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1.
Sci Rep ; 7(1): 17990, 2017 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-29269773

RESUMO

Chagas disease, caused by the parasite Trypanosoma cruzi, is endemic in Latin America. Its acute phase is associated with high parasitism, myocarditis and profound myocardial gene expression changes. A chronic phase ensues where 30% develop severe heart lesions. Mouse models of T. cruzi infection have been used to study heart damage in Chagas disease. The aim of this study was to provide an interactome between miRNAs and their targetome in Chagas heart disease by integrating gene and microRNA expression profiling data from hearts of T. cruzi infected mice. Gene expression profiling revealed enrichment in biological processes and pathways associated with immune response and metabolism. Pathways, functional and upstream regulator analysis of the intersections between predicted targets of differentially expressed microRNAs and differentially expressed mRNAs revealed enrichment in biological processes and pathways such as IFNγ, TNFα, NF-kB signaling signatures, CTL-mediated apoptosis, mitochondrial dysfunction, and Nrf2-modulated antioxidative responses. We also observed enrichment in other key heart disease-related processes like myocarditis, fibrosis, hypertrophy and arrhythmia. Our correlation study suggests that miRNAs may be implicated in the pathophysiological processes taking place the hearts of acutely T. cruzi-infected mice.


Assuntos
Doença de Chagas/metabolismo , MicroRNAs/fisiologia , Trypanosoma cruzi/metabolismo , Animais , Doença de Chagas/imunologia , Doença de Chagas/patologia , Feminino , Redes e Vias Metabólicas , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , Transcriptoma
2.
J Infect Dis ; 216(6): 771-775, 2017 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-28934429

RESUMO

Cerebral malaria, a reversible encephalopathy affecting young children, is a medical emergency requiring urgent clinical assessment and treatment. We performed a whole-transcriptomic analysis of blood samples from Malian children with cerebral or uncomplicated malaria. We focused on transcripts from pathways for which dysfunction has been associated with neurodegenerative disorders. We found that SNCA, SIAH2, UBB, HSPA1A, TUBB2A, and PINK1 were upregulated (fold-increases, ≥2.6), whereas UBD and PSMC5 were downregulated (fold-decreases, ≤4.39) in children with cerebral malaria, compared with those with uncomplicated malaria. These findings provide the first evidence for pathogenic mechanisms common to human cerebral malaria and neurodegenerative disorders.


Assuntos
Malária Cerebral/genética , Malária Falciparum/genética , Doenças Neurodegenerativas/genética , ATPases Associadas a Diversas Atividades Celulares , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Criança , Pré-Escolar , Regulação para Baixo , Feminino , Perfilação da Expressão Gênica , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Humanos , Proteínas com Domínio LIM/genética , Proteínas com Domínio LIM/metabolismo , Leucócitos Mononucleares/parasitologia , Malária Cerebral/diagnóstico , Malária Falciparum/diagnóstico , Masculino , Doenças Neurodegenerativas/diagnóstico , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Plasmodium falciparum , Estudos Prospectivos , Complexo de Endopeptidases do Proteassoma , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Reprodutibilidade dos Testes , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo , Ubiquitina/genética , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinas/genética , Ubiquitinas/metabolismo , Regulação para Cima , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo
3.
Int J Parasitol ; 47(13): 823-830, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28739251

RESUMO

MicroRNAs (miRNAs) are short, non-coding RNAs that repress the translation of target gene transcripts. They have been implicated in various activities such as cell proliferation, survival, differentiation, migration and metabolism. We report here the first known miRNome and transcriptome analysis of human livers displaying advanced fibrosis due to Schistosoma japonicum infection. We present evidence that hsa-miR-150-5p, hsa-miR-10a-5p, hsa-miR-199a-3p, hsa-miR-4521, hsa-miR-222/221, hsa-miR-663b and hsa-miR-143-3p (associated without correction) play an important role in hepatic fibrosis by acting on metabolism, organization of the extracellular matrix proteins, lipid mobilization and limitation of oxidative damage stress.


