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1.
JAMA ; 309(8): 781-91, 2013 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-23443441

RESUMO

IMPORTANCE: Diastolic heart failure (ie, heart failure with preserved ejection fraction) is a common condition without established therapy, and aldosterone stimulation may contribute to its progression. OBJECTIVE: To assess the efficacy and safety of long-term aldosterone receptor blockade in heart failure with preserved ejection fraction. The primary objective was to determine whether spironolactone is superior to placebo in improving diastolic function and maximal exercise capacity in patients with heart failure with preserved ejection fraction. DESIGN AND SETTING: The Aldo-DHF trial, a multicenter, prospective, randomized, double-blind, placebo-controlled trial conducted between March 2007 and April 2012 at 10 sites in Germany and Austria that included 422 ambulatory patients (mean age, 67 [SD, 8] years; 52% female) with chronic New York Heart Association class II or III heart failure, preserved left ventricular ejection fraction of 50% or greater, and evidence of diastolic dysfunction. INTERVENTION: Patients were randomly assigned to receive 25 mg of spironolactone once daily (n=213) or matching placebo (n=209) with 12 months of follow-up. MAIN OUTCOME MEASURES: The equally ranked co-primary end points were changes in diastolic function (E/e') on echocardiography and maximal exercise capacity (peak VO2) on cardiopulmonary exercise testing, both measured at 12 months. RESULTS: Diastolic function (E/e') decreased from 12.7 (SD, 3.6) to 12.1 (SD, 3.7) with spironolactone and increased from 12.8 (SD, 4.4) to 13.6 (SD, 4.3) with placebo (adjusted mean difference, -1.5; 95% CI, -2.0 to -0.9; P < .001). Peak VO2 did not significantly change with spironolactone vs placebo (from 16.3 [SD, 3.6] mL/min/kg to 16.8 [SD, 4.6] mL/min/kg and from 16.4 [SD, 3.5] mL/min/kg to 16.9 [SD, 4.4] mL/min/kg, respectively; adjusted mean difference, +0.1 mL/min/kg; 95% CI, -0.6 to +0.8 mL/min/kg; P = .81). Spironolactone induced reverse remodeling (left ventricular mass index declined; difference, -6 g/m2; 95% CI, -10 to-1 g/m2; P = .009) and improved neuroendocrine activation (N-terminal pro-brain-type natriuretic peptide geometric mean ratio, 0.86; 95% CI, 0.75-0.99; P = .03) but did not improve heart failure symptoms or quality of life and slightly reduced 6-minute walking distance (-15 m; 95% CI, -27 to -2 m; P = .03). Spironolactone also modestly increased serum potassium levels (+0.2 mmol/L; 95% CI, +0.1 to +0.3; P < .001) and decreased estimated glomerular filtration rate (-5 mL/min/1.73 m2; 95% CI, -8 to -3 mL/min/1.73 m2; P < .001) without affecting hospitalizations. CONCLUSIONS AND RELEVANCE: In this randomized controlled trial, long-term aldosterone receptor blockade improved left ventricular diastolic function but did not affect maximal exercise capacity, patient symptoms, or quality of life in patients with heart failure with preserved ejection fraction. Whether the improved left ventricular function observed in the Aldo-DHF trial is of clinical significance requires further investigation in larger populations. TRIAL REGISTRATION: clinicaltrials.gov Identifier: ISRCTN94726526; Eudra-CT No: 2006-002605-31.


Assuntos
Insuficiência Cardíaca Diastólica/tratamento farmacológico , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Espironolactona/uso terapêutico , Função Ventricular Esquerda/efeitos dos fármacos , Idoso , Diástole/fisiologia , Método Duplo-Cego , Ecocardiografia , Teste de Esforço , Feminino , Insuficiência Cardíaca Diastólica/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Qualidade de Vida , Volume Sistólico , Resultado do Tratamento , Remodelação Ventricular
2.
Biochem Pharmacol ; 211: 115504, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36921634

RESUMO

Integrins are a family of cell surface receptors well-recognized for their therapeutic potential in a wide range of diseases. However, the development of integrin targeting medications has been impacted by unexpected downstream effects, reflecting originally unforeseen interference with the bidirectional signalling and cross-communication of integrins. We here selected one of the most severely affected target integrins, the integrin lymphocyte function-associated antigen-1 (LFA-1, αLß2, CD11a/CD18), as a prototypic integrin to systematically assess and overcome these known shortcomings. We employed a two-tiered ligand-based virtual screening approach to identify a novel class of allosteric small molecule inhibitors targeting this integrin's αI domain. The newly discovered chemical scaffold was derivatized, yielding potent bis-and tris-aryl-bicyclic-succinimides which inhibit LFA-1 in vitro at low nanomolar concentrations. The characterisation of these compounds in comparison to earlier LFA-1 targeting modalities established that the allosteric LFA-1 inhibitors (i) are devoid of partial agonism, (ii) selectively bind LFA-1 versus other integrins, (iii) do not trigger internalization of LFA-1 itself or other integrins and (iv) display oral availability. This profile differentiates the new generation of allosteric LFA-1 inhibitors from previous ligand mimetic-based LFA-1 inhibitors and anti-LFA-1 antibodies, and is projected to support novel immune regulatory regimens selectively targeting the integrin LFA-1. The rigorous computational and experimental assessment schedule described here is designed to be adaptable to the preclinical discovery and development of novel allosterically acting compounds targeting integrins other than LFA-1, providing an exemplary approach for the early characterisation of next generation integrin inhibitors.


