APOE-stratified Proteomic and Metabolomic Analysis Reveals Mitochondrial Dysfunction Inflammation and Lipid Dysregulation in Alzheimer's Disease.

Apolipoprotein E (APOE) ε4 is the strongest genetic risk factor for Alzheimer's disease (AD). However, it is known that other pathways independent of APOE also play a role in AD. Disentangling APOE-dependent and independent effects is instrumental for understanding the biology of AD. We conducted an APOE-stratified multi-omic analysis in multiple large datasets to identify AD-associated plasma proteins and metabolites. More than 64% of the identified proteins were not found in non-APOE stratified studies, and 17% of the proteins showed APOE-specific trends. Mitochondrial dysfunction was associated in AD independently of APOE and was accompanied by disruptions in glucose and lipid metabolism and cell death and increased in inflammatory signaling activation. Lipid upregulation was found in AD cases when compared with controls with the same APOE genotype, indicating that additional factors beyond APOE affect lipid regulation and AD risk. These findings may be informative in guiding the development of effective medications for AD.