RESUMO
BACKGROUND: Reduced exercise capacity is a prognostic indicator of adverse outcomes in patients with acute myocardial infarction (AMI). However, few studies have evaluated the effectiveness of comprehensive cardiac rehabilitation (CR) in this population. This study aimed to clarify the efficacy of comprehensive CR in patients with AMI and reduced exercise capacity. METHODSâANDâRESULTS: This cohort study included 610 patients with AMI who underwent percutaneous coronary intervention. Major adverse cardiovascular events (MACE) were compared between patients who participated in comprehensive outpatient CR for 150 days (CR group; n=430) and those who did not (non-CR group; n=180). During the mean (±SD) follow-up period of 6.1±4.0 years, the CR group exhibited a lower incidence of MACE (log-rank P=0.002). Multivariable analysis revealed that Killip classification, diuretics at discharge, and participation in comprehensive CR were independently associated with MACE. The CR group was further divided into 2 groups, namely reduced exercise capacity (% predicted peak VÌO2<80%; n=241) and preserved exercise capacity (≥80%; n=147), based on the initial cardiopulmonary exercise test. Despite distinct exercise capacities, the incidence of MACE was comparable and physical parameters improved similarly after comprehensive CR in both groups. CONCLUSIONS: Comprehensive CR in patients with AMI effectively reduced the incidence of MACE regardless of initial exercise capacity. Cardiologists should actively encourage patients with low exercise capacity to participate in comprehensive CR.
Assuntos
Reabilitação Cardíaca , Tolerância ao Exercício , Infarto do Miocárdio , Intervenção Coronária Percutânea , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Infarto do Miocárdio/reabilitação , Infarto do Miocárdio/fisiopatologia , Infarto do Miocárdio/mortalidade , Reabilitação Cardíaca/métodos , Idoso , Resultado do Tratamento , Teste de Esforço , Estudos RetrospectivosRESUMO
Although there are many prognostic models for patients in the terminal phase of solid tumours, a reliable prognostic scoring system in patients in the terminal phase of haematological malignancies (HM) has not been established. We retrospectively evaluated 180 patients in the terminal phase of HM who were receiving home medical care (HMC). Multivariate analyses revealed that clinician's estimate, consciousness, loss of appetite, dyspnoea, neutrophil count, lymphocyte count, and lactate dehydrogenase were associated with overall survival (OS). Based on this result, we developed a novel prognostic scoring system, the Japan palliative haematological oncology prognostic estimates, in which four risk groups were shown to clearly differ in survival (p < 0.001): a low-risk group (n = 41, median OS of 434 days), an intermediate-low-risk group (n = 80, median OS of 112 days), an intermediate-high-risk group (n = 38, median OS of 31.5 days), and a high-risk group (n = 21, median OS of 10 days). This is the first investigation of prognostic factors that influence the OS of patients in the terminal phase of HM who are receiving HMC. Providing patients with reliable information about their prognosis is important for them to consider how to spend their remaining life.
Assuntos
Neoplasias Hematológicas , Neoplasias , Humanos , Prognóstico , Estudos Retrospectivos , Neoplasias Hematológicas/terapia , Fatores de RiscoRESUMO
Home care for patients with hematological diseases is often difficult to coordinate due to the challenges associated with continuous provision of supportive therapies, such as blood transfusions. On the other hand, home care needs of patients with hematological diseases are not clear. In this study, we conducted a questionnaire survey of patients with hematological diseases under home care. Responses were obtained from 605 patients with hematological diseases. Regarding home care, their primary expectation was a reduction in the physical burden caused by hospital visits, while their primary concern was emergency care due to a sudden change in their conditions. More than 90% of the patients stated that they wished to be seen by hematology specialists. In terms of blood transfusions, 53.5% wished to continue receiving a red blood cell transfusion and 53.9% a platelet transfusion at home. Furthermore, 70.9% of the patients stated that palliative chemotherapy was also needed in home care. With respect to emergency care, the highest percentage of patients(56.5%)wanted their home care doctors to treat them first and, if needed, contact their attending doctors at the hospital. This suggests the possibility that "the two-attending doctor system,"a concept that has gained importance in recent years, may also be effective in home care for hematological diseases.
