Clinical significance and correlation of microRNA-21 expression and the neutrophil-lymphocyte ratio in patients with acute myocardial infarction.

OBJECTIVES: To explore the clinical significance and correlation of microRNA-21 (miR-21) and the neutrophil-lymphocyte ratio (NLR) in patients with acute myocardial infarction (AMI). METHODS: The observation group contained 184 patients, while the control group contained 150 patients. The expression of miR-21 in the serum of each group was detected by qRT-PCR. RESULTS: A total of 184 patients and their family members were followed-up for 30 days, among which 35 patients died and 149 patients survived, resulting in a survival rate of 80.97%. According to univariate analysis, there were significant differences in age, cardiac troponin (cTn), heart rate, Killip grade, percutaneous coronary intervention (PCI) operation rate, miR-21 and NLR. In the receiver operating characteristic (ROC) analysis, the area under the curve (AUC) values of miR-21 and NLR for the diagnosis of AMI were 0.909 and 0.868, respectively, and the area under the combined detection curve was 0.960. In the Kaplan-Meier survival analysis, the survival of patients with high miR-21 expression and NLR was significantly higher than that of patients with low miR-21 expression and NLR (p=0.027; p=0.001). The correlation showed that miR-21 expression in serum was positively correlated with the NLR in the observation group (r=0.528, p<0.05). cTn, heart rate, Killip classification, PCI operation rate, miR-21, NLR are independent risk factors for AMI. CONCLUSION: miR-21 and NLR play a role in the diagnosis of AMI and can be used as predictors for the survival of AMI.

Adipose-derived mesenchymal stem cells attenuate ischemic brain injuries in rats by modulating miR-21-3p/MAT2B signaling transduction.

AIM: To explore the mechanism underlying the protective effect of adipose-derived mesenchymal stem cells (ADMSCs) against ischemic stroke by focusing on miR-21-3p/MAT2B axis. METHODS: Ischemic brain injury was induced in 126 rats by middle cerebral artery occlusion (MCAO). The effect of ADMSC administration on blood-brain barrier (BBB) condition, apoptosis, inflammation, and the activity of miR-21-3p/MAT2B axis was assessed. The role of miR-21-3p inhibition in the function of ADMSCs was further validated in in vitro neural cells. RESULTS: ADMSCs administration improved BBB condition, inhibited apoptosis, and suppressed inflammation. It also reduced the abnormally high level of miR-21-3p in MCAO rats. Dual luciferase assays showed that miR-21-3p directly inhibited the MAT2B expression in neural cells, and miR-21-3p inhibition by inhibitor or ADMSC-derived exosomes in neurons attenuated hypoxia/reoxygenation-induced impairments similarly to that of ADMSCs in vivo. CONCLUSION: This study confirmed the protective effect of ADMSCs against ischemic brain injury exerted by suppressing miR-21-3p level and up-regulating MAT2B level.

Clinical significance and correlation of microRNA-21 expression and the neutrophil-lymphocyte ratio in patients with acute myocardial infarction

OBJECTIVES: To explore the clinical significance and correlation of microRNA-21 (miR-21) and the neutrophil-lymphocyte ratio (NLR) in patients with acute myocardial infarction (AMI). METHODS: The observation group contained 184 patients, while the control group contained 150 patients. The expression of miR-21 in the serum of each group was detected by qRT-PCR. RESULTS: A total of 184 patients and their family members were followed-up for 30 days, among which 35 patients died and 149 patients survived, resulting in a survival rate of 80.97%. According to univariate analysis, there were significant differences in age, cardiac troponin (cTn), heart rate, Killip grade, percutaneous coronary intervention (PCI) operation rate, miR-21 and NLR. In the receiver operating characteristic (ROC) analysis, the area under the curve (AUC) values of miR-21 and NLR for the diagnosis of AMI were 0.909 and 0.868, respectively, and the area under the combined detection curve was 0.960. In the Kaplan-Meier survival analysis, the survival of patients with high miR-21 expression and NLR was significantly higher than that of patients with low miR-21 expression and NLR (p=0.027; p=0.001). The correlation showed that miR-21 expression in serum was positively correlated with the NLR in the observation group (r=0.528, p<0.05). cTn, heart rate, Killip classification, PCI operation rate, miR-21, NLR are independent risk factors for AMI. CONCLUSION: miR-21 and NLR play a role in the diagnosis of AMI and can be used as predictors for the survival of AMI.

Roles of MicroRNA-195 in cardiomyocyte apoptosis induced by myocardial ischemia-reperfusion injury.

This study aims to investigate microRNA-195 (miR-195) expression in myocardial ischaemia-reperfusion (I/R) injury and the roles of miR-195 in cardiomyocyte apoptosis though targeting Bcl-2. A mouse model of I/R injury was established. MiR- 195 expression levels were detected by real-time quantitative PCR (qPCR), and the cardiomyocyte apoptosis was detected by TUNEL assay. After cardiomyocytes isolated from neonatal rats and transfected with miR-195 mimic or inhibitor, the hypoxia/reoxygenation (H/R) injury model was established. Cardiomyocyte apoptosis and mitochondrial membrane potential were evaluated using flow cytometry. Bcl-2 and Bax mRNA expressions were detected by RT-PCR. Bcl-2, Bax and cytochrome c (Cyt-c) protein levels were determined by Western blot. Caspase-3 and caspase-9 activities were assessed by luciferase assay. Compared with the sham group, miR-195 expression levels and rate of cardiomyocyte apoptosis increased significantly in I/R group (both P < 0.05). Compared to H/R + negative control (NC) group, rate of cardiomyocyte apoptosis increased in H/R + miR-195 mimic group while decreased in H/R + miR-195 inhibitor group (both P <0.05). MiR-195 knockdown alleviated the loss of mitochondrial membrane potential (P <0.05). MiR-195 overexpression decreased Bcl-2 mRNA and protein expression, increased BaxmRNA and protein expression, Cyt-c protein expression and caspase-3 and caspase-9 activities (all P <0.05).While, downregulated MiR-195 increased Bcl-2 mRNA and protein expression, decreased Bax mRNA and protein expression, Cyt-c protein expression and caspase-3 and caspase-9 activities (all P < 0.05). Our study identified that miR-195 expression was upregulated in myocardial I/R injury, and miR-195 overexpression may promote cardiomyocyte apoptosis by targeting Bcl-2 and inducing mitochondrial apoptotic pathway.