Identification and function analysis of differentially expressed miRNAs in rat myocardial infarction model / 中国药理学通报

Aim To identify differentially expressed microRNAs (miRNAs) in rat myocardial infarcted tissues and predict their interaction with IncRNAs and target genes, as well as to explore potential pathophysiology mechanisms in myocardial infarction. Methods A rat model of myocardial infarction was established by ligating the left anterior descending coronary artery. Trizolwas used to extract total RNA from infarcted myocardial area for microarray detection. Bioinformatics methods were used to predict interaction IncRNAs, target genes, and functional enrichment of miRNAs thatwere significantly differently expressed. The possible IncRNA-miRNA-mRNA regulatory networks were identified finally. Results The elevation of ST segment of ECG showed that the rat model of myocardial infarction was successfully prepared. Microarray results showed that there were 19 significantly differently expressed miRNAs. Eight of these miRNAs (miR-21, miR-132, miR-222, miR-223-3p, miR-146a/b, miR-181b, miR-449a-5p, miR-122) were proven to be myocardial infarction treatment candidates. Whether seven miR-NAs (miR-365-5p, miR490-5p, miR-6333, miR-30cl-3p, miR-3591, miR-3596c, miR-877) were related to myocardial infarction called for further confirmation. There might be several new IncRNA-miRNA-mRNA mechanisms in the development of myocardial infarction. ENSRNOT00000076620-miR-146b-5p-STAT3/Rnf7/Qrsll may be involved in the process of cardiomyocyte apoptosis and mitochondrial damage during myocardial infarction. ENSRNOT00000071991-miR-122-Deptor might inhibit the autophagy of cardiomyocytes and exacerbate myocardial infarction. Conclusions The ternary relationship of IncRNA-miRNA-mRNA obtained in this study may provide possible research directions and a certain theoretical basis for further exploration of the molecular level pathological mechanism of myocardial infarction, and new therapeutic targets for myocardial infarction as well.

Effects of bisoprolol pretreatment on hypoxia/reoxygenation-induced injury in H9c2 cardiomyocytes / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigated the effects of bisoprolol pretreatment on hypoxia/reoxygenation (H/R)-induced injury in H9c2 cardiomyocytes.</p><p><b>METHODS</b>Cultured H9c2 cells were exposed to hypoxia for 6 h followed by reoxygenation for 2 h with or without pretreatments with bisoprolol or bisoprolol + LY294002. The cell survival was measured by MTT assay, and the cell apoptosis and levels of radical oxygen species (ROS) were evaluated with flow cytometry. The protein levels of phosphyorylated AKT and phosphorylated GSK3β in the cells were determined by Western blotting.</p><p><b>RESULTS</b>Compared with the normal control cells, the cells exposed to H/R injury showed significantly decreased cell survival and increased cell apoptosis and ROS production; pretreatment of the cells with bisoprolol significantly decreased the cell apoptotic rates and ROS production and obviously enhanced the cell survival and protein levels of p-AKT and p-GSK3β in the exposed cells. The protective effect of bsioprolol against H/R-induced cell injury was significantly attenuated by LY294002.</p><p><b>CONCLUSION</b>Bisoprolol can protect H9c2 cells against H/R-induced injury and oxidative stress by activating PI3K/AKT/Gsk-3β pathway to increase the phosphorylation of AKT and GSK3β and reduce ROS production.</p>

Membrane testosterone receptors in cultured vascular smooth muscle cells / 中华男科学杂志

<p><b>OBJECTIVE</b>To determine the presence of membrane testosterone receptors in cultured vascular smooth muscle cells (VSMC), and investigate their relationship with classical intracellular androgen receptors (iAR).</p><p><b>METHODS</b>VSMCs were cultured from the thoracic aorta of male Sprague-Dawley rats by the explant method. Subconfluent VSMCs were incubated with serum-free medium for 24 h to obtain quiescent non-dividing cells, and then treated with the indicated agents. The aliquots of VSMCs were labeled with testosterone-BSA-FITC (T-BSA-FITC) and analyzed by flow cytometry. Classical iARs in intact- and permeabilized-cells were detected with anti-iAR antibodies and FITC-labeled secondary antibodies by immunofluorescence, followed by flow cytometry analysis.</p><p><b>RESULTS</b>Incubation of VSMCs with T-BSA-FITC obviously increased their relative fluorescence intensity at 10 sec as compared with the untreated controls (P < 0.01), and so did it at 10 min in comparison with the treatment with BSA-FITC alone or together with free testosterone (P < 0.01). Pretreatment with iAR antagonist flutamide exhibited no significant influence on the relative fluorescence intensity of VSMCs (P = 0.318). Traditional iARs were not detectable on the surface of intact VSMCs, although permeabilized cells contained iARs.</p><p><b>CONCLUSION</b>VSMCs contain testosterone receptors in the plasma membrane, and these membrane receptors are not identical to classical iARs.</p>