Assuntos
Doenças Hematológicas , Serviços de Assistência Domiciliar , Transfusão de Sangue , Humanos , Transfusão de Plaquetas , Inquéritos e QuestionáriosRESUMO
The relationship between glycemic control and outcome in patients with heart failure (HF) remains contentious. A recent study showed that patients with HF with mid-range ejection fraction (HFmrEF) more frequently had comorbid diabetes relative to other patients. Herein, we examined the association between glycosylated hemoglobin (HbA1c) and in-hospital mortality in acute HF patients with reduced, mid-range, and preserved EF. A multicenter retrospective study was conducted on 5205 consecutive patients with acute HF. Potential risk factors for in-hospital mortality were selected by univariate analyses; then, multivariate Cox regression analysis with backward stepwise selection was performed to identify significant factors. Kaplan-Meier survival curves and log-rank testing were used to compare in-hospital mortality between groups. Across the study cohort, 44% (2288 patients) had reduced EF, 20% had mid-range EF, and 36% had preserved EF. The overall in-hospital mortality rate was 4.6%, with no significant differences among the HF patients with reduced, mid-range, and preserved EF groups. For patients with HFmrEF, higher HbA1c level was a significant risk factor for in-hospital mortality (hazard ratio 1.387; 95% confidence interval 1.014-1.899; P = 0.041). In contrast, HbA1c was not an independent risk factor for in-hospital mortality in HF patients with preserved or reduced EF. In conclusion, HbA1c is an independent risk factor for in-hospital mortality in acute HF patients with mid-range EF, but not in those with preserved or reduced EF. Elucidation of the pathophysiological mechanisms behind these findings could facilitate the development of more effective individualized therapies for acute HF.
Assuntos
Glicemia/metabolismo , Diabetes Mellitus/epidemiologia , Hemoglobinas Glicadas/metabolismo , Insuficiência Cardíaca/sangue , Volume Sistólico/fisiologia , Doença Aguda , Idoso , Causas de Morte/tendências , Comorbidade , Diabetes Mellitus/sangue , Feminino , Seguimentos , Índice Glicêmico , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/mortalidade , Mortalidade Hospitalar/tendências , Humanos , Japão/epidemiologia , Masculino , Estudos Retrospectivos , Fatores de RiscoRESUMO
RATIONALE: Hypoxia favors stem cell quiescence, whereas normoxia is required for stem cell activation, but whether cardiac stem cell (CSC) function is regulated by the hypoxic/normoxic state of the cell is currently unknown. OBJECTIVE: A balance between hypoxic and normoxic CSCs may be present in the young heart, although this homeostatic control may be disrupted with aging. Defects in tissue oxygenation occur in the old myocardium, and this phenomenon may expand the pool of hypoxic CSCs, which are no longer involved in myocyte renewal. METHODS AND RESULTS: Here, we show that the senescent heart is characterized by an increased number of quiescent CSCs with intact telomeres that cannot re-enter the cell cycle and form a differentiated progeny. Conversely, myocyte replacement is controlled only by frequently dividing CSCs with shortened telomeres; these CSCs generate a myocyte population that is chronologically young but phenotypically old. Telomere dysfunction dictates their actual age and mechanical behavior. However, the residual subset of quiescent young CSCs can be stimulated in situ by stem cell factor reversing the aging myopathy. CONCLUSIONS: Our findings support the notion that strategies targeting CSC activation and growth interfere with the manifestations of myocardial aging in an animal model. Although caution has to be exercised in the translation of animal studies to human beings, our data strongly suggest that a pool of functionally competent CSCs persists in the senescent heart and that this stem cell compartment can promote myocyte regeneration effectively, partly correcting the aging myopathy.
Assuntos
Envelhecimento/efeitos dos fármacos , Cardiomiopatias/metabolismo , Hipóxia/metabolismo , Mioblastos Cardíacos/metabolismo , Proteínas Proto-Oncogênicas c-kit/metabolismo , Fator de Células-Tronco/farmacologia , Nicho de Células-Tronco , Envelhecimento/metabolismo , Animais , Cardiomiopatias/tratamento farmacológico , Cardiomiopatias/patologia , Ciclo Celular , Linhagem da Célula , Proliferação de Células , Senescência Celular/efeitos dos fármacos , Hipóxia/patologia , Camundongos , Camundongos Endogâmicos C57BL , Mioblastos Cardíacos/efeitos dos fármacos , Mioblastos Cardíacos/fisiologia , Miocárdio/metabolismo , Miocárdio/patologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/fisiologia , Fator de Células-Tronco/uso terapêutico , Homeostase do TelômeroRESUMO
RATIONALE: Multiple progenitors derived from the heart and bone marrow (BM) have been used for cardiac repair. Despite this, not much is known about the molecular identity and relationship among these progenitors. To develop a robust stem cell therapy for the heart, it is critical to understand the molecular identity of the multiple cardiogenic progenitor cells. OBJECTIVE: This study is the first report of high-throughput transcriptional profiling of cardiogenic progenitor cells carried out on an identical platform. METHOD AND RESULTS: Microarray-based transcriptional profiling was carried out for 3 cardiac (ckit(+), Sca1(+), and side population) and 2 BM (ckit(+) and mesenchymal stem cell) progenitors, obtained from age- and sex-matched wild-type C57BL/6 mice. Analysis indicated that cardiac-derived ckit(+) population was very distinct from Sca1(+) and side population cells in the downregulation of genes encoding for cell-cell and cell-matrix adhesion proteins, and in the upregulation of developmental genes. Significant enrichment of transcripts involved in DNA replication and repair was observed in BM-derived progenitors. The BM ckit(+) cells seemed to have the least correlation with the other progenitors, with enrichment of immature neutrophil-specific molecules. CONCLUSIONS: Our study indicates that cardiac ckit(+) cells represent the most primitive population in the rodent heart. Primitive cells of cardiac versus BM origin differ significantly with respect to stemness and cardiac lineage-specific genes, and molecules involved in DNA replication and repair. The detailed molecular profile of progenitors reported here will serve as a useful reference to determine the molecular identity of progenitors used in future preclinical and clinical studies.