Assuntos
Antígeno-1 Associado à Função Linfocitária , Transdução de Sinais , Antígeno-1 Associado à Função Linfocitária/química , Antígeno-1 Associado à Função Linfocitária/metabolismo , Ligantes , Molécula 1 de Adesão Intercelular/metabolismo
3.
Eur J Med Res ; 26(1): 107, 2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34530915

RESUMO

BACKGROUND: COVID-19, the pandemic disease caused by infection with SARS-CoV-2, may take highly variable clinical courses, ranging from symptom-free and pauci-symptomatic to fatal disease. The goal of the current study was to assess the association of COVID-19 clinical courses controlled by patients' adaptive immune responses without progression to severe disease with patients' Human Leukocyte Antigen (HLA) genetics, AB0 blood group antigens, and the presence or absence of near-loss-of-function delta 32 deletion mutant of the C-C chemokine receptor type 5 (CCR5). PATIENT AND METHODS: An exploratory observational study including 157 adult COVID-19 convalescent patients was performed with a median follow-up of 250 days. The impact of different HLA genotypes, AB0 blood group antigens, and the CCR5 mutant CD195 were investigated for their role in the clinical course of COVID-19. In addition, this study addressed levels of severity and morbidity of COVID-19. The association of the immunogenetic background parameters were further related to patients' humoral antiviral immune response patterns by longitudinal observation. RESULTS: Univariate HLA analyses identified putatively protective HLA alleles (HLA class II DRB1*01:01 and HLA class I B*35:01, with a trend for DRB1*03:01). They were associated with reduced durations of disease instead decreased (rather than increased) total anti-S IgG levels. They had a higher virus neutralizing capacity compared to non-carriers. Conversely, analyses also identified HLA alleles (HLA class II DQB1*03:02 und HLA class I B*15:01) not associated with such benefit in the patient cohort of this study. Hierarchical testing by Cox regression analyses confirmed the significance of the protective effect of the HLA alleles identified (when assessed in composite) in terms of disease duration, whereas AB0 blood group antigen heterozygosity was found to be significantly associated with disease severity (rather than duration) in our cohort. A suggestive association of a heterozygous CCR5 delta 32 mutation status with prolonged disease duration was implied by univariate analyses but could not be confirmed by hierarchical multivariate testing. CONCLUSION: The current study shows that the presence of HLA class II DRB1*01:01 and HLA class I B*35:01 is of even stronger association with reduced disease duration in mild and moderate COVID-19 than age or any other potential risk factor assessed. Prospective studies in larger patient populations also including novel SARS-CoV-2 variants will be required to assess the impact of HLA genetics on the capacity of mounting protective vaccination responses in the future.


Assuntos
Sistema ABO de Grupos Sanguíneos/genética , COVID-19/etiologia , Antígenos HLA/genética , Receptores CCR5/genética , Adulto , Idoso , COVID-19/epidemiologia , COVID-19/genética , Feminino , Predisposição Genética para Doença , Genótipo , Cadeias HLA-DRB1/genética , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Morbidade , Mutação , Índice de Gravidade de Doença
4.
Eur J Med Res ; 26(1): 87, 2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34362461

RESUMO

BACKGROUND: COVID-19 infection is a major threat to patients and health care providers around the world. One solution is the vaccination against SARS-CoV-2. METHODS: We performed a comprehensive query of the latest publications on the prevention of viral infections including the recent vaccination program and its side effects. RESULTS: The situation is evolving rapidly and there is no reasonable alternative to population-scale vaccination programs as currently enrolled. CONCLUSION: Therefore, regulatory authorities should consider supplementing their conventional mandate of post-approval pharmacovigilance, which is based on the collection, assessment, and regulatory response to emerging safety findings.


Assuntos
Vacinas contra COVID-19/administração & dosagem , COVID-19/prevenção & controle , Consentimento Livre e Esclarecido/normas , Farmacovigilância , SARS-CoV-2/imunologia , Vacinação/normas , COVID-19/imunologia , COVID-19/virologia , Revelação , Humanos
5.
Eur J Med Res ; 26(1): 98, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34433495

RESUMO

BACKGROUND: The coronavirus disease 2019 (COVID-19) is associated with a wide clinical spectrum of skin manifestations, including urticarial, vesicular, vasculitic and chilblain-like lesions. Recently, delayed skin reactions have been reported in 1% individuals following mRNA vaccination against SARS-CoV-2. The exact pathophysiology and the risk factors still remain unclear. PATIENTS AND METHODS: 6821 employees and patients were vaccinated at our institutions between February and June 2021. Every patient received two doses of the mRNA-1273 vaccine in our hospitals, and reported back in case of any side effects which were collected in our hospital managed database. RESULTS: Eleven of 6821 vaccinated patients (0.16%) developed delayed skin reactions after either the first or second dose of the mRNA-1273 vaccine against SARS-CoV-2. Eight of 11 patients (73%) developed a rash after the first dose, while in 3/11 (27%), the rash occurred after the second dose. More females (9/11) were affected. Four of 11 patients required antihistamines, with two needing additional topical steroids. All the cutaneous manifestations resolved within 14 days. None of the skin reactions after the first dose of the vaccine prevented the administration of the second dose. There were no long-term cutaneous sequelae in any of the affected individuals. CONCLUSION: Our data suggests that skin reactions after the use of mRNA-1273 vaccine against SARS-CoV-2 are possible, but rare. Further studies need to be done to understand the pathophysiology of these lesions.


