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1.
Contemp Clin Trials ; 62: 159-167, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28887069

RESUMO

BACKGROUND: Chronic Obstructive Pulmonary Disease (COPD) is a leading cause of hospitalizations. Interventional studies focusing on the hospital-to-home transition for COPD patients are few. In the BREATHE (Better Respiratory Education and Treatment Help Empower) study, we developed and tested a patient and family-centered transitional care program that helps prepare hospitalized COPD patients and their family caregivers to manage COPD at home. METHODS: In the study's initial phase, we co-developed the BREATHE transitional care program with COPD patients, family-caregivers, and stakeholders. The program offers tailored services to address individual patients' needs and priorities at the hospital and for 3months post discharge. We tested the program in a single-blinded RCT with 240 COPD patients who were randomized to receive the program or 'usual care'. Program participants were offered the opportunity to invite a family caregiver, if available, to enroll with them into the study. The primary outcomes were the combined number of COPD-related hospitalizations and Emergency Department (ED) visits per participant at 6months post discharge, and the change in health-related quality of life over the 6months study period. Other measures include 'all cause' hospitalizations and ED visits; patient activation; self-efficacy; and, self-care behaviors. DISCUSSION: Unlike 1month transitional care programs that focus on patients' post-acute care needs, the BREATHE program helps hospitalized COPD patients manage the post discharge period as well as prepare them for long term self-management of COPD. If proven effective, this program may offer a timely solution for hospitals in their attempts to reduce COPD rehospitalizations.


Assuntos
Serviço Hospitalar de Emergência/estatística & dados numéricos , Hospitalização/estatística & dados numéricos , Assistência Centrada no Paciente/organização & administração , Cuidado Transicional/organização & administração , Fatores Etários , Idoso , Serviços de Saúde Comunitária/organização & administração , Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Equipe de Assistência ao Paciente/organização & administração , Educação de Pacientes como Assunto/organização & administração , Projetos Piloto , Doença Pulmonar Obstrutiva Crônica/terapia , Qualidade de Vida , Projetos de Pesquisa , Autocuidado , Autoeficácia , Fatores Sexuais , Método Simples-Cego , Fatores Socioeconômicos
2.
J Mol Cell Cardiol ; 111: 40-50, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28782514

RESUMO

Exosomes have an evolving role in paracrine and autocrine signaling, which is enhanced because these lipid vesicles are quite stable and can deliver miRNA, DNA, protein and other molecules to cells throughout the body. Most cell types release exosomes, and exosomes are found in all biological fluids, making them accessible biomarkers. Significantly, exosomes can carry a biologically potent cargo, which can alter the phenotype of recipient cells. In the cardiovascular system exosomes have been primarily studied for their role in mediating the beneficial effects of mesenchymal stem cells after myocardial injury. Exosomes released by cardiac cells in disease states, such as myocardial ischemia, can potentially have important pathophysiologic effects on other cardiac cells as well as on distant organs.


Assuntos
Sistema Cardiovascular/metabolismo , Exossomos/metabolismo , Animais , Biomarcadores/metabolismo , Doenças Cardiovasculares/metabolismo , Humanos , Modelos Biológicos , Células-Tronco/metabolismo
3.
Cell Stress Chaperones ; 20(3): 527-35, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25716072

RESUMO

Extracellular (ex) HSP60 is increasingly recognized as an agent of cell injury. Previously, we reported that low endotoxin exHSP60 causes cardiac myocyte apoptosis. Our findings supported a role for Toll-like receptor (TLR) 4 in HSP60 mediated apoptosis. To further investigate the involvement of TLR4 in cardiac injury, we studied adult cardiac myocytes from C3H/HeJ (HeJ) mice, which have a mutant, nonfunctional TLR4, and compared the results with parallel studies using wild-type (WT) mice. Nuclear factor κB (NFκB) activation is an early step downstream of TLR4. NFκB was activated 1 h after treatment with HSP60 in WT, but not HeJ mouse myocytes. ExHSP60 caused apoptosis in cardiac myocytes from WT mice, but not in myocytes from the HeJ mutants. To further elucidate the importance of exHSP60 in cardiac myocyte injury, both WT and HeJ mutant isolated mouse adult cardiac myocytes were exposed to hypoxia/reoxygenation. Anti-HSP60 antibody treatment reduced apoptosis in the WT group, but had no effect on the HeJ mutant myocytes. Unexpectedly, necrosis was also decreased in the HeJ mutants. Necrosis after hypoxia/reoxygenation in WT cardiac myocytes was mediated in part by TLR2 and TLR4 through rapid activation of PKCα, followed by increased expression of Nox2, and this was ameliorated by blocking antibodies to TLR2/4. These studies provide further evidence that TLR4 mediates exHSP60-associated apoptosis and that exHSP60 has an important role in cardiac myocyte injury, both apoptotic and necrotic.


