RESUMO
Previous studies demonstrated that variants in dipeptidyl aminopeptidase-like protein-6 (DPP6) are involved in idiopathic ventricular fibrillation. However, its role in early repolarization syndrome (ERS) remains largely elusive. The aim of this study is to determine whether the novel DPP6-L747P variant is associated with ERS, and explore the underlying mechanisms. In our study, whole genome sequencing was used to identify a genetic variant in 4 Chinese families with sudden cardiac arrest induced by ERS. Then, wild-type (WT) DPP6 or mutant (c.2240Tâ¯>â¯C/p.L747P) DPP6 were respectively expressed in HEK293â¯cells, co-expressed with KV4.3 and KChIP2. Western blotting, immunofluorescence, and whole-cell patch clamp experiments were performed to reveal possible underlying mechanisms. A novel missense variant (c.2240Tâ¯>â¯C/p.L747P) in DPP6 was identified in the 4 families. Both DPP6-WT and DPP6-L747P were mainly located on the cell membrane. Compared with DPP6-WT, the intensity of DPP6 protein bands was downregulated in DPP6-L747P. Functional experiments showed that macroscopic currents exhibited an increase in DPP6-L747P, and the current intensity of DPP6-L747P was increased more than that of DPP6-WT (63.1 ± 8.2 pA/pF vs.86.5 ± 15.1 pA/pF at +50 mV, Pâ¯<â¯0.05). Compared with DPP6-WT, the slope of the activation curve of DPP6-L747P was slightly decreased (15.49⯱â¯0.56â¯mV vs. 13.88⯱â¯0.54â¯mV, Pâ¯<â¯0.05), the slope of the inactivation curve was increased (13.65⯱â¯1.57â¯mV, vs. 24.44⯱â¯2.79â¯mV, Pâ¯<â¯0.05) and the recovery time constant was significantly reduced (216.81⯱â¯18.59â¯ms vs. 102.11⯱â¯32.03â¯ms, Pâ¯<â¯0.05). In conclusion, we identified a novel missense variant (c.2240Tâ¯>â¯C/p. L747P) in DPP6 in 4 Chinese families with sudden cardiac arrest induced by ERS. Patch clamp experiments revealed that this variant could generate a gain of function of Ito and affect the potassium current. These results demonstrated that changes caused by the variant may be the underlying mechanisms of malignant arrhythmias in the individuals with ERS.
Assuntos
Arritmias Cardíacas/genética , Povo Asiático/genética , Dipeptidil Peptidases e Tripeptidil Peptidases/genética , Mutação de Sentido Incorreto/genética , Proteínas do Tecido Nervoso/genética , Canais de Potássio/genética , Adolescente , Linhagem Celular , Membrana Celular/genética , Morte Súbita Cardíaca , Regulação para Baixo/genética , Família , Feminino , Células HEK293 , Humanos , MasculinoRESUMO
Previous findings have indicated the potential benefits of the Chinese traditional medicine Qiliqiangxin (QLQX) in heart failure. Here we performed a double-blind, randomized controlled trial to evaluate the efficacy and safety of QLQX in patients with heart failure and reduced ejection fraction (HFrEF). This multicenter trial, conducted in 133 hospitals in China, enrolled 3,110 patients with HFrEF with NT-proBNP levels of ≥450 pg ml-1 and left ventricular ejection fraction of ≤40%. Participants were randomized to receive either QLQX capsules or placebo (four capsules three times daily) alongside standard heart failure therapy. The trial met its primary outcome, which was a composite of hospitalization for heart failure and cardiovascular death: over a median follow-up of 18.3 months, the primary outcome occurred in 389 patients (25.02%) in the QLQX group and 467 patients (30.03%) in the placebo group (hazard ratio (HR), 0.78; 95% confidence interval (CI), 0.68-0.90; P < 0.001). In an analysis of secondary outcomes, the QLQX group showed reductions in both hospitalization for heart failure (15.63% versus 19.16%; HR, 0.76; 95% CI, 0.64-0.90; P = 0.002) and cardiovascular death (13.31% versus 15.95%; HR, 0.83; 95% CI, 0.68-0.996; P = 0.045) compared to the placebo group. All-cause mortality did not differ significantly between the two groups (HR, 0.84; 95% CI, 0.70-1.01; P = 0.058) and adverse events were also comparable between the groups. The results of this trial indicate that QLQX may improve clinical outcomes in patients with HFrEF when added to conventional therapy. ChiCTR registration: ChiCTR1900021929 .
Assuntos
Medicamentos de Ervas Chinesas , Insuficiência Cardíaca , Volume Sistólico , Humanos , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/fisiopatologia , Medicamentos de Ervas Chinesas/uso terapêutico , Medicamentos de Ervas Chinesas/efeitos adversos , Medicamentos de Ervas Chinesas/administração & dosagem , Masculino , Feminino , Método Duplo-Cego , Volume Sistólico/efeitos dos fármacos , Pessoa de Meia-Idade , Idoso , Medicina Tradicional Chinesa , Resultado do Tratamento , Hospitalização , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangueRESUMO
BACKGROUND: Smoking is a well-established risk factor for atherosclerotic disease, but its role as an independent risk factor for venous thromboembolism (VTE) remains controversial. We conducted a meta-analysis to summarize all published prospective studies and case-control studies to update the risk for VTE in smokers and determine whether a dose-response relationship exists. METHODS AND FINDINGS: We performed a literature search using MEDLINE (source PubMed, January 1, 1966 to June 15, 2013) and EMBASE (January 1, 1980 to June 15, 2013) with no restrictions. Pooled effect estimates were obtained by using random-effects meta-analysis. Thirty-two observational studies involving 3,966,184 participants and 35,151 VTE events were identified. Compared with never smokers, the overall combined relative risks (RRs) for developing VTE were 1.17 (95% CI 1.09-1.25) for ever smokers, 1.23 (95% CI 1.14-1.33) for current smokers, and 1.10 (95% CI 1.03-1.17) for former smokers, respectively. The risk increased by 10.2% (95% CI 8.6%-11.8%) for every additional ten cigarettes per day smoked or by 6.1% (95% CI 3.8%-8.5%) for every additional ten pack-years. Analysis of 13 studies adjusted for body mass index (BMI) yielded a relatively higher RR (1.30; 95% CI 1.24-1.37) for current smokers. The population attributable fractions of VTE were 8.7% (95% CI 4.8%-12.3%) for ever smoking, 5.8% (95% CI 3.6%-8.2%) for current smoking, and 2.7% (95% CI 0.8%-4.5%) for former smoking. Smoking was associated with an absolute risk increase of 24.3 (95% CI 15.4-26.7) cases per 100,000 person-years. CONCLUSIONS: Cigarette smoking is associated with a slightly increased risk for VTE. BMI appears to be a confounding factor in the risk estimates. The relationship between VTE and smoking has clinical relevance with respect to individual screening, risk factor modification, and the primary and secondary prevention of VTE. Please see later in the article for the Editors' Summary.
