Expression changes and significance of miR-155 in peripheral blood mononuclear cells of patients with dilated cardiomyopathy

YAN Xiao-fei; HUANG Liang; YAN Lian-hua; HU Fen; WANG Ya; MA Wen-han; LU Shuai; WHANG Zhao-hui

doi:10.3969/j.issn.1002-266X.2015.32.007

Abstract：Objective To observe the expression changes of microRNA-155 ( miR-155) in the peripheral blood mono-nuclear cells ( PBMC) of patients with dilated cardiomyopathy ( DCM) and to explore the relationship between miR-155 level and heart function .Methods Thirty patients with DCM ( observation group ) and 30 healthy volunteers ( control group) were selected.In the observation group , 10 cases were grade Ⅱof NYHA functional classification , 11 cases were grade Ⅲand 9 cases were grade Ⅳ.PBMC in the two groups were separated by Ficoll-Hypaque density gradient centrifuga-tion, and the relative expression of miR-155 was detected by real-time fluorescence quantitative PCR .The miR-155 levels were compared between the observation group and the control group and among DCM patients with different NYHA function -al classification.In the observation group, the left ventricular ejection fraction (LVEF) and left ventricular end diastolic diameter ( LVEDd ) were recorded by color Doppler ultrasound .The relationships between miR-155 levels and LVEF , LVEDd were analyzed in DCM patients .Results The relative expression levels of miR-155 in the observation group and control group were (0.50 ±0.24) and (1.00 ±0.23), which showed a significant difference (P<0.01).The relative expression levels of miR-155 in NYHA functional classification Ⅱ,Ⅲ,ⅣDCM patients were (0.77 ±0.10), (0.47 ± 0.10) and (0.23 ±0.08), respectively.There were significant differences between each two groups (all P<0.01).In the observation group , the LVEF was 28%±10%, and the LVEDd was (70 ±7) mm.The miR-155 level was negatively correlated with NYHA functional classification , LVEF and LVEDd in DCM patients ( r=-0.94, -0.67 and -0.53, P<0.05 or P<0.01).Conclusions The expression level of miR-155 is down-regulated in PBMC of DCM patients and is correlated with the severity of impaired cardiac function .