Assuntos
Cirrose Hepática/genética , MicroRNAs/fisiologia , Esquistossomose Japônica/patologia , Adulto , Animais , Estudos de Casos e Controles , Regulação para Baixo , Feminino , Expressão Gênica , Humanos , Fígado/química , Fígado/patologia , Cirrose Hepática/etiologia , Cirrose Hepática/parasitologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Transcrição Reversa , Schistosoma japonicum/fisiologia , Esquistossomose Japônica/complicações , Esquistossomose Japônica/genética , Regulação para Cima , Adulto Jovem
4.
Clin Infect Dis ; 65(7): 1103-1111, 2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-28575239

RESUMO

Background: Chagas disease, caused by the protozoan Trypanosoma cruzi, is endemic in Latin America and affects 10 million people worldwide. Approximately 12000 deaths attributable to Chagas disease occur annually due to chronic Chagas disease cardiomyopathy (CCC), an inflammatory cardiomyopathy presenting with heart failure and arrythmia; 30% of infected subjects develop CCC years after infection. Genetic mechanisms play a role in differential progression to CCC, but little is known about the role of epigenetic modifications in pathological gene expression patterns in CCC patients' myocardium. DNA methylation is the most common modification in the mammalian genome. Methods: We investigated the impact of genome-wide cardiac DNA methylation on global gene expression in myocardial samples from end-stage CCC patients, compared to control samples from organ donors. Results: In total, 4720 genes were differentially methylated between CCC patients and controls, of which 399 were also differentially expressed. Several of them were related to heart function or to the immune response and had methylation sites in their promoter region. Reporter gene and in silico transcription factor binding analyses indicated promoter methylation modified expression of key genes. Among those, we found potassium channel genes KCNA4 and KCNIP4, involved in electrical conduction and arrythmia, SMOC2, involved in matrix remodeling, as well as enkephalin and RUNX3, potentially involved in the increased T-helper 1 cytokine-mediated inflammatory damage in heart. Conclusions: Results support that DNA methylation plays a role in the regulation of expression of pathogenically relevant genes in CCC myocardium, and identify novel potential disease pathways and therapeutic targets in CCC.


Assuntos
Cardiomiopatia Chagásica/genética , Doença de Chagas/genética , Metilação de DNA/genética , Adolescente , Adulto , Idoso , Cardiomiopatia Chagásica/parasitologia , Doença de Chagas/parasitologia , Doença Crônica , Impressões Digitais de DNA/métodos , Feminino , Expressão Gênica/genética , Coração/parasitologia , Humanos , Inflamação/genética , Inflamação/parasitologia , Masculino , Pessoa de Meia-Idade , Miocárdio/metabolismo , Canais de Potássio/genética , Regiões Promotoras Genéticas/genética , Trypanosoma cruzi/patogenicidade , Adulto Jovem
5.
J Infect Dis ; 214(1): 161-5, 2016 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-26951817

RESUMO

Long noncoding RNAs (lncRNAs) modulate gene expression at the epigenetic, transcriptional, and posttranscriptional levels. Dysregulation of the lncRNA known as myocardial infarction-associated transcript (MIAT) has been associated with myocardial infarction. Chagas disease causes a severe inflammatory dilated chronic cardiomyopathy (CCC). We investigated the role of MIAT in CCC. A whole-transcriptome analysis of heart biopsy specimens and formalin-fixed, paraffin-embedded samples revealed that MIAT was overexpressed in patients with CCC, compared with subjects with noninflammatory dilated cardiomyopathy and controls. These results were confirmed in a mouse model. Results suggest that MIAT is a specific biomarker of CCC.


Assuntos
Doença de Chagas/complicações , Doença de Chagas/genética , Perfilação da Expressão Gênica , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/genética , RNA Longo não Codificante , Animais , Doença de Chagas/fisiopatologia , Feminino , Humanos , Masculino , Camundongos , Fatores de Transcrição
7.
PLoS Negl Trop Dis ; 10(1): e0004306, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26731721

