A conserved role for phosphatidylinositol 3-kinase but not Akt signaling in mitochondrial adaptations that accompany physiological cardiac hypertrophy.

Academic Article


  • Physiological cardiac hypertrophy is associated with mitochondrial adaptations that are characterized by activation of PGC-1alpha and increased fatty acid oxidative (FAO) capacity. It is widely accepted that phosphatidylinositol 3-kinase (PI3K) signaling to Akt1 is required for physiological cardiac growth. However, the signaling pathways that coordinate physiological hypertrophy and metabolic remodeling are incompletely understood. We show here that activation of PI3K is sufficient to increase myocardial FAO capacity and that inhibition of PI3K signaling prevents mitochondrial adaptations in response to physiological hypertrophic stimuli despite increased expression of PGC-1alpha. We also show that activation of the downstream kinase Akt is not required for the mitochondrial adaptations that are secondary to PI3K activation. Thus, in physiological cardiac growth, PI3K is an integrator of cellular growth and metabolic remodeling. Although PI3K signaling to Akt1 is required for cellular growth, Akt-independent pathways mediate the accompanying mitochondrial adaptations.
  • Authors

    Published In

  • Cell Metabolism  Journal
  • Keywords

  • Adaptation, Physiological, Animals, Cardiomegaly, Fatty Acids, Gene Expression Regulation, Isoenzymes, Mice, Mice, Mutant Strains, Mitochondria, Myocytes, Cardiac, Oxidation-Reduction, Phosphatidylinositol 3-Kinases, Physical Conditioning, Animal, Protein Isoforms, Protein Kinase C, Proto-Oncogene Proteins c-akt, Signal Transduction
  • Digital Object Identifier (doi)

    Author List

  • O'Neill BT; Kim J; Wende AR; Theobald HA; Tuinei J; Buchanan J; Guo A; Zaha VG; Davis DK; Schell JC
  • Start Page

  • 294
  • End Page

  • 306
  • Volume

  • 6
  • Issue

  • 4