Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45
Filtrar
Filtros adicionais











Intervalo de ano
1.
Basic Res Cardiol ; 114(2): 11, 2019 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-30673858

RESUMO

Coxsackieviruses of group B (CVB) are well-known causes of acute and chronic myocarditis. Chronic myocarditis can evolve into dilated cardiomyopathy (DCM) characterized by fibrosis and cardiac remodeling. Interleukin-1ß (IL-1ß) plays a decisive role in the induction of the inflammatory response as a consequence of viral replication. In this study, we analyzed the effects of IL-1ß neutralization on the transition of acute to chronic myocarditis in a mouse model of CVB3 myocarditis. Mice were treated with an anti-murine IL-1ß antibody as a surrogate for Canakinumab at different time points post CVB3 infection. Treatment was performed in the early phase (day 1-14 pi, day 3-14 pi) or at a later stage of myocarditis (day 14-28 pi). Subsequently, the hearts were examined histologically, immunohistochemically and by molecular biology. A significant reduction of viral replication, cardiac damage and inflammation was found after administration of the antibody in the early phase and in the later phase of infection. Furthermore, less collagen I deposition and a considerable reduction of fibrosis were found in antibody-treated mice. Using microarray analysis, a significant upregulation of various extracellular matrix and fibrosis-associated molecules was found in CVB3-infected mice, including TGF-ß, TIMP-1 and MMP12, as well as diverse matricellular proteins, whereas, these molecules were significantly downregulated in all IL-1ß antibody-treated infected mice. Neutralization of IL-1ß at different stages of enteroviral infection prevents the development of chronic viral myocarditis by reducing inflammation, interstitial fibrosis and adverse cardiac remodeling. These findings are relevant for the treatment of patients with acute and chronic myocarditis.


Assuntos
Interleucina-1beta/antagonistas & inibidores , Miocardite/patologia , Remodelação Ventricular/efeitos dos fármacos , Animais , Anticorpos Monoclonais/farmacologia , Doença Crônica , Infecções por Coxsackievirus/metabolismo , Infecções por Coxsackievirus/patologia , Enterovirus Humano B , Camundongos , Miocardite/metabolismo , Miocardite/virologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
2.
Front Immunol ; 9: 2303, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30349538

RESUMO

Myocarditis is an inflammatory disease of the heart muscle most commonly caused by viral infection and often maintained by autoimmunity. Virus-induced tissue damage triggers chemokine production and, subsequently, immune cell infiltration with pro-inflammatory and pro-fibrotic cytokine production follows. In patients, the overall inflammatory burden determines the disease outcome. Following the aim to define specific molecules that drive both immunopathology and/or autoimmunity in inflammatory heart disease, here we report on increased expression of colony stimulating factor 1 (CSF-1) in patients with myocarditis. CSF-1 controls monocytes originating from hematopoietic stem cells and subsequent progenitor stages. Both, monocytes and macrophages are centrally involved in mediating tissue damage and fibrotic scarring in the heart. CSF-1 influences monocytes via engagement of CSF-1 receptor, and it is also produced by cells of the mononuclear phagocyte system themselves. Based on this, we sought to modulate the virus-triggered inflammatory response in an experimental model of Coxsackievirus B3-induced myocarditis by silencing the CSF-1 axis in myeloid cells using nanoparticle-encapsulated siRNA. siCSF-1 inverted virus-mediated immunopathology as reflected by lower troponin T levels, a reduction of accumulating myeloid cells in heart tissue and improved cardiac function. Importantly, pathogen control was maintained and the virus was efficiently cleared from heart tissue. Since viral heart disease triggers heart-directed autoimmunity, in a second approach we investigated the influence of CSF-1 upon manifestation of heart tissue inflammation during experimental autoimmune myocarditis (EAM). EAM was induced in Balb/c mice by immunization with a myocarditogenic myosin-heavy chain-derived peptide dissolved in complete Freund's adjuvant. siCSF-1 treatment initiated upon established disease inhibited monocyte infiltration into heart tissue and this suppressed cardiac injury as reflected by diminished cardiac fibrosis and improved cardiac function at later states. Mechanistically, we found that suppression of CSF-1 production arrested both differentiation and maturation of monocytes and their precursors in the bone marrow. In conclusion, during viral and autoimmune myocarditis silencing of the myeloid CSF-1 axis by nanoparticle-encapsulated siRNA is beneficial for preventing inflammatory tissue damage in the heart and preserving cardiac function without compromising innate immunity's critical defense mechanisms.

