Evaluation of three-dimensional cultured HepG2 cells in a nano culture plate system: An in vitro human model of acetaminophen hepatotoxicity

Overdoses of acetaminophen (paracetamol,n-acetyl-p-aminophenol; apap) cause severe liver injury,yet there is no common or high throughput in vitro human apap model. this study examined the characteristics and usefulness of hepg2 cells grown in a nano culture plate (ncp) system,a three-dimensional culture method,as an in vitro human model for apap-induced hepatotoxicity. the ncp-cultured hepg2 cells showed higher expression of mrna and protein levels of cytochrome p450 2e1,which metabolizes apap to a toxic metabolite,apap-cysteine adduct formation,and higher sensitivity against apap-induced cell injury compared with conventionally cultured cells. we demonstrated that treatment of apap in ncp-cultured hepg2 cells shows key mechanistic features of apap-induced hepatotoxicity,such as decreases in intracellular glutathione and mitochondrial membrane potential,activation of jnk,and cellular injury; and pharmacological agents,such as cyclosporine a (a mitochondrial permeability transition inhibitor) and sp600125 (a jnk inhibitor),prevented cell injury induced by apap exposure. in addition,the antidote of apap-induced hepatotoxicity,n-acetylcysteine,could attenuate cellular injury induced by apap in ncp-cultured hepg2 cells. we suggest that cellular injury induced by apap treatment using an ncp-hepg2 system is a useful human model to study mechanisms and screen drug candidates of apap-induced hepatotoxicity. © 2014 the japanese pharmacological society.