Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 137
Filtrar
1.
J Clin Immunol ; 2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33660144

RESUMO

Cardiomyopathies are an important cause of heart failure and sudden cardiac death. Little is known about the role of rare genetic variants in inflammatory cardiomyopathy. Chronic Chagas disease cardiomyopathy (CCC) is an inflammatory cardiomyopathy prevalent in Latin America, developing in 30% of the 6 million patients chronically infected by the protozoan Trypanosoma cruzi, while 60% remain free of heart disease (asymptomatic (ASY)). The cytokine interferon-γ and mitochondrial dysfunction are known to play a major pathogenetic role. Chagas disease provides a unique model to probe for genetic variants involved in inflammatory cardiomyopathy. METHODS: We used whole exome sequencing to study nuclear families containing multiple cases of Chagas disease. We searched for rare pathogenic variants shared by all family members with CCC but absent in infected ASY siblings and in unrelated ASY. RESULTS: We identified heterozygous, pathogenic variants linked to CCC in all tested families on 22 distinct genes, from which 20 were mitochondrial or inflammation-related - most of the latter involved in proinflammatory cytokine production. Significantly, incubation with IFN-γ on a human cardiomyocyte line treated with an inhibitor of dihydroorotate dehydrogenase brequinar (enzyme showing a loss-of-function variant in one family) markedly reduced mitochondrial membrane potential (ΔψM), indicating mitochondrial dysfunction. CONCLUSION: Mitochondrial dysfunction and inflammation may be genetically determined in CCC, driven by rare genetic variants. We hypothesize that CCC-linked genetic variants increase mitochondrial susceptibility to IFN-γ-induced damage in the myocardium, leading to the cardiomyopathy phenotype in Chagas disease. This mechanism may also be operative in other inflammatory cardiomyopathies.

2.
Arq Bras Cardiol ; 116(2): 248-256, 2021 02.
Artigo em Inglês, Português | MEDLINE | ID: mdl-33656072

RESUMO

BACKGROUND: The histopathological characteristics of Chagas disease (ChD) are: presence of myocarditis, destruction of heart fibers, and myocardial fibrosis. Galectin-3 (Gal-3) is a biomarker involved in the mechanism of fibrosis and inflammation that may be useful for risk stratification of individuals with ChD. OBJECTIVES: We sought to evaluate whether high Gal-3 levels are associated with severe forms of Chagas cardiomyopathy (CC) and whether they are predictive of mortality. METHODS: We studied anti-T. cruzi positive blood donors (BD): Non-CC-BD (187 BD without CC with normal electrocardiogram [ECG] and left ventricular ejection fraction [LVEF]); CC-Non-Dys-BD (46 BD with CC with abnormal ECG but normal LVEF); and 153 matched serum-negative controls. This cohort was composed of 97 patients with severe CC (CC-Dys). We used Kruskall-Wallis and Spearman's correlation to test hypothesis of associations, assuming a two-tailed p<0.05 as significant. RESULTS: The Gal-3 level was 12.3 ng/mL for Non-CC-BD, 12.0 ng/mL for CC-Non-Dys-BD, 13.8 ng/mL for controls, and 15.4 ng/mL for CC-Dys. LVEF<50 was associated with higher Gal-3 levels (p=0.0001). In our linear regression adjusted model, we found association between Gal-3 levels and echocardiogram parameters in T. cruzi-seropositive subjects. In CC-Dys patients, we found a significant association of higher Gal-3 levels (≥15.3 ng/mL) and subsequent death or heart transplantation in a 5-year follow-up (Hazard ratio - HR 3.11; 95%CI 1.21-8.04; p=0.019). CONCLUSIONS: In ChD patients, higher Gal-3 levels were significantly associated with severe forms of the disease and more long-term mortality, which means it may be a useful means to identify high-risk patients. (Arq Bras Cardiol. 2021; 116(2):248-256).


Assuntos
Cardiomiopatia Chagásica , Doença de Chagas , Biomarcadores , Galectina 3 , Humanos , Volume Sistólico , Função Ventricular Esquerda
3.
Clin Infect Dis ; 2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33539531

