Left ventricular dysfunction in murine models of heart failure and in failing human heart is associated with a...

Area of Science:

• Cardiovascular Biology
• Molecular Cardiology
• Cell Membrane Dynamics

Background:

• Caveolins are essential scaffolding proteins within cell membrane invaginations called caveolae.
• Caveolin-3 is specifically expressed in muscle tissue, including the heart.
• The precise role of caveolin-3 in heart muscle disease remains under investigation.

Purpose of the Study:

• To investigate the impact of left ventricular dysfunction on caveolin protein expression.
• To explore the potential of caveolin-3 as a therapeutic target in heart failure.

Main Methods:

• Utilized two established murine models of heart failure (A(1)-adenosine receptor overexpression and tumor necrosis factor α overexpression).
• Analyzed caveolin-1, -2, and -3 mRNA and protein levels in cardiac tissue.
• Examined T-tubule morphology in isolated myocytes using confocal imaging.
• Correlated caveolin-3 expression with cardiac function parameters (fractional shortening) and human heart failure markers (Ca(2+)-ATPase).

Main Results:

• Left ventricular dysfunction in transgenic mice led to a significant decrease in caveolin-3 mRNA and protein, while caveolin-1 and -2 remained unchanged.
• Myocytes from affected mice showed disrupted T-tubule structure.
• Reduced caveolin-3 levels were also observed in hearts with tumor necrosis factor α-induced failure.
• A direct positive correlation was found between caveolin-3 expression and fractional shortening in mice.
• In human failing hearts, a positive correlation existed between caveolin-3 and Ca(2+)-ATPase, a heart failure marker.

Conclusions:

• Left ventricular dysfunction is associated with decreased caveolin-3 levels.
• Caveolin-3 expression is selectively affected in heart failure.
• Caveolin-3 represents a potential novel therapeutic target for heart failure treatment.