The Proteomic Profiling of Circulating Extracellular Vesicles of Western Diet and Chemical‐Induced Murine <scp>MASH</scp> Model

Metabolic dysfunction-associated steatotic liver disease (MASLD) is an increasingly prevalent chronic liver condition that can progress to severe complications such as metabolic dysfunction-associated steatohepatitis (MASH). Despite its growing burden, there are no reliable non-invasive biomarkers for tracking disease progression. In this study, we established a murine MASLD/MASH model using a high-fat diet and chemical (CCl₄) induction. We analyzed serum-derived extracellular vesicles (EVs) at 14 and 28 weeks to identify stage-specific proteomic signatures. Proteomic profiling of circulating EVs revealed key proteins associated with disease progression, including cathepsin B (Ctsb) and prosaposin (Psap) in early MASLD, and coagulation factor XIII A chain (F13a1) and polymeric immunoglobulin receptor (Pigr) in early MASH. The significant and severe MASH stages notably enriched Psma2, Psmb3, and Psmb5. These findings suggest EV-associated proteins may be promising non-invasive biomarkers for differentiating MASLD/MASH stages and guiding clinical monitoring.