Novel defatting strategies reduce lipid accumulation in primary human culture models of liver steatosis

Abstract

Normothermic perfusion provides a means to rescue steatotic liver grafts including by pharmacological defatting. In this study, we tested the potential of new drug combinations to trigger defatting in three human culture models, primary hepatocytes with induced steatosis or isolated from steatotic liver, and precision-cut liver slices (PCLS) of steatotic liver. Forskolin, L-carnitine and a PPARα agonist, all were combined with rapamycin, an immunosuppressant that induces autophagy, in a D-FAT cocktail. D-FAT was tested alone or in combination with necrosulfonamide, an inhibitor of mixed lineage kinase domain-like involved in necroptosis. Within 24 hours in all three models, D-FAT induced a decrease in triglyceride content by 30%, attributable to an up-regulation of genes involved in free fatty acid β-oxidation and autophagy, and a down-regulation of those involved in lipogenesis. Defatting was accompanied by a decrease in endoplasmic reticulum stress and in the production of reactive oxygen species. The addition of necrosulfonamide increased the efficacy of defatting by 8%-12% in PCLS, with a trend towards increased autophagy. In conclusion, culture models notably PCLS are insightful to design strategies of liver graft rescue. Defatting can be rapidly achieved by combinations of drugs targeting mitochondrial oxidative metabolism, macro-autophagy, and lipogenesis.