Assuntos
Células da Medula Óssea/metabolismo , Diferenciação Celular , Linhagem da Célula , Células-Tronco Mesenquimais/metabolismo , Miócitos Cardíacos/metabolismo , Células-Tronco/metabolismo , Animais , Antígenos Ly/metabolismo , Biomarcadores/metabolismo , Adesão Celular/genética , Comunicação Celular/genética , Diferenciação Celular/genética , Linhagem da Célula/genética , Células Cultivadas , Reparo do DNA/genética , Replicação do DNA/genética , Citometria de Fluxo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Ensaios de Triagem em Larga Escala , Separação Imunomagnética , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fenótipo , Proteínas Proto-Oncogênicas c-kit/metabolismo , RNA Mensageiro/metabolismo , Transdução de Sinais/genéticaRESUMO
A 56-year-old man was diagnosed with immunoglobulin (Ig) A-κ multiple myeloma in July 2007. After three courses of vincristine, adriamycin, and dexamethasone (VAD) chemotherapy, autologous peripheral blood stem cell transplantation was performed and achieved a very good partial response. In February 2010, an increase in the M-protein concentration and plasmacytoma in the L3/4 lumbar vertebrae were observed, and radiation treatment was performed. This was followed by administrations of bortezomib, lenalidomide, and thalidomide, none of which achieved a good response. In November 2011, the patient presented with obstructive jaundice, and imaging tests revealed tumorous lesions in the lower bile duct region and bilateral kidneys. Plasmacytoma was diagnosed from biopsy of the right renal mass. Radiotherapy to the common bile duct tumor resulted in jaundice amelioration, but the patient died despite subsequent treatment efforts. Autopsy revealed multiple extramedullary lesions in the abdominal cavity and in the region around the common bile duct. CD138 shedding was observed in the myeloma cells. We include a discussion of the literature on CD138 shedding and 38 reports of obstructive jaundice associated with extramedullary disease.
Assuntos
Icterícia Obstrutiva/etiologia , Mieloma Múltiplo/complicações , Biópsia , Evolução Fatal , Humanos , Icterícia Obstrutiva/terapia , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/patologia , Recidiva , Sindecana-1/imunologiaRESUMO
BACKGROUND: Little is known about the function of inositol 1,4,5-trisphosphate receptors (IP3Rs) in the adult heart experimentally. Moreover, whether these Ca(2+) release channels are present and play a critical role in human cardiomyocytes remains to be defined. IP3Rs may be activated after Gαq-protein-coupled receptor stimulation, affecting Ca(2+) cycling, enhancing myocyte performance, and potentially favoring an increase in the incidence of arrhythmias. METHODS AND RESULTS: IP3R function was determined in human left ventricular myocytes, and this analysis was integrated with assays in mouse myocytes to identify the mechanisms by which IP3Rs influence the electric and mechanical properties of the myocardium. We report that IP3Rs are expressed and operative in human left ventricular myocytes. After Gαq-protein-coupled receptor activation, Ca(2+) mobilized from the sarcoplasmic reticulum via IP3Rs contributes to the decrease in resting membrane potential, prolongation of the action potential, and occurrence of early afterdepolarizations. Ca(2+) transient amplitude and cell shortening are enhanced, and extrasystolic and dysregulated Ca(2+) elevations and contractions become apparent. These alterations in the electromechanical behavior of human cardiomyocytes are coupled with increased isometric twitch of the myocardium and arrhythmic events, suggesting that Gαq-protein-coupled receptor activation provides inotropic reserve, which is hampered by electric instability and contractile abnormalities. Additionally, our findings support the notion that increases in Ca(2+) load by IP3Rs promote Ca(2+) extrusion by forward-mode Na(+)/Ca(2+) exchange, an important mechanism of arrhythmic events. CONCLUSIONS: The Gαq-protein/coupled receptor/IP3R axis modulates the electromechanical properties of the human myocardium and its propensity to develop arrhythmias.