3.
Hum Gene Ther ; 29(11): 1301-1314, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29739251

RESUMO

Coxsackievirus B3 (CVB3), a single-stranded RNA virus of the picornavirus family, has been described as a novel oncolytic virus. However, the CVB3 strain used induced hepatitis and myocarditis in vivo. It was hypothesized that oncolytic activity and safety of CVB3 depends on the virus strain and its specific receptor tropism. Different laboratory strains of CVB3 (Nancy, 31-1-93, and H3), which use the coxsackievirus and adenovirus receptor (CAR), and the strain PD, which uses N- and 6-O-sulfated heparan sulfate (HS) for entry into the cells, were investigated for their potential to lyse tumor cells and for their safety profile. The investigations were carried out in colorectal carcinoma. In vitro investigations showed variable infection efficiency and lysis of colorectal carcinoma cell lines by the CVB3 strains. The most efficient strain was PD, which was the only one that could lyse all investigated colorectal carcinoma cell lines. Lytic activity of CAR-dependent CVB3 did not correlate with CAR expression on cells, whereas there was a clear correlation between lytic activity of PD and its ability to bind to HS at the cell surface of colorectal carcinoma cells. Intratumoral injection of Nancy, 31-1-93, or PD into subcutaneous colorectal DLD1 cell tumors in BALB/c nude mice resulted in strong inhibition of tumor growth. The effect was seen in the injected tumor, as well as in a non-injected, contralateral tumor. However, all animals treated with 31-1-93 and Nancy developed systemic infection and died or were moribund and sacrificed within 8 days post virus injection. In contrast, five of the six animals treated with PD showed no signs of a systemic viral infection, and PD was not detected in any organ. The data demonstrate the potential of PD as a new oncolytic virus and HS-binding of PD as a key feature of oncolytic activity and improved safety.

4.
Cytokine ; 2017 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-28886971

RESUMO

Coxsackievirus B3 (CVB3) is an important inducer of myocarditis, which, in susceptible individuals, can chronify and eventually lead to the development of dilated cardiomyopathy and heart failure. The respective mechanisms are not completely understood. Here, we analyzed expression of the TRAF6 gene, encoding TNF receptor-associated factor 6 (TRAF6), a signal transduction scaffold protein that acts downstream of cytokine receptors, in heart tissue of susceptible and non-susceptible mouse strains. We found that after infection, TRAF6 expression was upregulated in both non-susceptible C57BL/6 wildtype and susceptible A.BY/SnJ and C57BL/6-TLR3 (-/-) mice, however, to different degrees. In infected HeLa cells, we also found moderately elevated TRAF6 levels after infection, in addition, activity of the transcription factor nuclear factor kappa B (NFκB), which can be activated downstream of TRAF6, was strongly enhanced in infected cells. To functionally analyze the role of TRAF6 with regard to infection progression, TRAF6 expression was knocked down in cultured HeLa cells using specific siRNAs. We found that reduction of TRAF6 expression had no effect on NFκB activation in response to infection. Taken together, our data suggest that CVB3 infection enhances TRAF6 levels, however, this induction might not be necessary for infection-induced NFκB activation.

5.
Am J Transplant ; 17(12): 3199-3209, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28805342

RESUMO

It has already been shown that neutralization of the activating NK cell receptor NKG2D in combination with co-stimulation blockade prolongs graft survival of vascularized transplants. In order to clarify the underlying cellular mechanisms, we transplanted complete MHC-disparate BALB/c-derived cardiac grafts into C57BL/6 wildtypes or mice deficient for NKG2D (Klrk1-/- ). Although median survival was 8 days for both recipient groups, we detected already at day 5 posttransplantation significantly greater intragraft frequencies of NKp46+ NK cells in Klrk1-/- recipients than in wildtypes. This was followed by a significantly greater infiltration of CD4+ , but a lesser infiltration of CD8+ T cell frequencies. Contrary to published observations, co-stimulation blockade with CTLA4-Ig resulted in a significant acceleration of cardiac rejection by Klrk1-/- recipients, and this result was confirmed by applying a neutralizing antibody against NKG2D to wildtypes. In both experimental setups, grafts derived from Klrk1-/- recipients were characterized by significantly higher levels of interferon-γ mRNA, and both CD4+ and CD8+ T cells displayed a greater capacity for degranulation and interferon-γ production. In summary, our results clearly illustrate that NKG2D expression in the recipient is important for cardiac allograft survival, thus supporting the hypothesis that impairment of NK cells prevents the establishment of graft acceptance.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto/imunologia , Transplante de Coração/efeitos adversos , Subfamília K de Receptores Semelhantes a Lectina de Células NK/fisiologia , Animais , Rejeição de Enxerto/metabolismo , Rejeição de Enxerto/patologia , Interferon gama/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Complicações Pós-Operatórias , Taxa de Sobrevida , Transplante Homólogo
6.
PLoS One ; 12(5): e0176311, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28531186

