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2.
Cell Stem Cell ; 24(4): 579-591.e12, 2019 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-30853557

RESUMO

Heart disease is a paramount cause of global death and disability. Although cardiomyocyte death plays a causal role and its suppression would be logical, no clinical counter-measures target the responsible intracellular pathways. Therapeutic progress has been hampered by lack of preclinical human validation. Mitogen-activated protein kinase kinase kinase kinase-4 (MAP4K4) is activated in failing human hearts and relevant rodent models. Using human induced-pluripotent-stem-cell-derived cardiomyocytes (hiPSC-CMs) and MAP4K4 gene silencing, we demonstrate that death induced by oxidative stress requires MAP4K4. Consequently, we devised a small-molecule inhibitor, DMX-5804, that rescues cell survival, mitochondrial function, and calcium cycling in hiPSC-CMs. As proof of principle that drug discovery in hiPSC-CMs may predict efficacy in vivo, DMX-5804 reduces ischemia-reperfusion injury in mice by more than 50%. We implicate MAP4K4 as a well-posed target toward suppressing human cardiac cell death and highlight the utility of hiPSC-CMs in drug discovery to enhance cardiomyocyte survival.


Assuntos
Doxorrubicina/farmacologia , Infarto/tratamento farmacológico , Infarto/patologia , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Feminino , Humanos , Peróxido de Hidrogênio/farmacologia , Células-Tronco Pluripotentes Induzidas/citologia , Infarto/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Miócitos Cardíacos/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Relação Estrutura-Atividade
3.
FASEB J ; 33(1): 711-721, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30024790

RESUMO

Coordinated changes in signaling pathways and gene expression in hearts subjected to prolonged stress maintain cardiac function. Loss of steroid receptor coactivator-2 (SRC-2) results in a reversal to the fetal gene program and disrupts the response to pressure overload, accompanied by prominent effects on metabolism and growth signaling, including increased AMPK activation. We proposed that early metabolic stress driven by AMPK activation induces contractile dysfunction in mice lacking SRC-2. We used 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) to activate AMPK transiently before transverse aortic constriction (TAC) in wild-type and cardiomyocyte-specific SRC-2 knockout (CKO) animals. In contrast to AMPK activities during stress, in unstressed hearts, AICAR induced a mild activation of Akt signaling, and, in SRC-2-CKO mice, partially relieved an NAD+ deficiency and increased antioxidant signaling. These molecular changes translated to a mild hypertrophic response to TAC with decreased maladaptive remodeling, including markedly decreased fibrosis. Additionally, preactivation of AMPK in SRC-2-CKO mice was accompanied by a dramatic improvement in cardiac function compared with saline-treated SRC-2-CKO mice. Our results show that altered molecular signaling before stress onset has extended effects on sustained cardiac stress responses, and prestress modulation of transient growth and metabolism pathways may control those effects.-Nam, D. H., Kim, E., Benham, A., Park, H.-K., Soibam, B., Taffet, G. E., Kaelber, J. T., Suh, J. H., Taegtmeyer, H., Entman, M. L., Reineke, E. L. Transient activation of AMPK preceding left ventricular pressure overload reduces adverse remodeling and preserves left ventricular function.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Aminoimidazol Carboxamida/análogos & derivados , Cardiomegalia/prevenção & controle , Coativador 2 de Receptor Nuclear/fisiologia , Ribonucleotídeos/farmacologia , Função Ventricular Esquerda/fisiologia , Pressão Ventricular , Remodelação Ventricular/fisiologia , Proteínas Quinases Ativadas por AMP/genética , Aminoimidazol Carboxamida/farmacologia , Animais , Cardiomegalia/etiologia , Cardiomegalia/metabolismo , Hipoglicemiantes/farmacologia , Masculino , Camundongos , Camundongos Knockout , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Disfunção Ventricular Esquerda/prevenção & controle , Função Ventricular Esquerda/efeitos dos fármacos , Remodelação Ventricular/efeitos dos fármacos
4.
J Gerontol A Biol Sci Med Sci ; 73(9): 1167-1177, 2018 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-29538624

RESUMO

Metabolic, inflammatory, and functional changes occur in cardiovascular aging which may stem from oxidative stress and be remediable with antioxidants. Glutathione, an intracellular antioxidant, declines with aging, and supplementation with glutathione precursors, N-acetyl cysteine (NAC) and glycine (Gly), increases tissue glutathione. Thirty-month old mice were fed diets supplemented with NAC or NAC+Gly and, after 7 weeks, cardiac function and molecular studies were performed. The NAC+Gly supplementation improved diastolic function, increasing peak early filling velocity, and reducing relaxation time, left atrial volume, and left ventricle end diastolic pressure. By contrast, cardiac function did not improve with NAC alone. Both diet supplementations decreased cardiac levels of inflammatory mediators; only NAC+Gly reduced leukocyte infiltration. Several mitochondrial genes reduced with aging were upregulated in hearts by NAC+Gly diet supplementation. These Krebs cycle and oxidative phosphorylation enzymes, suggesting improved mitochondrial function, and permeabilized cardiac fibers from NAC+Gly-fed mice produced ATP from carbohydrate and fatty acid sources, whereas fibers from control old mice were less able to utilize fatty acids. Our data indicate that NAC+Gly supplementation can improve diastolic function in the old mouse and may have potential to prevent important morbidities for older people.