Assuntos
Potenciais de Ação/fisiologia , Sinalização do Cálcio/fisiologia , Insuficiência Cardíaca/fisiopatologia , Receptores de Inositol 1,4,5-Trifosfato/fisiologia , Miócitos Cardíacos/fisiologia , Adulto , Animais , Arritmias Cardíacas/fisiopatologia , Células Cultivadas , Feminino , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/fisiologia , Insuficiência Cardíaca/genética , Ventrículos do Coração/citologia , Humanos , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Contração Miocárdica/fisiologia , Miócitos Cardíacos/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/fisiologia , Retículo Sarcoplasmático/fisiologia , Transdução de Sinais/fisiologiaRESUMO
BACKGROUND: Although progenitor cells have been described in distinct anatomical regions of the lung, description of resident stem cells has remained elusive. METHODS: Surgical lung-tissue specimens were studied in situ to identify and characterize human lung stem cells. We defined their phenotype and functional properties in vitro and in vivo. RESULTS: Human lungs contain undifferentiated human lung stem cells nested in niches in the distal airways. These cells are self-renewing, clonogenic, and multipotent in vitro. After injection into damaged mouse lung in vivo, human lung stem cells form human bronchioles, alveoli, and pulmonary vessels integrated structurally and functionally with the damaged organ. The formation of a chimeric lung was confirmed by detection of human transcripts for epithelial and vascular genes. In addition, the self-renewal and long-term proliferation of human lung stem cells was shown in serial-transplantation assays. CONCLUSIONS: Human lungs contain identifiable stem cells. In animal models, these cells participate in tissue homeostasis and regeneration. They have the undemonstrated potential to promote tissue restoration in patients with lung disease. (Funded by the National Institutes of Health.).
Assuntos
Pulmão/citologia , Células-Tronco/fisiologia , Adulto , Animais , Células Clonais , Feminino , Humanos , Pulmão/embriologia , Pulmão/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Células-Tronco Pluripotentes , Proteínas Proto-Oncogênicas c-kit/análise , Regeneração , Transplante de Células-Tronco , Células-Tronco/químicaRESUMO
Whereas the demand on effective treatment options for chronic heart failure is dramatically increasing, the recent recognition of physiological and pathological myocyte turnover in the adult human heart provided a fundamental basis for the therapeutic regeneration. Divergent modalities were experimentally introduced to this field, and selected ones have been applied clinically; the history began with skeletal myoblasts and bone-marrow-derived cells, and lately mesenchymal stem/stromal cells and resident cardiac cells joined the repertoire. Among them, autologous transplantation of c-kit-positive cardiac stem cells in patients with chronic ventricular dysfunction resulted in an outstanding outcome with long-lasting effects without increasing major adverse events. To further optimize currently available approaches, we have to consider multiple factors, such as the targeting disease, the cell population and number to be administered, and the timing and the route of cell delivery. Exploration of the consequence of the previous clinical trials would allow us to envision an ideal cellular therapy for various cardiovascular disorders.
Assuntos
Terapia Baseada em Transplante de Células e Tecidos/métodos , Insuficiência Cardíaca/terapia , Miócitos Cardíacos/transplante , Regeneração/fisiologia , Transplante de Células-Tronco , Células-Tronco/fisiologia , Adulto , HumanosRESUMO
RATIONALE: Embryonic and fetal myocardial growth is characterized by a dramatic increase in myocyte number, but whether the expansion of the myocyte compartment is dictated by activation and commitment of resident cardiac stem cells (CSCs), division of immature myocytes or both is currently unknown. OBJECTIVE: In this study, we tested whether prenatal cardiac development is controlled by activation and differentiation of CSCs and whether division of c-kit-positive CSCs in the mouse heart is triggered by spontaneous Ca(2+) oscillations. METHODS AND RESULTS: We report that embryonic-fetal c-kit-positive CSCs are self-renewing, clonogenic and multipotent in vitro and in vivo. The growth and commitment of c-kit-positive CSCs is responsible for the generation of the myocyte progeny of the developing heart. The close correspondence between values computed by mathematical modeling and direct measurements of myocyte number at E9, E14, E19 and 1 day after birth strongly suggests that the organogenesis of the embryonic heart is dependent on a hierarchical model of cell differentiation regulated by resident CSCs. The growth promoting effects of c-kit-positive CSCs are triggered by spontaneous oscillations in intracellular Ca(2+), mediated by IP3 receptor activation, which condition asymmetrical stem cell division and myocyte lineage specification. CONCLUSIONS: Myocyte formation derived from CSC differentiation is the major determinant of cardiac growth during development. Division of c-kit-positive CSCs in the mouse is promoted by spontaneous Ca(2+) spikes, which dictate the pattern of stem cell replication and the generation of a myocyte progeny at all phases of prenatal life and up to one day after birth.
