Reactive astrocytes induced by 2-chloroethanol modulate microglia polarization through IL-1β, TNF-α, and iNOS upregulation

Food Chem Toxicol. 2021 Nov:157:112550. doi: 10.1016/j.fct.2021.112550. Epub 2021 Sep 10.

Abstract

The synthetic organic chemical, 1,2-dichloroethane (1,2-DCE), can cause brain edemas under subacute poisoning. Our previous studies indicated that neuroinflammation could be induced due to astrocytes and microglia activation during brain edemas in 1,2-DCE-intoxicated mice. However, the crosstalk between these two glial cells in 1,2-DCE-induced neuroinflammation remained unclear. In this study, primary cultured rat astrocytes and microglia, as well as an immortalized microglia cell line were employed to study the effects of 2-chloroethanol (2-CE, a 1,2-DCE intermediate metabolite in vivo) treated astrocytes on microglia polarization. Our current results revealed that 2-CE treated rat astrocytes were activated through p38 mitogen-activated protein kinase (p38 MAPK)/nuclear factor-κB (NF-κB), and activator protein-1 (AP-1) signaling pathways. Theses pathways were triggered by reactive oxygen species (ROS) produced during 2-CE metabolism. Also, astrocytes were more sensitive to 2-CE effects than microglia. Interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS) expressions were upregulated in 2-CE-induced reactive astrocytes, enhancing IL-1β, TNF-α, and nitric oxide (NO) excretions, which stimulated microglia polarization. Therefore, the neuroinflammation induced by 1,2-DCE in mice's brains is probably triggered by reactive astrocytes.

Keywords: 1,2-Dichloroethane; 2-Chloroethanol; Microglia polarization; Reactive astrocytes.

MeSH terms

  • Animals
  • Astrocytes / drug effects*
  • Astrocytes / metabolism
  • Blotting, Western
  • Cell Polarity / drug effects
  • Ethylene Chlorohydrin / pharmacology*
  • Fluorescent Antibody Technique
  • Interleukin-1beta / metabolism*
  • Microglia / drug effects
  • Microglia / metabolism*
  • Nitric Oxide Synthase Type II / metabolism*
  • Rats
  • Rats, Wistar
  • Reactive Oxygen Species / metabolism
  • Real-Time Polymerase Chain Reaction
  • Signal Transduction / drug effects
  • Tumor Necrosis Factor-alpha / metabolism*
  • Up-Regulation / drug effects

Substances

  • Interleukin-1beta
  • Reactive Oxygen Species
  • Tumor Necrosis Factor-alpha
  • Ethylene Chlorohydrin
  • Nitric Oxide Synthase Type II