ABSTRACT
<p><b>OBJECTIVE</b>To investigate the role and signalling of microRNA(miR)-182 on regulating high glucose-induced cardiomyocyte hypertrophy.</p><p><b>METHODS</b>The candidates of miR which might potentially be involved on targeting Rac1 were predicted by applying bioinformatics analysis. The expression of all related candidates miRs was verified by real-time reverse transcription-PCR (RT-PCR) in cardiac tissues of db/db mice and db/m mice. Then the relationship between candidates miR and Rac1 was investigated with Pearson relevant analysis. Neonatal mice cardiomyocytes were cultured and divided into 2 groups: normal glucose group and high glucose group. The level of selected miR and Rac1 in two groups was detected by RT-PCR. Neonatal mice cardiomyocytes were then randomly divided into 4 groups: normal glucose group, selected microRNA mimics control group, high glucose group, high glucose plus selected miR mimics control group. The morphology of cardiomyocyte in each group was detected under light microscope. Furthermore, Rac1, β-MHC and α-SMA expressions were detected in cultured cardiomyocyte treated by high glucose for 48 h after transfecting selected miR mimics by RT-PCR and Western blot.</p><p><b>RESULTS</b>A total of 6 miR candidates potentially targeting Rac1 were screened by bioinformatics, which were miR-182, miR-142-3p, miR-140, miR-101a, miR-429 and miR-200b. Among these candidates, miR-182 and miR-142-3p expression was significantly downregulated in cardiac tissues of db/db mice compared with db/m controls (P < 0.05). MiR-182 was negatively correlated with Rac1 by person analysis (r = -0.891 02). Downregulation of miR-182 and upregulation of Rac1, β-MHC, α-SMA were found in high glucose-induced cardiomyocyte. After transfection of miR-182 mimics, hypertrophic changes were significantly reduced and Rac1 as well β-MHC expression was significantly downregulated in cardiomyocyte incubated with high glucose.</p><p><b>CONCLUSION</b>MiR-182 might be involved in the regulation of high glucose-induced myocardial hypertrophy process via targeting Rac1.</p>
Subject(s)
Animals , Mice , Cardiomyopathy, Hypertrophic , Metabolism , Down-Regulation , Glucose , Physiology , MicroRNAs , Physiology , Myocytes, Cardiac , Metabolism , Neuropeptides , Metabolism , Rats, Sprague-Dawley , Transfection , Up-Regulation , rac1 GTP-Binding Protein , MetabolismABSTRACT
Objective To investigate the effect of 20 kHz low-intensity ultrasound combined with microbubbles on autophagy of both PC3 cells and DU145 cells. Methods Ultrasound with a frequency of 20 kHz and intensity of 80 mW in continuous wave mode was used. Both PC3 cells and DU145 cells were divided into four groups, including control group (A), microbubbles group (B), ultrasound group (C) and ultrasound combined with microbubbles group (D). Twenty-four hours after treatment, the acid vesicular organelles were detected by acridine orange lfuorescence staining, and transmission electron microscopy (TEM) was used to observe autophagosomes. Results Acridine orange lfuorescence staining showed formation of acid vesicular organelles (AVOs) in the cytoplasm with normal nucleus in both PC3 cells and DU145 cells in group D, while in group A cells were basically normal. Lots of autophagosomes with double-membrane structure were detected by transmission electron microscope in group D. Conclusions Low-frequency and low-intensity ultrasound combined with microbubbles can induced autophagy in both PC3 cells and DU145 cells.
ABSTRACT
Objective To investigate the feasibility of low-frequency ultrasound combined with microbubbles improving transfection of enhanced green lfuorescent protein plasmid (pEGFP) to subcutaneously transplanted prostate cancer in nude mice, and to optimize the parameters of intensity. Methods The model of nude mice of subcutaneously transplanted prostate cancer were built. Then they were divided into 2 groups including low-frequency ultrasound group and low-frequency ultrasound combined with microbubbles group, each group with 15 mice. Then 250μl of mixture of saline and pEGFP (50μg) were co-injected in low-frequency ultrasound group and 250μl of mixture of SonVue and pEGFP (50μg) were co-injected in low-frequency ultrasound combined with microbubbles group through tail vein. According to intensity, they were divided into 3 subgroups respectively, including group 1 W/cm2, group 2 W/cm2 and group 3 W/cm2, each group with 5 mice. Ultrasound was applied at 80 kHz input frequency with 50%duty cycle for 10 minutes after pEGFP injection. The tumors were collected on the third day after treatment. The expression of pEGFP in tumor was examined by laser scanning confocal microscope (ISCM) and the average lfuorescence intensity were estimated. At the same time, routine pathological examination was performed. The mean lfuorescence intensity of low frequency ultrasound group and low frequency ultrasound combined with microbubble group were compared with one-way ANOVA and those of any two groups were compared by SNQ-q test. Results TThe mean lfuorescent light in low-frequency ultrasound combined with microbubbles group were 23.75±2.54, 30.25±1.67 and 59.60±2.03, which were obviously stronger than those of low-frequency ultrasound treatment group (14.04±1.35, 14.66±0.98 and 14.32±1.20), the difference was statistically signiifcant (the value of q were 18.26, 14.12 and 13.88, P<0.05). The rate of gene transfection increased along with the enhancement of the ultrasound intensity (the value of q were 15.33, 17.81 and 13.79, P<0.05). Histology analyses performed by HE staining showed that there was no damage to the tumor tissues in all groups, tumor tissues were intact and without infection. Conclusions Low-frequency ultrasound combination with microbubbles can significantly enhance pEGFP transfecting into subcutaneously transplanted prostate cancer in nude mice. In certain range, improving the ultrasound intensity can increase the rate of gene transfection.
ABSTRACT
Objective To optimize the parameters of the low-frequency/low-energy ultrasound combined with micro-bubbles in inducing early apoptosis of DU145 cells (an androgen-independent prostatic cancer cells). Methods In our study, the impact of ultrasonic power, micro-bubbles/cell suspension volume rate and irradiation time were investigated. Three levels of each factor were deifned as ultrasonic power (60, 80, 100 mW), micro-bubbles/cell suspension volume rate (10%, 20%, 30%), irradiation time (30, 60, 90 s). According to the three-factor three-level orthogonal design, nine experiments were carried out. The early apoptosis was detected by lfow cytometry. A new experiment was designed with the optimized parameters. Another group without ultrasound irradiation was designed as the control group. Flow cytometry and transmission electron microscope (TEM) were used to detect the early apoptosis. Results In descending order, the inlfuence of these factors on the cell early apoptosis were:ultrasonic power>micro-bubbles/cell suspension volume rate>irradiation time. Moreover, the inlfuence of each factor level were:80 mW>60 mW>100 mW in ultrasonic power, 20%>30%>10%in micro-bubbles/cell suspension volume rate, 60 s>90 s >30 s in irradiation time. The early apoptosis rate of experiment group was 10.41%, while the control group was 0.94%. TEM showed apoptotic cells in the experiment group. Conclusions The optimized parameter of low-frequency/low-energy ultrasound with micro-bubbles in inducing early apoptosis of DU145 cells are ultrasonic power of 80 mW, micro-bubbles/cell suspension volume rate of 20%, and irradiation time of 60 s. With the optimized parameters, the early apoptosis rate of the experiment group has signiifcant higher than the control group.