More importantly, the drug resistance of MCF-7/ADR cells could be reversed via the inhibition of mitochondrial energy supply approach caused by the "explosion" of NBMTNs.
As for mitochondrial energy supply, pathway-based and gene-based analyses have independently indicated a reduction in glycolytic activity.
Thus interventions that alter mitochondrial substrate supply or Δp could affect both O2− production and matrix H2O2 degradation.
To exclude that the effects of ACH1 or MPC1 deletion were simply due to a general defect in mitochondrial AcCoA supply, we tested whether genetic overexpression of ACS2 mimicked the effects of blocking mitochondrial AcCoA pathways.
Mitochondrial energy supply is fundamental to cellular viability, and the interruption of key mitochondrial processes disrupts normal cellular bioenergetics, impairs cellular function, and subsequently leads to cell death by either necrosis or apoptosis [ 24].
Together, this strongly suggests that neither the specific CoA-transferase function of Ach1p nor mitochondrial pyruvate supply by Mpc1p was specifically responsible for the autophagic deficiency of ach1 or mpc1 mutant cells.
For example, it has been argued that the metabolic alterations induced by metformin in isolated skeletal muscle cells are not consistent with the interruption of mitochondrial energy supply; instead, they better reflect direct inhibition of the enzyme AMP deaminase [ 27].
An increasing number of evidences support the view that the coordination between mitochondrial ATP supply and mechanical activity demand is highly dependent on an efficient Ca2+ transfer from SR to mitochondria, and that altered SR mitochondria Ca2+ exchange may underlie the pathophysiology of several cardiac diseases.
On one hand, it stimulates mitochondrial proliferation to supply energy to meet the need for cell survival, including repair of damage and synthesis of new proteins.
With the exception of initial muscle contraction, increased anaerobic glycolytic ATP production is adaptive for a fall in mitochondrial (aerobic) ATP supply only when associated with a decrease in ATP consumption, imposing a new hierarchical setting on the different ATP consuming pathways.
Loss of NNT activity in a variety of biological models is associated with a lower supply of mitochondrial NADPH, increased mitochondrial ROS production and decreased [GSH]/[GSSG] ratio [34], making mitochondria more susceptible to ROS-induced damage [20], [34], [35].