Assuntos
Vacinas contra COVID-19/efeitos adversos , COVID-19/prevenção & controle , Dermatite/etiologia , Eritema/etiologia , Vacina de mRNA-1273 contra 2019-nCoV , Adulto , Idoso , Dermatite/tratamento farmacológico , Dermatite/epidemiologia , Eritema/tratamento farmacológico , Eritema/epidemiologia , Feminino , Antagonistas dos Receptores Histamínicos/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Esteroides/uso terapêutico , Vacinação/efeitos adversos
6.
Br J Pharmacol ; 177(12): 2696-2711, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31985813

RESUMO

BACKGROUND AND PURPOSE: Antibodies targeting cell surface receptors are considered to enable highly selective therapeutic interventions for immune disorders and cancer. Their biological profiles are found, generally, to represent the net effects of antibody-target interactions. The former therapeutic anti-integrin αLß2 antibody efalizumab seems to defeat this paradigm by eliciting, via mechanisms currently unknown, much broader effects than would be predicted based on its target specificity. EXPERIMENTAL APPROACH: To elucidate the mechanisms behind these broad effects, we investigated in primary human lymphocytes in vitro the effects of anti-αLß2 antibodies on the expression of αLß2 as well as unrelated α4 integrins, in comparison to Fab fragments and small-molecule inhibitors. KEY RESULTS: We demonstrate that anti-αLß2 mAbs directly induce the internalization of α4 integrins. The endocytotic phenomenon is a direct consequence of their antibody nature. It is inhibited when monovalent Fab fragments or small-molecule inhibitors are used. It is independent of crosslinking via anti-Fc mAbs and of αLß2 activation. The cross-modulatory effect is unidirectional and not observed in a similar fashion with the α4 integrin antibody natalizumab. CONCLUSION AND IMPLICATIONS: The present study identifies endocytotic cross-modulation as a hitherto unknown non-canonical functionality of anti-αLß2 antibodies. This cross-modulation has the potential to fundamentally alter an antibody's benefit risk profile, as evident with efalizumab. The newly described phenomenon may be of relevance to other therapeutic antibodies targeting cluster-forming receptors. Thus, pharmacologists should be cognizant of this action when investigating such antibodies.


Assuntos
Anticorpos Monoclonais , Antígeno-1 Associado à Função Linfocitária , Anticorpos Monoclonais/farmacologia , Humanos , Fragmentos Fab das Imunoglobulinas , Receptores de Superfície Celular
7.
Eur J Heart Fail ; 10(4): 334-42, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18343721

RESUMO

In human hearts, the transition from cardiac hypertrophy to advanced heart failure (HF) is accompanied by a tremendous increase in Akt phosphorylation. In non-myocardial tissue, the cyclooxygenase (COX)-2 inhibitor celecoxib has been shown to COX-independently inhibit Akt signalling. We studied the effects of celecoxib on Akt signalling and hypertrophic response in myocardium. In rabbit isolated cardiac myocytes celecoxib concentration-dependently (10-100 micromol/L) inhibited the insulin-induced increase in phosphorylation of Akt and its downstream targets, GSK-3beta and p70 S6 kinase, by reducing the phosphorylation level of the upstream regulator PTEN. Inhibition of Akt signalling was accompanied by a significant suppression of characteristic features of cardiac hypertrophy: Celecoxib concentration-dependently suppressed the agonist-induced enhancement of total protein synthesis and BNP mRNA expression. In mice (C57BL/6NCrl) subjected to left ventricular (LV) pressure overload by aortic banding, celecoxib treatment (50mg x kg-1 x d-1) significantly attenuated LV dilation and contractile dysfunction compared with placebo-treated mice. Moreover, celecoxib significantly reduced mortality 8 weeks after banding. Thus, celecoxib can be used to titrate Akt signalling and hypertrophic response in myocardium. It reduces load-induced LV dilation, contractile dysfunction and mortality in vivo. This may have clinical implications for the prevention and treatment of maladaptive hypertrophy and its progression to HF in humans.


