t-BHQ Provides Protection against Lead Neurotoxicity via Nrf2/HO-1 Pathway

Oxid Med Cell Longev. 2016:2016:2075915. doi: 10.1155/2016/2075915. Epub 2015 Dec 21.

Abstract

The neurotoxicity of lead has been well established, and oxidative stress is strongly associated with lead-induced neurotoxicity. Nrf2 is important for protection against oxidative stress in many disease models. We applied t-BHQ, which is an Nrf2 activator, to investigate the possible role of Nrf2 in the protection against lead neurotoxicity. t-BHQ significantly attenuated the oxidative stress in developmental rats by decreasing MDA level, as well as by increasing SOD activity and GSH content, in the hippocampus and frontal cortex. Furthermore, neuronal apoptosis was detected by Nissl staining, and Bax expression was inhibited in the t-BHQ-treated group. Results showed that t-BHQ suppressed ROS production and caspase 3/7 activity but increased intracellular GSH content, in SH-SY5Y cells under lead exposure. Moreover, in vivo and in vitro, t-BHQ enhanced the nuclear translocation of Nrf2 and binding to ARE areas but did not induce Nrf2 transcription. These phenomena were confirmed using RT-PCR, EMSA, Western blot, and immunofluorescence analyses. Subsequent upregulation of the expression of HO-1, NQO1, and GCLC was observed. However, knockdown of Nrf2 or HO-1 adversely affected the protective effects of t-BHQ against lead toxicity in SH-SY5Y cells. Thus, t-BHQ can protect against lead neurotoxicity, depending on the Nrf2/HO-1 pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Nucleus / drug effects
  • Cell Nucleus / metabolism
  • Heme Oxygenase-1 / metabolism*
  • Hippocampus / pathology
  • Humans
  • Hydroquinones / pharmacology*
  • Lead / toxicity*
  • Male
  • NF-E2-Related Factor 2 / genetics
  • NF-E2-Related Factor 2 / metabolism*
  • Neurons / drug effects
  • Neurons / metabolism
  • Neurons / pathology
  • Neuroprotection / drug effects*
  • Neurotoxins / toxicity*
  • Oxidation-Reduction / drug effects
  • Oxidative Stress / drug effects
  • Protein Transport / drug effects
  • Rats, Sprague-Dawley
  • Reactive Oxygen Species / metabolism
  • Signal Transduction / drug effects*
  • Up-Regulation / drug effects

Substances

  • Hydroquinones
  • NF-E2-Related Factor 2
  • Neurotoxins
  • Reactive Oxygen Species
  • Lead
  • 2-tert-butylhydroquinone
  • Heme Oxygenase-1