RESUMO

BACKGROUND: Chagas disease is an infectious disease caused by the parasite Trypanosoma cruzi and is endemic from Latin American countries. The goal of our study was to identify novel genetic loci associated with chronic Chagas cardiomyopathy development in Chagas disease patients from different Latin American populations. METHODS: We performed a cross-sectional, nested case-control study including three sample collections from Colombia, Argentina and Bolivia. Samples were genotyped to conduct a genome-wide association study (GWAS). These results were meta-analyzed with summary statistic data from Brazil, gathering a total of 3,413 Chagas disease patients. To identify the functional impact of the associated variant and its proxies we performed an in silico analysis of this region. RESULTS: The meta-analysis revealed a novel genome-wide statistically significant association with chronic Chagas cardiomyopathy development in rs2458298 (OR=0.90, 95%CI=0.87-0.94, p-value=3.27x10 -08), nearby the SAC3D1 gene. In addition, further in silico analyses displayed functional relationships between the associated variant and the SNX15, BAFT2 and FERMT3 genes, related to cardiovascular traits. CONCLUSIONS: Our findings support the role of the host genetic factors in the susceptibility to the development of the chronic cardiac form of this neglected disease.

4.
Arq. bras. cardiol ; 116(2): 248-256, fev. 2021. tab, graf
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1153000

RESUMO

Resumo Fundamento As características histopatológicas da doença de Chagas (DCC) são: presença de miocardite, destruição das fibras cardíacas e fibrose miocárdica. A Galectina-3 (Gal-3) é um biomarcador envolvido no mecanismo de fibrose e inflamação que pode ser útil para a estratificação de indivíduos com DCC por risco. Objetivos Nosso objetivo foi avaliar se níveis elevados de Gal-3 estão associados a formas graves de cardiomiopatia chagásica (CC) e são preditivos de mortalidade. Métodos Estudamos doadores de sangue (DS) positivos para anti-T. cruzi: não-CC-DS (187 DS sem CC com eletrocardiograma [ECG] e fração de ejeção do ventrículo esquerdo [FEVE] normais); CC-Não-Dis-DS (46 DS com CC e apresentando ECG anormal, mas FEVE normal); e 153 controles negativos correspondentes. Esta amostra foi composta por 97 pacientes com CC grave (CC-Dis). Usamos as correlações de Kruskall-Wallis e Spearman para testar a hipótese de associações, assumindo um p bicaudal <0,05 como significativo. Resultados O nível de Gal-3 foi de 12,3 ng/mL para não-CC-DS, 12,0 ng/mL para CC-Não-Dis-DS, 13,8 ng/mL para controles e 15,4 ng/mL para CC-Dis. FEVE <50 foi associada a níveis mais elevados de Gal-3 (p=0,0001). Em nosso modelo de regressão linear ajustado, encontramos associação entre os níveis de Gal-3 e os parâmetros do ecocardiograma em indivíduos positivos para T. cruzi. Nos pacientes CC-Dis, encontramos uma associação significativa de níveis mais elevados de Gal-3 (≥15,3 ng/mL) e morte ou transplante cardíaco em acompanhamento de cinco anos (Hazard ratio - HR 3,11; IC95% 1,21- 8,04; p=0,019). Conclusões Em pacientes com CC, níveis mais elevados de Gal-3 estiveram significativamente associados a formas graves da doença e maior taxa de mortalidade em longo prazo, o que significa que pode ser um meio efetivo para identificar pacientes de alto risco. (Arq Bras Cardiol. 2021; 116(2):248-256)


Abstract Background The histopathological characteristics of Chagas disease (ChD) are: presence of myocarditis, destruction of heart fibers, and myocardial fibrosis. Galectin-3 (Gal-3) is a biomarker involved in the mechanism of fibrosis and inflammation that may be useful for risk stratification of individuals with ChD. Objectives We sought to evaluate whether high Gal-3 levels are associated with severe forms of Chagas cardiomyopathy (CC) and whether they are predictive of mortality. Methods We studied anti-T. cruzi positive blood donors (BD): Non-CC-BD (187 BD without CC with normal electrocardiogram [ECG] and left ventricular ejection fraction [LVEF]); CC-Non-Dys-BD (46 BD with CC with abnormal ECG but normal LVEF); and 153 matched serum-negative controls. This cohort was composed of 97 patients with severe CC (CC-Dys). We used Kruskall-Wallis and Spearman's correlation to test hypothesis of associations, assuming a two-tailed p<0.05 as significant. Results The Gal-3 level was 12.3 ng/mL for Non-CC-BD, 12.0 ng/mL for CC-Non-Dys-BD, 13.8 ng/mL for controls, and 15.4 ng/mL for CC-Dys. LVEF<50 was associated with higher Gal-3 levels (p=0.0001). In our linear regression adjusted model, we found association between Gal-3 levels and echocardiogram parameters in T. cruzi-seropositive subjects. In CC-Dys patients, we found a significant association of higher Gal-3 levels (≥15.3 ng/mL) and subsequent death or heart transplantation in a 5-year follow-up (Hazard ratio - HR 3.11; 95%CI 1.21-8.04; p=0.019). Conclusions In ChD patients, higher Gal-3 levels were significantly associated with severe forms of the disease and more long-term mortality, which means it may be a useful means to identify high-risk patients. (Arq Bras Cardiol. 2021; 116(2):248-256)

