Effect of miR-223-3p regulates FOXO3a-mediated autophagy in hepatic ischemia-reperfusion injury / 中华器官移植杂志

ABSTRACT

Objective:To explore the effect of miR-223-3p regulating FOXO3a-mediated autophagy in hepatic injury-reperfusion injury (LIRI).Methods:The model of hepatic ischemia-reperfusion injury (IR) was established in C57BL6 mice. According to different reperfusion timepoints, mice were randomly divided into 2 h, 6 h, 12 h and 24 h group. For sham group, there was no intraoperative clamping of hepatic pedicle. Murine hepatic AML12 cells were treated with miR-223-3p mimics, miR-223-3p inhibitor and FOXO3a interfering RNA. A hypoxic 1 h reoxygenation 6 h model was established. And miRNA-NC, miR-223-3p mimics, miR-223-3p inhibitor and siRNA-NC and FOXO3a siRNA groups were assigned. Hepatic injury and apoptosis were detected by hematoxylin eosin or TdT-mediated nick end labeling (HE/TUNEL) at different timepoints. The changes of proliferating cell nuclear antigen (PCNA) and Caspase-3 in hepatocytes were detected by immunohistochemistry. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were employed for detecting the expressions of miR-223-3p, FOXO3a, LC3, p62 and Caspase-3 in hepatocytes.Results:The results of HE/TUNEL indicated that reperfusion injury and apoptosis of hepatic tissue were most severe in 12 h group. In hepatic ischemia-reperfusion model, RT-PCR results showed that the expressions of miR-223-3p and FOXO3a were higher in IR group than those in sham group (1.00±0), the expression level of miR-223-3p mRNA peaked at 12 h (9.13±2.12) after reperfusion and FOXO3a was the highest at 6 h (5.23±0.90, P<0.05). Western blot showed that the expression of FOXO3a peaked at 6 h post-reperfusion and the expressions of LC3 and caspase-3 were the highest at 12 h. ( P<0.05). In the model of cell hypoxia and reoxygenation, RT-PCR indicated that the expression of FOXO3a mRNA decreased in miR-223-3p mimics group (0.45±0.21) as compared with miRNA-NC group (1.00±0). In contrast, miR-223-3p inhibitor group increased (2.73±0.53, P<0.05). Western blot indicated that FOXO3a protein expression was highest in miR-223-3p inhibitor and miR-223-3p mimics groups whereas LC3 and Caspase-3 were the highest in miR-223-3p mimics group ( P<0.05). The expression of FOXO3a was higher in siRNA-NC group than that in FOXO3a siRNA group while the expressions of Caspase-3 and LC3 were the higher in FOXO3a siRNA group. Conclusions:FOXO3a has protective effect on hepatic ischemia-reperfusion injury. It may be related to its inhibition of autophagy and apoptosis and miR-223-3p promotes injury through a down-regulation of FOXO3a-mediated autophagy. It suggests that miR-223-3p and FOXO3a are negatively correlated and may be potential gene therapeutic targets for hepatic injury.