Pathobiology and experimental therapeutics in hepatocellular cholestasis: lessons from the hepatocyte couplet model

Abstract

Preparations of isolated liver cells, either freshly prepared or in culture, have been available for many years; however, because they lack the polarization of the cell in the tissue, their application to the study of processes involved in bile formation has been very limited. The hepatocyte couplet model offers a unique opportunity to study in vitro the intracellular processes involved: not only the physiology and pathophysiology of bile formation, but also the corresponding structural and molecular disturbances underlying different experimental models of cholestasis. In this review we describe the experimental data generated from this model in our laboratory over a period of years, including application of hepatocyte couplets to the study of cytoskeletal changes within the hepatocyte and mechanisms of hepatoprotection in experimentally induced, clinically relevant models of intrahepatic cholestasis.

Use ofin vitrotransporter assays to understand hepatic and renal disposition of new drug candidates

“…The advantage of the couplets is that these are polarised and have a sinusoidal or basolateral membrane interacting with the media/buffer and an apical bile canaliculus, which is the sealed lumen between the two adjacent hepatocytes [164]. Rat couplets have been used to evaluate bile transport and BSEP function by monitoring taurocholate transport [165,166], canalicular transport of the organic cation, daunorubicin [167], electroneutral uptake and electrogenic secretion of the fluorescent bile salt, N-(7-(4-nitrobenzo-2-oxa-1,3-diazol))-7β-amino-3α,12α-dihydroxy-5β-cholan-24-oyl-2′-aminoethanesulfonate [168] and inhibition of P-gp by immunosuppressants [169].…”

“…The hepatocyte couplet model allows for the evaluation of both drug uptake and biliary elimination [162][163][164]. The advantage of the couplets is that these are polarised and have a sinusoidal or basolateral membrane interacting with the media/buffer and an apical bile canaliculus, which is the sealed lumen between the two adjacent hepatocytes [164].…”

Sandwich-cultured rat hepatocytes as an in vitro model to study canalicular transport alterations in cholestasis

“…The need to study these rapid changes in hepatocyte transport function in a rapid and reproducible manner, avoiding the use of experimental animals, has encouraged the development of in vitro, polarized models of hepatocellular transport. For example, isolated rat hepatocyte couplets (IRHCs) have been successfully used since the early 1980s to study structural alterations (cytoskeleton, tight junctions), impairment in function and localization of transporters induced by toxic and/or cholestatic compounds, and their prevention by hepatoprotective compounds (Coleman and Roma 2000;Milkiewicz et al 2002b;Roma et al 2008). Administration of either the endogenous estradiol Abstract At present, it has not been systematically evaluated whether the functional alterations induced by cholestatic compounds in canalicular transporters involved in bile formation can be reproduced in sandwich-cultured rat hepatocytes (SCRHs).…”