ADAMTS13 Improves Hepatic Platelet Accumulation in Pyrrolizidine Alkaloids-induced Liver Injury.

Background and aims: Pyrrolizidine alkaloids (PAs), widely distributed in plants, are known to induce liver failure. Hepatic platelet accumulation has been reported during the progression of PA-induced liver injury (PA-ILI). This study aimed to investigate the mechanisms underlying platelet accumulation in PA-ILI.

Methods: Cases of PA-ILI, non-PA-ILI, and control subjects were collected from patients hospitalized at Zhongshan Hospital, Fudan University (Shanghai, China) between 2012 and 2019. A mouse model of PA-ILI was established using monocrotaline administration. Liver RNA sequencing was performed, and gene interactions were analyzed using the Search Tool for the Retrieval of Interacting Genes/Proteins online database. Low-molecular-weight heparin and recombinant a disintegrin and metalloproteinase with a thrombospondin type I motif member 13 (ADAMTS13) were applied. The necrotic liver area, hepatic platelet accumulation, and von Willebrand factor (VWF) deposition were examined using hematoxylin and eosin staining and immunofluorescence assay.

Results: Hepatic platelet accumulation, necrotic area expansion, and increased VWF expression were observed in both PA-ILI patients and mice. The Search Tool for the Retrieval of Interacting Genes/Proteins database indicated that ADAMTS13 regulates VWF expression and was differentially expressed in the livers of PA-ILI mice. Plasma and hepatic ADAMTS13 levels were significantly downregulated in both PA-ILI patients and mice. Systemic administration of recombinant ADAMTS13 decreased hepatic platelet accumulation, downregulated VWF expression, and mitigated mouse hepatic necrosis.

Conclusions: Hepatic platelet accumulation in PA-ILI was confirmed in both patients and mice. Deficiency of ADAMTS13 plays a critical role in platelet accumulation in PA-ILI, suggesting that ADAMTS13 could be a potential therapeutic target for this condition.