Influence of miR-34a on myocardial apoptosis in rats with acute myocardial infarction through the ERK1/2 pathway.

OBJECTIVE: To study the influence of micro-ribonucleic acid (miR)-34a on myocardial apoptosis in rats with acute myocardial infarction (AMI) through the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway. MATERIALS AND METHODS: A total of 24 Sprague-Dawley (SD) rats were randomly divided into sham group (n=12) and model group (n=12). The heart was exposed in the sham group, while the AMI model was established in the model group. After sampling, the morphology of myocardial tissues was observed via hematoxylin-eosin (HE) staining, the expressions of B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax) were detected via immunohistochemistry, and the protein expression levels of ERK1/2 and phosphorylated ERK1/2 (p-ERK1/2) were detected via Western blotting. Moreover, the expression of miR-34a was detected via quantitative Polymerase Chain Reaction (qPCR), the apoptosis was detected via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), and the myocardial injury indexes were detected using a fully-automatic biochemical analyzer. RESULTS: The morphology of myocardial tissues was normal with a complete structure in the sham group, while there was damage to myocardial tissues in different degrees in the model group. The immunohistochemical results revealed that the Bax expression was increased and the Bcl-2 expression was decreased in the model group compared with those in the sham group (p<0.05). The results of Western blotting showed that the protein expression levels of both ERK1/2 and p-ERK1/2 were significantly increased in the model group compared with those in the sham group (p<0.05). The qPCR results manifested that the expression of miR-34a in the model group markedly declined compared with that in the sham group (p<0.05). Besides, the TUNEL detection showed that the apoptosis rate in the model group was remarkably increased compared with that in the sham group (p<0.05), and the content of cardiac troponin T and creatine kinase isoenzyme in the model group was significantly higher than that in the sham group ((p<0.05). CONCLUSIONS: MiR-34a affects the apoptosis in AMI by regulating the ERK1/2 signaling pathway.

Correlation of hypertension and F2RL3 gene methylation with Prognosis of coronary heart disease.

The aim of this work was to investigate the correlation between methylation of F2RL3 gene and coronary heart disease (CHD) with or without hypertension, secondary cardiovascular events and mortality. Sixty patients with CHD who underwent a cardiovascular rehabilitation program were recruited. Group A included 30 patients with hypertension and CHD, and group B included 30 patients with non-hypertensive CHD, followed-up for more than 8 years. F2RL3 gene methylation was characterized by Sequenom matrix assisted laser desorption ionization time flight mass spectrometry. The correlation between methylation of the F2RL3 gene, hypertension and secondary cardiovascular events and all-cause mortality was analyzed by multivariate Cox, regression models that estimated confounders to control risk ratios. The results showed that during the follow-up, 3 patients in Group A developed non-fatal stroke, 2 patients died of cardiovascular disease, 1 patient died of other causes, and 4 patients in Group B developed non-fatal myocardial infarction. After adjusting for known prognostic factors, Cox model analysis showed that methylation of F2RL3 gene was closely related to hypertension and mortality. After F2RL3 included in the regression model, the correlation between hypertension and all prognostic outcomes increased. In conclusion, the methylation of F2RL3 can affect the prognosis of different types of acute coronary syndrome and is closely related to mortality.

MiR-210 protects cardiomyocytes from OGD/R injury by inhibiting E2F3.

OBJECTIVE: To detect the change in miRNA-210 expression of cardiomyocytes under hypoxia/reoxygenation status. Also, the effect of miR-210 on the apoptosis of cardiomyocytes induced by oxygen-glucose deprivation/reperfusion (OGD/R) and its mechanism through establishing the OGD/R injury model of primary cardiomyocytes in this experiment were investigated. MATERIALS AND METHODS: The cell model of OGD/R injury was established. The cell apoptosis in each group was detected by methyl thiazolyl tetrazolium (MTT) assay and detection of Caspase-3 activity. The change in miR-210 expression in each group was detected by Real-time fluorescence quantitative polymerase chain reaction (PCR). The high-expression and low-expression miR-210 models were established through the transient transfection of miR-210 mimic and inhibitor to detect the relevant indexes of cell apoptosis. At the same time, changes in mRNA and protein expressions of E2F3 were detected by RT-PCR and Western blotting, respectively. The E2F3 overexpression vector was constructed, and the overexpression vector plasmid and miR-210 mimic were jointly transfected into the cells to detect the relevant indexes of cell apoptosis. RESULTS: After OGD/R treatment, the activity of Caspase-3 was increased, the survival of cardiomyocytes was significantly inhibited and the expression level of miR-210 was up-regulated in OGD/R injury. Transfection of miR-210 mimic for miR-210 overexpression could alleviate the OGD/R-induced cardiomyocyte injury, while the decrease of miR-210 expression could aggravate the apoptosis of cardiomyocytes. In addition, the high expression of miR-210 could inhibit the protein expression of E2F3, and co-transfection of E2F3 plasmid and miR-210 mimic could reverse the inhibiting effect of miR-210 on the apoptosis of cardiomyocytes. CONCLUSIONS: We confirmed that miR-210 can inhibit the OGD/R-induced apoptosis of cardiomyocytes, and miR-210, as an upstream factor, plays a protective role in cardiomyocytes through directly inhibiting the protein expression of its target gene E2F3.

Remission effect of vitamin C on isoflurane-induced apoptosis and its mechanism.

This study aims to discuss the remission effect of vitamin C on isoflurane-induced apoptosis of rats and its possible mechanism of action, to provide a theoretical basis for postoperative cognitive impairment. Reactive oxygen species (ROS) detection, adenosine triphosphate (ATP) test, MTT method and Morris water maze were applied for detection tests. For data statistics, double factor analysis of variance (ANOVA) and post hoc Bonferroni test were adopted. It was found that vitamin C could slow down the isoflurane-induced accumulation of ROS in H4-APP cells; moreover, it could relieve the activation of caspase-3 and increase cell survival rate to inhibit the occurrence of apoptosis, indicating that ROS was the source of cell toxicity. On the other hand, vitamin C could protect the cells with its antioxidant effect. It was proved that vitamin C could remit isoflurane-induced apoptosis and relieve the decline in learning and memory ability of rats.