Assuntos
Apoptose , Chaperonina 60/fisiologia , Proteínas Mitocondriais/fisiologia , Miócitos Cardíacos/fisiologia , Receptor 4 Toll-Like/genética , Animais , Hipóxia Celular , Células Cultivadas , Camundongos Endogâmicos C3H , Necrose , Mutação Puntual , Receptor 4 Toll-Like/metabolismo
4.
Compr Physiol ; 6(1): 507-26, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26756641

RESUMO

Mitochondrial dynamics, fission and fusion, were first identified in yeast with investigation in heart cells beginning only in the last 5 to 7 years. In the ensuing time, it has become evident that these processes are not only required for healthy mitochondria, but also, that derangement of these processes contributes to disease. The fission and fusion proteins have a number of functions beyond the mitochondrial dynamics. Many of these functions are related to their membrane activities, such as apoptosis. However, other functions involve other areas of the mitochondria, such as OPA1's role in maintaining cristae structure and preventing cytochrome c leak, and its essential (at least a 10 kDa fragment of OPA1) role in mtDNA replication. In heart disease, changes in expression of these important proteins can have detrimental effects on mitochondrial and cellular function.


Assuntos
Insuficiência Cardíaca/metabolismo , Dinâmica Mitocondrial , Animais , Apoptose , Humanos , Mitocôndrias Musculares/metabolismo , Estresse Oxidativo
5.
Mol Cell Endocrinol ; 389(1-2): 31-9, 2014 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-24462775

RESUMO

Estrogen has a plethora of effects in the cardiovascular system. Studies of estrogen and the heart span human clinical trials and basic cell and molecular investigations. Greater understanding of cell and molecular responses to estrogens can provide further insights into the findings of clinical studies. Differences in expression and cellular/intracellular distribution of the two main receptors, estrogen receptor (ER) α and ß, are thought to account for the specificity and differences in responses to estrogen. Much remains to be learned in this area, but cellular distribution within the cardiovascular system is becoming clearer. Identification of GPER as a third ER has introduced further complexity to the system. 17ß-estradiol (E2), the most potent human estrogen, clearly has protective properties activating a signaling cascade leading to cellular protection and also influencing expression of the protective heat shock proteins (HSP). E2 protects the heart from ischemic injury in basic studies, but the picture is more involved in the whole organism and clinical studies. Here the complexity of E2's widespread effects comes into play and makes interpretation of findings more challenging. Estrogen loss occurs primarily with aging, but few studies have used aged models despite clear evidence of differences between the response to estrogen deficiency in adult and aged animals. Thus more work is needed focusing on the effects of aging vs. estrogen loss on the cardiovascular system.


Assuntos
Estrogênios/metabolismo , Coração/fisiologia , Fatores Etários , Animais , Ensaios Clínicos como Assunto , Feminino , Humanos , Miocárdio/metabolismo , Receptores de Estrogênio/metabolismo
6.
Am J Physiol Heart Circ Physiol ; 304(7): H954-65, 2013 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-23376832