Assuntos
Acetilcisteína/metabolismo , Envelhecimento/fisiologia , Fenômenos Fisiológicos Cardiovasculares/efeitos dos fármacos , Dietoterapia/métodos , Suplementos Nutricionais , Glicina/metabolismo , Animais , Antioxidantes/metabolismo , Senescência Celular/fisiologia , Glutationa/metabolismo , Inflamação/metabolismo , Camundongos , Mitocôndrias/metabolismo , Estresse Oxidativo
5.
Kidney Int ; 93(1): 81-94, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28739141

RESUMO

Chronic kidney disease is a major cause of death, and renal fibrosis is a common pathway leading to the progression of this disease. Although activated fibroblasts are responsible for the production of the extracellular matrix and the development of renal fibrosis, the molecular mechanisms underlying fibroblast activation are not fully defined. Here we examined the functional role of AMP-activated protein kinase (AMPK) in the activation of fibroblasts and the development of renal fibrosis. AMPKα1 was induced in the kidney during the development of renal fibrosis. Mice with global or fibroblast-specific knockout of AMPKα1 exhibited fewer myofibroblasts, developed less fibrosis, and produced less extracellular matrix protein in the kidneys following unilateral ureteral obstruction or ischemia-reperfusion injury. Mechanistically, AMPKα1 directly phosphorylated cofilin leading to cytoskeleton remodeling and myocardin-related transcription factor-A nuclear translocation resulting in fibroblast activation and extracellular matrix protein production. Thus, AMPK may be a critical regulator of fibroblast activation through regulation of cytoskeleton dynamics and myocardin-related transcription factor-A nuclear translocation. Hence, AMPK signaling may represent a novel therapeutic target for fibrotic kidney disease.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Fibroblastos/enzimologia , Rim/enzimologia , Miofibroblastos/enzimologia , Insuficiência Renal Crônica/enzimologia , Traumatismo por Reperfusão/enzimologia , Transativadores/metabolismo , Proteínas Quinases Ativadas por AMP/deficiência , Proteínas Quinases Ativadas por AMP/genética , Transporte Ativo do Núcleo Celular , Animais , Cofilina 1/metabolismo , Modelos Animais de Doenças , Matriz Extracelular/metabolismo , Matriz Extracelular/patologia , Fibroblastos/patologia , Fibrose , Células HEK293 , Humanos , Rim/patologia , Masculino , Camundongos Knockout , Mutação , Miofibroblastos/patologia , Fosforilação , Insuficiência Renal Crônica/etiologia , Insuficiência Renal Crônica/genética , Insuficiência Renal Crônica/patologia , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/patologia , Transdução de Sinais , Fatores de Transcrição/metabolismo , Obstrução Ureteral/complicações
6.
J Biol Chem ; 292(52): 21643-21652, 2017 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-29127200

RESUMO

Pressure overload-induced cardiac stress induces left ventricular hypertrophy driven by increased cardiomyocyte mass. The increased energetic demand and cardiomyocyte size during hypertrophy necessitate increased fuel and oxygen delivery and stimulate angiogenesis in the left ventricular wall. We have previously shown that the transcriptional regulator steroid receptor coactivator-2 (SRC-2) controls activation of several key cardiac transcription factors and that SRC-2 loss results in extensive cardiac transcriptional remodeling. Pressure overload in mice lacking SRC-2 induces an abrogated hypertrophic response and decreases sustained cardiac function, but the cardiomyocyte-specific effects of SRC-2 in these changes are unknown. Here, we report that cardiomyocyte-specific loss of SRC-2 (SRC-2 CKO) results in a blunted hypertrophy accompanied by a rapid, progressive decrease in cardiac function. We found that SRC-2 CKO mice exhibit markedly decreased left ventricular vasculature in response to transverse aortic constriction, corresponding to decreased expression of the angiogenic factor VEGF. Of note, SRC-2 knockdown in cardiomyocytes decreased VEGF expression and secretion to levels sufficient to blunt in vitro tube formation and proliferation of endothelial cells. During pressure overload, both hypertrophic and hypoxic signals can stimulate angiogenesis, both of which stimulated SRC-2 expression in vitro Furthermore, SRC-2 coactivated the transcription factors GATA-binding protein 4 (GATA-4) and hypoxia-inducible factor (HIF)-1α and -2α in response to angiotensin II and hypoxia, respectively, which drive VEGF expression. These results suggest that SRC-2 coordinates cardiomyocyte secretion of VEGF downstream of the two major angiogenic stimuli occurring during pressure overload bridging both hypertrophic and hypoxia-stimulated paracrine signaling.