Assuntos
Cardiomiopatia Dilatada/fisiopatologia , Cardiomiopatia Hipertrófica/fisiopatologia , Inibidores de Ciclo-Oxigenase/farmacologia , Insuficiência Cardíaca/fisiopatologia , Contração Miocárdica/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Pirazóis/farmacologia , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/farmacologia , Disfunção Ventricular Esquerda/fisiopatologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Cardiomiopatia Dilatada/patologia , Cardiomiopatia Hipertrófica/patologia , Celecoxib , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Feminino , Quinase 3 da Glicogênio Sintase/metabolismo , Insuficiência Cardíaca/patologia , Insulina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Musculares/metabolismo , Contração Miocárdica/fisiologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/fisiologia , Peptídeo Natriurético Encefálico/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Fenilefrina/farmacologia , Fosforilação , Proteínas Proto-Oncogênicas c-akt/fisiologia , Coelhos , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais/fisiologia , Disfunção Ventricular Esquerda/patologia
8.
J Clin Invest ; 111(6): 859-67, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12639992

RESUMO

Cardiac hypertrophy, either compensated or decompensated, is associated with cardiomyocyte contractile dysfunction from depressed sarcoplasmic reticulum (SR) Ca(2+) cycling. Normalization of Ca(2+) cycling by ablation or inhibition of the SR inhibitor phospholamban (PLN) has prevented cardiac failure in experimental dilated cardiomyopathy and is a promising therapeutic approach for human heart failure. However, the potential benefits of restoring SR function on primary cardiac hypertrophy, a common antecedent of human heart failure, are unknown. We therefore tested the efficacy of PLN ablation to correct hypertrophy and contractile dysfunction in two well-characterized and highly relevant genetic mouse models of hypertrophy and cardiac failure, Galphaq overexpression and human familial hypertrophic cardiomyopathy mutant myosin binding protein C (MyBP-C(MUT)) expression. In both models, PLN ablation normalized the characteristically prolonged cardiomyocyte Ca(2+) transients and enhanced unloaded fractional shortening with no change in SR Ca(2+) pump content. However, there was no parallel improvement in in vivo cardiac function or hypertrophy in either model. Likewise, the activation of JNK and calcineurin associated with Galphaq overexpression was not affected. Thus, PLN ablation normalized contractility in isolated myocytes, but failed to rescue the cardiomyopathic phenotype elicited by activation of the Galphaq pathway or MyBP-C mutations.


Assuntos
Proteínas de Ligação ao Cálcio/fisiologia , Cardiomegalia/genética , Insuficiência Cardíaca/prevenção & controle , Contração Miocárdica , Animais , Calcineurina/fisiologia , Cálcio/metabolismo , Proteínas de Transporte/fisiologia , Conexina 43/análise , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP , Proteínas Heterotriméricas de Ligação ao GTP/fisiologia , Camundongos , Camundongos Knockout , Miocárdio/metabolismo , Retículo Sarcoplasmático/metabolismo
9.
Mol Cell Biol ; 22(12): 4124-35, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12024026

RESUMO

Increases in type 1 phosphatase (PP1) activity have been observed in end stage human heart failure, but the role of this enzyme in cardiac function is unknown. To elucidate the functional significance of increased PP1 activity, we generated models with (i) overexpression of the catalytic subunit of PP1 in murine hearts and (ii) ablation of the PP1-specific inhibitor. Overexpression of PP1 (threefold) was associated with depressed cardiac function, dilated cardiomyopathy, and premature mortality, consistent with heart failure. Ablation of the inhibitor was associated with moderate increases in PP1 activity (23%) and impaired beta-adrenergic contractile responses. Extension of these findings to human heart failure indicated that the increased PP1 activity may be partially due to dephosphorylation or inactivation of its inhibitor. Indeed, expression of a constitutively active inhibitor was associated with rescue of beta-adrenergic responsiveness in failing human myocytes. Thus, PP1 is an important regulator of cardiac function, and inhibition of its activity may represent a novel therapeutic target in heart failure.


Assuntos
Proteínas de Transporte , Endorribonucleases , Insuficiência Cardíaca/fisiopatologia , Peptídeos e Proteínas de Sinalização Intracelular , Contração Miocárdica/fisiologia , Fosfoproteínas Fosfatases/metabolismo , Agonistas Adrenérgicos beta/farmacologia , Animais , Cardiomiopatia Dilatada/enzimologia , Cardiomiopatia Dilatada/fisiopatologia , Células Cultivadas , Insuficiência Cardíaca/enzimologia , Humanos , Isoproterenol/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miocárdio/citologia , Miocárdio/metabolismo , Miocárdio/patologia , Fosfoproteínas Fosfatases/efeitos dos fármacos , Fosfoproteínas Fosfatases/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
10.
Eur J Heart Fail ; 8(7): 673-80, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16540370

RESUMO

We investigated the hypothesis that increased intracellular [Na+]i in heart failure contributes to preservation of SR Ca2+ load which may become particularly evident at slow heart rates. [Na+]i in SBFI-loaded myocytes from rabbits with pacing-induced heart failure (PHF) was significantly higher at each frequency as compared to Sham-operated animals. Furthermore, PHF rabbits demonstrated reduced SR Ca2+-ATPase protein levels (-37%, p < 0.04) but unchanged Na+/Ca2+ exchanger protein levels. At 0.25 Hz, isometric force was similar in cardiac trabeculae from PHF rabbits as compared to control (PHF, 3.6+/-1.3; Sham, 4.4+/-0.6 mN/mm2). Rapid cooling contractures (RCCs) were unchanged indicating preserved SR Ca2+ load at this frequency. In Sham, isometric twitch force increased with rising frequencies to 29.0+/-2.8 mN/mm2 at 3.0 Hz (p < 0.05) as compared to 0.25 Hz. RCCs showed a parallel increase by 186+/-47% (p < 0.01). In PHF, frequency-dependent increase in force (15.8+/-4.7 mN/mm2 at 3.0 Hz) and RCCs (increase by 70+/-40%) were significantly blunted. Thus, in PHF in rabbits SR Ca2+ load is preserved at low frequencies despite decreased SR Ca2+-ATPase expression. This may result from [Na+]i-dependent changes in Na+/Ca2+ exchanger activity.


