Estrogen receptor alpha promoter polymorphism: stronger estrogen action is coupled with lower sperm count

BACKGROUND: Although the importance of estrogens in male reproduction is indisputable, little attention has been paid to the role of estrogen receptor (ER) gene mutations in male infertility. Significant correlation between (TA)n repeat allelic variants and lumbar bone mineral density was previously observed in the promoter region of the ERalpha gene, indicating that allelic combinations with higher number of (TA)n repeats are functionally more active genetic variants. METHODS: We studied the (TA)n repeat polymorphism situated in the promoter region of the ERalpha gene in a large group of infertile and normospermic men (n = 347). RESULTS: Although the (TA)n polymorphism failed to show a significant association with male infertility, we found a significant effect of this polymorphism on sperm count. In the group of infertile men, the mean TA repeat number and sperm concentration (P = 0.022) and total sperm number (P = 0.043) were inversely correlated, showing an association between higher TA repeat number (genotype A) and lower sperm production. In line with this observation, normospermic subjects with genotype A had a significantly lower mean sperm concentration with respect to men bearing genotype B with shorter TA alleles (P < 0.05) and a lower total sperm count (P < 0.01). CONCLUSIONS: Our data indicate that specific allelic combinations of the ERalpha, which confer a stronger estrogen effect, may negatively influence human spermatogenesis.     

Estrogen receptor alpha gene polymorphisms are associated with changes in bone remodeling markers and treatment response to estrogen

OBJECTIVES: Association studies between estrogen receptor alpha (ERalpha) gene polymorphisms and bone mineral density (BMD) have yielded inconsistent results. In the present study we evaluated the influence of XbaI and PvuII ERalpha gene polymorphisms on BMD, biochemical markers, rates of bone loss and the response to estrogen/hormone therapy (ET/HT) in elderly postmenopausal women. METHODS: At baseline, we measured the association between ERalpha genotypes and BMD and biochemical markers in 489 elderly women, mean age 71 +/- 3 years. In the longitudinal study, the changes in the same measures were determined in 96 women on placebo and in 79 women receiving the ET/HT for 3 years. The XbaI and PvuII ERalpha polymorphisms were determined by polymerase chain reaction (PCR). BMD measurements for spine, femoral neck and total body were performed by DEXA, and biochemical indices were measured by standard methods. RESULTS: Neither the PvuII nor the XbaI ERalpha gene polymorphisms were associated with baseline BMD and biochemical indices. In the longitudinal study, there were trends for higher bone loss in the placebo group in the genotypes pp or xx compared to PP or XX genotypes, but the changes were not significant. However, the changes in the bone markers were significantly (p < 0.05) higher in genotype group pp compared to PP (serum osteocalcin, 4.9 +/- 7.0% versus -13.4 +/- 6.7%; urine NTx:Cr ratio, 32.3+/-10.3% versus -2.5 +/- 10.3%) or xx compared to XX (serum osteocalcin, 7.5 +/- 6.4% versus -15.6+/-7.3%; urine NTx:Cr ratio, 39.4 +/- 9.2% versus -8.84+/-10.7%). At the end of 3 years, the mean urine NTx:Cr ratio was 78.7 +/- 9.0 versus 44.6 +/- 4.9 in pp versus PP (p < 0.05) and 75.5 +/- 10.7 versus 48.7 +/- 5.4 in xx versus XX (p < 0.05) genotypes. The response in total body BMD to ET/HT treatment was significantly higher in women with the PP genotype compared to pp genotype (2.48 +/- 0.55% versus 0.66 +/- 0.46%). Similar trends were seen at other skeletal sites for both XX and PP compared to pp and xx genotypes. CONCLUSION: Women with ERalpha, PP and XX genotypes have lower bone remodeling, lower rates of bone loss and benefit more from hormone therapy.     

