Detection Of The Regulation Effect And Mechanism Of MicroRNA-21on Renal Ischemia Reperfusion Injury

Objective:Detective the regulation effect and mechanism of MicroRNA-21on renalischemia reperfusion injury, finding the microRNA target of preventing and treatingrenal ischemia-reperfusion injuryMethods:Nontrau-matic microvascular clamps were applied across both renal pedicles toconstruct male BALB/c mice model of renal ischemia-reperfusion injury. Accordingthe preliminary experiment results and the purpose of this experiment the mice weredivided into four groups: Pre-miR-21+IRI group blocking the renal vascular pedicle45min and24h reperfusion mir-21agomir was administered intraperitoneally (200ng/kg weight)24hours and6hours before induction of ischemia. PBS+IRI groupblocking the renal vascular pedicle45min and24h reperfusion. Pre-miR-21+shamegroup which is only opened the abdominal cavity without blocking vascular renalpedicle and mir-21agomir was administered intraperitoneally (200ng/kg weight)24hours and6hours before induction of ischemia. PBS+shame group which is onlyopen the abdominal cavity without blocking vascular renal pedicle and PBS wasadministered intraperitoneally24hours and6hours before induction of ischemia.Themice were all feeded24hours after the surgery. Blood was collected to detectserum uria nitrogen and creatinine to determine kidney function24hours after thesurgery. Then the mice were sacrificed eagerly,taking a surgical incision from theback of the model mouse to obtain bilateral kidneys, HE staining one kidney,opticalmicroscope will be used to observed kidney histopathological changes.The otherkidney will be used to detect the expression of microRNA-21,the mRNA of PDCD4and PTEN and the expression of pro-caspase-3,cleaved caspase-3.Results:（1）24hours after the surgery the survival rate of PBS+shame group,Pre-miR-21+shame group,PBS+IRI group,Pre-miR-21+IRI group were respective be100%,100%,75%and87%.Kidney histopathology score and serum uria nitrogen and creatinine in Pre-miR-21+IRI group significantly lower than the PBS+IRI group,however these two groups were both higher than PBS+shame group andPre-miR-21+shame group（P＜0.05）. Kidney histopathology score and serum urianitrogen and creatinine in PBS+shame group and Pre-miR-21+shamegroup have nosignificant difference(P＞0.05).（2）24hours after the surgery the expression of miR-21were significantdifference among the four groups, the low expression levels of the order werePre-miR-21+IRI group、Pre-miR-21+shame group、PBS+IRI group and PBS+shamegroup (P＜0.05). In Pre-miR-21+IRI group the expression of target gene PDCD4、PTEN were low than PBS+IRI group，Pre-miR-21+IRI group�'�PBS+shame group（P＜0.05），however the expression have no significant difference betweenPBS+shame group and Pre-miR-21+shame group (P＞0.05).(3) The expression of cleaved caspase-3in Pre-miR-21+IRI group wassignificantly lower than the PBS+IRI group（P＜0.05）.In PBS+IRI group theexpression of cleaved caspase-3was higher than PBS+shame group andPre-miR-21+shame group（P＜0.05）. Among the four groups the pro-caspase-3haveno significant differences（P＞0.05）.Conclusion:(1) Renal ischemia reperfusion mode of male BALB/c mice were Successfullyconstructed.(2) Mir-21can carry negative regulation of its target genes PDCD4and PTEN;(3) miRNA-21regulates its target gene PDCD4and PTEN affecting theactivation of apoptotic protein caspase-3, participating in renal ischemia-reperfusioninjury regulation, and play a protective role in renal ischemia reperfusion.