RESUMO

Schistosoma eggs cause chronic liver inflammation and a complex disease characterized by hepatic fibrosis (HF) and splenomegaly (SplM). FOXP3+ Tregs could regulate inflammation, but it is unclear where these cells are produced and what roles they play in human schistosomiasis. We investigated blood and spleen FOXP3+ Tregs in Chinese fishermen with lifelong exposure to Schistosoma japonicum and various degrees of liver and spleen disease. FOXP3+ Tregs accounted for 4.3% of CD4+ T cells and 41.2% of FOXP3+CD4+ T cells; they could be divided into CD45RA-FOXP3hi effector (eTregs) and CD45RA+FOXP3low naive Tregs. Blood Treg levels were high in severe HF (+1.3; p = 0.004) and in SplM (+1.03, p = 0.03). Multivariate regression showed that severe HF (+0.85, p = 0.01) and SplM (+0.97; p = 0.05) were independently associated with the higher proportion of Tregs in the blood. This effect was mostly due to an increase in the proportion of eTregs in the blood of HF+++ (+0.9%; p = 0.04) and SplM (+0.9%; p = 0.04) patients. The proportion of eTregs expressing CXCR3 in the blood was lower in the HF+++ patients (37.4 +/- 5.9%) than in those with milder fibrosis (51.7 ± 2%; p = 0.009), whereas proportion were similar for cells expressing CD25hi, CCR7, and CTLA-4. Splenectomy improves symptoms and was associated with decreases in blood FOXP3+ Treg (-2.5; p<0.001) and eTreg (-1.3; p = 0.03) levels. SplM spleens contained a high proportion of eTregs with CXCR3, CCR5 and CTLA4 upregulation and CCR7 downregulation. This, and the strong expression of ligands of CXCR3 and CCR5 in the liver (n = 8) but not in the spleen suggested that spleen eTregs migrated to Th1-infiltrated liver tissues. Such migration may be attenuated in hepatosplenic patients due to lower levels of CXCR3 expression on Tregs (p = 0.009). Thus, higher blood Treg levels are associated with severe liver disease and splenomegaly. Our data are consistent with the hypothesis that the spleen is a major source of Tregs in subjects with splenomegaly. In most cases, Tregs migrate to the Th1-infiltrated liver and the lower levels of CXCR3+ Tregs in the blood of patients with severe schistosomiasis suggest that decreases in Treg migration sites of inflammation may aggravate the disease.


Assuntos
Fatores de Transcrição Forkhead/análise , Cirrose Hepática/patologia , Esquistossomose Japônica/patologia , Esplenomegalia/patologia , Subpopulações de Linfócitos T/química , Subpopulações de Linfócitos T/imunologia , Linfócitos T Reguladores/imunologia , Adulto , Idoso , Animais , Antígenos CD/análise , China , Estudos de Coortes , Humanos , Imunofenotipagem , Fígado/patologia , Cirrose Hepática/complicações , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional , Baço/patologia , Esplenomegalia/complicações , Linfócitos T Reguladores/química
8.
Infect Immun ; 84(2): 590-7, 2016 02.
Artigo em Inglês | MEDLINE | ID: mdl-26667835

RESUMO

Cerebral malaria (CM) is a neurological complication of infection with Plasmodium falciparum that is partly caused by cytokine-mediated inflammation. It is not known whether interleukin-17 (IL-17) cytokines, which regulate inflammation, control the development of CM. To evaluate the involvement of IL-17 cytokines in CM, we analyzed 46 common polymorphisms in IL17A, IL17F, and IL17RA (which encodes the common receptor chain of the members of the IL-17 family) in two independent African populations. A case-control study involving 115 Nigerian children with CM and 160 controls from the community (CC) showed that IL17F reference single nucleotide polymorphism (SNP) 6913472 (rs6913472) (P = 0.004; odds ratio [OR] = 3.12), IL17F rs4715291 (P = 0.004; OR = 2.82), IL17RA rs12159217 (P = 0.01; OR = 2.27), and IL17RA rs41396547 (P = 0.026; OR = 3.15) were independently associated with CM. A replication study was performed in 240 nuclear Malian family trios (two parents with one CM child). We replicated the association for 3 SNPs, IL17F rs6913472 (P = 0.03; OR = 1.39), IL17RA rs12159217 (P = 0.01; OR = 1.52), and IL17RA rs41396547 (P = 0.04; OR = 3.50). We also found that one additional SNP, IL17RA rs41433045, in linkage disequilibrium (LD) with rs41396547, was associated with CM in both Nigeria and Mali (P = 0.002; OR = 4.12 in the combined sample). We excluded the possibility that SNPs outside IL17F and IL17RA, in strong LD with the associated SNPs, could account for the observed associations. Furthermore, the results of a functional study indicated that the aggravating GA genotype of IL17F rs6913472 was associated with lower IL-17F concentrations. Our findings show for the first time that IL17F and IL17RA polymorphisms modulate susceptibility to CM and provide evidence that IL-17F protects against CM.