RESUMO

BACKGROUND: Diagnosis of viral myocarditis is difficult by clinical criteria but facilitated by detection of inflammation and viral genomes in endomyocardial biopsies. Parvovirus B19 (B19V) targets endothelial cells where viral nucleic acid is exclusively detected in the heart. Microparticles (MPs) are released after cell damage or activation of specific cells. We aimed to investigate whether circulating endothelial MPs (EMPs) in human and experimental models of myocarditis are associated with B19V myocarditis. METHODS: MPs were investigated in patients with myocarditis (n = 54), divided into two groups: B19V+ (n = 23) and B19V- (n = 31) and compared with healthy controls (HCTR, n = 25). MPs were also investigated in B19V transgenic mice (B19V-NS1+) and mice infected with coxsackievirus B3 (CVB3). MPs were analyzed with fluorescent activated cell sorting (FACS). RESULTS: In human samples, EMP subpopulation patterns were significantly different in B19V+ compared to B19V- and HCTR (p<0.001), with an increase of apoptotic but not activated EMPs. Other MPs such as platelet- (PMPs) leukocyte-(LMPs) and monocyte-derived MPs (MMPs) showed less specific patterns. Significantly different levels of EMPs were observed in transgenic B19V-NS1+ mice compared with CVB3-infected mice (p<0.001). CONCLUSION: EMP subpopulations are different in B19V+ myocarditis in humans and transgenic B19V mice reflecting vascular damage. EMP profiles might permit differentiation between endothelial-cell-mediated diseases like myocardial B19V infection and other causes of myocarditis.


Assuntos
Micropartículas Derivadas de Células/metabolismo , Miocardite/virologia , Infecções por Parvoviridae/metabolismo , Parvovirus B19 Humano/genética , Adulto , Idoso , Animais , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Miocardite/metabolismo , Infecções por Parvoviridae/diagnóstico , Parvovirus B19 Humano/isolamento & purificação
7.
PLoS One ; 12(3): e0172084, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28264039

RESUMO

OBJECTIVE: Acute and chronic forms of myocarditis are mainly induced by virus infections. As a consequence of myocardial damage and inflammation dilated cardiomyopathy and chronic heart failure may develop. The gold standard for the diagnosis of myocarditis is endomyocardial biopsies which are required to determine the etiopathogenesis of cardiac inflammatory processes. However, new non-invasive MRI techniques hold great potential in visualizing cardiac non-ischemic inflammatory lesions at high spatial resolution, which could improve the investigation of the pathophysiology of viral myocarditis. RESULTS: Here we present the discovery of a novel endogenous T2* MRI contrast of myocardial lesions in murine models of acute and chronic CVB3 myocarditis. The evaluation of infected hearts ex vivo and in vivo by 3D T2w and T2*w MRI allowed direct localization of virus-induced myocardial lesions without any MRI tracer or contrast agent. T2*w weighted MRI is able to detect both small cardiac lesions of acute myocarditis and larger necrotic areas at later stages of chronic myocarditis, which was confirmed by spatial correlation of MRI hypointensity in myocardium with myocardial lesions histologically. Additional in vivo and ex vivo MRI analysis proved that the contrast mechanism was due to a strong paramagnetic tissue alteration in the vicinity of myocardial lesions, effectively pointing towards iron deposits as the primary contributor of contrast. The evaluation of the biological origin of the MR contrast by specific histological staining and transmission electron microscopy revealed that impaired iron metabolism primarily in mitochondria caused iron deposits within necrotic myocytes, which induces strong magnetic susceptibility in myocardial lesions and results in strong T2* contrast. CONCLUSION: This T2*w MRI technique provides a fast and sensitive diagnostic tool to determine the patterns and the severity of acute and chronic enteroviral myocarditis and the precise localization of tissue damage free of MR contrast agents.


Assuntos
Imagem por Ressonância Magnética , Miocardite/diagnóstico por imagem , Miocardite/virologia , Doença Aguda , Animais , Biópsia , Doença Crônica , Modelos Animais de Doenças , Imagem por Ressonância Magnética/métodos , Camundongos , Miocardite/patologia , Miocárdio/patologia , Miocárdio/ultraestrutura , Fatores de Tempo
9.
Virchows Arch ; 469(5): 553-562, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27566306

RESUMO

Human enteroviruses, e.g. coxsackieviruses, induce a variety of severe acute and chronic forms of disease, including myocarditis, meningitis and diabetes mellitus type 1. To visualize enterovirus infection with a diagnostic intent, many studies have applied a commercially available antibody (anti-CVB5 VP1, clone 5-D8/1, Dako, Hamburg, Germany) that identifies VP1 of different enteroviral serotypes. Many antibodies, however, have been found to bind non-specifically to proteins of cardiomyocytes and in the interstitial space, resulting in non-specific staining in immunohistochemistry. In this paper we show that the anti-CVB5 VP1 antibody, recognizing VP1 of coxsackieviruses and widely used in diagnostics and research, shows strong cross-reactivity with cellular proteins in the heart (and pancreas) of humans and mice, which calls for a more specific antibody to be used for diagnostic purposes. We observed by Western blot analyses of lysates from human heart tissue samples and HeLa cells two cross-reactive bands when using clone 5-D8/1. Peptide mass fingerprinting (MALDI-TOF) identified these proteins as creatine kinase (B-type) and tubulin, confirming that this mAb detects cellular proteins in addition to viral VP1. In order to overcome the problems of false positive VP1 staining we generated a new highly specific and sensitive monoclonal antibody (Cox mAB 31A2) that recognizes VP1 from CVB3. The new antibody was characterized and was found to function well in immunohistochemistry, immunofluorescence staining, Western blotting, ELISA and FACS analyses.


