Department of Neurology, the First Affiliated Hospital of Zhengzhou University, No.1 Eastern Jianshe Road, Zhengzhou 450052, Henan, China; The Henan Key Laboratory of Cerebrovascular Disease, Zhengzhou University, No.1 Eastern Jianshe Road, Zhengzhou 450052, Henan, China.
The Henan Key Laboratory of Cerebrovascular Disease, Zhengzhou University, No.1 Eastern Jianshe Road, Zhengzhou 450052, Henan, China; Zhengzhou University, No.1 Eastern Jianshe Road, Zhengzhou 450052, Henan, China.
Exp Neurol. 2020 Jun;328:113233. doi: 10.1016/j.expneurol.2020.113233. Epub 2020 Feb 7.
Interleukin-33 (IL-33) is known to activate the regulatory T lymphocytes (Tregs), which are negatively correlated with brain damage after ischemic stroke. In this study, we aimed to investigate the role of Tregs in IL-33-mediated neuroprotection and elucidate the underlying mechanisms. In vivo, male C57BL/6 N mice were subjected to 60 min of transient middle cerebral artery occlusion (tMCAO), followed by daily administration of vehicle or IL-33 immediately after injury. Tregs were depleted by intraperitoneal administration of anti-CD25 antibody (anti-CD25Ab). Behavioral changes, brain edema, neuronal injury, Treg percentages, and cytokine expression levels were investigated in each group. In vitro experiments, primary mouse neuronal cells were subjected to oxygen-glucose deprivation (OGD) for 3 h. Vehicle- or drug-conditioned Tregs were applied to the neurons at the time of induction of hypoxia. Neuronal apoptosis and cytokine expression were measured in each group. The results indicate that intraperitoneal administration of anti-CD25Ab reduced CD4 + CD25 + Foxp3+ Tregs, increased infarct volume, enhanced stroke-induced cell death, and decreased sensorimotor functions. Notably, IL-33 increased CD4 + CD25 + Foxp3+ Tregs in the spleen and brain. However, blockading ST2 attenuated these effects of IL-33. The supernatant of the IL-33-treated Treg culture reduced neuronal apoptosis and elevated the production of the Treg cytokines IL-10, IL-35, and transforming growth factor-β (TGF-β). Anti-CD25Ab abrogated the neuroprotective effect of IL-33. Mechanistically, the neuroprotective effects of IL-33 were associated with reduction in apoptosis-related proteins and production of Tregs related cytokines. Overall, these findings showed that IL-33 afforded neuroprotection against ischemic brain injury by enhancing ST2-dependent regulatory T-cell expansion and activation via a mechanism involving anti-apoptosis proteins and cytokines, representing a promising immune modulatory target for the treatment of stroke.
白细胞介素 33（IL-33）已知可激活调节性 T 淋巴细胞（Tregs），后者与缺血性脑卒中后的脑损伤呈负相关。在本研究中，我们旨在探究 Tregs 在 IL-33 介导的神经保护中的作用，并阐明其潜在机制。在体内，雄性 C57BL/6N 小鼠接受 60 分钟短暂性大脑中动脉闭塞（tMCAO），随后在损伤后立即每天给予载体或 IL-33。通过腹腔内给予抗 CD25 抗体（抗 CD25Ab）耗竭 Tregs。在各组中检测行为变化、脑水肿、神经元损伤、Treg 百分比和细胞因子表达水平。在体外实验中，原代小鼠神经元细胞在缺氧诱导前经历氧葡萄糖剥夺（OGD）3 小时。在诱导缺氧时，将载体或药物处理的 Tregs 应用于神经元。在各组中测量神经元凋亡和细胞因子表达。结果表明，腹腔内给予抗 CD25Ab 减少了 CD4+CD25+Foxp3+Tregs，增加了梗死体积，增强了卒中诱导的细胞死亡，并降低了感觉运动功能。值得注意的是，IL-33 增加了脾脏和大脑中的 CD4+CD25+Foxp3+Tregs。然而，阻断 ST2 减弱了 IL-33 的这些作用。IL-33 处理的 Treg 培养物的上清液减少了神经元凋亡并增加了 Treg 细胞因子 IL-10、IL-35 和转化生长因子-β（TGF-β）的产生。抗 CD25Ab 阻断了 IL-33 的神经保护作用。从机制上讲，IL-33 的神经保护作用与凋亡相关蛋白的减少和 Tregs 相关细胞因子的产生有关。总体而言，这些发现表明，IL-33 通过增强 ST2 依赖性调节性 T 细胞扩增和激活来提供对缺血性脑损伤的神经保护作用，其机制涉及抗凋亡蛋白和细胞因子，代表了治疗中风的有前途的免疫调节靶点。
