Lipid network of plasma extracellular vesicles reveals sex-based differences in the lipidomic profile from patients with alcohol use disorder

Alcohol use disorder (AUD) is one of the most common psychiatric disorders, and the consumption of this substance is considered one of the main causes of preventable deaths worldwide. Lipids play a crucial functional role in cell membranes, however little is known about the role of lipids containing extracellular vesicles (EVs), as regulatory molecules and biomarkers. In this study, a highly sensitive lipidomic strategy is employed to characterize plasma EV lipid species from individuals with AUD, to evaluate differential functional roles and enzymatic activity networks to improve the knowledge of lipid metabolism in the alcohol consumption. Plasma EV lipids from female and male patients with AUD and healthy individuals were analyzed to obtain lipid differential abundance, as well as biological interpretation of LINEX 2 lipidomics data, evaluating enzymatic dysregulation through an enrichment algorithm. Our results showed for the first time that females with AUD exhibit greater substrate-product changes in LPC and PC lipids, as well as phospholipases and acyltransferases activity, potentially linked to cancer progression and neuroinflammation. Conversely, males with AUD showed dysregulation in Cer and SM lipid, involving sphingomyelinases, sphingomyelin phosphodiesterase, and sphingomyelin synthase, which could be related with hepatotoxicity. Notably, females with AUD showed LION-terms associated with “positive intrinsic curvature”, while males exhibited “negative intrinsic curvature, contributing to vesicle fusion processes. These methodological developments allow a better understanding of lipid metabolism and its regulatory mechanisms, which contributes not only to identify novel lipid targets, but also the discovery of sex-specific clinical biomarkers in the AUD.