Mitochondrial superoxide targets energy metabolism to modulate epigenetic regulation of NRF2-mediated transcription, 2021, Dhar et al

Highlights

• mPQ increases mitochondrial O2•- generation and suppresses mitochondrial functions.
• Mitochondrial O2•- blocks TCA cycle progression by inactivating IDH.
• Mitochondrial O2•- is an initiator of metabolic reprogramming that activates epigenetic regulation of gene transcription in response to mitochondrial dysfunction

Abstract

Mitochondria are central to the metabolic circuitry that generates superoxide radicals/anions (O2•-) as a by-product of oxygen metabolism. By regulating superoxide levels, manganese superoxide dismutase plays important roles in numerous biochemical and molecular events essential for the survival of aerobic life.

In this study, we used MitoParaquat (mPQ) to generate mitochondria-specific O2•- and stable isotope-resolved metabolomics tracing in primary human epidermal keratinocytes to investigate how O2•- generated in mitochondria regulates gene expression. The results reveal that isocitrate is blocked from conversion to α-ketoglutarate and that acetyl-coenzyme A (CoA) accumulates, which is consistent with a reduction in oxygen consumption rate and inactivation of isocitrate dehydrogenase (IDH) activity. Since acetyl-CoA is linked to histone acetylation and gene regulation, we determined the effect of mPQ on histone acetylation. The results demonstrate an increase in histone H3 acetylation at lysines 9 and 14. Suppression of IDH increased histone acetylation, providing a direct link between metabolism and epigenetic alterations. The activity of histone acetyltransferase p300 increased after mPQ treatment, which is consistent with histone acetylation. Importantly, mPQ selectively increased the nuclear levels and activity of the oxidative stress-sensitive nuclear factor erythroid 2-related factor 2.

Together, the results establish a new paradigm that recognizes O2•- as an initiator of metabolic reprogramming that activates epigenetic regulation of gene transcription in response to mitochondrial dysfunction.

Paywall, https://www.sciencedirect.com/science/article/abs/pii/S0891584921011692

 

This sort of basic biochemistry may be what is needed to finally make some progress into finding what goes wrong in ME.

 

Is there reason to think this is linked to ME/CFS?

 

There is a problem with energy production in ME. The basic biology of mitochondria and the details of energy production have not been discovered so the every step forward gives hope that the mechanisms of ME can be found.