MicroRNA-29b-3p reduces intestinal ischaemia/reperfusion injury via targeting of TNF receptor-associated factor 3.

The microRNA miR-29b-3p shows important roles in regulating apoptosis and inflammation. However, its effects on intestinal ischaemia/reperfusion (II/R) injury have not been reported. Here we have investigated the functions of miR-29b-3p on II/R injury on order to find drug targets to treat the injury. Two models - in vitro hypoxia/reoxygenation (H/R) of IEC-6 cells; in vivo, II/R injury in C57BL/6 mice were used. Western blotting and dual-luciferase reporter assays were used and mimic and siRNA transfection tests were applied to assess the effects of miR-29b-3p on II/R injury via targeting TNF receptor-associated factor 3 (TRAF3). The H/R procedure decreased cell viability and promoted inflammation and apoptosis in IEC-6 cells, and the II/R procedure also promoted intestinal inflammation and apoptosis in mice. Expression levels of miR-29b-3p were decreased in H/R-induced cells and II/R-induced intestinal tissues of mice compared with control group or sham group, which directly targeted TRAF3. Decreased miR-29b-3p level markedly increased TRAF3 expression via activating TGF-α-activated kinase 1 phosphorylation, increasing NF-κB (p65) levels to promote inflammation, up-regulating Bcl2-associated X expression, and down-regulating Bcl-2 expression to trigger apoptosis. In addition, the miR-29b-3p mimetic and TRAF3 siRNA in IEC-6 cells markedly suppressed apoptosis and inflammation to alleviate II/R injury via inhibiting TRAF3 signallimg. The miR-29b-3p played a critical role in II/R injury, via targeting TRAF3, which should be considered as a significant drug target to treat the disease.

Dai Y ，Mao Z ，Han X ，Xu Y ，Xu L ，Yin L ，Qi Y ，Peng J ... -  《-》

MicroRNA-29b-3p promotes intestinal permeability in IBS-D via targeting TRAF3 to regulate the NF-κB-MLCK signaling pathway.

Irritable bowel syndrome with predominant diarrhea (IBS-D) is characterized by increased intestinal permeability. Previous studies have shown that the microRNA-29 gene is involved in the regulation of intestinal permeability in patients with IBS-D. NF-κB was proved to play a key role in inflammatory response of intestine and resultant disruption of tight junction integrity, whose activity could be inhibited by TNF Receptor-Associated Factor 3 (TRAF3). However, the exact mechanism that induces increased intestinal permeability in IBS-D patients has not been clarified. In this study, we found that microRNA-29b‑3p (miR-29b-3p) was significantly upregulated, while TRAF3 was decreased and the NF-κB-MLCK pathway was activated within the colonic tissue of IBS-D patients. Subsequently, we confirmed the targeting relationship between miR-29b-3p and TRAF3 through a double-luciferase reporter assay. Lentivirus transfection of NCM460 cells with miR-29b-3p-overexpressing and -silencing vectors demonstrated that the expression of TRAF3 was negatively correlated with the level of miR-29b-3p. The NF-κB/MLCK pathway was activated in the miR-29b-3p-overexpressing group and inhibited to some extent in the miR-29b-3p-silencing group. Results in WT and miR-29 knockout mice showed that miR-29b-3p levels were increased, TRAF3 levels were decreased, and the NF-κB/MLCK signaling was activated in the WT IBS-D group as compared with the WT control group. The protein levels of TRAF3 and TJs in the miR-29b-/- IBS-D group were partially recovered and NF-κB/MLCK pathway indicators were, to a certain extent, decreased as compared with the WT IBS-D group. These results suggested that miR-29b-3p deletion enhances the TRAF3 level in IBS-D mice and alleviates the high intestinal permeability. In brief, through the analysis of intestinal tissue samples from IBS-D patients and miR-29b-/- IBS-D mice, we showed that miR-29b-3p is involved in the pathogenesis of intestinal hyperpermeability in IBS-D via targeting TRAF3 to regulate the NF-κB-MLCK signaling pathway.

