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Objective To explore the effects of miRNA-204 targeted LC3B expression on Ang Ⅱ induced cardiomyocytes hypertrophy.Methods The primary neonatal rat cardiomyocytes served as the research objects and divided into the control group,AngⅡ group,combination-treated group 1 (cardiomyocytes were given Ang Ⅱ stimulation,meanwhile infected by negative control lentivirus vector),combination-treated group 2 (cardiomyocytes were given Ang Ⅱ stimulation,meanwhile infected by lentivirus carrying miRNA-204 overexpression vector) according to different treatments.About 48 h to 72 h after intervention treatment,the cardiomyocyte hypertrophy change was detected by confocal microscopy,the expression of miRNA-204 was analyzed by real time PCR,the protein expression of LC3B was measured by Western blot and targeted gene of miRNA-204 was demonstrated by dual-luciferase reporter assay system.Results Compared with the control group,the cardiomyocyte relative surface area in the Ang Ⅱ group was significantly enlarged,the protein expression of LC3B was significantly increased,the expression of miRNA-204 was upregulated,the differences were statistically significant (P＜0.05).Whereas comparing the combination-treated group 1 with combination-treated group 2,the protein expression of LC3B in the latter was down-regulated and the cell area was reduced (P＜0.05).The further luciferase activity report gene experiment results suggested that miRNA-204 was able to bind to LC3B 3'-UTR and decreased the luciferase activities (P＜0.05),but not to bind its mutated fragment for inactivating luciferase activity(P＞0.05).Conclusion miRNA-204 is able to inhibit Ang Ⅱ induced cardiomyocytes hypertrophy,its action is realized by targeting the expression of LC3B.
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Objective To investigate the effects of erythropoietin (EPO) on myocardial apoptosis and protein kinase B (AKT) expression in rats of chronic heart failure (CHF). Methods Thirty male adult SD rats were randomly divided into two groups, sham-operated (Sham) group (n=6) and model (Model) group (n=24). The abdominal aortic coarctation was used to build CHF model. Sixteen survived rats after operation were randomly divided into two groups including EPO group and con-trol (Control) group. EPO group was received 3 000 U/kg EPO intraperitoneal injection 3 times/week for 4 weeks, and Sham group and Control group were received same volume of normal saline. The echocardiography was used to evaluate cardiac function after 4 weeks, 8 weeks and 12 weeks of treatment. After 12 weeks, all rats were sacrificed after 24 h fasting. The cell morphology and myocardial apoptosis were observed, and apoptosis index (AI) was calculated. Myocardial P-AKT/AKT pro-tein expression was detected by Western blot assay. Results Echocardiography showed that ventricular hypertrophy was found in model group after four weeks, heart failure 8 weeks. Compared with Control group, left ventricular ejection fraction (LVEF) was significantly higher after EPO intervention for 4 weeks (P < 0.05), systolic interventricular septum thickness (IVSs), end-systolic left ventricular posterior wall thickness (LVPWs), diastolic interventricular septum thickness (IVSd), af-ter left ventricular end-diastolic wall thickness (LVPWd) were significantly lower (P<0.05). The value of AI was significant-ly lower in EPO group than that of Control group (23.87%±1.45%vs 35.58%±2.81%, P<0.01). The OD value of P-AKT/AKT was significantly decreased in Control group (0.35±0.06) than that of Sham group (0.81±0.17), the value was significant-ly increased in EPO group (1.61±0.16) than that of Control group (P<0.01). Conclusion EPO can improve heart function, inhibit myocardial apoptosis,and promote pro-phosphorylation of AKT in rats with chronic heart failure.