Assuntos
Fumar/efeitos adversos , Tromboembolia Venosa/etiologia , Estudos de Casos e Controles , Estudos de Coortes , Heterogeneidade Genética , Humanos , Incidência , Fatores de Risco , Tromboembolia Venosa/epidemiologiaRESUMO
Normal high-density lipoprotein (nHDL) can induce angiogenesis in healthy individuals. However, HDL from patients with coronary artery disease undergoes various modifications, becomes dysfunctional (dHDL), and loses its ability to promote angiogenesis. Here, we identified a long non-coding RNA, HDRACA, that is involved in the regulation of angiogenesis by HDL. In this study, we showed that nHDL downregulates the expression of HDRACA in endothelial cells by activating WW domain-containing E3 ubiquitin protein ligase 2, which catalyzes the ubiquitination and subsequent degradation of its transcription factor, Kruppel-like factor 5, via sphingosine 1-phosphate (S1P) receptor 1. In contrast, dHDL with lower levels of S1P than nHDL were much less effective in decreasing the expression of HDRACA. HDRACA was able to bind to Ras-interacting protein 1 (RAIN) to hinder the interaction between RAIN and vigilin, which led to an increase in the binding between the vigilin protein and proliferating cell nuclear antigen (PCNA) mRNA, resulting in a decrease in the expression of PCNA and inhibition of angiogenesis. The expression of human HDRACA in a hindlimb ischemia mouse model inhibited the recovery of angiogenesis. Taken together, these findings suggest that HDRACA is involved in the HDL regulation of angiogenesis, which nHDL inhibits the expression of HDRACA to induce angiogenesis, and that dHDL is much less effective in inhibiting HDRACA expression, which provides an explanation for the decreased ability of dHDL to stimulate angiogenesis.
Assuntos
Lipoproteínas HDL , RNA Longo não Codificante , Camundongos , Animais , Humanos , Lipoproteínas HDL/genética , Lipoproteínas HDL/metabolismo , Antígeno Nuclear de Célula em Proliferação , RNA Longo não Codificante/genética , Células Endoteliais/metabolismo , Neovascularização Fisiológica/genéticaRESUMO
BACKGROUND: The optimal salt restriction in patients with heart failure (HF), especially patients with heart failure with preserved ejection fraction (HFpEF), remains controversial. OBJECTIVE: To investigate the associations of cooking salt restriction with risks of clinical outcomes in patients with HFpEF. METHODS: Cox proportional hazards model and subdistribution hazards model were used in this secondary analysis in 1713 participants with HFpEF from the Americas in the TOPCAT trial. Cooking salt score was the sum of self-reported salt added during homemade food preparation. The primary endpoint was a composite of cardiovascular death, HF hospitalisation and aborted cardiac arrest, and secondary outcomes were all-cause death, cardiovascular death and HF hospitalisation. RESULTS: Compared with patients with cooking salt score 0, patients with cooking salt score >0 had significantly lower risks of the primary endpoint (HR=0.760, 95% CI 0.638 to 0.906, p=0.002) and HF hospitalisation (HR=0.737, 95% CI 0.603 to 0.900, p=0.003), but not all-cause (HR=0.838, 95% CI 0.684 to 1.027, p=0.088) or cardiovascular death (HR=0.782, 95% CI 0.598 to 1.020, p=0.071). Sensitivity analyses using propensity score matching baseline characteristics and in patients who prepared meals mostly at home yielded similar results. Subgroup analysis suggested that the association between overstrict salt restriction and poor outcomes was more predominant in patients aged ≤70 years and of non-white race. CONCLUSION: Overstrict cooking salt intake restriction was associated with worse prognosis in patients with HFpEF, and the association seemed to be more predominant in younger and non-white patients. Clinicians should be prudent when giving salt restriction advice to patients with HFpEF.
