Inhibition of cardiac myocyte apoptosis improves cardiac function and abolishes mortality in the peripartum...

Area of Science:

• Cardiology
• Molecular Biology
• Pathophysiology

Background:

• Cardiac myocyte apoptosis is observed in heart failure, but its pathogenic role remains unclear.
• Transgenic mice overexpressing Galpha(q) develop lethal peripartum cardiomyopathy with significant apoptosis.
• This study investigates if inhibiting apoptosis can ameliorate cardiac dysfunction and improve survival in this model.

Purpose of the Study:

• To determine the causal role of cardiac myocyte apoptosis in Galpha(q)-induced peripartum cardiomyopathy.
• To evaluate the efficacy of caspase inhibition in improving cardiac function and survival.

Main Methods:

• Administration of a potent polycaspase inhibitor (IDN-1965) or vehicle via osmotic minipump to Galpha(q) mice during pregnancy.
• Assessment of cardiac caspase-3-like activity and myocyte apoptosis frequency.
• Evaluation of left ventricular function (dimensions, fractional shortening, dP/dt) and survival rates.

Main Results:

• IDN-1965 significantly suppressed cardiac caspase activity and reduced myocyte apoptosis.
• Caspase inhibition led to marked improvements in left ventricular dimensions and function (fractional shortening, dP/dt).
• Treatment with IDN-1965 completely prevented mortality in the Galpha(q) mice.

Conclusions:

• Reducing cardiac myocyte apoptosis through caspase inhibition improves cardiac function and survival in a model of peripartum cardiomyopathy.
• These results establish a causal link between cardiac myocyte apoptosis and cardiomyopathy pathogenesis in this model.
• Caspase inhibition emerges as a potential novel therapeutic target for heart failure treatment.