RT Journal Article SR Electronic T1 Knockdown of LncRNAs HNF1α-AS1 and HNF4α-AS1 Alters Susceptibility of Acetaminophen-induced Cytotoxicity in HepaRG Cells JF Molecular Pharmacology JO Mol Pharmacol FD American Society for Pharmacology and Experimental Therapeutics SP mol.119.118778 DO 10.1124/mol.119.118778 A1 Liming Chen A1 Pei Wang A1 Jose E. E. Manautou A1 Xiao-bo Zhong YR 2020 UL http://molpharm.aspetjournals.org/content/early/2020/02/06/mol.119.118778.abstract AB Acetaminophen (APAP) is a commonly used over-the-counter drug for its analgesic and antipyretic effects. However, APAP overdose leads to severe APAP-induced liver injury (AILI) even death due to accumulation of N-acetyl-p-benzoquinone imine (NAPQI), the toxic metabolite of APAP generated by cytochrome P450s (CYPs). Long non-coding RNAs HNF1α antisense RNA 1 (HNF1α-AS1) and HNF4α antisense RNA 1 (HNF4α-AS1) are regulatory RNAs involved in the regulation of CYPs expression in both mRNA and protein levels. This study aims to determine the impact of HNF1α-AS1 and HNF4α-AS1 on AILI. Small hairpin RNAs (shRNAs) were used to knockdown HNF1α-AS1 and HNF4α-AS1 in HepaRG cells. Knockdown of these lncRNAs altered APAP-induced cytotoxicity indicated by MTT and LDH assays. Specifically, HNF1α-AS1 knockdown decreased APAP toxicity with increased cell viability and decreased LDH release, whereas HNF4α-AS1 knockdown exacerbated APAP toxicity with opposite effects in the MTT and LDH assays. Alterations on gene expression by knockdown of HNF1α-AS1 and HNF4α-AS1 were examined in several APAP metabolic pathways, including CYP1A2, 2E1, 3A4, UGT1A1, 1A9, SULT1A1, GSTP1, and GSTT1. Knockdown of HNF1α-AS1 decreased mRNA expression of CYP1A2, 2E1, and 3A4 by 0.71-fold, 0.35-fold, and 0.31-fold, respectively, while knockdown of HNF4α-AS1 induced mRNAs of CYP1A2, 2E1 and 3A4 by 1.3-fold, 1.95-fold, and 1.9 fold, respectively. The changes were also observed in protein levels. Knockdown of HNF1α-AS1 and HNF4α-AS1 had limited effects on the mRNA expression of UGT1A1, 1A9, SULT1A1, GSTP1, and GSTT1. Altogether, our study suggests that HNF1α-AS1 and HNF4α-AS1 affected AILI mainly through alterations of CYP-mediated APAP biotransformation in HepaRG cells, indicating an important role of the lncRNAs in AILI.SIGNIFICANCE STATEMENT The current research identified two lncRNAs, HNF1α-AS1 and HNF4α-AS1, which were able to affect susceptibility of AILI in HepaRG cells, possibly through regulating the expression of APAP-metabolizing P450 enzymes. This discovery added new factors, lncRNAs, which can be used to predict P450-mediated drug metabolism and drug-induced toxicity.