3E and Supporting Fig. 4A). Only slight changes in the transcription factors and the phosphorylation of eukaryotic translation initiation factor 2α (eIF2α) were detected in the WT mice that were fed a low dose of alcohol, and this was consistent with the mild fat accumulation observed previously. However, in the LGKO liver, most of these factors were altered. Alcohol feeding had either enhancing or reducing effects on the tested ER stress factors (Fig. 3E and Supporting Fig. 4). In LGKO mice,

alcohol further increased the expression of nuclear SREBP1c, ChREBP, and C/EBPα and increased messenger RNA (mRNA) levels of Insig2. Alcohol decreased the levels of ATF6, Gadd34, R428 mouse Insig1, the ATF6 transcriptional Ibrutinib target endoplasmic reticulum protein 57 (ERp57), and Derl3. Alcohol had no further effects on spliced X-box binding protein 1 (sXbp1), CHOP, or ATF4, the levels of which were already increased after the GRP78 deletion. Alcohol had no effects on PPARα. CYP2E1 levels were increased in response to alcohol, but the GRP78 deletion had no apparent effect on CYP2E1 expression. The levels of stearoyl coenzyme A desaturase 1, fatty acid synthase, and PPARγ were increased by alcohol or the GRP78 deletion alone and were increased further in alcohol-fed

LGKO mice. This indicates that interplay between ER stress and alcohol feeding aggravates fat accumulation in the liver (Fig. 3F). To determine whether the liver Grp78 deletion worsens nonalcoholic steatosis, we fed the mice an HFD. The HFD induced moderate fatty liver injury (a 1.5-fold increase

in LGKO mice versus pair-fed controls) within 6 weeks, and there were no significant differences in the HFD-induced liver injuries of WT and WK mice (Fig. Dapagliflozin 4A-C). GRP78 and GRP94 were increased in the WK mice in response to the HFD, which may have compensated for the heterozygous loss of Grp78 in the liver (Fig. 4D). A slight activation of ATF6 was detected in LGKO mice not fed the HFD, and an apparent activation was observed in both WT mice and LGKO mice that were fed the HFD (Fig. 4E). In comparison with HFD-fed WT mice, the HFD doubled both hepatic triglyceride and ALT levels in LGKO mice, and this was accompanied by greater GRP94 induction and eIF2α phosphorylation, which indicated a severe ER stress response in HFD-fed LGKO mice. HIV-infected patients receiving anti-HIV therapeutics with HIV PIs often concomitantly consume or abuse alcohol.13 To address whether HIV PIs alone or in combination with alcohol trigger ER stress in the mouse liver, we treated mice with alcohol and/or ritonavir and lopinavir by gavage. Neither liver injury (according to serum ALT and AST levels) nor an ER stress response was detected when the animals were treated with the acute administration of alcohol alone or with a combination of ritonavir and lopinavir for 16 hours (data not shown).