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1.
Malar J ; 21(1): 189, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35706028

RESUMO

BACKGROUND: Malaria is a significant parasitic infection, and human infection is mediated by mosquito (Anopheles) biting and subsequent transmission of protozoa (Plasmodium) to the blood. Carbonic anhydrases (CAs) are known to be highly expressed in the midgut and ectoperitrophic space of Anopheles gambiae. Transmembrane CAs (tmCAs) in Plasmodium may be potential vaccine candidates for the control and prevention of malaria. METHODS: In this study, two groups of transmembrane CAs, including α-CAs and one group of η-CAs were analysed by immunoinformatics and computational biology methods, such as predictions on transmembrane localization of CAs from Plasmodium spp., affinity and stability of different HLA classes, antigenicity of tmCA peptides, epitope and proteasomal cleavage of Plasmodium tmCAs, accessibility of Plasmodium tmCAs MHC-ligands, allergenicity of Plasmodium tmCAs, disulfide-bond of Plasmodium tmCAs, B cell epitopes of Plasmodium tmCAs, and Cell type-specific expression of Plasmodium CAs. RESULTS: Two groups of α-CAs and one group of η-CAs in Plasmodium spp. were identified to contain tmCA sequences, having high affinity towards MHCs, high stability, and strong antigenicity. All putative tmCAs were predicted to contain sequences for proteasomal cleavage in antigen presenting cells (APCs). CONCLUSIONS: The predicted results revealed that tmCAs from Plasmodium spp. can be potential targets for vaccination against malaria.


Assuntos
Anopheles , Anidrases Carbônicas , Malária , Plasmodium , Vacinas , Animais , Anopheles/metabolismo , Anidrases Carbônicas/química , Anidrases Carbônicas/metabolismo , Epitopos de Linfócito B , Humanos , Malária/prevenção & controle , Plasmodium falciparum/metabolismo , Vacinologia
2.
BMC Cardiovasc Disord ; 21(1): 126, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33673806

RESUMO

BACKGROUND: Genetic testing in hypertrophic cardiomyopathy (HCM) is a published guideline-based recommendation. The diagnostic yield of genetic testing and corresponding HCM-associated genes have been largely documented by single center studies and carefully selected patient cohorts. Our goal was to evaluate the diagnostic yield of genetic testing in a heterogeneous cohort of patients with a clinical suspicion of HCM, referred for genetic testing from multiple centers around the world. METHODS: A retrospective review of patients with a suspected clinical diagnosis of HCM referred for genetic testing at Blueprint Genetics was undertaken. The analysis included syndromic, myopathic and metabolic etiologies. Genetic test results and variant classifications were extracted from the database. Variants classified as pathogenic (P) or likely pathogenic (LP) were considered diagnostic. RESULTS: A total of 1376 samples were analyzed. Three hundred and sixty-nine tests were diagnostic (26.8%); 373 P or LP variants were identified. Only one copy number variant was identified. The majority of diagnostic variants involved genes encoding the sarcomere (85.0%) followed by 4.3% of diagnostic variants identified in the RASopathy genes. Two percent of diagnostic variants were in genes associated with a cardiomyopathy other than HCM or an inherited arrhythmia. Clinical variables that increased the likelihood of identifying a diagnostic variant included: an earlier age at diagnosis (p < 0.0001), a higher maximum wall thickness (MWT) (p < 0.0001), a positive family history (p < 0.0001), the absence of hypertension (p = 0.0002), and the presence of an implantable cardioverter-defibrillator (ICD) (p = 0.0004). CONCLUSION: The diagnostic yield of genetic testing in this heterogeneous cohort of patients with a clinical suspicion of HCM is lower than what has been reported in well-characterized patient cohorts. We report the highest yield of diagnostic variants in the RASopathy genes identified in a laboratory cohort of HCM patients to date. The spectrum of genes implicated in this unselected cohort highlights the importance of pre-and post-test counseling when offering genetic testing to the broad HCM population.


Assuntos
Cardiomiopatia Hipertrófica/diagnóstico , Testes Genéticos , Variação Genética , Adolescente , Adulto , Cardiomiopatia Hipertrófica/genética , Cardiomiopatia Hipertrófica/fisiopatologia , Criança , Pré-Escolar , Feminino , Marcadores Genéticos , Predisposição Genética para Doença , Humanos , Lactente , Masculino , Fenótipo , Valor Preditivo dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Adulto Jovem
3.
Infect Immun ; 83(4): 1431-42, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25624351

