APOE4 is widely recognized as a genetic risk factor for Alzheimer's disease (AD), implicated in 60-80% of all AD cases. Recent research suggests that microglia carrying the APOE4 genotype display abnormal lipid metabolism and accumulate lipid droplets, which may exacerbate the pathology of AD. Microglia play a critical role in immune surveillance within the central nervous system and are responsible for removing harmful particles and preserving neuronal function. The APOE4 genotype causes abnormal lipid metabolism in microglia, resulting in excessive accumulation of lipid droplets. This accumulation not only impairs the phagocytic and clearance capabilities of microglia but also disrupts their interactions with neurons, resulting in disorganization and neurodegenerative alterations at the neuronal network level. In addition, the presence of APOE4 modifies the metabolic landscape of microglia, particularly affecting purinergic signaling and lipid metabolism, thereby exacerbating the pathological processes of AD. In conclusion, the accumulation of lipid droplets and abnormal lipid metabolism may be critical mechanisms in the progression of AD in microglia carrying the APOE4 genotype.
Keywords: APOE4; Alzheimer's disease; apolipoprotein E; lipid metabolism; microglia.