SIRT3 gene expression: a link between inherited mitochondrial DNA variants and oxidative stress.

Signaling pathways between mitochondrial and nuclear genomes are activated to preserve cellular homeostasis, especially in the event of stress. Using cybrid cell lines, we investigated whether inherited mitochondrial DNA (mtDNA) variants modulate the expression profiles of mammalian sirtuins (SIRT1-7) under oxidative stress conditions. We found that the expression of the SIRT3 gene was down-regulated in cybrids harbouring mtDNA of the J haplogroup, which correlated with mitochondrial function, resulting in a decline of NAD+/NADH and ATP levels. Overall, the data reported here highlight a link between SIRT3, mitochondrial DNA variability and mitochondrial functionality, three fundamental components of the cellular stress response.