Spontaneous hepatitis in Tak1ΔHEP mice. (A–C) WT (n = 10), Tak1ΔHEP (n = 10), and Kupffer cell–depleted Tak1ΔHEP mice (n = 3) were analyzed at age 1 month. Kupffer cells were depleted by liposomal clodronate injection 24 h before death. (A) H&E staining. (B) Hepatic mRNA expression of inflammatory genes including F4/80, Tnf, Il6, and Il1b, determined by real-time PCR. (C) Phospho-JNK and JNK expression in livers from WT, Tak1ΔHEP mice, and Kupffer cell–depleted Tak1ΔHEP mice assessed by immunoblot analysis. (D) Immunohistochemistry for phospho-JNK in Tak1ΔHEP liver. Black and white arrows indicate JNK activation in nonparenchymal cells and hepatocytes, respectively. Data are reported mean ± SEM. *P < .05; **P < .01. (Scale bar: 20 μm in A and D.)