Suppression of microRNA-27a protects against liver ischemia/reperfusion injury by targeting PPARγ and inhibiting endoplasmic reticulum stress
Suppression of microRNA-27a protects against liver ischemia/reperfusion injury by targeting PPARγ and inhibiting endoplasmic reticulum stress
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DOI：
10.3892/mmr.2019.10645
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发表时间：
2019-11-01
影响因子：
3.4
通讯作者：
Zhang, Xiaojin
中科院分区：
文献类型：
--
作者：
Chi, Xiaobin;Jiang, Yi;Zhang, Xiaojin
肝缺血再灌注损伤是肝移植临床上的重要问题。最近的研究表明，microRNA参与各种生物和病理过程，包括肝脏I/R损伤。本研究旨在探讨miR-27 a在肝脏I/R损伤中的作用及其可能机制。采用大鼠肝脏缺血60 min再灌注6 h的方法建立肝I/R模型。用miR-27 a模拟物或miR-27 a抑制剂转染细胞，以检查miR-27 a对肝脏I/R的影响。流式细胞术和TUNEL染色检测凋亡细胞。实时荧光定量PCR检测miR-27 a的表达。Western blot检测过氧化物酶体增殖物激活受体γ（PPAR γ）、胃泌素释放肽78（GRP 78）和C/EBP同源蛋白（CHOP）的表达。结果显示，在体内和体外I/R损伤过程中，miR-27 a均显著上调。此外，miR-27 a抑制剂减弱了缺氧/复氧（H/R）诱导的氧化应激、内质网应激（ERS）和AML 12细胞凋亡。相比之下，miR-27 a模拟物促进缺氧/复氧诱导的ERS和凋亡。此外，使用生物信息学分析和双荧光素酶报告基因测定，将PPAR γ鉴定为miR-27 a的靶基因。PPAR γ的敲除显着消除了miR-27 a抑制剂对ERS途径的抑制作用。此外，miR-27 a抑制剂减轻了大鼠肝脏I/R损伤，这一发现表现为ALT/AST降低、肝细胞凋亡、氧化应激和ERS途径抑制。综上所述，这些发现表明，抑制miR-27 a通过靶向PPAR γ和抑制ERS通路来保护肝脏免受I/R损伤。
Liver ischemia-reperfusion (I/R) injury is an important clinical issue related to liver transplantation. Recent studies suggest that microRNAs are implicated in various biological and pathological processes, including liver I/R injury. This study aimed to investigate the role and potential mechanism of miR-27a during liver I/R injury. A liver I/R model was induced via 60 min of ischemia and reperfusion for 6 h in rats. Cells were transfected with miR-27a mimics or the miR-27a inhibitor to examine the effect of miR-27a on liver I/R. Apoptotic cells were detected by flow cytometry and TUNEL staining. The expression of miR-27a was measured by real-time PCR. The expression of peroxisome proliferator-activated receptor gamma (PPAR gamma); gastrin-releasing peptide 78 (GRP78) and C/EBP homologous protein (CHOP) were detected by western blot analysis. The results showed that miR-27a was significantly upregulated during I/R injury in vivo and in vitro. In addition, miR-27a inhibitors attenuated hypoxia/reoxygenation (H/R)-induced oxidative stress, endoplasmic reticulum stress (ERS) and apoptosis in AML12 cells. By contrast, miR-27a mimics promoted hypoxia/reoxygenation-induced ERS, and apoptosis. Furthermore, PPAR gamma was identified as a target gene of miR-27a using bioinformatic analysis and a dual-luciferase reporter assay. Knockdown of PPAR gamma significantly abrogated the inhibitory effect of miR-27a inhibitors on the ERS pathway. Moreover, the miR-27a antagomir attenuated liver I/R injury in rats, a finding manifested by reduced ALT/AST, hepatocyte apoptosis, oxidative stress and inhibition of the ERS pathway. Taken together, these findings demonstrate that suppression of miR-27a protects against liver I/R injury by targeting PPAR gamma and by inhibiting the ERS pathway.