Rho-kinase/myosin light chain kinase pathway plays a key role in the impairment of bile canaliculi dynamics induced by cholestatic drugs

• Published in: Scientific reports Vol. 6; no. 1; p. 24709
• Main Authors: Sharanek, Ahmad, Burban, Audrey, Burbank, Matthew, Le Guevel, Rémy, Li, Ruoya, Guillouzo, André, Guguen-Guillouzo, Christiane
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 12-05-2016; Nature Publishing Group
• Subjects: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine - analogs & derivatives; 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine - pharmacology; 631/1647; 631/1647/328; Bile; Bile Acids and Salts - metabolism; Bile Canaliculi - drug effects; Bile Canaliculi - physiology; Bile ducts; Cardiac Myosins - metabolism; Cell Survival - drug effects; Cells, Cultured; Chlorpromazine; Chlorpromazine - pharmacology; Cholestasis; Cyclosporine - pharmacology; Cyclosporins; Deoxycholic acid; Dephosphorylation; Gallbladder diseases; Hepatocytes; Hepatocytes - cytology; Hepatocytes - drug effects; Hepatocytes - metabolism; Human health and pathology; Humanities and Social Sciences; Humans; Hépatology and Gastroenterology; Isothiocyanate; Life Sciences; Liver; Microscopy, Fluorescence; multidisciplinary; Myosin; Myosin Light Chains - metabolism; Myosin Type II - metabolism; Myosin-light-chain kinase; Myosin-Light-Chain Kinase - metabolism; Pharmaceutical sciences; Pharmacology; Phosphorylation; Phosphorylation - drug effects; Rho-associated kinase; rho-Associated Kinases - metabolism; Rocks; Science; Signal Transduction - drug effects; Time-Lapse Imaging; Zonula Occludens-1 Protein - metabolism
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep24709

Intrahepatic cholestasis represents a frequent manifestation of drug-induced liver injury; however, the mechanisms underlying such injuries are poorly understood. In this study of human HepaRG and primary hepatocytes, we found that bile canaliculi (BC) underwent spontaneous contractions, which are essential for bile acid (BA) efflux and require alternations in myosin light chain (MLC2) phosphorylation/dephosphorylation. Short exposure to 6 cholestatic compounds revealed that BC constriction and dilation were associated with disruptions in the ROCK/MLCK/myosin pathway. At the studied concentrations, cyclosporine A and chlorpromazine induced early ROCK activity, resulting in permanent MLC2 phosphorylation and BC constriction. However, fasudil reduced ROCK activity and caused rapid, substantial and permanent MLC2 dephosphorylation, leading to BC dilation. The remaining compounds (1-naphthyl isothiocyanate, deoxycholic acid and bosentan) caused BC dilation without modulating ROCK activity, although they were associated with a steady decrease in MLC2 phosphorylation via MLCK. These changes were associated with a common loss of BC contractions and failure of BA clearance. These results provide the first demonstration that cholestatic drugs alter BC dynamics by targeting the ROCK/MLCK pathway; in addition, they highlight new insights into the mechanisms underlying bile flow failure and can be used to identify new predictive biomarkers of drug-induced cholestasis.