Alteration in mitochondrial Ca2+ uptake disrupts insulin signaling in hypertrophic cardiomyocytes

Tomás Gutiérrez, Valentina Parra, Rodrigo Troncoso, Christian Pennanen, Ariel Contreras-Ferrat, César Vasquez-Trincado, Pablo E. Morales, Camila Lopez-Crisosto, Cristian Sotomayor-Flores, Mario Chiong, Beverly A. Rothermel, Sergio Lavandero

Research output: Contribution to journalArticlepeer-review

35 Scopus citations

Abstract

Background: Cardiac hypertrophy is characterized by alterations in both cardiac bioenergetics and insulin sensitivity. Insulin promotes glucose uptake by cardiomyocytes and its use as a substrate for glycolysis and mitochondrial oxidation in order to maintain the high cardiac energy demands. Insulin stimulates Ca2+ release from the endoplasmic reticulum, however, how this translates to changes in mitochondrial metabolism in either healthy or hypertrophic cardiomyocytes is not fully understood. Results: In the present study we investigated insulin-dependent mitochondrial Ca2+ signaling in normal and norepinephrine or insulin like growth factor-1-induced hypertrophic cardiomyocytes. Using mitochondrion-selective Ca2+-fluorescent probes we showed that insulin increases mitochondrial Ca2+ levels. This signal was inhibited by the pharmacological blockade of either the inositol 1,4,5-triphosphate receptor or the mitochondrial Ca2+ uniporter, as well as by siRNA-dependent mitochondrial Ca2+ uniporter knockdown. Norepinephrine-stimulated cardiomyocytes showed a significant decrease in endoplasmic reticulum-mitochondrial contacts compared to either control or insulin like growth factor-1-stimulated cells. This resulted in a reduction in mitochondrial Ca2+ uptake, Akt activation, glucose uptake and oxygen consumption in response to insulin. Blocking mitochondrial Ca2+ uptake was sufficient to mimic the effect of norepinephrine-induced cardiomyocyte hypertrophy on insulin signaling. Conclusions: Mitochondrial Ca2+ uptake is a key event in insulin signaling and metabolism in cardiomyocytes.

Original languageEnglish (US)
Article number68
JournalCell Communication and Signaling
Volume12
Issue number1
DOIs
StatePublished - Nov 7 2014

Keywords

  • Akt
  • Calcium
  • Cardiac hypertrophy
  • Catecholamines
  • IGF-1
  • Inositol 1,4,5-triphosphate receptor
  • Insulin
  • Mitochondria

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Alteration in mitochondrial Ca<sup>2+</sup> uptake disrupts insulin signaling in hypertrophic cardiomyocytes'. Together they form a unique fingerprint.

Cite this