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1.
Clin Sci (Lond) ; 126(7): 497-506, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24168656

RESUMO

miRNAs (microRNAs) have been shown to play a role in myocardial fibrosis. The present study was designed to analyse whether alterations in miRNA expression contribute to the progression of myocardial fibrosis in AS (aortic valve stenosis) patients through up-regulation of the pro-fibrotic factor TGF-ß1 (transforming growth factor-ß type 1). Endomyocardial biopsies were obtained from 28 patients with severe AS, and from the necropsies of 10 control subjects. AS patients presented increased myocardial CVF (collagen volume fraction) and TGF-ß1 compared with the controls, these parameters being correlated in all patients. Patients were divided into two groups by cluster analysis according to their CVF: SF (severe fibrosis; CVF >15%; n=15) and non-SF (CVF ≤15%; n=13). TGF-ß1 was increased in patients with SF compared with those with non-SF. To analyse the involvement of miRNAs in SF, the miRNA expression profile of 10 patients (four with non-SF and six with SF) was analysed showing that 99 miRNAs were down-regulated and 19 up-regulated in the SF patients compared with the non-SF patients. Those miRNAs potentially targeting TGF-ß1 were validated by real-time RT (reverse transcription)-PCR in the whole test population, corroborating that miR-122 and miR-18b were down-regulated in patients with SF compared with those with non-SF and the control subjects. Additionally, miR-122 was inversely correlated with the CVF, TGF-ß1 and the TGF-ß1-regulated PCPE-1 (procollagen C-terminal proteinase enhancer-1) in all patients. Experiments in human fibroblasts demonstrated that miR-122 targets and inhibits TGF-ß1. In conclusion, for the first time we show that myocardial down-regulation of miR-122 might be involved in myocardial fibrosis in AS patients, probably through TGF-ß1 up-regulation.


Assuntos
Estenose da Valva Aórtica/fisiopatologia , Regulação para Baixo , Fibrose/fisiopatologia , MicroRNAs/fisiologia , Fator de Crescimento Transformador beta1/fisiologia , Regulação para Cima , Idoso , Feminino , Humanos , Hibridização In Situ , Masculino
2.
Arterioscler Thromb Vasc Biol ; 33(4): e104-12, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23393389

RESUMO

OBJECTIVE: Reactive oxygen species-generating nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase proteins (Noxs) are involved in cell differentiation, migration, and apoptosis. Nox4 is unique among Noxs in being constitutively active, and its subcellular localization may therefore be particularly important. In this study, we identified and characterized a novel nuclear-localized 28-kDa splice variant of Nox4 in vascular cells. APPROACH AND RESULTS: Nox4 immunoreactivity was noted in the nucleus and nucleolus of vascular smooth muscle cells and multiple other cell types by confocal microscopy. Cell fractionation, sequence analyses, and siRNA studies indicated that the nuclear-localized Nox4 is a 28-kDa splice variant, Nox4D, which lacks putative transmembrane domains. Nox4D overexpression resulted in significant NADPH-dependent reactive oxygen species production as detected by several different methods and caused increased phosphorylation of extracellular-signal-regulated kinase1/2 and the nuclear transcription factor Elk-1. Overexpression of Nox4D could also induce DNA damage as assessed by γ-H2AX phosphorylation. These effects were inhibited by a single amino acid substitution in the Nox4D NADPH-binding region. CONCLUSIONS: Nox4D is a nuclear-localized and functionally active splice variant of Nox4 that may have important pathophysiologic effects through modulation of nuclear signaling and DNA damage.


Assuntos
Núcleo Celular/enzimologia , Fibroblastos/enzimologia , Células Endoteliais da Veia Umbilical Humana/enzimologia , Músculo Liso Vascular/enzimologia , Miócitos Cardíacos/enzimologia , Miócitos de Músculo Liso/enzimologia , NADPH Oxidases/metabolismo , Animais , Dano ao DNA , Ativação Enzimática , Imunofluorescência , Células HEK293 , Histonas/metabolismo , Humanos , Microscopia Confocal , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Peso Molecular , Mutagênese Sítio-Dirigida , NADPH Oxidase 4 , NADPH Oxidases/genética , Oxirredução , Fosforilação , Cultura Primária de Células , Isoformas de Proteínas , Interferência de RNA , Ratos , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Transfecção
3.
Hypertension ; 81(2): 218-228, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38084597

