Sustained Isoprostane E2 Elevation, Inflammation and Fibrosis after Acute Ischaemia-Reperfusion Injury Are Reduced by Pregnane X Receptor Activation

PLoS One. 2015 Aug 24;10(8):e0136173. doi: 10.1371/journal.pone.0136173. eCollection 2015.

Abstract

Liver grafts donated after cardiac death are increasingly used to expand the donor pool but are prone to ischaemic-type biliary lesions. The anti-inflammatory effects of the activated pregnane X receptor have previously been shown to be beneficial in a number of inflammatory liver conditions. However, its role in reducing peri-portal inflammation and fibrosis following ischaemia-reperfusion injury has not been investigated. Hepatic injury and its response to pregnane X receptor activation was examined after partial hepatic ischaemia-reperfusion injury induced by surgically clamping the left and middle lobar blood vessels in rats. Molecular and pathological changes in the liver were examined over the following 28 days. Ischaemia-reperfusion injury resulted in transient cholestasis associated with microvillar changes in biliary epithelial cell membranes and hepatocellular injury which resolved within days after reperfusion. However, in contrast to chemically-induced acute liver injuries, this was followed by sustained elevation in isoprostane E2, peri-portal inflammation and fibrosis that remained unresolved in the ischaemic reperfused lobe for at least 28 days after clamping. Administration of pregnenolone-16α-carbonitrile--a rodent-specific pregnane X receptor activator--resulted in significant reductions in cholestasis, hepatic injury, ischaemic lobe isoprostane E2 levels, peri-portal inflammation and fibrosis. Hepatic ischaemia-reperfusion injury therefore results in inflammatory and fibrotic changes that persist well beyond the initial ischaemic insult. Drug-mediated activation of the pregnane X receptor reduced these adverse changes in rats, suggesting that the pregnane X receptor is a viable drug target to reduce ischaemic-type biliary lesions in recipients of liver transplants donated after cardiac death.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bile Ducts / drug effects
  • Bile Ducts / metabolism
  • Bile Ducts / pathology
  • Blood Vessels / drug effects
  • Blood Vessels / metabolism
  • Blood Vessels / pathology
  • Cholestasis / chemically induced
  • Cholestasis / physiopathology*
  • Constriction
  • Humans
  • Inflammation / drug therapy*
  • Inflammation / metabolism
  • Inflammation / physiopathology
  • Isoprostanes / biosynthesis*
  • Isoprostanes / metabolism
  • Liver / drug effects
  • Liver / injuries
  • Liver / metabolism
  • Liver / physiopathology
  • Liver Cirrhosis / drug therapy*
  • Liver Cirrhosis / metabolism
  • Liver Cirrhosis / pathology
  • Liver Transplantation
  • Pregnane X Receptor
  • Pregnenolone Carbonitrile / administration & dosage
  • Rats
  • Receptors, Steroid / biosynthesis*
  • Receptors, Steroid / metabolism
  • Reperfusion Injury / chemically induced
  • Reperfusion Injury / metabolism
  • Reperfusion Injury / physiopathology

Substances

  • Isoprostanes
  • Pregnane X Receptor
  • Receptors, Steroid
  • Pregnenolone Carbonitrile