Parkin Georgia M, Udawela Madhara, Gibbons Andrew, Dean Brian
Molecular Psychiatry Laboratory, the Florey Institute of Neuroscience and Mental Health, Parkville VIC 3052, Australia.
World J Psychiatry. 2018 Jun 28;8(2):51-63. doi: 10.5498/wjp.v8.i2.51.
Glutamate is the predominant excitatory neurotransmitter in the human brain and it has been shown that prolonged activation of the glutamatergic system leads to nerve damage and cell death. Following release from the pre-synaptic neuron and synaptic transmission, glutamate is either taken up into the pre-synaptic neuron or neighbouring glia by transmembrane glutamate transporters. Excitatory amino acid transporter (EAAT) 1 and EAAT2 are Na-dependant glutamate transporters expressed predominantly in glia cells of the central nervous system. As the most abundant glutamate transporters, their primary role is to modulate levels of glutamatergic excitability and prevent spill over of glutamate beyond the synapse. This role is facilitated through the binding and transportation of glutamate into astrocytes and microglia. The function of EAAT1 and EAAT2 is heavily regulated at the levels of gene expression, post-transcriptional splicing, glycosylation states and cell-surface trafficking of the protein. Both glutamatergic dysfunction and glial dysfunction have been proposed to be involved in psychiatric disorder. This review will present an overview of the roles that EAAT1 and EAAT2 play in modulating glutamatergic activity in the human brain, and mount an argument that these two transporters could be involved in the aetiologies of schizophrenia and affective disorders as well as represent potential drug targets for novel therapies for those disorders.
谷氨酸是人类大脑中主要的兴奋性神经递质,研究表明,谷氨酸能系统的长期激活会导致神经损伤和细胞死亡。从突触前神经元释放并经过突触传递后,谷氨酸要么通过跨膜谷氨酸转运体被摄取回突触前神经元,要么被摄取到邻近的神经胶质细胞中。兴奋性氨基酸转运体(EAAT)1和EAAT2是主要在中枢神经系统神经胶质细胞中表达的依赖钠的谷氨酸转运体。作为最丰富的谷氨酸转运体,它们的主要作用是调节谷氨酸能兴奋性水平,并防止谷氨酸扩散到突触之外。这一作用通过谷氨酸与星形胶质细胞和小胶质细胞的结合及转运来实现。EAAT1和EAAT2的功能在基因表达、转录后剪接、糖基化状态以及蛋白质的细胞表面运输等水平上受到严格调控。谷氨酸能功能障碍和神经胶质功能障碍均被认为与精神疾病有关。本综述将概述EAAT1和EAAT2在调节人类大脑谷氨酸能活性中所起的作用,并提出论点,即这两种转运体可能参与精神分裂症和情感障碍的病因学,并且是这些疾病新疗法的潜在药物靶点。