The relationship between uncoupling protein 2 expression and myocardial high energy phosphates content in abdominal aorta constriction induced heart failure rats / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the changes of expression of uncoupling protein 2 (UCP2) in pressure overload induced failure myocardium in rats.</p><p><b>METHODS</b>Male SD rats were randomized into 3 groups (n = 15 each): abdominal aorta constriction (AC) 20 weeks group (H20w group), sham operation group (SH20w group) and normal control group (N group). Twenty weeks later, myocardial function was evaluated by echocardiography and hemodynamic measurements. Mitochondria in ventricular tissue were isolated by centrifugation. Adenine nucleotide pools (ATP, ADP, AMP, PCr) in myocardium were measured by high performance liquid chromatography. The expression of UCP2 in mitochondria was detected by PT-PCR and Western blot analysis.</p><p><b>RESULTS</b>Myocardial function was significantly decreased 20 weeks post-AC compared to SH20w group and N group. Myocardial ATP, ADP, AMP and PCr contents were also significantly decreased in H20w group than the other 2 control groups. The expression of UCP2 in myocardial mitochondria was significantly increased in H20w group and negatively correlated with ATP contents (r = -0.929, P < 0.01).</p><p><b>CONCLUSIONS</b>The expression of UCP2 was upregulated in pressure overload induced failure heart and might be responsible for decreased myocardial adenine nucleotide and energy metabolism disturbance in this model.</p>

Autologous mesenchymal stem cell implantation promotes myocardial expressions of growth factors and improves cardiac function in failing rat hearts / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the underlying mechanism of mesenchymal stem cells (MSCs) transfer induced cardiac function improvement in failing hearts.</p><p><b>METHODS</b>Congestive heart failure (CHF) was induced in rats by cauterization of the heart wall. MSCs were cultured from autologous bone marrow and injected into the border zone and the remote myocardium 5 days after cauterization.</p><p><b>RESULTS</b>Ten weeks later, cardiomyocyte nucleus mitotic index, capillary density and expression of insulin-like growth factor 1 (IGF-1), hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) were significantly increased in the border zone and significantly reduced in the remote myocardium in CHF rats (all P<0.05 vs. sham). Besides cardiac function improvement and left ventricular remodeling attenuation evidenced by hemodynamic and echocardiographic examinations, expressions of IGF-1, HGF and VEGF in the remote myocardium and in the border zone were also significantly upregulated (P<0.05 or P<0.01 vs. CHF), and cardiomyocyte nucleus mitotic index as well as capillary density were significantly increased in CHF rats with MSCs (P<0.05 or P<0.01 vs. CHF). Moreover, collagen area was significantly reduced and myocardial area was significantly increased in the border zone in these rats too.</p><p><b>CONCLUSION</b>Autologous MSC implantation upregulated expressions of growth factors enhanced cardioangiogenesis which might be the underlying mechanisms for improved cardiac function and attenuated left ventricular remodeling induced by MSCs transplantation in failing rat myocardium.</p>

Expressions of beta(3)-adrenoceptor and peroxisome proliferator-activated receptor alpha in human failing heart / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the changes on the content of substrate, the activity of correlative enzyme and the mRNA and protein expressions of beta(3)-adrenoceptor and peroxisome proliferator-activated receptor alpha (PPARalpha) in human failing heart.</p><p><b>METHOD</b>Papillary muscles from 20 patients with heart failure during mitral valves replacement and 6 control subjects died of non-cardiac accidents were obtained and free fat acid (FFA), lactic acid (LD) and the activity of Na(+)K(+)-ATPase and Ca(2+)Mg(2+)-ATPase, protein and mRNA expressions of beta(3)-adrenergic receptor and PPARalpha were measured.</p><p><b>RESULT</b>In the failing heart, the contents of fat acid, LD and expression of beta(3)-adrenoceptor mRNA and protein were significantly higher while the activity of Na(+)K(+)-ATPase and Ca(2+)Mg(2+)-ATPase, expressions of PPARalpha at mRNA and protein levels were significantly lower than those in control myocardium.</p><p><b>CONCLUSION</b>Metabolic remodeling (upregulation of beta(3)-adrenoceptor and downregulation of PPARalpha) might contribute to the pathophysiology of heart failure.</p>

The Effect of Carvedilol on ACE2 Expression in Chronic Heart Failure Rats / 中华高血压杂志

