Hypermetabolic State Drives Platelet Dysfunction in Human and Mouse Metabolic Dysfunction-Associated Steatotic Liver Disease

BACKGROUND: Metabolic dysfunction-associated steatotic liver disease (MASLD) is a growing health concern given rising global prevalence, limited diagnostic and therapeutic tools, and strong association with cardiovascular disease. Platelets and oxidized phospholipids have been implicated in MASLD pathogenesis; however, the drivers and activities of platelets in MASLD remain overlooked. METHODS: We conducted a cross-sectional study to determine platelet metabolic and functional states in MASLD and to investigate whether oxidized phospholipids, which accumulate during MASLD, contribute to platelet dysfunction. The study included age-matched individuals with simple steatosis (n=42), steatohepatitis (n=28), metabolic dysfunction-associated cirrhosis (n=16), and controls without steatosis (n=23). Platelet function and metabolism were characterized by flow cytometry and Seahorse analysis. In vivo markers of platelet activation and plasma oxidized low-density lipoprotein were quantified by ELISA. The causal relationship between oxidized phospholipids and the platelet phenotype was investigated by comparing Ldlr −/− mice fed an Amylin Liver NASH diet to Amylin Liver NASH-fed E06-scFv/Ldlr −/− , transgenic mice that express a natural antibody (E06) that neutralizes oxidized phospholipids. RESULTS: We report that since early MASLD, in vivo markers of platelet secretion were elevated in plasma and platelets displayed heightened metabolic activity. In advanced MASLD, associated with MASH and cirrhosis, platelets were refractory to G-protein-coupled receptor stimulation, but more responsive to GPVI stimulation, promoting a secretory and procoagulant phenotype. Platelet dysfunction correlated with increased platelet mitochondrial activity and with blood levels of oxidized low-density lipoprotein, a major source of oxidized lipids. Ex vivo, the oxidized phospholipid oxPAPC recapitulated the increased mitochondrial activity and functional reprogramming observed in MASH platelets. In a mouse model of MASLD, neutralization of oxidized phospholipids partially mitigated diet-induced platelet dysfunction and binding to liver macrophages. CONCLUSIONS: In MASLD, we observed heightened platelet metabolic activity and changes in platelet reactivity, providing the basis to target platelet dysfunction for preventing hepatic and extra-hepatic complications of MASLD. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT05128253.