Roles Of MiRNA-21 On Inflammation Of Atherosclerosis

Objective: The present study aimed to investigate the roles of mi RNA(mi R)-21 on inflammation of atherosclerosis(AS).Methods: We enrolled 74 consecutive patients diagnosed acute ST elevation myocardial infarction(STEMI)in our department,and 50 non-coronary heart disease patients were enrolled randomly in control group.The patients who suffered from malignant tumor,severe insufficiency of function in liver and kidney or connective tissue disease were all excluded.simultaneously,the detailed clinical feature,laboratory index and the result of auxiliary examination were recorded at the time of peripheral blood sampling.The circulating mi R-21 levels were analyzed using quantitative RT-PCR(q RT-PCR).Plasma Interleukin-6(IL-6)was measured by the enzyme-linked immunosorbent assay(ELISA)according to the manufacturer's protocol.The relationship between acute STEMI and clinical indicators were analyzed by multiple Logistic regression.RAW 264.7 cells were transfected with the mi R-21 mimics,inhibitor,NC and programmed cell death 4 si RNA(si PDCD4)for 6h in mediation of Lipo3000,then added with ox-LDL to a final concentration of 50ug/ml and cultured for 48 h using those untransfected as blank control.The effect of mi R-21 and PDCD4 on bubbling of RAW 264.7 cells was analyzed by semi-quantitative oil red staining.The expression levels of mi R-21 in foam cells were detected using q RT-PCR.Western blot was used to measure the expression of PDCD4 protein,which is validated as a direct target gene of mi R-21.The expression of IL-6 and IL-10 in the supernatant of foam cells was assessed with ELISA.High fat feeding was given to Apo E-/-male mice(4-6 weeks)to establish AS animal model,and the mice were randomly divided into 3 groups: AS group,mi R-21 group and NC group.Every 3 days,mice in the mi R-21 group and NC group received tail vein injection of cholesterol conjugated mi R-21 agonist(agomi R-21)and NC,respectively.C57BL/6 mice fed with standard diet were arranged in the normal control group.q RT-PCR was performed to detect the expression levels of mi R-21 in atherosclerotic plaque and normal artery.Immunohistochemistry was used to measure the expression of PDCD4,IL-6 and IL-10.Results: 1.The levels of mi R-21 and IL-6 were markedly higher in acute STEMI patients than in the control group.Logistic regression analysis showed that age and male were independent risk factors for acute STEMI.2.The levels of mi R-21 and PDCD4 protein were much higher in foam cells than in RAW 264.7 cells.As compared with those in NC group,the bubbling levels in ox-LDL+mi R-21 mimics group and ox-LDL+si PDCD4 group decreased significantly,and IL-6 in the supernatant was increased,while IL-10 was decreased.3.The levels of mi R-21 and PDCD4 protein were much higher in atherosclerotic plaques than that in the normal arteries.Tail vein injection of agomi R-21 markedly inhibited the protein expression of PDCD4 and IL-6,and significantly decreased AS area.Conclusion: 1.The levels of mi R-21 and IL-6 were markedly higher in acute STEMI patients.age and male were independent risk factors for acute STEMI.2.The levels of mi R-21 and PDCD4 protein were much higher in foam cells and atherosclerotic plaques.The levels of IL-6 was significantly increased in AS plaque and supernatant of foam cells,while IL-10 was decreased.3.mi R-21 may suppress the inflammation of AS by targeting PDCD4 thus plays a critical and protective role in AS.