Assuntos
Interleucina-17/genética , Malária Cerebral/etnologia , Malária Cerebral/genética , Polimorfismo de Nucleotídeo Único , Receptores de Interleucina-17/genética , Adolescente , África/epidemiologia , Criança , Pré-Escolar , Simulação por Computador , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Genética Populacional , Genótipo , Humanos , Lactente , Interleucina-17/imunologia , Desequilíbrio de Ligação , Malária Cerebral/epidemiologia , Malária Cerebral/imunologia , Masculino , Receptores de Interleucina-17/imunologia
9.
Immunogenetics ; 67(5-6): 283-8, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25935236

RESUMO

We have previously found that children heterozygous for IL4 variable-number tandem repeat (VNTR) (rs8179190) or IL4-33 (rs2070874) variants were at risk for severe malaria (SM), whereas homozygous children were protected suggesting a complex genetic control. Hence, to dissect this complex genetic control of IL4 VNTR and IL4-33, we performed further investigation by conditional logistic regression analysis and found a strong interaction between both markers (p < 10(-6)). The best-fit model revealed three genotype combinations associated with different levels of SM risk. The highest risk (odds ratio (OR) = 4.8, 95% confidence interval (CI) = 2.0-11.5) was observed for subjects carrying at least one copy of both IL4-33 allele T and IL4 VNTR allele 1, who exhibited higher interleukin (IL)-4 plasma levels (p = 0.007). Children homozygous for IL4 VNTR allele 2 had a lower SM risk as well as lower IL-4 plasma levels. Our findings indicate that the genetic interaction between these two IL-4 variants is a key factor of SM susceptibility, probably because of its direct role in IL-4 regulation.


Assuntos
Predisposição Genética para Doença , Genótipo , Interleucina-4/genética , Malária/genética , Feminino , Estudos de Associação Genética , Genética Populacional , Humanos , Interleucina-4/sangue , Malária/sangue , Malária/patologia , Masculino , Mali , Repetições Minissatélites/genética , Polimorfismo de Nucleotídeo Único , Fatores de Risco
11.
Cytokine ; 73(1): 79-83, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25743241

RESUMO

BACKGROUND: Chronic Chagas Disease cardiomyopathy (CCC), a life-threatening inflammatory dilated cardiomyopathy, affects 30% of the approximately 8 million patients infected by Trypanosoma cruzi, the rest of the infected subjects remaining asymptomatic (ASY). The Th1 T cell-rich myocarditis plays a pivotal role in CCC pathogenesis. Local expression of IL-18 in CCC myocardial tissue has recently been described. IL-18 could potentially amplify the process by inducing increased expression of IFN-γ which in turn can increase the production of IL-18, thereby creating a positive feedback mechanism. In order to assess the contribution of the IL-18 to susceptibility to Chronic Chagas Disease, we investigated the association between a single nucleotide polymorphism (SNP) located in the IL-18 gene with the risk of developing Chagas cardiomyopathy. METHODS AND RESULTS: We analyzed the rs2043055 marker in the IL18 gene in a cohort of Chagas disease cardiomyopathy patients (n=849) and asymptomatic subjects (n=202). We found a significant difference in genotype frequencies among moderate and severe CCC patients with ventricular dysfunction. CONCLUSIONS: Our analysis suggests that the IL18 rs2043055 polymorphism- or a SNP in tight linkage disequilibrium with it- may contribute to modulating the Chagas cardiomyopathy outcome.


