Omentin prevents myocardial ischemic injury through AMP-activated protein kinase- and Akt-dependent mechanisms

Area of Science:

• Cardiovascular Research
• Molecular Cardiology
• Adipokine Signaling

Background:

• Obesity is a significant risk factor for ischemic heart disease.
• Omentin, a circulating adipokine, is often reduced in obese individuals.
• Understanding omentin's role is crucial for managing obesity-related cardiovascular risks.

Purpose of the Study:

• To investigate the protective effects of omentin against myocardial ischemia/reperfusion (I/R) injury.
• To elucidate the molecular mechanisms underlying omentin's cardioprotective actions.
• To assess omentin's therapeutic potential in a mouse model of I/R injury.

Main Methods:

• Assessed cardiac function and perfusion defects in patients post-myocardial infarction.
• Induced myocardial ischemia/reperfusion (I/R) in a mouse model.
• Administered human omentin systemically and via fat-specific overexpression in mice.
• Utilized Western blotting to examine AMP-activated protein kinase (AMPK) and Akt phosphorylation.
• Investigated omentin's effects on cultured cardiomyocytes under hypoxia/reoxygenation.

Main Results:

• Elevated plasma omentin levels correlated with improved heart function and reduced damage in patients after reperfusion therapy.
• Systemic omentin administration in mice significantly reduced infarct size and apoptosis post-I/R.
• Omentin treatment enhanced AMPK and Akt phosphorylation in the ischemic heart.
• Fat-specific omentin overexpression also decreased infarct size.
• Inhibition of AMPK or Akt pathways abrogated omentin's protective effects against I/R injury and apoptosis.

Conclusions:

• Omentin acts as a cardioprotective adipokine, mitigating acute ischemic injury.
• Omentin suppresses myocyte apoptosis through both AMP-activated protein kinase (AMPK)- and Akt-dependent pathways.
• These findings highlight omentin as a potential therapeutic target for ischemic heart disease.