Regulation of FOXOs and p53 by SIRT1 modulators under oxidative stress

PLoS One. 2013 Sep 11;8(9):e73875. doi: 10.1371/journal.pone.0073875. eCollection 2013.

Abstract

Excessive reactive oxygen species (ROS) induce apoptosis and are associated with various diseases and with aging. SIRT1 (sirtuin-1), an NAD+-dependent protein deacetylase, decreases ROS levels and participates in cell survival under oxidative stress conditions. SIRT1 modulates the transcription factors p53, a tumor suppressor and inducer of apoptosis, and the forkhead O (FOXO) family, both of which play roles for cell survival and cell death. In this study, we aimed to know which is working greatly among p53 and FOXOs transcription factors in SIRT1's cell protective functions under oxidative stress conditions. The antimycin A-induced increase in ROS levels and apoptosis was enhanced by SIRT1 inhibitors nicotinamide and splitomicin, whereas it was suppressed by a SIRT1 activator, resveratrol, and a SIRT1 cofactor, NAD+. SIRT1-siRNA abolished the effects of splitomicin and resveratrol. p53-knockdown experiment in C2C12 cells and experiment using p53-deficient HCT116 cells showed that splitomicin and resveratrol modulated apoptosis by p53-dependent and p53-independent pathways. In p53-independent cell protective pathway, we found that FOXO1, FOXO3a, and FOXO4 were involved in SOD2's upregulation by resveratrol. The knockdown of these three FOXOs by siRNAs completely abolished the SOD2 induction, ROS reduction, and anti-apoptotic function of resveratrol. Our results indicate that FOXO1, FOXO3a and FOXO4, are indispensable for SIRT1-dependent cell survival against oxidative stress, although deacetylation of p53 has also some role for cell protective function of SIRT1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AMP-Activated Protein Kinases / metabolism
  • Animals
  • Antimycin A / pharmacology
  • Apoptosis / drug effects
  • Apoptosis / genetics
  • Cell Cycle Proteins
  • Cell Line
  • Cell Proliferation
  • Enzyme Activation / drug effects
  • Forkhead Box Protein O1
  • Forkhead Box Protein O3
  • Forkhead Transcription Factors / genetics
  • Forkhead Transcription Factors / metabolism*
  • Gene Knockdown Techniques
  • Humans
  • Hydrogen Peroxide / metabolism
  • Hydrogen Peroxide / pharmacology
  • Mice
  • Oxidative Stress*
  • Reactive Oxygen Species / metabolism
  • Resveratrol
  • Sirtuin 1 / genetics
  • Sirtuin 1 / metabolism*
  • Stilbenes / pharmacology
  • Superoxide Dismutase / genetics
  • Superoxide Dismutase / metabolism
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism*

Substances

  • Cell Cycle Proteins
  • Forkhead Box Protein O1
  • Forkhead Box Protein O3
  • Forkhead Transcription Factors
  • FoxO3 protein, mouse
  • FoxO4 protein, mouse
  • Foxo1 protein, mouse
  • Reactive Oxygen Species
  • Stilbenes
  • Tumor Suppressor Protein p53
  • Antimycin A
  • Hydrogen Peroxide
  • Superoxide Dismutase
  • superoxide dismutase 2
  • AMP-Activated Protein Kinases
  • Sirtuin 1
  • Resveratrol

Grants and funding

This study was supported in part by the Ministry of Education, Culture, Sports, Science, and Technology of Japan (Grant-in-Aid 22590245) and by the Regional R&D Proposal-Based Program from the Northern Advancement Center for Science & Technology of Hokkaido, Japan. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.