Fig 1: Proteasome inhibitors affect hepatic connexin (CX) 32 levels differently, depending on the drug used. The inhibitor MG132 (5 mg/kg) was injected twice: first at 12 h and then at 1 h prior to the administration of APAP. (A) Elevated CX32 protein levels after 12 h of MG132 treatment are demonstrated by western blot analysis (upper panel), with results quantified in the lower panel (n=6). 2-Aminoethyl diphenylborinate (2-APB) (20 mg/kg), a gap junction inhibitor, was injected 1 h before a second MG132 administration, and APAP was then intraperitoneally injected after 2 h. The mice were sacrificed at 6 h after the APAP injection. (B) Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were measured (n=6). (C) Decreased CX32 protein levels after bortezomib (1 mg/kg) treatment for 12 h are illustrated by western blot analysis (upper panel), and results are quantified in the lower panel (n=6). (D) RT-qPCR analysis of CX32 and CX43 mRNA was performed at the indicated times after bortezomib administration (n=6). Values are expressed as the means ± SEM. Data are representative of six independent experiments that provided similar results. *p<0.05, **p<0.01 and ***p<0.001.