1,2-Dichloroethane causes anxiety and cognitive dysfunction in mice by disturbing GABA metabolism and inhibiting the cAMP-PKA-CREB signaling pathway

Ecotoxicol Environ Saf. 2024 Jul 1:279:116464. doi: 10.1016/j.ecoenv.2024.116464. Epub 2024 May 17.

Abstract

1,2-Dichloroethane (1,2-DCE) is a powerfully toxic neurotoxin, which is a common environmental pollutant. Studies have indicated that 1,2-DCE long-term exposure can result in adverse effects. Nevertheless, the precise mechanism remains unknown. In this study, behavioral results revealed that 1,2-DCE long-term exposure could cause anxiety and learning and memory ability impairment in mice. The contents of γ-aminobutyric acid (GABA) and glutamine (Gln) in mice's prefrontal cortex decreased, whereas that of glutamate (Glu) increased. With the increase in dose, the activities of glutamate decarboxylase (GAD) decreased and those of GABA transaminase (GABA-T) increased. The protein and mRNA expressions of GABA transporter-3 (GAT-3), vesicular GABA transporter (VGAT), GABA A receptor α2 (GABAARα2), GABAARγ2, K-Cl cotransporter isoform 2 (KCC2), GABA B receptor 1 (GABABR1), GABABR2, protein kinase A (PKA), cAMP-response element binding protein (CREB), p-CREB, brain-derived neurotrophic factor (BDNF), c-fos, c-Jun and the protein of glutamate dehydrogenase (GDH) and PKA-C were decreased, while the expression levels of GABA transporter-1 (GAT-1) and Na-K-2Cl cotransporter isoform 1 (NKCC1) were increased. However, there was no significant change in the protein content of succinic semialdehyde dehydrogenase (SSADH). The expressions of adenylate cyclase (AC) and cyclic adenosine monophosphate (cAMP) contents were also reduced. In conclusion, the results of this study show that exposure to 1,2-DCE could lead to anxiety and cognitive impairment in mice, which may be related to the disturbance of GABA metabolism and its receptors along with the cAMP-PKA-CREB pathway.

Keywords: 1,2-Dichloroethane; Anxiety; Cognitive dysfunction; GABA metabolism; cAMP-PKA-CREB signaling pathway.

MeSH terms

  • Animals
  • Anxiety* / chemically induced
  • Cognitive Dysfunction / chemically induced
  • Cognitive Dysfunction / metabolism
  • Cyclic AMP / metabolism
  • Cyclic AMP Response Element-Binding Protein* / metabolism
  • Cyclic AMP-Dependent Protein Kinases* / metabolism
  • Environmental Pollutants / toxicity
  • Ethylene Dichlorides* / toxicity
  • GABA Plasma Membrane Transport Proteins / metabolism
  • Glutamate Decarboxylase / metabolism
  • Male
  • Mice
  • Signal Transduction* / drug effects
  • gamma-Aminobutyric Acid* / metabolism

Substances

  • gamma-Aminobutyric Acid
  • Cyclic AMP-Dependent Protein Kinases
  • Ethylene Dichlorides
  • Cyclic AMP Response Element-Binding Protein
  • ethylene dichloride
  • Cyclic AMP
  • Environmental Pollutants
  • GABA Plasma Membrane Transport Proteins
  • Glutamate Decarboxylase