Overexpression and nuclear translocation of glyceraldehyde‐3‐phosphate dehydrogenase in acetaminophen acutely intoxicated rats

Abstract

The mechanism of acetaminophen (AAP) hepatotoxicity involves glutathione depletion, oxidative stress and mitochondrial dysfunction leading to necrosis. Recently, glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) was highlighted as a mediator of cell death.AimTo evaluate GAPDH expression and subcellular distribution in liver of AAP acute intoxicated rats.M&MMale Wistar rats were injected i.p. with 1 g/kg b.w. of AAP (AAP group) or vehicle (C group) (n=4). After 24 h, liver GAPDH expression (mRNA and protein) was studied by RT‐PCR and Western‐Blot (WB). Nuclear, mitochondrial, and cytosolic GAPDH content was evaluated in hepatic subcellular fractions by WB. Results were expressed as mean±SD and statistically analized with Student‐t‐test (* p<0.05 vs C).ResultsGAPDH mRNA (AAP:408±221*; C:100±26) and protein expression (AAP:292±127*; C:100±7) were significantly increased in treated rats. Subcellular distribution of GAPDH changed for nucleus (AAP:232±95*; C:100±49) but not for mitochondrial and cytosolic fractions.ConclusionAAP acute intoxication increased GAPDH expression due to a transcriptional mechanism, which questions its use as a housekeeping gene for either RT‐PCR or WB studies. Under AAP overdose, the GAPDH increase its content in the nucleus sugesting a role in AAP toxicity.