Knockdown of ANT2 reduces adipocyte hypoxia and improves insulin resistance in obesity

Decreased adipose tissue oxygen tension and increased expression of the transcription factor hypoxia-inducible factor-1 alpha (HIF-1 alpha) can trigger adipose tissue inflammation and dysfunction in obesity. Our current understanding of obesity-associated decreased adipose tissue oxygen tension is mainly focused on changes in oxygen supply and angiogenesis. Here, we demonstrate that increased adipocyte oxygen demand, mediated by activity of the mitochondrial protein adenine nucleotide translocase 2 (ANT2), is the dominant cause of adipocyte hypoxia. Deletion of adipocyte Ant2 (also known as Scl25a5) improves obesity-induced intracellular adipocyte hypoxia by decreasing obesity-induced adipocyte oxygen demand, without effects on mitochondrial number or mass, or oligomycin-sensitive respiration. This effect of adipocyte ANT2 knockout led to decreased adipose tissue HIF-1 alpha expression and inflammation with improved glucose tolerance and insulin resistance in both preventative and therapeutic settings. Our results suggest that ANT2 may be a target for the development of insulin-sensitizing drugs and that ANT2 inhibition might have clinical utility.