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Objective To explore the effects of miR-34a and the alteration of AMPK/mTOR signal pathway on angiotensin (Ang)Ⅱ-stimulated cardiomyocytes hypertrophy. Methods Neonatal rat cardiomyocytes were cultrued in vitro and were divided into 3 groups:negative control for lentivirus carrying miR-34a group (NC), AngⅡplus lentivirus carrying negative control group (AngⅡ+NC) and AngⅡplus lentivirus carrying miR-34a group (AngⅡ+miR-34a). The relative cell area was detected by confocal microscopy. The expression of miR-34a and hypertrophy-related genes (ANP and β-MHC) were analyzed by real time PCR. The AMPK/mTOR signal pathway was measured by Western blot assay. Results Compared to NC group, the relative cell area was increased in AngⅡ+NC group (P<0.05). But compared with AngⅡ+NC group, the relative cell area was decreased in AngII+miR-34a group (P<0.05). Moreover, compared with NC group, the expression of miR-34a was decreased, and the expression of hyperthophy-related genes(ANP and β-MHC) was up-regulated in AngⅡ+NC group. However, the expression of miR-34a was decreased, and the expression of hyperthophy-related genes (ANP and β-MHC) was down-regulated (P<0.05). Finally, compared to NC group, the ratio of phosphop-AMPK/AMPK was significantly induced in AngII + NC group, but the ratio of phosphop-mTOR/mTOR was significantly decreased (P<0.05). However, compared to AngⅡ+NC group, the ratio of phosphop-AMPK/AMPK was significantly decreased in AngII + miR-34a group, but the ratio of phosphop-mTOR/mTOR was significantly increased (P<0.05). Conclusion miR-34a is able to inhibit myocardial hypertrophy of neonatal rat cardiomyocytes, and its mechanism is partly carried out by the alteration of the signal pathway of AMPK/mTOR.
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Objective To explore the effect and mechanism of renal denervation combined with Losartan on cardiac hypertrophy in spontaneous hypertensive rats. Methods Spontaneous hypertensive rats with cardiac hypertrophy underwent renal denervation combined with following 4 weeks drug treatments. Transthoracic two-dimensional guided M-mode echocardiography was performed. The expression of hypertrophy-related gene was detected. Left ventricularmass index was calculated and histological sectionsstained with hematoxylin and eosin (HE). Results The characteristics of cardiac hypertrophy was observed in left ventricular tissues with HE staining in12 weeks old spontaneous hypertensive rats.The thickness was increased in those ventricular (IVSs, IVSd, LVPWs and LVPWd). After4 weeks after treatment, histological improvements were observed in both RDN and R+L groups compared with sham group. The improvement was more obvious in R+L group. Similar results were observed in histological sections, ventricular thicknesses (IVSs, IVSd, LVPWs and LVPWd), related-hypertrophy genes (ANP and β-MHC) expression, left ventricular mass idex (LVMI) and the protein expression of inflammatory cytokines (TNF-α and IL-6). Conculsion Renal denervation therapy can improve hypertensive-induced cardiac hypertrophy in spontaneous hypertensive rats. The effect was more significant when combined with Losartan. The mechanism might be involved in inhibiting inflammatory cytokines.
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Objective To investigate the distribution of 3279 and 924 Foxp3 genotypes in Guangdong population and to explore the correlation between Foxp3 gene polymorphism and essential hypertention . Methods Two hundred and six essential hypertention patients and 291 healthycontrols from October 2013 to September 2014 in the third affiliated hospital of guangzhou medical university were enrolled in the study. The Foxp3 3279 and 924 genotypes was identified by PCR-SSP assay. The plasma lipid level and other risk factor were detemined in all subjects. The relationship between genotypes and pathogenesis of EH was analyzed. Results There were sigificant differences in frequecncies of allele and genotype distribution in Foxp3 3279 genotypes between the two groups. The frequecies of AC+CC and allele were significantly higher in the EH group than those in the control group (P<0.05). Result of logictics analysis showed that AC+CC genotype significantly increase the risk of EH (OR = 1.552,95%CI为1.021 ~ 2.357, P < 0.05), but the polymorphism of Foxp3 924 genotype frequecncy was not assosiated with EH. Conclusion The Foxp3 3279 gene polymorphisms is associated with EH . However, the Foxp3 924 gene polymorphisms is not associated with EH.