Nrf2 for cardiac protection: pharmacological options against oxidative stress.

Myocardial ischemia or reperfusion increases the generation of reactive oxygen species (ROS) from damaged mitochondria, NADPH oxidases, xanthine oxidase, and inflammation. ROS can be removed by eight endogenous antioxidant and redox systems, many components of which are expressed under the influence of the activated Nrf2 transcription factor. Transcriptomic profiling, sequencing of Nrf2-bound DNA, and Nrf2 gene knockout studies have revealed the power of Nrf2 beyond the antioxidant and detoxification response, from tissue recovery, repair, and remodeling, mitochondrial turnover, and metabolic reprogramming to the suppression of proinflammatory cytokines. Multifaceted regulatory mechanisms for Nrf2 protein levels or activity have been mapped to its functional domains, Nrf2-ECH homology (Neh)1–7. Oxidative stress activates Nrf2 via nuclear translocation, de novo protein translation, and increased protein stability due to removal of the Kelch-like ECH-associated protein 1 (Keap1) checkpoint, or the inactivation of β-transducin repeat-containing protein (β-TrCP), or Hmg-CoA reductase degradation protein 1 (Hrd1). The promise of small-molecule Nrf2 inducers from natural products or derivatives is discussed here. Experimental evidence is presented to support Nrf2 as a lead target for drug development to further improve the treatment outcome for myocardial infarction (MI). Myocardial ischemic reperfusion leads to increased oxidative stress and cell death by necrosis, apoptosis, and necroptosis. During oxidative stress, the activity of Nrf2 as a transcription factor is regulated by protein stability, translation, nuclear localization, and protein–protein interactions. The Nrf2 transcription factor controls the expression of key components in eight antioxidant and redox systems for the removal of reactive oxygen species. The genes under the influence of Nrf2 status suggest its involvement in mitochondrial turnover, tissue recovery, repair, or remodeling, metabolic reprogramming, and the limitation of proinflammatory cytokines. Small-molecule Nrf2 inducers have shown promise in eliciting cardiac protection and inhibiting inflammation in experimental animals, suggesting a future direction for the development of nontoxic Nrf2 inducers using modern technologies. [ABSTRACT FROM AUTHOR]