The peroxisome proliferator-activated receptor-α (PPARα) hepatocyte-specific knockout (PparaHepKO) mice develop hepatic inflammation on high-fat diet (HFD). A: H&E staining in livers from PPAR wild-type (Pparafl/fl) and PparaHepKO mice on normal fat diet (NFD) and HFD and inflammation score. Yellow arrows, PparaHepKO had focal-to-mild lobular inflammation on 100% of the HFD mice tested. B and C: biochemical measurement of hepatic triglyceride levels. Measurement of hepatic immune gene expression in NFD and HFD in Pparafl/fl and PparaHepKO mice for Cd20 and Cd3 (B) and macrophage markers Adgre1, Tnfa, Nos2, and Arg1 (C). Values are means ± SE; *P < 0.05 vs. NFD Pparafl/fl; #P < 0.05 vs. HFD Pparafl/fl; ^P < 0.05 vs. NFD PparaHepKO. A: n = 13 and 8, Pparafl/fl NFD, HFD; n = 6 and 8, PparaHepKO NFD, HFD. B and C: n = 13 and 7, Pparafl/fl NFD, HFD; n = 6 and 8, PparaHepKO NFD, HFD. n, number of mice. All circles, NFD; all squares, HFD.