Redox regulation of antioxidants, autophagy, and the response to stress: Implications for electrophile therapeutics

• Published in: Free radical biology & medicine Vol. 71; pp. 196 - 207
• Main Authors: Levonen, Anna-Liisa, Hill, Bradford G., Kansanen, Emilia, Zhang, Jianhua, Darley-Usmar, Victor M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2014
• Subjects: Aldehydes - metabolism; Animals; Antioxidants - metabolism; Antioxidants - therapeutic use; Autophagy - genetics; Bioenergetics; Electrophiles; Gene Expression Regulation; Heat-Shock Proteins - genetics; Heat-Shock Proteins - metabolism; Humans; Hydrogen Peroxide - metabolism; Intracellular Signaling Peptides and Proteins - genetics; Intracellular Signaling Peptides and Proteins - metabolism; Keap1; Kelch-Like ECH-Associated Protein 1; NF-E2-Related Factor 2 - genetics; NF-E2-Related Factor 2 - metabolism; Nitric Oxide - metabolism; Nrf2; Oxidative Stress - drug effects; Oxidative Stress - genetics; Reactive Oxygen Species - metabolism; Signal Transduction; Unfolded Protein Response - genetics; ANT; p62/SQSTM1; PERK; LKB1; ALDH2; Bioenergetics; NNT; Nrf2; UPR; HSF1; IRE1; EMA; ME; mTOR; HSE; LC3; HSP; ESR; HSR; MS; G6PDH; GST; ER; AR; GRP78/BiP; NOS; ATG; Nox; ROS; Keap1; AMPK; ATM; Electrophiles; ATF6; GAPDH; HNE; COPD
• ISSN: 0891-5849; 1873-4596
• DOI: 10.1016/j.freeradbiomed.2014.03.025

Redox networks in the cell integrate signaling pathways that control metabolism, energetics, cell survival, and death. The physiological second messengers that modulate these pathways include nitric oxide, hydrogen peroxide, and electrophiles. Electrophiles are produced in the cell via both enzymatic and nonenzymatic lipid peroxidation and are also relatively abundant constituents of the diet. These compounds bind covalently to families of cysteine-containing, redox-sensing proteins that constitute the electrophile-responsive proteome, the subproteomes of which are found in localized intracellular domains. These include those proteins controlling responses to oxidative stress in the cytosol—notably the Keap1-Nrf2 pathway, the autophagy-lysosomal pathway, and proteins in other compartments including mitochondria and endoplasmic reticulum. The signaling pathways through which electrophiles function have unique characteristics that could be exploited for novel therapeutic interventions; however, development of such therapeutic strategies has been challenging due to a lack of basic understanding of the mechanisms controlling this form of redox signaling. In this review, we discuss current knowledge of the basic mechanisms of thiol-electrophile signaling and its potential impact on the translation of this important field of redox biology to the clinic. Emerging understanding of thiol-electrophile interactions and redox signaling suggests replacement of the oxidative stress hypothesis with a new redox biology paradigm, which provides an exciting and influential framework for guiding translational research. [Display omitted] •The oxidative stress paradigm cannot explain the mechanisms of action of reactive species in redox signaling.•The redox biology paradigm offers a new explanation for the lack of efficacy of lipid radical scavenging antioxidants such as α-tocopherol.•The redox biology paradigm proposes that loss of control of specific redox signaling leads to pathology.•This model allows for the development of specific molecular therapeutics for diseases of redox signaling dysfunction.