Pharmacological Inhibition of PTEN Restores Remote Ischemic Postconditioning Cardioprotection in Hypercholesterolemic Mice: Potential Role of PTEN/AKT/GSK3β SIGNALS

Shock. 2019 Nov;52(5):522-531. doi: 10.1097/SHK.0000000000001296.

Abstract

Although remote ischemic postconditioning (RIPC) was shown to confer cardioprotection against myocardial ischemia/reperfusion (I/R) injury in normal animals, whether RIPC-induced cardioprotection is altered in the presence of hypercholesterolemia, a comorbidity with acute myocardial infarction (AMI) patients has yet to be determined. Normal or 2% cholesterol chow was fed to male C57BL/6J mice for 12 weeks to induce hypercholesterolemia, then normal or hypercholesterolemic murine hearts were exposed to AMI by coronary artery ligation. RIPC was induced by four episodes of 5 min femoral artery occlusion followed by 5 min reperfusion immediately after myocardial reperfusion in mice. Following I/R, RIPC significantly attenuated postischemic infarct size, hindered cardiomyocyte apoptosis, improved cardiac systolic function, decreased phosphatase and tensin homolog deleted on chromosome ten (PTEN) expression, and further increased Akt and GSK-3β phosphorylation in non-hypercholesterolemic, but not in hypercholesterolemic mice. Application of the PTEN inhibitor bisperoxovanadium (BpV) (1.0 mg/kg) reduced postischemic infarct size, attenuated cardiomyocyte apoptosis, and improved cardiac dysfunction in normal, but not in hypercholesterolemic mice. Further, increased dose of BpV (2 mg/kg or 10 mg/kg) failed to rescue the detrimental effects of hypercholesterolemia on I/R in mice following I/R. Especially important, we demonstrated that the combination BpV and RIPC exerted marked cardioprotective effects both in normal and hypercholesterolemic mice with I/R, indicating that PTEN inhibition restores RIPC-elicited myocardial protection in the presence of hypercholesterolemia. Our results demonstrated that hypercholesterolemia attenuated RIPC-induced cardioprotection against I/R injury by alteration of PTEN/Akt/GSK3β signals, and inhibition of PTEN rescued RIPC-induced cardioprotection in the presence of hypercholesterolemia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Glycogen Synthase Kinase 3 beta / metabolism*
  • Hypercholesterolemia* / drug therapy
  • Hypercholesterolemia* / metabolism
  • Hypercholesterolemia* / pathology
  • Ischemic Postconditioning*
  • Male
  • Mice
  • PTEN Phosphohydrolase* / antagonists & inhibitors
  • PTEN Phosphohydrolase* / metabolism
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Signal Transduction*
  • Vanadium Compounds / pharmacology*

Substances

  • Vanadium Compounds
  • bisperoxovanadium
  • Glycogen Synthase Kinase 3 beta
  • Gsk3b protein, mouse
  • Proto-Oncogene Proteins c-akt
  • PTEN Phosphohydrolase
  • Pten protein, mouse