Objective To explore the effect of carvedilol on ACE2 gene and protein expression in chronic heart failure rats after myocardial infarction.Methods The heart failure model was induced by acute myocardial infarc- tion (AMI) through ligating the left anterior descending coronary artery.One month after operation,rats were randomized to receive placebo or carvedilol 2 mg/(kg?d),by gavage.Sham-operated rats were used as the control group.Hemodynamies,body mass and left ventrieular mass index,plasma and myocardial level of angiotensin Ⅱ were determined.ACE2 gene and protein expression was assessed by using RT-PCR and Western Blot.Results The mortality of placebo and Carvedilol groups were 20%,compared with 0% in sham operated rats.Carvedilol significantly improved LVEDP,LVSP,+dp/dt_(max) and-dp/dt_(min) in CHF rats but all the hemodynamics data were still inferior than that of controls.Plasma and myocardial angiotensin Ⅱ level were increased significantly in CHF placebo rats than those of control rats (plasma Ang Ⅱ:CHF:194?19 vs controls:132?15 ng/L,myocardium Ang Ⅱ:CHF:6.7?0.4 vs control:3.8?0.3 ng/g,P

Angiotensin II induced cardiac hypertrophy is blocked by PTEN via suppressing Ca2+/Calcineurin pathway / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the effects of PTEN on Ang II induced cardiomyocyte hypertrophy and subsequent Ca(2+)/Calcineurin pathway changes.</p><p><b>METHODS</b>Primary cultured neonatal rat cardiomyocytes were cultured and were treated with phosphate-buffered saline, empty adenovirus (Ad-GFP), or adenovirus encoding for PTEN (Ad-PTEN-GFP) for 48 h and Ang II (10(-7) mol/L) was added to the medium for another 24 h. Cells were harvested and intracellular Ca(2+) concentration ([Ca(2+)] i) was determined by Fura-2/AM ratio imaging analysis; PTEN, ANF, beta-MHC and CaNAbeta mRNA evaluated with RT-PCR; PTEN and CaNAbeta protein by Western blot; CaN phosphatase activity by CaN detecting kits.</p><p><b>RESULTS</b>PTEN at mRNA and protein levels were significantly higher in Ad-PTEN-GFP treated cardiomyocytes than that of Ad-GFP treated cardiomyocytes. Ang II stimulation upregulated [Ca(2+)] i, CaNAbeta at mRNA and protein levels and CaN phosphatase activity in Ad-GFP treated cardiomyocytes but not in Ad-PTEN-GFP treated cardiomyocytes.</p><p><b>CONCLUSIONS</b>Cardiac hypertrophy induced by Ang II could be blocked by PTEN overexpression via suppressing Ca(2+)/Calcineurin pathway.</p>

Beneficial effects of probucol on endothelial function in patients with acute coronary syndrome / 中华心血管病杂志

<p><b>OBJECTIVE</b>The study investigate the antioxidant probucol on endothelial function in patients with acute coronary syndrome (ACS).</p><p><b>METHODS</b>A total of 49 ACS patients randomly received standard therapy plus probucol (P, n = 24) or standard therapy (C, n = 25). Plasma oxidized low-density lipoprotein (ox-LDL), nitric oxide (NO) and circulating endothelial cells (CEC) were measured. The brachial arterial hyperemia-induced flow mediated dilation (FMD) and sublingual nitroglycerin (NTG) mediated vasodilatations were measured by high resolution ultrasound. These variables were analyzed before and after 3 months therapy.</p><p><b>RESULTS</b>Plasma NO and FMD was significantly increased after 3 months therapy than before therapy [(80.46 +/- 10.24) micromol/Lvs (48.46 +/- 12.24) micromol/L, P < 0.01; (13.46 +/- 1.20)% vs (7.45 +/- 1.02)%, P < 0.05, respectively], while the number of CEC and ox-LDL were significantly decreased (P < 0.01) in P group. These values were similar before and after 3 months in C group. The linear correlation analysis showed that plasma ox-LDL negatively correlated with NO (r = -0.574, P < 0.01) and FMD (r = -0.517, P < 0.01) and positively correlated with CEC (r = 0.385, P < 0.01) in patients received 3 months probucol therapy.</p><p><b>CONCLUSIONS</b>Chronic antioxidant probucol therapy could improve endothelial function in patients with ACS.</p>