Wang Y ，Ke W ，Gan J ，Zhu H ，Xie X ，He G ，Liu S ，Huang Y ，Tang H ... -  《PLoS One》

MiR-92b-3p regulates oxygen and glucose deprivation-reperfusion-mediated apoptosis and inflammation by targeting TRAF3 in PC12 cells.

What is the central question of this study? MiR-92b-3p was found to be reduced in a rat model of middle cerebral artery occlusion: what are the functions of miR-92b-3p in oxygen and glucose deprivation-reperfusion (OGD/R)? What is the main finding and its importance? MiR-92b-3p abated apoptosis, mitochondrial dysfunction and inflammation caused by OGD/R via targeting TRAF3, suggesting that miR-92b-3p may serve as a potential therapeutic target in ischaemic stroke treatment. Stroke is the most common cause of human neurological disability. MiR-92b-3p has been shown to be decreased in a rat model of middle cerebral artery occlusion, but its effects in cerebral ischaemic insult are unknown. In this study, PC12 cells were exposed to oxygen and glucose deprivation-reperfusion (OGD/R) to establish cerebral ischaemic injury in vitro. Quantitative real time-PCR analysis demonstrated that OGD/R exposure led to down-regulation of miR-92b-3p and increased mRNA and protein levels of tumour necrosis factor receptor-associated factor 3 (TRAF3). Gain of miR-92b-3p expression facilitated cell survival; attenuated lactate dehydrogenase leakage, cell apoptosis, caspase 3 activity and cleaved-caspase 3 (c-caspase 3) expression; and decreased the Bax/Bcl-2 ratio. Furthermore, miR-92b-3p repressed mitochondrial membrane potential depolarization, reactive oxygen species production, cytochrome c protein expression, inflammatory cytokine production and the reduction of ATP content. MiR-92b-3p directly targeted the 3'-untranslated region of TRAF3 and decreased TRAF3 expression. Reinforced expression of TRAF3 partly abrogated the biological activity of miR-92b-3p during OGD/R. Hence, miR-92b-3p abated apoptosis, mitochondrial dysfunction and inflammatory responses induced by OGD/R by targeting TRAF3.

Liu E ，Sun H ，Wu J ，Kuang Y ... -  《-》

miR-29b-3p promotes progression of MDA-MB-231 triple-negative breast cancer cells through downregulating TRAF3.

Zhang B ，Shetti D ，Fan C ，Wei K ... -  《-》

MicroRNA-142-3p attenuates hepatic ischemia/reperfusion injury via targeting of myristoylated alanine-rich C-kinase substrate.

MiR-142-3p as one key molecule in oncogenesis and inflammation plays crucial roles in hepatic fibrosis, hepatocellular carcinoma and other liver disease. However, there have no literatures to report its effects on hepatic ischemia-reperfusion (HI/R) injury. In the present work, hypoxia reoxygenation (H/R) models on AML12 and HepG2 cells, and ischemia/reperfusion model in mice were established. The methods of real-time PCR, dual luciferase reporter, mimic, inhibitor, agomir, antagomir and siRNA transfection assays were used. The expression levels of miR-142-3p were decreased in model groups in vitro and in vivo compared with control group or Sham group, which directly targeted MARCKS to regulate its expression. Then, MARCKS activated p38/JNK signal, up-regulated NF-κB expression to accelerate inflammation, and inhibited PI3K/AKT signal to promote apoptosis. Moreover, miR-142-3p mimic in vitro and agomir in vivo lowered the expression levels of MARCKS, thereby alleviating apoptosis and inflammation to relieve HI/R injury. Furthermore, miR-142- 3p inhibitor in vitro and antagomir in vivo up-regulated the expression levels of MARCKS to aggravate HI/R damage via promoting inflammation and apoptosis. Consistently, MARCKS siRNA markedly inhibited HI/R injury by restraining apoptosis and inflamm- ation in mice. MiR-142-3p played a considerable part in adjusting HI/R injury by targeting MARCKS, and miR-142-3p/MARCKS should be a new therapeutic target for HI/R injury.

Li Y ，Gao M ，Xu LN ，Yin LH ，Qi Y ，Peng JY ... -  《-》