Assuntos
ATPases Transportadoras de Cálcio/metabolismo , Insuficiência Cardíaca/metabolismo , Trocador de Sódio e Cálcio , Sódio/metabolismo , Animais , Modelos Animais de Doenças , Estimulação Elétrica , Células Musculares , Coelhos , Retículo Sarcoplasmático/metabolismo
11.
Circ Res ; 92(7): 769-76, 2003 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-12637367

RESUMO

Phospholamban, the critical regulator of the cardiac SERCA2a Ca2+ affinity, is phosphorylated at Ser16 and Thr17 during beta-adrenergic stimulation (eg, isoproterenol). To assess the impact of nonphosphorylatable phospholamban, a S16A, T17A double-mutant (DM) was introduced into phospholamban knockout mouse hearts. Transgenic lines expressing DM phospholamban at levels similar to wild types (WT) were identified. In vitro phosphorylation confirmed that DM phospholamban could not be phosphorylated, but produced the same shift in EC50 of SERCA2a for Ca2+ as unphosphorylated WT phospholamban. Rates of basal twitch [Ca2+]i decline were not different in DM versus WT cardiomyocytes. Isoproterenol increased the rates of twitch [Ca2+]i decline in WT, but not DM myocytes, confirming the prominent role of phospholamban phosphorylation in this response. Increased L-type Ca2+ current (ICa) density, with unaltered characteristics, was the major compensation in DM myocytes. Consequently, the normal beta-adrenergic-induced increase in ICa caused larger dynamic changes in absolute ICa density. Isoproterenol increased Ca2+ transients to a comparable amplitude in DM and WT. There were no changes in myofilament Ca2+ sensitivity, or the expression levels and Ca2+ removal activities of other Ca2+-handling proteins. Nor was there evidence of cardiac remodeling up to 10 months of age. Thus, chronic inhibition of SERCA2a by ablation of phospholamban phosphorylation (abolishing its adrenergic regulation) results in a unique cellular adaptation involving greater dynamic ICa modulation. This ICa modulation may partly compensate for the loss in SERCA2a responsiveness and thereby partially normalize beta-adrenergic inotropy in DM phospholamban mice.


Assuntos
ATPases Transportadoras de Cálcio/metabolismo , Cálcio/metabolismo , Adaptação Fisiológica/efeitos dos fármacos , Animais , Transporte Biológico/efeitos dos fármacos , Western Blotting , Canais de Cálcio/fisiologia , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , ATPases Transportadoras de Cálcio/genética , Linhagem Celular , Ecocardiografia , Feminino , Ventrículos do Coração/citologia , Ventrículos do Coração/efeitos dos fármacos , Humanos , Isoproterenol/farmacologia , Masculino , Potenciais da Membrana/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos , Camundongos Knockout , Camundongos Transgênicos , Microssomos/metabolismo , Mutação , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/fisiologia , Técnicas de Patch-Clamp , Fosforilação/efeitos dos fármacos , Coelhos , Retículo Sarcoplasmático/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático , Transfecção , Função Ventricular
13.
Cardiovasc Res ; 57(3): 704-14, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12618232

RESUMO

OBJECTIVE: Exogenous catecholamine exposure has been associated with p38 mitogen-activated protein kinase (MAPK) and cardiac hypertrophy. In this study, we investigated the regulation of p38 MAPK in cardiac remodeling elicited by endogenous adrenergic mechanisms. METHODS: Transgenic male and female mice with fourfold phospholamban (PLB) overexpression exhibited enhanced circulating norepinephrine (NE), as a physiological compensatory mechanism to attenuate PLB's inhibitory effects. This enhanced noradrenergic state resulted in left ventricular hypertrophy/dilatation and depressed function. RESULTS: Male transgenics exhibited ventricular hypertrophy and mortality at 15 months, concurrent with cardiac p38 MAPK activation. Female transgenics, despite similar contractile dysfunction, displayed a temporal delay in p38 activation, hypertrophy, and mortality (22 months), which was associated with sustained cardiac levels of MAP Kinase Phosphatase-1 (MKP-1), a potent inhibitor of p38. At 22 months, decreases in cardiac MKP-1 were accompanied by increased levels of p38 activation. In vitro studies indicated that preincubation with 17-beta-estradiol induced high MKP-1 levels, which precluded NE-induced p38 activation. CONCLUSION: These findings suggest that norepinephrine-induced hypertrophy is linked closely with p38 MAP kinase activation, which can be endogenously modulated through estrogen-responsive regulation of MKP-1 expression.


