Portal vein thrombosis (PVT) is a challenging and controversial complication of cirrhosis. Experimental models that reproduce cirrhotic PVT and effective pharmacological therapies are limited. We aimed to investigate the nature course and mechanisms of PVT in cirrhosis. A novel PVT model was developed via two-step total portal vein ligation in healthy and thioacetamide (TAA)-cirrhotic rats. Circulating and liver-infiltrating neutrophils were isolated from individuals with cirrhosis to examine neutrophil extracellular traps (NETs) and explore their unique characteristics and implications in PVT-associated fibrosis in cirrhosis. We further validated macrophage–myofibroblast transition (MMT) via multiplex immunofluorescence and single-cell sequencing. In the experimental model, cirrhosis promoted PVT development and portal vein intimal thickening. Interestingly, cirrhosis promoted spontaneous resolution of PVT due to instability of thrombus structure, along with pulmonary and intrahepatic clots. NETs-MMT mediate cirrhotic PVT and PVT-associated fibrosis, including fibrotic thrombus remodeling and increased hepatic collagen deposition. Mechanistically, caspase-4-dependent activation of neutrophils and GSDMD mediated the formation of NETs. The extracellular DNA of NETs promoted TGF-β1/Smad3-driven MMT. Inhibiting GSDMD with disulfiram suppressed cirrhotic PVT and prevented associated fibrosis. The cirrhotic PVT model reflected the following three main characteristics of cirrhotic PVT: spontaneous resolution, immunothrombosis, and intimal fibrosis. Targeting NETs with GSDMD inhibitors may serve as a new therapeutic concept to treat cirrhotic PVT.

Background: Lipotoxicity, driven by dysregulated lipid metabolism, is a key initiator of hepatocyte injury in metabolic dysfunction–associated steatotic liver disease (MASLD). β-1,4-galactosyltransferase 1 (B4GALT1), which primarily mediates galactosylation of glycoproteins and glycolipids, is involved in the regulation of plasma lipid composition. Previous studies have implicated aberrant glycosylation in MASLD progression. However, the role and underlying molecular mechanisms of B4GALT1 in MASLD progression remain unclear. Methods and Results: The protein levels of B4GALT1 were elevated in patients with MASLD as well as in a murine model of MASLD induced by choline-deficient, L–amino acid–defined, high-fat diet (CDAHFD), with a more pronounced increase observed in MASH. Hepatocyte-specific B4galt1 -knockout mice exhibited significantly attenuated hepatic steatosis and inflammation, but not fibrosis. In addition, hepatic B4GALT1 deficiency suppressed the expression of lipogenic genes, reduced lipid accumulation, and inhibited ferroptosis mediated by lipid peroxidation. Mechanistically, B4GALT1 deficiency impaired the N-glycosylation of peroxisome proliferator-activated receptor gamma (PPARγ), leading to its stabilization. Increased PPARγ protein, in turn, transcriptionally repressed acyl-CoA synthetase long chain family member 4 (ACSL4), thereby mitigating lipid peroxidation. Conversely, PPARγ overexpression in steatotic hepatocytes rescued the pro-ferroptotic phenotype driven by B4GALT1. Conclusions: Our findings suggest that B4GALT1 plays a crucial role in MASLD progression by targeting lipid peroxidation in hepatocytes via the PPARγ/ACSL4 axis, thus highlighting a potential therapeutic target for MASLD.