Effect of tauroursodeoxycholate on actin filament alteration induced by cholestatic agents. A study in isolated rat hepatocyte couplets

• Published in: Journal of hepatology Vol. 19; no. 3; pp. 367 - 376
• Main Authors: Thibault, Nancy, Maurice, Michèle, Maratrat, Michel, Cordier, André, Feldmann, Gérard, Ballet, François
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 01.11.1993; Elsevier
• Subjects: Actin; Actins - drug effects; Actins - ultrastructure; Animals; Bile acids and salts; Bile Acids and Salts - pharmacology; Bile Ducts - drug effects; Bile Ducts - ultrastructure; Biological and medical sciences; Cholestasis; Cholestasis - chemically induced; Digestive system; Erythromycin estolate; Erythromycin Estolate - pharmacology; Fluorescent Dyes; Hepatocyte couplets; In Vitro Techniques; Isomerism; Liver - cytology; Liver - drug effects; Male; Medical sciences; Microscopy, Electron; Models, Biological; Phalloidine - pharmacology; Pharmacology. Drug treatments; Rats; Rats, Sprague-Dawley; Scanning laser cytometry; Taurodeoxycholic Acid - pharmacology; Taurolithocholate; Taurolithocholic Acid - pharmacology; Tauroursodeoxycholate; CF; DMSO; Tauroursodeoxycholate; IRHC; TUDC; Scanning laser cytometry; ACAS; TLC; ERY; TC; Hepatocyte couplets; FITC; TF; Actin; Taurolithocholate; Erythromycin estolate; FCS; PH; Bile acids and salts; Cholestasis; CFDA; Cell culture; Rat; Bile salt; Rodentia; Actins; Biliary tract disease; Electron microscopy; In vitro; Macrolide; Biological activity; Fluorescence spectrometry; Pathology; Vertebrata; Experimental disease; Mammalia; Hepatocyte; Bile acid; Animal; Cholostasis; Digestive diseases
• ISSN: 0168-8278; 1600-0641
• DOI: 10.1016/S0168-8278(05)80544-6

The mechanism of the protective effect of ursodeoxycholic acid in cholestatic liver diseases remains unclear. Since there is evidence that alterations in the pericanalicular actin microfilament network play a major role in cholestasis, the aims of this study were (a) to determine the effect of the cholestatic agents, taurolithocholate (TLC) and erythromycin estolate (ERY), on F-actin distribution in isolated rat hepatocyte couplets and (b) to assess the effect of tauroursodeoxycholate (TUDC) and taurocholate on the modifications induced by these two compounds. F-actin was stained with fluorescein-isothiocyanate phalloidin and fluorimetric measurements were performed using a scanning laser cytometer ACAS 570. F-actin distribution was assessed in the couplets by the ratio of the pericanalicular area fluorescence/total couplet fluorescence (CF/TF). At non-cytotoxic concentrations, TLC (50, 100 μM) and ERY (10, 50, 100 μM) induced a significant accumulation of F-actin around the bile canaliculus as indicated by increased fluorescence in the pericanalicular area and by the increased CF/TF ratio compared with the controls. Electron microscopy studies showed significant alterations in bile canaliculi microvilli in couplets treated with 100 μM TLC. Only a few canaliculi showed an increase in pericanalicular microfilaments after treatment with 100 μM ERY. As assessed by scanning laser cytometry, TUDC prevented changes in F-actin distribution when it was added to the medium with taurolithocholate or erythromycin estolate at equimolar concentrations. However, the morphological changes observed by electron microscopy after treatment with TLC were not modified by co-treatment with TUDC. Taurocholate was ineffective. We conclude that (a) abnormalities of pericanalicular F-actin microfilaments occur in two different models of cholestasis, (b) tauroursodeoxycholate prevents the accumulation of pericanalicular F-actin detected by scanning laser cytometry but not the morphological changes of the canaliculus observed by electronic microscopy. Therefore, in these experimental conditions, the protective effect of TUDC appears to be partial.