Changes in Transporters and Metabolizing Enzymes in the Livers of Rats with Bile Duct Ligation

Purpose: Bile duct ligation (BDL) in experimental animals is widely used as an animal model of liver cholestasis and fibrosis. The transcriptional process and plasma membrane localization of transporters are regulated by nuclear receptors and scaffold proteins, respectively. However, the detailed changes of these factors in the livers of BDL rats remain unclear. To clarify the effects of BDL on the levels of transporters and metabolizing enzymes, nuclear receptors, and scaffold proteins, we investigated changes in mRNA and protein levels of livers from BDL rats. Methods: Membrane proteins and microsomes were prepared from rats with BDL. The mRNA levels of transporters and nuclear receptors in livers of control and BDL rats were examined by real-time reverse transcription polymerase chain reaction. The protein levels of transporters, metabolizing enzymes and scaffold proteins in membrane proteins and microsomes were determined by liquid chromatography-tandem mass spectrometry-based targeted proteomics. Results: Mdr1a mRNA was significantly decreased at 1 and 2 weeks of BDL. The mRNA levels of MRP2 were significantly decreased. The mRNA levels of nuclear receptors were significantly decreased in livers of 1-week BDL rats. The protein levels of P-gp were significantly increased by BDL. Regarding scaffold proteins, the protein levels of ezrin, moesin and EBP50 were significantly decreased at 2 weeks of BDL. The protein levels of radixin were significantly increased at 1 week of BDL. In 1-week BDL rats, the protein levels of metabolizing enzymes such as CYP and UGT were significantly decreased. Conclusions: This study reports the comprehensive changes of transporters, metabolizing enzymes, nuclear receptors, and ezrin/radixin/moesin proteins in the livers of BDL rats. The expression levels of nuclear receptors and radixin that regulate the transcription and localization of CYP and/or transporters were decreased by BDL.

Download Full-text

Increased Expression of Adherens Junction Components in Mouse Liver following Bile Duct Ligation

Biomolecules ◽

10.3390/biom9100636 ◽

2019 ◽

Vol 9 (10) ◽

pp. 636 ◽

Cited By ~ 1

Author(s):

Van Campenhout ◽

Crespo Yanguas ◽

Cooreman ◽

Gijbels ◽

Leroy ◽

...

Keyword(s):

Bile Duct ◽

Mouse Liver ◽

Bile Duct Ligation ◽

Adherens Junctions ◽

Adherens Junction ◽

Cell Junctions ◽

Tissue Architecture ◽

Fibrotic Liver ◽

Protein Levels ◽

Duct Ligation

Adherens junctions, consisting of cadherins and catenins, are a group of cell-to-cell junctions that mediate mechanistic linkage between neighboring cells. By doing so, adherens junctions ensure direct intercellular contact and play an indispensable role in maintaining tissue architecture. Considering these critical functions, it is not surprising that adherens junctions are frequently involved in disease. In the present study, the effects of bile duct ligation—a surgical procedure to experimentally induce cholestatic and fibrotic liver pathology—on hepatic adherens junctions were investigated in mice. In essence, it was found that liver mRNA and protein levels of E-cadherin, β-catenin and γ-catenin drastically increase following bile duct ligation. These results could suggest a cytoprotective role for hepatic adherens junctions following bile duct ligation.

Download Full-text

Impact of bile duct obstruction on hepatic E. coli infection: role of IL-10

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00095.2004 ◽

2006 ◽

Vol 291 (1) ◽

pp. G91-G94 ◽

Cited By ~ 6

Author(s):

D. Rohan Jeyarajah ◽

Mariusz L. Kielar ◽

Hoosein Saboorian ◽

Prameela Karimi ◽

Nicole Frantz ◽

...

Keyword(s):

Bile Duct ◽

Bacterial Growth ◽

Biliary Obstruction ◽

Bile Duct Ligation ◽

Hepatic Clearance ◽

Hepatic Necrosis ◽

E Coli ◽

Protein Levels ◽

Duct Ligation

Biliary obstruction in the setting of hepatic bacterial infection has great morbidity and mortality. We developed a novel murine model to examine the effect of biliary obstruction on the clearance of hepatic Escherichia coli infection. This model may allow us to test the hypothesis that biliary obstruction itself adversely affects clearance of hepatic infections even if the bacteria are introduced into the liver by a nonbiliary route. We ligated the bile ducts of C57BL/6 mice on days − 1, 0, or + 1, relative to a day 0 portal venous injection of E. coli. We monitored survival, hepatic bacterial growth, pathology, and IL-10 protein levels. The role of IL-10 in this model was further examined using IL-10 knockout mice. Mice with bile duct ligation at day +1 or 0, relative to portal venous infection at day 0, had decreased survival compared with mice with only portal venous infection. The impaired survival was associated with greater hepatic bacterial growth, hepatic necrosis, and increased production of IL-10. Interestingly, the transgenic knockout of IL-10 resulted in impaired survival in mice with bile duct ligation and portal venous infection. Biliary obstruction had a dramatic detrimental effect on hepatic clearance of portal venous E. coli infection. This impaired clearance is associated with increased IL-10 production. However, transgenic knockout of IL-10 increased mortality after hepatic infection.

