SPA Promotes Atherosclerosis Through Mediating Macrophage Foam Cell Formation-Brief Report

Area of Science:

• Cardiovascular Research
• Immunology
• Molecular Biology

Background:

• Atherosclerosis is an inflammatory disease where macrophage foam cells are key.
• Surfactant protein A (SPA) regulates macrophage function in inflammation.
• The role of SPA in atherosclerosis and foam cell formation is unknown.

Purpose of the Study:

• To investigate the role of SPA in atherosclerosis.
• To determine SPA's effect on macrophage foam cell formation.

Main Methods:

• Assessed SPA expression in human and mouse atherosclerotic arteries.
• Utilized wild-type and SPA-deficient mice fed high-fat diets.
• Conducted in vitro studies with macrophages to assess foam cell formation.

Main Results:

• SPA expression is elevated in atherosclerotic lesions.
• SPA deficiency reduced hypercholesterolemia, atherosclerosis, and foam cell number.
• SPA deficiency decreased intracellular cholesterol and foam cell formation, downregulating CD36.
• SPA increased CD36 expression in human macrophages.

Conclusions:

• SPA is a novel factor promoting atherosclerosis.
• SPA enhances foam cell formation and atherosclerosis by increasing scavenger receptor CD36 expression.
• This leads to increased cellular oxidized low-density lipoprotein (OxLDL) uptake.