METHODS: Adult male C57BL/6 mice were subjected to ileocolic bowel resection (ICR) 24 h prior to permanent distant middle cerebral artery occlusion (dMCAO) to establish model PIS. White matter injury, functional outcomes, peripheral immune cell infiltration, and microglia phenotype were assessed up to 28 days after dMCAO using behavioral phenotyping, immunofluorescence staining, transmission electron microscopy, western blot, and FACS analysis.
RESULTS: We found surgery aggravated white matter injury and deteriorated sensorimotor deficits up to 28 days following PIS. The PIS mice exhibited significantly increased activation of peripheral and central CD8+ T cells, while significantly reduced numbers of mature oligodendrocytes compared to IS mice. Neutralizing CD8+ T cells partly reversed the aggravated demyelination following PIS. Pharmacological blockage or genetic deletion of receptor-interacting protein kinase 1 (RIPK1) activity could alleviate CD8+ T-cell infiltration and demyelination in PIS mice.
CONCLUSIONS: Surgery exacerbates demyelination and worsens neurological function by promoting infiltration of CD8+ T cells and microglia necroptosis, suggesting that modulating interactions of CD8+ T cells and microglia could be a novel therapeutic target of long-term neurological deficits of PIS.
方法:成年雄性C57BL/6小鼠在永久性远隔大脑中动脉闭塞(dMCAO)前24h进行回肠肠切除术(ICR),以建立PIS模型。白质损伤,功能结果,外周免疫细胞浸润,和小胶质细胞表型在dMCAO后28天使用行为表型进行评估,免疫荧光染色,透射电子显微镜,westernblot,和FACS分析。
结果:我们发现手术加重了白质损伤,并恶化了PIS后28天的感觉运动功能障碍。PIS小鼠表现出显著增加的外周和中枢CD8+T细胞的活化,与IS小鼠相比,成熟少突胶质细胞的数量显着减少。中和CD8+T细胞部分逆转了PIS后加重的脱髓鞘。受体相互作用蛋白激酶1(RIPK1)活性的药理阻断或基因缺失可以减轻PIS小鼠的CD8T细胞浸润和脱髓鞘。
结论:手术通过促进CD8+T细胞浸润和小胶质细胞坏死而加剧脱髓鞘和恶化神经功能,提示调节CD8+T细胞与小胶质细胞的相互作用可能是治疗PIS长期神经功能缺损的新靶点.