The relationship between expressions of beta1-, beta2-, beta3-adrenoceptor mRNA of myocardium and cardiac function in patients with heart failure / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the alteration of expressions of beta(1)-, beta(2)-, beta(3)-adrenoceptor mRNA in human myocardial tissue and the relation between their expressions and cardiac function in patient with heart failure.</p><p><b>METHODS</b>The mRNA expressions of beta(1)-, beta(2)- and beta(3)-adrenergic receptors in myocardial tissue were analyzed by using the reverse transcriptase-polymerase chain reaction in 24 patients with heart failure of valvular heart disease and 5 control subjects.</p><p><b>RESULTS</b>Beta(1)-adrenergic receptor mRNA expressions in myocardium were significantly lower in patients with heart failure than those in control subjects, and progressively reduced with aggravation of heart function. By contrast, beta(3)-adrenoceptor mRNA expressions were significantly higher in patients with heart failure than those in controls, and progressively elevated with aggravation of cardiac function. No difference was observed in beta(2)-adrenergic receptor among all groups.</p><p><b>CONCLUSION</b>The changes of beta-adrenergic receptor mRNA expression are associated with the severity of heart failure.</p>

PTEN negatively regulates isoproterenol-induced cardiac hypertrophy and effects of captopril on PTEN expression / 中华心血管病杂志

<p><b>OBJECTIVE</b>To examine the negative regulation role of PTEN in isoproterenol-induced cardiac hypertrophy by testing the expression of PTEN mRNA and protein and to explore the effects of captopril (Cap) on PTEN expression.</p><p><b>METHODS</b>Twenty four rats were randomly divided into three groups: control group, ISO group, and ISO+Cap group. The following parameters were examined:body weight (BW), heart weight (HW), left ventricular weight (LVW), left ventricular end-diastolic pressure (LVEDP), left ventricular end-systolic pressure (LVESP) and +/- dp/dt(max). The ratio of HW/BW and LVW/BW was calculated. PTEN mRNA and protein were tested by RT-PCR and Western blot, respectively.</p><p><b>RESULTS</b>(1) Compared with the control group, the ratio of HW/BW and LVW/BW, LVEDP and LVESP were all increased in ISO group and ISO+Cap group (P < 0.05), but +/- dp/dt(max) was decreased (P < 0.05); (2) compared with the ISO group, the ratio of HW/BW and LVW/BW, LVEDP, LVESP were all decreased in ISO+Cap group (P < 0.05), but +/- dp/dt(max) was increased (P < 0.05); (3) compared with the control group, PTEN mRNA and protein were up-regulated in ISO group and ISO+Cap group; (4) compared with the ISO group, PTEN mRNA and protein were up-regulated in ISO+Cap group.</p><p><b>CONCLUSIONS</b>PTEN mRNA and protein are up-regulated in isoproterenol-induced cardiac hypertrophy. Captopril can up-regulate PTEN expression in cardiac hypertrophy. There is a negative regulative mechanism in cardiac hypertrophy process, in which PTEN is probably an endogenous negative regulator of cardiac hypertrophy.</p>

Changes of mitochondrial genes expressed in the brain tissue of rat in stroke-like episodes rats / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>Stroke is a complex disorder caused by a combination of genetic and environmental factors. Epidemiological studies have provided evidence of genetic influence on the development of human stroke. However, genetic changes which contribute to the development of stroke are not well known. This study was designed to gain a deep insight into that aspect.</p><p><b>METHODS</b>Using cold-stimuli plus high-salt intake as environmental risk factors, the authors established a hypertension model in rats, which produced a complication of stroke. Then, they used the suppression subtractive hybridization(SSH) technique to identify the differential genes that specifically expressed in total cerebrum tissue of the rats in stroke group. A comparison was made between two populations, namely the control group and stroke group.</p><p><b>RESULTS</b>By the use of SSH approach, a total of 576 clones were generated in this study from two subtractive libraries, among them 456 clones were usable and were analyzed. Genes for metabolism transcripts in stroke group were shown to be up-regulated (P<0.01). Mitochondrial transcripts were observed in a high rate of 26.5%.</p><p><b>CONCLUSION</b>The findings suggested that mitochondrial genes should induce an increased sensitivity to stroke through the changes of gene expressions. Mitochondrial genes probably play important roles in the causes and effects of stroke.</p>