Assuntos
Coativador 2 de Receptor Nuclear/metabolismo , Indutores da Angiogênese/metabolismo , Angiotensina II/metabolismo , Animais , Ventrículos do Coração/metabolismo , Hipertrofia Ventricular Esquerda/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Camundongos , Camundongos Knockout , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/fisiologia , Neovascularização Patológica/metabolismo , Comunicação Parácrina/fisiologia , Ativação Transcricional , Fator A de Crescimento do Endotélio Vascular/metabolismo , Remodelação Ventricular
7.
J Mol Cell Cardiol ; 111: 81-85, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28826664

RESUMO

In 2030, elderly people will represent 20% of the United States population. Even now, chronic cardiac diseases, especially heart failure with preserved systolic function (HFpEF), are the most expensive DRGs for Medicare. Progressive interstitial fibrosis in the aging heart is well recognized as an important component of HFpEF. Our recent studies suggested an important pathophysiologic role for reduced TGF-ß receptor 1 (TGFßR1) signaling in mesenchymal stem cells (MSCs) and their mesenchymal fibroblast progeny in the development of interstitial fibrosis. This report arises from our previous studies, which suggest that an inflammatory phenotype exists in these mesenchymal fibroblasts as a result of a reduced TGF-ß-Smad-dependent pathway but upregulated farnesyltransferase (FTase)-Ras-Erk signaling. In this report we provide evidence for a therapeutic approach that downregulates Erk activation through an adenosine monophosphate-activated kinase (AMPK) pathway. Aging C57BL/6J mice were treated with AICAR (an AMPK activator) for a 30-day period. This treatment suppressed excessive monocyte chemoattractant protein-1 (MCP-1) generation, which diminished leukocyte infiltration and in consequence suppressed the formation of macrophage-derived myeloid fibroblasts. Interestingly, the number of mesenchymal fibroblasts was also reduced. In addition, we observed changes in extracellular matrix (ECM) deposition, specifically that collagen type I and the alternatively spliced variant of fibronectin (EDA) expressions were reduced. These data suggest that the upregulation of AMPK activity is a potential therapeutic approach to fibrosis in the aging heart.


Assuntos
Envelhecimento/patologia , Aminoimidazol Carboxamida/análogos & derivados , Fibroblastos/patologia , Inflamação/patologia , Ribonucleotídeos/farmacologia , Aminoimidazol Carboxamida/farmacologia , Animais , Biomarcadores/metabolismo , Contagem de Células , Fibroblastos/efeitos dos fármacos , Fibrose , Masculino , Camundongos Endogâmicos C57BL , Miocárdio/patologia
8.
Basic Res Cardiol ; 112(4): 34, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28478479

RESUMO

Aging is associated with increased cardiac interstitial fibrosis and diastolic dysfunction. Our previous study has shown that mesenchymal fibroblasts in the C57BL/6J (B6J) aging mouse heart acquire an inflammatory phenotype and produce higher levels of chemokines. Monocyte chemoattractant protein-1 (MCP-1) secreted by these aged fibroblasts promotes leukocyte uptake into the heart. Some of the monocytes that migrate into the heart polarize into M2a macrophages/myeloid fibroblasts. The number of activated mesenchymal fibroblasts also increases with age, and consequently, both sources of fibroblasts contribute to fibrosis. Here, we further investigate mechanisms by which inflammation influences activation of myeloid and mesenchymal fibroblasts and their collagen synthesis. We examined cardiac fibrosis and heart function in three aged mouse strains; we compared C57BL/6J (B6J) with two other strains that have reduced inflammation via different mechanisms. Aged C57BL/6N (B6N) hearts are protected from oxidative stress and fibroblasts derived from them do not develop an inflammatory phenotype. Likewise, these mice have preserved diastolic function. Aged MCP-1 null mice on the B6J background (MCP-1KO) are protected from elevated leukocyte infiltration; they develop moderate but reduced fibrosis and diastolic dysfunction. Based on these studies, we further delineated the role of resident versus monocyte-derived M2a macrophages in myeloid-dependent fibrosis and found that the number of monocyte-derived M2a (but not resident) macrophages correlates with age-related fibrosis and diastolic dysfunction. In conclusion, we have found that ROS and inflammatory mediators are necessary for activation of fibroblasts of both developmental origins, and prevention of either led to better functional outcomes.


Assuntos
Envelhecimento/patologia , Cardiomiopatias/patologia , Linhagem da Célula , Fibroblastos/patologia , Inflamação/patologia , Macrófagos/patologia , Miocárdio/patologia , Fatores Etários , Envelhecimento/genética , Envelhecimento/metabolismo , Animais , Cardiomiopatias/genética , Cardiomiopatias/metabolismo , Cardiomiopatias/fisiopatologia , Comunicação Celular , Células Cultivadas , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Diástole , Fibroblastos/metabolismo , Fibrose , Inflamação/genética , Inflamação/metabolismo , Ativação de Macrófagos , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miocárdio/metabolismo , Estresse Oxidativo , Fenótipo , Disfunção Ventricular Esquerda/metabolismo , Disfunção Ventricular Esquerda/patologia , Disfunção Ventricular Esquerda/fisiopatologia , Função Ventricular Esquerda
9.
Artigo em Inglês | MEDLINE | ID: mdl-27738646

