Influência dos polimorfismos para o gene da sintase do óxido nitrico endotelial (eNOS) na pressão arterial e perfil lipídico em resposta ao treinamento físico em mulheres no climatério

A incidência de doenças cardiovasculares tem se constituído na maior causa de morbimortalidade em todo mundo, especialmente após os 50 anos de idade, e têm sido associadas à presença de polimorfismos em alguns genes, especialmente o gene da eNOS. Apesar das mulheres compartilharem com os homens os diversos fatores de risco para o desenvolvimento das doenças cardiovasculares, entre elas hipertensão arterial e dislipidemia, estudos epidemiológicos mostram que as mesmas, antes da menopausa, apresentam menor risco cardiovascular quando comparadas aos homens. Entretanto, após o período da menopausa há um aumento significativo na incidência de hipertensão arterial e suas complicações. Este fato parece estar relacionado a uma possível ação protetora exercida pelos hormônios sexuais femininos, sobretudo os estrogênios que apresentam queda abrupta no período da menopausa. O óxido nítrico (NO), produzido pelas células endoteliais através da enzima eNOS, desempenha importante papel no sistema cardiovascular, participando na regulação do fluxo sanguíneo, do remodelamento vascular e na atividade plaquetária. Assim, estudos envolvendo o gene responsável pela síntese da enzima eNOS, tem sido foco de várias pesquisas na tentativa de avaliar se a presença dos polimorfismos poderia predispor os indivíduos a maior incidência de doenças cardiovasculares. O polimorfismo do gene da eNOS na posição G894T/Glu298Asp localizado no éxon 7, implica na alteração da sequência protéica, tornando a proteína mais suscetível à clivagem, tendo consequências funcionais como a redução do NO demonstrando assim sua provável contribuição para a disfunção endotelial e consequente aumento da pressão arterial. Com relação ao Íntron 4 caracterizado por um Número Variável de Repetições em Tandem... (Resumo completo, clicar acesso eletrônico abaixo)

Polimorfismos do gene da eNOS: relação com hipertensão arterial em diferentes níveis de atividade física em adultos

A gênese da hipertensão arterial têm sido associada à presença de polimorfismos em alguns genes, em específico no gene da eNOS. O polimorfismo no Íntron 4 é caracterizado por um Número Variável de Repetições em Tandem, no qual o alelo 4a foi relacionado a baixos níveis de nitrito/nitrato. Os indivíduos 4a/a exibiram 20% menos óxido nítrico (NO) que os indivíduos com genótipos 4b/b, assim como diminuições na expressão protéica da eNOS. Acredita-se que a alteração polimórfica de único nucleotídeo (SNP), na posição - 786 do gene da eNOS esteja relacionada à modulação do gene através da ação de uma proteína repressora chamada de RPA1, capaz de diminuir a quantidade de mRNA, e nitrito/nitrato plasmático; demonstrando sua provável contribuição para o aumento dos valores de pressão arterial. Apenas dois trabalhos mostram uma associação entre os polimorfismos do Intron 4 e -786, demonstrando que o 4a/4a apresenta uma possível ligação de desequilíbrio com a posição -786, sugerindo uma associação positiva entre polimorfismos e prevalência de espasmos coronários e redução na produção endotelial de NO. No entanto, nenhum trabalho avaliou a associação entre o nível de atividade física e a presença de polimorfismo no Íntron 4 e -786 juntos. Assim, os objetivos deste trabalho foram: verificar se existe relação entre a prevalência de hipertensão arterial e a presença do polimorfismo para o gene da eNOS nas duas posições - 786 e Íntron 4, separadamente e juntamente, em voluntários acima de 40 anos e também avaliar se existe relação entre o nível de atividade física e os valores de pressão arterial em indivíduos com e sem estes polimorfismos. Para a análise genética foram feitas análises de reação em cadeia da polimerase (PCR) e para a classificação dos níveis de atividade...(Resumo completo, clicar acesso eletrônico abaixo)