5.
Infect Genet Evol ; : 104671, 2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-33301989

RESUMO

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi. During the chronic phase of disease, while most infected people do not present symptoms, characterizing the asymptomatic form, some patients develop the cardiac form or chronic chagasic cardiomyopathy, which is considered the most severe manifestation of this disease. Considering that the activation of the PI3Kγ signaling pathway is essential for an efficient immune response against T. cruzi infection, we evaluated the PIK3CG C > T (rs1129293) polymorphism in exon 3 of this gene, which encodes the catalytic subunit of PI3Kγ. The PIK3CG CT and TT genotypes were found to be associated with an increased risk of developing the cardiac form of the disease rather than the asymptomatic or digestive forms. In conclusion, the presence of the T allele at single or double doses may differentiate the cardiac from other clinical manifestations of Chagas disease. This finding should help in further studies to evaluate the mechanisms underlying the differential association of PIK3CG in Chagas disease.

6.
PLoS Negl Trop Dis ; 14(12): e0008889, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33351798

RESUMO

Chronic Chagas disease cardiomyopathy (CCC), an especially aggressive inflammatory dilated cardiomyopathy caused by lifelong infection with the protozoan Trypanosoma cruzi, is a major cause of cardiomyopathy in Latin America. Although chronic myocarditis may play a major pathogenetic role, little is known about the molecular mechanisms responsible for its severity. The aim of this study is to study the genes and microRNAs expression in tissues and their connections in regards to the pathobiological processes. To do so, we integrated for the first time global microRNA and mRNA expression profiling from myocardial tissue of CCC patients employing pathways and network analyses. We observed an enrichment in biological processes and pathways associated with the immune response and metabolism. IFNγ, TNF and NFkB were the top upstream regulators. The intersections between differentially expressed microRNAs and differentially expressed target mRNAs showed an enrichment in biological processes such as Inflammation, inflammation, Th1/IFN-γ-inducible genes, fibrosis, hypertrophy, and mitochondrial/oxidative stress/antioxidant response. MicroRNAs also played a role in the regulation of gene expression involved in the key cardiomyopathy-related processes fibrosis, hypertrophy, myocarditis and arrhythmia. Significantly, a discrete number of differentially expressed microRNAs targeted a high number of differentially expressed mRNAs (>20) in multiple processes. Our results suggest that miRNAs orchestrate expression of multiple genes in the major pathophysiological processes in CCC heart tissue. This may have a bearing on pathogenesis, biomarkers and therapy.


Assuntos
Cardiomiopatia Chagásica/metabolismo , Cardiomiopatia Chagásica/patologia , Regulação da Expressão Gênica/fisiologia , MicroRNAs/metabolismo , Doença Crônica , Genoma Humano , Humanos , MicroRNAs/genética , Análise de Componente Principal
7.
Curr Drug Targets ; 2020 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-33238855

RESUMO

Chagas disease, caused by the protozoan Trypanosoma cruzi is a neglected tropical disease with high prevalence (5.7 million in Latin America, WHO 2015), significant burden and significant morbimortality, mostly due to severe heart disorders during the chronic phase of infection. Chagas disease is endemic in Latin America, and medical care for the disease is the major expense for Brazil's Universal Healthcare System (Sistema Único de Saúde (SUS). The efficacy of the available drugs benznidazole and nifurtimox is low for the chronic phase of Chagas disease, the phase in which most patients are diagnosed, and there are frequent side effects and drug resistance occurs. The rapid deployment of new drug regimens that are effective for the chronic phase treatment, which are low-cost and less toxic than the currently available therapy is a global priority. Repurposing drugs already in clinical use with other combinations would be the fastest and safest strategy for treating patients with Chagas disease. Our hypothesis is that the combined treatment using repurposing drugs with benznidazole will be more efficacious than benznidazole alone, this needs to be tested further both in vitro and in animal models to understand the efficacy of the treatment prior to performing human clinical trials. We further hypothesize that producing nanoparticle formulation of the drugs can reduce their toxicity and improve therapeutic use.

