Ligand-independent activation of AhR by hydroquinone mediates benzene-induced hematopoietic toxicity

Chem Biol Interact. 2022 Mar 1:355:109845. doi: 10.1016/j.cbi.2022.109845. Epub 2022 Feb 4.

Abstract

Although it has been well recognized that benzene exposure can cause hematopoietic disorders such as aplastic anemia and leukemia, the underlying molecular mechanism remains to be fully understood. Emerging evidence indicated that aryl hydrocarbon receptor (AhR) plays important roles in hematopoietic and immune systems. This study investigated the activation of aryl hydrocarbon receptor (AhR) by hydroquinone (HQ) and its role in HQ-induced DNA damage and apoptosis in cultured human lymphocytes (JHP cells). We also investigated the effect of ROS on AhR activation and functions in JHP cells exposed to HQ with and without regulator including N-acetyl-l-cysteine (NAC), a potent antioxidant, and tert-butylhydroquinone (TBHQ), a Nrf2 activator. Results showed that HQ can cause oxidative stress, DNA damage and apoptosis. Pretreatment of an AhR antagonist (CH223191) can significantly increase the cell survival and mitigate HQ-induced toxicities such as DNA damage and apoptosis. We found that HQ can obviously increase expressions of total protein of AhR and prompt nuclear translocation compared to the control group. Interestingly, NAC can block HQ-induced AhR activation and DNA damage and apoptosis. Conclusively, our results indicated that HQ toxicity is mediated by AhR which is in turn regulated by ROS generated by HQ. The interaction between AhR and ROS drive and amplify the hematopoietic toxicity of HQ. This study provided new insights of mechanism and potential targets for the prevention and treatment to benzene-induced hematopoietic toxicity.

Keywords: Apoptosis; Aromatic hydrocarbon receptor; DNA damage; Hydroquinone; Reactive oxygen species.

MeSH terms

  • Acetylcysteine / pharmacology
  • Apoptosis / drug effects
  • Basic Helix-Loop-Helix Transcription Factors / chemistry
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Benzene / toxicity
  • Cell Line
  • Cell Survival / drug effects
  • Cytochrome P-450 CYP1A1 / genetics
  • Cytochrome P-450 CYP1A1 / metabolism
  • DNA Damage / drug effects
  • HSP90 Heat-Shock Proteins / genetics
  • HSP90 Heat-Shock Proteins / metabolism
  • Humans
  • Hydroquinones / pharmacology*
  • Ligands*
  • Lymphocytes / cytology
  • Lymphocytes / metabolism
  • NF-E2-Related Factor 2 / metabolism
  • Oxidative Stress / drug effects*
  • Reactive Oxygen Species / metabolism
  • Receptors, Aryl Hydrocarbon / chemistry
  • Receptors, Aryl Hydrocarbon / genetics
  • Receptors, Aryl Hydrocarbon / metabolism*

Substances

  • AHR protein, human
  • Basic Helix-Loop-Helix Transcription Factors
  • HSP90 Heat-Shock Proteins
  • Hydroquinones
  • Ligands
  • NF-E2-Related Factor 2
  • NFE2L2 protein, human
  • Reactive Oxygen Species
  • Receptors, Aryl Hydrocarbon
  • Cytochrome P-450 CYP1A1
  • Benzene
  • Acetylcysteine