Effect of miR-126-5p Overexpression Activating PI3K/Akt Signaling Pathway on Myocardial Ischemia Reperfusion Injury in Rats
Objective To explored the effect of miR-126-5p overexpression on myocardial ischemia reperfusion inju-ry in kats.Methods Experimental scheme 1:A total of 48 SPF-grade male SD rats were randomly divided into sham op-eration group,MIRI group(MIRI model modeling),MIRI+agomiR-NC group(MIRI model modeling+agomiR-NC in-tervention),MIRI+agomiR-126-5p group(MIRI model modeling+miR-126-5p agomiR intervention),with 12 rats in each group.Experimental scheme 2:Another 48 male SD rats were randomly divided into sham operation group,MIRI group(MIRI model modeling),MIRI+LY294002 group[MIRI model modeling+phosphatidylinositol-3-kinase(PI3K)inhibitor LY294002 intervention]and MIRI+LY294002+agomiR-126-5p group(MIRI model modeling+PI3K inhibitor LY294002+miR-126-5p agomiR intervention).The mRNA level of miR-126-5p of rats was detected by reverse transcription polymerase chain reaction(RT-PCR);the serum levels of creatine kinase isoenzyme MB(CK-MB),myohemoglobin(Mb),cardiac troponin I(cTnI),interleukin 6(IL-6),IL-1β and tumor recrosis factor alpha(TNF-α)of rats were detected by enzyme-linked im-munosorbent assay(ELISA);the degree of pathological damage in myocardial tissue of rats was detected by hematoxylin-eosin(HE)staining;the myocardial cell apoptosis and the associated apoptotic protein Bcl-2-associated X(Bax)/B-cell lymphomat 2(Bcl-2)and cleaved Caspase-3/Caspase-3 ratio were measured by terminal deoxynucleotidyl transferase TdT-mediated biotin dUTP nick end-labeling(TUNEL);the contents of markers of oxidative stress superoxide dismutase(SOD)and malondialdehyde(MDA)in rats were measured by reagent kits;Western blot was used to detect the expres-sion level ratio of phosphorylated-PI3K(p-PI3K)/PI3K and phosphorylated protein kinase B(p-Akt)/Akt.Results Compared with MIRI group,the mRNA expression of miR-126-5p in MIRI+agomiR-126-5p group was increased,the levels of CK-MB,Mb and cTnI were decreased,the degree of pathological injury was obviously improved,the apoptosis rate was decreased,and the ratio of Bax/Bcl-2 and cleaved Caspase-3/Caspase-3 were decreased,the levels of TNF-α,IL-1β and IL-6 were decreased,the SOD activity was increased and the MDA content was decreased,while the ratio of p-PI3K/PI3K and p-Akt/Akt were increased(all P＜0.01).In addition,the miR-126-5p overexpression could partially re-verse the effect of PI3K inhibitor LY294002 on myocardial pathologic damage,inflammatory response,oxidative stress and pathway related proteins expression in MIRI rats.Conclusion The overexpression of miR-126-5p has a protective effect against myocardial injury in MIRI rats.
Myocardial ischemia reperfusion injurymiR-126-5pInflammatory cytokinesOxidative stressPhosphatidylinositol-3-kinase/protein kinase B
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