Zhang Mengmeng, Guo Bingnan, Zhang Xiaowei, Han Dong, Lv Lanxin, Yan Xiaoqing, Su Chenglei, Chai Dafei, Zhao Ningjun, Yan Xianliang, Hu Shuqun
Department of Emergency Medicine, the Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, 221002, Jiangsu, China.
The Laboratory of Emergency Medicine, School of Second Clinical Medicine, Xuzhou Medical University, Xuzhou, 221002, Jiangsu, China.
J Neuroinflammation. 2025 Jun 25;22(1):164. doi: 10.1186/s12974-025-03492-6.
Acute ischemic stroke is a disastrous disease characterized by damaging blood flow in the brain, leading to acute brain injury. Acute brain ischemia elicits severe inflammation, thus in turn, aggravates neural injury. Interferon-Induced Protein 35 (IFP35), is a 35 kDa protein, a novel type of DAMP that trigger inflammatory responses, exacerbating acute and chronic inflammatory disease. This study aimed to investigate the potential neuroinflammation role of IFP35 in acute ischemic stroke in a mouse model of MCAO.
C57BL/6 male mice were subjected to middle cerebral artery occlusion (MCAO) to establish an animal model of acute ischemic stroke. Leveraging serum from stroke patients, serum and brain tissue after MCAO mice, IFP35 was released. Immunofluorescence assay was used to investigated the cell sources of IFP35 expression after MCAO. The impact of IFP35 on neuroinflammation and neural injury was assessed by siRNA-mediated cerebral IFP35 knockdown. Behavioral tests, and brain tissues were harvested for histological analysis and biochemical assays. TUNEL assays were used to evaluate neuronal damage. TTC staining was performed to assess infarction volumes. Additionally, using western blotting and immunofluorescence assays, we further assessed the contribution of TLR4/NF-κB/NLRP3 signaling in MCAO mice and BV2 cells.
IFP35 was accumulated in peripheral blood of cerebral ischaemia patients, ischemia mice serum, as well as peri-infarct regions in focal cerebral ischemia mice. Although endothelial cells, microglia, and astrocytes are capable of expressing IFP35, cerebral neural cells seem to express and release more IFP35 compare to other cell types. Knockdown of IFP35 alleviated the production of neuroinflammatory cytokines, decreased neuronal death, and minimized infarct volumes, ultimately leading to improved neurological outcomes. Importantly, IFP35 triggered the activation of NF-κΒ and NLRP3 signaling, exacerbating neuroinflammation and brain injury by binding its receptor TLR4.
This study revealed IFP35 as a novel DAMP released during cerebral ischemia that promotes neuroinflammation and injury, expanding the current understanding of inflammatory networks following stroke.
急性缺血性中风是一种灾难性疾病，其特征是脑部血流受损，导致急性脑损伤。急性脑缺血引发严重炎症，进而加重神经损伤。干扰素诱导蛋白35（IFP35）是一种35 kDa的蛋白质，是一种新型的可触发炎症反应、加剧急性和慢性炎症性疾病的内源性危险信号分子。本研究旨在探讨IFP35在大脑中动脉闭塞（MCAO）小鼠模型的急性缺血性中风中潜在的神经炎症作用。
将C57BL/6雄性小鼠进行大脑中动脉闭塞（MCAO）以建立急性缺血性中风动物模型。利用中风患者的血清、MCAO小鼠的血清和脑组织释放IFP35。采用免疫荧光法研究MCAO后IFP35表达的细胞来源。通过小干扰RNA（siRNA）介导的脑内IFP35敲低来评估IFP35对神经炎症和神经损伤的影响。进行行为测试，并收集脑组织进行组织学分析和生化检测。采用TUNEL法评估神经元损伤。进行TTC染色以评估梗死体积。此外，通过蛋白质免疫印迹法和免疫荧光法，我们进一步评估了TLR4/NF-κB/NLRP3信号通路在MCAO小鼠和BV2细胞中的作用。
IFP35在脑缺血患者的外周血、缺血小鼠血清以及局灶性脑缺血小鼠的梗死周围区域中蓄积。尽管内皮细胞、小胶质细胞和星形胶质细胞都能够表达IFP35，但与其他细胞类型相比，脑神经元细胞似乎表达和释放更多的IFP35。敲低IFP35可减轻神经炎症细胞因子的产生，减少神经元死亡，并使梗死体积最小化，最终改善神经功能结局。重要的是，IFP35通过结合其受体TLR4触发NF-κB和NLRP3信号通路的激活，加剧神经炎症和脑损伤。
本研究揭示IFP35是脑缺血期间释放的一种新型内源性危险信号分子，可促进神经炎症和损伤，扩展了目前对中风后炎症网络的认识。
