Endothelin-1 overexpression restores diastolic function in eNOS knockout mice

Area of Science:

• Cardiovascular Physiology
• Molecular Cardiology
• Proteomics

Background:

• The cardiac nitric oxide (NO) and endothelin-1 (ET-1) systems are crucial for heart function.
• An imbalance between NO and ET-1 is implicated in cardiovascular diseases.
• Understanding the interplay between ET-1 and NO is vital for treating cardiac dysfunction.

Purpose of the Study:

• To investigate the cardiac effects of excessive ET-1 in the context of nitric oxide deficiency.
• To compare left ventricular function and morphology in various mouse models.

Main Methods:

• Utilized wild-type, ET-1 transgenic (ET(+/+)), endothelial nitric oxide synthase knockout (eNOS(-/-)), and ET(+/+)eNOS(-/-) mice.
• Assessed left ventricular function via catheterization.
• Analyzed cardiac proteome using 2D gel electrophoresis and mass spectrometry.

Main Results:

• eNOS(-/-) and ET(+/+)eNOS(-/-) mice exhibited hypertension.
• eNOS(-/-) mice developed diastolic dysfunction, which was rescued in ET(+/+)eNOS(-/-) mice.
• ET-1 overexpression in eNOS(-/-) mice altered antioxidant enzymes, sarcomere proteins, and energy metabolism (favoring glycolysis).

Conclusions:

• Cardiac ET-1 transgenic overexpression rescues diastolic dysfunction in eNOS-deficient mice.
• Cardiac ET-1 overexpression in eNOS deficiency regulates proteins involved in oxidative stress, myocyte contractility, and energy metabolism.