Assuntos
Cardiomiopatia Chagásica/genética , Predisposição Genética para Doença , Interleucina-18/genética , Polimorfismo de Nucleotídeo Único/genética , Estudos de Casos e Controles , Cardiomiopatia Chagásica/fisiopatologia , Doença Crônica , Estudos de Coortes , Feminino , Estudos de Associação Genética , Humanos , Masculino , Volume Sistólico
12.
J Immunol ; 194(6): 2664-72, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25672756

RESUMO

The outcome of Leishmania infections varies substantially, depending on the host and the parasite strain; infection may be asymptomatic or cause mild or severe skin ulcers (cutaneous leishmaniasis [CL]), limited or disseminated lesions, or lethal visceral disease. We previously reported an association between IL-2R mutations and susceptibility to visceral leishmaniasis in children infected with Leishmania donovani. In the present study, we evaluated the possible role of IL-2 signaling in human CL. We first showed that the transcripts of several genes of the IL-2 pathway were abundant in skin lesions caused by Leishmania braziliensis. We then carried out a genetic analysis, focusing on major genes of the IL-2 pathway. We used a family-based approach and found that polymorphisms of several genes appeared to be associated with CL in a Brazilian population. Moreover, two polymorphisms of the IL2RA gene were significantly and independently associated with CL. We confirmed this result in a second Brazilian sample (also exposed to L. braziliensis) and in Iranians infected with Leishmania tropica: IL2RA rs10905669 T (Pcombined = 6 × 10(-7)) and IL2RA rs706778 T (Pcombined = 2 × 10(-9)) were associated with greater susceptibility to lesion development. These alleles were also correlated with a poor IFN-γ response and poor FOXP3(+) regulatory T cell activation. Thus, IL-2 plays a crucial role in protection against the cutaneous ulcers caused by Leishmania, and the IL-2 pathway is a potential target for strategies aiming to control Leishmania-related diseases.


Assuntos
Subunidade alfa de Receptor de Interleucina-2/imunologia , Interleucina-2/imunologia , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Polimorfismo de Nucleotídeo Único/imunologia , Adolescente , Adulto , Criança , Feminino , Fatores de Transcrição Forkhead/imunologia , Fatores de Transcrição Forkhead/metabolismo , Perfilação da Expressão Gênica , Frequência do Gene , Predisposição Genética para Doença/genética , Genótipo , Interações Hospedeiro-Parasita/imunologia , Humanos , Interferon gama/imunologia , Interleucina-2/genética , Subunidade alfa de Receptor de Interleucina-2/genética , Leishmania braziliensis/fisiologia , Leishmaniose Cutânea/genética , Leishmaniose Cutânea/parasitologia , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Polimorfismo de Nucleotídeo Único/genética , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Adulto Jovem
13.
Hepatology ; 61(4): 1321-31, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25476703

RESUMO

UNLABELLED: Interleukin (IL)-22 acts on epithelia, hepatocytes, and pancreatic cells and stimulates innate immunity, tissue protection, and repair. IL-22 may also cause inflammation and abnormal cell proliferation. The binding of IL-22 to its receptor is competed by IL-22 binding protein (IL-22BP), which may limit the deleterious effects of IL-22. The role of IL-22 and IL-22BP in chronic liver diseases is unknown. We addressed this question in individuals chronically infected with schistosomes or hepatitis C virus (HCV). We first demonstrate that schistosome eggs stimulate production of IL-22 transcripts and inhibit accumulation of IL22-BP transcripts in schistosome-infected mice, and that schistosome eggs selectively stimulate production of IL-22 in cultures of blood leukocytes from individuals chronically infected with Schistosoma japonicum. High IL-22 levels in cultures correlated with protection against hepatic fibrosis and portal hypertension. To test further the implication of IL-22/IL-22BP in hepatic disease, we analyzed common genetic variants of IL22RA2, which encodes IL-22BP, and found that the genotypes, AA, GG of rs6570136 (P = 0.003; odds ratio [OR] = 2), and CC, TT of rs2064501 (P = 0.01; OR = 2), were associated with severe fibrosis in Chinese infected with S. japonicum. We confirmed this result in Sudanese (rs6570136 GG [P = 0.0007; OR = 8.2], rs2064501 TT [P = 0.02; OR = 3.1]), and Brazilians (rs6570136 GG [P = 0.003; OR = 26], rs2064501 TC, TT (P = 0.03; OR = 11]) infected with S. mansoni. The aggravating genotypes were associated with high IL22RA2 transcripts levels. Furthermore, these same variants were also associated with HCV-induced fibrosis and cirrhosis (rs6570136 GG, GA [P = 0.007; OR = 1.7], rs2064501 TT, TC (P = 0.004; OR = 2.4]). CONCLUSIONS: These results provide strong evidence that IL-22 protects against and IL-22BP aggravates liver fibrosis and cirrhosis in humans with chronic liver infections. Thus, pharmacological modulation of IL-22 BP may be an effective strategy to limit cirrhosis.