RESUMO

The participation of C-reactive protein (CRP) in host defense against microorganisms has been well described. More controversial has been its role in chronic conditions such as cardiovascular disease. Our recent publications explain the reasons for some of the confusion concerning CRP as a risk factor for disease and whether it is pro-inflammatory or anti-inflammatory. We found that two isoforms of CRP, pentameric (pCRP) and monomeric (mCRP), on microparticles (MPs), were not measureable by standard clinical assays. When we investigated MPs by imaging cytometry in plasma from controls versus patients with peripheral artery disease, we found that MPs from endothelial cells bearing mCRP were elevated. This elevation did not correlate with the soluble pCRP measured by high-sensitivity CRP assays. The data suggest that detection of mCRP on MPs may be a more specific marker in diagnosis, measurement of progression, and risk sensitivity in chronic disease. In an in vitro model of vascular inflammation, pCRP was anti-inflammatory and mCRP was pro-inflammatory for macrophage and T cell polarization. When we further investigated pCRP under defined conditions, we found that pCRP in the absence of a phosphocholine ligand had no inflammatory consequences. When combined with phosphocholine ligands, pCRP signaled through two Fcγ receptors (FcγRI and FcγRII) via phosphorylation of spleen tyrosine kinase (pSYK) to activate monocytes. Phosphocholine itself, when bound to pCRP, induced a congruent M2 macrophage and Th2 response. Phosphocholine is also the head group on the lipid phosphatidylcholine, which can become oxidized. Liposomes bearing oxidized phosphatidylcholine without pCRP promoted a uniform M1 macrophage and Th1 pro-inflammatory response. When oxidized liposomes were bound to pCRP, there was a disjunction in the macrophage and T cell response: monocytes matured into M2 macrophages, but the T cells polarized into a Th1 phenotype. The CRP-bound liposomes signaled monocytes via FcγRII to promote an anti-inflammatory M2 macrophage state, whereas the lack of FcγR on T cells allowed their liposome-induced polarization to a pro-inflammatory Th1 phenotype unopposed by the contribution of the pCRP/FcγR interaction. Different isoforms of CRP and its binding to complex ligands may determine its biological activities and their contribution to inflammatory states.

10.
Immun Inflamm Dis ; 4(3): 274-88, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27621811

RESUMO

INTRODUCTION: We studied monocyte transendothelial migration and subsequent polarization into M1/M2 macrophages in response to C-reactive protein (CRP) with two disease-related ligands: (1) phosphocholine (PC) and (2) multilamellar liposomes containing both unoxidized and oxidized forms of the lipid, phosphatidylcholine. These ligands differ in biological origin: PC is present on bacterial cell walls while oxidized lipids are present in atherogenic lipids. METHODS: We used an in vitro model of human monocyte transendothelial migration and assessed the polarization of monocytes and T cells and signaling through Fcγ receptors in monocytes. RESULTS: CRP without ligands did not promote M2 macrophage differentiation over background levels. However, when paired with either ligand, it increased M2 numbers. M2 differentiation was dependent on IL-13, and in the case of CRP with PC, was associated with a Th2 response. Paradoxically, while CRP with PC initiated a Th2 response, the combination of liposomes with CRP resulted in a Th1 response without any change in Th2 numbers despite association with M2 macrophage polarization. To resolve the conundrum of an anti-inflammatory macrophage response coexisting with a proinflammatory T cell response, we investigated signaling of CRP and its ligands through Fcγ receptors, which leads to macrophage activation independent of T cell signaling. We found that CRP plus PC acted via FcγRI, whereas CRP with liposomes bound to FcγRII. Both were activating signals as evidenced by SYK phosphorylation. CONCLUSION: We conclude that CRP with ligands can promote M2 macrophage differentiation to fibroblasts through FcγR activation, and this may result in an anti-inflammatory influence despite a proinflammatory T cell environment caused by oxidized lipids. The potential relationship of this mechanism to chronic inflammatory disease is discussed.

