Related Experiment Video

Updated: Jun 4, 2026

Partial Bile Duct Ligation in the Mouse: A Controlled Model of Localized Obstructive Cholestasis
04:38

Partial Bile Duct Ligation in the Mouse: A Controlled Model of Localized Obstructive Cholestasis

Published on: March 28, 2018

Changes of organic anion transporter MRP4 and related nuclear receptors in human obstructive cholestasis

Jin Chai1, Donglin Luo, Xiaoping Wu

  • 1Institute of Gastroenterology, Southwest Hospital, Third Military Medical University, Chongqing, 400038, People's Republic of China. chaijinsw@yahoo.com

Journal of Gastrointestinal Surgery : Official Journal of the Society for Surgery of the Alimentary Tract
|March 2, 2011
PubMed
Abstract

Insights

Hepatic multidrug resistance-associated protein 4 (MRP4) is significantly elevated in human obstructive cholestasis. This increase may protect the liver by enhancing the elimination of toxic bile acids.

Area of Science:

  • Hepatology
  • Molecular Biology
  • Drug Metabolism

Background:

  • Hepatic multidrug resistance-associated protein 4 (MRP4) expression is low but increases in rodent cholestasis.
  • Nuclear receptors (NRs) regulate Mrp4 in cholestasis, but their role in human obstructive cholestasis is understudied.
  • Key NRs include constitutive androstane receptor (CAR), pregnane X receptor (PXR), and retinoic X receptor-α (RXRα).

Purpose of the Study:

  • To investigate the expression of MRP4 and NRs (CAR, PXR, RXRα) in human obstructive cholestasis.
  • To determine the relationship between MRP4 and NRs in the context of human obstructive cholestasis.

Main Methods:

  • Collection of liver samples from patients with and without obstructive cholestasis.
  • Semi-quantitative RT-PCR, Western blot, and immunostaining assays were used to analyze gene and protein expression.
  • Correlation analysis was performed to assess relationships between variables.

Main Results:

  • MRP4 mRNA and protein levels were significantly increased in obstructive cholestasis.
  • Serum total bile acids (TBA) positively correlated with MRP4 protein levels.
  • PXR and RXRα mRNA/protein levels were elevated, while CAR protein was markedly induced.
  • A positive correlation was observed between MRP4 mRNA and CAR protein, suggesting CAR's role in MRP4 gene transcription.

Conclusions:

  • Hepatic MRP4 is dramatically induced in human obstructive cholestasis.
  • This induction may mitigate liver injury by increasing the efflux of toxic bile acids.
  • CAR activation appears to play a role in the transcriptional regulation of MRP4.

Related Concept Videos

Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters01:16

Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters

The pharmacogenetics of drug transporters is increasingly recognized as a critical factor influencing interindividual variability in drug absorption, distribution, and elimination. These membrane-bound proteins regulate drugs' movement across cellular barriers by actively pumping them out (efflux) or facilitating their uptake (influx). Among the major transporter families, ATP-binding cassette (ABC) and solute carrier (SLC) transporters play particularly prominent roles. Genetic polymorphisms...
Physiological Pharmacokinetic Models: Incorporating Hepatic Transporter-Mediated Clearance01:07

Physiological Pharmacokinetic Models: Incorporating Hepatic Transporter-Mediated Clearance

Drug transporters are critical in drug absorption, distribution, and excretion processes. They should be included in physiological-based pharmacokinetic (PBPK) models, which help predict human drug disposition. However, predicting this is challenging during drug development, especially when liver transport is involved. However, with a realistic representation of body transport processes, an accurate model may be possible.
A recent model describes pravastatin's hepatobiliary excretion, mediated...
Carrier-Mediated Transport01:06

Carrier-Mediated Transport

Carrier-mediated transport is a pivotal process in drug absorption, particularly for lipid-insoluble drugs, and encompasses facilitated diffusion and active transport. Facilitated diffusion allows drugs to move along their concentration gradient without energy expenditure, while active transport utilizes ATP to drive drug movement against this gradient.
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
Hepatic Drug Clearance: Role of Transporters01:14

Hepatic Drug Clearance: Role of Transporters

In the liver and bile canaliculi, influx and efflux transporters modification can influence intrinsic clearance. Transporters play a significant role in moving drugs within liver cells. Elaborate models, such as the Biopharmaceutical Classification System (BCS), are essential to relate transporters to drug disposition. This system categorizes drugs into four classes based on solubility and permeability, providing insights into elimination routes and the effects of transporters following oral...
Pharmacokinetics in Obese Patients: Drug Metabolism and Excretion01:20

Pharmacokinetics in Obese Patients: Drug Metabolism and Excretion

Drug metabolism, a critical process in the liver, involves two primary phases: Phase I reactions and Phase II conjugation. Obesity introduces significant alterations in this metabolic process, primarily due to fatty infiltration of the liver, leading to conditions such as nonalcoholic fatty liver disease (NAFLD). This condition can modify the activities of both Phase I and II enzymes, impacting how drugs are metabolized in obese patients.Phase I metabolism sees variable effects across...
Cholecystitis01:20

Cholecystitis

Cholecystitis is inflammation of the gallbladder, most commonly caused by obstruction of the cystic duct. This blockage prevents bile from draining, leading to gallbladder distension, inflammation, and potentially serious complications. This condition may present acutely or chronically and can happen with or without gallstones.EtiologyAbout 95% of cholecystitis cases are calculous, caused by gallstones blocking the cystic duct, leading to bile accumulation and inflammation of the gallbladder...