RESUMO

Hypertensive heart disease (HHD) can no longer be considered as the beneficial adaptive result of the hypertrophy of cardiomyocytes in response to pressure overload leading to the development of left ventricular hypertrophy. The current evidence indicates that in patients with HHD, pathological lesions in the myocardium lead to maladaptive structural remodeling and subsequent alterations in cardiac function, electrical activity, and perfusion, all contributing to poor outcomes. Diffuse myocardial interstitial fibrosis is probably the most critically involved lesion in these disorders. Therefore, in this review, we will focus on the histological characteristics, the mechanisms, and the clinical consequences of myocardial interstitial fibrosis in patients with HHD. In addition, we will consider the most useful tools for the noninvasive diagnosis of myocardial interstitial fibrosis in patients with HHD, as well as the most effective available therapeutic strategies to prevent its development or facilitate its regression in this patient population. Finally, we will issue a call to action for the need for more fundamental and clinical research on myocardial interstitial fibrosis in HHD.


Assuntos
Cardiomiopatias , Cardiopatias , Hipertensão , Humanos , Cardiopatias/patologia , Miocárdio/patologia , Hipertrofia Ventricular Esquerda , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Hipertensão/patologia , Fibrose
4.
Heart ; 110(19): 1157-1163, 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39117384

RESUMO

Myocardial remodelling, entailing cellular and molecular changes in the different components of the cardiac tissue in response to damage, underlies the morphological and structural changes leading to cardiac remodelling, which in turn contributes to cardiac dysfunction and disease progression. Since cardiac tissue is not available for histomolecular diagnosis, surrogate markers are needed for evaluating myocardial remodelling as part of the clinical management of patients with cardiac disease. In this setting, circulating biomarkers, a component of the liquid biopsy, provide a promising approach for the fast, affordable and scalable screening of large numbers of patients, allowing the detection of different pathological features related to myocardial remodelling, aiding in risk stratification and therapy monitoring. However, despite the advances in the field and the identification of numerous potential candidates, their implementation in clinical practice beyond natriuretic peptides and troponins is mostly lacking. In this review, we will discuss some biomarkers related to alterations in the main cardiac tissue compartments (cardiomyocytes, extracellular matrix, endothelium and immune cells) which have shown potential for the assessment of cardiovascular risk, cardiac remodelling and therapy effects. The hurdles and challenges for their translation into clinical practice will also be addressed.


Assuntos
Biomarcadores , Remodelação Ventricular , Humanos , Biomarcadores/sangue , Remodelação Ventricular/fisiologia , Miocárdio/patologia , Miocárdio/metabolismo , Cardiopatias/sangue , Cardiopatias/diagnóstico , Cardiopatias/terapia , Cardiopatias/fisiopatologia
5.
Clin Sci (Lond) ; 125(6): 291-300, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23550626

RESUMO

The NADPH oxidases are a key family of ROS (reactive oxygen species)-producing enzymes which may differentially contribute to cardiac pathophysiology. Animal studies show uncertain results regarding the regulation of cardiac Nox4 by pressure overload and no data are available on human myocardial Nox4. In the present study, we evaluated Nox4 expression and its relationship with myocardial remodelling and LV (left ventricular) function in patients with severe AS (aortic valve stenosis). Endomyocardial biopsies from 34 patients with AS were obtained during aortic valve replacement surgery. LV morphology and function were assessed by echocardiography. Myocardial samples from subjects deceased of non-CVDs (cardiovascular diseases) were analysed as controls. Nox4 localization was evaluated by immunohistochemistry and quantified by Western blot. Myocardial capillary density, fibrosis and cardiomyocyte dimensions and apoptosis were assessed histologically to evaluate myocardial remodelling. Nox4 was present in samples from all subjects and expressed in cardiomyocytes, VSMCs (vascular smooth muscle cells), endothelium and fibroblasts. Nox4 levels were reduced 5-fold in AS patients compared with controls (P<0.01). Nox4 levels directly correlated with cardiomyocyte cross-sectional area (r=0.299, P<0.05) and diameter (r=0.406, P<0.05) and capillary density (r=0.389, P<0.05), and inversely with cardiomyocyte apoptosis (r=-0.316, P<0.05) in AS patients. In addition, Nox4 levels correlated with echocardiographic parameters (LV ejection fraction: r=0.353, P<0.05; midwall fractional shortening: r=0.355, P<0.05; deceleration time: r=-0.345, P<0.05) in AS patients. Nox4 is expressed in human myocardium and reduced in AS patients. The observed associations of Nox4 with cardiomyocyte parameters and capillary density in AS patients suggest a potential role of Nox4 deficiency in the myocardial remodelling present in the human pressure-overloaded heart.


