Skórkowska Alicja, Krzyżanowska Weronika, Bystrowska Beata, Torregrossa Roberta, Whiteman Matthew, Pomierny Bartosz, Budziszewska Bogusława
Jagiellonian University Medical College, Department of Toxicological Biochemistry, Chair of Toxicology, Medyczna 9, 30-688 Kraków, Poland.
St. Luke's Campus, University of Exeter Medical School, EX1 2LU Exeter, United Kingdom.
Neuroscience. 2024 Feb 16;539:86-102. doi: 10.1016/j.neuroscience.2023.11.008. Epub 2023 Nov 20.
The vast majority of stroke cases are classified as ischemic stroke, but effective pharmacotherapy strategies to treat brain infarction are still limited. Glutamate, which is a primary mediator of excitotoxicity, contributes to neuronal damage in numerous pathologies, including ischemia. The aim of this study was to investigate the effect of the hydrogen sulfide donor AP39 on excitotoxicity. AP39 was administered as a single dose of 100 nmol/kg b.w. i.v. 10 min after the restoration of blood flow and 100 min after middle cerebral artery occlusion (MCAO) in male Sprague-Dawley rats. Neurological deficits by Phillips's score, and infarct volume by TTC staining were evaluated (n = 8). LC-MS was used to determine the extracellular glutamate concentration in microdialysates collected intrasurgically and from freely moving animals 24 h and 3 days after reperfusion (n = 6). The expression of proteins involved in the regulation of glutamatergic transmission was investigated 24 h after reperfusion by Western-blot analysis (n = 6). The results were verified by double-immunostaining of brain cryosections (n = 6). The results showed a significant longitudinal decrease in extracellular glutamate concentrations in the motor cortex and hippocampus in MCAO + AP39 rats compared to MCAO rats. Moreover, the administration of AP39 increased the content of the GLT-1 transporter and reduced the content of VGLUT1 in the ischemic core. Upregulation of the GLT-1 transporter responsible for glutamate reuptake from the synaptic cleft, and downregulation of VGLUT1, which regulates glutamate transport to synaptic vesicles, indicate that these are important mechanisms by which AP39 reduces extracellular glutamate concentrations and, consequently, excitotoxicity after ischemia.
绝大多数中风病例被归类为缺血性中风，但治疗脑梗死的有效药物治疗策略仍然有限。谷氨酸是兴奋性毒性的主要介质，在包括缺血在内的多种病理过程中导致神经元损伤。本研究的目的是探讨硫化氢供体AP39对兴奋性毒性的影响。在雄性Sprague-Dawley大鼠中，于血流恢复后10分钟和大脑中动脉闭塞（MCAO）后100分钟静脉注射单剂量100 nmol/kg体重的AP39。通过菲利普斯评分评估神经功能缺损，通过TTC染色评估梗死体积（n = 8）。使用液相色谱-质谱联用（LC-MS）测定手术中及再灌注后24小时和3天从自由活动动物收集的微透析液中的细胞外谷氨酸浓度（n = 6）。通过蛋白质印迹分析在再灌注后24小时研究参与谷氨酸能传递调节的蛋白质表达（n = 6）。通过脑冷冻切片的双重免疫染色验证结果（n = 6）。结果显示，与MCAO大鼠相比，MCAO + AP39大鼠运动皮层和海马中的细胞外谷氨酸浓度显著纵向降低。此外，AP39的给药增加了缺血核心区GLT-1转运体的含量并降低了VGLUT1的含量。负责从突触间隙重新摄取谷氨酸的GLT-1转运体的上调以及调节谷氨酸向突触小泡转运的VGLUT1的下调表明，这些是AP39降低细胞外谷氨酸浓度并因此降低缺血后兴奋性毒性的重要机制。