Assuntos
Anticorpos Monoclonais/imunologia , Infecções por Enterovirus/virologia , Enterovirus/metabolismo , Miocardite/virologia , Animais , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Coração/virologia , Humanos , Imuno-Histoquímica/métodos , Camundongos
10.
Sci Rep ; 6: 28583, 2016 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-27339001

RESUMO

There is increasing evidence that 2009 pandemic H1N1 influenza viruses have evolved after pandemic onset giving rise to severe epidemics in subsequent waves. However, it still remains unclear which viral determinants might have contributed to disease severity after pandemic initiation. Here, we show that distinct mutations in the 2009 pandemic H1N1 virus genome have occurred with increased frequency after pandemic declaration. Among those, a mutation in the viral hemagglutinin was identified that increases 2009 pandemic H1N1 virus binding to human-like α2,6-linked sialic acids. Moreover, these mutations conferred increased viral replication in the respiratory tract and elevated respiratory droplet transmission between ferrets. Thus, our data show that 2009 H1N1 influenza viruses have evolved after pandemic onset giving rise to novel virus variants that enhance viral replicative fitness and respiratory droplet transmission in a mammalian animal model. These findings might help to improve surveillance efforts to assess the pandemic risk by emerging influenza viruses.


Assuntos
Furões/virologia , Vírus da Influenza A Subtipo H1N1/genética , Infecções por Orthomyxoviridae/virologia , Animais , Linhagem Celular , Cães , Genoma Viral/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Células Madin Darby de Rim Canino , Infecções por Orthomyxoviridae/metabolismo , Sistema Respiratório/virologia , Ácidos Siálicos/metabolismo , Virulência/genética , Replicação Viral/genética
11.
J Pathol ; 239(1): 84-96, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26890577

RESUMO

A comparative analysis of inflammation between solid organs following donor brain death (BD) is still lacking and the detailed influence of BD accelerating ischaemia-reperfusion injury (IRI) post-transplantation remains to be addressed. Applying a murine model of BD, we demonstrated that 4 h after BD organs were characterized by distinct inflammatory expression patterns. For instance, lipocalin 2 (LCN2), a marker of acute kidney injury, was selectively induced in BD livers but not in kidneys. BD further resulted in significantly reduced frequencies of CD3(+) CD4(+) , CD3(+) CD8(+) T cells and NKp46(+) NK cells in the liver, whereas BD kidneys and hearts were characterized by significantly lower frequencies of conventional dendritic cells (cDCs). Syngeneic models of kidney (KTx) and heart transplantation (HTx) illustrated stronger gene expression in engrafted BD hearts only, but 20 h post-transplantation both organs displayed comparable intragraft lymphocyte frequencies, except for NK cells and graft function. Moreover, the complement factor C3d deposit detected in small vessels and capillaries in cardiac syngrafts did not significantly differ between BD and sham-transplanted groups. Finally, no further influence of donor BD on graft survival was detected in an allogeneic heart transplantation setting (C57BL/6 grafts into BALB/c recipients). We show for the first time that BD organs are characterized by a varying inflammatory profile; however, BD does not accelerate IRI in syngeneic KTx and HTx.


Assuntos
Morte Encefálica/imunologia , Transplante de Coração , Transplante de Rim , Traumatismo por Reperfusão/etiologia , Animais , Antígenos CD/metabolismo , Citocinas/metabolismo , Rejeição de Enxerto/imunologia , Imunidade Celular/fisiologia , Rim/metabolismo , Fígado/metabolismo , Linfócitos/imunologia , Masculino , Camundongos Endogâmicos C57BL , Nefrite/etiologia , Traumatismo por Reperfusão/imunologia , Imunologia de Transplantes/imunologia
12.
Eur J Immunol ; 46(3): 619-33, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26578407

RESUMO

Cardiomyocyte death as a result of viral infection is an excellent model for dissecting the inflammatory stress response that occurs in heart tissue. We reported earlier that a specific proteasome isoform, the immunoproteasome, prevents exacerbation of coxsackievirus B3 (CVB3)-induced myocardial destruction and preserves cell vitality in heart tissue inflammation. Following the aim to decipher molecular targets of immunoproteasome-dependent proteolysis, we investigated the function and regulation of the soluble PRR Pentraxin3 (PTX3). We show that the ablation of PTX3 in mice aggravated CVB3-triggered inflammatory injury of heart tissue, without having any significant effect on viral titers. Thus, there might be a role of PTX3 in preventing damage-associated molecular pattern-induced cell death. We found that the catalytic activity of the immunoproteasome subunit LMP7 regulates the timely availability of factors controlling PTX3 production. We report on immunoproteasome-dependent alteration of ERK1/2 and p38MAPKs, which were both found to be involved in PTX3 expression control. Our finding of a cardioprotective function of immunoproteasome-dependent PTX3 expression revealed a crucial mechanism of the stress-induced damage response in myocardial inflammation. In addition to antigen presentation and cytokine production, proteolysis by the immunoproteasome can also regulate the innate immune response during viral infection.