Download Full-text

Altered hepatic localization and expression of occludin after common bile duct ligation

AJP Cell Physiology ◽

10.1152/ajpcell.1995.269.4.c1057 ◽

1995 ◽

Vol 269 (4) ◽

pp. C1057-C1062 ◽

Cited By ~ 38

Author(s):

M. B. Fallon ◽

A. R. Brecher ◽

M. S. Balda ◽

K. Matter ◽

J. M. Anderson

Keyword(s):

Bile Duct ◽

Common Bile Duct ◽

Tight Junction ◽

Bile Duct Ligation ◽

Common Bile Duct Ligation ◽

Protein Levels ◽

Duct Ligation ◽

Junction Protein ◽

Dimensional Reconstruction ◽

Surrounding Areas

Epithelial tight junctions form a regulated barrier that seals the paracellular space and prevents mixing of luminal contents with the interstitium. This barrier is composed of a group of proteins including the putative “sealing” protein occludin that appears to bind directly to a cytoplasmic junction protein, ZO-1. To study the interaction and regulation of these two components when paracellular integrity is altered, we assessed protein expression and immunofluorescent (IF) localization of ZO-1 and occludin in a rat model of hepatocyte tight junction damage induced by common bile duct ligation (CBDL). Protein levels were detected in liver by immunoblotting and IF localization by 3-dimensional reconstruction of serial 0.5-micron confocal microscopic optical sections. As previously described, ZO-1 protein levels progressively increased to threefold control levels 9 days after CBDL. In contrast, occludin protein levels decreased by 50% within 2 days after CBDL and returned to control values by 9 days. In control IF sections, ZO-1 and occludin colocalized, forming thin continuous staining outlining canaliculi. After CBDL, ZO-1 staining appeared discontinuous, and a punctate pericanalicular accumulation of signal developed around junctional areas. Occludin staining was also discontinuous after CBDL, but, in contrast to ZO-1, was not punctate and remained localized either in a linear fashion along canalicular margins or in a homogeneous fashion in immediately surrounding areas. CBDL results in changes in the expression and localization of the putative tight junction sealing protein occludin in hepatocytes that are distinct from those observed for the peripheral membrane tight junction protein ZO-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Download Full-text

Altered expression and localization of the tight junction protein ZO-1 after common bile duct ligation

AJP Cell Physiology ◽

10.1152/ajpcell.1993.264.6.c1439 ◽

1993 ◽

Vol 264 (6) ◽

pp. C1439-C1447 ◽

Cited By ~ 25

Author(s):

M. B. Fallon ◽

A. Mennone ◽

J. M. Anderson

Keyword(s):

Bile Duct ◽

Common Bile Duct ◽

Protein Expression ◽

Tight Junction ◽

Bile Duct Ligation ◽

Mrna Levels ◽

Common Bile Duct Ligation ◽

Duct Ligation ◽

Junction Protein ◽

Mrna And Protein Expression

Hepatocyte tight junctions form the intercellular barrier between bile and blood. Cholestasis due to common bile duct ligation (CBDL) results in structural changes in the tight junction (TJ) and an overt paracellular leak, although the molecular basis for these alterations is undefined. Using the epithelial isoform of the TJ protein ZO-1 (ZO-1 alpha +) as a marker for molecular changes in hepatocyte TJs, we investigated the effects of CBDL on ZO-1 alpha + immunofluorescence (IF) localization and on ZO-1 alpha + mRNA and protein expression over 2 wk of CBDL. ZO-1 alpha + IF staining was altered after 2 days of CBDL and appeared to accumulate in pericanalicular regions after 7 and 9 days. Quantitative immunoblotting and ribonuclease protection revealed a marked increase in hepatic ZO-1 alpha + protein expression and ZO-1 alpha + mRNA levels, respectively. In contrast to changes in ZO-1 alpha + IF, which occurred throughout the lobule, and changes in mRNA and protein expression, which were maximal after 9 days of ligation, the maximal hepatocyte proliferation occurred within 2 days after CBDL and was confined to periportal regions. CBDL results in altered hepatic localization and increased expression of the TJ protein ZO-1 alpha + and appears to represent a specific response by hepatocytes to pathological junction injury independent of cell proliferation.

Download Full-text

Altered expression and function of hepatocyte gap junctions after common bile duct ligation in the rat

AJP Cell Physiology ◽

10.1152/ajpcell.1995.268.5.c1186 ◽

1995 ◽

Vol 268 (5) ◽

pp. C1186-C1194 ◽

Cited By ~ 45

Author(s):

M. B. Fallon ◽

M. H. Nathanson ◽

A. Mennone ◽

J. C. Saez ◽

A. D. Burgstahler ◽

...

Keyword(s):

Gap Junction ◽

Bile Duct Ligation ◽

Connexin 26 ◽

Mrna Levels ◽

Connexin 32 ◽

Common Bile Duct Ligation ◽

Rat Hepatocyte ◽

Protein Levels ◽

Gap Junction Communication ◽

Duct Ligation

Gap junction channels allow intercellular exchange of ions and small molecules between adjacent cells. Such communication coordinates cellular and organ function in tissues, although it is unclear if altered gap junction expression and communication contribute to organ dysfunction in pathological states. We examined the immunofluorescent (IF) localization and mRNA and protein levels of the two hepatocyte gap junction proteins connexin 32 and connexin 26, after hepatic injury induced by common bile duct ligation (CBDL) in the rat. Intercellular communication was measured by comparing gap junction-mediated coordination of hormone-induced Ca2+ signals in isolated rat hepatocyte couplets from control and CBDL animals. Connexin 32 plasma membrane IF, protein, and mRNA levels decreased markedly early after CBDL and remained low at 14 days. Connexin 26 plasma membrane IF and protein levels also decreased markedly after CBDL, but mRNA levels rose, and a partial return in membrane IF and protein levels was noted at 9 and 14 days. Coordination of vasopressin-induced Ca2+ signals between cells in isolated rat hepatocyte couplets 1 day after CBDL was significantly impaired compared with controls. These results demonstrate that hepatocyte gap junction communication is impaired early after CBDL because of decreased connexin protein levels. Disruption of gap junctions after CBDL may contribute to loss of hepatic functions that depend on gap junction communication.

Download Full-text