RESUMO

Tuberculosis is a chronic bacterial disease with a complex pathogenesis. An effective immunity against Mycobacterium tuberculosis requires both the innate and adaptive immune responses, including proper T helper (Th) type 1 cell function. FURIN is a proprotein convertase subtilisin/kexin (PCSK) enzyme, which is highly expressed in Th1 type cells. FURIN expression in T cells is essential for maintaining peripheral immune tolerance, but its role in the innate immunity and infections has remained elusive. Here, we utilized Mycobacterium marinum infection models in zebrafish (Danio rerio) to investigate how furin regulates host responses against mycobacteria. In steady-state furinAtd204e/+ fish reduced furinA mRNA levels associated with low granulocyte counts and elevated Th cell transcription factor expressions. Silencing furin genes reduced the survival of M. marinum-infected zebrafish embryos. A mycobacterial infection upregulated furinA in adult zebrafish, and infected furinAtd204e/+ mutants exhibited a proinflammatory phenotype characterized by elevated tumor necrosis factor a (tnfa), lymphotoxin alpha (lta) and interleukin 17a/f3 (il17a/f3) expression levels. The enhanced innate immune response in the furinAtd204e/+ mutants correlated with a significantly decreased bacterial burden in a chronic M. marinum infection model. Our data show that upregulated furinA expression can serve as a marker for mycobacterial disease, since it inhibits early host responses and consequently promotes bacterial growth in a chronic infection.


Assuntos
Infecções por Mycobacterium não Tuberculosas/imunologia , Mycobacterium marinum/imunologia , Pró-Proteína Convertases/imunologia , Subtilisina/imunologia , Proteínas de Peixe-Zebra/imunologia , Peixe-Zebra/imunologia , Animais , Complexo CD3/biossíntese , Diferenciação Celular/imunologia , Modelos Animais de Doenças , Inativação Gênica , Predisposição Genética para Doença , Granulócitos/citologia , Granulócitos/imunologia , Imunidade Inata/genética , Interleucina-17/metabolismo , Linfotoxina-alfa/metabolismo , Morfolinos/genética , Pró-Proteína Convertases/genética , RNA Mensageiro/biossíntese , Células Th1/imunologia , Tuberculose/imunologia , Fator de Necrose Tumoral alfa/metabolismo , Peixe-Zebra/embriologia , Proteínas de Peixe-Zebra/genética
4.
Hum Genet ; 134(6): 627-36, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25813623

RESUMO

Proprotein convertase subtilisin/kexin (PCSK) enzymes cleave and convert their immature substrates into biologically active forms. Polymorphisms in the PCSK genes have been reported to associate with human diseases and phenotypes, including hypercholesterolemia and blood pressure (BP), and targeting PCSKs is considered a promising future form of drug therapy. PCSK processing is readily induced upon upregulation of the enzyme, but the genetic factors contributing to PCSK expression have not been thoroughly characterized. To gain a comprehensive understanding of the genetic regulation of PCSK expression, we performed, for the first time, a genome-wide expression quantitative trait loci (eQTL) analysis using mRNA expression in >1400 human peripheral blood samples from the Cardiovascular Risk in Young Finns Study and ca. ten million single-nucleotide polymorphisms (SNPs). The expression data showed clear expression for FURIN, PCSK5, PCSK7 and MBTPS1 (membrane-bound transcription factor peptidase, site 1) mRNAs in virtually all tested samples. A discovery analysis demonstrated a genome-wide significant (p < 5 × 10(-8)) association with the selected PCSK probes for 1024 variants, which were located at ten independent loci. Of these loci, 5/10 could be confirmed to regulate PCSK expression in two additional and independent sample sets. Finally, a phenotypic analysis demonstrated that a novel cis-eQTL SNP rs4702 for FURIN is strongly associated with both diastolic (p = 0.012) and systolic (p = 0.035) BP levels, as well as peripheral vascular resistance (p = 0.003). These findings indicate that the expression of the PCSK enzymes is regulated by genetic factors, which have biological roles in health and disease.


Assuntos
Pressão Sanguínea , Furina , Regulação Enzimológica da Expressão Gênica , Estudo de Associação Genômica Ampla , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Feminino , Furina/biossíntese , Furina/genética , Humanos , Masculino , Pró-Proteína Convertases/biossíntese , Pró-Proteína Convertases/genética , Serina Endopeptidases/biossíntese , Serina Endopeptidases/genética , Subtilisinas/biossíntese , Subtilisinas/genética , Resistência Vascular/genética
5.
J Biol Chem ; 288(51): 36610-23, 2013 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-24178295

