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Updated: Jun 1, 2026
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Published on: August 7, 2013
Arsenite exposure downregulates EAAT1/GLAST transporter expression in glial cells
Yaneth Castro-Coronel1, Luz María Del Razo, Miriam Huerta
1Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México, D.F. México.
Summary
Chronic arsenic exposure damages the central nervous system (CNS). This study shows inorganic arsenic targets the excitatory amino acid transporter 1 (EAAT1/GLAST) in glial cells, impairing glutamate transport.
Area of Science:
- Neuroscience
- Toxicology
- Cell Biology
Background:
- Chronic inorganic arsenic exposure causes central nervous system (CNS) damage.
- Glutamate (GLU) excitotoxicity occurs when synaptic GLU levels are not regulated by excitatory amino acid transporters.
- Excitatory amino acid transporter 1 (EAAT1/GLAST) in Bergmann glia mediates over 90% of cerebellar GLU uptake.
Purpose of the Study:
- To investigate if EAAT1/GLAST is a molecular target of arsenite.
- To understand the molecular mechanisms underlying arsenite-induced neurotoxicity in glial cells.
Main Methods:
- Primary cultures of chick cerebellar Bergmann glial cells were exposed to sodium arsenite.
- EAAT1/GLAST activity was assessed using ³H-D-aspartate uptake assays.
- Kinetic studies, transcriptional analysis, and investigation of reactive oxidative species and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) activity were performed.
Main Results:
- Arsenite exposure significantly decreased GLU transport by EAAT1/GLAST.
- Kinetic analysis revealed decreases in K(M) and V(max) values, linked to protein kinase A, protein kinase C, and p38 MAPK signaling.
- Diminished chglast transcription was observed, alongside increased Nrf2 DNA-binding activity and glutathione levels, without evidence of oxidative or lipid peroxidative damage.
Conclusions:
- EAAT1/GLAST is identified as a molecular target of arsenite.
- Glial cell dysfunction, specifically impaired EAAT1/GLAST function, plays a critical role in arsenite-induced neurotoxicity.
- These findings highlight the importance of glial cells in maintaining brain function and their susceptibility to toxic insults.
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