Assuntos
Estenose da Valva Aórtica/enzimologia , Miocárdio/enzimologia , NADPH Oxidases/análise , Adulto , Idoso , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/fisiopatologia , Apoptose , Biópsia , Western Blotting , Capilares/patologia , Regulação para Baixo , Ecocardiografia Doppler de Pulso , Feminino , Fibrose , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Miocárdio/patologia , NADPH Oxidase 4 , Proteínas Nucleares/análise , Índice de Gravidade de Doença , Volume Sistólico , Função Ventricular Esquerda , Remodelação Ventricular
6.
Mol Aspects Med ; 93: 101194, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37384998

RESUMO

Heart failure is a leading cause of mortality and hospitalization worldwide. Cardiac fibrosis, resulting from the excessive deposition of collagen fibers, is a common feature across the spectrum of conditions converging in heart failure. Eventually, either reparative or reactive in nature, in the long-term cardiac fibrosis contributes to heart failure development and progression and is associated with poor clinical outcomes. Despite this, specific cardiac antifibrotic therapies are lacking, making cardiac fibrosis an urgent unmet medical need. In this context, a better patient phenotyping is needed to characterize the heterogenous features of cardiac fibrosis to advance toward its personalized management. In this review, we will describe the different phenotypes associated with cardiac fibrosis in heart failure and we will focus on the potential usefulness of imaging techniques and circulating biomarkers for the non-invasive characterization and phenotyping of this condition and for tracking its clinical impact. We will also recapitulate the cardiac antifibrotic effects of existing heart failure and non-heart failure drugs and we will discuss potential strategies under preclinical development targeting the activation of cardiac fibroblasts at different levels, as well as targeting additional extracardiac processes.


Assuntos
Insuficiência Cardíaca , Miocárdio , Humanos , Miocárdio/patologia , Fibroblastos , Biomarcadores , Fibrose
7.
JACC Heart Fail ; 11(1): 58-72, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36599551

RESUMO

BACKGROUND: Myocardial fibrosis may increase vulnerability to poor prognosis in patients with heart failure (HF), even in those patients exhibiting left ventricular reverse remodeling (LVRR) after guideline-based therapies. OBJECTIVES: This study sought to characterize fibrosis at baseline in patients with HF with left ventricular ejection fraction (LVEF) <50% by determining serum collagen type I-derived peptides (procollagen type I C-terminal propeptide [PICP] and ratio of collagen type I C-terminal telopeptide to matrix metalloproteinase-1) and to evaluate their association with LVRR and prognosis. METHODS: Peptides were determined in 1,034 patients with HF at baseline. One-year echocardiography was available in 665 patients. Associations of peptides with 1-year changes in echocardiographic variables were analyzed by multivariable linear mixed models. LVEF was considered improved if it increased by ≥15% or to ≥50% or if it increased by ≥10% to >40% in patients with LVEF ≤40%. Cardiovascular death and HF-related outcomes were analyzed in all patients randomized to derivation (n = 648) and validation (n = 386) cohorts. RESULTS: Continuous associations with echocardiographic changes were observed only for PICP. Compared with high-PICP (≥108.1 ng/mL) patients, low-PICP (<108.1 ng/mL) patients exhibited enhanced LVRR and a lower risk of HF-related outcomes (P ≤ 0.018), with women and nonischemic patients with HF showing a stronger LVEF increase (interaction P ≤ 0.010). LVEF increase was associated with a better prognosis, particularly in low-PICP patients (interaction P ≤ 0.029). Only patients with both low PICP and improved LVEF exhibited a better clinical evolution than patients with nonimproved LVEF (P < 0.001). CONCLUSIONS: Phenotyping with PICP, a peptide associated with myocardial fibrosis, may be useful to differentiate patients with HF who are more likely to experience clinical myocardial recovery from those with partial myocardial improvement.


