ABSTRACT
Objective:To investigate the changes of cardiomyocyte apoptosis after hypoxia/reoxygenation (H/R) regulated by microRNA-1 (miR-1).Methods:Cardiomyocyte strain H9c2 derived from rat embryonic heart tissue were cultured in vitro. The cells in logarithmic growth phase were divided into blank control group, H/R group, miR-1 mimics+H/R group, miR-1 inhibitor antisense oligonucleotide (ASO)+H/R group and microRNA negative control fragment (miRNA NC)+H/R group. The low sugar DMEM medium containing low concentration of fetal bovine serum (FBS) was used as the medium under anoxic condition. After being cultured in a closed anaerobic incubator at 37 ℃ (95% N 2 and 5% CO 2) for 12 hours, the cells were cultured with the fresh high sugar DMEM medium containing 5% FBS in a closed incubator at 37 ℃ for reproducing cardiomyocyte H/R model. The blank control group was cultured in high glucose DMEM medium containing 10% FBS in 37 ℃ and 5% CO 2 incubator. In miR-1 mimics+H/R group, miR-1 ASO+H/R group and miRNA NC+H/R group, the corresponding transfectants were mixed in high glucose DMEM medium and transfected into cells before H/R model was established, and the final concentration was 50 nmol/L. The blank control group and H/R group were added with DMEM medium at the same time. After the establishment of the model, the expression level of miR-1 was detected by real-time fluorescence quantitative polymerase chain reaction (qPCR). The expression levels of apoptosis-related proteins caspase-9, Bcl-2 and Bax were detected by Western blotting, and cardiomyocyte apoptosis was detected by flow cytometry. Results:Compared with the blank control group, the expression levels of miR-1, caspase-9 and Bax protein and the apoptosis rate of cardiomyocytes were significantly increased, while the expression level of Bcl-2 was significantly decreased, which indicated that the expression of miR-1 and the level of apoptosis were increased in H/R group. Compared with H/R group, the expressions of miR-1, caspase-9 and Bax and the apoptosis rate of cardiomyocytes in miR-1 mimics+H/R group were further increased [miR-1 (2 -ΔΔCt): 11.59±1.48 vs. 2.57±0.38, caspase-9 protein (caspase-9/β-actin): 2.59±0.12 vs. 1.56±0.20, Bax protein (Bax/β-actin): 4.09±0.38 vs. 1.97±0.13, apoptosis rate: (25.23±0.87)% vs. (17.86±0.73)%, all P < 0.01], while the expression of Bcl-2 was decreased (Bcl-2/β-actin: 0.37±0.02 vs. 0.49±0.03, P < 0.01). The expressions of miR-1, caspase-9 and Bax and the apoptosis rate were significantly decreased in miR-1 ASO+H/R group [miR-1 (2 -ΔΔCt): 1.16±0.06 vs. 2.57±0.38, caspase-9 protein (caspase-9/β-actin): 1.05±0.24 vs. 1.56±0.20, Bax protein (Bax/β-actin): 0.93±0.11 vs. 1.97±0.13, apoptosis rate: (11.19±0.85)% vs. (17.86±0.73)%, all P < 0.05], while the expression of Bcl-2 was increased (Bcl-2/β-actin: 0.84±0.17 vs. 0.49±0.03, P < 0.05). There was no significant difference in miR-1 expression, caspase-9, Bax and Bcl-2 protein expressions, and apoptosis rate between H/R+miRNA NC group and H/R group. Conclusion:The expression of miR-1 and level of apoptosis were increased in H/R cells, and miR-1 could aggravate cardiomyocyte apoptosis.
ABSTRACT
Objective To study the multi-slice spiral CT (MSCT) manifestations of septic pulmonary embolism(SPE) in order to get a better understanding of the disease,Methods The MSCT manifestations of 12 patients with septic pulmonary embolism were retrospectively analyzed and compared with chest radiograph.Results Of the 12 patients,Chest radiograph and CT scanning showed multiple peripheral pulmonary nodules in 8 and 12 cases,a feeding vessel sigu(0,9 cases),cavitations(6,10 cases) and wedge-shaped opacities(4,7 cases),focal infiltrates(2,4 cases),air cyst(2,5 cases),pleural lesions (3,6 cases),hilar or mediastinal lymphadenopathy(0,3 cases).Peripheral or subpleural zones were most commonly affected (8,12 cases).CT was more useful in revealing nodules and a feeding vessel sign.Multiplanar reconstructions (MPR),maximum intensity projection (MIP) showed that most of these vessels passed around nodules and wedge-shaped lesions.MPR showed regular nodular margin.Conclusion SPE presents with variable and often nonspecific clinical and radiographic features.MPR and MIP showed the features of nodules and feeding vessels better.The diagnosis is usually suggested by the presence of a predisposing factor,febrile illness,and CT findings of multiple,periphery pulmonary nodules,with orwithout cavitation and a feeding vessel sign.