11.
Physiol Rep ; 4(8)2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27125666

RESUMO

Angiotensin-II (Ang-II) infusion is associated with the development of interstitial fibrosis in both heart and kidney as a result of chemokine-dependent uptake of monocytes and subsequent development of myeloid fibroblasts. This study emphasizes on the synergistic role of tumor necrosis factor (TNF) on the time course of Ang-II-induced fibrosis and inflammation in heart and kidney. In wild-type (WT) hearts, Ang-II-induced fibrosis peaked within 1 week of infusion and remained stable over a 6-week period, while the myeloid fibroblasts disappeared; TNF receptor-1-knockout (TNFR1-KO) hearts did not develop a myeloid response or cardiac fibrosis during this time. WT hearts developed more accelerated cardiac hypertrophy and remodeling than TNFR1-KO In the kidney, 1-week Ang-II infusion did not evoke a fibrotic response; however, after 6 weeks, WT kidneys displayed modest but significant tubulointerstitial collagen deposition associated with the appearance of myeloid cells and profibrotic gene activation. Renal fibrosis was not seen in Ang-II-infused TNFR1-KO By contrast, while hypertension increased and cardiac function decreased more slowly in TNFR1-KO than WT, they were equivalently abnormal at 6 weeks. Similarly, serum markers for renal dysfunction were not different after 6 weeks. In conclusion, Ang-II infusion initiated fibroinflammatory responses with different time courses in heart and kidney, both requiring TNFR1 signaling, and both associated with monocyte-derived myeloid fibroblasts. TNFR1 deletion obviated the fibroinflammatory effects of Ang-II, but did not alter changes in blood pressure and cardiorenal function after 6 weeks. Thus, the synergy of TNF with Ang-II targets the fibroinflammatory component of Ang-II signaling.


Assuntos
Angiotensina II/metabolismo , Cardiopatias/metabolismo , Nefropatias/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Angiotensina II/farmacologia , Animais , Ensaio de Imunoadsorção Enzimática , Fibroblastos/efeitos dos fármacos , Fibrose/metabolismo , Fibrose/patologia , Citometria de Fluxo , Coração/efeitos dos fármacos , Cardiopatias/patologia , Inflamação/metabolismo , Inflamação/patologia , Rim/efeitos dos fármacos , Nefropatias/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores Tipo I de Fatores de Necrose Tumoral/deficiência , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Necrose Tumoral alfa/farmacologia
12.
J Cardiovasc Transl Res ; 9(3): 184-93, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26891844

RESUMO

C-reactive protein (CRP) as an indicator of cardiovascular disease (CVD) has shown limited sensitivity. We demonstrate that two isoforms of CRP (pentameric, pCRP and monomeric, mCRP) present in soluble form or on microparticles (MPs) have different biological effects and are not all measured by clinical CRP assays. The high-sensitivity CRP assay (hsCRP) did not measure pCRP or mCRP on MPs, whereas flow cytometry did. MPs derived from endothelial cells, particularly those bearing mCRP, were elevated in peripheral artery disease (PAD) patients compared to controls. The numbers of mCRP(+) endothelial MPs did not correlate with hsCRP measurements of soluble pCRP, indicating their independent modulation. In controls, statins lowered mCRP(+) endothelial MPs. In a model of vascular inflammation, mCRP induced endothelial shedding of MPs and was proinflammatory, while pCRP was anti-inflammatory. mCRP on endothelial MPs may be both an unmeasured indicator of, and an amplifier of, vascular disease, and its detection might improve risk sensitivity.


Assuntos
Proteína C-Reativa/metabolismo , Micropartículas Derivadas de Células/metabolismo , Células Endoteliais/metabolismo , Mediadores da Inflamação/sangue , Doença Arterial Periférica/sangue , Idoso , Biomarcadores/sangue , Estudos de Casos e Controles , Micropartículas Derivadas de Células/efeitos dos fármacos , Células Cultivadas , Células Endoteliais/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Masculino , Pessoa de Meia-Idade , Doença Arterial Periférica/diagnóstico , Doença Arterial Periférica/tratamento farmacológico , Projetos Piloto , Regulação para Cima
13.
J Mol Cell Cardiol ; 91: 28-34, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26718722

RESUMO

Pathologic fibrosis in the aging mouse heart is associated with dysregulated resident mesenchymal stem cells (MSC) arising from reduced stemness and aberrant differentiation into dysfunctional inflammatory fibroblasts. Fibroblasts derived from aging MSC secrete higher levels of 1) collagen type 1 (Col1) that directly contributes to fibrosis, 2) monocyte chemoattractant protein-1 (MCP-1) that attracts leukocytes from the blood and 3) interleukin-6 (IL-6) that facilitates transition of monocytes into myeloid fibroblasts. The transcriptional activation of these proteins is controlled via the farnesyltransferase (FTase)-Ras-Erk pathway. The intrinsic change in the MSC phenotype acquired by advanced age is specific for the heart since MSC originating from bone wall (BW-MSC) or fibroblasts derived from them were free of these defects. The potential therapeutic interventions other than clinically approved strategies based on findings presented in this review are discussed as well. This article is a part of a Special Issue entitled "Fibrosis and Myocardial Remodeling".


