Jiménez-Torres Catya, El-Kehdy Hoda, Hernández-Kelly Luisa C, Sokal Etienne, Ortega Arturo, Najimi Mustapha
Laboratorio de Neurotoxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav-IPN), Departamento de Toxicología, Mexico City, Mexico.
Laboratory of Pediatric Hepatology and Cell Therapy, UCLouvain, Institut de Recherche Expérimentale et Clinique (IREC), Brussels, Belgium.
Front Neurosci. 2021 Jan 6;14:613225. doi: 10.3389/fnins.2020.613225. eCollection 2020.
Glutamate is the main excitatory amino acid acting at the level of pre and postsynaptic neurons, as well as in glial cells. It is involved in the coordinated modulation of energy metabolism, glutamine synthesis, and ammonia detoxification. The relationship between the functional status of liver and brain has been known for many years. The most widely recognized aspect of this relation is the brain dysfunction caused by acute liver injury that manifests a wide spectrum of neurologic and psychiatric abnormalities. Inflammation, circulating neurotoxins, and impaired neurotransmission have been reported in this pathophysiology. In the present contribution, we report the effect of a hepatotoxic compound like CCl on the expression of key proteins involved in glutamate uptake and metabolism as glutamate transporters and glutamine synthetase in mice liver, brain, and cerebellum. Our findings highlight a differential expression pattern of glutamate transporters in cerebellum. A significant Purkinje cells loss, in parallel to an up-regulation of glutamine synthetase, and astrogliosis in the brain have also been noticed. In the intoxicated liver, glutamate transporter 1 expression is up-regulated, in contrast to glutamine synthetase which is reduced in a time-dependent manner. Taken together our results demonstrate that the exposure to an acute CCl insult, leads to the disruption of glutamate transporters expression in the liver-brain axis and therefore a severe alteration in glutamate-mediated neurotransmission might be present in the central nervous system.
谷氨酸是作用于突触前和突触后神经元以及神经胶质细胞水平的主要兴奋性氨基酸。它参与能量代谢、谷氨酰胺合成和氨解毒的协调调节。肝脏和大脑功能状态之间的关系已为人所知多年。这种关系最广为人知的方面是急性肝损伤引起的脑功能障碍,表现为广泛的神经和精神异常。在这种病理生理学中,炎症、循环神经毒素和神经传递受损已有报道。在本论文中,我们报告了一种肝毒性化合物如四氯化碳(CCl)对参与谷氨酸摄取和代谢的关键蛋白质(如谷氨酸转运体和谷氨酰胺合成酶)在小鼠肝脏、大脑和小脑中表达的影响。我们的研究结果突出了谷氨酸转运体在小脑中的差异表达模式。还注意到大脑中浦肯野细胞显著丢失,同时谷氨酰胺合成酶上调以及星形胶质细胞增生。在中毒的肝脏中,谷氨酸转运体1的表达上调,而谷氨酰胺合成酶则呈时间依赖性降低。综合我们的结果表明,急性四氯化碳(CCl)损伤导致肝脑轴中谷氨酸转运体表达的破坏,因此中枢神经系统可能存在谷氨酸介导的神经传递的严重改变。