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Updated: Aug 9, 2026
Partial Bile Duct Ligation in the Mouse: A Controlled Model of Localized Obstructive Cholestasis
Published on: March 28, 2018
Mrp4-/- mice have an impaired cytoprotective response in obstructive cholestasis
Albert Mennone1, Carol J Soroka, Shi-Ying Cai
1Liver Center and Department of Medicine, Yale University School of Medicine, New Haven, CT, USA.
Abstract:
Mrp4 is a member of the multidrug resistance-associated gene family that is expressed on the basolateral membrane of hepatocytes and undergoes adaptive upregulation in response to cholestatic injury or bile acid feeding. However, the relative importance of Mrp4 in a protective adaptive response to cholestatic injury is not known. To address this issue, common bile duct ligation (CBDL) was performed in wild-type and Mrp4-/- mice and animals followed for 7 days. Histological analysis and serum aminotransferase levels revealed more severe liver injury in the absence of Mrp4 expression. Western analyses revealed that Mrp4, but not Mrp3, was significantly increased after CBDL in wild-type mice. Serum bile acid levels were significantly lower in Mrp4-/- mice than in wild-type CBDL mice, whereas serum bilirubin levels were the same, suggesting that Mrp4 was required to effectively extrude bile acids from the cholestatic liver. Mrp3 and Ostalpha-Ostbeta were upregulated in Mrp4-/- mice but were unable to compensate for the loss of Mrp4. High-performance liquid chromatography analysis on liver extracts revealed that taurine tetrahydroxy bile acid/beta-muricholic acid ratios were increased twofold in Mrp4-/- mice. In conclusion, hepatic Mrp4 plays a unique and essential protective role in the adaptive response to obstructive cholestatic liver injury.
Insights
Hepatobiliary transporter Mrp4 (multidrug resistance-associated protein 4) is crucial for protecting the liver from bile acid overload during cholestatic injury. Its absence worsens liver damage, highlighting its essential role in bile acid extrusion.
Area of Science:
- Hepatology
- Molecular Biology
- Drug Transport
Background:
- Multidrug resistance-associated protein 4 (Mrp4) is expressed in liver cells and upregulated during cholestasis.
- The protective role of Mrp4 in cholestatic liver injury remains unclear.
Purpose of the Study:
- To investigate the functional significance of Mrp4 in the adaptive response to obstructive cholestatic liver injury.
Main Methods:
- Common bile duct ligation (CBDL) was performed in wild-type and Mrp4 knockout mice.
- Liver injury was assessed via histology and serum aminotransferase levels.
- Bile acid and bilirubin levels were measured; transporter expression was analyzed by Western blot.
Main Results:
- Mice lacking Mrp4 exhibited more severe liver injury and higher serum aminotransferase levels after CBDL.
- Mrp4 knockout mice had lower serum bile acid levels, indicating impaired bile acid extrusion.
- Upregulation of Mrp3 and Ostalpha-Ostbeta in Mrp4-/- mice could not compensate for Mrp4 deficiency.
Conclusions:
- Hepatic Mrp4 is essential for the adaptive response to obstructive cholestatic liver injury.
- Mrp4 plays a unique role in extruding bile acids from the cholestatic liver, preventing further damage.
