Elevated hepatic multidrug resistance-associated protein 3/ATP-binding cassette subfamily C 3 expression in human obstructive cholestasis is mediated through tumor necrosis factor alpha and c-Jun NH2-terminal kinase/stress-activated protein kinase-signaling pathway

Hepatology. 2012 May;55(5):1485-94. doi: 10.1002/hep.24801.


Multidrug resistance-associated protein 3 (MRP3, ABC subfamily C [ABCC]3) plays an important role in protecting hepatocytes and other tissues by excreting an array of toxic organic anion conjugates, including bile salts. MRP3/ABCC3 expression is increased in the liver of some cholestatic patients, but the molecular mechanism of this up-regulation remains elusive. In this report, we assessed liver MRP3/ABCC3 expression in patients (n = 22) with obstructive cholestasis caused by gallstone blockage of bile ducts and noncholestatic patient controls (n = 22). MRP3/ABCC3 messenger RNA (mRNA) and protein expression were significantly increased by 3.4- and 4.6-fold, respectively, in these cholestatic patients where elevated plasma tumor necrosis factor alpha (TNFα) (4.7-fold; P < 0.01) and hepatic specificity protein 1 transcription factor (SP1) and liver receptor homolog 1 expression (3.1- and 2.1-fold at mRNA level, 3.5- and 2.5-fold at protein level, respectively) were also observed. The induction of hepatic MRP3/ABCC3 mRNA expression is significantly positively correlated with the level of plasma TNFα in these patients. In HepG2 cells, TNFα treatment induced SP1 and MRP3/ABCC3 expression in a dose- and time-dependent manner, where increased phosphorylation of c-Jun NH2-terminal kinase/stress-activated protein kinase (JNK/SAPK) was also detected. These inductions were significantly reduced in the presence of the JNK inhibitor, SP600125. TNFα treatment enhanced HepG2 cell nuclear extract-binding activity to the MRP3/ABCC3 promoter, but was abolished by SP600125, as demonstrated by electrophoretic mobility shift assay (EMSA). An increase in nuclear protein-binding activity to the MRP3/ABCC3 promoter, consisting primarily of SP1, was also observed in liver samples from cholestatic patients, as assessed by supershift EMSA assays.

Conclusions: Our findings indicate that up-regulation of hepatic MRP3/ABCC3 expression in human obstructive cholestasis is likely triggered by TNFα, mediated by activation of JNK/SAPK and SP1.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Biopsy, Needle
  • Blotting, Western
  • Case-Control Studies
  • Cholestasis / genetics
  • Cholestasis / metabolism*
  • Cholestasis / pathology
  • Disease Progression
  • Female
  • Fluorescent Antibody Technique
  • Gene Expression Regulation
  • Humans
  • JNK Mitogen-Activated Protein Kinases / genetics
  • JNK Mitogen-Activated Protein Kinases / metabolism*
  • Male
  • Middle Aged
  • Multidrug Resistance-Associated Proteins / genetics
  • Multidrug Resistance-Associated Proteins / metabolism*
  • RNA, Messenger / metabolism
  • Real-Time Polymerase Chain Reaction / methods
  • Sensitivity and Specificity
  • Signal Transduction
  • Sp1 Transcription Factor / metabolism*
  • Tissue Culture Techniques
  • Tumor Cells, Cultured / drug effects
  • Tumor Necrosis Factor-alpha / blood
  • Tumor Necrosis Factor-alpha / metabolism*
  • Up-Regulation


  • Multidrug Resistance-Associated Proteins
  • RNA, Messenger
  • Sp1 Transcription Factor
  • Tumor Necrosis Factor-alpha
  • multidrug resistance-associated protein 3
  • JNK Mitogen-Activated Protein Kinases