Assuntos
Cardiomiopatias , Insuficiência Cardíaca , Humanos , Feminino , Colágeno Tipo I , Volume Sistólico , Função Ventricular Esquerda , Fragmentos de Peptídeos , Pró-Colágeno , Biomarcadores , Colágeno , Peptídeos , Fibrose
8.
Biochim Biophys Acta Mol Cell Res ; 1867(3): 118521, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31394074

RESUMO

Myocardial interstitial fibrosis (MIF) is a common finding in heart failure (HF) patients, both with preserved and reduced ejection fraction, as well as in HF animal models. MIF is associated with impaired cardiac function and worse clinical outcome. The impact of MIF is influenced not only by the quantity but also by changes in the quality of collagen fibers and in the extracellular matrix components, such as a shift in collagen types proportion, increased fibronectin polymerization and increased degree of collagen cross-linking (CCL). In particular, CCL, a process that renders collagen fibers stiffer and more resistant to degradation, is increased both in patients and animal models of HF. Importantly, in HF patients increased cardiac CCL is directly associated with increased left ventricular stiffness and a higher risk of hospitalization for HF. The aim of this review is to address the complexity of MIF in HF, focusing on CCL.

10.
Nefrologia (Engl Ed) ; 40(3): 223-236, 2020.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31901373

RESUMO

Patients with the dual burden of chronic kidney disease (CKD) and chronic congestive heart failure (HF) experience unacceptably high rates of symptom load, hospitalization, and mortality. Currently, concerted efforts to identify, prevent and treat HF in CKD patients are lacking at the institutional level, with emphasis still being placed on individual specialty views on this topic. The authors of this review paper endorse the need for a dedicated cardiorenal interdisciplinary team that includes nephrologists and renal nurses and jointly manages appropriate clinical interventions across the inpatient and outpatient settings. There is a critical need for guidelines and best clinical practice models from major cardiology and nephrology professional societies, as well as for research funding in both specialties to focus on the needs of future therapies for HF in CKD patients. The implementation of cross-specialty educational programs across all levels in cardiology and nephrology will help train future specialists and nurses who have the ability to diagnose, treat, and prevent HF in CKD patients in a precise, clinically effective, and cost-favorable manner.


Assuntos
Necessidades e Demandas de Serviços de Saúde , Insuficiência Cardíaca/epidemiologia , Insuficiência Renal Crônica/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Instituições de Assistência Ambulatorial/organização & administração , Biomarcadores , Cardiologia/educação , Fármacos Cardiovasculares/uso terapêutico , Terapia Combinada , Comorbidade , Currículo , Gerenciamento Clínico , Progressão da Doença , Diuréticos/uso terapêutico , Educação Médica , Educação em Enfermagem , Everolimo/efeitos adversos , Everolimo/uso terapêutico , Cardiopatias/diagnóstico , Cardiopatias/diagnóstico por imagem , Insuficiência Cardíaca/economia , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Humanos , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Incidência , Guias de Prática Clínica como Assunto , Prevalência , Prognóstico , Insuficiência Renal Crônica/economia , Insuficiência Renal Crônica/fisiopatologia , Insuficiência Renal Crônica/terapia , Terapia de Substituição Renal/efeitos adversos , Terapia de Substituição Renal/métodos , Pesquisa , Autocuidado
11.
Clin Sci (Lond) ; 116(3): 233-40, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18647135

RESUMO

The objective of the present study was to analyse the influence of the ACE (angiotensin-converting enzyme) gene I/D (insertion/deletion) polymorphism on NADPH oxidase-dependent O(2)(*-) (superoxide radical) production, and to investigate the clinical implication of this association in hypertensive subjects. A case-control study was performed in a random sample of the general population composed of 189 normotensive subjects and 223 hypertensive subjects. The ACE polymorphism was determined by PCR. NADPH oxidase-dependent O(2)(*-) production was quantified in phagocytic cells by chemiluminescence. MMP-9 (matrix metalloproteinase-9), a marker of atherosclerosis previously reported to be associated with NADPH oxidase overactivity, was quantified by ELISA in plasma samples. The distribution of genotypes was in Hardy-Weinberg equilibrium. The I/D polymorphism was not associated with hypertension. NADPH oxidase-dependent O(2)(*-) production was significantly higher in D/D (deletion/deletion) than in I/I (insertion/insertion) and I/D, both in normotensive and hypertensive subjects. Interestingly, plasma levels of angiotensin II were significantly higher in D/D than in I/I and I/D, both in normotensive and hypertensive subjects. Plasma levels of MMP-9 and systolic blood pressure values were significantly higher in D/D than in I/I and I/D hypertensive subjects, whereas no differences were found among genotypes in normotensive subjects. Interestingly, NADPH oxidase-dependent O(2)(*-) production positively associated with plasma MMP-9 levels in hypertensive subjects, which remained significant after adjustment for age and gender. In conclusion, in the present study we have reported for the first time an association of the D/D genotype of the ACE I/D polymorphism with phagocytic NADPH oxidase-mediated O(2)(*-) overproduction. Within the group of hypertensive patients, D/D cases also associated with increased blood pressure values and with enhanced plasma levels of MMP-9.


