Hydrogen peroxide as a central redox signaling molecule in physiological oxidative stress: Oxidative eustress

• Published in: Redox biology 2017-04, Vol.11, p.613-619
• Main Author: Sies, Helmut
• Format: Article
• Language: English
• Subjects: Antioxidants - metabolism; H2O2; Humans; Hydrogen Peroxide - metabolism; Mitochondria; NADPH oxidases; Oxidation-Reduction; Oxidative Stress; Peroxiporins; Reactive Oxygen Species - metabolism; Redox regulation; Review; Signal Transduction
• ISSN: 2213-2317; 2213-2317
• DOI: 10.1016/j.redox.2016.12.035

Hydrogen peroxide emerged as major redox metabolite operative in redox sensing, signaling and redox regulation. Generation, transport and capture of H2O2 in biological settings as well as their biological consequences can now be addressed. The present overview focuses on recent progress on metabolic sources and sinks of H2O2 and on the role of H2O2 in redox signaling under physiological conditions (1–10nM), denoted as oxidative eustress. Higher concentrations lead to adaptive stress responses via master switches such as Nrf2/Keap1 or NF-κB. Supraphysiological concentrations of H2O2 (>100nM) lead to damage of biomolecules, denoted as oxidative distress. Three questions are addressed: How can H2O2 be assayed in the biological setting? What are the metabolic sources and sinks of H2O2? What is the role of H2O2 in redox signaling and oxidative stress? [Display omitted] •H2O2 is operative in redox sensing and redox signaling.•H2O2 reacts with metal centers and with sulfur/selenium compounds.•H2O2 links redox biology to phosphorylation/dephosphorylation.•Physiological (low-level, nM) steady-state of H2O2 is maintained in oxidative eustress.•Supraphysiological (pathological) level of H2O2 leads to oxidative distress.