Study on the relationship between nitric oxide synthase gene G894T polymorphism and hypertension related risk factors in patients with essential hypertension in Chongqing city / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the relationship between genetic anomaly and risk factors in hypertension, a polymorphism at position G894T of the gene encoding the endothelial nitric oxide synthase (eNOS) together with hypertension related risk factors were observed in patients with essential hypertension (EH) in Chongqing city.</p><p><b>METHODS</b>Two hundred and twenty-six patients with EH and matched controls were selected. Genotypes of polymorphisms were determined by polymerase chain reaction (PCR), while PCR products were digested by restriction endonuclease (BanII). Questionnaire referred to life style, dietary, smoking, alcohol consumption, psychological and mental state, waist-to-hip ratio (WHR), etc was administered.</p><p><b>RESULTS</b>There was no significant difference noticed in genotype distribution for the eNOS gene G894T genotype between hypertensive groups and controls, but difference was found among certain related risk factors, such as salt intake, snoring and WHR, etc. Logistic regression analysis showed no association between 894T allele and hypertension.</p><p><b>CONCLUSION</b>Although the polymorphism of eNOS gene G894T did not seem to play an important and direct role in the pathogenesis of EH it might have indirect effects through certain risk factors.</p>

Effect of PDGF-AA on Ca2+i in vascular smooth muscle cells in SHRs / 中国应用生理学杂志

<p><b>AIM</b>To explore the relationship between proliferation and hypertrophy of vascular smooth muscle cells and PDGF-AA and PDGFR-alpha expression in SHRs and the role of [Ca2+]i in it.</p><p><b>METHODS</b>Express difference of PDGF-AA, PDGFR-alpha, PDGFR-beta in SHR/WKY-VSMC was observed by Western blot. The effect of Ca2+ inhibitor (nimodipine) on proliferation, hypertrophy and free Ca2+ concentration of SHR-VSMC induced by PDGF-AA was observed by Western blot, [3H] incorporation and fluorescent digital image technique.</p><p><b>RESULTS</b>PDGF-AA and PDGFR-alpha expression was markedly increased in SHR-VSMC than in WKY-VSMC, but PDGFR-beta was not different in SHR and WKY-VSMC. PDGF-AA-stimulated PCNA expression, [3H] incorporation and [Ca2+]i increasing were observed in SHR-VSMC. Dose-dependent nimodipine-inhibited PCNA expression, [3H] incorporation and [Ca2+]i increasing induced by PDGF-AA also were observed in SHR-VSMC.</p><p><b>CONCLUSIONS</b>Spontaneously expression increasing of PDGF-AA and PDGFR-alpha in spontaneously hypertension rats (SHRs) may be one of the important factors on vascular reactivity and vascular modeling mediated through proliferation and hypertrophy in SHR-VSMC, and [Ca2+]i play an important role in this process.</p>

Relationship between proliferation of vascular smooth muscle cells and PDGF-AA and PDGFR-alpha expression in SHRs / 生理学报

To explore the role of platelet derived growth factor-AA (PDGF-AA) and PDGFR-alpha expression in the proliferation and hypertrophy of vascular smooth muscle cells (VSMCs) in spontaneously hypertension rats (SHR), protein expression of PDGF-AA, PDGFR-alpha and PDGFR-beta in SHR/Wistar-Kyoto (WKY)-VSMC was observed by Western blot. Proliferation and hypertrophy of SHR-VSMCs induced by PDGF-AA were observed by measurement of PCNA and [(3)H] incorporation. PDGF-AA and PDGFR-alpha expression was markedly increased in SHR-VSMCs compared with that in WKY-VSMCs, but PDGFR-beta was not different in SHR and WKY-VSMCs. PDGF-AA induced PCNA expression and [(3)H] incorporation was increased in a dose-dependent manner in SHR, but not in WKY. It is suggested that an enhancement of PDGF-AA and PDGFR-alpha in SHRs may be one of the important factors for vascular modeling.

Role of transfected angiotensinⅡ receptor anti-sense nucleotide in the growth of cardiomyocytes / 第三军医大学学报

Objective　To evaluate the role of transfected angiotensinⅡ(Ang Ⅱ) receptor AT1 anti-sense nucleotide (AT1A) in the expression of subtypes of AngⅡ receptor mRNA, synthesis of protein and nucleic acid in cardiomyocytes. Methods　AT1 cDNA sequence (476 bp) was cloned with RT-PCR and reversely inserted into PcDNA3.1 (5.4 kb) to construct an intact plasmid containing AT1A (PAT1A). The plasmid was then transfected into the cultured cardiomyocytes and identified with RT-PCR and Western blot. The synthesis of protein and nucleic acid identified by 3H-Leu and 3H-TdR incorporation, and expressions of AT1 and AT2 mRNA by RT-PCR, were compared between transfected and nontransfected cardiomyocytes after being stimulated with 10-7 mol/L AngⅡ for 24 h. Results　The plasmid PAT1A were successfully constructed. The AT1 mRNA and its protein were expressed significantly less in the transfected cardiomyocytes than in the control (P<0.01). In the transfected cardiomyocytes, AT1 mRNA expression was markedly decreased, but that of AT2 mRNA obviously increased (P<0.01) when compared with the nontransfected cardiomyocytes after stimulation for 24 h with AngⅡ 10-7 mol/L; no significant difference was found in 3H-Leu and 3H-TdR incorporation between them. Conclusion　After the cardiomyocytes was tranfected with AT1A, the expression of AT1 mRNA was markedly suppressed，while AT2 mRNA up-regulated at the same time. Our results indicate that AT1A blocking can not effectively interrupt the Ang Ⅱ-induced synthesis of the protein and nucleic acid in cardiomyocytes.

