Characterization of Triptolide-Induced Hepatotoxicity by Imaging and Transcriptomics in a Novel Zebrafish Model

Abstract

Triptolide is a vine extract used in traditional Chinese medicines and associated with hepatotoxicity. In vitro data suggest that inhibition of RNA synthesis may be the mechanism of toxicity. For studying drug-induced liver injury the zebrafish has experimental, practical and financial advantages compared with rodents. The aim of this study was to explore the mechanism of triptolide toxicity using zebrafish as the model system. The effect of triptolide exposure on zebrafish larvae was determined with regard to mortality, histology, expression of liver specific microRNA-122 and liver volume. Fluorescent microscopy was used to track toxicity in the Tg(-2.8lfabp:GFP)as3 zebrafish line. Informed by microscopy, RNA-sequencing was used to explore the mechanism of toxicity. Triptolide exposure resulted in dose-dependent mortality, a reduction in the number of copies of microRNA-122 per larva, hepatocyte vacuolation, disarray and oncotic necrosis, and a reduction in liver volume. These findings were consistent across replicate experiments. Time-lapse imaging indicated the onset of injury was 6 h after the start of exposure, at which point, RNA-sequencing revealed that 88% of genes were down-regulated. Immune response associated genes were up-regulated in the triptolide-treated larvae including nitric oxide synthase. Inhibition of nitric oxide synthase increased mortality. Triptolide induces hepatotoxicity in zebrafish larvae. This represents a new model of drug-induced liver injury that complements rodents. RNA sequencing, guided by time-lapse microscopy, revealed early down-regulation of genes consistent with previous invitro studies, and facilitated the discovery of mechanistic inflammatory pathways.

Triptolide‐induced hepatotoxicity via apoptosis and autophagy in zebrafish

“…It was reported that TP has antiangiogenic (He et al, ), antiproteinuric (Wang et al, ) and antitumor (Gao et al, ) activities in the zebrafish. It has also been reported that exposure to TP was dose‐dependent for mortality, hepatocyte vacuolation, disarray and oncotic necrosis in zebrafish (Vliegenthart et al, ). It has been suggested that TP‐induced hepatotoxicity could be copied in a zebrafish model.…”

“…It has been suggested that TP‐induced hepatotoxicity could be copied in a zebrafish model. Immune response‐associated genes, including nitric oxide synthase, were upregulated, which indicated that activation of the inflammatory signaling pathway might play an important role in TP‐induced hepatotoxicity (Vliegenthart et al, ). However, the roles of apoptosis and autophagy in TP‐induced zebrafish hepatotoxicity were still unclear.…”

High‐content analysis boosts identification of the initial cause of triptolide‐induced hepatotoxicity

“…During the last decade, many studies have been carried out to uncover the mechanism of TP‐induced liver injury or hepatotoxicity, particularly at the cellular level. Various new omics technologies, including transcriptomics and metabolomics, have even been adopted (Vliegenthart et al, ; Zhao et al, ). However, the mechanistic explanations for TP‐induced hepatotoxicity still focus on common phenomena or the endpoint events of cell fate, such as oxidative stress, inflammatory reaction, cell cycle arrest and apoptosis (Cao et al, ; Fu et al, ; Meng et al, ; Oliveira et al, ).…”

CYP2E1 and miRNA‐378a‐3p contribute to acetaminophen‐ or tripterygium glycosides‐induced hepatotoxicity

“…Emerging data suggested that microRNAs (miRs) were implicated in APAP-or TP-induced liver injury. 31,34 miR-378a-3p was reported to be involved in the pathogenesis of various liver diseases. [35][36][37][38][39] And CYP2E1 is specifically regulated by miR-378a-3p via interactions with the 3′-untranslated regions (3′-UTR) of its mRNA transcript.…”