RESUMO

Proprotein convertase subtilisin/kexin (PCSK) enzymes convert proproteins into bioactive end products. Although other PCSK enzymes are known to be essential for biological processes ranging from cholesterol metabolism to host defense, the in vivo importance of the evolutionarily ancient PCSK7 has remained enigmatic. Here, we quantified the expressions of all pcsk genes during the 1st week of fish development and in several tissues. pcsk7 expression was ubiquitous and evident already during the early development. To compare mammalian and zebrafish PCSK7, we prepared homology models, which demonstrated remarkable structural conservation. When the PCSK7 function in developing larvae was inhibited, we found that PCSK7-deficient fish have defects in various organs, including the brain, eye, and otic vesicle, and these result in mortality within 7 days postfertilization. A genome-wide analysis of PCSK7-dependent gene expression showed that, in addition to developmental processes, several immune system-related pathways are also regulated by PCSK7. Specifically, the PCSK7 contributed to the mRNA expression and proteolytic cleavage of the cytokine TGFß1a. Consequently, tgfß1a morphant fish displayed phenotypical similarities with pcsk7 morphants, underscoring the importance of this cytokine in the zebrafish development. Targeting PCSK activity has emerged as a strategy for treating human diseases. Our results suggest that inhibiting PCSK7 might interfere with normal vertebrate development.


Assuntos
Subtilisinas/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Sequência de Aminoácidos , Animais , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Domínio Catalítico , Sequência Conservada , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Larva/crescimento & desenvolvimento , Larva/metabolismo , Dados de Sequência Molecular , Especificidade de Órgãos , Proteólise , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Homologia de Sequência , Subtilisinas/química , Subtilisinas/genética , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta1/genética , Peixe-Zebra/crescimento & desenvolvimento , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/química , Proteínas de Peixe-Zebra/genética
6.
Biol Blood Marrow Transplant ; 19(8): 1244-53, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23756210

RESUMO

The effect of minor H antigen mismatching on the occurrence of graft-versus-host disease (GvHD) and graft-versus-leukemia (GvL) after HLA-matched hematopoietic stem cell transplantation (HSCT) has mainly been demonstrated in single-center studies. Yet, the International Histocompatibility and Immunogenetics Workshops (IHIW) provide a collaborative platform to execute crucial large studies. In collaboration with 20 laboratories of the IHIW, the roles of 10 autosomal and 10 Y chromosome-encoded minor H antigens were investigated on GvHD and relapse incidence in 639 HLA-identical related donor (IRD) and 210 HLA-matched unrelated donor (MUD) HSCT recipients. Donor and recipient DNA samples were genotyped for the minor H antigens HA-1, HA-2, HA-3, HA-8, HB-1, ACC-1, ACC-2, SP110, PANE1, UGT2B17, and HY. The correlations with the primary outcomes GvHD (acute or chronic GvHD), survival, and relapse were statistically analyzed. The results of these multicenter analyses show that none of the HLA class I-restricted HY antigens were found to be associated with any of the primary outcomes. Interestingly, of the HLA class II-restricted HY antigens analyzed, HLA-DQ5 positive recipients showed a significantly increased GvHD-free survival in female-to-male HSCT compared with male-to-female HSCT (P = .013). Yet, analysis of the overall gender effect, thus independent of the known HY antigens, between the gender groups demonstrated an increased GvHD incidence in the female-to-male transplantations (P < .005) and a decreased GvHD-free survival in the female-to-male transplantations (P < .001). Of all autosomally encoded minor H antigens, only mismatching for the broadly expressed minor H antigen HA-8 increased the GvHD incidence in IRD HSCT (Hazard ratio [HR] = 5.28, P < .005), but not in MUD HSCT. Most striking was the influence of hematopoietic restricted minor H antigens on GvL as mismatching for hematopoietic minor H antigens correlated with lower relapse rates (P = .078), higher relapse-free survival (P = .029), and higher overall survival (P = .032) in recipients with GvHD, but not in those without GvHD. In conclusion, the significant GvHD effect of the broadly expressed minor H antigen HA-8 favors matching for HA-8 in IRD, but not in MUD, patient/donor pairs. The GvHD-GvL association demonstrating a significant lower relapse in hematopoietic minor H antigen mismatched patient/donor pairs underlines their clinical applicability for adoptive immunotherapy, enhancing the GvL effect in a GvHD controllable manner.


