A pig model of human radiation-induced veno-occlusive liver disease reveals ferroptosis as a therapeutic target

Radiation-induced liver disease (RILD) is a significant complication of radiotherapy and radiation-based preconditioning for cell transplantation. Despite its importance, understanding its pathogenesis and developing effective therapies have been challenging due to the lack of an appropriate animal model that faithfully reproduces the pathological hallmarks of RILD. In this study, given their anatomical and physiological similarities to humans, we used Bama miniature pigs to establish a reliable large-animal model of RILD through a dose-escalation study using hypofractionated stereotactic body radiation therapy. Pigs receiving 40 Gy radiation developed RILD symptoms and exhibited significant liver dysfunction within 4 weeks, closely resembling human disease progression. Moreover, the pigs developed key pathological RILD hallmarks, including hepatic veno-occlusive disease, centrilobular necrosis, liver fibrosis, and compromised liver regeneration. Through single-nucleus RNA sequencing (snRNA-seq) and histological analyses, we found that hepatocytes in the RILD pig model underwent ferroptosis. Notably, treating these pigs with the ferroptosis inhibitor Liproxstatin-1 after irradiation significantly reversed the symptoms and pathological features of RILD and enhanced liver regeneration, particularly by promoting the proliferation of hepatocytes and endothelial cells. These results underscore the role of hepatocyte ferroptosis as a pivotal driver of RILD and highlight its potential as a therapeutic target. Our study provides a valuable large-animal platform for advancing the understanding and treatment of RILD, as well as optimizing radiation-based therapies and preconditioning strategies. Overall design: To comprehensively understand the pathogenesis and molecular mechanisms underlying RILD in the early stages, we performed snRNA-seq on liver biopsy samples from the 40 Gy group on day 14 and non-irradiated controls (0 Gy). To further investigate the therapeutic mechanism of Lip-1 in preventing RILD, we performed snRNA-seq analysis on liver biopsy samples from pigs in the control group (40 Gy) and Lip-1 treatment group (Lip-1) 14 days post-irradiation.