Association of 5' estrogen receptor alpha gene polymorphisms with bone mineral density,vertebral bone area and fracture risk

This study investigates the influence of genetic variation of the estrogen receptor alpha (ESR1) gene locus on several bone parameters in 2042 individuals of The Rotterdam Study, a prospective population-based cohort study of elderly subjects. We analysed three polymorphic sites in the 5' region of the ESR1 gene; a (TA)(n)-repeat in the promoter region, and molecular haplotypes of the PvuII and XbaI RFLPs in intron 1, and inferred long-range haplotypes (LRH) thereof. We observed only three of the possible four PvuII-XbaI haplotypes in our population. A comparison with other Caucasian populations showed similar haplotype frequencies, while in Asian and African populations these were different. Linkage disequilibrium (LD) analysis between the PvuII-XbaI haplotype and the (TA)(n) repeat showed strong LD between the two sites. Reconstruction of long range haplotypes over the entire 5' region, revealed six frequent LRH. In men, we did not observe an association between the ESR1 polymorphisms studied and bone parameters. In women, we demonstrated an allele dose effect of haplotype "px" (P=0.003) and a low number of (TA)(n) repeats (P=0.008) with decreased lumbar spine bone mineral density (BMD) (4.8% lower BMD in women homozygous for haplotype "px", representing 28% of the population, compared with homozygous non-carriers) and decreased vertebral bone area (2.3% difference between extreme genotypes; P=0.016). Most importantly, we found an increased vertebral fracture risk with evidence for an allele dose effect with an odds ratio of 2.2 (95%CI 1.3-3.5) for haplotype "px", and 2.0 (1.5-3.2) for a low number of (TA)(n) repeats. The ESR1 genotype dependent fracture risk is largely independent of BMD and bone area. Combination of risk alleles at both loci by long-range haplotyping improved the associations slightly, but because of the strong LD between the two polymorphic sites, we were unable to determine if any particular polymorphic site is driving the associations found. We conclude that ESR1 polymorphism in the 5' (promoter) region is associated with vertebral fracture risk, lumbar spine BMD and vertebral bone area in postmenopausal women, but not in men. The molecular mechanism underlying this association needs further study.     

Relation of the estrogen receptor alpha gene microsatellite polymorphism to bone mineral density and the susceptibility to osteoporosis in postmenopausal Chinese women in Taiwan.

OBJECTIVE: Osteoporosis is a common disorder with a strong genetic component. Our aim was to investigate the correlation of the estrogen receptor alpha gene microsatellite polymorphism (TA dinucleotide repeat polymorphism 5' upstream of exon 1) with bone mineral density and their relationship to osteoporosis. METHODS: We determined the estrogen receptor alpha gene microsatellite polymorphism using polymerase chain reaction-based microsatellite analysis in postmenopausal Chinese women in Taiwan. Bone mineral density of the lumbar spine and proximal femur were measured using dual-energy X-ray absorptiometry. RESULTS: The ERalpha genotype was classified into '12' through '27' according to the number of TA dinucleotide repeats they contained, as a 'signpost'. After adjustment for potential confounding factors including age, height, and weight, subjects with genotype 18+ (n=4) had lower bone mineral density values and a 54.5 times greater risk for osteoporosis when compared with subjects with genotype 18- (n=170) at the lumbar spine. This should be interpreted with caution because of the small number of subjects with the unfavorable genotype 18+. According to mean number of TA dinucleotide repeats, women with a high number of repeats (TA > or =20) (n=38) had the lowest bone mineral density and a 6.1 times greater risk for osteoporosis than women with a low number of repeats (TA < or =15) (n=61) at the femoral neck, after adjustment for potential confounding factors such as age, height, and weight. CONCLUSION: The present study suggests that the estrogen receptor alpha gene microsatellite polymorphism may be a candidate genetic marker for risk of osteoporosis in postmenopausal Chinese women in Taiwan.     