Assuntos
Hipertensão/genética , NADPH Oxidases/fisiologia , Peptidil Dipeptidase A/genética , Superóxidos/metabolismo , Estudos de Casos e Controles , Feminino , Deleção de Genes , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Hipertensão/enzimologia , Hipertensão/metabolismo , Lipídeos/sangue , Masculino , Metaloproteinase 9 da Matriz/sangue , Pessoa de Meia-Idade , Mutagênese Insercional , NADPH Oxidases/metabolismo , Fagócitos/metabolismo , Polimorfismo Genético
12.
Biochim Biophys Acta Mol Cell Res ; 1866(9): 1421-1432, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31181222

RESUMO

Myocardial interstitial fibrosis (MIF) is a common finding in heart failure (HF) patients, both with preserved and reduced ejection fraction, as well as in HF animal models. MIF is associated with impaired cardiac function and worse clinical outcome. The impact of MIF is influenced not only by the quantity but also by changes in the quality of collagen fibers and in the extracellular matrix components, such as a shift in collagen types proportion, increased fibronectin polymerization and increased degree of collagen cross-linking (CCL). In particular, CCL, a process that renders collagen fibers stiffer and more resistant to degradation, is increased both in patients and animal models of HF. Importantly, in HF patients increased cardiac CCL is directly associated with increased left ventricular stiffness and a higher risk of hospitalization for HF. The aim of this review is to address the complexity of MIF in HF, focusing on CCL.


Assuntos
Colágeno/metabolismo , Matriz Extracelular/metabolismo , Fibrose/metabolismo , Insuficiência Cardíaca/metabolismo , Miocárdio/metabolismo , Animais , Colágeno/uso terapêutico , Modelos Animais de Doenças , Ventrículos do Coração/metabolismo , Humanos , Proteína-Lisina 6-Oxidase/metabolismo
13.
Clin Sci (Lond) ; 114(3): 173-82, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18184111

RESUMO

Oxidative stress plays a key role in the pathophysiology of several major cardiovascular diseases, including atherosclerosis, hypertension, heart failure, stroke and diabetes. ROS (reactive oxygen species) affect multiple tissues either directly or through NO depletion. ROS induce cardiovascular dysfunction by modulating cell contraction/dilation, migration, growth/apoptosis and extracellular matrix protein turnover, which contribute to vascular and cardiac remodelling. Of the several sources of ROS within the cardiovascular system, a family of multisubunit NADPH oxidases appears to be a predominant contributor of superoxide anion. Recent findings suggest a significant role of the genetic background in NADPH oxidase regulation. Common genetic polymorphisms within the promoter and exonic sequences of CYBA, the gene that encodes the p22(phox) subunit of NADPH oxidase, have been characterized in the context of cardiovascular diseases. This review aims to present the current state of research into these polymorphisms in their relationship to cardiovascular diseases.


Assuntos
Doenças Cardiovasculares/genética , NADPH Oxidases/genética , Estresse Oxidativo/genética , Polimorfismo Genético , Doenças Cardiovasculares/enzimologia , Doenças Cardiovasculares/fisiopatologia , Humanos , NADPH Oxidases/fisiologia
14.
Arterioscler Thromb Vasc Biol ; 27(3): 587-93, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17194891

RESUMO

OBJECTIVE: Data suggest that matrix metalloproteinase-9 (MMP-9) has a role in atherosclerosis. The phagocytic NADPH oxidase has been also associated with atherosclerosis. This study aimed to investigate the association between phagocytic NADPH oxidase and MMP-9 in human atherosclerosis. METHODS AND RESULTS: In vitro experiments performed in human monocytes showed that NADPH oxidase activation enhanced MMP-9 secretion and activity, determined by enzyme-linked immunosorbent assay and zymography, respectively. Immunohistochemical study showed that phagocytic NADPH oxidase localized with MMP-9 in endarterectomies from patients with carotid stenosis. In addition, a positive relationship (P<0.001) was found between phagocytic NADPH oxidase-dependent superoxide production determined with lucigenin and plasma MMP-9 levels in 188 asymptomatic subjects free of overt clinical atherosclerosis. In multivariate analysis, this association remained significant after adjustment for cardiovascular risk factors. Interestingly, subjects in the upper quartile of superoxide production exhibited the highest values of MMP-9, oxidized low-density lipoprotein, nitrotyrosine, carotid intima media thickness, and an increased presence of carotid plaques. CONCLUSIONS: Enhanced NADPH oxidase-dependent *O2(-) production stimulates MMP-9 in monocytes and this relationship may be relevant in the atherosclerotic process. Moreover, MMP-9 emerges as an important mediator of the phagocytic NADPH oxidase-dependent oxidative stress in atherosclerosis.


