3B). Additionally,

the mRNA levels find more of the genes encoding basolateral bile acid excretion transporters (ATP-binding cassette subfamily C member 1/4/5 [Abcc1/4/5, also known as Mrp1/4/5] and organic solute transporter β [Ostb]) were markedly increased in MCD diet–treated mice (Fig. 3B). The expression of canalicular bile acid excretion transporters (Abcc2 [also known as Mrp2] and ATP-binding cassette subfamily B member 11 [Abcb11, also known as Bsep]) was unchanged (Fig. 3B). Furthermore, mRNA encoding arachidonate 12-lipoxygenase (Alox12), involved in 12-HETE metabolism, was increased by MCD diet treatment (Fig. 3C). All these changes in the mRNA levels were also detected in mice treated with the MCD diet for 2 weeks (Supporting Fig. 2). To further clarify the association between the development of NASH and the changes in serum metabolites and related genes, mice were fed an MCD diet for 3 days, 1 week, and 2 weeks, and the changes in serum metabolites and related gene expression were investigated. Serum ALT levels and hepatic TG contents were increased as early as 3 days after starting MCD treatment and further increased after 2 weeks of treatment (Supporting Fig. 3). The increases

in serum ALP levels followed those in serum ALT levels, and both were correlated with altered hepatic pathologies (Supporting Fig. 3). Although the changes in serum LPC and 12-HETE became greater in a time-dependent manner, serum tauro-β-muricholate Dabrafenib order and taurocholate learn more were rapidly increased in mice treated with the

MCD diet for 2 weeks (Supporting Fig. 4A). Serum LPC levels were decreased with the increases in hepatic expression of Lpcat1-4 (Supporting Fig. 4). Indeed, serum concentrations of 16:0-, 18:0-, and 18:1-LPC demonstrated a strong negative correlation with hepatic mRNAs encoding Lpcat1-4, especially Lpcat1/2/4 (Supporting Fig. 5A). Increased tauro-β-muricholate and taurocholate levels paralleled the increases in Abcc1/4/5 and Ostb mRNAs and the decreases in mRNAs encoding Slc10a1 and Slco1a1 (Supporting Fig. 4). These bile acid levels were strongly correlated with Abcc1 mRNA levels (Supporting Fig. 5B). However, serum 12-HETE levels did not correlate with hepatic Alox12 mRNA levels (Supporting Fig. 5C). Because LPC is a precursor of PC and PC is known to be an important endogenous compound associated with bile acid excretion and maintenance of choline homeostasis,21, 22 it is reasonable to consider that the decreased LPC and the increased tauro-β-muricholate and taurocholate in serum simply result from dietary choline deficiency. Therefore, supplementation of methionine or choline to the MCD diet was examined. Methionine supplementation to the MCD diet, i.e.