雌激素受体1 基因rs2046210 位点多态性与乳腺癌患病风险性关系初步研究

目的: 探讨雌激素受体1 基因(Estrogen receptor 1,ESR1) 周围区域单核苷酸多态(Single nucleotide polymorphism,SNP)位点rs2046210 与女性乳腺癌发生的相关性。方法:选取114 例乳腺癌患者的组织切片和141 例健康对照者的外周血,抽提基因组DNA,采用Taqman 探针法检测SNP 位点rs2046210 的基因型,计算基因型与基因频率,先检测Hardy-Weinberg 平衡性,然后采用字2 检验进行组间比较。结果:经检测rs2046210 等位位点T、C 及其三种基因型CC、TC、TT 均符合Hardy-Weinberg 平衡性定律,具有群体代表性(字2 值分别为2.78、2.95,v=1,P 均>0.05)。等位位点T、C 在乳腺癌组的分布频率为43.40%、56.60%,在健康组的分布频率为38.30%、61.70%。两组比较差异无统计学意义(P<0.05),该位点等位基因在病例组与对照组的分布无明显差别。多态性位点的三种基因型CC、TC、TT 在乳腺癌的频率分别为35.75%、11.35% 和53.90%,对照组35.96%、22.81%和41.22%,两组间比较差异有显著统计学意义(P<0.05)。进一步比较发现,基因型CC/ TT在两组中分布差异无统计学意义(P>0.05),相对风险比值OR 为1.94(0.92 ~ 4.1,95% CI),基因型CC/ TC 在两组中分布差异无统计学意义(P =0.228>0.05),相对风险比值OR 为0.74(0.43 ~1.28,95%CI),而基因型TT/ TC 在两组中分布差异有显著统计学意义(P =0.008<0.05)。结论:在贵州地区人群,雌激素受体1 基因rs2046210 位点的单核苷酸多态性可能与乳腺癌的遗传易感性相关,特别是rs2046210 TT 基因型可能增加个体患乳腺癌的风险,而CC 基因型降低了乳腺癌的患病风险。     

Genetic estrogen receptor alpha gene PvuII polymorphism in susceptibility to knee osteoarthritis in a Chinese Han population: A southern Jiangsu study

BackgroundKnee osteoarthritis (KOA) is the most prevalent type of arthritis and genetic factors play an important role in KOA pathogenesis. Some studies have reported the association of estrogen receptor alpha (ESRα) gene polymorphism and KOA susceptibility in different populations. This study was designed to verify whether ESRα gene polymorphism (rs2234693) was associated with primary KOA in a Chinese Han population living in the south of Jiangsu.MethodsA case–control association study on single nucleotide polymorphism (SNP) rs2234693 was performed, and a total of 1953 subjects (1033 OA cases and 920 controls) were genotyped. Allele and genotype frequencies were compared between KOA cases and control participants.ResultsSNP rs2234693 was significantly associated with KOA in the dominant genetic model (TT + TC vs. CC) in all the subjects (odds ratio (OR) = 1.30; 95% confidence interval (CI) = 1.02–1.66; P = .03), and T allele frequency was also higher compared with allele C (OR = 1.38; 95% CI = 1.06–1.80; P = .02). After stratification by gender, there was no evident difference between the two groups in female and male subjects (P > .05). With a stratification for KOA severity, the combined genotype (TT + TC) (OR = 1.47; 95% CI = 1.12–1.94; P < .01) and T allele (OR = 1.61; 95% CI = 1.19–2.19; P < .01) were evidently associated with mild KOA, but not with severe KOA.ConclusionsESRα gene is of considerable importance in the pathogenesis of early-stage KOA in a Chinese Han population living in southern Jiangsu.     