Assuntos
Proteína C-Reativa/imunologia , Proteína C-Reativa/metabolismo , Proteínas do Tecido Nervoso/imunologia , Proteínas do Tecido Nervoso/metabolismo , Complexo de Endopeptidases do Proteassoma/imunologia , Complexo de Endopeptidases do Proteassoma/fisiologia , Animais , Proteína C-Reativa/deficiência , Proteína C-Reativa/genética , Células Cultivadas , Infecções por Coxsackievirus/imunologia , Infecções por Coxsackievirus/virologia , Modelos Animais de Doenças , Coração/anatomia & histologia , Coração/virologia , Imunidade Inata , Inflamação/virologia , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Miocardite/imunologia , Miocardite/virologia , Miocárdio/imunologia , Miócitos Cardíacos/patologia , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Complexo de Endopeptidases do Proteassoma/genética , Proteólise , Estresse Fisiológico , Carga Viral
13.
Clin Res Cardiol ; 104(12): 1033-43, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26008895

RESUMO

BACKGROUND: Risk stratification in patients with suspected myocarditis is pivotal for optimizing therapy. Stromal cell-derived factor 1 (SDF-1) is an inflammatory chemokine expressed in the inflamed and failing myocardium. Therefore, we aimed to investigate whether endomyocardial expression of SDF-1 identifies high-risk patients with suspected myocarditis. METHODS AND RESULTS: We prospectively enrolled 174 patients with non-ischemic HF who underwent endomyocardial biopsy for suspected myocarditis. Biopsies were analyzed using established histopathological and immunohistological criteria together with SDF-1 staining. SDF-1 was significantly enhanced in patients with inflammatory cardiomyopathy (65.4 % positive biopsies) as compared to patients with non-inflammatory cardiomyopathy (19.1 %, p < 0.001). SDF-1 expression levels correlated significantly with the degree of myocardial fibrosis (correlation coefficient r = 0.196; p = 0.010) since patients with severe myocardial fibrosis displayed high myocardial SDF-1 expression. During a mean follow-up of 27.5 months, 20 patients (11.5 %) died. The 4-year mortality rate was 26.0 % among the 92 SDF-1-positive patients vs. 9.5 % among the 82 SDF-1-negative patients (p = 0.001). On multivariable analysis which considered clinical (NYHA functional class, left ventricular ejection fraction), laboratory (brain natriuretic peptide, troponin I) and biopsy staining, SDF-1 was the strongest independent predictor of mortality (hazard ratio 6.1; 95 % confidence interval 1.4-27.5; p = 0.018). Subgroup analysis revealed SDF-1 as a predictor of mortality in both patients with inflammatory and non-inflammatory cardiomyopathy. CONCLUSIONS: Endomyocardial expression of SDF-1 is enhanced in inflammatory cardiomyopathy, positively correlates with myocardial fibrosis and identifies high-risk patients with suspected myocarditis.


Assuntos
Quimiocina CXCL12/metabolismo , Inflamação/diagnóstico , Miocardite/diagnóstico , Miocárdio/patologia , Adulto , Idoso , Biópsia , Feminino , Fibrose , Seguimentos , Humanos , Inflamação/mortalidade , Inflamação/patologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Miocardite/mortalidade , Miocardite/patologia , Estudos Prospectivos , Risco , Índice de Gravidade de Doença
14.
Int J Cardiol ; 176(3): 896-903, 2014 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-25223819

RESUMO

BACKGROUND: Cardiac inflammation has been suggested to play a critical role in the pathogenesis of inflammatory cardiomyopathy as well as in progressive heart failure (HF). CXC motif ligand 16 (CXCL16) is a recently discovered chemokine produced by several inflammatory cells and representing an important pathogenic mediator in the development of HF. The present study evaluates the diagnostic and prognostic relevance of CXCL16 expression in endomyocardial biopsies of consecutive patients with congestive HF. METHODS AND RESULTS: 174 patients (age 54.4±14.6 years) with congestive HF undergoing endomyocardial biopsy for diagnostic reasons were prospectively enrolled. Biopsies were analyzed using established histopathological and immunohistological criteria together with CXCL16 staining. CXCL16 was significantly enhanced in patients with inflammatory cardiomyopathy (78/127, 61.4%) as compared to patients with non-inflammatory cardiomyopathy (17/47, 36.2%, p=0.003). During a mean follow-up of 27.5 months, 20 patients (11.5%) reached the primary endpoint (death of all causes). Of all clinical (age, gender, NYHA functional class, systolic pulmonary artery pressure, left ventricular ejection fraction), laboratory (brain natriuretic peptide) and immunohistological (CXCL16) parameters tested, CXCL16 was the only independent predictor of death (hazard ratio 5.4; 95% confidence interval 1.2 to 24.0; p=0.027). Subgroup analysis revealed CXCL16 as a predictor of death in both patients with inflammatory and with non-inflammatory cardiomyopathy. CONCLUSION: According to the present observations CXCL16 is enhanced in inflammatory cardiomyopathy and turned out as an independent predictor of death in patients with HF undergoing endomyocardial biopsy.