Effect of vascular endothelial growth factor on apoptosis of endothelial cells induced by hypoxia / 第三军医大学学报

Objective　To explore the effect of hypoxia on the apoptosis of cultured human umbilical vein endothelial cells（HUVECs） and the role of vascular endothelial growth factor（VEGF） in inhibition of apoptosis． Methods　①Culture and identification of HUVECs．②Establishment of hypoxic model（0，12，24，48 h）in HUVECs．③Incubation of HUVECs with VEGF(0 ng, 100 ng) under hypoxic condition for 24 h. ④Detection of apoptosis of HUVECs with TUNEL method． Results　The percentages of apoptosis were different under different hypoxic conditions． The longer hypoxic time was，the higher apoptosis percentage was．VEGF reduced the apoptosis of HUVECs induced by hepoxia． Conclusion　Over-apoptosis EVCs in one of the important factors for the impairment of endothelial function. HEGF inhibits the apoptosis of HVCs and having a pretive function on them.

Role of transfected angiotensinⅡ receptor anti-sense nucleotide in the growth of cardiomyocytes / 第三军医大学学报

Objective　To evaluate the role of transfected angiotensinⅡ(Ang Ⅱ) receptor AT1 anti-sense nucleotide (AT1A) in the expression of subtypes of AngⅡ receptor mRNA, synthesis of protein and nucleic acid in cardiomyocytes. Methods　AT1 cDNA sequence (476 bp) was cloned with RT-PCR and reversely inserted into PcDNA3.1 (5.4 kb) to construct an intact plasmid containing AT1A (PAT1A). The plasmid was then transfected into the cultured cardiomyocytes and identified with RT-PCR and Western blot. The synthesis of protein and nucleic acid identified by 3H-Leu and 3H-TdR incorporation, and expressions of AT1 and AT2 mRNA by RT-PCR, were compared between transfected and nontransfected cardiomyocytes after being stimulated with 10-7 mol/L AngⅡ for 24 h. Results　The plasmid PAT1A were successfully constructed. The AT1 mRNA and its protein were expressed significantly less in the transfected cardiomyocytes than in the control (P<0.01). In the transfected cardiomyocytes, AT1 mRNA expression was markedly decreased, but that of AT2 mRNA obviously increased (P<0.01) when compared with the nontransfected cardiomyocytes after stimulation for 24 h with AngⅡ 10-7 mol/L; no significant difference was found in 3H-Leu and 3H-TdR incorporation between them. Conclusion　After the cardiomyocytes was tranfected with AT1A, the expression of AT1 mRNA was markedly suppressed，while AT2 mRNA up-regulated at the same time. Our results indicate that AT1A blocking can not effectively interrupt the Ang Ⅱ-induced synthesis of the protein and nucleic acid in cardiomyocytes.

Effect of vascular endothelial growth factor on apoptosis of endothelial cells induced by hypoxia / 第三军医大学学报

Objective　To explore the effect of hypoxia on the apoptosis of cultured human umbilical vein endothelial cells（HUVECs） and the role of vascular endothelial growth factor（VEGF） in inhibition of apoptosis． Methods　①Culture and identification of HUVECs．②Establishment of hypoxic model（0，12，24，48 h）in HUVECs．③Incubation of HUVECs with VEGF(0 ng, 100 ng) under hypoxic condition for 24 h. ④Detection of apoptosis of HUVECs with TUNEL method． Results　The percentages of apoptosis were different under different hypoxic conditions． The longer hypoxic time was，the higher apoptosis percentage was．VEGF reduced the apoptosis of HUVECs induced by hepoxia． Conclusion　Over-apoptosis EVCs in one of the important factors for the impairment of endothelial function. HEGF inhibits the apoptosis of HVCs and having a pretive function on them.