Assuntos
Doenças das Artérias Carótidas/enzimologia , Artéria Carótida Primitiva/enzimologia , Metaloproteinase 9 da Matriz/metabolismo , NADPH Oxidases/metabolismo , Superóxidos/metabolismo , Adulto , Análise de Variância , Doenças das Artérias Carótidas/fisiopatologia , Artéria Carótida Primitiva/patologia , Estudos de Casos e Controles , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Humanos , Leucócitos Mononucleares/enzimologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estresse Oxidativo/fisiologia , Oxigênio/metabolismo , Fagócitos/enzimologia , Probabilidade , Sensibilidade e Especificidade
15.
Diabetes ; 55(1): 209-15, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16380495

RESUMO

Oxidative stress plays a critical role in the pathogenesis of atherosclerosis in patients with metabolic syndrome. This study aimed to investigate whether a relationship exists between phagocytic NADPH oxidase activity and oxidative stress and atherosclerosis in metabolic syndrome patients. The study was performed in 56 metabolic syndrome patients (metabolic syndrome group), 99 patients with one or two cardiovascular risk factors (cardiovascular risk factor group), and 28 healthy subjects (control group). NADPH oxidase expression and activity was augmented (P < 0.05) in metabolic syndrome compared with cardiovascular risk factor and control groups. Insulin was enhanced (P < 0.05) in metabolic syndrome patients compared with cardiovascular risk factor and control groups and correlated with NADPH oxidase activity in the overall population. Insulin stimulated NADPH oxidase activity; this effect was abolished by a specific protein kinase C inhibitor. Oxidized LDL and nitrotyrosine levels and carotid intima-media thickness were increased (P < 0.05) in the metabolic syndrome group compared with cardiovascular risk factor and control groups and correlated with NADPH oxidase activity in the overall population. These findings suggest that phagocytic NADPH oxidase overactivity is involved in oxidative stress and atherosclerosis in metabolic syndrome patients. Our findings also suggest that hyperinsulinemia may contribute to oxidative stress in metabolic syndrome patients through activation of NADPH oxidase.


Assuntos
Síndrome Metabólica/enzimologia , NADPH Oxidases/metabolismo , Estresse Oxidativo/fisiologia , Fagócitos/enzimologia , Aterosclerose , Biomarcadores , Feminino , Regulação Enzimológica da Expressão Gênica , Humanos , Linfócitos/efeitos dos fármacos , Linfócitos/enzimologia , Masculino , Síndrome Metabólica/metabolismo , Pessoa de Meia-Idade , Monócitos/efeitos dos fármacos , Monócitos/enzimologia , Fagócitos/metabolismo , Acetato de Tetradecanoilforbol/farmacologia
16.
J Hypertens ; 25(8): 1620-6, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17620958

RESUMO

OBJECTIVE: Oxidative stress is implicated in hypertension and the NADPH oxidase systems constitute the main source of superoxide in vascular wall. We searched for new polymorphisms within the CYBA promoter, the human gene that encodes the p22phox protein, and studied their potential association with essential hypertension. DESIGN: A case-control study in a random sample of the general population. METHODS: CYBA polymorphisms were determined by restriction fragment length polymorphism and allelic discrimination. NADPH oxidase activity was quantified in phagocytic cells by chemiluminescence. RESULTS: We identified three novel polymorphisms, at positions -852, -675 and -536 from the ATG codon. Only the -675(A/T) polymorphism associated with essential hypertension. The prevalence of the TT genotype and the T allele frequency were significantly higher (P < 0.05) in hypertensives than in normotensives. Furthermore, TT hypertensives exhibited higher (P < 0.05) systolic blood pressure values than TA/AA hypertensives. Increased phagocytic NADPH oxidase activity was observed in TT subjects compared to TA and AA individuals (P < 0.05). Enhanced carotid intima-media thickness, a surrogate marker of atherosclerosis, was found in TT subjects compared to TA and AA individuals (P < 0.05). Finally, mutagenesis experiments demonstrated a functional role of this polymorphism on the CYBA promoter activity. CONCLUSION: The -675 (A/T) CYBA polymorphism may be a novel genetic marker associated with essential hypertension. Furthermore, TT subjects exhibit features of NADPH oxidase-mediated oxidative stress and asymptomatic atherosclerosis.


