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Updated: Feb 25, 2026
Murine Model of Intestinal Ischemia-reperfusion Injury
Published on: May 11, 2016
MiR-146a protects small intestine against ischemia/reperfusion injury by down-regulating TLR4/TRAF6/NF-κB pathway
Xuemei He1, Yingqiang Zheng2, Shengzhi Liu3
1Experimental Medicine Center, The Affiliated Hospital of Southwest Medical University, Luzhou, China.
Abstract:
Previous studies reported that miR-146a was involved in small intestine ischemia-reperfusion (I/R) injury, but the mechanism is largely vague. Here, we aimed to identify the change of miR-146a in patients with mesenteric ischemia and explore the potential regulatory mechanism of miR-146a in intestine epithelial cells survival under ischemia and I/R injury. The plasma of 20 patients with mesenteric ischemia and 25 controls was collected to examine the miR-146a expression by qPCR. Rat intestinal epithelial cells (IEC-6) and 24 male Sprague-Dawley rats were included to build ischemia and I/R model in vitro and in vivo. The qPCR results showed that miR-146a decreased both in the plasma of patients with mesenteric ischemia and in IEC-6 cells and rat small intestine tissues in ischemia and I/R model compared to controls. Both the in vitro and in vivo results showed that I/R resulted in more severe apoptotic injury than ischemia. Cleaved-caspase 3, TLR4, TRAF6, and nuclear NF-κB p65 were up-regulated accompanying reduced XIAP and SOCS3 expression in intestinal ischemia and I/R injury. After up-regulation of miR-146a in IEC-6 cells, increased cell survival and decreased cell apoptosis were observed, concomitant with decreased cleaved-caspase 3 and down-regulated TLR4/TRAF6/NF-κB pathway. What is more, this protective effect was blocked by TRAF6 overexpression and increased nuclear NF-κB p65 nuclear. Taken together, this study revealed that miR-146a expression was decreased in small intestine ischemia and I/R injury. And miR-146a improves intestine epithelial cells survival under ischemia and I/R injury through inhibition TLR4, TRAF6, and p-IκBα, subsequently leading to decreased NF-κB p65 nuclear translocation.
Insights
MicroRNA-146a (miR-146a) levels decrease in small intestine ischemia-reperfusion (I/R) injury. Upregulating miR-146a protects intestinal epithelial cells by inhibiting the TLR4/TRAF6/NF-κB pathway, improving survival.
Area of Science:
- Gastroenterology
- Molecular Biology
- Cell Biology
Background:
- Small intestine ischemia-reperfusion (I/R) injury is a critical condition with significant morbidity.
- The precise molecular mechanisms underlying I/R injury, particularly the role of microRNAs, remain incompletely understood.
- Previous research suggested a role for microRNA-146a (miR-146a) in I/R injury, but its functional mechanism was unclear.
Purpose of the Study:
- To investigate the expression levels of miR-146a in patients with mesenteric ischemia.
- To elucidate the regulatory role and mechanism of miR-146a in intestinal epithelial cell survival during ischemia and I/R injury.
- To explore the potential therapeutic implications of modulating miR-146a in I/R injury.
Main Methods:
- Quantitative real-time PCR (qPCR) was used to measure miR-146a expression in plasma from patients and in rat intestinal epithelial cells (IEC-6) and tissues.
- In vitro and in vivo models of intestinal ischemia and I/R were established using IEC-6 cells and Sprague-Dawley rats.
- Western blotting and immunofluorescence were employed to assess protein expression and cellular localization, including cleaved-caspase 3, TLR4, TRAF6, NF-κB p65, XIAP, and SOCS3.
Main Results:
- miR-146a expression was significantly decreased in the plasma of mesenteric ischemia patients and in intestinal tissues/cells subjected to ischemia and I/R.
- Ischemia-reperfusion induced more severe apoptotic injury than ischemia alone, characterized by increased cleaved-caspase 3, TLR4, TRAF6, and nuclear NF-κB p65, alongside decreased XIAP and SOCS3.
- Upregulation of miR-146a in IEC-6 cells enhanced cell survival, reduced apoptosis, and suppressed the TLR4/TRAF6/NF-κB pathway. This protective effect was abrogated by TRAF6 overexpression or increased NF-κB nuclear translocation.
Conclusions:
- miR-146a plays a crucial protective role in mitigating intestinal epithelial cell damage during ischemia and I/R injury.
- The protective mechanism involves the inhibition of the TLR4/TRAF6/NF-κB signaling pathway, leading to reduced apoptosis and enhanced cell survival.
- Restoring miR-146a levels represents a potential therapeutic strategy for managing small intestine ischemia-reperfusion injury.
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