Nicotinamide nucleotide transhydrogenase (NNT) deficiency dysregulates mitochondrial retrograde signaling and impedes proliferation

作者：Ho Hung Yao^*; Lin Yu Ting; Lin Gigin; Wu Pei Ru; Cheng Mei Ling

来源：Redox Biology, 2017, 12: 916-928.

DOI：10.1016/j.redox.2017.04.035

• Transhydrogenase
• Mitochondria
• Metabolomics
• HIF-1 alpha
• HDAC1

To study the physiological roles of NADH and NADPH homeostasis in cancer, we studied the effect of NNT knockdown on physiology of SK-Hep1 cells. NNT knockdown cells show limited abilities to maintain NAD(+) and NADPH levels and have reduced proliferation and tumorigenicity. There is an increased dependence of energy production on oxidative phosphorylation. Studies with stable isotope tracers have revealed that under the new steady-state metabolic condition, the fluxes of TCA and glycolysis decrease while that of reductive carboxylation increases. Increased [alpha-ketoglutarate]/[ succinate] ratio in NNT-deficient cells results in decrease in HIF-1 alpha level and expression of HIF-1 alpha regulated genes. Reduction in NADPH level leads to repression of HDAC1 activity and an increase in p53 acetylation. These findings suggest that NNT is essential to homeostasis of NADH and NADPH pools, anomalies of which affect HIF-1 alpha- and HDAC1-dependent pathways, and hence retrograde response of mitochondria.

• 出版日期2017-8
• 单位长春大学