The synthesis and secretion of apoE. Hepatic parenchymal cells are the principal apoE producing cells, presumably accounting for 60% to 75% of apoE in plasma, followed by astrocytes, which are the main apoE producing cells in the nervous system. ApoE mRNA can also be found in spleen, lung, kidney, peripheral nerves, muscular tissue, adrenal, ovary and testis, and so forth. In the nervous system, apoE mRNA is present in astrocytes, nonmyelinating Schwann cells, ependymal cells, microglia, and neurons, and so forth. BCs denotes blood cells; PNS denotes peripheral nervous system; CSF denotes cerebrospinal fluid.
