Department of Emergency, The 940th Hospital of Joint Logistics Support force of Chinese People's Liberation Army, Lanzhou, Gansu, China.
Department of Oral Medicine, Lanzhou University Dental Hospital, Lanzhou, Gansu, China.
Brain Behav. 2022 Sep;12(9):e2687. doi: 10.1002/brb3.2687. Epub 2022 Aug 11.
Subarachnoid hemorrhage (SAH) is a severe acute neurological disorder. SAH causes neuroinflammation and leads to early brain injury (EBI) and secondary injury. MicroRNAs are crucial regulators in a variety of neurological diseases. This study was performed to decipher how miR-340-5p functions in SAH.
An experimental mouse model with SAH was established by the intravascular perforation, and the in vitro SAH model was constructed by exposing cocultured primary neurons and microglia to oxyhemoglobin. After overexpression of miR-340-5p in mice, the neurobehavioral disorders were evaluated by Garcia test; brain edema was evaluated by wet-dry method; blood-brain barrier (BBB) damage was detected with Evan's blue staining; levels of inflammatory cytokines were detected with enzyme-linked immunosorbent assay. After miR-340-5p was transfected in to microglia, Iba-1 expression was detected by Western blot, and neuronal apoptosis were detected with flow cytometry. The targeting relationship between miR-340-5p and STING was verified by dual-luciferase reporter gene assay and RNA immunoprecipitation assay.
MiR-340-5p was significantly inhibited in the brain tissues of mice with SAH and microglia of SAH model, and neurological impairment, brain edema, BBB injury, and neuroinflammation were significantly alleviated in mice after overexpressing miR-340-5p. STING was identified as a target of miR-340-5p, and STING overexpression could counteract the effects of miR-340-5p overexpression on neurons.
MiR-340-5p can attenuate EBI caused by SAH-induced neuroinflammation by inhibiting STING.
蛛网膜下腔出血（SAH）是一种严重的急性神经系统疾病。SAH 引起神经炎症，导致早期脑损伤（EBI）和继发性损伤。microRNAs 是多种神经疾病的重要调节因子。本研究旨在阐明 miR-340-5p 在 SAH 中的作用机制。
通过血管内穿孔建立 SAH 实验小鼠模型，通过暴露共培养的原代神经元和小胶质细胞于氧合血红蛋白构建体外 SAH 模型。在小鼠中过表达 miR-340-5p 后，通过 Garcia 测试评估神经行为障碍；通过干湿法评估脑水肿；通过 Evan's 蓝染色检测血脑屏障（BBB）损伤；通过酶联免疫吸附试验检测炎症细胞因子水平。转染 miR-340-5p 后，通过 Western blot 检测小胶质细胞中 Iba-1 的表达，通过流式细胞术检测神经元凋亡。通过双荧光素酶报告基因检测和 RNA 免疫沉淀实验验证 miR-340-5p 与 STING 的靶向关系。
SAH 小鼠脑组织和 SAH 模型小胶质细胞中 miR-340-5p 表达显著下调，过表达 miR-340-5p 可显著减轻 SAH 小鼠的神经功能损伤、脑水肿、BBB 损伤和神经炎症。STING 被鉴定为 miR-340-5p 的靶基因，过表达 STING 可拮抗 miR-340-5p 过表达对神经元的作用。
miR-340-5p 通过抑制 STING 减轻由 SAH 引起的神经炎症导致的 EBI。