Assuntos
Diferenciação Celular/fisiologia , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Coração/embriologia , Miócitos Cardíacos/citologia , Miócitos Cardíacos/fisiologia , Proteínas Proto-Oncogênicas c-kit/metabolismo , Animais , Cálcio/metabolismo , Sinalização do Cálcio/fisiologia , Células Cultivadas , Técnicas de Cultura Embrionária , Receptores de Inositol 1,4,5-Trifosfato/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Animais , Modelos Teóricos , Organogênese/fisiologia , Proteínas Proto-Oncogênicas c-kit/genéticaRESUMO
RATIONALE: According to the immortal DNA strand hypothesis, dividing stem cells selectively segregate chromosomes carrying the old template DNA, opposing accumulation of mutations resulting from nonrepaired replication errors and attenuating telomere shortening. OBJECTIVE: Based on the premise of the immortal DNA strand hypothesis, we propose that stem cells retaining the old DNA would represent the most powerful cells for myocardial regeneration. METHODS AND RESULTS: Division of human cardiac stem cells (hCSCs) by nonrandom and random segregation of chromatids was documented by clonal assay of bromodeoxyuridine-tagged hCSCs. Additionally, their growth properties were determined by a series of in vitro and in vivo studies. We report that a small class of hCSCs retain during replication the mother DNA and generate 2 daughter cells, which carry the old and new DNA, respectively. hCSCs with immortal DNA form a pool of nonsenescent cells with longer telomeres and higher proliferative capacity. The self-renewal and long-term repopulating ability of these cells was shown in serial-transplantation assays in the infarcted heart; these cells created a chimeric organ, composed of spared rat and regenerated human cardiomyocytes and coronary vessels, leading to a remarkable restoration of cardiac structure and function. The documentation that hCSCs divide by asymmetrical and symmetrical chromatid segregation supports the view that the human heart is a self-renewing organ regulated by a compartment of resident hCSCs. CONCLUSIONS: The impressive recovery in ventricular hemodynamics and anatomy mediated by clonal hCSCs carrying the "mother" DNA underscores the clinical relevance of this stem cell class for the management of heart failure in humans.
Assuntos
Cromátides/fisiologia , Segregação de Cromossomos/fisiologia , Coração/fisiologia , Infarto do Miocárdio/terapia , Miocárdio/citologia , Regeneração/fisiologia , Transplante de Células-Tronco , Células-Tronco/citologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Bromodesoxiuridina , Proliferação de Células , Células Cultivadas , Criança , Pré-Escolar , Cromátides/ultraestrutura , DNA/fisiologia , Feminino , Humanos , Técnicas In Vitro , Lactente , Masculino , Pessoa de Meia-Idade , Modelos Animais , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Ratos , Ratos Endogâmicos F344 , Células-Tronco/fisiologia , Telômero/ultraestrutura , Adulto JovemRESUMO
The prenatal diagnosis of fetal heart disease potentially influences parental decision-making regarding pregnancy termination. Existing literature indicates that the severity, whether in complexity or lethality, significantly influences parental decisions concerning abortion. However, questions remain as to how fetal heart disease severity impacts parental decisions, given recent advancements in postsurgical outcomes. Therefore, we investigated risk factors associated with parents' decision-making regarding abortion following a prenatal diagnosis of fetal heart disease. Our analysis included 73 (terminated: n = 37; continued: n = 36) pregnancies with a fetal heart disease diagnosed before 22 weeks of gestation. Increased gestational age at diagnosis reduced the likelihood of parents' decision on termination (Model 1: adjusted odds ratio, 0.94; 95% confidence interval 0.89-0.99; Model 2: 0.95 0.90-0.997). Critical disease (5.25; 1.09-25.19) and concurrent extracardiac or genetic abnormalities (Model 1: 4.19, 1.21-14.53; Model 2: 5.47, 1.50-19.96) increased the likelihood of choosing abortion. Notably, complex disease did not significantly influence parental decisions (0.56; 0.14-2.20). These results suggest that parental decision-making regarding abortion may be influenced by earlier gestational age at diagnosis, the lethality of heart disease, and extracardiac or genetic abnormalities, but not its complexity if prenatal diagnosis and parental counseling are provided at a cardiovascular-specialized facility.
Assuntos
Aborto Induzido , Tomada de Decisões , Pais , Diagnóstico Pré-Natal , Humanos , Feminino , Gravidez , Aborto Induzido/psicologia , Adulto , Pais/psicologia , Idade Gestacional , Cardiopatias Congênitas , Cardiopatias , Fatores de Risco , Doenças Fetais , Masculino , Índice de Gravidade de DoençaRESUMO
BACKGROUND: Two opposite views of cardiac growth are currently held; one views the heart as a static organ characterized by a large number of cardiomyocytes that are present at birth and live as long as the organism, and the other views the heart a highly plastic organ in which the myocyte compartment is restored several times during the course of life. METHODS AND RESULTS: The average age of cardiomyocytes, vascular endothelial cells (ECs), and fibroblasts and their turnover rates were measured by retrospective (14)C birth dating of cells in 19 normal hearts 2 to 78 years of age and in 17 explanted failing hearts 22 to 70 years of age. We report that the human heart is characterized by a significant turnover of ventricular myocytes, ECs, and fibroblasts, physiologically and pathologically. Myocyte, EC, and fibroblast renewal is very high shortly after birth, decreases during postnatal maturation, remains relatively constant in the adult organ, and increases dramatically with age. From 20 to 78 years of age, the adult human heart entirely replaces its myocyte, EC, and fibroblast compartment ≈8, ≈6, and ≈8 times, respectively. Myocyte, EC, and fibroblast regeneration is further enhanced with chronic heart failure. CONCLUSIONS: The human heart is a highly dynamic organ that retains a remarkable degree of plasticity throughout life and in the presence of chronic heart failure. However, the ability to regenerate cardiomyocytes, vascular ECs, and fibroblasts cannot prevent the manifestations of myocardial aging or oppose the negative effects of ischemic and idiopathic dilated cardiomyopathy.