Testosterone at physiological level inhibits PGF2alpha-induced increase in intracellular Ca2+ in cultured vascular smooth muscle cells / 中华男科学杂志

<p><b>OBJECTIVE</b>To explore the acute effects of testosterone at the physiological level on PGF2alpha-induced increase in intracellular Ca2+ in cultured vascular smooth muscle cells (VSMCs).</p><p><b>METHODS</b>VSMCs from the thoracic aorta of male Sprague-Dawley rats were cultured using the explant method. The subconfluent VSMCs were incubated with serum-free medium for 24 hours to obtain quiescent non-dividing cells and then treated with the indicated agents. For the measurement of [Ca2+]i, the VSMCs were loaded with fura-2. Changes of [Ca2+]i were determined ratiometrically with a Nikon TE-2000E system.</p><p><b>RESULTS</b>The resting level of [Ca2+]i was around 100 nmol/L in the VSMCs. Exposing cells to perfusate containing 10 micromol/L PGF2alpha triggered an immediate and transient peak in [Ca2+]i, which gradually decreased afterwards. Interference at the peak with the physiological concentration (40 nmol/L) of testosterone significantly decreased the peak-to-baseline time of [Ca2+]i, compared with ethanol vehicle (104.9 +/- 27.0 s vs 153.5 +/- 40.4 s, P < 0.01). Pretreatment with testosterone at 40 nmol/L for 2 minutes also reduced the peak-to-baseline time of [Ca2+]i significantly in comparison with the ethanol control (120.6 +/- 32.0 s vs 151.4 +/- 27.4 s, P < 0.01), but it had no significant effect on the peak level of PGF2alpha-induced intracellular Ca2+ (390.0 +/- 126.0 nmol/L vs 403.4 +/- 160.7 nmol/L, P > 0.05).</p><p><b>CONCLUSION</b>Testosterone at physiological concentration inhibits PGF2alpha-induced Ca2+ fluxes, probably via receptor-operated calcium channels by a non-genomic mechanism in VSMCs, which may be involved in the vasodilatory effect of testosterone.</p>

Coronary artery lesion comparison between Chinese and Australian patients with coronary artery disease / 中华心血管病杂志

<p><b>OBJECTIVE</b>To compare coronary lesion characteristics by coronary angiography (CAG) between yellows and whites.</p><p><b>METHODS</b>CAG results of 3021 Chinese patients, defined as yellows, from Nanjing and 3230 Australian patients, defined as whites, from Sydney were analyzed. The coronary artery lesion was evaluated by the number and location of coronary lesion and Gensini scores.</p><p><b>RESULTS</b>(1) Coronary stenosis was diagnosed in 69.4% Chinese patients and 75.5% in Australians. The involved coronary arteries were left anterior descending branch, right coronary artery, left circumflex branch and left main coronary artery in a descending order in both Chinese and Australians. (2) The incidences of three-vessel disease and left main disease of yellows were significantly lower than that of whites in both male (29.8% vs. 34.0% and 9.6% vs. 14.2%) and female patients (15.8% vs. 26.2% and 4.9% vs. 11.6%) respectively, all P < 0.05. (3) There was an age-dependent Gensini scores increase in both yellows and whites patients and Gensini scores at age 40 and more of whites were significantly higher than those of yellows in comparable age groups.</p><p><b>CONCLUSION</b>The incidences of three-vessel disease and left main disease as well as Gensini score were significantly higher in Australian patients than those of Chinese patients.</p>

Evaluation of regional myocardial function after coronary stenting pulsed wave Doppler tissue imaging / 医学研究生学报

Objective: To assess the regional systolic and diastolic function of left ventricle before and after coronary stent implantation by pulsed wave Doppler tissue imaging (PW-DTI). Methods: Twenty-six patients with coronary artery disease ( CAD) involving only left anterior descending coronary artery ( LAD) were examined within 1-3 days before, 7 days and 30 days after coronary stenting with PW-DTI. Peak systolic , peak early diastolic, and peak late diastolic motion velocities ( Sm, Em, and Am respectively) were measured at 6 different sites on the basal and medial segments corresponding to the anteroseptal, postero-septal, lateral, anterior, inferior, and posterior walls of the left ventricle. Results:In corresponding segments depending on LAD blood flow supply, Sm was increased significantly 7 days after the stenting proce- dure. Em was also increased 7 days after the procedure in most of the corresponding segments. There were little changes in other segments that were independent on LAD blood flow supply. Conclusion: These findings suggest that there is an early improvement in the regional systolic and diastolic function of the left ventricle after the coronary stenting, and that PW-DTI techniques could evaluate quantitatively the regional ventricular performance in patients receiving percutaneous coronary intervention.