RESUMO

Exosomes, which are 50- to 100-nm-diameter lipid vesicles, have been implicated in intercellular communication, including transmitting malignancy, and as a way for viral particles to evade detection while spreading to new cells. Previously, we demonstrated that adult cardiac myocytes release heat shock protein (HSP)60 in exosomes. Extracellular HSP60, when not in exosomes, causes cardiac myocyte apoptosis via the activation of Toll-like receptor 4. Thus, release of HSP60 from exosomes would be damaging to the surrounding cardiac myocytes. We hypothesized that 1) pathological changes in the environment, such as fever, change in pH, or ethanol consumption, would increase exosome permeability; 2) different exosome inducers would result in different exosomal protein content; 3) ethanol at "physiological" concentrations would cause exosome release; and 4) ROS production is an underlying mechanism of increased exosome production. We found the following: first, exosomes retained their protein cargo under different physiological/pathological conditions, based on Western blot analyses. Second, mass spectrometry demonstrated that the protein content of cardiac exosomes differed significantly from other types of exosomes in the literature and contained cytosolic, sarcomeric, and mitochondrial proteins. Third, ethanol did not affect exosome stability but greatly increased the production of exosomes by cardiac myocytes. Fourth, ethanol- and hypoxia/reoxygenation-derived exosomes had different protein content. Finally, ROS inhibition reduced exosome production but did not completely inhibit it. In conclusion, exosomal protein content is influenced by the cell source and stimulus for exosome formation. ROS stimulate exosome production. The functions of exosomes remain to be fully elucidated.


Assuntos
Chaperonina 60/análise , Exossomos/química , Miócitos Cardíacos/química , Proteoma/análise , Animais , Etanol/farmacologia , Exossomos/metabolismo , Exossomos/ultraestrutura , Hipóxia/metabolismo , Masculino , Proteínas Mitocondriais/análise , Miócitos Cardíacos/patologia , Estabilidade Proteica , Proteoma/efeitos dos fármacos , Proteômica , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/antagonistas & inibidores
7.
Pharmacol Ther ; 135(1): 54-70, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22484805

RESUMO

Estrogen is a potent steroid with pleiotropic effects, which have yet to be fully elucidated. Estrogen has both nuclear and non-nuclear effects. The rapid response to estrogen, which involves a membrane associated estrogen receptor(ER) and is protective, involves signaling through PI3K, Akt, and ERK 1/2. The nuclear response is much slower, as the ER-estrogen complex moves to the nucleus, where it functions as a transcription factor, both activating and repressing gene expression. Several different ERs regulate the specificity of response to estrogen, and appear to have specific effects in cardiac remodeling and the response to injury. However, much remains to be understood about the selectivity of these receptors and their specific effects on gene expression. Basic studies have demonstrated that estrogen treatment prevents apoptosis and necrosis of cardiac and endothelial cells. Estrogen also attenuates pathologic cardiac hypertrophy. Estrogen may have great benefit in aging as an anti-inflammatory agent. However, clinical investigations of estrogen have had mixed results, and not shown the clear-cut benefit of more basic investigations. This can be explained in part by differences in study design: in basic studies estrogen treatment was used immediately or shortly after ovariectomy, while in some key clinical trials, estrogen was given years after menopause. Further basic research into the underlying molecular mechanisms of estrogen's actions is essential to provide a better comprehension of the many properties of this powerful hormone.


Assuntos
Doenças Cardiovasculares/metabolismo , Sistema Cardiovascular/metabolismo , Estrogênios/metabolismo , Envelhecimento/metabolismo , Animais , Vasos Sanguíneos/metabolismo , Vasos Sanguíneos/fisiopatologia , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/fisiopatologia , Doenças Cardiovasculares/prevenção & controle , Sistema Cardiovascular/fisiopatologia , Terapia de Reposição de Estrogênios , Estrogênios/uso terapêutico , Humanos , Inflamação/metabolismo , Menopausa/metabolismo , Miocárdio/metabolismo , Receptores de Estrogênio/metabolismo , Transdução de Sinais
8.
Physiol Genomics ; 43(18): 1065-73, 2011 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-21750230

