{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Apolipoprotein E (APOE) has 3 main isoforms, known as APOE2, APOE3, and APOE4. APOE are produced by astrocytes in the brain and hepatocytes in the liver. It is a crucial protein in lipid transport, such as delivery of cholesterol to the neurons. APOE4 is the isoform known to contribute to the onset of Alzheimer’s disease. While it is expressed in many organs, in the brain APOE4 has been associated with deposition of insoluble amyloid plaques Aβ40 and Aβ42 in the interstitial fluid in the cortex and hippocampus. LDL receptor-related protein 1 (LRP1) metabolizes APOE4 and Aβ plaques, and the presence of APOE4 decreases the clearance or solubility of Aβ40 and Aβ42. APOE4 has been found to be a genetic factor in the pathology of Alzheimer’s disease, lewy body dementia, and Parkinson’s disease."}]}]}