Previous studies have indicated that particulate matter 2.5 (PM2.5) exposure stimulates systemic inflammation and activates the hypothalamus–pituitary–adrenal (HPA) axis, both of which are associated with stroke incidence and mortality. However, whether filtered air (FA) intervention modulates inflammation and HPA axis activation is still largely unknown. For FA group and PM2.5 group, adult Sprague-Dawley male and female rats were exposed to FA or PM2.5 for 6 months, respectively. For PM2.5 + 15 days FA group, the rats were achieved by receiving 15 days FA after PM2.5 exposure for 6 months. The immune cells and inflammatory biomarker levels in the blood and brain were analyzed by flow cytometry, ELISA, and qRT-PCR. To assess HPA axis activation, the levels of hormones in the blood were also analyzed by ELISA. FA intervention increased the percentage of CD4 T cells and T cells in the blood, which had decreased after PM2.5 exposure in both male and female rats. The ELISA and qRT-PCR results showed that FA intervention significantly reduced the levels of inflammatory biomarkers in the peripheral blood, and alleviated neuroinflammation in the cortex, hippocampus, and striatum. In addition, FA intervention also inhibited the inflammation in the hypothalamus and pituitary and adrenal glands, and decreased the levels of HPA axis hormones. Our results indicate that FA intervention exerts a protective effect on the brain by decreasing inflammation and HPA axis activation after PM2.5 exposure in both male and female rats.

先前的研究表明，颗粒物 2.5 (PM2.5) 暴露会刺激全身炎症并激活下丘脑 - 垂体 - 肾上腺 (HPA) 轴，这两者都与中风发病率和死亡率有关。然而，过滤空气 (FA) 干预是否会调节炎症和 HPA 轴激活仍然在很大程度上未知。对于 FA 组和 PM2.5 组，成年 Sprague-Dawley 雄性和雌性大鼠分别接触 FA 或 PM2.5 6 个月。PM2.5+15天FA组，大鼠在PM2.5暴露6个月后接受15天FA。通过流式细胞术、ELISA 和 qRT-PCR 分析血液和大脑中的免疫细胞和炎症生物标志物水平。为了评估 HPA 轴的激活，还通过 ELISA 分析了血液中的激素水平。FA 干预增加了血液中 CD4 T 细胞和 T 细胞的百分比，在雄性和雌性大鼠暴露于 PM2.5 后，该百分比均有所下降。ELISA和qRT-PCR结果显示FA干预显着降低外周血炎症生物标志物水平，减轻皮层、海马和纹状体的神经炎症。此外，FA干预还抑制了下丘脑、垂体和肾上腺的炎症，降低了HPA轴激素水平。我们的结果表明，FA 干预通过减少雄性和雌性大鼠在 PM2.5 暴露后的炎症和 HPA 轴激活对大脑产生保护作用。ELISA和qRT-PCR结果显示FA干预显着降低外周血炎症生物标志物水平，减轻皮层、海马和纹状体的神经炎症。此外，FA干预还抑制了下丘脑、垂体和肾上腺的炎症，降低了HPA轴激素水平。我们的结果表明，FA 干预通过减少雄性和雌性大鼠在 PM2.5 暴露后的炎症和 HPA 轴激活对大脑产生保护作用。ELISA和qRT-PCR结果显示FA干预显着降低外周血炎症生物标志物水平，减轻皮层、海马和纹状体的神经炎症。此外，FA干预还抑制了下丘脑、垂体和肾上腺的炎症，降低了HPA轴激素水平。我们的结果表明，FA 干预通过减少雄性和雌性大鼠在 PM2.5 暴露后的炎症和 HPA 轴激活对大脑产生保护作用。FA干预还抑制了下丘脑、垂体和肾上腺的炎症，并降低了HPA轴激素的水平。我们的结果表明，FA 干预通过减少雄性和雌性大鼠在 PM2.5 暴露后的炎症和 HPA 轴激活对大脑产生保护作用。FA干预还抑制了下丘脑、垂体和肾上腺的炎症，并降低了HPA轴激素的水平。我们的结果表明，FA 干预通过减少雄性和雌性大鼠在 PM2.5 暴露后的炎症和 HPA 轴激活对大脑产生保护作用。