Acetaminophen (APAP) hepatocyte toxicity is associated with increased translocation of glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) to the nucleus.

Abstract

Previously, we have described that APAP intoxication induces nuclear translocation of GAPDH in rat liver. Recently, GAPDH nuclear traslocation was highlighted as a mediator of cell death.AimTo test if GAPDH nuclear translocation is associated with loss of viability of rat hepatocytes exposed to APAP. M&M: Rat isolated hepatocytes were exposed to different doses of APAP (0‐50 mM), for 24 h, in the absence or presence of RAS (10 µM), an inhibitor of GAPDH nuclear translocation. Cell viability was evaluated by the MTT assay and IC50 was calculated. Nuclear and cytosolic GAPDH, cytosolic cytochrome c, and mitochondrial BAX contents were evaluated by WB in hepatocytes treated with APAP (30 mM) and/or RAS (10 µM) for 24 h.ResultsIC50: RAS: 40.0±8.5 mM*; Control: 18.5±0.6 mM. Nuclear/Nuclear+cytosolic GAPDH expression ratio: APAP: 155±29*$; APAP‐RAS: 26±10*; RAS: 42±17*; C: 100±5. Cytosolic cytochrome c: APAP: 320±7.5*$; APAP‐RAS: 31±22; RAS: 19±32; C: 100±59. Mitochondrial BAX: APAP: 468±57*♦; APAP‐RAS: 342±45*♦; RAS: 152±81; C: 100±59. WB data are expressed as % of control. * P<0.05 vs C; $ P<0.05 vs RAS and APAP‐RAS. ♦ P<0.05 vs RAS.ConclusionAPAP acute intoxication increased GAPDH nuclear translocation in isolated hepatocytes. RAS blockage of such traslocation was associated with prevention in alteration of apoptotic/necroptotic marker (cytochrome C) and consequently with increased survival of the cells to APAP cytotoxicity. The data strongly suggest a link between APAP liver toxicity and GAPDH translocation.