Assuntos
Insuficiência Cardíaca , Humanos , Prognóstico , Modelos de Riscos Proporcionais , Cloreto de Sódio na Dieta/efeitos adversos , Volume SistólicoRESUMO
1. Metformin is an activator of AMP-activated protein kinase (AMPK). Recent studies suggest that pharmacological activation of AMPK inhibits cardiac hypertrophy. In the present study, we examined whether long-term treatment with metformin could attenuate ventricular hypertrophy in a rat model. The potential involvement of nitric oxide (NO) in the effects of metformin was also investigated. 2. Ventricular hypertrophy was established in rats by transaortic constriction (TAC). Starting 1 week after the TAC procedure, rats were treated with metformin (300 mg/kg per day, p.o.), N(G)-nitro-L-arginine methyl ester (L-NAME; 50 mg/kg per day, p.o.) or both for 8 weeks prior to the assessment of haemodynamic function and cardiac hypertrophy. 3. Cultured cardiomyocytes were used to examine the effects of metformin on the AMPK-endothelial NO synthase (eNOS) pathway. Cells were exposed to angiotensin (Ang) II (10â»6 mol/L) for 24 h under serum-free conditions in the presence or absence of metformin (10⻳ mol/L), compound C (10â»6 mol/L), L-NAME (10â»6 mol/L) or their combination. The rate of incorporation of [³H]-leucine was determined, western blotting analyses of AMPK-eNOS, neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) were undertaken and the concentration of NO in culture media was determined. 4. Transaortic constriction resulted in significant haemodynamic dysfunction and ventricular hypertrophy. Myocardial fibrosis was also evident. Treatment with metformin improved haemodynamic function and significantly attenuated ventricular hypertrophy. Most of the effects of metformin were abolished by concomitant L-NAME treatment. L-NAME on its own had no effect on haemodynamic function and ventricular hypertrophy in TAC rats. 5. In cardiomyocytes, metformin inhibited AngII-induced protein synthesis, an effect that was suppressed by the AMPK inhibitor compound C or the eNOS inhibitor L-NAME. The improvement in cardiac structure and function following metformin treatment was associated with enhanced phosphorylation of AMPK and eNOS and increased NO production. 6. The findings of the present study indicate that long-term treatment with metformin could attenuate ventricular hypertrophy induced by pressure overload via activation of AMPK and a downstream signalling pathway involving eNOS-NO.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Hipertrofia Ventricular Esquerda/prevenção & controle , Metformina/farmacologia , Óxido Nítrico Sintase Tipo III/metabolismo , Animais , Animais Recém-Nascidos , Pressão Sanguínea/efeitos dos fármacos , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Ativação Enzimática/efeitos dos fármacos , Hemodinâmica , Hipertrofia Ventricular Esquerda/metabolismo , Hipertrofia Ventricular Esquerda/patologia , Hipertrofia Ventricular Esquerda/fisiopatologia , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Masculino , Metformina/uso terapêutico , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacosRESUMO
Fractal analysis provides a global assessment of vascular networks (e.g., geometric complexity). We examined the association of diastolic left ventricular (LV) function with the retinal microvascular fractal dimension. A lower fractal dimension signifies a sparser retinal microvascular network. In 628 randomly recruited Flemish individuals (51.3% women; mean age, 50.8 years), we measured diastolic LV function by echocardiography and the retinal microvascular fractal dimension by the box-counting method (Singapore I Vessel Assessment software, version 3.6). The left atrial volume index (LAVI), e', E/e' and retinal microvascular fractal dimension averaged (±SD) 24.3 ± 6.2 mL/m2, 10.9 ± 3.6 cm/s, 6.96 ± 2.2, and 1.39 ± 0.05, respectively. The LAVI, E, e' and E/e' were associated (P < 0.001) with the retinal microvascular fractal dimension with association sizes (per 1 SD), amounting to -1.49 mL/m2 (95% confidence interval, -1.98 to -1.01), 2.57 cm/s (1.31-3.84), 1.34 cm/s (1.07-1.60), and -0.74 (-0.91 to -0.57), respectively. With adjustments applied for potential covariables, the associations of E peak and E/e' with the retinal microvascular fractal dimension remained significant (P ≤ 0.020). Over a median follow-up of 5.3 years, 18 deaths occurred. The crude and adjusted hazard ratios expressing the risk of all-cause mortality associated with a 1-SD increment in the retinal microvascular fractal dimension were 0.36 (0.23-0.57; P < 0.001) and 0.57 (0.34-0.96; P = 0.035), respectively. In the general population, a lower retinal microvascular fractal dimension was associated with greater E/e', a measure of LV filling pressure. These observations can potentially be translated into new strategies for the prevention of diastolic LV dysfunction.
Assuntos
Diástole , Fractais , Retinopatia Hipertensiva , Função Ventricular Esquerda , Bélgica , Diástole/fisiologia , Ecocardiografia , Feminino , Humanos , Retinopatia Hipertensiva/diagnóstico por imagem , Retinopatia Hipertensiva/fisiopatologia , Masculino , Pessoa de Meia-Idade , Função Ventricular Esquerda/fisiologiaRESUMO
