Effect Of Mirna-146 Expression On Inflammatory Responses In Elderly Patients With Acute Myocardial Infarction And In Vitro

The study objective was to detect the expression of miRNA-146 in the serum of elderly patients with myocardial infarction and investigate the effect of its expression on the inflammatory response of peripheral blood in elderly patients with AMI and in vitro. Fluorescent quantitative PCR was performed to detect miRNA-146 expressions in the serums of 39 cases of elderly AMI patients, 21 cases of elderly Unstable angina (UA) patients and 21 cases of healthy elderly people (HE) that were admitted in our hospital from May 2016 to November 2016. The relationships between serum miRNA-146 expression and inflammatory factors such as serum CRP and TNF-alpha were analyzed. PBMC was isolated from peripheral blood of elderly patients with AMI, and the expression of miRNA-146 was upregulated by transfection of miRNA-146 mimic. Western blot was performed to detect the effect of miRNA-146 over expression on the expressions of SIRT1 and P65 proteins. The relative expressions of serum miRNA-146 in elderly AMI patients, elderly UA patients and healthy elderly people were (1.14 +/- 0.20), (0.32 +/- 0.056) and (0.19 +/- 0.039), respectively, and the differences between groups were statistically significant (P<0.05). The relative expression of serum miRNA-21 in elderly AMI patients was negatively correlated with serum CRP (r = -0.637, P<0.001) and TNF-alpha (r = -0.626, P<0.001). Transfection of miRNA-146 mimic up-regulated the expression of miRNA-146 in PBMC, which increased the expression of SIRT1 protein by 2.65 times while decreased the expression of nuclear p65 protein by 47.92% and the exocrine TNF-alpha by 57.77%. miRNA-146 was highly expressed in the serum of elderly AMI patients, which inhibited the inflammatory response of peripheral blood mononuclear cells in elderly AMI patients by inhibiting the NF-kB signaling pathway, thereby protecting the cardiomyocytes.