BNip3 regulates mitochondrial function and lipid metabolism in the liver

Mol Cell Biol. 2012 Jul;32(13):2570-84. doi: 10.1128/MCB.00167-12. Epub 2012 Apr 30.


BNip3 localizes to the outer mitochondrial membrane, where it functions in mitophagy and mitochondrial dynamics. While the BNip3 protein is constitutively expressed in adult liver from fed mice, we have shown that its expression is superinduced by fasting of mice, consistent with a role in responses to nutrient deprivation. Loss of BNip3 resulted in increased lipid synthesis in the liver that was associated with elevated ATP levels, reduced AMP-regulated kinase (AMPK) activity, and increased expression of lipogenic enzymes. Conversely, there was reduced β-oxidation of fatty acids in BNip3 null liver and also defective glucose output under fasting conditions. These metabolic defects in BNip3 null liver were linked to increased mitochondrial mass and increased hepatocellular respiration in the presence of glucose. However, despite elevated mitochondrial mass, an increased proportion of mitochondria exhibited loss of mitochondrial membrane potential, abnormal structure, and reduced oxygen consumption. Elevated reactive oxygen species, inflammation, and features of steatohepatitis were also observed in the livers of BNip3 null mice. These results identify a role for BNip3 in limiting mitochondrial mass and maintaining mitochondrial integrity in the liver that has consequences for lipid metabolism and disease.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • AMP-Activated Protein Kinases / metabolism
  • Adenosine Triphosphate / metabolism
  • Animals
  • Cells, Cultured
  • Fasting / metabolism
  • Fatty Acids / metabolism
  • Fatty Liver / etiology
  • Fatty Liver / metabolism
  • Gluconeogenesis
  • Glucose / metabolism
  • Lipid Metabolism*
  • Lipogenesis
  • Male
  • Membrane Proteins / deficiency
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mitochondria, Liver / metabolism*
  • Mitochondrial Proteins / deficiency
  • Mitochondrial Proteins / genetics
  • Mitochondrial Proteins / metabolism*
  • Models, Biological
  • Oxidation-Reduction
  • Oxygen Consumption


  • BNip3 protein, mouse
  • Fatty Acids
  • Membrane Proteins
  • Mitochondrial Proteins
  • Adenosine Triphosphate
  • AMP-Activated Protein Kinases
  • Glucose