The mechanism of miR-142-3p in coronary microembolization-induced myocardiac injury via regulating target gene IRAK-1

Fig. 1. Downregulation of miR-142-3p in the myocardiac tissue of CME pig. a Echocardiographic analysis of Sham and CME pigs. Left ventricle ejection fraction (LVEF, %), left ventricle fractional shortening (LVFS, %), cardiac output (CO, L/min) and left ventricular end-diastolic diameter (LVEDd, mm) were quantitatively analyzed (n = 10). b Hematoxylin and eosin (H&E) staining of local micro-infracted lesions in the myocardium in the CME group. Arrow indicates microspheres (×400) (n = 10). c Hematoxylin-basic fuchsin-picric acid (HBFP) staining of samples from the Sham, and CME groups. Ischemic myocardium appeared in red. Arrow indicated a micro-infracted lesion (×200) (n = 10). d Relative expression of miR-142-3p was determined by quantitative real-time polymerase chain reaction (qRT-PCR) in the heart (n = 10). e The correlation between miR-142-3p levels and LVEF (%) (n = 10). *P < 0.05

Fig. 2. miR-142-3p agomiR improves cardiac function and attenuates CME-caused myocardiac inflammatory response. a Relative miR-142-3p expression level was increased in the hearts of pigs after miR-142-3p agomiR treatment as determined by quantitative real-time polymerase chain reaction (qRT-PCR) (n = 5). b Left ventricle ejection fraction (LVEF, %), left ventricle fractional shortening (LVFS, %), cardiac output (CO, l/min) and left ventricular end-diastolic diameter (LVEDd, mm) were measured by echocardiography (n = 5). c Hematoxylin-basic fuchsin-picric acid (HBFP) staining of samples from the negative control (NC) agomiR + Sham, miR-142-3p agomiR + Sham, NC agomiR + CME, and miR-142-3p agomiR + CME groups, respectively. Ischemic myocardium appeared in red. Arrow indicates a micro-infracted lesion (×200) (n = 5). d Western blot detection and quantification were performed for NF-κB p65, TNF-α, IL-1β, and IL-6. GAPDH was used as an internal control (n = 5). *P < 0.05; **P < 0.01; ***P < 0.001

Fig. 3. miR-142-3p inhibition aggravates CME-caused myocardiac injury and CME-induced myocardiac inflammatory response. a Relative miR-142-3p expression level was decreased in hearts of pig after miR-142-3p antagomiR treatment as determined by quantitative real time-polymerase chain reaction (qRT-PCR) (n = 5). b Left ventricle ejection fraction (LVEF, %), left ventricle fractional shortening (LVFS, %), cardiac output (CO, l/min) and left ventricular end-diastolic diameter (LVEDd, mm) were measured by echocardiography (n = 5). c Hematoxylin-basic fuchsin-picric acid (HBFP) staining of samples from the negative control (NC) antgomiR + Sham, miR-142-3p antagomiR + Sham, NC antagomiR + CME, and miR-142-3p antagomiR + CME groups, respectively. Ischemic myocardium appeared in red. Arrow indicates a micro-infracted lesion (×200) (n = 5). d Western blot detection and quantification of NF-κB p65, TNF-α, IL-1β and IL-6. GAPDH was used as an internal control (n = 5). *P < 0.05; **P < 0.01; ***P < 0.001

Fig. 4. miR-142-3p directly targets IRAK-1. a Sequence alignment of miR-142-3p and IRAK-1 3′UTR from different species. b Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to determine the expression of IRAK-1 (n = 10). c Western blot detection and quantification for IRAK-1.G APDH was used as an internal control (n = 10). d IRAK-1 was inversely regulated by miR-142-3p at the mRNA level in heart tissues (n = 5). e IRAK-1 was inversely regulated by miR-142-3p at the protein level in heart tissues. GAPDH was used as an internal control (n = 5). f HEK293 cells were transfected with wild-type or mutated IRAK-1 3′UTR together with miR-142-3p agomiR or miRNA negative control (n = 3). *P < 0.05; **P < 0.01; ***P < 0.001

Fig. 5. IRAK-1 mediates the effects of miR-142-3p on inflammation of cardiomyocytes. a Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to determine the expression of miR-142-3p and IRAK-1 (n = 4). b Western blot and quantification were done for determining the IRAK-1, NF-κB p65, TNF-α, IL-1β, and IL-6 expressions. GAPDH was used as an internal control (n = 4). *P < 0.05; **P < 0.01; ***P < 0.001

Fig. 6. Decreased plasma miR-142-3p level in STEMI patients undergoing pPCI with no-reflow. a Quantitative real-time polymerase chain reaction (qRT-PCR) showed that miR-142-3p expression level was decreased in the plasma of STEMI patients undergoing pPCI without no-reflow (n = 214) when compared with STEMI patients undergoing pPCI with no-reflow (n = 41). b The receiver–operator characteristic curve for the plasma miR-142-3p acts as a potential biomarker for STEMI patients undergoing pPCI with no-reflow