RESUMO

Despite an abundance of evidence to the contrary from animal studies, large clinical trials on humans have shown that estrogen administered to postmenopausal women increases the risk of cardiovascular disease. However, timing may be everything, as estrogen is often administered immediately after ovariectomy (Ovx) in animal studies, while estrogen administration in human studies occurred many years postmenopause. This study investigates the discrepancy by administering 17ß-estradiol (E2) in a slow-release capsule to Norway Brown rats both immediately following Ovx and 9 wk post-Ovx (Late), and studying differences in gene expression between these two groups compared with age-matched Ovx and sham-operated animals. Two different types of microarray were used to analyze the left ventricles from these groups: an Affymetrix array (n = 3/group) and an inflammatory cytokines and receptors PCR array (n = 4/group). Key genes were analyzed by Western blotting. Ovx without replacement led to an increase in caspase 3, caspase 9, calpain 2, matrix metalloproteinase (MMP)9, and TNF-α. Caspase 6, STAT3, and CD11b increased in the Late group, while tissue inhibitor of metalloproteinase 2, MMP14, and collagen I α1 were decreased. MADD and fibronectin were increased in both Ovx and Late. TNF-α and inducible nitric oxide synthase (iNOS) protein levels increased with Late replacement. Many of these changes were prevented by early E2 replacement. These findings suggest that increased expression of inflammatory genes, such as TNF-α and iNOS, may be involved in some of the deleterious effects of delayed E2 administration seen in human studies.


Assuntos
Envelhecimento/sangue , Terapia de Reposição de Estrogênios , Estrogênios/sangue , Estrogênios/uso terapêutico , Regulação da Expressão Gênica , Inflamação/tratamento farmacológico , Inflamação/genética , Miocárdio/metabolismo , Animais , Apoptose/genética , Western Blotting , Matriz Extracelular/genética , Feminino , Humanos , Modelos Biológicos , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase , Ratos , Ratos Endogâmicos BN , Transdução de Sinais/genética
9.
Congest Heart Fail ; 17(6): 257-61, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22848903

RESUMO

Mitochondria have been widely studied for their critical role in cellular metabolism, energy production, and cell death. New developments in research on mitochondria derived from studies in yeast have led to the discovery of entirely new mitochondrial processes that have implications for mitochondrial function in heart failure. Recent studies have identified that maintaining normal mitochondrial morphology and function depends on the dynamic balance of mitochondrial fusion and fission (division). Mitochondrial fusion and fission are constant ongoing processes, which are essential for the maintenance of normal mitochondrial function. Studies in heart failure have been limited but suggest a possible reduction in mitochondrial fusion. As mitochondrial fusion and fission have important links to apoptosis, a key mechanism of loss of cardiac myocytes in heart failure, there are many implications for both heart failure research and treatment.


Assuntos
Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Mitocôndrias Cardíacas/metabolismo , Mitocôndrias Cardíacas/patologia , Proteínas Mitocondriais/fisiologia , Apoptose , Respiração Celular/fisiologia , Insuficiência Cardíaca/terapia , Humanos
10.
Minerva Cardioangiol ; 58(2): 213-29, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20440251

RESUMO

Cardiac mitochondria are powerful organelles supplying energy to support the high adenosine triphosphate (ATP) consumption of the beating heart. The progression of HF (HF) is characterized by diminished energy metabolism, calcium mishandling, reactive oxygen species (ROS) generation and apoptotic cell death. Although the etiologies of HF are multifactoral, many of the changes of HF are associated with cardiac mitochondrial dysfunction either directly or indirectly. A number of studies have established the role of calcium mishandling and reduced ATP production in mitochondrial dysfunction in HF. More recent work has contributed to our understanding of the role of ROS and proapoptotic protein release by the mitochondria in HF. New interest has been generated in mitochondria by the relatively recent identification of the processes of fusion and fission, which are critical to the maintenance of healthy mitochondria. Fission and fusion also have significant roles in apoptosis. Other studies have shown that estrogen has important functions in the mitochondria, including regulation of mitochondrial gene expression. Aging alone contributes to the development of HF through multiple mechanisms. These new insights into HF have implications for our understanding of this important disease, and will be reviewed here.


Assuntos
Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/metabolismo , Mitocôndrias/metabolismo , Envelhecimento/metabolismo , Animais , Apoptose , Cálcio/metabolismo , Estrogênios/fisiologia , Humanos
11.
J Mol Cell Cardiol ; 48(2): 360-6, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19945465