Assuntos
Doença Enxerto-Hospedeiro/imunologia , Efeito Enxerto vs Leucemia/imunologia , Transplante de Células-Tronco Hematopoéticas/métodos , Histocompatibilidade/imunologia , Antígenos de Histocompatibilidade Menor/imunologia , Adulto , Feminino , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Teste de Histocompatibilidade , Humanos , Masculino , Doadores não Relacionados
7.
Appl Environ Microbiol ; 79(4): 1221-31, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23220964

RESUMO

The ability to positively affect host health through the modulation of the immune response is a feature of increasing importance in measuring the probiotic potential of a bacterial strain. However, the identities of the bacterial cell components involved in cross talk with immune cells remain elusive. In this study, we characterized the dairy strain Lactobacillus helveticus MIMLh5 and its surface-layer protein (SlpA) using in vitro and ex vivo analyses. We found that MIMLh5 and SlpA exert anti-inflammatory effects by reducing the activation of NF-κB on the intestinal epithelial Caco-2 cell line. On the contrary, MIMLh5 and SlpA act as stimulators of the innate immune system by triggering the expression of proinflammatory factors tumor necrosis factor alpha and COX-2 in the human macrophage cell line U937 via recognition through Toll-like receptor 2. In the same experiments, SlpA protein did not affect the expression of the anti-inflammatory cytokine interleukin-10. A similar response was observed following stimulation of macrophages isolated from mouse bone marrow or the peritoneal cavity. These results suggest that SlpA plays a major role in mediating bacterial immune-stimulating activity, which could help to induce the host's defenses against and responses toward infections. This study supports the concept that the viability of bacterial cells is not always essential to exert immunomodulatory effects, thus permitting the development of safer therapies for the treatment of specific diseases according to a paraprobiotic intervention.


Assuntos
Proteínas de Bactérias/imunologia , Imunidade Inata , Fatores Imunológicos/farmacologia , Lactobacillus helveticus/imunologia , Probióticos/farmacologia , Proteínas de Bactérias/genética , Linhagem Celular , DNA Bacteriano/química , DNA Bacteriano/genética , Células Epiteliais/imunologia , Células Epiteliais/microbiologia , Humanos , Lactobacillus helveticus/genética , Dados de Sequência Molecular , Monócitos/imunologia , Monócitos/microbiologia , Análise de Sequência de DNA
8.
Curr Genomics ; 14(7): 453-67, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24396277

RESUMO

Members of the substilisin/kexin like proprotein convertase (PCSK) protease family cleave and convert immature pro-proteins into their biologically active forms. By cleaving for example prohormones, cytokines and cell membrane proteins, PCSKs participate in maintaining the homeostasis in a healthy human body. Conversely, erratic enzymatic function is thought to contribute to the pathogenesis of a wide variety of diseases, including obesity and hypercholestrolemia. The first characterized seven PCSK enzymes (PCSK1-2, FURIN, PCSK4-7) process their substrates at a motif made up of paired basic amino acid residues. This feature results in a variable degree of biochemical redundancy in vitro, and consequently, shared substrate molecules between the different PCSK enzymes. This redundancy has confounded our understanding of the specific biological functions of PCSKs. The physiological roles of these enzymes have been best illustrated by the phenotypes of genetically engineered mice and patients that carry mutations in the PCSK genes. Recent developments in genome-wide methodology have generated a large amount of novel information on the genetics of the first seven proprotein convertases. In this review we summarize the reported genetic alterations and their associated phenotypes.

9.
J Cell Biochem ; 113(12): 3843-52, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22821512

RESUMO

The Sin3A-associated proteins SAP30 and SAP30L share 70% sequence identity and are part of the multiprotein Sin3A corepressor complex. They participate in gene repression events by linking members of the complex and stabilizing interactions among the protein members as well as between proteins and DNA. While most organisms have both SAP30 and SAP30L, the zebrafish is exceptional because it only has SAP30L. Here we demonstrate that SAP30L is expressed ubiquitously in embryonic and adult zebrafish tissues. Knockdown of SAP30L using morpholino-mediated technology resulted in a morphant phenotype manifesting as cardiac insufficiency and defective hemoglobinization of red blood cells. A microarray analysis of gene expression in SAP30L morphant embryos revealed changes in the expression of genes involved in regulation of transcription, TGF-beta signaling, Wnt-family transcription factors, and nuclear genes encoding mitochondrial proteins. The expression of the heart-specific nkx2.5 gene was markedly down-regulated in SAP30L morphants, and the cardiac phenotype could be partially rescued by nkx2.5 mRNA. In addition, changes were detected in the expression of genes known to be important in hemoglobin synthesis and erythropoiesis. Our results demonstrate that SAP30L regulates several transcriptional pathways in zebrafish embryos and is involved in the development of cardiac and hematopoietic systems.