Estrogen up-regulates estrogen receptor alpha and synaptophysin in slice cultures of rat hippocampus

Previous studies have shown that estrogen application increases the density of synaptic input and the number of spines on CA1 pyramidal neurons. Here, we have investigated whether Schaffer collaterals to CA1 pyramidal cells are involved in this estrogen-induced synaptogenesis on CA1 pyramidal neurons. To this end, we studied estrogen-induced expression of both estrogen receptor (ER) subtypes (ERalpha and ERbeta) together with the presynaptic marker synaptophysin in the rat hippocampus. In tissue sections as well as in slice cultures mRNA expression of ERalpha, ERbeta and synaptophysin was higher in CA3 than in CA1, and mRNA expression and immunoreactivity for both ER subtypes were found in both principal cells and interneurons. By using quantitative image analysis we found stronger nuclear immunoreactivity for ERalpha in CA3 than in CA1. In slice cultures, supplementation of the medium with 10(-8) M estradiol led to an increase of nuclear immunoreactivity for ERalpha, but not for ERbeta, which was accompanied by a dramatic up-regulation of synaptophysin immunoreactivity in stratum radiatum of CA1. Together these findings indicate that estrogen effects on hippocampal neurons are more pronounced in CA3 than in CA1 and that ER activation in CA3 neurons leads to an up-regulation of a presynaptic marker protein in the axons of these cells, the Schaffer collaterals. We conclude that estradiol-induced spine formation on CA1 pyramidal cells may be mediated presynaptically, very likely by activation of ERalpha in CA3 pyramidal cells, followed by an increase in Schaffer collateral synapses.     

Estrogen receptor alpha gene (ESR1) polymorphism and its interaction with smoking and drinking contribute to susceptibility of systemic lupus erythematosus

The aim of this study is to investigate the association of estrogen receptor alpha gene (ESR1) polymorphisms, additional gene–gene, and gene–environment interaction with systemic lupus erythematosus (SLE) risk. SNPStats (available online at http://bioinfo.iconcologia.net/SNPstats) was used to investigate the Hardy–Weinberg equilibrium (HWE) in controls and association between SNP and SLE risk. Generalized multifactor dimensionality reduction (GMDR) was used to screen the interactions among SNPs and environmental risk factors; SLE risk was significantly higher in carriers of rs2234693 C allele than those with TT (TC + CC versus TT), adjusted OR (95%CI) = 1.57 (1.21–2.06), and was also higher in carriers of rs9340799 G allele than those with AA (AG + GG versus AA), adjusted OR (95%CI) = 1.68 (1.24–2.13). However, we also find no association between rs2228480 and SLE risk after covariates adjustment. We found a significant two-locus model (p = 0.0010) involving rs2234693 and smoking; the cross-validation consistency of this model was 10/10, and the testing accuracy was 62.70%. Smokers with TC or CC of rs2234693 genotype have the highest SLE risk, compared to never-smokers with TT of rs2234693 genotype, OR (95%CI) was 2.50 (1.65–3.42), after covariates adjustment for gender, age, alcohol drinking, and BMI. We found that C allele of rs2234693 and G allele of rs9340799 within ESR1 gene, their interaction between rs2234693 and current smoking were all associated with increased SLE risk.     

Estrogen receptor alpha gene polymorphism in schizophrenia: frequency, age at onset, symptomatology and prognosis

Schizophrenic disorders are equally distributed for both sexes; however, later onset, milder psychopathology and better outcome are associated with the female gender. This sex difference is thought to be partly due to the estrogen system. Recent studies have determined that estrogen receptor alpha subtype (ER alpha) genetic polymorphisms may affect the expression of ER alpha, and are associated with Alzheimer's disease. For this study, we investigated the association of ER alpha polymorphisms for 125 schizophrenic patients and 142 control subjects. No significant differences for genotype distribution or allele frequency were revealed comparing controls and schizophrenic patients. The ER alpha genotypes were not associated with onset age, psychiatric symptoms or outcome for schizophrenic cases. With new research highlighting the prominent role of sex hormones in neurological and psychological dysfunction, further study is needed to explore the genetic effect of the sex hormone receptor gene on susceptibility mental disorders and associations with different phenotypes.     

