Activation of the Nuclear Receptor Fxr Improves Intestinal Cell Tolerance to Ischemia-Reperfusion Injury

Shock. 2018 Sep;50(3):316-323. doi: 10.1097/SHK.0000000000001019.

Abstract

The farnesoid X receptor (FXR) plays an important role in bile acid metabolism, intestinal homeostasis, and intestinal ischemia-reperfusion (I/R) injury. We aimed to clarify the potential effects of FXR on intestinal epithelial cell tolerance to intestinal I/R injury and reveal the underlying mechanisms. An intestinal I/R injury model was established by the occlusion of the superior mesenteric artery for ischemia for 1 h, followed by reperfusion for 4 h in C57BL/6 (wild type [WT]) and FXR mice. The small intestine injury was assessed by histological analysis. Diamine oxidase and TNF-α levels in the serum were measured. Expressions of Bcl-2, Bax, caspase-3, and cystathionine-γ-lyase (CSE) were determined by immunohostochemical staining. Oxygen-glucose deprivation/reperfusion (OGD/R) was used to make injury in cultured Caco-2 cells pretreated with FXR agonist (INT-747) or DL-propargylglycine (PAG) for 24 h. Cell viability and the expressions of NF-κB, TNF-α, and IL-6 were assessed. Compared with WT I/R mice, FXR knockout mice exacerbated intestinal I/R injury, intestinal epithelial apoptosis, and inflammatory response. The I/R injury in WT mice was alleviated with INT-747 pretreatment. CSE expression increased after intestinal I/R injury in WT but not in FXR mice. INT-747 enhanced Caco-2 cell viability and inhibited inflammatory response by blocking the NF-κB pathway after OGD/R injury, which was diminished by a CSE-specific inhibitor (PAG). Thus, we demonstrated that FXR activation enhances intestinal epithelial cell tolerance to I/R by suppressing the inflammatory response and NF-κB pathway via CSE mediation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caco-2 Cells
  • Chenodeoxycholic Acid / analogs & derivatives
  • Chenodeoxycholic Acid / pharmacology
  • Humans
  • Intestinal Diseases / genetics
  • Intestinal Diseases / metabolism*
  • Intestinal Diseases / pathology
  • Intestine, Small / metabolism*
  • Intestine, Small / pathology
  • Male
  • Mice
  • Mice, Knockout
  • NF-kappa B / genetics
  • NF-kappa B / metabolism
  • Receptors, Cytoplasmic and Nuclear / agonists
  • Receptors, Cytoplasmic and Nuclear / genetics
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Reperfusion Injury / genetics
  • Reperfusion Injury / metabolism*
  • Reperfusion Injury / pathology
  • Signal Transduction*

Substances

  • NF-kappa B
  • Receptors, Cytoplasmic and Nuclear
  • obeticholic acid
  • farnesoid X-activated receptor
  • Chenodeoxycholic Acid