Assuntos
Cardiomiopatias/metabolismo , Cardiomiopatias/mortalidade , Quimiocinas CXC/biossíntese , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/mortalidade , Receptores Depuradores/biossíntese , Adulto , Idoso , Biomarcadores/metabolismo , Cardiomiopatias/diagnóstico , Quimiocina CXCL16 , Estudos de Coortes , Feminino , Seguimentos , Insuficiência Cardíaca/diagnóstico , Humanos , Inflamação/diagnóstico , Inflamação/metabolismo , Inflamação/mortalidade , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Valor Preditivo dos Testes , Estudos Prospectivos
15.
Circulation ; 130(18): 1589-600, 2014 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-25165091

RESUMO

BACKGROUND: Common causative agents in the development of inflammatory cardiomyopathy include cardiotropic viruses such as coxsackievirus B3 (CVB3). Here, we investigated the role of the ubiquitin-like modifier interferon-stimulated gene of 15 kDa (ISG15) in the pathogenesis of viral cardiomyopathy. METHODS AND RESULTS: In CVB3-infected mice, the absence of protein modification with ISG15 was accompanied by a profound exacerbation of myocarditis and by a significant increase in mortality and heart failure. We found that ISG15 in cardiomyocytes contributed significantly to the suppression of viral replication. In the absence of an intact ISG15 system, virus titers were markedly elevated by postinfection day 8, and viral RNA persisted in ISG15(-/-) mice at postinfection day 28. Ablation of the ISG15 protein modification system in CVB3 infection predisposed mice to long-term disease with deposition of collagen fibers, all leading to inflammatory cardiomyopathy. We found that ISG15 acts as part of the intrinsic immunity in cardiomyocytes and detected no significant effects of ISG15 modification on the cellular immune response. ISG15 modification of CVB3 2A protease counterbalanced CVB3-induced cleavage of the host cell eukaryotic initiation factor of translation eIF4G in cardiomyocytes, thereby counterbalancing the shutoff of host cell translation in CVB3 infection. We demonstrate that ISG15 suppressed infectious virus yield in human cardiac myocytes and the induction of ISG15 in patients with viral cardiomyopathy. CONCLUSIONS: The ISG15 conjugation system represents a critical innate response mechanism in cardiomyocytes to fight the battle against invading pathogens, limiting inflammatory cardiomyopathy, heart failure, and death. Interference with the ISG15 system might be a novel therapeutic approach in viral cardiomyopathy.


Assuntos
Cardiomiopatia Dilatada/virologia , Infecções por Coxsackievirus/complicações , Citocinas/genética , Enterovirus Humano B/imunologia , Insuficiência Cardíaca/virologia , Adulto , Animais , Biópsia , Cardiomiopatia Dilatada/genética , Cardiomiopatia Dilatada/imunologia , Infecções por Coxsackievirus/genética , Infecções por Coxsackievirus/imunologia , Cisteína Endopeptidases/imunologia , Citocinas/imunologia , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/imunologia , Humanos , Imunidade Inata/imunologia , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/virologia , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Miócitos Cardíacos/fisiologia , Miócitos Cardíacos/virologia , Linfócitos T/imunologia , Linfócitos T/virologia , Ubiquitinas/genética , Ubiquitinas/imunologia , Ubiquitinas/metabolismo , Proteínas Virais/imunologia , Replicação Viral
16.
J Pathol ; 234(2): 164-77, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24797160

RESUMO

In enterovirus-induced cardiomyopathy, information regarding the detailed impact of natural killer (NK) cells on the outcome of the disease is limited. We therefore hypothesized that NK cells and certain NK cell receptors determine the different outcome of coxsackievirus B3 (CVB3) myocarditis. Here, we demonstrate in murine models that resistance to chronic CVB3 myocarditis in immunocompetent C57BL/6 mice is characterized by significantly more mature CD11b(high) NK cells, the presence of NKG2D on NK cells, and enhanced NKG2D-dependent cytotoxicity compared to CVB3-susceptible A.BY/SnJ mice. The highly protective role of NKG2D in myocarditis was further proven by in vivo neutralization of NKG2D as well as in NKG2D-deficient mice but was shown to be independent of CD8(+) T-cell-dependent immunity. Moreover, the adoptive transfer of immunocompetent C57BL/6 NK cells pre- (day -1) as well as post-infectionem (day +2) displayed the potential to prevent permissive A.BY/SnJ mice from a progressive outcome of CVB3 myocarditis reflected by significantly improved cardiopathology and heart function. Altogether, our results provide firm evidence for a protective role of NKG2D-activated NK cells in CVB3 myocarditis leading to an effective virus clearance, thus offering novel therapeutic options in the treatment of virus-induced myocarditis.