AIM: To examine the inhibitory effects of adenosine monophosphate-activated protein kinase (AMPK) activation on cardiac hypertrophy in vitro and to investigate the underlying molecular mechanisms. METHODS: Cultured neonatal rat cardiomyocytes were treated with the specific AMPK activator 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) and the specific AMPK antagonist Compound C, and then stimulated with phenylephrine (PE). The Muscle RING finger 1 (MuRF1)-small interfering RNA (siRNA) was transfected into cardiomyocytes using Lipofectamine 2000. The surface area of cultured cardiomyocytes was measured using planimetry. The protein degradation was determined using high performance liquid chromatography (HPLC). The expression of beta-myosin heavy chain (beta-MHC) and MuRF1, as well as the phosphorylation levels of AMPK and Forkhead box O 1 (FOXO1), were separately measured using Western blot or real-time polymerase chain reaction. RESULTS: Activation of AMPK by AICAR 0.5 mmol/L inhibited PE-induced increase in cardiomyocyte area and beta-MHC protein expression and PE-induced decrease in protein degradation. Furthermore, AMPK activation increased the activity of transcription factor FOXO1 and up-regulated downstream atrogene MuRF1 mRNA and protein expression. Treatment of hypertrophied cardiomyocytes with Compound C 1 micromol/L blunted the effects of AMPK on cardiomyocyte hypertrophy and changes to the FOXO1/MuRF1 pathway. The effects of AICAR on cardiomyocyte hypertrophy were also blocked after MuRF1 was silenced by transfection of cardiomyocytes with MuRF1-siRNA. CONCLUSION: The present study demonstrates that AMPK activation attenuates cardiomyocyte hypertrophy by modulating the atrophy-related FOXO1/MuRF1 signaling pathway in vitro.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Cardiomegalia/enzimologia , Fatores de Transcrição Forkhead/metabolismo , Proteínas Musculares/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Quinases Ativadas por AMP/efeitos dos fármacos , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacologia , Animais , Cardiomegalia/tratamento farmacológico , Células Cultivadas , Ativação Enzimática , Inativação Gênica , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Fenilefrina/farmacologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , RNA Interferente Pequeno/administração & dosagem , Ratos , Ratos Sprague-Dawley , Ribonucleotídeos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Transfecção , Proteínas com Motivo TripartidoRESUMO
The nonpeptide AVE0991 is expected to be a putative new drug for cardiovascular diseases. However, the mechanisms for the cardioprotective actions of AVE0991 are still not fully understood. We planned to determine whether AVE0991 attenuates the angiotensin II (AngII)-induced myocardial hypertrophy and whether these AVE0991 effects involved transforming growth factor beta1 (TGF-beta1) and Smad2. A rat model of neonatal myocardial hypertrophy was induced by AngII. The AngII group significantly increased in protein content, surface area, and [(3)H]leucine incorporation efficiency by cardiomyocytes, compared to those of the control group (P < 0.01). The AngII group also had elevated TGF-beta1 and Smad2 expression (P < 0.01). These AngII-induced changes were significantly attenuated by AVE0991 in a dose-dependent manner. In our study, these actions of AngII (10(-6) mol/l) were significantly inhibited by both concentrations of AVE0991 (10(-5) mol/l and 10(-7) mol/l). Moreover, the high AVE0991 group had significantly better inhibition of myocardial hypertrophy than the low AVE0991 group. Meanwhile, the beneficial effects of AVE0991 were completely abolished when the cardiomyocytes were pretreated with Ang-(1-7) receptor antagonist A-779 (10(-6) mol/l). These results suggested that AVE0991 prevented AngII-inducing myocardial hypertrophy in a dose-dependent fashion, a process that may be associated with the inhibition of TGF-beta1/Smad2 signaling.
Assuntos
Angiotensina II/metabolismo , Cardiomegalia/prevenção & controle , Fármacos Cardiovasculares/farmacologia , Imidazóis/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Proteína Smad2/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Angiotensina II/análogos & derivados , Angiotensina II/farmacologia , Animais , Animais Recém-Nascidos , Cardiomegalia/metabolismo , Cardiomegalia/patologia , Tamanho Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Regulação para Baixo , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Fragmentos de Peptídeos/farmacologia , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína Smad2/genética , Fator de Crescimento Transformador beta1/genéticaRESUMO
1. Rosiglitazone is widely used in the treatment of Type 2 diabetes. However, in recent years it has become evident that the therapeutic effects of peroxisome proliferator-activated receptor gamma ligands reach far beyond their use as insulin sensitizers. Recently, the ability of rosiglitazone pretreatment to induce cardioprotection following ischaemia-reperfusion (I/R) has been well documented; however, the protective mechanisms have not been elucidated. In the present study, examined the role of the phosphatidylinositol 3-kinase (PI3-K)/Akt signalling pathway in rosiglitazone cardioprotection following I/R injury. 2. Mice were pretreated with 3 mg/kg per day rosiglitazone for 14 days before hearts were subjected to ischaemia (30 min) and reperfusion (2 h). Wortmannin (1.4 mg/kg, i.p.), an inhibitor of PI3-K, was administered 10 min prior to myocardial I/R. Then, activation of the PI3-K/Akt/glycogen synthase kinase (GSK)-3alpha signalling pathway was examined. The effects of PI3-K inhibition on rosiglitazone-induced cardioprotection were also evaluated. 3. Compared with control rats, the ratio of infarct size to ischaemic area (area at risk) and the occurrence of sustained ventricular fibrillation in rosiglitazone-pretreated rats was significantly reduced (P < 0.05). Rosiglitazone pretreatment attenuated cardiac apoptosis, as assessed by ELISA to determine cardiomyocyte DNA fragmentation. Rosiglitazone pretreatment significantly increased levels of phosphorylated (p-) Akt and p-GSK-3alpha in the rat myocardium. Pharmacological inhibition of PI3-K by wortmannin markedly abolished the cardioprotection induced by rosiglitazone. 4. These results indicate that rosiglitazone-induced cardioprotection in I/R injury is mediated via a PI3-K/Akt/GSK-3alpha-dependent pathway. The data also suggest that modulation of PI3-K/Akt/GSK-3alpha-dependent signalling pathways may be a viable strategy to reduce myocardial I/R injury.