Assuntos
Envelhecimento/patologia , Fibroblastos/citologia , Células-Tronco Mesenquimais/citologia , Células Mieloides/citologia , Miocárdio/patologia , Envelhecimento/metabolismo , Alquil e Aril Transferases/genética , Alquil e Aril Transferases/metabolismo , Animais , Citocinas/genética , Citocinas/metabolismo , Epigênese Genética , Fibroblastos/metabolismo , Fibrose , Humanos , Inflamação , Insulina/genética , Insulina/metabolismo , Células-Tronco Mesenquimais/metabolismo , Camundongos , Células Mieloides/metabolismo , Miocárdio/metabolismo , Transdução de Sinais , ras-GRF1/genética , ras-GRF1/metabolismo
14.
J Gerontol A Biol Sci Med Sci ; 71(9): 1141-50, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-26511013

RESUMO

Impaired cardiac diastolic function occurs with aging in many species and may be difficult to measure noninvasively. In humans, left atrial (LA) volume is a robust measure of chronic diastolic function as the LA is exposed to increased left ventricular filling pressures. We hypothesized that LA volume would be a useful indicator of diastolic function in aging mice. Further, we asked whether pressures were propagated backwards affecting pulmonary arteries (PAs) and right ventricle (RV). We measured LA, PA, and RV infundibulum dimensions with echocardiography and used mouse-specific Doppler systems and pressure catheters for noninvasive and invasive measures. As C57BL/6 mice aged from 3 to 29-31 months, LA volume almost tripled. LA volume increases correlated with traditional diastolic function measures. Within groups of 14- and 31-month-old mice, LA volume correlated with diastolic function measured invasively. In serial studies, mice evaluated at 20 and 24 months showed monotonic increases in LA volume; other parameters changed less predictably. PA diameters, larger in 30-month-old mice than 6-month-old mice, correlated with LA volumes. Noninvasive LA volume and PA diameter assessments are useful and state independent measures of diastolic function in mice, correlating with other measures of diastolic dysfunction in aging. Furthermore, serial measurements over 4 months demonstrated consistent increases in LA volume suitable for longitudinal cardiac aging studies.


Assuntos
Envelhecimento , Função do Átrio Esquerdo , Átrios do Coração , Insuficiência Cardíaca Diastólica , Artéria Pulmonar , Animais , Diástole , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/patologia , Insuficiência Cardíaca Diastólica/diagnóstico por imagem , Camundongos , Camundongos Endogâmicos C57BL , Valor Preditivo dos Testes , Artéria Pulmonar/diagnóstico por imagem , Artéria Pulmonar/patologia , Sensibilidade e Especificidade , Ultrassonografia Doppler/métodos
15.
Artigo em Inglês | MEDLINE | ID: mdl-26366423

RESUMO

OBJECTIVES: The goal of this study was to investigate the association between collagen metabolism biomarkers and health related quality of life (HRQoL) in PAH patients. METHODS: We prospectively enrolled 68 stable idiopathic, anorexigen-associated, and hereditary PAH subjects and 37 healthy controls. Serum samples were analyzed for N-terminal propeptide of type III procollagen (PIIINP), c-terminal telopeptide of collagen type I (CITP), matrix metalloproteinase 9 (MMP-9) and tissue inhibitor of metalloproteinase 1 (TIMP-1). The Minnesota Living with Heart Failure (MLWHF), Euro QoL-5D (EQ-5D), Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) and Short Form (SF-36) general health survey were administered at the time of blood draw. General linear models, as well as logistic regression models were used to assess associations between variables. RESULTS: CITP, PIIINP, MMP9, and TIMP1 levels, and all HRQoL domains were significantly different between controls and PAH patients (p<0.001 for each). Interestingly, PIIINP levels were significantly associated with MLWHF physical (coef=1.63, and p=0.02), SF-36 physical (coef=-2.93, p=0.004), and EQ-5D aggregate (coef=0.34, p=0.001) scores. Several of the CAMPHOR scores strongly linearly associated with PIIINP. The odds of obtaining a walk distance ≥330 meters decrease by 38% per unit increase in PIIINP (OR=0.62; 95% CI=0.43, 0.90) and a PIIINP cutoff of 5.53 µg/L provided 81% sensitivity and 82% specificity. CONCLUSIONS: PIIINP is a good predictor of disease severity, and is strongly related to HRQoL scores in PAH patients. These relationships suggest PIIINP as a promising tool for PAH clinicians to determine or confirm the level of disease severity.

16.
J Clin Invest ; 125(7): 2759-71, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-26075818

RESUMO

Ischemic heart disease is the leading cause of heart failure. Both clinical trials and experimental animal studies demonstrate that chronic hypoxia can induce contractile dysfunction even before substantial ventricular damage, implicating a direct role of oxygen in the regulation of cardiac contractile function. Prolyl hydroxylase domain (PHD) proteins are well recognized as oxygen sensors and mediate a wide variety of cellular events by hydroxylating a growing list of protein substrates. Both PHD2 and PHD3 are highly expressed in the heart, yet their functional roles in modulating contractile function remain incompletely understood. Here, we report that combined deletion of Phd2 and Phd3 dramatically decreased expression of phospholamban (PLN), resulted in sustained activation of calcium/calmodulin-activated kinase II (CaMKII), and sensitized mice to chronic ß-adrenergic stress-induced myocardial injury. We have provided evidence that thyroid hormone receptor-α (TR-α), a transcriptional regulator of PLN, interacts with PHD2 and PHD3 and is hydroxylated at 2 proline residues. Inhibition of PHDs increased the interaction between TR-α and nuclear receptor corepressor 2 (NCOR2) and suppressed Pln transcription. Together, these observations provide mechanistic insight into how oxygen directly modulates cardiac contractility and suggest that cardiac function could be modulated therapeutically by tuning PHD enzymatic activity.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Miocárdio/metabolismo , Pró-Colágeno-Prolina Dioxigenase/metabolismo , Receptores Adrenérgicos beta/metabolismo , Animais , Sinalização do Cálcio , Proteínas de Ligação ao Cálcio/genética , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Células Cultivadas , Feminino , Humanos , Hidroxilação , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Prolina Dioxigenases do Fator Induzível por Hipóxia/deficiência , Prolina Dioxigenases do Fator Induzível por Hipóxia/genética , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Contração Miocárdica/fisiologia , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/patologia , Isquemia Miocárdica/fisiopatologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Correpressor 2 de Receptor Nuclear/metabolismo , Pró-Colágeno-Prolina Dioxigenase/deficiência , Pró-Colágeno-Prolina Dioxigenase/genética , Ratos , Estresse Fisiológico , Receptores alfa dos Hormônios Tireóideos/metabolismo
17.
FASEB J ; 29(8): 3160-70, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25888601

