APOA4

Apolipoprotein A-IV (APOA4), also known as APOAIV, is a 46-kilodalton glycoprotein synthesized mainly by intestinal enterocytes. It is a key component of chylomicrons and high-density lipoproteins (HDL), driving triglyceride clearance via lipoprotein lipase activation and facilitating reverse cholesterol transport through interaction with scavenger receptor class B type I (SR-BI). Additionally, it regulates satiety via the gut-brain axis, curbing food intake by signaling to hypothalamic centers.
Reduced APOA4 levels are associated with obesity, type 2 diabetes, and increased cardiovascular disease risk due to impaired lipid homeostasis. Current research explores APOA4 mimetics or gene therapy to enhance its lipid-regulating functions, though no targeted drugs have yet been clinically approved. This protein remains a promising target for metabolic disorder interventions.