RESUMO
The present study aimed to perform a mini-review of the complete soluble isoforms of Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin (sDC-SIGN), their functions, and their correlation with diseases. The present review reveals the lack of studies regarding these soluble isoforms and poor understanding of the importance of the topic, considering the concordant findings on the relevant influence of sDC-SIGN in the viral and bacterial infection process, in addition to its possible use as a cancer marker.
Assuntos
Células Dendríticas , Lectinas Tipo C , Moléculas de Adesão Celular , Lectinas Tipo C/genética , Ligantes , Isoformas de Proteínas/genética , Receptores de Superfície CelularRESUMO
The DC-SIGN glycoprotein is responsible for the initial adhesion of dengue virus (DENV) to immune cells by the carbohydrate recognition domain (CRD). There are thirteen soluble and membrane-bound DC-SIGN isoforms, but the role of soluble isoforms in the DENV internalization process is not known. Five isoforms with an altered or absent CRD were identified, and three different soluble isoforms were used to confirm the interactions with mannose residues. The results show the loss of binding ability of one soluble isoform and binding ability of two of them. All of them will be used to verify their role in the DENV internalization process.
Assuntos
Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Vírus da Dengue/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Manose/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Ligação Viral , Internalização do Vírus , Sequência de Aminoácidos , Sequência de Bases , Dengue/virologia , Vírus da Dengue/genética , Ligantes , Ligação Proteica/genética , Isoformas de Proteínas/genéticaRESUMO
Dengue is the most prevalent arthropod-borne viral illness in humans worldwide. Single-nucleotide polymorphisms (SNPs) in genes involved in the immune response, such as dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN), IgG Fc receptor II-A (FcγRIIa), vitamin D receptor (VDR), and tumor necrosis factor alpha (TNF-α), were previously reported to be associated with susceptibility to dengue disease in different human populations. Therefore, due to the relevant association of host immune and genetic status with disease susceptibility/severity of dengue, this work aims to verify the frequency of anti-dengue virus antibodies and some dengue-associated risk SNPs in a population in Minas Gerais State, Southeast Brazil. A total of 1560 individuals were genotyped for polymorphisms in DC-SIGN (rs4804803), FcγRIIa (rs1801274), VDR (rs7975232), and TNF-α (rs1800629). The presence of anti-dengue antibodies (IgM and/or IgG) in these samples was also assayed. Anti-dengue antibodies were detected at an overall frequency of 16.86%, indicating a virus infection in asymptomatic individuals. The genotypic frequencies of all SNPs studied did not differ between the asymptomatic and control groups. Regarding the allelic frequencies of the four SNPs analyzed, a higher frequency was detected of the G allele of FcγRIIa/rs1801274 in the asymptomatic individuals when compared to that in the control group (p = 0.03). Therefore, the results showed a high prevalence of asymptomatic individuals in Minas Gerais State, with a potential association between the presence of the G allele of FcγRIIa/rs1801274 and protection against symptomatic disease.
Assuntos
Dengue/genética , Dengue/imunologia , Receptores de IgG/genética , Adulto , Arginina/genética , Brasil , Moléculas de Adesão Celular/genética , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Lectinas Tipo C/genética , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Prevalência , Receptores de Calcitriol/genética , Receptores de Superfície Celular/genética , Fator de Necrose Tumoral alfa/genéticaRESUMO
Dengue virus (DENV) infection can lead to a wide range of clinical manifestations, including fatal hemorrhagic complications. There is a need to find effective pharmacotherapies to treat this disease due to the lack of specific immunotherapies and antiviral drugs. That said, the DENV NS2B/NS3pro protease complex is essential in both the viral multiplication cycle and in disease pathogenesis, and is considered a promising target for new antiviral therapies. Here, we performed a systematic review to evaluate the pharmacophoric characteristics of promising compounds against NS2B/NS3pro reported in the past 10 years. Online searches in the PUBMED/MEDLINE and SCOPUS databases resulted in 165 articles. Eight studies, which evaluated 3,384,268 molecules exhibiting protease inhibition activity, were included in this review. These studies evaluated anti-dengue activity in vitro and the IC50 and EC50 values were provided. Most compounds exhibited non-competitive inhibition. Cytotoxicity was evaluated in BHK-21, Vero, and LLC-MK2 cells, and the CC50 values obtained ranged from < 1.0 to 780.5 µM. Several groups were associated with biological activity against dengue, including nitro, catechol, halogen and ammonium quaternaries. Thus, these groups seem to be potential pharmacophores that can be further investigated to treat dengue infections.
Assuntos
Antivirais/farmacologia , Vírus da Dengue/efeitos dos fármacos , Inibidores de Proteases/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Animais , Antivirais/química , Sítios de Ligação , Linhagem Celular , Vírus da Dengue/enzimologia , Vírus da Dengue/crescimento & desenvolvimento , Humanos , Simulação de Acoplamento Molecular , Inibidores de Proteases/química , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , RNA Helicases/antagonistas & inibidores , RNA Helicases/química , RNA Helicases/metabolismo , Serina Endopeptidases/química , Serina Endopeptidases/metabolismo , Relação Estrutura-Atividade , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/efeitos dos fármacosRESUMO
Dengue, caused by any of the four types of Dengue virus (DENV) is the most important arbovirus in the world. In this study we performed a molecular surveillance of dengue during the greatest dengue outbreak that took place in Divinópolis, Minas Gerais state, Southeast Brazil, in 2013. Samples from 100 patients with clinical symptoms of dengue were studied and 26 were positive. The capsid/premembrane (CprM) and envelope gene sequences of some samples were amplified and sequenced. Molecular analyses demonstrated that two DENV-1 lineages, belonging to genotype V were introduced and co-circulated in Divinópolis. When compared to each other, those lineages presented high genetic diversity and showed unique amino acids substitutions in the envelope protein, including in domains I, II, and III. DENV-4 strains from Divinópolis clustered within genotype IIb and the most recent common ancestor was probably introduced into the city three years before the 2013 epidemic. Here we demonstrated for the first time the circulation of DENV-4 and the co-circulation of two DENV-1 lineages in Midwest region of Minas Gerais, Brazil. Moreover our analysis indicated the introduction of five DENV-1 lineages, genotype V into Brazil, in different times. J. Med. Virol. 89:966-973, 2017. © 2016 Wiley Periodicals, Inc.
Assuntos
Vírus da Dengue/classificação , Vírus da Dengue/genética , Dengue/epidemiologia , Dengue/virologia , Variação Genética , Genótipo , Substituição de Aminoácidos , Brasil/epidemiologia , Análise por Conglomerados , Vírus da Dengue/isolamento & purificação , Monitoramento Epidemiológico , Humanos , Epidemiologia Molecular , Mutação , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Proteínas Estruturais Virais/genéticaRESUMO
Dengue is the most prevalent arthropod-borne viral illness in humans. The overexpression of cytokines by Dengue virus (DENV) infected cells is associated with the most severe forms of the disease. Unmethylated CpG islands are related to a transcriptionally active structure, whereas methylated DNA recruits methyl-binding proteins that inhibit gene expression. Several studies have described the importance of epigenetic events in the regulation and expression of many cytokines. The purpose of the present study was to evaluate the methylation status of the IFN-γ and TNF-α promoters in DNA extracted from dengue infected patients using methylation-specific polymerase chain reaction. A high frequency of demethylation was observed in the TNF-α promoter of DENV infected patients when compared to non-infected controls. The patients with an unmethylated profile showed higher expression of TNF-α mRNA than patients with the methylated status. No difference was found in the methylation frequency between the two analyzed groups regarding the IFN-γ promoter or in the expression of IFN-γ transcripts. The present study provides the first association of TNF-α promoter demethylation in DENV infected individuals and demonstrates a correlation between the methylation status of the region analyzed and the expression of TNF-α transcripts in DENV infected patients. J. Med. Virol. 88:1297-1302, 2016. © 2016 Wiley Periodicals, Inc.
Assuntos
Metilação de DNA , Vírus da Dengue/imunologia , Dengue/genética , Dengue/imunologia , Regiões Promotoras Genéticas , Fator de Necrose Tumoral alfa/genética , Adulto , Ilhas de CpG , Feminino , Humanos , Interferon gama/genética , Interferon gama/imunologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , RNA Viral/sangue , RNA Viral/isolamento & purificação , Fator de Necrose Tumoral alfa/imunologia , Adulto JovemRESUMO
OBJECTIVE: To entomologically monitor Aedes spp. and correlate the presence of these vectors with the recent epidemic of dengue in Divinopolis, Minas Gerais State, Brazil. METHODS: Ovitraps were installed at 44 points in the city, covering six urban areas, from May 2011 to May 2012. After collection, the eggs were incubated until hatching. In the 4th stage of development, the larvae were classified as Ae. aegypti or Ae. albopictus. RESULTS: In total, 25 633 Aedes spp. eggs were collected. February was the month with the highest incidence, with 5635 eggs collected and a hatching rate of 46.7%. Ae. aegypti eggs had the highest hatching rate, at 72.3%, whereas Ae. albopictus eggs had 27.7%. Climate and population density influenced the number of eggs found. Indicators of vector presence were positively correlated with the occurrence of dengue cases. CONCLUSION: These data reinforce the need for entomological studies, highlight the relevance of Ae. albopictus as a possible disease vector and demonstrate its adaptation. Ae. albopictus, most commonly found in forested areas, comprised a substantial proportion of the urban mosquito population.
Assuntos
Aedes/crescimento & desenvolvimento , Dengue/transmissão , Insetos Vetores/crescimento & desenvolvimento , Animais , Brasil/epidemiologia , Dengue/epidemiologia , Surtos de Doenças , Entomologia , Humanos , Larva/crescimento & desenvolvimento , Estações do Ano , Temperatura , Saúde da População UrbanaRESUMO
BACKGROUND: A detailed understanding of the genetic basis of cancer is of great interest to public health monitoring programs. Although many studies have been conducted in Brazil, a global view on the molecular profile related to hereditary breast and ovarian cancer (HBOC) in this large and heterogeneous population is lacking. METHODS: A systematic review following the PRISMA guidelines was conducted in three electronic databases (PubMed, BIREME and SciELO). Brazilian studies covering molecular analysis of genes related to HBOC, published until December 2023, were considered. RESULTS: We identified 35 original studies that met all the inclusion criteria. A total of 137 distinct mutations were found in the BRCA1 gene, but four of them corresponded to 44.5% of all mutations found in this gene. The c.5266dupC BRCA1 mutation was responsible for 26.8% of all pathogenic mutations found in the BRCA1 gene in patients with clinical criteria for HBOC from the Brazilian population. Considering all studies that track this mutation in the BRCA1 gene, we found a frequency of 2% (120/6008) for this mutation in Brazilian patients. In the BRCA2 gene, the four most frequent mutations corresponded to 29.2% of pathogenic mutations. Even though it was tracked by few studies, the c.156_157insAlu mutation was responsible for 9.6% of all pathogenic mutations reported in the BRCA2 gene. Seventeen studies found pathogenic mutations in other non-BRCA genes, the c.1010G > A mutation in the TP53 gene being the most frequent one. Considering all studies that screened for this specific mutation in patients with the clinical criteria for HBOC, the frequency of c.1010G > A was estimated at 1.83% (61/3336). CONCLUSIONS: Despite significant molecular heterogeneity among mutations in HBOC patients from Brazil, three mutations deserve to be highlighted, c.5266dupC, c.156_157insAlu and c.1010G > A in the BRCA1, BRCA2 and TP53 genes, respectively. With more than 200 records, these three mutations play a vital role in the pathology of breast and ovarian cancer in Brazil. The data collected shed light on the subject, but there is still not enough data from certain subpopulations.
Assuntos
Neoplasias da Mama , Síndrome Hereditária de Câncer de Mama e Ovário , Neoplasias Ovarianas , Feminino , Humanos , Brasil/epidemiologia , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Síndrome Hereditária de Câncer de Mama e Ovário/epidemiologia , Síndrome Hereditária de Câncer de Mama e Ovário/genética , Mutação/genética , Neoplasias Ovarianas/epidemiologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologiaRESUMO
Cervical uterine cancer is the second most frequent form of cancer in the female population and the fourth cause of cancer deaths among Brazilian women. In Divinópolis county, Minas Gerais state, cervical cancer accounted for 6.6% of deaths in 2007. The purpose of this study was to conduct an epidemiological and molecular investigation of samples of pre-neoplastic and neoplastic cervical uterine lesions from patients assisted at public healthcare services in the county. The study was based on clinical-epidemiological descriptions retrieved from cytological examination request forms from 2006 to 2010. For molecular analysis, samples from 95 patients were collected and DNA was extracted using the Chelex 100 method. PCR was performed for detection and typing of HPV 6/11, 16, 18, 31, and 33. Of the 52 168 patients who underwent cytological examination, 625 had pre-neoplastic or neoplastic lesions during the study period. Age distribution was consistent with the literature, with a predominance of patients aged 20-49 years. The microorganism found most frequently was Lactobacillus sp. (65%). Prominent among cellular alterations were cervical intraepithelial neoplasia I (39.7%) and atypical squamous cells of undetermined significance (32%). Molecular analysis revealed 72.6% of positive samples for HPV. HPV 16 (26.3%) was the most frequent type, followed by types 6/11 (7.4%), 18 (5.3%), 33 (2.1%), and 31 (1%). The results provided improved understanding of the association between HPV and cancer in Divinópolis, in addition to providing data that can contribute to the design of measures to prevent and control HPV infection in the county investigated.
Assuntos
Papillomaviridae/classificação , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/patologia , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/patologia , Adulto , Brasil/epidemiologia , DNA Viral/genética , DNA Viral/isolamento & purificação , Feminino , Humanos , Pessoa de Meia-Idade , Papillomaviridae/genética , Infecções por Papillomavirus/virologia , Reação em Cadeia da Polimerase , Neoplasias do Colo do Útero/virologia , Adulto JovemRESUMO
BACKGROUND: Allele frequencies for six STR/miniSTR loci were determined in a sample of unrelated individuals from Southeastern Brazil. METHODS AND RESULTS: No significant deviations from Hardy-Weinberg equilibrium proportions were observed for the loci investigated (p-values ≥ 0.2320). Statistical parameters of forensic interest such as heterozygosity (H), power of discrimination (PD) and power of exclusion (PE) were estimated. Except for marker FABP2, all STR/miniSTRs tested showed observed heterozygosities over 0.66.Combined power of discrimination and power of exclusion were 0.9999993 and 0.9925, respectively. CONCLUSIONS: Due to their ease of analysis and high informativity, these new STR multiplexes will be useful for extending current marker sets for forensic and paternity purposes.
Assuntos
Antígenos CD4/genética , Proteínas de Ligação a Ácido Graxo/genética , Genética Forense , Frequência do Gene , Repetições de Microssatélites , Alelos , Sequência de Bases , Brasil , Impressões Digitais de DNA , Marcadores Genéticos , Humanos , Paternidade , Reação em Cadeia da PolimeraseRESUMO
INTRODUCTION: Deafness is the most frequent sensory deficit in humans. Incidence is estimated at 4:1000 births in Brazil. Specific programs for clinical care of patients with hearing loss are still scarce in Brazil and the issue is an important public health problem. OBJECTIVE: To determine the frequency of 35delG and D13S1830 mutations in GJB2 and GJB6 genes respectively in patients with non-syndromic sensorineural hearing loss from Minas Gerais, Brazil. METHODS: This research involved 53 individuals, who were assessed by a questionnaire for predicting the possibility of non-syndromic deafness and for data collecting. Samples were tested for the presence of the 35delG mutation in GJB2 gene and D13S1830 in GJB6 gene by polymerase chain reaction and restriction enzyme digestion. RESULTS: Epidemiological research has shown that the majority of the subjects are unaware of the etiology and the pathogenesis of hearing loss. In 9 patients (16.98%), 35delG mutation was found in heterozygosis and the allele frequency was estimate to be around 8.5%. Although 9.61% of the patients reported having some degree of consanguinity between the parents and 12.08% reported other cases of deafness in their families, this mutation was not found in homozygosis. The D13S1830 mutation was not found in this study. CONCLUSION: This research describes for the first time the frequency of the 35delG and D13S1830 mutation in hearing-impaired individuals from Minas Gerais, Brazil, and the collected data reinforce the need for further studies in this population due to heterogeneity of hearing loss.
Assuntos
Perda Auditiva Neurossensorial/genética , Mutação/genética , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Genótipo , Humanos , Masculino , Reação em Cadeia da Polimerase , Adulto JovemRESUMO
BACKGROUND: Few studies related to hereditary breast and ovarian cancer syndrome (HBOC) have been conducted in Brazil, and they are restricted to only small areas of the country. Here, we report the mutation profile of BRCA1/2, CHEK2 and TP53 genes in a cohort from Minas Gerais state. METHODS: These genes from 44 patients at high risk for HBOC were screened through high-resolution melting and/or sequencing. The pathogenicity of the alterations was checked using ClinVar database and bioinformatics programs. RESULTS: In BRCA genes we identified 46 variants, 38 without clinical significance and 8 pathogenic mutations including a new pathogenic mutation in BRCA1 gene (c.4688_4694delACCTGGAinsG). The most prevalent pathogenic mutation was c.4829_4830delTG, in the BRCA2 gene. This mutation was not described in the Brazilian population up to now and in this study, it was described with a prevalence of 6.8%. The p.R337H mutation in TP53 gene was found in one patient clinically diagnosed as HBOC and without clinical criteria for Li-Fraumeni syndrome. In CHEK2 gene, the undescribed variant c.485A > G was found and it presents as probably pathogenic through in silico analyses. Pathogenic mutations were found in 29.5% of the patients, 11.3% in BRCA1, 15.9% in BRCA2 and 2.3% in TP53 gene. CONCLUSIONS: Brazilian population is one of the most heterogeneous in the world and the mutational profile knowledge of genes related to HBOC from different regions can contribute to the definition of more cost-effective strategies for the prevention, identification and treatment of cancer.
Assuntos
Predisposição Genética para Doença/genética , Síndrome Hereditária de Câncer de Mama e Ovário/genética , Adulto , Idoso , Proteína BRCA1/genética , Proteína BRCA2/genética , Brasil , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Quinase do Ponto de Checagem 2/genética , Estudos de Coortes , Feminino , Síndrome Hereditária de Câncer de Mama e Ovário/patologia , Humanos , Pessoa de Meia-Idade , Mutação , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Proteína Supressora de Tumor p53/genéticaRESUMO
OBJECTIVE: to estimate the prevalence of TaqIA, -141C and rs6280 polymorphisms of the ANKK1, DRD2 and DRD3 genes and evaluate their association with the occurrence of metabolic syndrome in patients with refractory schizophrenia. METHOD: cross-sectional study conducted in the Extended Western Region of Minas Gerais, with refractory schizophrenic patients using the antipsychotic clozapine. Sociodemographic, clinical, anthropometric, biochemical and genetic data were collected. Univariate analysis of the data was performed. RESULTS: seventy-two patients participated in the study and the occurrence of Metabolic Syndrome was observed in 47.2% of them. There was no association between Metabolic Syndrome and the studied polymorphisms. There was a statistically significant difference in the low HDL parameter with homozygous genotype for the C allele of the -141C polymorphism of the DRD2 gene. CONCLUSION: a high prevalence of MS was evidenced. The -141C polymorphism was associated with low HDL. Genetic analysis and identification of metabolic alterations in this group of patients can guide drug treatment and provide a better quality of life.
Assuntos
Síndrome Metabólica/complicações , Síndrome Metabólica/genética , Polimorfismo Genético , Proteínas Serina-Treonina Quinases/genética , Receptores de Dopamina D2/genética , Receptores de Dopamina D3/genética , Esquizofrenia/complicações , Esquizofrenia/genética , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Síndrome Metabólica/epidemiologia , PrevalênciaRESUMO
Human schistosomiasis is a neglected tropical disease of great importance in public health. A large number of people are infected with schistosomiasis, making vaccine development and effective diagnosis important control strategies. A rational epitope prediction workflow using Schistosoma mansoni hypothetical proteins was previously presented by our group, and an improvement to that approach is presented here. Briefly, immunodominant epitopes from parasite membrane proteins were predicted by reverse vaccinology strategy with additional in silico analysis. Furthermore, epitope recognition was evaluated using sera of individuals infected with S. mansoni. The epitope that stood out in both in silico and in vitro assays was used to compose a rational chimeric molecule to improve immune response activation. Out of 2185 transmembrane proteins, four epitopes with high binding affinities for human and mouse MHCII molecules were selected through computational screening. These epitopes were synthesized to evaluate their ability to induce TCD4+ lymphocyte proliferation in mice. Sm204830e and Sm043300e induced significant TCD4+ proliferation. Both epitopes were submitted to enzyme-linked immunosorbent assay to evaluate their recognition by IgG antibodies from the sera of infected individuals, and epitope Sm043300 was significantly recognized in most sera samples. Epitope Sm043300 also showed good affinity for human MHCII molecules in molecular docking, and its sequence is curiously highly conserved in four S. mansoni proteins, all of which are described as G-protein-coupled receptors. In addition, we have demonstrated the feasibility of incorporating this epitope, which showed low similarity to human sequences, into a chimeric molecule. The stability of the molecule was evaluated by molecular modeling aimed at future molecule production for use in diagnosis and vaccination trials.
Assuntos
Antígenos de Helmintos/imunologia , Epitopos Imunodominantes/imunologia , Schistosoma mansoni/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Anti-Helmínticos/sangue , Anticorpos Anti-Helmínticos/imunologia , Antígenos de Helmintos/genética , Linfócitos T CD4-Positivos/imunologia , Técnicas de Química Combinatória , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Feminino , Cadeias HLA-DRB1/imunologia , Proteínas de Helminto/química , Proteínas de Helminto/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Epitopos Imunodominantes/genética , Epitopos Imunodominantes/metabolismo , Ativação Linfocitária , Proteínas de Membrana/química , Proteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Modelos Moleculares , Simulação de Acoplamento Molecular , Conformação Proteica , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/imunologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Schistosoma haematobium/imunologia , Schistosoma mansoni/genética , Esquistossomose mansoni/sangue , Esquistossomose mansoni/imunologia , Alinhamento de Sequência , Vacinas de Subunidades Antigênicas/imunologia , Vacinas Sintéticas/imunologiaRESUMO
Phenylketonuria (PKU) is one of the few genetic diseases in which mental retardation can be prevented. Hence, diagnosis and treatment must be established early. PKU treatment consists of a phenylalanine-restricted diet supplemented with a phenylalanine-free mixture of amino acids. However, it is difficult to adhere to this diet. In the last decade, a better comprehension of the biochemistry, genetics and molecular basis of the disease, as well as the need for easier treatment, led to the development of several new therapeutic strategies for PKU. In the present study, we evaluated these new therapeutic options in terms of theoretical basis, methodologies, efficacy, and costs.
Assuntos
Dieta com Restrição de Proteínas/métodos , Alimentos Formulados , Fenilalanina Hidroxilase , Fenilcetonúrias/dietoterapia , Aminoácidos/administração & dosagem , Alimentos/normas , Terapia Genética/métodos , Humanos , Fenótipo , Fenilalanina/administração & dosagem , Fenilcetonúrias/genética , PaladarRESUMO
In order to determine the phenylketonuria (PKU) mutation spectrum in the population of Minas Gerais State, Brazil, 78 unrelated PKU patients found by the neonatal screening program from 1993 to 2003 were tested for nine phenylalanine hydroxylase mutations. These mutations were selected due to their high frequencies in other Brazilian populations and in Portugal, where the largest contingent of the Caucasian component of the Brazilian population originated from. The most frequent mutations were V388M (21%), R261Q (16%), IVS10nt11 (13.4%), I65T (5.7%), and R252W (5%). The frequencies of the other four mutations (R261X, R408W, Y414C, and IVS12nt1) did not reach 2%. By testing these nine mutations, we were able to identify 64% of the PKU alleles in our sample. V388M frequency was higher than in any other known population and almost three times larger than that observed in Portugal, probably reflecting genetic drift. The mutation profile, as well as the relative frequency of the different mutations, suggest that the Minas Gerais population more closely resembles that of Portugal than do the other Brazilian populations that have already been tested.
Assuntos
Mutação/genética , Fenilalanina Hidroxilase/genética , Fenilcetonúrias/genética , Brasil/epidemiologia , Eletroforese em Gel de Poliacrilamida , Testes Genéticos , Humanos , Recém-Nascido , Triagem Neonatal , Fenilcetonúrias/epidemiologiaRESUMO
The aim of this study was to evaluate the profile of BRCA1 mutations among cancer-affected Brazilian women from the Midwest region of Minas Gerais state with clearly defined risk factors for hereditary breast and ovarian cancer (HBOC) syndrome. In this Brazilian region, the first Center for Hereditary Cancer Control began operation in 2011, and 90% of patients receive assistance from the public health service. Eighteen patients at high risk for HBOC were subjected to molecular analysis. Primers were designed for 22 coding exons of the gene; DNA was extracted; and real-time PCR followed by high-resolution melting reaction was performed. The amplicons were sequenced to confirm the identified profiles. Only exon 11 was directly sequenced due its length. Multiplex ligation-dependent probe amplification (MLPA) was performed for those patients in whom no pathogenic mutations were found. Among the 14 alterations identified in this study, the c.5263_5264insC pathogenic mutation was present in two patients (11.1%). Four alterations showed no clinical relevance; one exhibited inconclusive clinical relevance according to the examined databases; and eight alterations presented a divergent classification between the databases. No deletions or duplications were found using the MLPA technique. The HRM methodology was highly sensitive in identifying variants in the BRCA1 gene and can dramatically reduce the amount of sequencing required to identify germline mutations in BRCA genes, enabling cheaper tests and increasing their availability to Brazilian women assisted by the public health service.
Assuntos
Proteína BRCA1/genética , Neoplasias da Mama/genética , Testes Genéticos/métodos , Neoplasias Ovarianas/genética , Adulto , Idoso , Brasil , Feminino , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase MultiplexRESUMO
Corynebacterium pseudotuberculosis is the etiological agent of caseous lymphadenitis, a disease that predominantly affects small ruminants, causing significant economic losses worldwide. As a facultative intracellular pathogen, this bacterium is exposed to an environment rich in reactive oxygen species (ROS) within macrophages. To ensure its genetic stability, C. pseudotuberculosis relies on efficient DNA repair pathways for excision of oxidative damage such as 8-oxoguanine, a highly mutagenic lesion. MutY is an adenine glycosylase involved in adenine excision from 8-oxoG:A mismatches avoiding genome mutation incorporation. The purpose of this study was to characterize MutY protein from C. pseudotuberculosis and determine its involvement with DNA repair. In vivo functional complementation assay employing mutY gene deficient Escherichia coli transformed with CpmutY showed a 13.5-fold reduction in the rate of spontaneous mutation, compared to cells transformed with empty vector. Also, under oxidative stress conditions, CpMutY protein favored the growth of mutY deficient E. coli, relative to the same strain in the absence of CpMutY. To demonstrate the involvement of this enzyme in recognition and excision of 8-oxoguanine lesion, an in vitro assay was performed. CpMutY protein was capable of recognizing and excising 8-oxoG:A but not 8-oxoG:C presenting evidences of glycosylase/AP lyase activity in vitro. In silico structural characterization revealed the presence of preserved motifs related to the MutY activity on DNA repair, such as catalytic residues involved in glycosylase/AP lyase activity and structural DNA-binding elements, such as the HhH motif and the [4Fe-4S] cluster. The three-dimensional structure of CpMutY, generated by comparative modeling, exhibits a catalytic domain very similar to that of E. coli MutY. Taken together, these results indicate that the CpmutY encodes a functional protein homologous to MutY from E. coli and is involved in the prevention of mutations and the repair of oxidative DNA lesions.
Assuntos
Corynebacterium pseudotuberculosis/genética , Corynebacterium pseudotuberculosis/metabolismo , DNA Glicosilases/metabolismo , DNA Liase (Sítios Apurínicos ou Apirimidínicos)/metabolismo , Mutação , Fenótipo , Sequência de Aminoácidos , DNA Glicosilases/química , DNA Glicosilases/deficiência , DNA Glicosilases/genética , Reparo do DNA , Ativação Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Guanina/análogos & derivados , Guanina/metabolismo , Modelos Moleculares , N-Glicosil Hidrolases/metabolismo , Conformação de Ácido Nucleico , Estresse Oxidativo , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteínas RecombinantesRESUMO
Abstract Introduction: Deafness is the most frequent sensory deficit in humans. Incidence is estimated at 4:1000 births in Brazil. Specific programs for clinical care of patients with hearing loss are still scarce in Brazil and the issue is an important public health problem. Objective: To determine the frequency of 35delG and D13S1830 mutations in GJB2 and GJB6 genes respectively in patients with non-syndromic sensorineural hearing loss from Minas Gerais, Brazil. Methods: This research involved 53 individuals, who were assessed by a questionnaire for predicting the possibility of non-syndromic deafness and for data collecting. Samples were tested for the presence of the 35delG mutation in GJB2 gene and D13S1830 in GJB6 gene by polymerase chain reaction and restriction enzyme digestion. Results: Epidemiological research has shown that the majority of the subjects are unaware of the etiology and the pathogenesis of hearing loss. In 9 patients (16.98%), 35delG mutation was found in heterozygosis and the allele frequency was estimate to be around 8.5%. Although 9.61% of the patients reported having some degree of consanguinity between the parents and 12.08% reported other cases of deafness in their families, this mutation was not found in homozygosis. The D13S1830 mutation was not found in this study. Conclusion: This research describes for the first time the frequency of the 35delG and D13S1830 mutation in hearing-impaired individuals from Minas Gerais, Brazil, and the collected data reinforce the need for further studies in this population due to heterogeneity of hearing loss.
Resumo Introdução: A surdez é o déficit sensorial mais frequente em humanos. Estima-se que a incidência seja de 4:1.000 nascimentos no Brasil. Programas específicos para atendimento clínico de pacientes com perda auditiva são escassos no Brasil e a questão é um importante problema de saúde pública. Objetivo: Determinar a frequência das mutações 35delG no gene GJB2 e D13S1830 no GJB6 em pacientes deficientes auditivos de origem neurossensorial e não sindrômica de Minas Gerais, Brasil. Método: A pesquisa envolveu 53 indivíduos selecionados por meio de questionário o qual avaliou a possibilidade de surdez não sindrômica entre outros dados. As amostras foram testadas quanto à presença da mutação 35delG no gene GJB2 e D13S1830 no gene GJB6 por reação em cadeia da polimerase e digestão com enzima de restrição. Resultados: A pesquisa epidemiológica mostrou que a maioria dos indivíduos desconhece a etiologia da perda auditiva. Em 9 pacientes (16,98%), a mutação 35delG foi encontrada em heterozigose e a frequência alélica foi estimada em 8,5%. Embora 9,61% das pessoas tenham relatado algum grau de consanguinidade entre os pais e 12,08% relatassem outros casos de surdez em suas famílias, essa mutação não foi encontrada em homozigose. A mutação D13S1830 não foi encontrada neste estudo. Conclusão: Este trabalho descreve pela primeira vez a frequência da mutação 35delG e D13S1830 em deficientes auditivos de Minas Gerais, Brasil, e os dados coletados reforçam a necessidade de mais estudos nessa população devido à heterogeneidade da perda auditiva.
Assuntos
Humanos , Masculino , Feminino , Pré-Escolar , Criança , Adolescente , Adulto , Adulto Jovem , Perda Auditiva Neurossensorial/genética , Mutação/genética , Reação em Cadeia da Polimerase , GenótipoRESUMO
This study aims to perform the first molecular and clinical-epidemiological analysis of dengue cases in Divinopolis, MG, Brazil. Data from 4,110 cases of dengue were accessed and 190 clinical samples were collected for molecular analyses. In this study, 2.7% of the men and 3.0% of the women were admitted to hospital. There was no association between gender and hospital admission. The symptoms observed in this study are according to the Health Ministry, but fever was present in 82.2% and not in 100% of cases. The chance of hospital admission was 1.55 higher in patients with any kind of bleeding (334) and 2.4% of individuals without bleeding were also hospitalized due to other warning signs. In the molecular analyses, 23% of the samples were positive for DENV. DENV-2 and DENV-3 were identified in 2010, DENV-3 in 2011, DENV-1 in 2012, and DENV-1 and DENV-4 in 2013. DENV detection was possible in samples with only one day of symptoms. This first report of dengue data in Divinópolis provided more insight into the viral types and effects of disease in the city, confirming the need for caution in assessing cases of suspected dengue and for revision of the criteria proposed by the Health Ministry to classify cases of the disease.