effects of estrogen receptor gene-alpha polymorphism on bone mineral density and serum osteoprotegerin levels in postmenopausal Egyptian women

The gene coding for estrogen receptor-alpha [ER-a] is a potential candidate for the regulation of bone mineral density [BMD] in postmenopausal women. The present study was aimed at elucidating the role of two restriction fragment lengths Pvu II and Xba I polymorphisms of the ER-a gene as determinants of bone mineral density; special attention was paid to the correlation between serum osteoprotegerin [OPG] levels and BMD in different ER-a genotypes in postmenopausal [PM] Egyptian women. BMD was measured at the femur neck [FN-BMD]. ER-a gene polymorphisms were detected by PCR-RFLP. Serum OPG levels were measured by an enzyme linked immunosorbent assay. There were significant differences in BMD and OPG according to different genotypes of Pvu II Single-nucleotide polymorphism [SNP]. Carriers of the pp genotype were more likely to have lower BMD and lower OPG values than noncarriers. While there was no significant relationship between Xbal polymorphism and these variables. Postmenopausal [PM] women were stratified into; those with osteoporosis and those without osteoporosis. The difference in BMD and OPG among genotypes were significant in PM with osteoporosis. Further we confirmed that the frequency of p allele. and pp genotype of Pvu II polymorphism were significantly higher in PM with osteoporosis as compared to PMwithout osteoporosis. Xba I failed to show any significant difference in genotype and allele frequencies between the two groups. Genotypes modulate the relationships between BMD and OPG levels, in women with the PP [r=0.512, p<0.000l] and Pp [r=0.346, p<0.0009] genotypes but not in women with the other genotypes [p>0.05]. These results suggest that the Pvu II polymorphism of ER-a may be associated with the FN-BMD in PM Egyptian women. Further, P allele carriers supposed to protect against PM osteoporosis at least partly by increasing serum OPG

Frequencies of interleukin-6, GST and progesterone receptor gene polymorphisms in postmenopausal women with low bone mineral density / Frequência do polimorfismo da interleucina-6, GST, e dos receptores de progesterona em mulheres na pós-menopausa com baixa densidade mineral óssea

CONTEXT AND OBJECTIVE: Osteoporosis is a skeletal disorder characterized by low bone mineral density (BMD). Studies have shown that some of the genetic components relating to lower BMD may be detected by polymorphisms. Our aim was to evaluate the frequencies of interleukin-6, GST and progesterone receptor gene polymorphisms in postmenopausal women with low BMD. DESIGN AND SETTING: Cross-sectional study, conducted in a public university in São Paulo, Brazil. METHODS : We evaluated interleukin-6 (IL-6), progesterone receptor gene (PROGINS) and glutathione S-transferase (GST) polymorphisms in 110 postmenopausal women with no previous use of hormone therapy. Tests were performed using DNA-PCR, from oral scrapings. We used Student's t-test and a logistic regression model for statistical analysis. RESULTS : Regarding IL-6 polymorphism, 58.2% of the patients were homozygotes (GG) and 41.8% had allele C (heterozygote or mutant homozygote + GC or CC). PROGINS genotype polymorphism was absent in 79% (wild homozygote or P1/P1) and present in 20.9% (heterozygote or P1/P2). Regarding GSTM1 polymorphism, the allele (1/1) was present in 72.7% of the patients and was absent in 27.3%. We found that IL-6 polymorphism had statistically significant correlations with the L2-L4 T-score (P = 0.032) and with BMD (P = 0.005). Women with IL-6 polymorphism were 2.3 times more likely to have a L2-L4 T-score of less than -1, compared with those not presenting this polymorphism. CONCLUSION: IL-6 gene polymorphism was correlated with low BMD, whereas the PROGINS and GSTM1 polymorphisms did not show any correlation. .

CONTEXTO E OBJETIVO: A osteoporose é uma desordem esquelética caracterizada por baixa densidade mineral óssea. Estudos têm demonstrado que alguns componentes genéticos relacionados com a menor densidade mineral óssea podem ser detectados por polimorfismos. Nosso objetivo foi avaliar a presença do polimorfismo de genes em mulheres pós-menopáusicas com baixa densidade mineral óssea. TIPO DE ESTUDO E LOCAL: Estudo transversal, conduzido em universidade pública em São Paulo, Brasil. MÉTODOS: Avaliamos os polimorfismos relacionados à interleucina-6 (IL-6), o gene receptor de progesterona (PROGINS) e glutationa S-transferase (GST) em 110 mulheres na pós-menopausa sem terapia hormonal prévia. Os testes foram realizados com DNA-PCR a partir de raspados orais. Foram utilizados teste t de Student e modelo de regressão logística para análise estatística. RESULTADOS: Em relação ao polimorfismo IL-6, 58,2% dos pacientes eram homozigotos (GG) e 41,8% tinham o alelo C (heterozigoto ou homozigoto mutante + GC ou CC). Nos genótipos do polimorfismo PROGINS, 79% estavam ausentes (homozigoto selvagem ou P1/P1) e 20,9% presentes (heterozigoto ou P1/P2). No polimorfismo do GSTM1, o alelo (1/1) estava presente em 72,7% dos pacientes e ausente em 27,3%. Encontramos significância estatística entre o polimorfismo genético da IL-6 com o T-score de L2-L4 (P = 0,032) e a densidade mineral óssea (P = 0,005). As mulheres com polimorfismo da IL-6 tiveram 2,3 vezes mais chance de ter menos de -1 na L2-L4 T-score, quando comparadas às não portadoras. CONCLUSÃO: O polimorfismo do gene da IL-6 está correlacionado com baixa densidade mineral óssea, enquanto os polimorfismos GSTM1 e PROGINS não mostraram correlação. .

