Garcia Israel José Pereira, Kinoshita Paula Fernanda, Valadares Jéssica Martins de Moura, Carvalho Luciana Estefani Drumond de, Cortes Vanessa Faria, Barbosa Leandro Augusto, Scavone Cristoforo, Santos Hérica de Lima
Cellular Biochemistry Laboratory, Federal University of São João del-Rei, Campus Cento-Oeste, Divinópolis 35501-296, Brazil.
Membrane and ATPase Biochemistry Laboratory, Federal University of São João del-Rei, Campus Cento-Oeste, Divinópolis 35501-296, Brazil.
Biomedicines. 2023 Mar 16;11(3):920. doi: 10.3390/biomedicines11030920.
A lipopolysaccharide (LPS)-induced neuroinflammation rat model was used to study the effects of ouabain (OUA) at low concentrations, which can interact with the Na,K-ATPase, causing the modulation of intracellular signalling pathways in the Central Nervous System. Our study aimed to analyse the effects of OUA on glutamate transport in the hippocampus of rats with LPS-induced neuroinflammation. Adult male Wistar rats were divided into four groups: OUA (1.8 µg/kg), saline (CTR), LPS (200 µg/kg), and OUA + LPS (OUA 20 min before LPS). The animals were sacrificed after 2 h, and the hippocampus was collected for analysis. After treatment, we determined the activities of Na,K-ATPase and glutamine synthetase (GS). In addition, expression of the α1, α2, and α3 isoforms of Na,K-ATPase and the glutamate transporters, EAAT1 and EAAT2, were also analysed. Treatment with OUA caused a specific increase in the α2 isoform expression (20%), whereas LPS decreased its expression (22%), and treatment with OUA before LPS prevented the effects of LPS. Moreover, LPS caused a decrease of approximately 50% in GS activity compared with that in the CTR group; however, OUA pre-treatment attenuated this effect of LPS. Notably, it was found that treatment with OUA caused an increase in the expression of EAAT1 (30%) and EAAT2 (25%), whereas LPS caused a decrease in the expression of EAAT1 (23%) and EAAT2 (25%) compared with that in the CTR group. When treated with OUA, the effects of LPS were abrogated. In conclusion, the OUA pre-treatment abolished the effect caused by LPS, suggesting that this finding may be related to the restoration of the interaction between FXYD2 and the studied membrane proteins.
采用脂多糖（LPS）诱导的神经炎症大鼠模型，研究低浓度哇巴因（OUA）的作用，其可与钠钾ATP酶相互作用，引起中枢神经系统细胞内信号通路的调节。本研究旨在分析OUA对LPS诱导的神经炎症大鼠海马中谷氨酸转运的影响。成年雄性Wistar大鼠分为四组：OUA（1.8μg/kg）、生理盐水（CTR）、LPS（200μg/kg）和OUA+LPS（LPS注射前20分钟注射OUA）。2小时后处死动物，取海马进行分析。处理后，测定钠钾ATP酶和谷氨酰胺合成酶（GS）的活性。此外，还分析了钠钾ATP酶α1、α2和α3亚型以及谷氨酸转运体EAAT1和EAAT2的表达。OUA处理导致α2亚型表达特异性增加（约20%），而LPS使其表达降低（约22%），LPS注射前用OUA处理可防止LPS的这种作用。此外，与CTR组相比，LPS使GS活性降低约50%；然而，OUA预处理减弱了LPS的这种作用。值得注意的是，发现OUA处理导致EAAT1表达增加（约30%）和EAAT2表达增加（约25%），而与CTR组相比，LPS导致EAAT1表达降低（约23%）和EAAT2表达降低（约25%）。用OUA处理后，LPS的作用被消除。总之，OUA预处理消除了LPS引起的作用，表明这一发现可能与FXYD2与所研究膜蛋白之间相互作用的恢复有关。