Assuntos
Hepatite C Crônica/complicações , Interleucinas/fisiologia , Cirrose Hepática/etiologia , Receptores de Interleucina/fisiologia , Esquistossomose/complicações , Adulto , Animais , Feminino , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade
14.
Cytokine ; 73: 79-83, 2015. tab
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: ses-31265

RESUMO

Background: Chronic Chagas Disease cardiomyopathy (CCC), a life-threatening inflammatory dilated cardiomyopathy,affects 30% of the approximately 8 million patients infected by Trypanosoma cruzi, the restof the infected subjects remaining asymptomatic (ASY). The Th1 T cell-rich myocarditis plays a pivotalrole in CCC pathogenesis. Local expression of IL-18 in CCC myocardial tissue has recently been described.IL-18 could potentially amplify the process by inducing increased expression of IFN-c which in turn canincrease the production of IL-18, thereby creating a positive feedback mechanism. In order to assess thecontribution of the IL-18 to susceptibility to Chronic Chagas Disease, we investigated the associationbetween a single nucleotide polymorphism (SNP) located in the IL-18 gene with the risk of developingChagas cardiomyopathy.Methods and results: We analyzed the rs2043055 marker in the IL18 gene in a cohort of Chagas diseasecardiomyopathy patients (n = 849) and asymptomatic subjects (n = 202). We found a significant differencein genotype frequencies among moderate and severe CCC patients with ventricular dysfunction.Conclusions: Our analysis suggests that the IL18 rs2043055 polymorphism- or a SNP in tight linkagedisequilibrium with it- may contribute to modulating the Chagas cardiomyopathy outcome. (AU)


Assuntos
Doença de Chagas , Miocardite , Disfunção Ventricular
15.
J Exp Med ; 206(11): 2321-8, 2009 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-19822645

RESUMO

Abnormal fibrosis occurs during chronic hepatic inflammations and is the principal cause of death in hepatitis C virus and schistosome infections. Hepatic fibrosis (HF) may develop either slowly or rapidly in schistosome-infected subjects. This depends, in part, on a major genetic control exerted by genes of chromosome 6q23. A gene (connective tissue growth factor [CTGF]) is located in that region that encodes a strongly fibrogenic molecule. We show that the single nucleotide polymorphism (SNP) rs9402373 that lies close to CTGF is associated with severe HF (P = 2 x 10(-6); odds ratio [OR] = 2.01; confidence interval of OR [CI] = 1.51-2.7) in two Chinese samples, in Sudanese, and in Brazilians infected with either Schistosoma japonicum or S. mansoni. Furthermore, SNP rs12526196, also located close to CTGF, is independently associated with severe fibrosis (P = 6 x 10(-4); OR = 1.94; CI = 1.32-2.82) in the Chinese and Sudanese subjects. Both variants affect nuclear factor binding and may alter gene transcription or transcript stability. The identified variants may be valuable markers for the prediction of disease progression, and identify a critical step in the development of HF that could be a target for chemotherapy.