8.
Metab Brain Dis ; 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33170418

RESUMO

Lithium activates Wnt/ß-catenin signaling leading to stabilization of free cytosolic ß-catenin. The aim of the present study is to evaluate the in vivo effect of acute and chronic lithium treatment on the expression of ß-catenin target genes, addressing its transcripts HIG2, Bcl-xL, Cyclin D1, c-myc, in cortical and hippocampal tissue from adult mice. Lithium doses were established to yield therapeutic working concentrations. In acute treatment, mice received a 300µL of a 350 mg/kg solution of LiCl by gavage, and were euthanized after 2 h, 6 h and 12 h. To determine the effect of chronic treatment, animals were continuously fed either with chow supplemented with 2 g/kg Li2CO3, or regular chow (controls), being euthanized after 30 days. All animals had access to drinking water and 0.9% saline ad libitum. After acute and chronic treatments samples of peripheral blood were obtained from the tail vein for each animal, and serum concentrations of lithium were determined. All transcripts were up-regulated in cortical and hippocampal tissues of lithium-treated mice, both under acute and chronic treatments. There was a positive correlation between serum lithium concentrations and the increment in the expression of all transcripts. This effect was observed in all time points of the acute treatment (i.e., 2, 6 and 12 hours) and also after 30 days. We conclude that Wnt/ß-catenin transcriptional response (HIG2, Bcl-xL, Cyclin D1 and c-myc) is up-regulated in the mouse brain in response to acute and chronic lithium treatment at therapeutic concentrations.

10.
Front Immunol ; 11: 1386, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32733459

RESUMO

Background: Chagas disease, caused by the protozoan Trypanosoma cruzi, is endemic in Latin America. Thirty percent of infected individuals develop chronic Chagas cardiomyopathy (CCC), an inflammatory dilated cardiomyopathy that is the most important clinical consequence of T. cruzi infection, while the others remain asymptomatic (ASY). IFN-γ and IFN-γ-producing Th1-type T cells are increased in peripheral blood and CCC myocardium as compared to ASY patients, while the Th1-antagonizing cytokine IL-10 is more expressed in ASY patients. Importantly IFN-γ-producing Th1-type T cells are the most frequent cytokine-producing T cell subset in CCC myocardium, while expression of Th1-antagonizing cytokines IL-10 and IL-4 is unaltered. The control of IFN-γ production by Th1-type T cells may be a key event for progression toward CCC. A genetic component to disease progression was suggested by the familial aggregation of cases and the association of gene polymorphisms with CCC development. We here investigate the role of gene polymorphisms (SNPs) in several genes involved in the control of IFN-γ production and Th1 T cell differentiation in CCC development. Methods: We studied a Brazilian population including 315 CCC cases and 118 ASY subjects. We assessed 35 Tag SNPs designed to represent all the genetic information contained in the IL12B, IL10, IFNG, and IL4 genes. Results: We found 2 IL12 SNPs (rs2546893, rs919766) and a trend of association for a IL10 SNP (rs3024496) to be significantly associated with the ASY group. these associations were confirmed by multivariate analysis and allele tests. The rs919766C, 12rs2546893G, and rs3024496C alleles were associated to an increase risk to CCC development. Conclusions: Our data show that novel polymorphisms affecting IL12B and IL10, but not IFNG or IL4 genes play a role in genetic susceptibility to CCC development. This might indicate that the increased Th1 differentiation and IFN-γ production associated with CCC is genetically controlled.

11.
Front. immunol ; 11(1386): 1-12, July., 2020. tab.
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1122895

RESUMO

BACKGROUND: Chagas disease, caused by the protozoan Trypanosoma cruzi, is endemic in Latin America. Thirty percent of infected individuals develop chronic Chagas cardiomyopathy (CCC), an inflammatory dilated cardiomyopathy that is the most important clinical consequence of T. cruzi infection, while the others remain asymptomatic (ASY). IFN-γ and IFN-γ-producing Th1-type T cells are increased in peripheral blood and CCC myocardium as compared to ASY patients, while the Th1-antagonizing cytokine IL-10 is more expressed in ASY patients. Importantly IFN-γ-producing Th1-type T cells are the most frequent cytokine-producing T cell subset in CCC myocardium, while expression of Th1-antagonizing cytokines IL-10 and IL-4 is unaltered. The control of IFN-γ production by Th1-type T cells may be a key event for progression toward CCC. A genetic component to disease progression was suggested by the familial aggregation of cases and the association of gene polymorphisms with CCC development. We here investigate the role of gene polymorphisms (SNPs) in several genes involved in the control of IFN-γ production and Th1 T cell differentiation in CCC development. METHODS: We studied a Brazilian population including 315 CCC cases and 118 ASY subjects. We assessed 35 Tag SNPs designed to represent all the genetic information contained in the IL12B, IL10, IFNG, and IL4 genes. RESULTS: We found 2 IL12 SNPs (rs2546893, rs919766) and a trend of association for a IL10 SNP (rs3024496) to be significantly associated with the ASY group. these associations were confirmed by multivariate analysis and allele tests. The rs919766C 12rs2546893G, and rs3024496C alleles were associated to an increase risk to CCC development. CONCLUSIONS: Our data show that novel polymorphisms affecting IL12B and IL10, but not IFNG or IL4 genes play a role in genetic susceptibility to CCC development. This might indicate that the increased Th1 differentiation and IFN-γ production associated with CCC is genetically controlled.


