Apoe Conditional Knockout mouse models

Apoe is the mouse ortholog of human APOE and encodes a 299 residue exchangeable apolipoprotein whose amino-terminal four-helix bundle presents the receptor binding surface for LDLR, LRP1 and heparan sulfate proteoglycans, while the carboxy-terminal domain mediates lipid binding and self-association, together directing clearance of chylomicron remnants and VLDL and controlling brain lipid and amyloid beta handling. Mouse Apoe resembles human APOE4 at the domain interaction level and lacks the human isoform series, so targeted replacement knockins carrying human APOE2, APOE3 or APOE4 coding sequence under the endogenous promoter are the only honest platform for isoform-dependent questions in Alzheimer disease, and they are routinely crossed to amyloid or tau models. Conventional null mice develop marked hypercholesterolemia and spontaneous atherosclerosis on chow, which remains the workhorse cardiovascular readout. Because Apoe and Apoj partially overlap in glial lipid transport, interpret CNS phenotypes with that in mind, and select humanized alleles when testing isoform-selective or ASO based therapeutics.

Tissue restricted knockout of Apoe keeps wild type function everywhere else. Breeding is often more robust, and the setup mirrors patient biology where mutations arise in a subset of cells.