Sub-chronic administration of benzo[a]pyrene disrupts hippocampal long-term potentiation via inhibiting CaMK II/PKC/PKA-ERK-CREB signaling in rats

Environ Toxicol. 2020 Sep;35(9):961-970. doi: 10.1002/tox.22932. Epub 2020 Apr 7.

Abstract

Benzo[a]pyrene (B[a]P) is recognized as a neurotoxic pollutant to mammals, which could impair learning and memory function. Although there is some evidence to suggest that N-methyl-d-aspartate receptor (NMDAR), a glutamate receptor and ion channel protein in nerve cells, is involved into the B[a]P induced neurotoxicity, the exact molecular mechanisms remain to be elucidated, particularly the effects of B[a]P on the NMDAR downstream signaling transduction pathways. In the present study, we examined the neurotoxicity of sub-chronic administrated B[a]P on male Sprague-Dawley rats. Our data suggested that B[a]P exposure caused significant deficits in learning and memory function and the impairment of hippocampal LTP in rats. Further mechanistic studies indicate that B[a]P-induced learning and memory deficits are associated with the inhibition of NMDAR NR1 subunit transcription and protein phosphorylation. More importantly, the inactivation of CaMK II/PKC/PKA-ERK-CREB signaling pathways in hippocampus was detected at both the 2.5 and 6.25 mg/kg B[a]P-treated groups, indicating that multiple targets in NMDAR and downstream signaling pathways are involved in the B[a]P-induced neurotoxicity.

Keywords: benzo[a]pyrene; long-term potentiation; multiple targets; neurotoxicity.

MeSH terms

  • Animals
  • Benzo(a)pyrene / toxicity*
  • CA1 Region, Hippocampal / drug effects*
  • CA1 Region, Hippocampal / metabolism
  • Long-Term Potentiation / drug effects*
  • Male
  • Maze Learning / drug effects
  • Memory / drug effects
  • Neurons / drug effects
  • Neurons / metabolism
  • Phosphorylation
  • Protein Kinase C / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Glutamate / metabolism*
  • Receptors, N-Methyl-D-Aspartate / metabolism*
  • Signal Transduction / drug effects

Substances

  • Receptors, Glutamate
  • Receptors, N-Methyl-D-Aspartate
  • Benzo(a)pyrene
  • Protein Kinase C