PI3Kγ Inhibition Protects Against Diabetic Cardiomyopathy in Mice

Rev Esp Cardiol (Engl Ed). 2017 Jan;70(1):16-24. doi: 10.1016/j.rec.2016.04.034. Epub 2016 Jul 13.
[Article in English, Spanish]

Abstract

Introduction and objectives: Cardiovascular diseases, including cardiomyopathy, are the major complications in diabetes. A deeper understanding of the molecular mechanisms leading to cardiomyopathy is critical for developing novel therapies. We proposed phosphoinositide3-kinase gamma (PI3Kγ) as a molecular target against diabetic cardiomyopathy, given the role of PI3Kγ in cardiac remodeling to pressure overload. Given the availability of a pharmacological inhibitor of this molecular target GE21, we tested the validity of our hypothesis by inducing diabetes in mice with genetic ablation of PI3Kγ or knock-in for a catalytically inactive PI3Kγ.

Methods: Mice were made diabetic by streptozotocin. Cardiac function was assessed by serial echocardiographic analyses, while fibrosis and inflammation were evaluated by histological analysis.

Results: Diabetes induced cardiac dysfunction in wild-type mice. Systolic dysfunction was completely prevented, and diastolic dysfunction was partially blocked, in both PI3Kγ knock-out and kinase-dead mice. Cardiac dysfunction was similarly rescued by administration of the PI3Kγ inhibitor GE21 in a dose-dependent manner. These actions of genetic and pharmacological PI3Kγ inhibition were associated with a decrease in inflammation and fibrosis in diabetic hearts.

Conclusions: Our study demonstrates a fundamental role of PI3Kγ in diabetic cardiomyopathy in mice and the beneficial effect of pharmacological PI3Kγ inhibition, highlighting its potential as a promising strategy for clinical treatment of cardiac complications of diabetic patients.

Keywords: Cardiomyopathy; Diabetes mellitus; Fármacos en investigación; Investigational drugs; Miocardiopatía; Mouse; PI3Kγ protein; Proteína PI3Kγ; Ratón.

MeSH terms

  • Animals
  • Class Ib Phosphatidylinositol 3-Kinase / metabolism
  • Diabetic Cardiomyopathies / diagnosis
  • Diabetic Cardiomyopathies / drug therapy*
  • Diabetic Cardiomyopathies / enzymology
  • Diabetic Cardiomyopathies / physiopathology
  • Disease Models, Animal
  • Echocardiography
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Myocardium / enzymology
  • Myocardium / pathology
  • Phosphoinositide-3 Kinase Inhibitors*

Substances

  • Phosphoinositide-3 Kinase Inhibitors
  • Class Ib Phosphatidylinositol 3-Kinase
  • Pik3cg protein, mouse