Assuntos
Hipertrofia Ventricular Esquerda/fisiopatologia , Proteínas Quinases Ativadas por Mitógeno/fisiologia , Norepinefrina/fisiologia , Disfunção Ventricular Esquerda/fisiopatologia , Animais , Pressão Sanguínea , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , ATPases Transportadoras de Cálcio/fisiologia , Células Cultivadas , Estradiol/farmacologia , Feminino , Masculino , Camundongos , Camundongos Transgênicos , Células Musculares/efeitos dos fármacos , Células Musculares/enzimologia , Norepinefrina/farmacologia , Fatores Sexuais , Transdução de Sinais , Taxa de Sobrevida , Proteínas Quinases p38 Ativadas por Mitógeno
14.
Cardiovasc Res ; 57(1): 71-81, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12504816

RESUMO

OBJECTIVE: Phospholamban ablation or ectopic expression of SERCA1a in the heart results in significant increases in cardiac contractile parameters. The aim of the present study was to determine whether a combination of these two genetic manipulations may lead to further augmentation of cardiac function. METHODS: Transgenic mice with cardiac specific overexpression of SERCA1a were mated with phospholamban deficient mice to generate a model with SERCA1a overexpression in the phospholamban null background (SERCA1(OE)/PLB(KO)). The cardiac phenotype was characterized using quantitative immunoblotting, sarcoplasmic reticulum calcium uptake and single myocyte mechanics and calcium kinetics. RESULTS: Quantitative immunoblotting revealed an increase of 1.8-fold in total SERCA level, while SERCA2 was decreased to 50% of wild types. Isolated myocytes indicated increases in the maximal rates of contraction by 195 and 125%, the maximal rates of relaxation by 200 and 124%, while the time for 80% decay of the Ca(2+)-transient was decreased to 43 and 75%, in SERCA1(OE)/PLB(KO) hearts, compared to SERCA1a overexpressors and phospholamban knockouts, respectively. These mechanical alterations reflected parallel alterations in V(max) and EC(50) for Ca(2+) of the sarcoplasmic reticulum Ca(2+) transport system. Furthermore, there were no significant cardiac histological or pathological alterations, and the myocyte contractile parameters remained enhanced, up to 12 months of age. CONCLUSIONS: These findings suggest that a combination of SERCA1a overexpression and phospholamban ablation results in further enhancement of myocyte contractility over each individual alteration.


Assuntos
Proteínas de Ligação ao Cálcio/genética , ATPases Transportadoras de Cálcio/genética , Contração Miocárdica , Miocárdio/metabolismo , Animais , Cálcio/metabolismo , ATPases Transportadoras de Cálcio/análise , Tamanho Celular , Deleção de Genes , Expressão Gênica , Immunoblotting , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Retículo Sarcoplasmático/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático
15.
Cardiovasc Res ; 53(2): 372-81, 2002 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11827688

RESUMO

OBJECTIVE: To determine whether the hyperdynamic phospholamban-knockout hearts are capable of withstanding a chronic aortic stenosis. METHODS: The transverse section of the aorta was banded in phospholamban-knockout and their isogenic wild-type mice, which were followed with echocardiography in parallel, along with sham-operated mice, before and at 2.5, 5 and 10 weeks after surgery. RESULTS: Cardiac decompensation was evidenced by the presence of lung congestion in some banded knockouts and wild-types, giving rise to a subset of non-failing and failing hearts within each group. The incidence of heart failure was not genotype-dependent but rather associated with higher heart rates before surgery. The development of left ventricular hypertrophy was similar between knockouts and wild-types and longitudinal assessment of end-diastolic dimension indicated progressive increases after banding, with a greater dilation in failing mice. Fractional shortening was reduced in failing knockouts and wild-types to a similar degree, with an earlier onset in the knockouts. In addition, fractional shortening was decreased in non-failing knockouts but not wild-types. Ejection times shortened after aortic banding particularly for failing hearts. Assessment of the SR Ca(2+)-ATPase protein levels indicated similar downregulation for failing knockouts and wild-types, while the phospholamban levels were not significantly altered in wild-types. CONCLUSION: The hyperdynamic phospholamban-knockout hearts are able to compensate against a sustained aortic stenosis similar to wild-types.


Assuntos
Proteínas de Ligação ao Cálcio/genética , Cardiomegalia/metabolismo , Retículo Sarcoplasmático/metabolismo , Animais , Coartação Aórtica/diagnóstico por imagem , Coartação Aórtica/metabolismo , Coartação Aórtica/fisiopatologia , Proteínas de Ligação ao Cálcio/análise , ATPases Transportadoras de Cálcio/análise , Calsequestrina/análise , Cardiomegalia/diagnóstico por imagem , Cardiomegalia/fisiopatologia , Ecocardiografia , Masculino , Camundongos , Camundongos Knockout , Retículo Sarcoplasmático/química , Fatores de Tempo
16.
Cardiovasc Res ; 56(2): 248-59, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12393095