Characterization and polymorphism screening of IGF-I and prolactin genes in Nelore heifers

Insulin growth factor I (IGF-I) and prolactin (PRL) are peptide hormones that exert complementary effects on reproductive traits by acting on folliculogenesis. In view of the lack of information about the IGF-I and PRL genes in Bos indicus, the objective of this study was to partially characterize the promoter regions of these genes and to screen animals of different ages at first pregnancy for the presence of polymorphisms in these regions. In addition, we determined whether polymorphisms influence the regulation of the two hormone genes, evaluating their association with sexual precocity.The animals were divided into three groups according to age at first pregnancy: 1) 100 heifers considered to be sexually precocious that became pregnant at 15-16 months of age, 2) 100 heifers that became pregnant during the normal breeding season at 24 months of age, and 3) 100 heifers that did not become pregnant until 24 months of age. For the IGF-I gene, PCR-RFLP-SnaBI analysis showed the presence of genotypes AB and BB at frequencies of 0.02 and 0.98, respectively. Sequencing of the IGF-I gene fragment revealed a single nitrogen base change from cytosine to thymine, corresponding to the restriction site of SnaBI. The polymorphisms identified in the 5'-flanking region of the IGF-I gene may serve as a basis for future studies of molecular markers in cattle. For the PRL gene, PCR-RFLP-HaeIII analysis showed the presence of only one migration pattern, a finding characterizing the region studied as monomorphic. The study of other regions in the IGF-I and PRL genes might provide molecular data that can be used in the future for the selection of sexually precocious animals.

Assessment of DGAT1 and LEP gene polymorphisms in three Nelore (Bos indicus) lines selected for growth and their relationship with growth and carcass traits

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Associations of FASN gene polymorphisms with economical traits in Nellore cattle (Bos primigenius indicus)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hydrocephalus and moderate mental retardation in a boy with Van der Woude phenotype and IRF6 gene mutation

In this report, we present a boy with lower lip pits, distinct craniofacial dysmorphism with cleft lip and palate, central nervous system malformation, and severe mental retardation. Similar but less pronounced facial findings were present in his mentally normal mother and maternal grandfather, both presenting with lower lip pits. Cleft lip was present in patient's father. Analysis of the VWS1 and VWS2 regions were performed to elucidate the molecular basis of the phenotype of the propositus. Screening or mutations at the IRF6 gene detected a pathogenic mutation (c.960G > C) in the propositus and in his mother; and a single nucleotide polymorphism (c.175-5C > G) in the propositus and in his father. Clinical and genetic aspects of this case are discussed.

EBNA-1 gene sequences in Brazilian and American patients with Hodgkin's disease

We examined the types of Epstein-Barr virus-associated nuclear antigen-1 (EBNA-1) gene carboxy (C)-terminal mutations occurring in Hodgkin's disease (HD) and reactive tissues from two different geographic regions. Previously reported EBNA-1 C-terminal region amino acid sequence variants, based on the amino acid at codon 487, include Prototype (P)-ala, which is found in the B95.8-derived prototype virus, P-thr, Variant (V)-leu, V-val, and V-pro. Using polymerase chain reaction (PCR) to amplify portions of the EBNA-1 gene, followed by DNA sequencing, we found a single EBNA-1 gene sequence variant in each tissue, whether reactive or neoplastic and whether from Brazil or the United States. Variant EBNA-1 gene sequences were more common in both neoplastic and non-neoplastic tissues from different geographic areas than the so-called prototype sequence. In the 17 Brazilian HD cases, 4 cases had P-thr variants and 13 had V-leu variants. In the six reactive tissues from Brazil, one had a P-ala variant, two had P-thr variants, and three had V-leu variants. In the 12 American HD cases, 2 had P-ala variants, 6 had P-thr variants, and 4 had V-leu variants. The 11 American reactive tissues included 2 P ala variants, 5 P-thr variants, and 4 V-leu variants. In both countries, there were similar variant EBNA-1 sequences present in normal tissues and HD cases. Compared with the P ala and P-thr cases, the V-leu cases were more likely to have the 30-bp latent membrane protein 1 (LMP1) gene deletion (P = 0.0075). In addition, cases of HD with the V-leu were statistically associated with a substitution of asparagine for glutamine at codon 322 of the C-terminal portion of the LMP1 gene. Our results suggest that any variation in EBNA-1 gene sequence is caused by a polymorphism present in pre-existing viral strains in the underlying population, and not a mutation occurring during oncogenesis. (C) 1999 by the American Society of Hematology.