Assuntos
Doença de Chagas , Interleucina-12 , Cardiomiopatias
12.
J Leukoc Biol ; 108(4): 1183-1197, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32362022

RESUMO

Heterogeneity and high plasticity are common features of cells from the mononuclear phagocyte system: monocytes (MOs), macrophages, and dendritic cells (DCs). Upon activation by microbial agents, MO can differentiate into MO-derived DCs (MODCs). In previous work, we have shown that during acute infection with Plasmodium berghei ANKA (PbA), MODCs become, transiently, the main CD11b+ myeloid population in the spleen (SP) and once recruited to the brain play an important role in the development of experimental cerebral malaria (ECM). Here, we isolated 4 cell populations: bone marrow (BM) MOs (BM-MOs) and SP-MOs from uninfected mice; BM inflammatory MOs (BM-iMOs) and SP-MODCs from PbA-infected mice and used a system biology approach to a holistic transcriptomic comparison and provide an interactome analysis by integrating differentially expressed miRNAs (DEMs) and their differentially expressed gene targets (DEGs) data. The Jaccard index (JI) was used for gauging the similarity and diversity among these cell populations. Whereas BM-MOs, BM-iMOs, and SP-MOs presented high similarity of DEGs, SP-MODCs distinguished by showing a greater number of DEGs. Moreover, functional analysis identified an enrichment in canonical pathways, such as DC maturation, neuroinflammation, and IFN signaling. Upstream regulator analysis identified IFNγ as the potential upstream molecule that can explain the observed DEMs-Target DEGs intersections in SP-MODCs. Finally, directed target analysis and in vivo/ex vivo assays indicate that SP-MODCs differentiate in the SP and IFNγ is a main driver of this process.

14.
Front Immunol ; 10: 1637, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31396209

RESUMO

MicroRNAs (miRs) are master regulators of post-transcriptional gene expression, and they are often dysregulated in individuals suffering from diabetes. We investigated the roles of miR-101-3p and miR-204-5p, both of which negatively regulate insulin secretion and cell survival and are highly expressed in pancreatic ß cells, in the context of type 1 diabetes (T1D) pathogenesis. Using quantitative real time PCR, we evaluated serum levels of miR-101-3p and miR-204-5p in four groups, including recent-onset T1D patients (T1D group; n = 50), individuals with normal glucose levels expressing one islet autoantibody (Ab) (single Ab group; n = 26) or multiple autoantibodies (multiple Ab group; n = 12), and healthy controls (control group; n = 43). An in silico analysis was performed to identify potential target genes of these miRNAs and to delineate enriched pathways. The relative expression of serum miR-101-3p was approximately three times higher in the multiple Ab and T1D groups than that in the single Ab and control groups (p < 0.0001). When considering all groups together, miR-101-3p expression was positively correlated with the level of islet autoantibodies GADA (r = 0.267; p = 0.0027) and IA-2A (r = 0.291; p = 0.001), and the expression of the miRNA was not correlated with levels of ZnT8A (r = 0.125; p = 0.183). miR-101-3p expression did not correlate with HbA1c (r = 0.178; p = 0.052) or glucose levels (r = 0.177; p = 0.051). No significant differences were observed in miR-204-5p expression among the analyzed groups. Computational analysis of the miR-101-3p target gene pathways indicated a potential activation of the HGF/c-Met, Ephrin receptor, and STAT3 signaling pathways. Our study demonstrated that the circulating levels of miR-101-3p are higher in T1D patients and in individuals with normal glucose levels, testing positive for multiple autoantibodies, indicating that miR-101-3p precedes loss of glucose homeostasis. The pathogenic role of miR-101-3p in T1D may involve multiple molecular pathways.