RESUMO

OBJECTIVE: The role of sarcoplasmic reticulum (SR) in the onset and progression of heart failure is controversial. We tested the hypothesis that impairment of SR Ca2+ sequestration may be a primary cause for progressive left ventricular (LV) dysfunction and the phospholamban hinge domain may be critical in this process. METHODS: A phospholamban hinge domain mutant (PLB/N27A) was introduced in the cardiac compartment of the phospholamban null mouse. An integrative approach was used to characterize the resulting cardiac phenotype at a structural, cellular, whole organ and intact animal level. RESULTS: NMR analysis revealed a defined alteration in the alpha-helical configuration between residues Q22 to F35 in mutant phospholamban. Transgenic lines expressing similar levels of mutant compared to wild-type phospholamban exhibited super-inhibition of the SR Ca2+ ATPase affinity for Ca2+ (EC50 0.52 microM) in oxalate-supported Ca2+ uptake measurements, which translated into impaired relaxation and attenuated responses to beta-adrenergic stimulation. Importantly, a blunted force-frequency relation was observed in mutant hearts preceding left ventricular dilation. Upon aging to 10 months, the predominantly diastolic dysfunction progressed to congestive heart failure, characterized by induction of a fetal gene program, cardiac remodeling, lung congestion, depressed systolic function and early mortality. CONCLUSION: Increased inhibition of Ca2+ sequestration may be a causative factor in the development of left ventricular dysfunction and myocyte remodeling leading to heart failure. Furthermore, the hinge domain may play an important role in transmitting PLB's regulatory effects on SERCA.


Assuntos
Proteínas de Ligação ao Cálcio/fisiologia , Cálcio/metabolismo , Insuficiência Cardíaca/metabolismo , Retículo Sarcoplasmático/metabolismo , Envelhecimento/fisiologia , Animais , Proteínas de Ligação ao Cálcio/química , Proteínas de Ligação ao Cálcio/genética , Progressão da Doença , Insuficiência Cardíaca/patologia , Hemodinâmica , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Mutação , Contração Miocárdica , Estrutura Secundária de Proteína , Relação Estrutura-Atividade , Taxa de Sobrevida , Disfunção Ventricular Esquerda/metabolismo
17.
Eur J Heart Fail ; 17(2): 214-23, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25418979

RESUMO

AIMS: Galectin-3 is a marker of myocardial fibrosis and mediates aldosterone-induced cardiovascular inflammation and fibrosis. Characteristics of galectin-3 and its response to spironolactone have not been evaluated in heart failure with preserved ejection fraction (HFpEF). The aim of this study was to determine the association between galectin-3 levels and patient characteristics in HFpEF; to evaluate the interaction between spironolactone and galectin-3 levels; and to assess the association between galectin-3 and clinical outcomes. METHODS AND RESULTS: Aldo-DHF investigated spironolactone 25 mg once daily vs. placebo for 12 months in patients with NYHA class II-III, LVEF ≥50%, grade ≥ I diastolic dysfunction, and peakVO2 ≤ 25 mL/kg/min. Galectin-3 levels were obtained at baseline, and at 6 and 12 months. The association between baseline galectin-3, change in galectin-3, and all-cause death or hospitalization was evaluated, and the interaction between galectin-3 and treatment was assessed. Median baseline galectin-3 was 12.1 ng/mL. After multivariable adjustment, baseline galectin-3 inversely correlated with peak VO2 (P = 0.021), 6 min walk distance (P = 0.002), and Short Form 36 (SF-36) physical functioning (P = 0.001), and directly correlated with NYHA class (P = 0.007). Baseline NT-proBNP correlated with E/e' velocity ratio (P ≤ 0.001), left atrial volume index (P < 0.001), and LV mass index (P = 0.009). Increasing galectin-3 at 6 or 12 months was associated with all-cause death or hospitalization independent of treatment arm [hazard ratio (HR) 3.319, 95% confidence interval (CI) 1.214-9.07, P = 0.019] and NT-proBNP (HR 3.127, 95% CI 1.144-8.549, P = 0.026). Spironolactone did not influence galectin-3 levels. CONCLUSION: Galectin-3 levels are modestly elevated in patients with stable HFpEF and relate to functional performance and quality of life. Increasing galectin-3 was associated with worse outcome, independent of treatment or NT-proBNP.


Assuntos
Diuréticos/uso terapêutico , Galectina 3/sangue , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/tratamento farmacológico , Espironolactona/uso terapêutico , Volume Sistólico/fisiologia , Idoso , Proteínas Sanguíneas , Feminino , Galectinas , Humanos , Masculino , Pessoa de Meia-Idade , Função Ventricular Esquerda/efeitos dos fármacos , Remodelação Ventricular
18.
J Am Soc Echocardiogr ; 15(10 Pt 1): 1065-73, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12373248

RESUMO

Doppler indices of transmitral flow are commonly used to assess noninvasively left ventricular (LV) diastolic function in species larger than mice. The objective of our study was to characterize patterns of LV diastolic function in 2 genetically altered mouse models using Doppler- and color M-mode echocardiography. Phospholamban (PLB) reversibly inhibits the sarcoplasmic reticulum Ca(2+) ATPase (SERCA) and is a key regulator of myocardial relaxation. Twelve-week-old PLB knockout mice (PLB/KO) were examined in parallel with age-matched transgenic mice expressing a mutant form of PLB (PLB/N27A) that exhibited superinhibition of SERCA. Transmitral Doppler flow indexes, including isovolumic relaxation time, the ratio of peak early-to-late filling velocities, and deceleration time of peak early transmitral velocity indicate impaired diastolic filling in the PLB/N27A mutants, but improved LV diastolic function in the PLB/KO mice. In addition, a relatively load-independent parameter of LV relaxation measured by color M-mode Doppler, the propagation velocity of early flow into the LV cavity confirmed the observed differences. We conclude that transmitral filling patterns and color M-mode flow propagation velocity reflect changes in myocardial relaxation in mice with genetically altered levels of PLB and may be useful tools to characterize LV diastolic function in other mouse models of disease.