Assuntos
Hipertensão/genética , NADPH Oxidases/genética , Polimorfismo Genético , Alelos , Sequência de Bases , Linhagem Celular , Primers do DNA , Frequência do Gene , Humanos , Desequilíbrio de Ligação , NADPH Oxidases/metabolismo , Fagócitos/enzimologia , Fenótipo , Regiões Promotoras Genéticas
17.
Sci Rep ; 7: 41865, 2017 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-28157237

RESUMO

Excessive myocardial collagen deposition and cross-linking (CCL), a process regulated by lysyl oxidase (LOX), determines left ventricular (LV) stiffness and dysfunction. The angiotensin II antagonist losartan, metabolized to the EXP3179 and EXP3174 metabolites, reduces myocardial fibrosis and LV stiffness in hypertensive patients. Our aim was to investigate the differential influence of losartan metabolites on myocardial LOX and CCL in an experimental model of hypertension with myocardial fibrosis, and whether EXP3179 and EXP3174 modify LOX expression and activity in fibroblasts. In rats treated with NG-nitro-L-arginine methyl ester (L-NAME), administration of EXP3179 fully prevented LOX, CCL and connective tissue growth factor (CTGF) increase, as well as fibrosis, without normalization of blood pressure (BP). In contrast, administration of EXP3174 normalized BP and attenuated fibrosis but did not modify LOX, CCL and CTGF. In TGF-ß1-stimulated fibroblasts, EXP3179 inhibited CTGF and LOX expression and activity with lower IC50 values than EXP3174. Our results indicate that, despite a lower antihypertensive effect, EXP3179 shows higher anti-fibrotic efficacy than EXP3174, likely through its ability to prevent the excess of LOX and CCL. It is suggested that the anti-fibrotic effect of EXP3179 may be partially mediated by the blockade of CTGF-induced LOX in fibroblasts.


Assuntos
Anti-Hipertensivos/farmacologia , Losartan/análogos & derivados , Miocárdio/metabolismo , Disfunção Ventricular Esquerda/tratamento farmacológico , Animais , Anti-Hipertensivos/farmacocinética , Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea , Linhagem Celular , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Fibrose , Humanos , Losartan/farmacocinética , Losartan/farmacologia , Losartan/uso terapêutico , Masculino , Miocárdio/citologia , Miocárdio/patologia , Miofibroblastos/efeitos dos fármacos , Miofibroblastos/metabolismo , Proteína-Lisina 6-Oxidase/metabolismo , Ratos , Ratos Wistar , Fator de Crescimento Transformador beta/farmacologia , Disfunção Ventricular Esquerda/metabolismo
18.
Sci Rep ; 7: 40696, 2017 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-28091585

RESUMO

This study analyzed the potential associations of 7 myocardial fibrosis-related microRNAs with the quality of the collagen network (e.g., the degree of collagen fibril cross-linking or CCL) and the enzyme lysyl oxidase (LOX) responsible for CCL in 28 patients with severe aortic stenosis (AS) of whom 46% had a diagnosis of chronic heart failure (HF). MicroRNA expression was analyzed in myocardial and blood samples. From the studied microRNAs only miR-19b presented a direct correlation (p < 0.05) between serum and myocardium. Compared to controls both myocardial and serum miR-19b were reduced (p < 0.01) in AS patients. In addition, miR-19b was reduced in the myocardium (p < 0.01) and serum (p < 0.05) of patients with HF compared to patients without HF. Myocardial and serum miR-19b were inversely correlated (p < 0.05) with LOX, CCL and LV stiffness in AS patients. In in vitro studies miR-19b inhibition increased (p < 0.05) connective tissue growth factor protein and LOX protein expression in human fibroblasts. In conclusion, decreased miR-19b may be involved in myocardial LOX up-regulation and excessive CCL, and consequently increased LV stiffness in AS patients, namely in those with HF. Serum miR-19b can be a biomarker of these alterations of the myocardial collagen network in AS patients, particularly in patients with HF.