Assuntos
Autoanticorpos/sangue , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , MicroRNAs/sangue , Autoanticorpos/imunologia , Autoantígenos/imunologia , Diabetes Mellitus Tipo 1/sangue , Humanos , Ilhotas Pancreáticas/imunologia , MicroRNAs/imunologia
15.
Eur Arch Otorhinolaryngol ; 276(11): 3247-3249, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31363902

RESUMO

PURPOSE: The pathogenesis of persistent allergic rhinitis with chronic and refractory nasal obstruction is still unknown. Inflammation and tissue remodeling are known to play a role, but this has not been studied thoroughly. The purpose of this study is to identify the profile of gene expression of inflammatory and remodeling markers in nasal mucosa of patients with PAR and chronic obstruction. METHODS: After informed consent, we obtained nasal mucosa tissue from five aeroallergen-sensitized PAR patients undergoing anterior turbinectomy, and control non-sensitized individuals undergoing cerebrospinal fluid fistula repair or rhinoplasty. We assessed the expression of 34 genes related to inflammation and tissue remodeling using the real-time polymerase chain reaction (qPCR) to quantify each mRNA. RESULTS: IL-4 mRNA was upregulated in nasal mucosa of all five patients; CCR3, CCR8 and Eotaxin-2 were upregulated in four out of five patient samples; while IL-5 and IL-13 were upregulated in two of them. TGF-ß1 was not upregulated in PAR samples. mRNA from metalloproteinases MMP-7, MMP13 and MMP15 were upregulated in three out of five samples. Our results indicate a typical mRNA expression profile of the infiltrating inflammatory Th2 cells and eosinophils, combined with altered gene expression of remodeling-related proteins in stromal cells from the mucosa. CONCLUSION: Prolonged allergen challenge can lead to persistent upregulation of genes for inflammatory mediators such as IL-4 Th2/eosinophil cytokines, chemokines and receptors, which may play an important role in maintaining PAR with chronic nasal obstruction. Our findings may have therapeutic implications, including the use of anti-IL4, -CCR3 or -MMP therapy to ameliorate the condition.


Assuntos
Mediadores da Inflamação , Interleucina-4/análise , Metaloproteases/análise , Mucosa Nasal/imunologia , Obstrução Nasal , Receptores CCR3/análise , Rinite Alérgica/imunologia , Adulto , Biomarcadores/análise , Feminino , Perfilação da Expressão Gênica , Humanos , Mediadores da Inflamação/análise , Mediadores da Inflamação/classificação , Masculino , Pessoa de Meia-Idade , Obstrução Nasal/etiologia , Obstrução Nasal/imunologia , Rinite Alérgica/complicações , Rinite Alérgica/patologia , Tempo , Regulação para Cima
16.
Front Immunol ; 10: 843, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31105693

RESUMO

Cellular immune responses are implicated in resistance to HIV and have been considered for the development of an effective vaccine. Despite their safety profile, subunit vaccines need to be delivered combined with an adjuvant. In the last years, in vivo antigen targeting to dendritic cells (DCs) using chimeric monoclonal antibodies (mAb) against the DC endocytic receptor DEC205/CD205 was shown to support long-term T cell immunity. Here, we evaluated the ability of different adjuvants to modulate specific cellular immune response when eight CD4+ HIV-derived epitopes (HIVBr8) were targeted to DEC205+ DCs in vivo. Immunization with two doses of αDECHIVBr8 mAb along with poly(I:C) induced Th1 cytokine production and higher frequency of HIV-specific polyfunctional and long-lived T cells than MPL or CpG ODN-assisted immunization. Although each adjuvant elicited responses against the 8 epitopes present in the vaccine, the magnitude of the T cell response was higher in the presence of poly(I:C). Moreover, poly(I:C) up regulated the expression of costimulatory molecules in both cDC1 and cDC2 DCs subsets. In summary, the use of poly(I:C) in a vaccine formulation that targets multiple epitopes to the DEC205 receptor improved the potency and the quality of HIV-specific responses when compared to other vaccine-adjuvant formulations. This study highlights the importance of the rational selection of antigen/adjuvant combination to potentiate the desired immune responses.


Assuntos
Vacinas contra a AIDS/imunologia , Células Dendríticas/imunologia , Epitopos/imunologia , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , HIV/imunologia , Poli I-C , Linfócitos T/imunologia , Adjuvantes Imunológicos , Animais , Antígenos CD/metabolismo , Biomarcadores , Citocinas/metabolismo , Células Dendríticas/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Imunidade Celular , Imunofenotipagem , Ativação Linfocitária , Camundongos , Poli I-C/imunologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Linfócitos T/metabolismo
17.
Front Immunol ; 10: 740, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31073299