Typing class I HLA-A gene using a nested PCR-RFLP procedure

In order to detect several new HLA-A class I alleles that have been described since 1998, the original PCR-RFLP method developed to identify the 78 alleles recognized at that time at high resolution level was adapted by us for low and medium resolution levels using a nested PCR-RFLP approach. The results obtained from blood samples of 23 subjects using both the PCR-RFLP method and a commercial kit (MicroSSP1A®, One Lambda Inc.) showed an agreement higher than 95%. The PCR-RFLP adapted method was effective in low and medium resolution histocompatibility evaluations.

PSA and androgen-related gene (AR, CYP17, and CYP19) polymorphisms and the risk of adenocarcinoma at prostate biopsy

The aim of the present study was to examine the impact of polymorphisms in prostate-specific antigen (PSA) and androgen-related genes (AR, CYP17, and CYP19) on prostate cancer (PCa) risk in selected high-risk patients who underwent prostate biopsy. Blood samples and prostate tissues were obtained for DNA analysis. Single-nucleotide polymorphisms in the 50-untranslated regions (UTRs) of the PSA (substitution A > G at position -158) and CYP17 (substitution T > C at 50-UTR) genes were detected by polymerase chain reaction (PCR)-restriction fragment length polymorphism assays. The CAG and TTTA repeats in the AR and CYP19 genes, respectively, were genotyped by PCR-based GeneScan analysis. Patients with the GG genotype of the PSA gene had a higher risk of PCa than those with the AG or AA genotype (OR = 3.79, p = 0.00138). The AA genotype was associated with lower PSA levels (6.44 +/- 1.64 ng/mL) compared with genotypes having at least one G allele (10.44 +/- 10.06 ng/mL) (p = 0.0687, 95% CI - 0.3146 to 8.315, unpaired t-test). The multivariate analysis confirmed the association between PSA levels and PSA genotypes (AA vs. AG+GG; chi(2) = 0.0482) and CYP19 (short alleles homozygous vs. at least one long allele; chi(2) = 0.0110) genotypes. Genetic instability at the AR locus leading to somatic mosaicism was detected in one PCa patient by comparing the length of AR CAG repeats in matched peripheral blood and prostate biopsy cores. Taken together, these findings suggest that the PSA genotype should be a clinically relevant biomarker to predict the PCa risk.

Shorter CAG repeat length in the AR gene is associated with poor outcome in head and neck cancer

Objective: Alterations in the size of the [CAG](n) repeats of the AR gene have been described in several types tumors. The purpose of this study was to evaluate if there is an association between the AR [CAG](n) repeat alleles and the relative risk for head and neck cancer and to analyse microsatellite instability (MSI) and loss of heterozygosity (LOH) in these tumors.Design: Matched samples of blood and head and neck tumors were evaluated using two methodologies, silver-stained gels to perform the analyses of MSI and LOH, and automated analysis to confirm these results and for genotyping of the AR [CAG](n), repeat length. Sixty-nine individuals without cancer were used as a control group for both procedures. The Log-rank test was used to compare overall survival and disease-free survival curves. The Cox proportional hazards regression models were performed to determine the [CAG], repeats as an independent prognostic factor.Results: Patients with alleles <= 20 in the male group showed a correlation with lower disease-free survival (P = 0.0325) and with recurrence or metastasis (RR 2.52, CI 95%). in the female group, the allele 2 (longer allele) showed a significant lower mean of [CAG](n), repeat when compared to the control group. Microsatellite instability was detected in nine cases in both procedures. In six out of these nine cases, we observed a reduction of the AR [CAG](n) repeat length. LOH was detected in one out of 17 women informative for oral cancer in both procedures.Conclusion: These results suggest that short [CAG](n) repeat length (: 20) polymorphism is associated with poor prognosis in a subset of male patients with head and neck cancer and that AR gene microsatellite instability is uncommon in these tumors. (C) 2007 Elsevier Ltd. All rights reserved.

