Compensatory hypertrophy induced by ventricular cardiomyocyte-specific COX-2 expression in mice

Area of Science:

• Cardiovascular Biology
• Molecular Cardiology
• Inflammation Research

Background:

• Cyclooxygenase-2 (COX-2) plays a key role in inflammation during stress and disease.
• COX-2 inhibitors have been linked to increased risks of myocardial infarction and stroke.
• The specific impact of COX-2 in the intact heart requires further investigation.

Purpose of the Study:

• To investigate the direct impact of Cyclooxygenase-2 (COX-2) overexpression in ventricular myocytes on cardiac structure and function.
• To establish a transgenic mouse model for studying COX-2 effects in the heart.

Main Methods:

• Development of a transgenic mouse model using a loxP-Cre system for specific COX-2 overexpression in ventricular myocytes.
• Comprehensive analysis including histological, functional, and molecular assessments of the heart.

Main Results:

• Ventricular myocyte-specific COX-2 overexpression led to significant cardiac hypertrophy.
• Activation of fetal gene markers was observed, indicating molecular remodeling.
• Despite structural and molecular changes, cardiac function was preserved.

Conclusions:

• Specific induction of COX-2 and prostaglandin synthesis in vivo is sufficient to cause compensated cardiac hypertrophy.
• This model provides insights into the role of COX-2 in cardiac remodeling independent of systemic inflammation.