RESUMO

Heart failure, a progressive, fatal disease of the heart muscle, is a state of chronic inflammation and injury. Heat shock protein (HSP) 72, a ubiquitous protective protein that is well-established as cardioprotective, is not increased in heart failure. In contrast, HSP60 levels are doubled in the failing heart. We hypothesized that HSF-1 is not activated in heart failure and that the increased expression of HSP60 was driven by NFkappaB activation. To test this hypothesis, we measured levels of heat shock factor (HSF) -1 and -2, the transcription factors controlling HSP expression, which were increased in heart failure. There was no increased phosphorylation of serine 230 or serine 303/307 in HSF-1, which are thought to regulate its activity; EMSA showed no increase in HSF binding activity with heart failure. Nonetheless, mRNA was increased for HSP60, but not HSP72. In contrast to HSF, NFkappaB activity was increased in heart failure. HSP60, but not HSP72, contained NFkappaB binding elements. ChIP assay demonstrated increased binding of NFkappaB to both of the NFkappaB binding elements in the heart failure HSP60 gene. TNFalpha treatment was used to test the role of NFkappaB activation in HSP60 expression in a cardiac cell line. TNFalpha increased HSP60 expression, and this could be prevented by pretreatment with siRNA inhibiting p65 expression. In conclusion, HSP72 is not increased in heart failure because HSF activity is not changed; increased expression of HSP60 may be driven by NFkappaB activation.


Assuntos
Chaperonina 60/genética , Regulação da Expressão Gênica , Proteínas de Choque Térmico HSP72/genética , Insuficiência Cardíaca/genética , Animais , Sítios de Ligação , Western Blotting , Chaperonina 60/metabolismo , Imunoprecipitação da Cromatina , Proteínas de Ligação a DNA/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , Proteínas de Choque Térmico HSP72/metabolismo , Insuficiência Cardíaca/fisiopatologia , Testes de Função Cardíaca , Fatores de Transcrição de Choque Térmico , NF-kappa B/metabolismo , Fosforilação , Fosfosserina/metabolismo , Ratos , Ratos Sprague-Dawley , Fatores de Transcrição/metabolismo
12.
Endocrinology ; 150(1): 212-9, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18787021

RESUMO

Although aging is known to lead to increased vascular stiffness, the role of estrogens in the prevention of age-related changes in the vasculature remains to be elucidated. To address this, we measured vascular function in the thoracic aorta in adult and old ovariectomized (ovx) rats with and without immediate 17beta-estradiol (E2) replacement. In addition, aortic mRNA and protein were analyzed for proteins known to be involved in vasorelaxation. Aging in combination with the loss of estrogens led to decreased vasorelaxation in response to acetylcholine and sodium nitroprusside, indicating either smooth muscle dysfunction and/or increased fibrosis. Loss of estrogens led to increased vascular tension in response to phenylephrine, which could be partially restored by E2 replacement. Levels of endothelial nitric oxide synthase and inducible nitric oxide synthase did not differ among the groups, nor did total nitrite plus nitrate levels. Old ovx exhibited decreased expression of both the alpha and beta-subunits of soluble guanylyl cyclase (sGC) and had impaired nitric oxide signaling in the vascular smooth muscle. Immediate E2 replacement in the aged ovx prevented both the impairment in vasorelaxation, and the decreased sGC receptor expression and abnormal sGC signaling within the vascular smooth muscle.


Assuntos
Envelhecimento/fisiologia , Vasos Sanguíneos/fisiologia , Estrogênios/deficiência , Contração Isométrica/fisiologia , Animais , Aorta/crescimento & desenvolvimento , Aorta/fisiologia , Vasos Sanguíneos/crescimento & desenvolvimento , Feminino , Músculo Liso Vascular/crescimento & desenvolvimento , Músculo Liso Vascular/fisiologia , Óxido Nítrico/sangue , Óxido Nítrico/metabolismo , Ovariectomia , Reação em Cadeia da Polimerase , RNA/genética , Ratos , Ratos Endogâmicos BN , Vasoconstrição/fisiologia , Vasodilatação/fisiologia
13.
Mol Ecol ; 16(24): 5277-93, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17971086

