Fig. 2. Influence of Bach1 ablation on hepatic lipid metabolism. (A) Liver sections from wild type (A and B) and Bach1−/− mice (C and D) fed either regular chow (left panels) or MCD diet (right panels) were processed for haematoxylin & eosin (HE) staining. (original magnification 200×). (B) Hepatic triglyceride concentrations in wild type (open bars) and Bach1−/− (closed bars) mice (n = 5/each group) were determined after feeding either regular chow or MCD diet. (C) Hepatic mRNA expressions of PPARα and MTP were quantified (n = 5/each group) by quantitative realtime PCR. *p<0.05, regular chow vs MCD diet. †p<0.05, wild type vs Bach1−/− mice. triglyceride content increased by 6-fold in wild type mice following MCD diet feeding whereas values remained unchanged in Bach1−/− mice. To further explore the effect of Bach1 ablation, mRNA expressions of key genes involving in hepatic lipid metabolism were investigated. This revealed marked down-regulation of PPARα and MTP in wild type mice whereas there were no signifi- cant changes in Bach1−/− mice, suggesting that fatty acid utiliza- tion and excretion were preserved in Bach1−/− mice on MCD diet. Protective effect of Bach1 ablation on MCD dietinduced liver injury. Feeding of MCD diet increased serum ALT levels in wild type mice at 4 and 8 weeks whereas it remained the basal level in Bach1−/− mice, implying protective effect of Bach1 abla- tion against liver injury (Fig. 3A). Consistent with these findings, hepatic MDA concentration which reflects oxidative damage elicited by lipid peroxidation in the liver remained unchanged in Bach1−/− mice following MCD diet (Fig. 3B). This was in marked M. Inoue et al. J. Clin. Biochem. Nutr. | March 2011 | vol. 48 | no. 2 | 163 ©2011 JCBN