ApoAV

ApoAV, or apolipoprotein A-V, is a vertebrate protein encoded by the APOA5 gene in humans. It is expressed primarily in the liver and secreted into the bloodstream, where it associates with triglyceride-rich lipoproteins such as very low-density lipoprotein (VLDL) and chylomicrons. Despite its relatively small size, ApoA-V has a large influence on plasma triglyceride levels.

Functional studies indicate that ApoA-V influences triglyceride metabolism by modulating the processing and clearance of triglyceride-rich lipoproteins. It is thought to act by enhancing triglyceride hydrolysis via lipoprotein lipase and by affecting hepatic production or catabolism of VLDL, although the exact mechanisms remain under investigation. ApoA-V is present at low concentrations in plasma, and small changes in its amount or function can lead to significant changes in triglyceride levels.

Genetic variation in APOA5 is a major determinant of fasting plasma triglyceride concentration in humans. Numerous rare and common variants have been described; some reduce ApoA-V activity or secretion and are associated with hypertriglyceridemia, while others may have neutral or context-dependent effects. Because markedly elevated triglycerides can increase the risk of pancreatitis and cardiovascular disease, APOA5 is clinically relevant in the evaluation of lipid disorders.

Evolutionarily, APOA5 has homologs in other mammals, reflecting the conserved role of triglyceride metabolism pathways. Ongoing research aims to clarify ApoA-V’s precise biological functions and its potential as a therapeutic target for conditions involving hypertriglyceridemia.