| Objective: To observe the effect of micro RNA-155(miR-155)on the content of myocardial inflammatory factors in the rats with chronic congestive heart failure(CHF).Methods: The experimental rats were divided into 4 groups randomly : Sham-operated group(sham group,n=10): thoracotomy without ligation of thoracic aorta;Chronic congestive heart failure group(CHF group,n=10): CHF rat model was established by traditional thoracic aortic coarctation operation,and injected with equal volume of normal saline via tail vein;CHF miR-155 inhibitor group(CHF +antagomir group,n=10): CHF model was established and injected with the miR-155 inhibitor antagomir via tail vein;CHF negative nucleotide control group(CHF + miRNA-NC group,n=10): CHF model was established and injected with miR-155 negative control nucleotide via tail vein.After the operation,each group was fed for 8 weeks under the same conditions,while treated with the corresponding intervention 200μl after the establishment of the CHF model by tail vein injection once every 3days for 4 consecutive weeks,and then echocardiography was performed to detect the left ventricular ejection fraction(LVEF),the left ventricular short axis shortening rate(FS),the left ventricular end diastolic diameter(LVEDD),and the left ventricular end systolic diameter(LVESD)in each group.The serum NT-pro BNP level of rats in each group was detected by enzyme-linked immunosorbent assay;Then the left ventricular heart tissue of rats were taken for HE staining;RT-PCR was used to detect the expression of miR-155 in left ventricular myocardium of rats in each group.The expressions of NF-κB P65 protein,p38 MAPK protein,IL-6and TNF-α in left ventricular myocardium of rats in each group were detected by Western blotting.Results: 1.Compared with sham group,the ratio of left ventricular weight to heart weight(LVW/HW)as well as the ratio of heart weight ratio to body weight(HW/BW)of the CHF group were obviously increased,moreover LVEDD and LVESD in CHF group were elevated significantly,while LVEF and FS were reduced distinctly(P<0.05);However,there was no evident difference among the obove parameters of CHF + antagomir group or CHF + miRNA-NC group compared with CHF group(P>0.05).2.The results of enzyme-linked immunosorbent assay showed that serum NT-pro BNP levels in the CHF+antagomir group were significantly lower than those in the CHF group and CHF + miRNA-NC group(P<0.05),nevertheless still higher than those in the Sham group(P>0.05);3.The results of RT-PCR detection reveled that compared with the Sham group,the expression of miR-155 in CHF group and CHF + miRNA-NC group were significantly increased(P<0.05),though there was no drastical difference between these two groups.While that in CHF + antagomir group was obviously decreased compared with the CHF group(P<0.05).4.The results of Western blotting showed that compared with Sham group,the expressions of NF-κB P65 protein,p38 MAPK protein,IL-6 and TNF-α in CHF group were distinctly increased(P<0.05).Moreover,compared with CHF group,the obove parameters of CHF+ miRNA-NC group had no significant changes(P>0.05),whereas the expression of CHF + antagomir group decreased(P<0.05).Conclusion: The expression of miR-155 in left ventricular myocardium of rats with CHF is increased,and the inflammatory response of CHF rats is regulated by p38 MAPK / NF-κB signal transduction pathway possibly. |
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