Mayor frecuencia de aberraciones cromosómicas en linfocitos expuestos o no a mitomicina C, de mujeres posmenopáusicas obesas en comparación con mujeres no obesas del departamento del Cauca, Colombia / High frequency of chromosome aberrations observed in lymphocytes in postmenopausal obese women

Introducción. Los estudios epidemiológicos indican que la obesidad está asociada en el 25 al 30 % con varios tipos de cáncer. Objetivo. Evaluar la frecuencia de aberraciones cromosómicas en linfocitos de mujeres posmenopáusicas obesas y no obesas, mediante la prueba de reto celular (challenge assay) como biomarcador de inestabilidad genómica. Materiales y métodos. Cuarenta mujeres posmenopáusicas fueron incluidas en el estudio (20 obesas y 20 no obesas). Los grupos fueron pareados según edad (± 5 años) y procedencia. Después de la firma voluntaria del consentimiento informado, las mujeres fueron entrevistadas y se les tomó una muestra de 5 ml de sangre periférica. Se establecieron cultivos de linfocitos con tratamiento con mitomicina C y sin él (prueba de reto celular) y, posteriormente, se registró la frecuencia de aberraciones cromosómicas para cada grupo y tratamiento. Resultados. En general, las mujeres obesas presentaron una mayor frecuencia de aberraciones cromosómicas en comparación con las no obesas. Después de exponer los cultivos celulares a mitomicina C, las mujeres obesas presentaron un incremento en el número de aberraciones cromosómicas totales en comparación con las no obesas (3,74±0,63 Vs. 2,70±0,61; p=0,001). Conclusiones. La mayor frecuencia de aberraciones cromosómicas en los linfocitos de mujeres posmenopáusicas obesas que en no obesas, sugiere diferencias en la capacidad de reparación del ADN, lo cual podría explicar la asociación entre la inestabilidad genómica y la mayor incidencia de cáncer en esta población.

Introduction. Epidemiological studies indicate that obesity is associated with an increased risk of 20-25% with several types of cancer. Objective. The frequency of chromosome aberrations was evaluated in lymphocytes from postmenopausal obese and non-obese women. Materials and methods. Twenty obese and 20 non-obese women, all post-menopause, were recruited. The groups were matched according to age (± 5 years) and place of origin. After signing the consent form, women were interviewed using a structured questionnaire, and a blood sample (5 ml) was drawn into vacutainer tubes. From each sample, lymphocyte cell cultures were established with and without mitomycin C (challenge assay). Afterwards, the frequency of chromosome aberrations were recorded for each group and treatment. Data were analyzed using the statistical program SPSS, v. 14.0. Results. Obese women had a higher frequency of chromosome aberrations when compared with non-obese women. After exposing the cell cultures to mitomycin C, obese women presented an increase in the number of total chromosome aberrations in comparison to non-obese women (3.7± 0.6 vs. 2.70±0.6; p=0.001). Conclusions. The higher frequency of chromosome aberrations in lymphocytes from postmenopausal obese women compared to non-obese women suggested differences in the DNA repair capacity. This may indicate an association between genomic instability and the higher incidence of cancer in this population.

Influence of eNOS gene polymorphism on cardiometabolic parameters in response to physical training in postmenopausal women

The health-promoting effects of exercise training (ET) are related to nitric oxide (NO) production and/or its bioavailability. The objective of this study was to determine whether single nucleotide polymorphism of the endothelial NO synthase (eNOS) gene at positions -786T>C, G894T (Glu298Asp) and at the variable number of tandem repeat (VNTR) Intron 4b/a would interfere with the cardiometabolic responses of postmenopausal women submitted to physical training. Forty-nine postmenopausal women were trained in sessions of 30-40 min, 3 days a week for 8 weeks. Genotypes, oxidative stress status and cardiometabolic parameters were then evaluated in a double-blind design. Both systolic and diastolic blood pressure values were significantly reduced after ET, which was genotype-independent. However, women without eNOS gene polymorphism at position -786T>C (TT genotype) and Intron 4b/a (bb genotype) presented a better reduction of total cholesterol levels (-786T>C: before = 213 ± 12.1, after = 159.8 ± 14.4, Δ = -24.9 percent and Intron 4b/a: before = 211.8 ± 7.4, after = 180.12 ± 6.4 mg/dL, Δ = -15 percent), and LDL cholesterol (-786T>C: before = 146.1 ± 13.3, after = 82.8 ± 9.2, Δ = -43.3 percent and Intron 4b/a: before = 143.2 ± 8, after = 102.7 ± 5.8 mg/dL, Δ = -28.3 percent) in response to ET compared to those who carried the mutant allele. Superoxide dismutase activity was significantly increased in trained women whereas no changes were observed in malondialdehyde levels. Women without eNOS gene polymorphism at position -786T>C and Intron 4b/a showed a greater reduction of plasma cholesterol levels in response to ET. Furthermore, no genotype influence was observed on arterial blood pressure or oxidative stress status in this population.

Estudo do marcador genético de osteoporose COLI AI, atraves de diferentes enzimas de restrição, em mulheres climatericas brasileiras / Osteoporosis genetic markers study (COLI AI) with diferent restrictions enzimes, in Brazilian climateric women

Os objetivos do trabalho foram estudar o polimorfismo do gene do colageno tipo alfa 1 (COLI AI) como marcador genetico, comparado a densidade mineral...