RESUMO

Background: Operational tolerance (OT) is a state of graft functional stability that occurs after at least 1 year of immunosuppressant withdrawal. MicroRNAs (microRNA) are small non-coding RNAs that downregulate messenger RNA/protein expression of innumerous molecules and are critical for homeostasis. We investigated whether OT in kidney transplantation displays a differential microRNA profile, which would suggest that microRNAs participate in Operational Tolerance mechanisms, and may reveal potential molecular pathways. Methods: We first compared serum microRNA in OT (n = 8) with chronic rejection (CR) (n = 5) and healthy individuals (HI) (n = 5), using a 768-microRNA qPCR-panel. We used the Thermo Fisher Cloud computing platform to compare the levels of microRNAs in the OT group in relation to the other study groups. We performed validation experiments for miR-885-5p, by q-PCR, in a larger number of study subjects (OT = 8, CR = 12, HI = 12), as individual samples. Results: We detected a differential microRNA profile in OT vs. its opposing clinical outcome-CR-suggesting that microRNAs may integrate transplantation tolerance mechanisms. Some miRNAs were detected at higher levels in OT: miR-885-5p, miR-331-3p, miR-27a-5p vs. CR; others, we found at lower levels: miR-1233-3p, miR-572, miR-638, miR-1260a. Considering highly predicted/experimentally demonstrated targets of these miRNAs, bioinformatics analysis revealed that the granzyme B, and death receptor pathways are dominant, suggesting that cell death regulation integrates transplantation tolerance mechanisms. We confirmed higher miR-885-5p levels in OT vs. CR, and vs. HI, in a larger number of subjects. Conclusions: We propose that epigenetics mechanisms involving microRNAs may integrate human transplantation tolerance mechanisms, and regulate key members of the cell death/survival signaling. miR-885-5p could favor cell survival in OT by diminishing the levels of CRADD/RAIDD and CASP3. Nonetheless, given the nature of any complex phenomenon in humans, only cumulative data will help to determine whether this microRNA differential profile may be related to the cause or consequence of operational tolerance.


Assuntos
Sobrevivência Celular/genética , Tolerância Imunológica/genética , MicroRNAs/genética , Adulto , Biologia Computacional/métodos , Regulação para Baixo/genética , Feminino , Perfilação da Expressão Gênica/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real/métodos
18.
J Nucl Cardiol ; 26(5): 1569-1579, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-29392628

RESUMO

BACKGROUND: Myocardial perfusion defects (MPD) due to coronary microvascular dysfunction is frequent in chronic Chagas cardiomyopathy (CCC) and may be involved with development of myocardial damage. We investigated whether MPD precedes left ventricular systolic dysfunction and tested the hypothesis that prolonged use of dipyridamole (DIPY) could reduce MPD in an experimental model of CCC in hamsters. METHODS AND RESULTS: We investigated female hamsters 6-months after T. cruzi infection (baseline condition) and control animals, divided into T. cruzi-infected animals treated with DIPY (CH + DIPY) or placebo (CH + PLB); and uninfected animals treated with DIPY (CO + DIPY) or placebo (CO + PLB). The animals were submitted to echocardiogram and rest SPECT-Sestamibi-Tc99m myocardial perfusion scintigraphy. Next, the animals were treated with DIPY (4 mg/kg bid, intraperitoneal) or saline for 30 days, and reevaluated with the same imaging methods. At baseline, the CH + PLB and CH + DIPY groups showed larger areas of perfusion defect (13.2 ± 13.2% and 17.3 ± 13.2%, respectively) compared with CO + PLB and CO + DIPY (3.8 ± 2.2% e 3.5 ± 2.7%, respectively), P < .05. After treatment, we observed: reduction of perfusion defects only in the CH + DIPY group (17.3 ± 13.2% to 6.8 ± 7.6%, P = .001) and reduction of LVEF in CH + DIPY and CH + PLB groups (from 65.3 ± 9.0% to 53.6 ± 6.9% and from 69.3 ± 5.0% to 54.4 ± 8.6%, respectively, P < .001). Quantitative histology revealed greater extents of inflammation and interstitial fibrosis in both Chagas groups, compared with control group (P < .001), but no difference between Chagas groups (P > .05). CONCLUSIONS: The prolonged use of DIPY in this experimental model of CCC has reduced the rest myocardial perfusion defects, supporting the notion that those areas correspond to viable hypoperfused myocardium.