RESUMO

Parentage analyses of baleen whales are rare, and although mating systems have been hypothesized for some species, little data on realized male reproductive success are available and the patterns of male reproductive success have remained elusive for most species. Here we combine over 20 years of photo-identification data with high-resolution genetic data for the majority of individual North Atlantic right whales to assess paternity in this endangered species. There was significant skew in male reproductive success compared to what would be expected if mating was random (P < 0.001). The difference was due to an excess of males assigned zero paternities, a deficiency of males assigned one paternity, and an excess of males assigned as fathers for multiple calves. The variance in male reproductive success was high relative to other aquatically mating marine mammals, but was low relative to mammals where the mating system is based on resource- and/or mate-defence polygyny. These results are consistent with previous data suggesting that the right whale mating system represents one of the most intense examples of sperm competition in mammals, but that sperm competition on its own does not allow for the same degree of polygyny as systems where males can control access to resources and/or mates. The age distribution of assigned fathers was significantly biased towards older males (P < 0.05), with males not obtaining their first paternity until approximately 15 years of age, which is almost twice the average age of first fertilization in females (8 years), suggesting that mate competition is preventing younger males from reproducing. The uneven distribution of paternities results in a lower effective population size in this species that already has one of the lowest reported levels of genetic diversity, which may further inhibit reproductive success through mate incompatibility of genetically similar individuals.


Assuntos
Reprodução/fisiologia , Comportamento Sexual Animal/fisiologia , Baleias/fisiologia , Envelhecimento/fisiologia , Animais , Oceano Atlântico , Extinção Biológica , Feminino , Masculino , Densidade Demográfica , Fatores de Tempo , Baleias/classificação
14.
Am J Physiol Heart Circ Physiol ; 293(4): H2238-47, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17675567

RESUMO

Heat shock protein (HSP) 60 is a mitochondrial and cytosolic protein. Previously, we reported that HSP60 doubled in end-stage heart failure, even though levels of the protective HSP72 were unchanged. Furthermore, we observed that acute injury in adult cardiac myocytes resulted in movement of HSP60 to the plasma membrane. We hypothesized that the inflammatory state of heart failure would cause translocation of HSP60 to the plasma membrane and that this would provide a pathway for cardiac injury. Two models were used to test this hypothesis: 1) a rat model of heart failure and 2) human explanted failing hearts. We found that HSP60 localized to the plasma membrane and was also found in the plasma early in heart failure. Plasma membrane HSP60 localized to lipid rafts and was detectable on the cell surface with the use of both flow cytometry and confocal microscopy. Localization of HSP60 to the cell surface correlated with increased apoptosis. In heart failure, HSP60 is in the plasma membrane fraction, on the cell surface, and in the plasma. Membrane HSP60 correlated with increased apoptosis. Release of HSP60 may activate the innate immune system, promoting a proinflammatory state, including an increase in TNF-alpha. Thus abnormal trafficking of HSP60 to the cell surface may be an early trigger for myocyte loss and the progression of heart failure.


Assuntos
Apoptose , Cardiomiopatias/complicações , Chaperonina 60/metabolismo , Insuficiência Cardíaca/patologia , Microdomínios da Membrana/metabolismo , Miócitos Cardíacos/patologia , Idoso , Animais , Fator Natriurético Atrial/sangue , Cardiomiopatias/metabolismo , Cardiomiopatias/patologia , Cardiomiopatias/fisiopatologia , Citosol/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Feminino , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/fisiopatologia , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Mitocôndrias Cardíacas/metabolismo , Contração Miocárdica , Miócitos Cardíacos/metabolismo , Peptídeo Natriurético Encefálico/sangue , Transporte Proteico , Ratos , Ratos Sprague-Dawley , Fatores de Tempo , Fator de Necrose Tumoral alfa/sangue , Regulação para Cima
15.
Am J Physiol Heart Circ Physiol ; 292(6): H3052-6, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17307989

RESUMO

The heat shock proteins (HSP) are a highly conserved family of proteins with critical functions in protein folding, protein trafficking, and cell signaling. These proteins also protect the cell against injury. HSP60 has been found in the extracellular space and has been identified in the plasma of some individuals. HSP60 is thought to be a "danger signal" to the immune system and is also highly immunogenic. Thus extracellular HSP60 is possibly toxic to the cell. The mechanism by which HSP60 is released into the extracellular space is unknown, as is whether it is released by cardiac myocytes. We investigated several different pathways controlling protein release including the classic, Golgi-mediated pathway. We found that HSP60 is released via exosomes, and that within the exosome, HSP60 is tightly attached to the exosome membrane.