Assuntos
Traumatismo por Reperfusão Miocárdica/prevenção & controle , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Tiazolidinedionas/uso terapêutico , Androstadienos/farmacologia , Animais , Glicemia/efeitos dos fármacos , Quinase 3 da Glicogênio Sintase/metabolismo , Masculino , Camundongos , Infarto do Miocárdio/enzimologia , Infarto do Miocárdio/prevenção & controle , Traumatismo por Reperfusão Miocárdica/enzimologia , PPAR gama/agonistas , Ratos , Rosiglitazona , Fibrilação Ventricular/enzimologia , Fibrilação Ventricular/prevenção & controle , WortmaninaRESUMO
1. Previously, we showed that long-term treatment of rats after myocardial infarction (MI) with B-type natriuretic peptide (BNP) prevented ventricular remodelling. However, it is unclear whether long-term BNP treatment affects cardiac hypertrophy and, if so, its mechanism of action. In the present study, we investigated the effects of long-term BNP treatment on cardiac hypertrophy and the molecular mechanisms involved. 2. Cardiac hypertrophy was established in rats by ligation of the left anterior descending coronary artery. After treatment with BNP (5 or 15 microg/kg per day) for 8 weeks, indices of cardiac hypertrophy were determined. In separate in vitro experiments, cardiomyocyte hypertrophy was induced by treatment of cardiomyocytes with 10(-6) mol/L angiotensin (Ang) II for 48 h and cell surface area and [(3)H] incorporation were measured. Transforming growth factor (TGF)-beta1 and smad7 mRNA and protein expression in vivo and in vitro were detected using reverse transcription-polymerase chain reaction and western blotting. 3. Long-term BNP treatment dose-dependently attenuated cardiac hypertrophy and improved cardiac function in rats after MI. Furthermore, BNP attenuated the upregulation of TGF-beta1 and downregulation of smad7 mRNA and protein expression. The in vitro experiments further proved that BNP inhibited cardiac hypertrophy and changes in the TGF-beta1/smad7 pathway, which were completely blocked by the cyclic GMP-dependent protein kinase (PKG) inhibitor, KT5823 (cells were treated with 10(-6) mol/L KT5823 for 48 h). 4. The results of the present study demonstrate that long-term treatment of rats with BNP dose-dependently attenuates cardiac hypertrophy and that this is associated with downregulation of TGF-beta1 and upregulation of smad7 via PKG signalling. Long-term BNP treatment may be a new therapeutic strategy to prevent cardiac hypertrophy and progression to heart failure.
Assuntos
Cardiomegalia/metabolismo , Cardiomegalia/prevenção & controle , Peptídeo Natriurético Encefálico/uso terapêutico , Transdução de Sinais/fisiologia , Proteína Smad7/fisiologia , Fator de Crescimento Transformador beta1/fisiologia , Animais , Cardiomegalia/patologia , Células Cultivadas , Relação Dose-Resposta a Droga , Masculino , Peptídeo Natriurético Encefálico/administração & dosagem , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacosRESUMO
Normal high-density lipoprotein (nHDL) in normal, healthy subjects is able to promote angiogenesis, but the mechanism remains incompletely understood. HDL from patients with coronary artery disease may undergo a variety of oxidative modifications, rendering it dysfunctional; whether the angiogenic effect is mitigated by such dysfunctional HDL (dHDL) is unknown. We hypothesized that dHDL compromises angiogenesis. The angiogenic effects of nHDL and dHDL were assessed using endothelial cell culture, endothelial sprouts from cardiac tissue from C57BL/6 mice, zebrafish model for vascular growth and a model of impaired vascular growth in hypercholesterolemic low-density lipoprotein receptor null(LDLr-/-)mice. MiRNA microarray and proteomic analyses were used to determine the mechanisms. Lipid hydroperoxides were greater in dHDL than in nHDL. While nHDL stimulated angiogenesis, dHDL attenuated these responses. Protein and miRNA profiles in endothelial cells differed between nHDL and dHDL treatments. Moreover, nHDL suppressed miR-24-3p expression to increase vinculin expression resulting in nitric oxide (NO) production, whereas dHDL delivered miR-24-3p to inhibit vinculin expression leading to superoxide anion (O2â¢-) generation via scavenger receptor class B type 1. Vinculin was required for endothelial nitric oxide synthase (eNOS) expression and activation and modulated the PI3K/AKT/eNOS and ERK1/2 signaling pathways to regulate nHDL- and VEGF-induced angiogenesis. Vinculin overexpression or miR-24-3p inhibition reversed dHDL-impaired angiogenesis. The expressions of vinculin and eNOS and angiogenesis were decreased, but the expression of miR-24-3p and lipid hydroperoxides in HDL were increased in the ischemic lower limbs of hypercholesterolemic LDLr-/- mice. Overexpression of vinculin or miR-24-3p antagomir restored the impaired-angiogenesis in ischemic hypercholesterolemic LDLr-/- mice. Collectively, nHDL stimulated vinculin and eNOS expression to increase NO production by suppressing miR-24-3p to induce angiogenesis, whereas dHDL inhibited vinculin and eNOS expression to enhance O2â¢- generation by delivering miR-24-3p to impair angiogenesis, and that vinculin and miR-24-3p may be therapeutic targets for dHDL-impaired angiogenesis.
Assuntos
Doença da Artéria Coronariana , MicroRNAs , Animais , Doença da Artéria Coronariana/tratamento farmacológico , Doença da Artéria Coronariana/genética , Células Endoteliais , Voluntários Saudáveis , Humanos , Lipoproteínas HDL , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Neovascularização Fisiológica , Óxido Nítrico Sintase Tipo III/genética , Fosfatidilinositol 3-Quinases , Proteômica , Peixe-ZebraRESUMO
1. It has been demonstrated that epigallocatechin-3-gallate (EGCG) inhibits cardiac hypertrophy through its antihypertensive and anti-oxidant effects. However, the underlying molecular mechanism is not clear. 2. In the present study, we tested the hypothesis that EGCG attenuates transaortic abdominal aortic constriction (TAC)-induced ventricular hypertrophy by regulating mitogen-activated protein kinase (MAPK) signal pathways in hypertensive rats. Four groups of rats were used: (i) a sham-operated control group; (ii) an EGCG-treated (50 mg/kg per day, i.p., for 21 days) sham-operated group; (iii) a TAC group; and (iv) an EGCG-treated TAC group. Histological analysis of whole hearts and biochemical analyses of left ventricular (LV) tissue were used to investigate the effects of EGCG. 3. The results showed that the LV myocyte diameter and the expression of atrial natriuretic peptide, brain natriuretic peptide and ß-myocardial heavy chain were significantly decreased in the EGCG-treated (50 mg/kg per day, i.p.) TAC group. Levels of reactive oxygen species and malondialdehyde in the lV were significantly reduced by EGCG in the TAC group. Total superoxide dismutase, catalase and glutathione peroxidase activities were decreased in the TAC group, and this decrease was significantly restored by EGCG treatment. Phosphorylation of extracellular signal-regulated kinase 2, p38 and c-Jun N-terminal kinase 1 was significantly reversed in the LV of EGCG-treated TAC rats (40%, 53% and 52% vs TAC, respectively), accompanied by significant inhibition of nuclear factor-κB and activator protein-1. Transaortic abdominal aortic constriction significantly upregulated LV expression of matrix metalloproteinase-9 from 32 ± 6 to 100 ± 12% and this increase was inhibited by EGCG treatment (from 100 ± 12 to 50 ± 15%). In addition, TAC decreased mitochondrial DNA copy number and the activity of respiratory chain complexes I (from 100 ± 7 to 68 ± 5%), III (from 100 ± 4 to 2 ± 5%) and IV (from 766 ± 2 to 100 ± 5%); this decrease was reversed by EGCG treatment to levels seen in sham-operated rats.
