Animal models

C57BL6/J WT mice were purchased from Janvier and Mlxipl-deficient mice on C57BL6/J background (Chrebp^−/− - mice) were purchased from Jackson Laboratories. Animal studies with these mice were carried out in Hamburg and were approved by the Animal Welfare Officers at University Medical Center Hamburg-Eppendorf and the Behörde für Gesundheit und Verbraucherschutz Hamburg (N028/2020, date of approval: 2020/06/17; N017/2021 date of approval: 2021/04/13). Fasn^R1812W mice on C57BL6/J background were generated as described before⁴⁶. Studies with these mice were performed at Washington University and were approved by the institutional Animal Studies Committee. As data derived from human NASH patients was collected in male and female participants, animal experiments were performed in male and female mice (as indicated in the figure legends). Routinely, age matched (8–20 weeks) mice were kept in single cages in climate chambers (Memmert) with ad libitum access to regular chow diet (Altromin, 1329 P) and water. Mice were housed at room temperature (22 °C) with a day and night cycle of 12 h each and a humidity of 50%. FASN inhibition and DHA supplementation were performed after two weeks of high-fat diet (EF Bio-Serv F3282, Ssniff®, 60% fat) feeding via DHA supplemented high-fat diet (2.2%) at room temperature and daily oral gavage of 3 mg/kg TVB 3664 in 30% PEG400 for 7 days. Incorporation of radioactive fatty acids into VLDL was performed by body weight adapted i.v. injection of a solution containing 1 ml of 0.5 mM albumin conjugated with radioactive fatty acids (0.37MBq ¹⁴C-DHA, 0.185 MBq ³H-palmitate or 0.3 MBq ³H-oleate per 10 mice) into wild-type or Chrebp^−/− mice, which additionally received a body weight adapted dose (5 µl/g) of tyloxapol (10% in NaCl) to inhibit lipases as described before⁵⁷. Blood for EDTA plasma measurements was collected by cardiac puncture of anaesthetized mice.