Assuntos
Insuficiência Cardíaca/fisiopatologia , Desenvolvimento Muscular/fisiologia , Miócitos Cardíacos/fisiologia , Adolescente , Adulto , Idoso , Envelhecimento , Criança , Pré-Escolar , Células Endoteliais/fisiologia , Fibroblastos/fisiologia , Coração/fisiologia , Humanos , Pessoa de Meia-Idade , Miócitos Cardíacos/citologia , Regeneração , Doadores de Tecidos , Adulto JovemRESUMO
RATIONALE: Understanding the mechanisms that regulate trafficking of human cardiac stem cells (hCSCs) may lead to development of new therapeutic approaches for the failing heart. OBJECTIVE: We tested whether the motility of hCSCs in immunosuppressed infarcted animals is controlled by the guidance system that involves the interaction of Eph receptors with ephrin ligands. METHODS AND RESULTS: Within the cardiac niches, cardiomyocytes expressed preferentially the ephrin A1 ligand, whereas hCSCs possessed the EphA2 receptor. Treatment of hCSCs with ephrin A1 resulted in the rapid internalization of the ephrin A1-EphA2 complex, posttranslational modifications of Src kinases, and morphological changes consistent with the acquisition of a motile cell phenotype. Ephrin A1 enhanced the motility of hCSCs in vitro, and their migration in vivo following acute myocardial infarction. At 2 weeks after infarction, the volume of the regenerated myocardium was 2-fold larger in animals injected with ephrin A1-activated hCSCs than in animals receiving control hCSCs; this difference was dictated by a greater number of newly formed cardiomyocytes and coronary vessels. The increased recovery in myocardial mass with ephrin A1-treated hCSCs was characterized by further restoration of cardiac function and by a reduction in arrhythmic events. CONCLUSIONS: Ephrin A1 promotes the motility of EphA2-positive hCSCs, facilitates their migration to the area of damage, and enhances cardiac repair. Thus, in situ stimulation of resident hCSCs with ephrin A1 or their ex vivo activation before myocardial delivery improves cell targeting to sites of injury, possibly providing a novel strategy for the management of the diseased heart.
Assuntos
Efrina-A1/genética , Efrina-A2/genética , Células-Tronco Hematopoéticas/citologia , Infarto do Miocárdio/fisiopatologia , Miócitos Cardíacos/citologia , Animais , Adesão Celular/fisiologia , Membrana Celular/metabolismo , Movimento Celular/fisiologia , Citoplasma/metabolismo , Efrina-A1/metabolismo , Efrina-A2/metabolismo , Expressão Gênica/fisiologia , Proteínas de Fluorescência Verde/genética , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Infarto do Miocárdio/patologia , Infarto do Miocárdio/terapia , Ratos , Ratos Endogâmicos F344 , Taquicardia Ventricular/patologia , Taquicardia Ventricular/fisiopatologia , Taquicardia Ventricular/terapiaRESUMO
RATIONALE: Two categories of cardiac stem cells (CSCs) with predominantly myogenic (mCSC) and vasculogenic (vCSC) properties have been characterized in the human heart. However, it is unknown whether functionally competent CSCs of both classes are present in the myocardium of patients affected by end-stage cardiac failure, and whether these cells can be harvested from relatively small myocardial samples. OBJECTIVE: To establish whether a clinically relevant number of mCSCs and vCSCs can be isolated and expanded from endomyocardial biopsies of patients undergoing cardiac transplantation or left ventricular assist device implantation. METHODS AND RESULTS: Endomyocardial biopsies were collected with a bioptome from the right side of the septum of explanted hearts or the apical LV core at the time of left ventricular assist device implantation. Two to 5 biopsies from each patient were enzymatically dissociated, and, after expansion, cells were sorted for c-kit (mCSCs) or c-kit and KDR (vCSCs) and characterized. mCSCs and vCSCs constituted 97% and 3% of the c-kit population, respectively. Population doubling time averaged 27 hours in mCSCs and vCSCs; 5×10(6) mCSCs and vCSCs were obtained in 28 and 41 days, respectively. Both CSC classes possessed significant growth reserve as documented by high telomerase activity and relatively long telomeres. mCSCs formed mostly cardiomyocytes, and vCSCs endothelial and smooth muscle cells. CONCLUSIONS: The growth properties of mCSCs and vCSCs isolated from endomyocardial biopsies from patients with advanced heart failure were comparable to those obtained previously from larger myocardial samples of patients undergoing elective cardiac surgery.