Assuntos
Chaperonina 60/metabolismo , Microdomínios da Membrana/metabolismo , Miócitos Cardíacos/metabolismo , Vesículas Secretórias/metabolismo , Amilorida/análogos & derivados , Amilorida/farmacologia , Animais , Brefeldina A/farmacologia , Caveolina 1/metabolismo , Hipóxia Celular , Complexo de Golgi/metabolismo , Proteínas de Choque Térmico HSC70/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Masculino , Microdomínios da Membrana/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Transporte Proteico , Ratos , Ratos Sprague-Dawley , Vesículas Secretórias/efeitos dos fármacos , Frações Subcelulares/metabolismo , beta-Ciclodextrinas/farmacologia
16.
AIDS Care ; 18(5): 417-25, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16777632

RESUMO

This study sought to identify correlates of poor health care utilization among HIV-positive injection drug users (IDUs) using Andersen's behavioural health model. We used baseline data from INSPIRE, a study of HIV-positive IDUs (n=1161) to identify predisposing, enabling, and need factors related to poor utilization (defined as fewer than two outpatient visits in the past six months, or identification of emergency room (ER) as the usual place for care). Using bivariate and multivariate models, we found a number of enabling factors that could facilitate the use of health care services such as having health insurance, having seen a case manager, and better engagement with health care providers. These enabling factors could be modified through interventions targeting HIV-positive IDUs. In addition, health insurance and case management appear to be important factors to address because they contributed in making other factors (e.g. lower education, lack of stable housing) non-significant barriers to outpatient care utilization. In the future, these findings may be used to inform the development of interventions that maximize use of scarce HIV resources and improve health care utilization among HIV-positive IDUs.


Assuntos
Soropositividade para HIV/terapia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Abuso de Substâncias por Via Intravenosa/terapia , Adulto , Assistência Ambulatorial/estatística & dados numéricos , Serviço Hospitalar de Emergência/estatística & dados numéricos , Feminino , Soropositividade para HIV/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Abuso de Substâncias por Via Intravenosa/complicações
17.
Shock ; 25(1): 43-9, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16369185

RESUMO

The molecular mechanisms that mediate gram-negative sepsis-associated myocardial dysfunction remain elusive. Myocardial expression of inflammatory mediators is Toll-like receptor 4 (TLR4) dependent. However, it remains to be elucidated whether TLR4, expressed on cardiac myocytes, mediates impairment of cardiac contractility after lipopolysaccharide (LPS) application. Cardiac myocyte contractility, measured as sarcomere shortening of isolated cardiac myocytes from C3H/HeJ (with nonfunctional TLR4) and C3H/HeN (control), were recorded at stimulation frequencies between 0.5 and 10 Hz and after incubation with 1 and 10 mug/mL LPS for up to 8 h. Control cells treated with LPS were investigated with and without a competitive LPS inhibitor (E5564) and a specific inducible nitric oxide synthase (iNOS) inhibitor S-methylisothiourea. In control mice, LPS reduced sarcomere shortening amplitude and prolonged duration of relaxation, whereas sarcomere shortening of C3H/HeJ cells was insensitive to LPS. NFkappaB and iNOS were upregulated after LPS application in control mice compared with C3H/HeJ. Inhibition of TLR4 by E5564 as well as inhibition of iNOS prevented the influence of LPS on contractile activity in control myocytes. LPS-dependent suppression of cardiac myocyte contractility was significantly blunted in C3H/HeJ mice. Competitive inhibition of functional TLR4 with E5564 protects cardiac myocyte contractility against LPS. These findings suggest that TLR4, expressed on cardiac myocytes, contributes to sepsis-induced myocardial dysfunction. E5564, currently under investigation in two clinical phase II trials, seems to be a new therapeutic option for the treatment of myocardial dysfunction in sepsis associated with endotoxemia.


