From the Cover: MechanisticInsights in Cytotoxic and Cholestatic Potential of the Endothelial Receptor Antagonists Using HepaRG Cells

Toxicol Sci. 2017 Jun 1;157(2):451-464. doi: 10.1093/toxsci/kfx062.


Several endothelin receptor antagonists (ERAs) have been developed for the treatment of pulmonary arterial hypertension (PAH). Some of them have been related to clinical cases of hepatocellular injury (sitaxentan [SIT]) and/or cholestasis (bosentan [BOS]). We aimed to determine if ambrisentan (AMB) and macitentan (MAC), in addition to BOS and SIT, could potentially cause liver damage in man by use of human HepaRG cells. Our results showed that like BOS, MAC-induced cytotoxicity and cholestatic disorders characterized by bile canaliculi dilatation and impairment of myosin light chain kinase signaling. Macitentan also strongly inhibited taurocholic acid and carboxy-2',7'-dichlorofluorescein efflux while it had a much lower inhibitory effect on influx activity compared to BOS and SIT. Moreover, these three drugs caused decreased intracellular accumulation and parallel increased levels of total bile acids (BAs) in serum-free culture media. In addition, all drugs except AMB variably deregulated gene expression of BA transporters. In contrast, SIT was hepatotoxic without causing cholestatic damage, likely via the formation of reactive metabolites and AMB was not hepatotoxic. Together, our results show that some ERAs can be hepatotoxic and that the recently marketed MAC, structurally similar to BOS, can also cause cholestatic alterations in HepaRG cells. The absence of currently known or suspected cases of cholestasis in patients suffering from PAH treated with MAC is rationalized by the lower therapeutic doses and Cmax, and longer receptor residence time compared to BOS.

Keywords: HepaRG cells; bile canaliculi; cholestasis; endothelin receptor antagonists; hepatotoxicity.

MeSH terms

  • Bile Acids and Salts / metabolism
  • Bile Canaliculi / drug effects
  • Bile Canaliculi / metabolism
  • Bile Canaliculi / pathology
  • Cardiac Myosins / metabolism
  • Cell Culture Techniques
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Cholestasis / chemically induced*
  • Cholestasis / metabolism
  • Cholestasis / pathology
  • Dose-Response Relationship, Drug
  • Endothelin Receptor Antagonists / toxicity*
  • Hepatocytes / drug effects*
  • Hepatocytes / metabolism
  • Hepatocytes / pathology
  • Humans
  • Myosin Light Chains / metabolism
  • Receptors, Endothelin / metabolism*


  • Bile Acids and Salts
  • Endothelin Receptor Antagonists
  • Myosin Light Chains
  • Receptors, Endothelin
  • myosin light chain 2
  • Cardiac Myosins