Identification and characterization of polymorphisms within the 5' flanking region, first exon and part of first intron of bovine GH gene

The aim of the present study was to identify and characterize polymorphisms within the 5' flanking region, first exon and part of first intron of the bovine growth hormone gene among different beef cattle breeds: Nelore (n = 25), Simmental (n = 39), Simbrasil (n = 24), Simmental x Nelore (n = 30), Canchim x Nelore (n = 30) and Angus x Nelore (n = 30). Two DNA fragments (GH1, 464 bp and GH2, 453 bp) were amplified by polymerase chain reaction and then used for polymorphism identification by SSCP. Within the GH1 fragment, five polymorphisms were identified, corresponding to three different alleles: GH1.1, GH1.2 and GH1.3 (GenBank: AY662648, AY662649 and AY662650, respectively). These allele sequences were aligned and compared with bovine GH gene nucleotide sequence (GenBank: M57764 and AF118837), resulting in the identification of five insertion/deletions (INDELs) and five single nucleotide polymorphisms (SNPs). In the GH2 fragment two alleles were identified, GH2.1 and GH2.2 (GenBank: AY662651 and AY662652, respectively). The allele sequences were compared with GenBank sequences (M57764, AF007750 and AH009106) and three INDELs and four SNPs were identified. In conclusion, we were able to identify six new polymorphisms of the bovine GH gene (one INDEL and five SNPs), which can be used as molecular markers in genetic studies.

Association between IGF-I, IGF-IR and GHRH gene polymorphisms and growth and carcass traits in beef cattle

Molecular biology techniques are of help in genetic improvement since they permit the identification, mapping and analysis of polymorphisms of genes encoding proteins that act on metabolic pathways involved in economically interesting traits. The somatotrophic axis, which essentially consists of growth hormone releasing hormone (GHRH), growth hormone (GH), insulin-like growth factors I and II (IGF-I and IGF-II), and their associated binding proteins and receptors (GHRHR, GHR, IGF-IR and IGF-IIR), plays a key role in the metabolism and physiology of mammalian growth. The objectives of the present study were to estimate the allele and genotype frequencies of the IGF-I/SnaBI, IGF-IR/TaqI and GHRH/HaeIII gene polymorphisms in different genetic groups of beef cattle and to determine associations between these polymorphisms and growth and carcass traits. For this purpose, genotyping was performed on 79 Nellore animals, 30 Canchim (5/8 Charolais+3/8 Zebu) animals and 275 crossbred cattle originating from the crosses of Simmental (n=30) and Angus (n=245) sires with Nellore females. In the association studies, traits of interest were analyzed using the GLM procedure of SAS and least square means of the genotypes were compared by the Tukey test. Associations of IGF-I/SnaBI genotypes with body weight and subcutaneous backfat were significant (p < 0.05), and nearly significant for longissimus dorsi area (p=0.06), with the 1313 genotype being favorable compared to the AB genotype. No significant associations were observed between this polymorphism and weight gain or carcass yield (P > 0.05). The IGF-IR/TaqI and GHRH/HaeIII polymorphisms showed no association with production traits. (c) 2004 Elsevier B.V All rights reserved.

Characterization of gene polymorphisms related to immune system physiology in Mangalarga horses

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Characterization and transcriptional analysis of the promoter region of the Duffy blood group, chemokine receptor (DARC) gene in cattle

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Associations between LEP, DGAT1 and FABP4 gene polymorphisms and carcass and meat traits in Nelore and crossbred beef cattle

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)