Assuntos
Estenose da Valva Aórtica/genética , Estenose da Valva Aórtica/metabolismo , Colágeno/metabolismo , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/metabolismo , MicroRNAs/genética , Miocárdio/metabolismo , Idoso , Estenose da Valva Aórtica/diagnóstico , Estenose da Valva Aórtica/tratamento farmacológico , Biomarcadores , Comorbidade , Ecocardiografia , Feminino , Fibrose , Regulação da Expressão Gênica , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/tratamento farmacológico , Testes de Função Cardíaca , Humanos , Masculino , MicroRNAs/sangue , Interferência de RNA , Transcriptoma
19.
J Hypertens ; 35(4): 853-861, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28253222

RESUMO

OBJECTIVE: Myocardial fibrosis is associated with alterations in the cross-linking and deposition of collagen type I (CCL and CD, respectively). We aimed to evaluate whether the combination of circulating biomarkers of CCL [the carboxy-terminal telopeptide of collagen type I to matrix metalloproteinase-1 ratio (CITP : MMP-1)] and CD [the carboxy-terminal propeptide of procollagen type I (PICP)] identifies myocardial fibrosis phenotypes with distinct clinical outcome in hypertensive patients with heart failure. METHODS: Endomyocardial biopsies and blood samples from 38 patients (small cohort), and blood samples from 203 patients (large cohort) were analyzed. Myocardial CCL and CD were assessed by histological methods. Serum PICP, CITP, and MMP-1 were determined by ELISA. RESULTS: Small cohort: CITP : MMP-1 cutoff 1.968 or less and PICP cutoff at least 110.8 ng/ml were used for predicting high CCL and severe CD, respectively. Large cohort: as defined by the above thresholds, patients were categorized into four subgroups based on the presence (+) or absence (-) of high CCL and severe CD. Compared with CCL-CD-, the adjusted hazard ratios for a composite end point of heart failure hospitalization or cardiovascular death over 5 years in CCL-CD+, CCL+CD-, and CCL+CD+ were 1.11 (P = 0.79), 1.99 (P = 0.07), and 2.18 (P = 0.04), respectively (P for trend = 0.005). In addition, the categorization based on CCL and CD yielded integrated discrimination (P = 0.03) and net reclassification (P = 0.01) improvements for the mentioned outcome. CONCLUSION: The combination of low serum CITP : MMP-1 ratio and high serum PICP identifies hypertensive patients with heart failure presenting with a phenotype of myocardial fibrosis characterized by the concurrence of excessive CCL and CD and associated with poor outcome.


Assuntos
Fibrose Endomiocárdica/sangue , Fibrose Endomiocárdica/patologia , Insuficiência Cardíaca/fisiopatologia , Hipertensão/fisiopatologia , Miocárdio/patologia , Biomarcadores/sangue , Biópsia , Colágeno Tipo I/sangue , Colágeno Tipo I/metabolismo , Insuficiência Cardíaca/complicações , Humanos , Hipertensão/complicações , Metaloproteinase 1 da Matriz/sangue , Fragmentos de Peptídeos/sangue , Peptídeos/sangue , Fenótipo , Pró-Colágeno/sangue , Prognóstico
20.
Med Clin North Am ; 101(1): 43-52, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27884234

RESUMO

The chronic hemodynamic load imposed by hypertension on the left ventricle leads to lesions in the myocardium that result in structural remodeling, which provides support for alterations in cardiac function, perfusion, and electrical activity that adversely influence the clinical evolution of hypertensive heart disease. Management must include detecting, reducing, and reversing left ventricular hypertrophy, as well as the detection and repair of microscopic lesions responsible for myocardial remodeling. Reducing the burden associated with hypertensive heart disease can be targeted using personalized treatment. The noninvasive, biomarker-mediated identification of subsets of patients with hypertensive heart disease is essential to provide personalized treatment.


Assuntos
Cardiopatias/patologia , Hipertensão/patologia , Hipertensão/fisiopatologia , Microvasos/patologia , Miocárdio/patologia , Miócitos Cardíacos/patologia , Adaptação Fisiológica , Apoptose , Vasos Coronários/patologia , Fibrose , Cardiopatias/tratamento farmacológico , Cardiopatias/etiologia , Humanos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Hipertrofia/patologia , Miócitos Cardíacos/fisiologia
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