Assuntos
Endotoxemia/metabolismo , Infecções por Bactérias Gram-Negativas/metabolismo , Contração Miocárdica , Miocárdio/metabolismo , Óxido Nítrico/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Cardiomiopatias/etiologia , Cardiomiopatias/metabolismo , Cardiomiopatias/patologia , Células Cultivadas , Endotoxemia/complicações , Endotoxemia/patologia , Inibidores Enzimáticos/farmacologia , Infecções por Bactérias Gram-Negativas/complicações , Infecções por Bactérias Gram-Negativas/patologia , Isotiurônio/análogos & derivados , Isotiurônio/farmacologia , Lipídeo A/análogos & derivados , Lipídeo A/farmacologia , Lipopolissacarídeos/farmacologia , Camundongos , Miocárdio/patologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , NF-kappa B/metabolismo , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/metabolismo , Sarcômeros/metabolismo , Sarcômeros/patologia , Receptor 4 Toll-Like/antagonistas & inibidores , Receptor 4 Toll-Like/deficiência
19.
Am J Physiol Heart Circ Physiol ; 289(6): H2519-25, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16100242

RESUMO

Heat shock protein (HSP)72, the inducible form of HSP70, protects cells against a variety of injuries, but underlying mechanisms are poorly defined. To investigate the protective effects of HSP72, multiple clones expressing wild-type (WT) HSP72 and two mutants with defective nucleolar and nuclear localization (M45 and 985A, respectively) were made with the tet-off system in C2C12 cells. Four different parameters of cell function/injury were examined after simulated ischemia: protein synthesis, polysome formation, DNA synthesis, and lactate dehydrogenase (LDH release). Overexpression of WT HSP72 was also compared to nontransfected C2C12 cells. As expected, overexpression of HSP72 protected against simulated ischemia and reoxygenation for all parameters. In contrast, both M45 and 985A showed abnormal protein synthesis and polysome formation, both after simulated ischemia and under control conditions. Total RNA was slightly reduced in M45 and 985A at baseline, but 1 h after hypoxia, RNA levels were protected in all clones but significantly decreased in nontransfected C2C12 cells. Clones expressing 985A had nuclear retention of mRNA, suggesting that HSP72 is needed for nuclear export of RNA. All clones, both WT and mutant, had protection of DNA synthesis compared to C2C12 cells, but 985A had greater release of LDH after injury than any other group. These results support a multifactoral protective effect of HSP72, some aspects dependent on nuclear localization with stress and some not. The protection of protein synthesis and polysome formation, and abnormalities in these with the mutants, support a role for HSP72 in these processes both in the normal cell and in injury.


Assuntos
Proteínas de Choque Térmico HSP72/metabolismo , Resposta ao Choque Térmico/fisiologia , Músculo Esquelético/fisiologia , Mioblastos/fisiologia , Biossíntese de Proteínas/fisiologia , RNA/metabolismo , Animais , Hipóxia Celular/fisiologia , Linhagem Celular , Proteínas de Choque Térmico HSP72/química , Proteínas de Choque Térmico HSP72/genética , Camundongos , Mutagênese Sítio-Dirigida , Polirribossomos/fisiologia , Relação Estrutura-Atividade
20.
AIDS Care ; 17 Suppl 1: S102-13, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16096122

RESUMO

To be effective and sustainable, HIV-prevention interventions need to be sufficiently powerful to counteract prevailing social norms and diffuse through the targeted community to provide social reinforcement for behaviour change. Social structural and environmental factors are major influences on HIV-related behaviours yet the dearth of conceptualization and operationalization of these factors impede progress in intervention development. In this paper we propose a social ecological perspective to intervention and highlight relevant theories from social psychology and organizational behaviour literatures. We examine social networks and social settings as micro-structural and environmental influences on HIV risk behaviours, social identities and norms, and as important targets for HIV-prevention intervention. Intervention approaches are proposed that target networks and behavioural settings and provide participants with socially meaningful and rewarding behavioural options that are consistent with valued prosocial identities or roles. Examples are presented on how such an approach has been utilized in prior HIV prevention interventions, including our social network-oriented intervention that trained disadvantaged former and current illicit drug users to conduct peer outreach. We describe how behavioural interventions may enhance or introduce new prosocial identities and social roles, and that network members may confer social approval to reinforce these identities and roles, leading to sustained behavioural risk reduction and changes in risk behaviour norms.


Assuntos
Infecções por HIV/prevenção & controle , Controles Informais da Sociedade , Serviços de Saúde Comunitária/métodos , Humanos , Comportamento de Redução do Risco , Assunção de Riscos , Comportamento Sexual , Apoio Social
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