Assuntos
Células-Tronco Adultas/patologia , Células-Tronco Adultas/fisiologia , Cardiomiopatias/patologia , Miocárdio/patologia , Adulto , Idoso , Biópsia , Cardiomiopatias/fisiopatologia , Diferenciação Celular/fisiologia , Proliferação de Células , Células Cultivadas , Feminino , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Telômero/patologiaRESUMO
RATIONALE: Age and coronary artery disease may negatively affect the function of human cardiac stem cells (hCSCs) and their potential therapeutic efficacy for autologous cell transplantation in the failing heart. OBJECTIVE: Insulin-like growth factor (IGF)-1, IGF-2, and angiotensin II (Ang II), as well as their receptors, IGF-1R, IGF-2R, and AT1R, were characterized in c-kit(+) hCSCs to establish whether these systems would allow us to separate hCSC classes with different growth reserve in the aging and diseased myocardium. METHODS AND RESULTS: C-kit(+) hCSCs were collected from myocardial samples obtained from 24 patients, 48 to 86 years of age, undergoing elective cardiac surgery for coronary artery disease. The expression of IGF-1R in hCSCs recognized a young cell phenotype defined by long telomeres, high telomerase activity, enhanced cell proliferation, and attenuated apoptosis. In addition to IGF-1, IGF-1R(+) hCSCs secreted IGF-2 that promoted myocyte differentiation. Conversely, the presence of IGF-2R and AT1R, in the absence of IGF-1R, identified senescent hCSCs with impaired growth reserve and increased susceptibility to apoptosis. The ability of IGF-1R(+) hCSCs to regenerate infarcted myocardium was then compared with that of unselected c-kit(+) hCSCs. IGF-1R(+) hCSCs improved cardiomyogenesis and vasculogenesis. Pretreatment of IGF-1R(+) hCSCs with IGF-2 resulted in the formation of more mature myocytes and superior recovery of ventricular structure. CONCLUSIONS: hCSCs expressing only IGF-1R synthesize both IGF-1 and IGF-2, which are potent modulators of stem cell replication, commitment to the myocyte lineage, and myocyte differentiation, which points to this hCSC subset as the ideal candidate cell for the management of human heart failure.
Assuntos
Doença da Artéria Coronariana/metabolismo , Infarto do Miocárdio/metabolismo , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Receptor IGF Tipo 1/metabolismo , Regeneração , Células-Tronco/metabolismo , Angiotensina II/metabolismo , Diferenciação Celular , Doença da Artéria Coronariana/patologia , Doença da Artéria Coronariana/terapia , Feminino , Humanos , Fator de Crescimento Insulin-Like I/biossíntese , Fator de Crescimento Insulin-Like II/metabolismo , Masculino , Infarto do Miocárdio/patologia , Infarto do Miocárdio/terapia , Miocárdio/patologia , Miócitos Cardíacos/patologia , Receptor IGF Tipo 2/metabolismo , Transplante de Células-Tronco , Células-Tronco/patologia , Transplante AutólogoRESUMO
We report a 53-year-old male with POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) syndrome who relapsed after autologous peripheral stem cell transplantation (ASCT), but responded extremely well to lenalidomide (LEN) plus low dose dexamethasone (Ld) therapy. The patient had been diagnosed with POEMS syndrome in November 2006, and underwent ASCT in February 2007. In July 2011, he developed respiratory distress, generalized edema, and massive bilateral pleural effusion. Plasma vascular endothelial growth factor (VEGF) and M protein were increased, strongly indicating a relapse. Ld therapy was remarkably effective for these symptoms, resulting in complete remission with M-protein becoming undetectable by immunofixation. Since completing 11 courses of therapy with an every 4 weeks regimen, he has remained in clinical remission. The patient's activities of daily living have also markedly improved from total physical incapacity to being able to stand with slight assistance. LEN is associated with a lower incidence of peripheral neuropathy than other new drugs. Although LEN has occasionally been given to patients with POEMS syndrome in recent years, there are still few reports on its use for patients with recurrent disease after ASCT. Our successful management of this patient suggests that Ld therapy is not only relatively safe but also a promising option for POEMS syndrome relapsing after ASCT.
