells, CD170+ eosinophils, F4/80+ macrophages, and B220+ B cells. Baicalein significantly alleviated all these pathological changes. In conclusion, baicalein attenuates papain-induced eCRSwNP-like inflammation by inhibiting lipid peroxidation and ALOX15-associated M2 macrophage secretory function. The ALOX15/M2 macrophage axis may represent a potential therapeutic target for eCRSwNP.