APOE

APOE (Apolipoprotein E): APOE, a protein primarily synthesized by the liver and astrocytes in the brain, is crucial for lipid metabolism and transport, particularly in the central nervous system (CNS). It plays a significant role in the clearance of lipoproteins from circulation and the redistribution of cholesterol and other lipids to cells via interactions with cell surface receptors. APOE exists in three common isoforms—APOE2, APOE3, and APOE4—each encoded by a different allele of the APOE gene. These isoforms differ in their affinity for lipoprotein receptors and their subsequent impact on lipid metabolism. APOE4, in particular, has been extensively studied due to its association with an increased risk of Alzheimer's disease (AD). It is involved in the regulation of amyloid-beta (Aβ) metabolism, influencing the aggregation and clearance of Aβ peptides in the brain. Beyond its role in lipid metabolism, APOE has been implicated in various physiological processes, including neuronal repair, synaptic plasticity, and neuroinflammation. Understanding the intricate functions of APOE and its isoforms is crucial for unraveling the mechanisms underlying neurodegenerative diseases and developing targeted therapeutic interventions.