Assuntos
Cardiomiopatias/virologia , Enterovirus , Células Matadoras Naturais/metabolismo , Subfamília K de Receptores Semelhantes a Lectina de Células NK/metabolismo , Animais , Linfócitos T CD8-Positivos/imunologia , Cardiomiopatias/imunologia , Cardiomiopatias/patologia , Infecções por Coxsackievirus/prevenção & controle , Enterovirus/imunologia , Inflamação/imunologia , Células Matadoras Naturais/imunologia , Masculino , Camundongos Endogâmicos C57BL , Miocardite/etiologia , Miocardite/imunologia , Miocárdio/patologia , Subfamília K de Receptores Semelhantes a Lectina de Células NK/imunologia
17.
J Virol ; 88(13): 7345-56, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24741103

RESUMO

UNLABELLED: The coxsackievirus and adenovirus receptor (CAR) is a cell contact protein with an important role in virus uptake. Its extracellular immunoglobulin domains mediate the binding to coxsackievirus and adenovirus as well as homophilic and heterophilic interactions between cells. The cytoplasmic tail links CAR to the cytoskeleton and intracellular signaling cascades. In the heart, CAR is crucial for embryonic development, electrophysiology, and coxsackievirus B infection. Noncardiac functions are less well understood, in part due to the lack of suitable animal models. Here, we generated a transgenic mouse that rescued the otherwise embryonic-lethal CAR knockout (KO) phenotype by expressing chicken CAR exclusively in the heart. Using this rescue model, we addressed interspecies differences in coxsackievirus uptake and noncardiac functions of CAR. Survival of the noncardiac CAR KO (ncKO) mouse indicates an essential role for CAR in the developing heart but not in other tissues. In adult animals, cardiac activity was normal, suggesting that chicken CAR can replace the physiological functions of mouse CAR in the cardiomyocyte. However, chicken CAR did not mediate virus entry in vivo, so that hearts expressing chicken instead of mouse CAR were protected from infection and myocarditis. Comparison of sequence homology and modeling of the D1 domain indicate differences between mammalian and chicken CAR that relate to the sites important for virus binding but not those involved in homodimerization. Thus, CAR-directed anticoxsackievirus therapy with only minor adverse effects in noncardiac tissue could be further improved by selectively targeting the virus-host interaction while maintaining cardiac function. IMPORTANCE: Coxsackievirus B3 (CVB3) is one of the most common human pathogens causing myocarditis. Its receptor, the coxsackievirus and adenovirus receptor (CAR), not only mediates virus uptake but also relates to cytoskeletal organization and intracellular signaling. Animals without CAR die prenatally with major cardiac malformations. In the adult heart, CAR is important for virus entry and electrical conduction, but its nonmuscle functions are largely unknown. Here, we show that chicken CAR expression exclusively in the heart can rescue the otherwise embryonic-lethal CAR knockout phenotype but does not support CVB3 infection of adult cardiomyocytes. Our findings have implications for the evolution of virus-host versus physiological interactions involving CAR and could help to improve future coxsackievirus-directed therapies inhibiting virus replication while maintaining CAR's cellular functions.


Assuntos
Proteína de Membrana Semelhante a Receptor de Coxsackie e Adenovirus/fisiologia , Infecções por Coxsackievirus/prevenção & controle , Coração/fisiologia , Miocardite/prevenção & controle , Replicação Viral , Animais , Western Blotting , Células Cultivadas , Galinhas , Infecções por Coxsackievirus/virologia , Enterovirus Humano B/fisiologia , Imunofluorescência , Células HeLa , Coração/virologia , Humanos , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Miocardite/virologia
18.
Cell Physiol Biochem ; 33(1): 52-66, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24401606

RESUMO

BACKGROUND: Heme oxygenase-1 (HO-1), which is suggested to play a role in defending the organism against oxidative stress-mediated injuries, can be induced by diverse factors including viruses and iron. As coxsackievirus B3 (CVB3)-infected SWR/J mice susceptible for chronic myocarditis were found to have a significant iron incorporation and HO-1 upregulation in the myocardium, we aimed to investigate the molecular interplay between HO-1 expression and iron homeostasis in the outcome of viral myocarditis. METHODS AND RESULTS: In susceptible SWR/J mice, but not in resistant C57BL/6 mice, we observed at later stages of CVB3 myocarditis significant iron deposits in macrophages and also in cardiomyocytes, which were spatially associated with oxidative stress, upregulation of HO-1 and caspase-3 activation. HO-1, which is also expressed in cultivated RAW 264.7 macrophages upon incubation with iron and/or CVB3, could be downregulated by inhibition of NO/iNOS using L-NAME. Moreover, specific inhibition of HO-1 by tin mesoporphyrin revealed a suppression of superoxide production in iron and/or CVB3-treated macrophages. The molecular relationship of HO-1 and caspase-3 activation was proven by downregulation with HO-1 siRNA in iron- and/or CVB3-treated cultivated cells. Importantly, iron was found to increase viral replication in vitro. CONCLUSION: These results indicate that HO-1 induces a paracrine signalling in macrophages via reactive oxygen species production, mediating apoptosis of heart muscle cells at later stages of myocarditis. Notably, in genetically susceptible mice iron potentiates the detrimental effects of CVB3 by the NO/HO-1 pathway, thus increasing cardiac pathogenicity.