Assuntos
Antioxidantes/farmacologia , Catequina/análogos & derivados , Hipertensão/tratamento farmacológico , Hipertrofia Ventricular Esquerda/prevenção & controle , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Miocárdio/enzimologia , Animais , Fator Natriurético Atrial/metabolismo , Catalase/metabolismo , Catequina/farmacologia , DNA Mitocondrial/metabolismo , Modelos Animais de Doenças , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , Ativação Enzimática , Glutationa Peroxidase/metabolismo , Hemodinâmica/efeitos dos fármacos , Hipertensão/complicações , Hipertensão/enzimologia , Hipertensão/fisiopatologia , Hipertrofia Ventricular Esquerda/enzimologia , Hipertrofia Ventricular Esquerda/etiologia , Hipertrofia Ventricular Esquerda/patologia , Hipertrofia Ventricular Esquerda/fisiopatologia , Masculino , Malondialdeído/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Mitocôndrias Cardíacas/efeitos dos fármacos , Mitocôndrias Cardíacas/enzimologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 8 Ativada por Mitógeno/metabolismo , Miocárdio/patologia , Cadeias Pesadas de Miosina/metabolismo , NF-kappa B/metabolismo , Peptídeo Natriurético Encefálico/metabolismo , Fosforilação , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Fator de Transcrição AP-1/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
OBJECTIVE: To evaluate the side effects of non-steroidal anti-inflammatory drugs (NSAID) on gastric mucosa, and to study the preventive effects of teprenone in patients. METHODS: 108 patients taking NSAID for more than 3 months with no infection of helicobacter pylori (Hp) were collected. All patients were screened by endoscopy and their upper gastrointestinal symptoms were evaluated. Then, 16 patients with ulcers were excluded and 92 patients were randomly divided into intervention group with teprenone and control group. After follow-up for 3 months, patients were screened again by endoscopy and their upper gastrointestinal symptoms were also evaluated. Specimens of gastric mucosa were studied by PAS dyeing, and Cyclooxygenase (COX) level were evaluated by immunohistochemical technique. RESULTS: Of patients taking NSAIDs, the erosion was found in 48 (44.4%) patients while 16 (14.8%) were found with peptic ulcers. The damages were improved significantly (Z = -4.96, P = 0.000) in the intervention group with teprenone (n = 45) as compared with control group (n = 47) after follow-up for 3 months. Both the cox-1 level [31.1% (14/45) vs 6.7% (3/45), P = 0.003] and mucus thickness [66.7% (30/45) vs 13.3% (6/45), P= 0.000] also increased in the intervention group as compared with control group. No significant difference was found on COX-2 level between these two groups [28.9% (13/45) vs 31.1% (14/45), P = 0.82]. CONCLUSION: Long-term use of NSAID caused severe damages on gastric and duodenal mucosa; teprenone improved NSAID-related gastric side effects and increased the COX-1 level and mucus thickness.
Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Diterpenos/farmacologia , Mucosa Gástrica/efeitos dos fármacos , Adulto , Idoso , Ciclo-Oxigenase 1/metabolismo , Ciclo-Oxigenase 2/metabolismo , Feminino , Seguimentos , Mucosa Gástrica/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto JovemRESUMO
OBJECTIVE: To investigate the expression of liver X receptors (LXR) in hypertrophic myocardium and the effect of LXR agonist T0901317 on angiotensin II (AngII) induced cardiomyocyte hypertrophy. METHODS: Transverse aortic coarctation (TAC) or sham operation were performed in 2-month-old wide type mice (C57/B6). Two weeks later, the expression of LXR in myocardium was detected by quantitative real-time PCR analysis and Western blot analysis. The effect of LXR agonist T0901317 on AngII-induced hypertrophy in cultured neonatal rat cardiomyocytes was also assessed. RESULTS: Quantitative real-time PCR analysis and Western blot analysis showed that LXRalpha but not LXRbeta expression was upregulated post TAC both at mRNA and protein levels (All P < 0.05). AngII induced increased [(3)H] leucine incorporation and cardiomyocyte hypertrophy were significantly reduced by T0901317 in a dose-dependent manner (P < 0.05). T0901317 also dose-dependently inhibited atrial natriuretic peptide (ANP) gene expression in cardiomyocytes (P < 0.05). CONCLUSION: Our findings strongly suggest that LXR is a potent mediator of cardiomyocyte hypertrophy and LXR activation could attenuate AngII induced cardiomyocyte hypertrophy in vitro.
