Methodological Approach for the Evaluation of FOXO as a Positive Regulator of Antioxidant Genes
All four FOXO isoforms have been shown to respond to changes in the cellular redox status of the cell, and regulate the expression of target genes that in turn can modulate the cellular oxidative status. However, the mechanisms involved are still controversial. It is clear though that redox regulation of FOXO factors occurs at different levels. The proteins themselves are redox-sensitive and their capacity to bind their target sites seems to be at least partially dependent on their oxidative status. Importantly, several of the cofactors that are known to regulate FOXO transcriptional activity are also sensitive to changes in the cellular redox status, in particular the deacetylase SirT1 is activated in response to reduced levels of reducing equivalents (increased NAD+/NADH+ ratio) and the coactivator PGC-1α is induced in response to increased cellular oxidative stress. Furthermore, nuclear localization of FOXO factors is also regulated by proteins that, like AKT, are themselves regulated directly or indirectly by the cellular levels of reactive oxygen and nitrogen species. In this technical review, we aim to update the current status of our knowledge of how to handle redox-regulated FOXO factor research in order to better understand FOXO biology.
Key wordsFOXO Vectors Activity Cell culture Pro-survival Metabolism Stress response
This work was supported by grants from the Spanish “Ministerio de Economía Industria y Competitividad” (MINEICO) and FEDER funds [Grant numbers SAF2015-63904-R, SAF2015-71521-REDC] and from the EU H2020 framework programm Grant MSCA-ITN-2016-721236.
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