Assuntos
Fator de Crescimento do Tecido Conjuntivo/genética , Predisposição Genética para Doença , Cirrose Hepática/genética , Cirrose Hepática/parasitologia , Polimorfismo de Nucleotídeo Único/genética , Esquistossomose/complicações , Esquistossomose/genética , Grupo com Ancestrais do Continente Africano/genética , Agricultura , Grupo com Ancestrais Nativos do Continente Americano/genética , Animais , Grupo com Ancestrais do Continente Asiático/genética , Brasil , Linhagem Celular , China , Ensaio de Desvio de Mobilidade Eletroforética , Pesqueiros , Humanos , Cirrose Hepática/complicações , Proteínas Nucleares , Ligação Proteica , Estabilidade de RNA , Schistosoma/fisiologia , Esquistossomose/parasitologia , Sudão , Transcrição Genética , Recursos Humanos
16.
J Infect Dis ; 200(10): 1530-9, 2009 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-19835477

RESUMO

BACKGROUND: Severe malaria (SM) due to Plasmodium falciparum causes millions of child deaths in sub-Saharan Africa. It comprises a variety of clinical disorders, including cerebral malaria (CM) and severe anemia (SA). In previous work, we have shown that interferon gamma and interleukin 12 protect against CM. Here, we investigated whether interleukin 4 (IL-4) aggravates the risk of severe disease. METHODS: We prospectively recruited children with CM (n = 240), SA (n = 101), and uncomplicated malaria (UM) (n = 42) in Bamako, Mali, and measured IL-4 production in plasma by enzyme-linked immunosorbent assay. We then assessed the influence of 11 polymorphisms on predisposition to SM by the family-based association test (FBAT). RESULTS: IL-4 concentrations were higher in children with CM than in children with UM during malaria (P = .003). FBAT analyses showed that the most significant association was between the IL4 variable-number tandem repeat (VNTR) 1/2 genotype and SM (P < .001); an association was also observed for IL4 -33 C/T, rs2243267 G/C, rs2243268 C/A, and rs2243282 C/A (P < .05). Interestingly, we found that the plasma concentration of IL-4 was higher in subjects with the IL4 VNTR 1/2 or 1/1 genotype than with the IL4 VNTR 2/2 genotype (P = .003). CONCLUSIONS: These results support the view that IL-4 may be a risk factor for SM. IL-4 may aggravate the disease by interfering with type 1 T helper cell differentiation or by promoting local inflammation at sites of parasite sequestration.


Assuntos
Interleucina-4/genética , Malária Cerebral/genética , Malária Falciparum/genética , Repetições Minissatélites/genética , Polimorfismo de Nucleotídeo Único/genética , Criança , Pré-Escolar , Feminino , Genótipo , Humanos , Lactente , Interleucina-4/sangue , Malária Cerebral/imunologia , Malária Falciparum/imunologia , Masculino
17.
J Clin Invest ; 119(8): 2379-87, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19620772

RESUMO

IL-17 and IL-22 have been shown to increase protection against certain bacteria and fungal pathogens in experimental models. However, no human studies have demonstrated a crucial role of IL-17 and IL-22 in protection against infections. We show here that Leishmania donovani, which can cause the lethal visceral disease Kala Azar (KA), stimulates the differentiation of Th17 cells, which produce IL-17, IL-22, and IFN-gamma. Analysis of Th1, Th2, and Th17 cytokine responses by cultured PBMCs from individuals in a cohort of subjects who developed KA or were protected against KA during a severe outbreak showed that IL-17 and IL-22 were strongly and independently associated with protection against KA. Our results suggest that, along with Th1 cytokines, IL-17 and IL-22 play complementary roles in human protection against KA, and that a defect in Th17 induction may increase the risk of KA.


Assuntos
Interleucina-17/fisiologia , Interleucinas/fisiologia , Leishmaniose Visceral/imunologia , Animais , Humanos , Interleucina-1beta/biossíntese , Interleucina-23/biossíntese , Interleucina-6/biossíntese , Leucócitos Mononucleares/imunologia , Células Th1/imunologia , Células Th2/imunologia
18.
Hum Mol Genet ; 17(14): 2190-5, 2008 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-18413324

