Apolipoprotein E
Cholesterol-transporting protein most notably implicated in Alzheimer's disease / From Wikipedia, the free encyclopedia
Apolipoprotein E (Apo-E) is a protein involved in the metabolism of fats in the body of mammals. A subtype is implicated in Alzheimer's disease and cardiovascular diseases.[5] It is encoded in humans by the gene APOE.
Apo-E belongs to a family of fat-binding proteins called apolipoproteins. In the circulation, it is present as part of several classes of lipoprotein particles, including chylomicron remnants, VLDL, IDL, and some HDL.[6] Apo-E interacts significantly with the low-density lipoprotein receptor (LDLR), which is essential for the normal processing (catabolism) of triglyceride-rich lipoproteins.[7] In peripheral tissues, Apo-E is primarily produced by the liver and macrophages, and mediates cholesterol metabolism. In the central nervous system, Apo-E is mainly produced by astrocytes and transports cholesterol to neurons[8] via Apo-E receptors, which are members of the low density lipoprotein receptor gene family.[9] Apo-E is the principal cholesterol carrier in the brain.[10] APOE qualifies as a checkpoint inhibitor of the classical complement pathway by complex formation with activated C1q.[11]