Assuntos
Embrião não Mamífero/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Coração/embriologia , Hematopoese , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/embriologia , Animais , Embrião não Mamífero/citologia , Eritrócitos/metabolismo , Eritrócitos/patologia , Técnicas de Silenciamento de Genes , Coração/anatomia & histologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Fenótipo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética
10.
Appl Environ Microbiol ; 78(12): 4209-16, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22504812

RESUMO

The use of proper bacterial strains as probiotics for the pharyngeal mucosa is a potential prophylactic strategy for upper respiratory tract infections. In this context, we characterized in vitro the functional and immunomodulatory properties of the strains Lactobacillus helveticus MIMLh5 and Streptococcus salivarius ST3 that were selected during previous investigations as promising pharyngeal probiotics. In this study, we demonstrated in vitro that strains MIMLh5 and ST3, alone and in combination, can efficiently adhere to pharyngeal epithelial cells, antagonize Streptococcus pyogenes, and modulate host innate immunity by inducing potentially protective effects. In particular, we found that the strains MIMLh5 and ST3 activate U937 human macrophages by significantly inducing the expression of the proinflammatory cytokine tumor necrosis factor alpha (TNF-α). Nonetheless, the induction of the anti-inflammatory interleukin-10 (IL-10) by MIMLh5 or ST3 was never lower than that of TNF-α, suggesting that these bacteria can potentially exert a regulatory rather than a proinflammatory effect. We also found that the strains MIMLh5 and ST3 induce cyclooxygenase 2 (COX-2) expression and demonstrated that toll-like receptor 2 (TLR-2) participates in the recognition of the strains MIMLh5 and ST3 by U937 cells. Finally, we observed that these microorganisms grow efficiently when cocultured in milk, suggesting that the preparation of a milk-based fermented product containing both MIMLh5 and ST3 can be a practical solution for the administration of these bacteria. In conclusion, we propose the combined use of L. helveticus MIMLh5 and S. salivarius ST3 for the preparation of novel products that display probiotic properties for the pharyngeal mucosa.


Assuntos
Fatores Imunológicos/farmacologia , Lactobacillus helveticus/fisiologia , Faringe/microbiologia , Probióticos/farmacologia , Streptococcus/fisiologia , Antibiose , Aderência Bacteriana , Células Cultivadas , Ciclo-Oxigenase 2/metabolismo , Células Epiteliais/microbiologia , Humanos , Interleucina-10/metabolismo , Lactobacillus helveticus/imunologia , Macrófagos/imunologia , Macrófagos/microbiologia , Streptococcus/imunologia , Receptor 2 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
11.
BMC Genomics ; 12: 618, 2011 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-22185580

RESUMO

BACKGROUND: Subtilisin/kexin-like proprotein convertase (PCSK) enzymes have important regulatory function in a wide variety of biological processes. PCSKs proteolytically process at a target sequence that contains basic amino acids arginine and lysine, which results in functional maturation of the target protein. In vitro assays have showed significant biochemical redundancy between the seven family members, but the phenotypes of PCSK deficient mice and patients carrying an inactive PCSK allele argue for a specific biological function. Modeling the structures of individual PCSK enzymes has offered little insights into the specificity determinants. However, previous studies have shown that there can be a coordinated expression between a PCSK and its target molecule. Here, we have surveyed the putative PCSK target proteins using genome-wide expression correlation analysis and cleavage site prediction algorithms. RESULTS: We first performed a gene expression correlation analysis over the whole genome for all PCSK enzymes. PCSKs were found to cluster differently based on the strength of correlations. The screen for putative PCSK target proteins showed a significant enrichment (p-values from 1.2e-4 to < 1.0e-10) of putative targets among the most positively correlating genes for most PCSKs. Interestingly, there was no enrichment in putative targets among the genes that correlated positively with the biologically redundant PCSK7, whereas PCSK5 showed an inverse correlation. PCSKs also showed a highly variable degree of shared target genes that were identified by expression correlation and cleavage site prediction. Multiple alignments were used to evaluate the putative targets to pinpoint the important residues for the substrate recognition. Finally, we validated our approach and identified biochemically PAPPA1 and ADAMTS6 as novel targets for FURIN proteolytic activity. CONCLUSIONS: Most PCSK enzymes display strong positive expression correlation with predicted target proteins in our genome-wide analysis. We also show that expression correlation screen combined with a cleavage site-prediction analysis can be used to identify novel bona fide target molecules for PCSKs. Exploring the positively correlating genes can thus offer additional insights into the biology of proprotein convertases.