Assuntos
Cardiomiopatia Chagásica/diagnóstico por imagem , Cardiomiopatia Chagásica/tratamento farmacológico , Dipiridamol/administração & dosagem , Coração/diagnóstico por imagem , Animais , Cricetinae , Modelos Animais de Doenças , Ecocardiografia , Feminino , Ventrículos do Coração/diagnóstico por imagem , Imagem de Perfusão do Miocárdio , Perfusão , Tecnécio Tc 99m Sestamibi , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X , Trypanosoma cruzi , Vasodilatadores/administração & dosagem
19.
Front Immunol ; 9: 2791, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30559742

RESUMO

Chagas disease is caused by infection with the protozoan Trypanosoma cruzi and affects over 8 million people worldwide. In spite of a powerful innate and adaptive immune response in acute infection, the parasite evades eradication, leading to a chronic persistent infection with low parasitism. Chronically infected subjects display differential patterns of disease progression. While 30% develop chronic Chagas disease cardiomyopathy (CCC)-a severe inflammatory dilated cardiomyopathy-decades after infection, 60% of the patients remain disease-free, in the asymptomatic/indeterminate (ASY) form, and 10% develop gastrointestinal disease. Infection of genetically deficient mice provided a map of genes relevant for resistance to T. cruzi infection, leading to the identification of multiple genes linked to survival to infection. These include pathogen resistance genes (PRG) needed for intracellular parasite destruction, and genes involved in disease tolerance (protection against tissue damage and acute phase death-DTG). All identified DTGs were found to directly or indirectly inhibit IFN-γ production or Th1 differentiation. We hypothesize that the absolute need for DTG to control potentially lethal IFN-γ PRG activity leads to T. cruzi persistence and establishment of chronic infection. IFN-γ production is higher in CCC than ASY patients, and is the most highly expressed cytokine in CCC hearts. Key DTGs that downmodulate IFN-γ, like IL-10, and Ebi3/IL27p28, are higher in ASY patients. Polymorphisms in PRG and DTG are associated with differential disease progression. We thus hypothesize that ASY patients are disease tolerant, while an imbalance of DTG and IFN-γ PRG activity leads to the inflammatory heart damage of CCC.


Assuntos
Cardiomiopatia Chagásica/imunologia , Doença de Chagas/imunologia , Tolerância Imunológica/imunologia , Trypanosoma cruzi/imunologia , Progressão da Doença , Coração/parasitologia , Humanos , Interferon gama/imunologia , Interleucina-10/imunologia , Células Th1/imunologia , Células Th1/parasitologia
20.
J Nucl Med ; 59(9): 1430-1436, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29700129

RESUMO

Altered myocardial perfusion is a common finding in chronic Chagas cardiomyopathy (CCC), but its underlying histologic changes have not been elucidated. We investigated the occurrence of myocardial perfusion defects (MPDs) and the correlated regional changes to histology in an experimental model of CCC in hamsters. Methods: Female Syrian hamsters (n = 34) were infected with 3.5 × 104 to 105 trypomastigote forms of Trypanosoma cruzi, Y strain, and 6-10 mo afterward underwent in vivo imaging including resting 99mTc-sestamibi SPECT, segmental and global left ventricular function assessment using 2-dimensional echocardiography, and 18F-FDG PET for evaluation of myocardial viability. Histologic analysis included quantification of fibrosis, inflammatory infiltration, and the diameter and density of myocardial microcirculation. Results: MPDs were present in 17 (50%) of the infected animals. Histologic analysis revealed no transmural scar in segments with an MPD, and normal or mildly reduced 18F-FDG uptake, indicating viable myocardium. Infected animals with an MPD, in comparison to infected animals without an MPD and control animals, showed a lower left ventricular ejection fraction (P = 0.012), a higher wall motion score index (P = 0.004), and a higher extent of inflammatory infiltration (P = 0.018) but a similar extent of fibrosis (P = 0.15) and similar microvascular diameter and density (P > 0.05). Segments with an MPD (n = 65), as compared with normally perfused regions in the same animal (n = 156), showed a higher wall motion score index (P = 0.005) but a similar extent of inflammatory infiltration, a similar extent of fibrosis, and a similar microvascular diameter and density. Conclusion: Resting MPDs are frequent in experimental CCC and are associated with myocardial inflammation but do not designate scar tissue, corresponding to regions with metabolically viable myocardium.


Assuntos
Cardiomiopatia Chagásica/fisiopatologia , Circulação Coronária , Animais , Cardiomiopatia Chagásica/diagnóstico por imagem , Cardiomiopatia Chagásica/patologia , Doença Crônica , Cricetinae , Modelos Animais de Doenças , Feminino , Fluordesoxiglucose F18 , Microvasos/diagnóstico por imagem , Microvasos/fisiopatologia , Imagem de Perfusão do Miocárdio , Miocárdio/patologia , Tomografia por Emissão de Pósitrons , Sístole/fisiologia , Sobrevivência de Tecidos , Disfunção Ventricular Esquerda/fisiopatologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...