Single-nucleotide polymorphisms in the P2X7 receptor gene are associated with post-menopausal bone loss and vertebral fractures

The purinergic P2X7 receptor has a major role in the regulation of osteoblast and osteoclast activity and changes in receptor function may therefore affect bone mass in vivo. The aim of this study was to determine the association of non-synonymous single-nucleotide polymorphisms in the P2RX7 gene to bone mass and fracture incidence in post-menopausal women. A total of 1694 women (aged 45-58) participating in the Danish Osteoporosis Prevention Study were genotyped for 12 functional P2X7 receptor variants. Bone mineral density was determined at baseline and after 10 years. In addition, vertebral fracture incidence was documented at 10 years. We found that the rate of bone loss was clearly associated with the Arg307Gln amino acid substitution such that individuals heterozygous for this polymorphism had a 40% increased rate of bone loss. Furthermore, individuals carrying the Ile568Asn variant allele had increased bone loss. In contrast, the Gln460Arg polymorphism was associated with protection against bone loss. The Ala348Thr polymorphism was associated with a lower vertebral fracture incidence 10 years after menopause. Finally, we developed a risk model, which integrated P2RX7 genotypes. Using this model, we found a clear association between the low-risk (high-P2X7 function) alleles and low rate of bone loss. Conversely, high-risk (reduced P2X7 function) alleles were associated with a high rate of bone loss. In conclusion, an association was demonstrated between variants that reduce P2X7 receptor function and increased rate of bone loss. These data support that the P2X7 receptor is important in regulation of bone mass.     

Mutagen sensitivity as a susceptibility marker for endometriosis

BACKGROUND: The mutagen sensitivity assay has been well established and widely used as a good independent risk predictor for developing cancers. Although endometriosis is considered a benign disorder, it exhibits several features similar to malignancy. The objectives of this study were to evaluate whether mutagen sensitivity can predict the risk of endometriosis development. METHODS: The subjects were women undergoing different surgical procedures due to different stages of endometriosis. Bleomycin was used as a mutagen, and the mutagen sensitivity of peripheral lymphocytes from women with and without endometriosis was determined by measuring chromatid breaks induced by bleomycin in short-term culture using cytogenetic analysis. RESULTS: The mean +/- SD (range) number of chromatid breaks per cell in women with and without endometriosis was 0.68 +/- 0.12 (0.50-0.94) and 0.52 +/- 0.10 (0.35-0.68), respectively. There was a significant difference with regard to mean chromatid breaks per cell between women with and without endometriosis (P < 0.001). On logistic regression analysis, the odds ratio (95% confidence interval) of chromatid breaks per cell was 5.80 (2.19-15.37, P < 0.001) for cases compared with controls. Yet, variables of interest including age, dysmenorrhoea, previous induced abortion and smoking in the home and workplace were not statistically correlated with chromatid breaks per cell. CONCLUSIONS: These preliminary data suggest that sensitivity to bleomycin-induced chromatid breaks in lymphocytes is associated with the risk of endometriosis development.     

Immunohistochemical analysis of estrogen receptor alpha, estrogen receptor beta and progesterone receptor in normal human endometrium

The endometrium expresses estrogen (ER) and progesterone receptors (PR), which are involved in autocrine and paracrine regulation processes in response to estrogen and progesterone. The aim of the present study was to evaluate immunohistochemical distribution patterns of estrogen receptor alpha (ER alpha), estrogen receptor beta (ER beta) and PR in normal human endometrial tissue with the use of monoclonal antibodies. Human endometria were obtained from 17 premenopausal patients undergoing surgery for non-malignant diseases and were classified to be in proliferative, early secretory and late secretory phases by histological and anamnestical means. Distribution patterns of the steroid receptors were evaluated using the IRS-score and the Mann-Whitney rank-sum test was used to compare the means. Correlation was assessed with the Spearman factor and linear regression analysis. ER alpha and PR expression decreased significantly (p<0.05) in glandular epithelium from the proliferative to the late secretory phase. ER beta expression showed a similar significant decrease (p<0.05), although staining intensity was lower than that of ER alpha. A significant correlation between expression of all three steroid receptors was observed (p<0.001). Distribution patterns of ER alpha, ER beta and PR in normal human endometrium showed a cyclic variation during the menstrual cycle. A significant correlation between expression of ER alpha, ER beta and PR was also demonstrated using regression analysis, indicating dependence of expression of these three steroid receptors. The present study shows the presence of steroid receptors in human endometrial epithelium, indicating that these cells respond to estrogen and progesterone and thus playing a significant role in endometrial physiology.     