Assuntos
Estudo de Associação Genômica Ampla , Pró-Proteína Convertases/metabolismo , Animais , Camundongos , Modelos Moleculares , Especificidade por Substrato
12.
Mol Biol Rep ; 38(4): 2603-10, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21107733

RESUMO

Killer cell immunoglobulin-like receptors (KIRs) influence the outcome of haematopoetic stem cell transplantation by modulating the cytotoxic ability of natural killer (NK) cells and a subset of T cells. KIRs are also highly polymorphic and could therefore be good population genetic markers, much like their human leukocyte antigen (HLA) ligands. This study represents the first report on distribution of 16 KIR genes in 162 unrelated healthy Saudi individuals. All the 16 KIR genes were observed in the studied population and the four framework genes (KIR2DL4, 3DL2, 3DL3 and 3DP1) were present in all individuals. Forty- one distinct KIR profiles were expressed in our population, 11 of which had not been previously described in other populations including the Middle Eastern population. AA1, the most common genotypic profile was observed at a frequency of 26.5%. The group A haplotype was more frequent (53%) in the Saudi population compared to the group B haplotype (47%). The pattern of the inhibitory KIR/HLA ligands were also analyzed and 52.3% of the Saudi population was found to express two pairs of the inhibitory KIR/HLA-C. The KIR gene frequencies suggests that the Saudi population shares common general features with the Middle Eastern and other populations, but still has its own unique frequencies of several KIR loci.


Assuntos
Variação Genética , Células Matadoras Naturais/imunologia , Fenótipo , Receptores KIR/genética , Feminino , Genótipo , Antígenos HLA-C/genética , Haplótipos/genética , Humanos , Masculino , Arábia Saudita
13.
Med Teach ; 33(10): 854-6, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21592021

RESUMO

BACKGROUND: Early patient contacts are considered important in medical education. AIMS: We studied the influence of a real patient trigger on study motivation and learning in problem-based study groups of first-year medical and dentistry students. METHODS: 156 eligible students were allocated into 17 groups. Six randomly selected groups received both the real patient and paper trigger, and 11 groups received only the paper trigger. The immediate and later effects of the trigger were assessed with qualitative and quantitative questionnaires and exam scores. The tutors answered questionnaires concerning learning outcomes. RESULTS: The students reported that the real patient trigger significantly improved their study motivation, understanding of the learning objectives and confidence in future patient encounters. The real patient trigger was considered significantly more interesting than the paper case. No statistically significant difference was observed in the exam scores. The tutors observed that groups with poor previous performance gained better results in study sessions. CONCLUSIONS: Real patient triggers motivate students to learn basic medical sciences. Ways to present real patients to students should be considered in medical curricula from early on.


Assuntos
Anatomia/educação , Currículo , Motivação , Assistência ao Paciente/métodos , Aprendizagem Baseada em Problemas/métodos , Estudantes de Medicina/psicologia , Ensino/métodos , Atitude do Pessoal de Saúde , Distribuição de Qui-Quadrado , Educação de Graduação em Medicina/métodos , Humanos , Mentores , Pesquisa Qualitativa , Inquéritos e Questionários
14.
PLoS Genet ; 3(6): e103, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17604453

RESUMO

Minor histocompatibility (H) antigens are allogeneic target molecules having significant roles in alloimmune responses after human leukocyte antigen-matched solid organ and stem cell transplantation (SCT). Minor H antigens are instrumental in the processes of transplant rejection, graft-versus-host disease, and in the curative graft-versus-tumor effect of SCT. The latter characteristic enabled the current application of selected minor H antigens in clinical immunotherapeutic SCT protocols. No information exists on the global phenotypic distribution of the currently identified minor H antigens. Therefore, an estimation of their overall impact in human leukocyte antigen-matched solid organ and SCT in the major ethnic populations is still lacking. For the first time, a worldwide phenotype frequency analysis of ten autosomal minor H antigens was executed by 31 laboratories and comprised 2,685 randomly selected individuals from six major ethnic populations. Significant differences in minor H antigen frequencies were observed between the ethnic populations, some of which appeared to be geographically correlated.


Assuntos
Frequência do Gene , Genética Populacional , Imunofenotipagem , Antígenos de Histocompatibilidade Menor/genética , Grupos Raciais/genética , Feminino , Humanos
15.
BMC Immunol ; 10: 24, 2009 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-19409109

RESUMO

BACKGROUND: Extensive allelic matching in the human leukocyte antigen (HLA) genes is regarded as a prerequisite for good clinical success of allogeneic haematopoietic stem cell transplantation (HSCT). Also other genetic factors can be assumed to play a role in preventing and controlling the complications associated with allogeneic HSCT, in particular graft-versus-host disease (GvHD). Interleukin-10 (IL-10) and its receptor (IL-10R), key regulators of the immune response, are among these candidates. We studied the association of IL-10 and IL-10Rbeta gene polymorphisms with the occurrence of GvHD in 309 HLA-identical sibling donor and recipient pairs. RESULTS: The difference in genotypic IL-10 production between patient and donor in combination with patient IL-10Rbeta A/A genotype predisposed strongly to acute GvHD (OR = 7.15, p = 0.000023). On the other hand, a combination of same genotypic IL-10 production with patient IL-10Rbeta A/A genotype protected from chronic GvHD (OR = 0.407, p = 0.0097). CONCLUSION: Our results suggest that IL-10 and IL-10Rbeta genes have a synergistic effect on the risk of GvHD.


Assuntos
Doença Enxerto-Hospedeiro/genética , Neoplasias Hematológicas/terapia , Subunidade beta de Receptor de Interleucina-10/genética , Interleucina-10/genética , Doença Aguda , Adolescente , Adulto , Idoso , Criança , Doença Crônica , Feminino , Predisposição Genética para Doença , Genótipo , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/imunologia , Antígenos HLA/genética , Antígenos HLA/imunologia , Haplótipos , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Teste de Histocompatibilidade , Humanos , Interleucina-10/imunologia , Subunidade beta de Receptor de Interleucina-10/imunologia , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Irmãos
16.
Haematologica ; 94(4): 528-35, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19278967

RESUMO

BACKGROUND: Matching for HLA genes located on chromosome 6 is required in hematopoietic stem cell transplantation to reduce the incidence of graft-versus-host disease. However, a considerable proportion of patients still suffer from it, obviously due to genetic differences outside the HLA gene region. DESIGN AND METHODS: We studied the similarity of almost 4,000 single nucleotide polymorphisms on chromosome 6 between patients receiving hematopoietic stem cell transplantation and their HLA-matched sibling donors. RESULTS: We observed that as a result of routine HLA matching the siblings in fact shared surprisingly long chromosomal fragments with similar single nucleotide polymorphism genotypes--from 11.65 Mb to 134.66 Mb. The number of genes mapped on these shared fragments varied from 402 to 1,302. Considering the whole chromosome 6, the HLA-matched siblings were apparently identical for 65.2-97.8% of the single nucleotide polymorphisms. CONCLUSIONS: Potentially, genes similar in some transplantation pairs while different in others might have a significant role in determining the outcome after hematopoietic stem cell transplantation.


Assuntos
Cromossomos Humanos Par 6/genética , Transplante de Células-Tronco Hematopoéticas/métodos , Histocompatibilidade/genética , Antígenos HLA/genética , Teste de Histocompatibilidade/métodos , Humanos , Polimorfismo de Nucleotídeo Único , Irmãos , Doadores de Tecidos
17.
J Biomed Inform ; 42(2): 382-9, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19041732

RESUMO

Over half of the DNA of mammalian genomes is transcribed, and one of the emerging enigmas in the field of RNA research is intergenic splicing or transcription induced chimerism. We argue that fused low-copy-number transcripts constitute neglected pathological mechanism akin to copy number variation, due to loss of stoichiometric subunit ratios in protein complexes. An obstacle for transcriptomics meta-analysis of published microarrays is the traditional nomenclature of merged transcript neighbors under same accession codes. Tandem transcripts cover 4-20% of genomes but are only loosely overlapping in population. They were most enriched in systems medicine annotations concerning neurology, thalassemia and genital disorders in the GeneGo Inc. MetaCore-MetaDrug(TM) knowledgebase, evaluated with external randomizations here. Clinical transcriptomics is good news since new disease etiologies offer new remedies. We identified homeotic HOX-transfactors centered around BMI-1, the Grb2 adaptor network, the kallikrein system, and thalassemia RNA surveillance as vulnerable hotspot chimeras. As a cure, RNA interference would require verification of chimerism from symptomatic tissue contra healthy control tissue from the same patient.


Assuntos
Bases de Dados de Ácidos Nucleicos , Perfilação da Expressão Gênica/métodos , Genômica/métodos , Proteínas Mutantes Quiméricas/genética , Algoritmos , Dosagem de Genes , Redes Reguladoras de Genes , Humanos , Interferência de RNA , Splicing de RNA
18.
Transplantation ; 83(7): 948-53, 2007 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-17460567

RESUMO

BACKGROUND: Cold storage of tissues induces reactive oxygen species (ROS), which contribute to cell injury. We have compared different antioxidants in protection of renal tubular cells against hypothermia injury and studied their effect on cold-induced mitogen-activated protein (MAP) kinase activation. METHODS: Cultured renal tubular epithelial cells (LLC-PK1) were stored in University of Wisconsin solution supplemented with compounds tested for 16 hr at 4 degrees C. Release of lactate dehydrogenase and cellular adenosine triphosphate were measured. Activation of MAP kinases was determined by Western blotting. Intracellular ROS were monitored with a fluorescent probe. RESULTS: Cold storage resulted in a substantial loss of cell viability. The simple phenol butylated hydroxyanisol (BHA) most effectively prevented hypothermia-induced cell injury, whereas about 100-fold higher concentration of the polyphenol epigallocatechin gallate (EGCG) was needed, although EGCG most effectively scavenged intracellular ROS elicited by serum withdrawal. The MEK inhibitor U0126 and reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor diphenyleneiodonium effectively protected the cells against hypothermia injury. ERK1/2 was rapidly activated during chilling of the cells and this was inhibited by BHA but not by EGCG. CONCLUSION: The results suggest that chilling of renal epithelial cells induces ROS generation by NADPH oxidase, which leads to rapid activation of the MEK-ERK1/2 cascade and initiation of cell injury. This can be prevented by antioxidants.


Assuntos
Antioxidantes/farmacologia , Túbulos Renais/citologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fenóis/farmacologia , Animais , Linhagem Celular , Temperatura Baixa , Ativação Enzimática , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/fisiologia , Túbulos Renais/efeitos dos fármacos , Túbulos Renais/enzimologia , L-Lactato Desidrogenase/análise , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 3 Ativada por Mitógeno/antagonistas & inibidores , Preservação de Órgãos , Espécies Reativas de Oxigênio , Suínos
19.
Eur J Endocrinol ; 149(6): 591-6, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14641002

RESUMO

OBJECTIVE: The effect of polymorphisms of the vitamin D receptor (VDR) gene on susceptibility to type 1 diabetes has recently been investigated extensively. Several findings on positive disease associations have been observed and, in addition, a protective effect of vitamin D supplementation has been reported. DESIGN: We studied the effect of three vitamin D receptor gene polymorphisms (VDRA, VDRB, VDRF) on susceptibility to type 1 diabetes in a large case-control series (more than 2000 controls and about 1000 patients) from the Finnish population. METHODS: A combination of case-control and affected-family based approaches was used. Subjects were genotyped for VDRA (ApaI), VDRB (BsmI) and VDRF (FokI) single nucleotide polymorphisms using a minisequencing reaction. RESULTS: A few borderline significant associations were observed with both approaches used. In the case-control association analyses we found significant differences between cases and controls in frequencies of VDRB (P=0.024, all subjects and P=0.016, HLA DQB1*0302-positive subjects) and VDRF (P=0.0063, Turku cohort). In the total family set a decreased (39.3%) transmission of the VDRA-VDRB-VDRF haplotype 1-1-2 and an increased (60.3%) transmission of haplotype 2-1-2 to sons was seen (P=0.0059 and P=0.024 respectively). Transmission of the haplotype 2-2-1 to daughters was decreased (37.6%, P=0.022). Interestingly, we also observed significant differences in allele frequencies of the polymorphisms studied between populations from three different regions in Finland. CONCLUSIONS: All these differences disappeared after correction for multiple testing. We conclude that the single nucleotide polymorphisms analysed are unlikely to be associated with type 1 diabetes in the Finnish population.


Assuntos
Diabetes Mellitus Tipo 1/genética , Predisposição Genética para Doença , Polimorfismo Genético , Receptores de Calcitriol/genética , Adolescente , Adulto , Estudos de Casos e Controles , Cromossomos Humanos Par 12/genética , Diabetes Mellitus Tipo 1/epidemiologia , Feminino , Finlândia/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem
20.
Clin Biochem ; 36(8): 633-40, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14636879

RESUMO

OBJECTIVES: A reliable high-throughput assay system is necessary for the analysis of the ever-increasing numbers of single-nucleotide polymorphisms (SNP) relevant to genetic screening studies. We describe an assay suitable also for large-scale screening programs. DESIGN AND METHODS: The one-step assay is based on asymmetric PCR amplification of the target sequence and subsequent time-resolved fluorescence measurement. Asymmetric amplification results in a single-stranded PCR product that is detected in the amplification vessel with a highly sensitive, homogeneous hybridization method. RESULTS: A dual label, homogeneous high-throughput platform for nucleic acid sequence analysis was developed and validated using a C/T single-nucleotide polymorphism in the insulin gene as a model analyte and applied also to two other SNP-assays (poliovirus receptor A/G-polymorphism and CD86-gene exon 2 A/G-polymorphism). CONCLUSIONS: The described high-throughput genotyping technology is very competitive in price, simple in design and easily applied to any analyte sequence.


Assuntos
Hibridização de Ácido Nucleico/métodos , Polimorfismo de Nucleotídeo Único/genética , Testes Genéticos/métodos , Genótipo , Humanos , Insulina/genética , Reação em Cadeia da Polimerase/métodos
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