RESUMO

Fibrosis in the old mouse heart arises partly as a result of aberrant mesenchymal fibroblast activation. We have previously shown that endogenous mesenchymal stem cells (MSCs) in the aged heart are markedly resistant to TGF-ß signaling. Fibroblasts originating from these MSCs retain their TGF-ß unresponsiveness and become inflammatory. In current studies, we found that these inflammatory fibroblasts secreted higher levels of IL-6 (3-fold increase, P < 0.05) when compared with fibroblasts derived from the young hearts. Elevated IL-6 levels in fibroblasts derived from old hearts arose from up-regulated expression of Ras protein-specific guanine nucleotide releasing factor 1 (RasGrf1), a Ras activator (5-fold, P < 0.01). Knockdown of RasGrf1 by gene silencing or pharmacologic inhibition of farnesyltransferase (FTase) or ERK caused reduction of IL-6 mRNA (more than 65%, P < 0.01) and decreased levels of secreted IL-6 (by 44%, P < 0.01). In vitro, IL-6 markedly increased monocyte chemoattractant protein-1-driven monocyte-to-myeloid fibroblast formation after transendothelial migration (TEM; 3-fold, P < 0.01). In conclusion, abnormal expression of RasGrf1 promoted production of IL-6 by mesenchymal fibroblasts in the old heart. Secreted IL-6 supported conversion of monocyte into myeloid fibroblasts. This process promotes fibrosis and contributes to the diastolic dysfunction in the aging heart.


Assuntos
Envelhecimento/metabolismo , Fibroblastos/metabolismo , Inflamação/metabolismo , Interleucina-6/metabolismo , Células-Tronco Mesenquimais/metabolismo , Monócitos/metabolismo , Células Mieloides/metabolismo , Animais , Células Cultivadas , Fibroblastos/fisiologia , Fibrose/metabolismo , Fibrose/patologia , Coração/fisiopatologia , Inflamação/patologia , Masculino , Células-Tronco Mesenquimais/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/fisiologia , Células Mieloides/fisiologia , Fator de Crescimento Transformador beta/metabolismo
18.
Circ Heart Fail ; 8(2): 352-61, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25550440

RESUMO

BACKGROUND: Continuous angiotensin-II infusion induced the uptake of monocytic fibroblast precursors that initiated the development of cardiac fibrosis; these cells and concurrent fibrosis were absent in mice lacking tumor necrosis factor receptor 1 (TNFR1). We now investigated their cellular origin and temporal uptake and the involvement of TNFR1 in monocyte-to-fibroblast differentiation. METHODS AND RESULTS: Within a day, angiotensin-II induced a proinflammatory environment characterized by production of inflammatory chemokines, cytokines, and TH1-interleukins and uptake of bone marrow-derived M1 cells. After a week, the cardiac environment changed to profibrotic with growth factor and TH2-interleukin synthesis, uptake of bone marrow-derived M2 cells, and the presence of M2-related fibroblasts. TNFR1 signaling was not necessary for early M1 uptake, but its absence diminished the amount of M2 cells. TNFR1-knockout hearts also showed reduced levels of cytokine expression, but not of TH-related lymphokines. Reconstitution of wild-type bone marrow into TNFR1-knockout mice was sufficient to restore M2 uptake, upregulation of proinflammatory and profibrotic genes, and development of fibrosis in response to angiotensin-II. We also developed an in vitro mouse monocyte-to-fibroblast maturation assay that confirmed the essential role of TNFR1 in the sequential progression of monocyte activation and fibroblast formation. CONCLUSIONS: Development of cardiac fibrosis in response to angiotensin-II was mediated by myeloid precursors and consisted of 2 stages. A primary M1 inflammatory response was followed by a subsequent M2 fibrotic response. Although the first phase seemed to be independent of TNFR1 signaling, the later phase (and development of fibrosis) was abrogated by deletion of TNFR1.