Assuntos
Diástole/fisiologia , Hemodinâmica/fisiologia , Função Ventricular Esquerda/fisiologia , Animais , Velocidade do Fluxo Sanguíneo , Proteínas de Ligação ao Cálcio/farmacologia , Ecocardiografia , Ecocardiografia Doppler em Cores , Ventrículos do Coração/diagnóstico por imagem , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Variações Dependentes do Observador , Reprodutibilidade dos Testes
19.
Front Biosci (Elite Ed) ; 5(3): 883-92, 2013 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-23747903

RESUMO

Stretch activates various signal transduction pathways including mitogen-activated protein kinases (MAPK). Stretch-induced phosphorylation of MAPK-contribution to contractility in human myocardium is unknown. We tested the effects of stretch on p44/42-, p38-MAPK and p90rsk phosphorylation and the functional relevance for force development in failing (F) and non-failing (NF) human myocardium. Trabeculae were stretched to a diastolic tension of 12mN/mm2 for 2.5 to 30 minutes and frozen for Western Blot analysis. Stretch induced a time-dependent increase in phosphorylation of p44/42-, p38-MAPK and p90rsk. For functional analysis, trabeculae from F myocardium were stretched and the immediate (Frank-Starling mechanism; FSM) and delayed (slow force response; SFR) increase in twitch force was assessed before and after blocking the activation of p44/42-MAPK (30 micromol/L U0126) and p38-MAPK (10 micromol/L SB203580). Inhibition of p44/42-MAPK almost completely blocked the SFR (106.7 3.7% vs. 125.4 2.9%), while p38-MAPK-blockade significantly increased the SFR (124.6 1.9% vs. 121.2 2.2%). Stretch induced a time-dependent increase in p44/42-, p38-MAPK and p90rsk phosphorylation in F and NF myocardium. While p44/42-MAPK phosphorylation contributed to the SFR, p38-MAPK activation antagonized the stretch-induced SFR.


Assuntos
Proteínas Quinases Ativadas por Mitógeno/metabolismo , Miocárdio/enzimologia , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Estresse Mecânico , Insuficiência Cardíaca/enzimologia , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/patologia , Humanos , Fosforilação
20.
Int J Cardiol ; 169(6): 408-17, 2013 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-24182675

RESUMO

BACKGROUND: To investigate the interaction of clinical characteristics with disease characterising parameters in heart failure with preserved ejection fraction (HFpEF). Methods and results In the multicenter, randomized, placebo-controlled, double-blinded, Aldo-DHF trial investigating the effects of spironolactone on exercise capacity (peakVO2) and diastolic function (E/e') n=422 patients with HFpEF (age 67 ± 8 years, 52% females, LVEF 67 ± 8%) were included. After multiple adjustment, higher age was significantly related to reduced peakVO2, and to increased E/e', NT-proBNP, LAVI as well as LVMI (all p<0.05). Female gender (p<0.001), CAD (p=0.002), BMI (p<0.001), sleep apnoea (p=0.02), and chronotropic incompetence (CI, p=0.002) were related to lower peakVO2 values. Higher pulse pressure (p=0.04), lower heart rates (p=0.03), CI (p=0.03) and beta-blocker treatment (p=0.001) were associated with higher E/e'. BMI correlated inversely (p=0.03), whereas atrial fibrillation (p<0.001), lower haemoglobin levels (p<0.001), CI (p=0.02), and beta-blocker treatment (p<0.001) were associated with higher NT-proBNP. After multiple adjustment for demographic and clinical variables peakVO2 was not significantly associated with E/e' (r=+0.01, p=0.87), logNT-proBNP (r=0.09, p=0.08), LAVI (r=+0.03, p=0.55), and LVMI (r=+0.05, p=0.37). The associations of E/e' with logNT-proBNP (r=0.21, p<0.001), LAVI (r=+0.29, p<0.001) and LVMI (r=0.09, p=0.06) were detectable also after multiple adjustment. CONCLUSIONS: Demographic and clinical characteristics differentially interact with exercise capacity, resting left ventricular filling index, neurohumoral activation, and left atrial and ventricular remodelling in HFpEF. Exercise intolerance in HFpEF is multi-factorial and therapeutic approaches addressing exercise capacity should therefore not only aim to improve single pathological mechanisms. REGISTRATION: ISRCTN94726526 (http://www.controlled-trials.com), Eudra-CT-number 2006-002605-31.


Assuntos
Tolerância ao Exercício/fisiologia , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/fisiopatologia , Espironolactona/uso terapêutico , Volume Sistólico/fisiologia , Idoso , Estudos de Coortes , Método Duplo-Cego , Tolerância ao Exercício/efeitos dos fármacos , Feminino , Insuficiência Cardíaca/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Antagonistas de Receptores de Mineralocorticoides/farmacologia , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Estudos Prospectivos , Espironolactona/farmacologia , Volume Sistólico/efeitos dos fármacos
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