Assuntos
Apoptose , Infecções por Coxsackievirus/enzimologia , Enterovirus Humano B/fisiologia , Heme Oxigenase-1/metabolismo , Miocardite/enzimologia , Estresse Oxidativo , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Técnicas de Cocultura , Infecções por Coxsackievirus/patologia , Ativação Enzimática/efeitos dos fármacos , Indução Enzimática/efeitos dos fármacos , Inativação Gênica/efeitos dos fármacos , Células HeLa , Heme Oxigenase-1/genética , Humanos , Ferro/metabolismo , Ferro/farmacologia , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Miocardite/patologia , Miocárdio/metabolismo , Miocárdio/patologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Células RAW 264.7 , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Regulação para Cima/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
19.
MAGMA ; 27(1): 101-6, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23824166

RESUMO

OBJECTIVE: This paper introduces a new approach permitting for the first time a specific, non-invasive diagnosis of myocarditis by visualizing the infiltration of immune cells into the myocardium. MATERIALS AND METHODS: The feasibility of this approach is shown in a murine model of viral myocarditis. Our study uses biochemically inert perfluorocarbons (PFCs) known to be taken up by circulating monocytes/macrophages after intravenous injection. RESULTS: In vivo (19)F MRI at 9.4 T demonstrated that PFC-loaded immune cells infiltrate into inflamed myocardial areas. Because of the lack of any fluorine background in the body, detected (19)F signals of PFCs are highly specific as confirmed ex vivo by flow cytometry and histology. CONCLUSION: Since PFCs are a family of compounds previously used clinically as blood substitutes, the technique described in our paper holds the potential as a new imaging modality for the diagnosis of myocarditis in man.


Assuntos
Imagem por Ressonância Magnética/métodos , Miocardite/virologia , Animais , Citometria de Fluxo/métodos , Flúor/química , Fluorcarbonetos/química , Injeções Intravenosas , Macrófagos/citologia , Masculino , Camundongos , Monócitos/citologia , Miocárdio/imunologia , Miocárdio/patologia
20.
Basic Res Cardiol ; 108(6): 388, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24065117

RESUMO

Endogenous circulation of bone marrow-derived cells (BMCs) was observed in patients with dilated cardiomyopathy (DCM) who showed cardiac upregulation of Vascular Cell Adhesion Protein-1 (VCAM-1). However, the underlying pathophysiology is currently unknown. Thus, we aimed to analyze circulation, migration and G-CSF-based mobilization of BMCs in a murine model of virus-induced DCM. Mice with coxsackievirus B3 (CVB3) induced DCM and healthy controls were analyzed regarding their myocardial homing factors by PCR. To determine cardiac VCAM-1 expression ELISA and immunohistochemistry were applied. Flow cytometry was performed to analyze BMCs. Cardiac diameters and function were evaluated by echocardiography before and 4 weeks after G-CSF treatment. In murine CVB3-induced DCM an increase of BMCs in peripheral blood and a decrease of BMCs in bone marrow was observed. We found an enhanced migration of Very Late Antigen-4 (VLA-4⁺) BMCs to the diseased heart overexpressing VCAM-1 and higher numbers of CD45⁻CD34⁻Sca-1⁺ and CD45⁻CD34⁻c-kit⁺ cells. Mobilization of BMCs by G-CSF boosted migration along the VCAM-1/VLA-4 axis and reduced apoptosis of cardiomyocytes. Significant improvement of cardiac function was detected by echocardiography in G-CSF-treated mice. Blocking VCAM-1 by a neutralizing antibody reduced the G-CSF-dependent effects on stem cell migration and cardiac function. This is the first study showing that in virus-induced DCM VCAM-1/VLA-4 interaction is crucial for recruitment of circulating BMCs leading to beneficial anti-apoptotic effects resulting in improved cardiac function after G-CSF-induced mobilization.


Assuntos
Células da Medula Óssea/citologia , Cardiomiopatia Dilatada/fisiopatologia , Movimento Celular/fisiologia , Integrina alfa4beta1/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismo , Animais , Cardiomiopatia Dilatada/metabolismo , Cardiomiopatia Dilatada/virologia , Infecções por Coxsackievirus , Modelos Animais de Doenças , Ecocardiografia , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Fator Estimulador de Colônias de Granulócitos/metabolismo , Fator Estimulador de Colônias de Granulócitos/farmacologia , Humanos , Imuno-Histoquímica , Camundongos , Reação em Cadeia da Polimerase em Tempo Real , Células-Tronco/citologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA