Plaque stabilizing effects of apolipoprotein A-IV.

Area of Science:

• Cardiovascular Biology
• Atherosclerosis Research
• Lipid Metabolism

Background:

• High-density lipoprotein (HDL)-associated apolipoproteins play crucial roles in cardiovascular health.
• Apolipoprotein A-I (apoA-I) is known to inhibit plaque disruption.
• Apolipoprotein A-IV (apoA-IV) shares atheroprotective properties with apoA-I.

Purpose of the Study:

• To investigate the in vivo effects of apoA-IV on markers of atherosclerotic plaque stability.
• To determine if apoA-IV can mitigate plaque disruption and improve plaque composition.

Main Methods:

• ApoE-knockout mice on a high-fat diet were treated with apoA-IV or PBS.
• Plaque composition and stability markers were analyzed after 10 weeks.
• In vitro studies assessed apoA-IV's effects on macrophage-derived mediators.

Main Results:

• ApoA-IV treatment significantly reduced hemorrhagic plaque disruptions.
• Plaques in apoA-IV treated mice exhibited thicker fibrous caps, smaller lipid cores, and reduced inflammation.
• ApoA-IV decreased apoptosis, MMP-9 activity, and pro-inflammatory markers in plaques and macrophages.

Conclusions:

• ApoA-IV administration promotes a more stable atherosclerotic plaque phenotype.
• ApoA-IV treatment reduces the incidence of acute plaque disruptions in a mouse model.
• These findings highlight apoA-IV's potential as a therapeutic agent for atherosclerosis.