Purinergic and extracellular vesicle signaling in alcohol-induced blood-brain barrier breakdown and neuroimmune activation.

Chronic alcohol consumption is a major risk factor for neuroinflammation and cognitive decline, yet the molecular underpinnings connecting peripheral alcohol-induced injury to central nervous system (CNS) dysfunction remain poorly defined. Emerging evidence implicates purinergic P2X7 receptor (P2X7R) signaling and extracellular vesicles (EVs) as key mediators in peripheral-central communication. Ethanol exposure promotes oxidative stress, mitochondrial dysfunction, and blood-brain barrier (BBB) disruption, leading to sustained microglial activation and neuronal injury. Concurrently, alcohol-induced damage in the gut, liver, and lung, triggers systemic inflammation and EV release. These EVs, enriched in proinflammatory cytokines, miRNAs, mitochondrial DNA, and other DAMPs, can cross the compromised BBB and engage innate immune receptors, such as TLR4 and P2X7R, on glial cells, amplifying neuroimmune responses. In this review, we integrated recent findings on EV biogenesis, P2X7R signaling, and neurovascular dysfunction in the context of alcohol use disorder. We proposed a mechanistic model in which ethanol-triggered P2X7R activation drives EV release, turning these vesicles into inflammatory couriers that carry peripheral injury signals to the brain. We emphasize EV cargo as promising biomarkers of alcohol-related neurodegeneration and explore emerging therapies that target EV pathways or P2X7R to curb alcohol-induced CNS damage.