Assuntos
Hidrocarbonetos Fluorados/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Receptores Nucleares Órfãos/agonistas , Sulfonamidas/farmacologia , Angiotensina II/farmacologia , Animais , Animais Selvagens , Células Cultivadas , Receptores X do Fígado , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Receptores Nucleares Órfãos/metabolismoRESUMO
A subgroup analysis of the nationwide, cross-sectional 3B STUDY was performed to understand the current blood pressure (BP) control status and treatment patterns in Chinese diabetes patients as well as to identify factors associated with BP control. The demographic data, anthropometric parameters, and laboratory results were collected from 24 512 type 2 diabetes patients. The BP goal was a systolic BP <130 mm Hg and a diastolic BP <80 mm Hg regardless of a history of hypertension or current antihypertensive treatment. The overall prevalence of hypertension was 59.9% with geographical differences. Among the diabetes patients with hypertension, 76.9% received antihypertensive medicines. Calcium channel blockers (39.3%), angiotensin II receptor antagonists (26.6%), and then ß-blockers (14.0%) or angiotensin-converting enzyme inhibitors (13.6%) were frequently used for BP control. Only 17.5% (n = 2658) of diabetes patients with hypertension reached the recommended target BP. Body mass index <24 kg/m2 , urban resident, frequent physical activity, good adherence to medication, comorbidity with cardiovascular disease, achieving glycemic goal (HbA1c <7.0%), achieving lipid goal (low-density lipoprotein cholesterol <2.59 mmol/L) were independent factors that predicted achievement of target BP goal. On the contrary, comorbidity with chronic kidney disease predicted failure to achieve target BP goal. Patients who were treated in a cardiology department or lived in the North were more likely to achieve BP goals. A considerable proportion of diabetic patients failed to achieve guideline-recommended BP targets. More aggressive efforts should be made to overcome the diverse barriers and facilitate the optimization of diabetes management.
Assuntos
Anti-Hipertensivos , Determinação da Pressão Arterial , Diabetes Mellitus Tipo 2 , Hipertensão , Insuficiência Renal Crônica , Anti-Hipertensivos/classificação , Anti-Hipertensivos/uso terapêutico , Determinação da Pressão Arterial/métodos , Determinação da Pressão Arterial/normas , Índice de Massa Corporal , China/epidemiologia , Estudos Transversais , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/fisiopatologia , Diabetes Mellitus Tipo 2/terapia , Feminino , Hemoglobinas Glicadas/análise , Humanos , Hipertensão/diagnóstico , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Avaliação das Necessidades , Administração dos Cuidados ao Paciente/métodos , Administração dos Cuidados ao Paciente/normas , Planejamento de Assistência ao Paciente/normas , Cooperação do Paciente , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/epidemiologiaRESUMO
OBJECTIVE: To examine the change in nuclear factor-KappaB (NF-KappaB) activity, tumor necrosis factor-alpha (TNF-alpha) and soluble thrombomodulin (sTM) levels at different time following reperfusion in acute myocardial infarction (AMI), and to identify the role of ischemia/reperfusion after ischemia in injury to endothelial cells and its relevant mechanism. METHODS: AMI group included 8 randomly selected patients with AMI, and a normal control group (n=8) composing individuals who underwent health check. NF-KappaB activity in monocytes was determined by electrophoretic mobility shift assays (EMSA). The level of TNF-alpha was measured by radio-immunity and sTM was measured by enzyme linked immunosorbent assay (ELISA). RESULTS: The NF-KappaB activity, TNF-alpha and sTM levels raised dramatically at 0.5 hour after reperfusion, reaching peak at 1 hour and declined gradually at 3, 12 and 24 hours. The levels of all the determined parameters at every time point were significantly higher than that of normal control group, and their levels at 1 hour were significantly higher than that at 24 hours (all P<0.05). There was a positive correlation between the NF-KappaB activity and the levels of TNF-alpha and sTM (all P<0.05). CONCLUSION: These results indicate that NF-KappaB is activated and the levels of TNF-alpha and sTM rise significantly after reperfusion in AMI. The activation of NF-KappaB maybe one of the most important pathogenic mechanism of endothelial injury.
Assuntos
Endotélio Vascular/patologia , Infarto do Miocárdio/fisiopatologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , NF-kappa B/fisiologia , Estudos de Casos e Controles , Humanos , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , NF-kappa B/metabolismo , Terapia Trombolítica , Trombomodulina/sangue , Fator de Necrose Tumoral alfa/sangueRESUMO
OBJECTIVE: To investigate the effects of simvastatin (SIM) on homocysteine (HCY)-induced endothelial dysfunction and inflammatory response. METHODS: Human umbilical vein endothelial cells (HUVECs) were isolated from the umbilical cords from healthy lying-in women and cultured and added with HCY of the concentrations of 0.1, 0.25, 0.5, and 1 mmol/L respectively, or HCY 0.25 mmol/L + SIM of the concentrations of 1, 10 and 20 micromol/L respectively for 1 hour. ELISA was used to detect the cell viability with MTT method. Western blotting was used to examine the protein expression of the cell inflammatory factors, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, macrophage chemoattractant protein (MCP)-1, and intercellular adhesion molecule (ICAM)-1, ELISA was used to detect the contents of the cell inflammatory factors. RESULTS: HCY of different doses inhibited the viability of HUVECs dose-dependently (all P < 0. 01). The survival rates of the HCY-induced HUVECs pretreatment by SIM of the concentrations of 1, 10 and 20 micromol/L for 1 hour were 1.72 +/- 0.03 times, 2.54 +/- 0.09 times, and 3.14 +/- 0.11 times respectively that of the control group (all P < 0. 01). HCY of different concentration of 0.25 mmol/L increased the protein expression of TNF-alpha, IL-6, MCP-1, and ICAM-1 significantly; however, the expression levels of TNF-alpha, IL-6, MCP-1, and ICAM-1 of the 0.25 mmol/L HCY-treated HUVECs that were pretreated by SIM of the concentration of 10 micromol/L for 1 hour were, 0.23 +/- 0.05, 0.14 +/- 0.03, 0.13 +/- 0.04, and 0.21 +/- 0.07 respectively, not significantly different from those at the time of 0 hour (all P > 0.05). CONCLUSION: Simvastatin inhibits the homocysteine-induced endothelial impairment and inflammatory response.
