The role of macrophages in the development of biliary injury in a lipopolysaccharide-aggravated hepatic ischaemia-reperfusion model

J. Reiling*, K. R. Bridle, F. G. Schaap, L. Jaskowski, N. Santrampurwala, L. J. Britton, C. M. Campbell, P. L. M. Jansen, S. W. M. Olde Damink, D. H. G. Crawford, C. H. C. Dejong, J. Fawcett

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

4 Citations (Web of Science)

Abstract

Introduction: Endotoxins, in the form of lipopolysaccharides (LPS), are potent inducers of biliary injury. However the mechanism by which injury develops remains unclear. We hypothesized that hepatic macrophages are pivotal in the development of endotoxin-induced biliary injury and that no injury would occur in their absence.

Material and methods: Clodronate liposomes were used to deplete macrophages from the liver. Forty-eight rats were equally divided across six study groups: sham operation (sham), liposome treatment and sham operation (liposomes + sham), 1 mg/kg LPS i.p. (LPS), liposome treatment and LPS administration (liposomes + LPS), hepatic ischaemia-reperfusion injury with LPS administration (IRI + LPS) and liposome treatment followed by IRI + LPS (liposomes + IRI + LPS). Following 6 h of reperfusion, blood, bile, and liver tissue was collected for further analysis. Small bile duct injury was assessed, serum liver tests were performed and bile composition was evaluated. The permeability of the blood-biliary barrier (BBB) was assessed using intravenously administered horseradish peroxidase (HRP).

Results: The presence of hepatic macrophages was reduced by 90% in LPS and IRI + LPS groups pre-treated with clodronate liposomes (P <0.001). Severe small bile duct injury was not affected by macrophage depletion, and persisted in the liposomes + IRI + LPS group (50% of animals) and liposomes + LPS group (75% of animals). Likewise, BBB impairment persisted following macrophage depletion. LPS-induced elevation of the chemokine Mcp-1 in bile was not affected by macrophage depletion.

Conclusions: Depletion of hepatic macrophages did not prevent development of biliary injury following LPS of LPS-enhanced IRI. Cholangiocyte activation rather than macrophage activation may underlie this injury. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by Jesus Banales, Marcc Marzioni, Nicholas LaRusso and Peter Jansen.

Original languageEnglish
Pages (from-to)1284-1292
Number of pages9
JournalBiochimica et Biophysica Acta-Molecular Basis of Disease
Volume1864
Issue number4
DOIs
Publication statusPublished - Apr 2018

Keywords

  • Macrophages
  • Cholangiocytes
  • Endotoxaemia
  • Donation after circulatory death
  • Liver transplantation
  • TOLL-LIKE RECEPTORS
  • LIVER-TRANSPLANTATION
  • EPITHELIAL-CELLS
  • RAT-LIVER
  • SCLEROSING CHOLANGITIS
  • ENDOTOXIN LEVELS
  • BARRIER FUNCTION
  • TIGHT JUNCTIONS
  • BILE-DUCTS
  • ACTIVATION

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