Investigation of microrna's and st2 (Growth stimulation expressed gene 2) in pericardial fluid of patients undergoing coronary artery bypass surgery due to coronary artery disease

Many biomarkers related to coronary artery disease (CAD) are transmitted to pericardial fluid (PF) and plasma. In the etiopathogenesis evaluation of CAD, miRNAs can be used diagnostically and soluble ST2 (sST2) can be used prognostically. sST2 is accepted as a biomarker of the ingravescent prognosis in individuals with cardiovascular disease. miRNAs, which play important role in many diseases, are efficient in CAD related endothelial dysfunction, atherosclerosis, inflammation, apoptosis and angiogenesis. PS has potency to reflect cardiac function, and PF concentrations of some substances help to understand many pathophysiological mechanisms. 40 patients having undergone coronary artery bypass operation were included in the study, and gene expression level of group miRNAs (miR-125b-5p, miR-320b, miR- 34a-5p, miR-16-5p, miR-320a and miR-15a-5p) targeting ST2 level with ELISA method and ST2 and ST2 with qRT-PCR method within PF and blood were studied. In our study, mean sST2 value with ELISA was 223.992 ng/ml in PF and 390,357 ng/ml in Plasma, which was found statistically significant (p = 0.0020). The ST2 gene expression level in PF was 2.27 times lower compared to its level in Plasma and this situation was found statistically significant (p = 0.000265). miR16-5p which is said to be 7.35 times lower in PF and miR320b said to be 4.07 times lower were found to be statistically significant within gene expression of miRNAs targeting ST2 (p = 0.000014 and p = 0.00814, respectively). In plasma, negative correlation was found between miR34a-5p and ST2 (r = -0.399, p = 0.039). The reason why protein levels and gene expression of ST2 and gene expression level of miR 16-5p and miR 320b are higher in plasma may be caused by extramyocardial sources. Higher levels of miR 16-5p and miR 320b together with ST2, which have an adverse effect in terms of cardiovascular diseases, and their more frequent expressions in the plasma strengthen their potential to be used as biomarkers. The fact that miR320b, defined as specific to PF in other studies, was also found in plasma, reveals that this miRNA is not only specific to PF.