Published in:
01-01-2017 | Original Article
Ischemic Preconditioning-Induced SOCS-1 Protects Rat Intestinal Ischemia Reperfusion Injury via Degradation of TRAF6
Published in: Digestive Diseases and Sciences | Issue 1/2017
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Background
The inflammatory immune response plays an important role in mesenteric ischemia and ischemia–reperfusion injury. Toll-like receptor 4 (TLR4) is a critical receptor in transduction of the inflammatory response and plays an important role in intestinal homeostasis. Tumor necrosis factor receptor-associated factor 6 (TRAF6), known as a key adaptor protein downstream of TLR4, is involved in the inflammatory response by activating multiple apoptotic signaling pathways. However, mechanisms of the suppressor of cytokine signaling-1 (SOCS-1) in regulating cell inflammation and apoptosis are still obscure.
Objectives
To investigate the TLR4–TRAF6 signaling pathway in intestinal ischemia and reperfusion injury, as well as SOCS-1 expression after ischemic preconditioning in the rat intestine.
Methods
The small bowel ischemia, ischemia–reperfusion, and preconditioning models were induced using ligation of the superior mesenteric artery in male Sprague–Dawley rats; then, the mRNA and protein levels of TLR4, TRAF6, and SOCS-1 were analyzed using real-time PCR, Western blot, and immunohistochemistry, respectively.
Results
The expression of TLR4 and TRAF6 was gradually increased with increasing intestinal ischemia duration, but increased substantially after ischemia–reperfusion injury. After ischemic preconditioning, TLR4 and TRAF6 expressions decreased; however, expression of SOCS-1 and the TLR4–TRAF6 pathway inhibitor was increased.
Conclusion
These data show that ischemic preconditioning may induce the activation of SOCS-1 to inhibit the TLR4–TRAF6 signaling pathway, thereby playing a protective role in ischemia–reperfusion injury.