Assuntos
Células Endoteliais/efeitos dos fármacos , Homocisteína/farmacologia , Sinvastatina/farmacologia , Células Cultivadas , Células Endoteliais/metabolismo , Endotélio Vascular/citologia , Feminino , Humanos , Interleucina-6/biossíntese , Interleucina-8/biossíntese , Fator de Necrose Tumoral alfa/biossíntese , Veias Umbilicais/citologia , Molécula 1 de Adesão de Célula Vascular/biossínteseRESUMO
BACKGROUND: Chronic heart failure (CHF) is associated with calcium transients and calcium handling proteins. Angiotensin converting enzyme (ACE) inhibitor has been demonstrated to have beneficial effect on CHF. Yet studies addressed to the relationship between ACE inhibitor and calcium transients in CHF are rare. The aim of this study was to investigate the influence of ACE inhibitor (perindopril) on the contractility and calcium transients and calcium handling proteins in ventricular myocytes from rats with experimental heart failure. METHODS: Male Wistar rats were randomized to heart failure group treated with perindopril [CHF-T, 3 mg.kg(-1).d(-1)], heart failure group without treatment (CHF-C) and sham-operated group (PS). Heart failure was induced by abdominal aortic constriction. All groups were further followed up for 12 weeks. Left ventricular myocytes were then isolated. Single cell shortening fraction and [Ca(2+)]i were simultaneously measured by laser scanning confocal microscope under the field stimulation (1.0 Hz). Reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot were performed to evaluate the changes of mRNA and protein of Na(+)-Ca(2+) exchanger (NCX1), sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2) and phospholamban (PLB). RESULTS: The fraction of cell shortening (FS%) and [Ca(2+)]imax (nmol/L) were significantly reduced in group CHF-C compared with group PS (FS%: 7.51 +/- 1.15 vs 13.21 +/- 1.49; [Ca(2+)]i max: 330.85 +/- 50.05 vs 498.16 +/- 14.07; both P < 0.01), and restored at least partially in CHF-T group. In CHF-C group, the left ventricular mRNA of NCX1 and PLB were significantly upregulated in comparing with PS group (RNCX1/beta-Actin: 0.51 +/- 0.12 vs 0.19 +/- 0.06, P < 0.01; RPLB/beta-Actin: 0.26 +/- 0.12 vs 0.20 +/- 0.08, P < 0.05), while SERCA2 mRNA was downregulated (0.48 +/- 0.10 vs 0.80 +/- 0.11, P < 0.01). The mRNA levels of NCX1 and SERCA2 in CHF-T group were between the CHF-C and PS group, and the differences of the latter two groups were significant (all P < 0.05). In CHF-C and CHF-T groups, the protein expression of NCX1 were 1.141 +/- 0.047 and 1.074 +/- 0.081 times of that in PS group respectively (both P < 0.05), and SERCA2 protein levels were 0.803 +/- 0.100 and 0.893 +/- 0.084 times of that in PS group respectively (both P < 0.05). The protein expression of NCX1 and SERCA2 in the CHF-C and CHF-T groups is significantly different (both P < 0.05). CONCLUSION: ACE inhibitor could improve cardiac function of failing heart through directly enhancing the contractility of single cardiomyocyte, and these effects are probably mediated by its roles in preventing the deleterious changes of calcium transients and calcium handling proteins in CHF.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Cálcio/metabolismo , Insuficiência Cardíaca/tratamento farmacológico , Miócitos Cardíacos/efeitos dos fármacos , Perindopril/farmacologia , Animais , Proteínas de Ligação ao Cálcio/genética , ATPases Transportadoras de Cálcio/genética , Insuficiência Cardíaca/metabolismo , Ventrículos do Coração/efeitos dos fármacos , Masculino , Miócitos Cardíacos/metabolismo , RNA Mensageiro/análise , Ratos , Ratos Wistar , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático , Trocador de Sódio e Cálcio/genéticaRESUMO
OBJECTIVE: To evaluate the effects of Chlamydia pneumoniae infection on oxidative stress and the development of atherosclerosis in C57BL/6J mice. METHODS: Forty-eight C57BL/6J mice were divided into 4 groups including infection of CP and cholesterol diet, cholesterol diet, infection of CP and control. Atherosclerotic lesions were measured in the aortic root at 40 weeks after the primary infection. Production of superoxide was measured by lucigenin-enhanced chemiluminescence response and evaluated in situ with laser scanning confocal microscope. RESULTS: Infected mice fed with an atherogenic diet developed significantly larger lesion areas compared with the single atherogenic diet mice (135 249 +/- 43 748 microm2 vs. 96 378 +/- 30 945 microm2, P < 0.05). Superoxide generation was higher in aortic arches of the infected mice or atherogenic diet mice compared with the control mice (1974.25 +/- 650.49, 701.00 +/- 105.16, 455.62 +/- 77.54 counts.mg(-1).min(-1) vs. 142.25 +/- 31.82 counts.mg(-1).min(-1), respectively, P < 0.001). CONCLUSION: Chlamydia pneumoniae infection accelerates atherosclerotic lesion development in diet-induced hypercholesterolemic mice. Generation of reactive oxygen species may contribute to atherosclerotic development by Chlamydia pneumoniae infection.