Sulforaphane reactivates cellular antioxidant defense by inducing Nrf2/ARE/Prdx6 activity during aging and oxidative stress

Sci Rep. 2017 Oct 26;7(1):14130. doi: 10.1038/s41598-017-14520-8.

Abstract

Upon oxidative stress and aging, Nrf2 (NFE2-related factor2) triggers antioxidant defense genes to defends against homeostatic failure. Using human(h) or rat(r) lens epithelial cells (LECs) and aging human lenses, we showed that a progressive increase in oxidative load during aging was linked to a decline in Prdx6 expression. DNA binding experiments using gel-shift and ChIP assays demonstrated a progressive reduction in Nrf2/ARE binding (-357/-349) of Prdx6 promoter. The promoter (-918) with ARE showed a marked reduction in young vs aged hLECs, which was directly correlated to decreased Nrf2/ARE binding. A Nrf2 activator, Sulforaphane (SFN), augmented Prdx6, catalase and GSTπ expression in dose-dependent fashion, and halted Nrf2 dysregulation of these antioxidants. SFN reinforced Nrf2/DNA binding and increased promoter activities by enhancing expression and facilitating Nrf2 translocalization in nucleus. Conversely, promoter mutated at ARE site did not respond to SFN, validating the SFN-mediated restoration of Nrf2/ARE signaling. Furthermore, SFN rescued cells from UVB-induced toxicity in dose-dependent fashion, which was consistent with SFN's dose-dependent activation of Nrf2/ARE interaction. Importantly, knockdown of Prdx6 revealed that Prdx6 expression was prerequisite for SFN-mediated cytoprotection. Collectively, our results suggest that loss of Prdx6 caused by dysregulation of ARE/Nrf2 can be attenuated through a SFN, to combat diseases associated with aging.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Active Transport, Cell Nucleus / drug effects
  • Adolescent
  • Adult
  • Aged
  • Aging / drug effects*
  • Animals
  • Antioxidants / metabolism*
  • Cell Nucleus / drug effects
  • Cell Nucleus / metabolism
  • Dose-Response Relationship, Drug
  • Gene Expression Regulation / drug effects
  • Humans
  • Isothiocyanates / chemistry*
  • Isothiocyanates / pharmacology*
  • Middle Aged
  • NF-E2-Related Factor 2 / genetics
  • NF-E2-Related Factor 2 / metabolism*
  • Oxidative Stress / drug effects*
  • Peroxiredoxin VI / genetics
  • Peroxiredoxin VI / metabolism*
  • Promoter Regions, Genetic / genetics
  • Rats
  • Rats, Sprague-Dawley
  • Response Elements / drug effects
  • Sulfoxides
  • Time Factors
  • Transcription, Genetic / drug effects
  • Up-Regulation / drug effects
  • Young Adult

Substances

  • Antioxidants
  • Isothiocyanates
  • NF-E2-Related Factor 2
  • Sulfoxides
  • Peroxiredoxin VI
  • Prdx6 protein, rat
  • sulforaphane