Assuntos
Dexametasona/uso terapêutico , Síndrome POEMS/terapia , Transplante de Células-Tronco de Sangue Periférico , Talidomida/análogos & derivados , Dexametasona/administração & dosagem , Humanos , Lenalidomida , Masculino , Pessoa de Meia-Idade , Síndrome POEMS/diagnóstico , Transplante de Células-Tronco de Sangue Periférico/métodos , Prevenção Secundária , Talidomida/uso terapêutico , Transplante Autólogo/métodos , Resultado do TratamentoRESUMO
BACKGROUND: Cardiac stem cells (CSCs) delivered to the infarcted heart generate a large number of small fetal-neonatal cardiomyocytes that fail to acquire the differentiated phenotype. However, the interaction of CSCs with postmitotic myocytes results in the formation of cells with adult characteristics. METHODS AND RESULTS: On the basis of results of in vitro and in vivo assays, we report that the commitment of human CSCs (hCSCs) to the myocyte lineage and the generation of mature working cardiomyocytes are influenced by microRNA-499 (miR-499), which is barely detectable in hCSCs but is highly expressed in postmitotic human cardiomyocytes. miR-499 traverses gap junction channels and translocates to structurally coupled hCSCs favoring their differentiation into functionally competent cells. Expression of miR-499 in hCSCs represses the miR-499 target genes Sox6 and Rod1, enhancing cardiomyogenesis in vitro and after infarction in vivo. Although cardiac repair was detected in all cell-treated infarcted hearts, the aggregate volume of the regenerated myocyte mass and myocyte cell volume were greater in animals injected with hCSCs overexpressing miR-499. Treatment with hCSCs resulted in an improvement in ventricular function, consisting of a better preservation of developed pressure and positive and negative dP/dt after infarction. An additional positive effect on cardiac performance occurred with miR-499, pointing to enhanced myocyte differentiation/hypertrophy as the mechanism by which miR-499 potentiated the restoration of myocardial mass and function in the infarcted heart. CONCLUSIONS: The recognition that miR-499 promotes the differentiation of hCSCs into mechanically integrated cardiomyocytes has important clinical implications for the treatment of human heart failure.
Assuntos
Células-Tronco Adultas/citologia , MicroRNAs/fisiologia , Infarto do Miocárdio/terapia , Miócitos Cardíacos/citologia , Transplante de Células-Tronco , Células-Tronco Adultas/fisiologia , Animais , Diferenciação Celular/fisiologia , Divisão Celular/fisiologia , Células Cultivadas , Técnicas de Cocultura , Modelos Animais de Doenças , Junções Comunicantes/fisiologia , Expressão Gênica/fisiologia , Humanos , Infarto do Miocárdio/patologia , Miócitos Cardíacos/fisiologia , Proteína de Ligação a Regiões Ricas em Polipirimidinas , Proteínas de Ligação a RNA/genética , Ratos , Regeneração/fisiologia , Fatores de Transcrição SOXD/genéticaRESUMO
BACKGROUND: c-kit-positive, lineage-negative cardiac stem cells (CSCs) improve post-infarction left ventricular (LV) dysfunction when administered to animals. We undertook a phase 1 trial (Stem Cell Infusion in Patients with Ischemic cardiOmyopathy [SCIPIO]) of autologous CSCs for the treatment of heart failure resulting from ischaemic heart disease. METHODS: In stage A of the SCIPIO trial, patients with post-infarction LV dysfunction (ejection fraction [EF] ≤40%) before coronary artery bypass grafting were consecutively enrolled in the treatment and control groups. In stage B, patients were randomly assigned to the treatment or control group in a 2:3 ratio by use of a computer-generated block randomisation scheme. 1 million autologous CSCs were administered by intracoronary infusion at a mean of 113 days (SE 4) after surgery; controls were not given any treatment. Although the study was open label, the echocardiographic analyses were masked to group assignment. The primary endpoint was short-term safety of CSCs and the secondary endpoint was efficacy. A per-protocol analysis was used. This study is registered with ClinicalTrials.gov, number NCT00474461. FINDINGS: This study is still in progress. 16 patients were assigned to the treatment group and seven to the control group; no CSC-related adverse effects were reported. In 14 CSC-treated patients who were analysed, LVEF increased from 30·3% (SE 1·9) before CSC infusion to 38·5% (2·8) at 4 months after infusion (p=0·001). By contrast, in seven control patients, during the corresponding time interval, LVEF did not change (30·1% [2·4] at 4 months after CABG vs 30·2% [2·5] at 8 months after CABG). Importantly, the salubrious effects of CSCs were even more pronounced at 1 year in eight patients (eg, LVEF increased by 12·3 ejection fraction units [2·1] vs baseline, p=0·0007). In the seven treated patients in whom cardiac MRI could be done, infarct size decreased from 32·6 g (6·3) by 7·8 g (1·7; 24%) at 4 months (p=0·004) and 9·8 g (3·5; 30%) at 1 year (p=0·04). INTERPRETATION: These initial results in patients are very encouraging. They suggest that intracoronary infusion of autologous CSCs is effective in improving LV systolic function and reducing infarct size in patients with heart failure after myocardial infarction, and warrant further, larger, phase 2 studies. FUNDING: University of Louisville Research Foundation and National Institutes of Health.