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OBJECTIVE: To investigate the role of exosomal miRNA-133 secreted by cardiac fibroblasts (CFs) in promoting cardiomyocyte differentiation. METHODS: Neonatal rat CFs were cultured in vitro, and the cultured CFs were divided into three groups as follows: induction, miRNA-133 high expression, and miRNA-133 inhibition. miRNA-133 was transfected into CFs with lentivirus as a vector. CFs were transfected with the miRNA-133 inhibitor, and the markers of cardiomyocyte were detected through immunofluorescence staining, Western blotting, and real-time quantitative polymerase chain reaction (qRT-PCR) at 3, 8, and 14 days, respectively. The expression levels of cardiac troponin T (cTnT) and cardiac actin (α-actin) were determined, and qRT-PCR was used to detect the expression of miRNA-133 in the fibroblast exosomes. RESULTS: CFs subjected to immunofluorescence staining expressed vimentin and discoid domain receptor 2. The exosomes secreted by CFs were observed as small vesicles of 30-100 nm via transmission electron microscopy, and Western blotting was used to detect exosome-specific protein CD63 and CD9 expression. The expression levels of cTnT, α-actin, and exosomal miRNA-133 secreted into the supernatant of the miRNA-133 high-expression group increased gradually at different time points and reached the highest level at 14 days. The expression levels of cTnT, α-actin, and exosome miRNA-133 in the miRNA-133 inhibition group were the lowest. CONCLUSION: The exosomal miRNA-133, which is derived from CFs, can promote the differentiation of fibroblasts into cardiomyocyte-like cells.
Subject(s)
MicroRNAs , Actins/genetics , Actins/metabolism , Animals , Fibroblasts/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , Myocytes, Cardiac/metabolism , RatsABSTRACT
Objective To investigate the effect of hosphocreatine therapy on the plasma cardiotrophin-1(CT-1) and N terminal probrain natriuretic (NT-proBNP) in elderly hypertensive patients with heart failure. Methods A total of 76 hy-pertensive patients with heart failure, aged 65 or over, were randomly divided into treatment group and control group (n=38 for each group). The control group received routine anti-heart failure treatment. The treatment group received conventional therapy plus creatine phosphate sodium for 2 weeks. The plasma levels of CT-1 and NT-proBNP were determined in two groups. The plasma CT-1 level was measured by a double antibody sandwich enzyme-linked immunosorbent assay (ELISA). The plasma level of NT-proBNP was tested by Rui Pu fluorescent dry quantitative analyzer. Results The plasma levels of CT-1 and NT-proBNP were significantly lower after treatment in two groups (P＜0.01). The plasma levels of CT-1 and NT-proBNP were significantly decreased in treatment group than those in control group (P＜0.05). The total effective rate was 89.47%in treatment group, which was significantly higher than that of control group (71.05%, P＜0.05). Symptoms of heart failure improved in one week (21 cases in treatment group/9 cases in control group) and in two weeks (13 cases in treatment group/18 cases in control group). Conclusion The conventional therapy plus creatine phosphate sodium can decrease the plasma CT-1 and NT-proBNP levels in elderly hypertensive patients with heart failure, which improves symptoms of heart failure in a shorter period of time.
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@#ObjectiveTo explore the effect of the Breviscapine (Bre) on rabbit's cardiac muscles after ischemic preconditioning (IP).MethodsThe myocardial ischemic reperfusion model was made with 32 New Zealand white rabbits by silk thread passed around the left circumflex coronary artery and the apex. Model animals were randomly divided into four groups: myocardial ischemia-reperfusion (I/R) group, Bre+I/R group, IP group and Bre+IP group. The changes of the endothelin (ET), nitrous oxide (NO) and the enzymes of the cardiac muscle were measured, and the areas of myocardium infarction were analyzed.ResultsBre and IP could decrease the content of ET, the enzymes of the cardiac muscle and myocardial infarction area; increase the content of the NO. Bre+IP could strengthen the role of protecting the ischemic myocardial cells.ConclusionThe Bre can protect the ischemic cardiac muscle. The Bre+IP can strengthen the protective effect of the IP.
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Objective To research pacemaker cells outside conductive system of rat and mouse heart. Methods Paraffin and frozen serial sections (stained with HE, Masson, cholinesterase technique), and ultrastructural sections, from atrial tissue of 10 rats and 15 mice were observed by light and electron microscopy to find latent pacemaker-like cells. Results Some round or elliptical cells were scattered and irregularly detected in right and left atrial tissue of rat and mouse. Their nuclei were larger, plasma was clearer and cellular organelles were fewer than those of working myocyte. These cells were similar to pacemaker cells in sinoatrial node.Conclusion There are some pacemaker-like cells in right and left atrial tissue of rat and mouse. The finding can provide a morphological basis for ectopic beat of atrium.
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Objective To study the regularities of myocardiac cells with age increasing. Methods 30 male rats were used in the experiment and divided into three groups:infant group (20\|25 day), young group (3\|5 month) and old group (13\|15 month). Routine paraffine sections were made for PTAH staining and data of cell area, nuclear area, ratio of nucleus to cytoplasm, nuclear ellipticity were measured by image computer analyzer. Results With advancing age:1^Cell area and nuclear area became larger; the ratio of nucleus to cytoplasm was declined; nuclear ellipticity turned high. 2^The cell area of ventricular myocytes was bigger than that of atrial myocytes, the cell area of left atrial myocytes and left ventricular myocytes was bigger than that of right ones, and the cell area of interventricular septum was between that of right ventricular myocytes and left ones. 3^Myocardiac cells became thicker and longer; intercalated disc got distinct and complex.Conclusion The growth of nuclei seem to slower than that of myocardiac cells; the morphology of nucleus changes from round to ellipse; Round nucleus is one of important features of young cells; the cells in atrium is younger than that of ventricle.