Assuntos
Angiotensina II/imunologia , Miocárdio/patologia , Miócitos Cardíacos/imunologia , Receptores Tipo I de Fatores de Necrose Tumoral/fisiologia , Fator de Necrose Tumoral alfa/imunologia , Animais , Ensaios de Migração Celular , Feminino , Fibroblastos/metabolismo , Fibrose , Mediadores da Inflamação/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miocárdio/imunologia , Miócitos Cardíacos/patologia , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Remodelação Ventricular/fisiologia
19.
J Pulm Respir Med ; 5(5)2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27170847

RESUMO

OBJECTIVES: It is not known whether aldosterone levels are associated with increased mortality in patients with pulmonary arterial hypertension (PAH). The primary goal of this study was to determine whether circulating aldosterone levels predict severity of PAH in terms of hemodynamic characteristics and mortality. METHODS: Patients with stable PAH were enrolled at the Baylor PH program. The plasma levels of aldosterone and BNP were measured. Clinical, hemodynamic, and outcome data was collected by chart review. Mean follow up time from study enrollment was 39 ± 102 months. Cox proportional hazards model was used to assess time to death. RESULTS: There were 125 PAH patients with plasma aldosterone levels. Median aldosterone level was 9.9 pg/ml (25th-75th percentile: 4.1 pg/ml, 27.1 pg/ml) and median brain natriuretic peptide (BNP) level was 67.5 pg/ml (25th-75th percentile: 31 pg/ml, 225 pg/ml). Aldosterone levels were not significantly associated with BNP levels, six-minute walk distance, Borg dyspnea score, right ventricular systolic pressure, cardiac output and cardiac index. However, the association between aldosterone and right atrial pressure was dependent on mineralocorticoid receptor blocker treatment (Coef. =2.88, 95CI: 1.19, 4.56, p=0.001). By log-rank statistic there was no statistical difference between the survival of patients divided by median aldosterone level (p=0.914). However, there was a significant difference in patient survival between the BNP categories (p<0.001) such that those with high BNP level (>180 pg/mL) had a shorter survival time. CONCLUSIONS: The aldosterone level was not associated with increased mortality in PAH but was a marker of disease severity.

20.
Arterioscler Thromb Vasc Biol ; 34(7): 1422-8, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24855055

RESUMO

OBJECTIVE: Recent studies have shown that angiotensin II (Ang II) plays a critical role in the pathogenesis and progression of hypertensive kidney disease. However, the signaling mechanisms are poorly understood. In this study, we investigated the role of CXCR6 in Ang II-induced renal injury and fibrosis. APPROACH AND RESULTS: Wild-type and CXCR6-green fluorescent protein (GFP) knockin mice were treated with Ang II via subcutaneous osmotic minipumps at 1500 ng/kg per minute after unilateral nephrectomy for ≤ 4 weeks. Wild-type and CXCR6-GFP knockin mice had virtually identical blood pressure at baseline. Ang II treatment led to an increase in blood pressure that was similar between wild-type and CXCR6-GFP knockin mice. CXCR6-GFP knockin mice were protected from Ang II-induced renal dysfunction, proteinuria, and fibrosis. CXCR6-GFP knockin mice accumulated fewer bone marrow-derived fibroblasts and myofibroblasts and produced less extracellular matrix protein in the kidneys after Ang II treatment. Furthermore, CXCR6-GFP knockin mice exhibited fewer F4/80(+) macrophages and CD3(+) T cells and expressed less proinflammatory cytokines in the kidneys after Ang II treatment. Finally, wild-type mice engrafted with CXCR6(-/-) bone marrow cells displayed fewer bone marrow-derived fibroblasts, macrophages, and T cells in the kidney after Ang II treatment when compared with wild-type mice engrafted with CXCR6(+/+) bone marrow cells. CONCLUSIONS: Our results indicate that CXCR6 plays a pivotal role in the development of Ang II-induced renal injury and fibrosis through regulation of macrophage and T-cell infiltration and bone marrow-derived fibroblast accumulation.


Assuntos
Angiotensina II , Proteínas de Fluorescência Verde/metabolismo , Hipertensão/metabolismo , Nefropatias/metabolismo , Rim/metabolismo , Receptores CXCR/metabolismo , Albuminúria/etiologia , Albuminúria/metabolismo , Albuminúria/prevenção & controle , Animais , Pressão Sanguínea , Transplante de Medula Óssea , Citocinas/metabolismo , Modelos Animais de Doenças , Fibrose , Proteínas de Fluorescência Verde/genética , Hipertensão/induzido quimicamente , Hipertensão/genética , Hipertensão/patologia , Hipertensão/fisiopatologia , Mediadores da Inflamação/metabolismo , Rim/patologia , Nefropatias/etiologia , Nefropatias/genética , Nefropatias/patologia , Nefropatias/fisiopatologia , Nefropatias/prevenção & controle , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Miofibroblastos/metabolismo , Receptores CXCR/genética , Receptores CXCR6 , Transdução de Sinais , Linfócitos T/metabolismo , Fatores de Tempo
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