RESUMO

The role of the Th1 pathway in the pathogenesis of severe malaria is unclear. We recently reported that a polymorphism with increasing IFNG transcription is associated with protection against cerebral malaria (CM). Interleukin-12 is required for Th1 cell differentiation, which is characterized by the production of interferon-gamma. We investigated 21 markers in IL12-related genes, including IL12A and IL12B encoding the two IL-12 (IL12p70) subunits, IL12p35 and IL12p40. We performed a family-based association study using a total sample set of 240 nuclear families. The IL12Bpro polymorphism was associated with susceptibility to CM. The CTCTAA allele and the GC/CTCTAA genotype are over-transmitted to children with CM (P = 0.0002 and 0.00002, respectively). We estimated the odds ratio to be 2.11 for risk of CM in heterozygous children [(95% confidence interval, 1.49-2.99); P < 0.0001]. Although the CTCTAA allele had a dominant effect on CM susceptibility, this effect is much stronger in heterozygous children, consistent with the functional effects of this allele in a heterozygous form. Heterozygosity for this polymorphism has been associated with reduced expression of the gene encoding IL12p40 and a low level of IL12p70 production. These results, together with the findings from immunological studies of low interferon-gamma and IL-12 levels in CM, support a protective role for the Th1 pathway in CM.


Assuntos
Predisposição Genética para Doença , Subunidade p40 da Interleucina-12/genética , Malária Cerebral/genética , Regiões Promotoras Genéticas , Criança , Estudos de Coortes , Heterozigoto , Humanos , Subunidade p35 da Interleucina-12/genética , Razão de Chances , Polimorfismo Genético , Receptores de Interleucina-12/genética , Fator de Transcrição STAT4/genética
19.
Pediatr Infect Dis J ; 27(2): 130-5, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18174865

RESUMO

BACKGROUND: The population exposed to malaria within African cities has steadily increased. However, comprehensive data on life-threatening malaria features and risk factors in children from urban areas with seasonal malaria transmission, such as in Bamako (Mali), are lacking. METHODS: Children admitted to the Gabriel Touré Hospital in Bamako with severe malarial anemia (SMA) and/or cerebral malaria (CM) were prospectively included in the study. Indicators of either SMA or CM were analyzed using logistic regression; and death hazard ratios (HRs) were estimated through survival analysis. RESULTS: The study included 455 children: 66% presented with CM, 34% with SMA, 3% with hypoglycemia (HG); 5% with dehydration; 17% with respiratory distress (RD); 25% with splenomegaly; and 92% with hepatomegaly. The children with CM were older than those with SMA. CM was more often associated with dehydration, HG, and RD, whereas SMA was more often associated with splenomegaly. The overall case fatality rate was 16%, and 94% of the children who died had CM. HG [HR: 2.37; 95% confidence interval (CI): 1.04-5.39; P = 0.040], RD (HR: 4.23; 95% CI: 2.46-7.30; P < 10(-6)) and a deep coma with a Blantyre score of less than 3 (HR: 6.78, 95% CI: 2.43-18.91; P < 10(-3)), were all independent predictors of death. CONCLUSIONS: These findings delineate the patterns of severe malaria in children in a West African mesoendemic urban setting. They validate practicable prognostic indicators of life-threatening malaria for use in the limited facilities available in African health centers and provide a frame of reference for further research addressing life-threatening malaria in this setting.


Assuntos
Anemia/parasitologia , Malária Cerebral/epidemiologia , Adolescente , Criança , Pré-Escolar , Doenças Endêmicas , Feminino , Humanos , Lactente , Recém-Nascido , Malária Cerebral/mortalidade , Masculino , Mali/epidemiologia , Estudos Prospectivos , Fatores de Risco , Estações do Ano , População Urbana
20.
Infect Immun ; 74(12): 7040-2, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16982833

RESUMO

The hypothesis that tumor necrosis factor (TNF) aggravates malaria in children is supported by observations that TNF polymorphisms and high TNF levels have been associated with cerebral malaria. Nevertheless, severe malaria was not associated with polymorphisms located at positions -308A and -238A in the TNF alpha gene promoter or with a high TNF level in plasma in children from Bamako, Mali.


Assuntos
Predisposição Genética para Doença , Malária Falciparum/genética , Fator de Necrose Tumoral alfa/genética , Alelos , Animais , Criança , Feminino , Frequência do Gene , Humanos , Masculino , Mali , Plasmodium falciparum , Regiões Promotoras Genéticas/genética , Risco , Fator de Necrose Tumoral alfa/sangue
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