雌激素受体基因多态性与老年妇女的骨密度

背景：雌激素受体α基因多态性与骨质疏松的发生相关有一定的关系,但是对于危险基因型的研究还存在商榷余地。 目的：分析雌激素受体基因多态性与老年妇女骨密度的相关性。 方法：选择检查的老年健康妇女120例,提取全血基因组DNA,选择限制性内切酶PvuⅡ和XbaⅠ进行酶切,分析基因型的分布与频率。同时选择双能X射线骨密度仪测股骨颈、大转子及Ward三角处的骨密度值。 结果与结论：XbaⅠ酶切基因型XX 6例,Xx 78例,xx 36例;PvuⅡ酶切PP 32例,Pp 50例,pp 38例。不同基因型老年妇女的年龄、绝经年龄与体质量指数值对比差异无显著性意义(P > 0.05)。PvuⅡ酶切PP基因型妇女的大转子与ward三角处的骨密度值明显大于Pp及pp妇女(P < 0.05);而XbaⅠ酶切基因多态性在老年妇女中股骨颈、大转子与Ward三角的骨密度均无显著差异(P > 0.05)。说明雌激素受体基因多态性与老年妇女骨密度有一定的相关性,P等位基因对老年妇女大转子与Ward三角处的骨密度的维持有一定作用。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

Association of oestrogen receptor alpha gene polymorphisms with postmenopausal bone loss, bone mass, and quantitative ultrasound properties of bone

Background: The gene encoding oestrogen receptor α (ESR1) appears to regulate bone mineral density (BMD) and other determinants of osteoporotic fracture risk.

Objective: To investigate the relation between common polymorphisms and haplotypes of the ESR1 gene and osteoporosis related phenotypes in a population based cohort of 3054 Scottish women.

Results: There was a significant association between a common haplotype "px", defined by the PvuII andXbaI restriction fragment length polymorphisms within intron 1 of the ESR1 gene, and femoral neck bone loss in postmenopausal women who had not received hormone replacement therapy (n = 945; p = 0.009). Annual rates of femoral neck bone loss were ~14% higher in subjects who carried one copy of px and 22% higher in those who carried two copies, compared with those who did not carry the px haplotype. The px haplotype was associated with lower femoral neck BMD in the postmenopausal women (p = 0.02), and with reduced calcaneal broadband ultrasound attenuation (BUA) values in the whole study population (p = 0.005). There was no association between a TA repeat polymorphism in the ESR1 promoter and any phenotype studied, though on long range haplotype analysis subjects with a smaller number of TA repeats who also carried the px haplotype had reduced BUA values.

Conclusions: The ESR1px haplotype is associated with reduced hip BMD values and increased rates of femoral neck bone loss in postmenopausal women. An association with BUA may explain the fact that ESR1 intron 1 alleles predict osteoporotic fractures by a mechanism partly independent of differences in BMD.

     

Use of restriction fragment length polymorphism as a genetic marker for typing Mycobacterium avium strains.

Restriction fragment length polymorphism (RFLP) was used to study 75 clinical isolates identified as Mycobacterium avium. Two repetitive insertion sequences, IS1311 and IS900, were used as DNA probes. Although less than 25% of isolates showed RFLP patterns with IS900, all strains gave banding patterns with IS1311. M. avium strains isolated from patients with AIDS exhibited marked polymorphism with both probes.     

骨质疏松性椎体压缩骨折椎体成形：漏诊、重度椎体压缩、骨水泥渗漏及再发骨折225例分析

BACKGROUND: Percutaneous vertebroplasty for treatment of osteoporotic vertebral compression fractures has achieved very good results.