miR-146a-5p/TXNIP axis attenuates intestinal ischemia-reperfusion injury by inhibiting autophagy via the PRKAA/mTOR signaling pathway

• Published in: Biochemical pharmacology 2022-03, Vol.197, p.114839-114839, Article 114839
• Main Authors: Zhenzhen, Liu, Wenting, Leng, Jianmin, Zhang, Guangru, Zhang, Disheng, Liu, Zhiyu, Zhao, Feng, Chen, Yajing, Shi, Yingxiang, Hao, Jipeng, Lv, Zhanhai, Wan, Yan, Zhang, Xin, Liu, Yongqiang, Liu, Yufang, Leng
• Format: Article
• Language: English
• Subjects: AMP-Activated Protein Kinases - metabolism; Animals; Autophagy; Autophagy - physiology; Caco-2 Cells; Carrier Proteins - biosynthesis; Humans; Intestinal ischemia-reperfusion; Intestines - blood supply; Intestines - metabolism; Intestines - pathology; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; MicroRNAs - biosynthesis; miR-146a-5p; mTOR; PRKAA; Reperfusion Injury - metabolism; Reperfusion Injury - pathology; Reperfusion Injury - prevention & control; Signal Transduction - physiology; Thioredoxins - biosynthesis; TOR Serine-Threonine Kinases - metabolism; TXNIP
• ISSN: 0006-2952; 1873-2968
• DOI: 10.1016/j.bcp.2021.114839

[Display omitted] Autophagy is being increasingly recognized as an important regulator of intestinal ischemia-reperfusion(I/R)injury, but its exact role is still debated. Emerging evidence suggests that miR-146a-5p is involved in the initiation and development of I/R injury, but its role in intestinal I/R injury remains unclear. The present study generated an intestinal I/R mouse model and an oxygen glucose deprivation/reoxygenation (OGD/R) Caco-2 cell model and found that autophagy was increased and contributed to the intestinal injury and cell death induced by I/R and OGD/R. In addition, in both I/R and OGD/R models, the miR-146a-5p expression level was decreased and accompanied by an increase in TXNIP expression. By transfecting cells with an miR-146a-5p inhibitor or mimic, we observed that miR-146a-5p inhibits autophagy during OGD/R by targeting TXNIP; this was confirmed by the dual luciferase reporter gene assay. Additionally, through overexpression and knockdown cell lines, we established that TXNIP regulates autophagy during intestinal I/R via the PRKAA/mTOR pathway. The interaction between TXNIP and p-PRKAA was verified by immunofluorescence co-localization and immunoprecipitation assays. Moreover, we confirmed that TXNIP is indispensable for miR-146a-5p-mediated cell protection. Finally, we observed that miR-146a-5p overexpression inhibits autophagy and attenuates intestinal I/R injury via the PRKAA/mTOR pathway by targeting TXNIP in vivo. In conclusion, this study highlights the role of miR-146a-5p in regulating autophagy by targeting TXNIP, suggesting that miR-146a-5p may be a novel drug target for intestinal I/R therapy.