Age-specific effects of estrogen receptors' polymorphisms on the bone traits in healthy fertile women: the BONTURNO study

Association between the ESR1 and ESR2 polymorphisms and osteoporosis risk: An updated meta-analysis

BACKGROUND

Gene polymorphisms of estrogen receptor (ESR) 1 PvuII (rs2234693), XbaI (rs9340799), G2014A (rs2228480), ESR2 AluI (rs4986938), and RsaI (rs1256049) had been reported to be associated with the risk of osteoporosis. However, these conclusions were inconsistent, therefore, an updated meta-analysis was conducted to further explore these issues.

OBJECTIVE

To evaluate the association between gene polymorphisms of ESR1 PvuII (rs2234693), XbaI (rs9340799), G2014A (rs2228480), ESR2 AluI (rs4986938), RsaI (rs1256049), and osteoporosis risk.

MATERIALS AND METHODS

PubMed, Medline, Ovid, Embase, CNKI, and China Wanfang databases were searched. Association was assessed using odds ratio with 95% confidence interval. Moreover, the false-positive reporting probability, Bayesian false-finding probability, and Venetian criteria were used to assess the credibility of statistically significant associations.

RESULTS

Overall, ESR1 PvuII (rs2234693) and XbaI (rs9340799) were associated with the risk of osteoporosis in Indians. Moreover, ESR1 G2014A (rs2228480) was associated with the decreased risk of osteoporosis in East Asians. Moreover, ESR2 Alul (rs4986938) was associated with the increased risk of osteoporosis in East Asians and Caucasians. There was a significant association between ESR2 Rsal (rs1256049) and osteoporosis risk in overall population. When only high-quality and Hardy-Weinberg equilibrium studies were included in the sensitivity analysis, all results did not change in the present study. When the credibility was evaluated applying false-positive reporting probability, Bayesian false-finding probability, and Venetian criteria, all significant associations were considered as false positive results.

CONCLUSIONS

In summary, this study shows that all substantial associations between gene polymorphisms of ESR1 (PvuII, XbaI, and G2014A) and ESR 2 (AluI and RsaI) and osteoporosis risk are possibly false positive results instead of real associations or biological variables.

ESR1 polymorphism (rs2234693) influences femoral bone mass in patients with Turner syndrome

Most patients with Turner syndrome (TS) need hormone replacement therapy because of hypergonadotropic hypogonadism; individual outcomes, however, are highly variable. Our objective was to assess the influence of five estrogen receptor 1 gene (ESR1) polymorphisms (rs543650, rs1038304, rs2046210, rs2234693 and rs9340799) on adult height, breast development, uterine volume and bone mineral density (BMD). We studied 91 TS patients from a tertiary hospital using adult estrogen dose. In our group, ESR1 rs2234693 was associated with femoral neck and total hip BMD, and it accounted for around 10% of BMD variability in both sites (P < 0.01). Patients homozygous for C allele in this polymorphism had significantly lower femoral neck BMD (0.699 ± 0.065 g/cm2 vs 0.822 ± 0.113 g/cm2, P = 0.008) and total hip BMD (0.777 ± 0.118 g/cm2 vs 0.903 ± 0.098 g/cm2, P = 0.009) than patients homozygous for T allele. The other four ESR1 polymorphisms were not able to predict any of the above estrogen therapy outcomes in an isolated manner. Patients homozygous for the haplotype GCG formed by polymorphisms rs543650, rs2234693 and rs9340799 had an even more significantly lower femoral neck BMD (0.666 ± 0.049 vs 0.820 ± 0.105 g/cm2, P = 0.0047) and total hip BMD (0.752 ± 0.093 vs 0.908 ± 0.097 g/cm2, P = 0.0029) than patients homozygous for haplotypes with a T allele in rs2234693. In conclusion, homozygosity for C allele in ESR1 rs2234693 and/or for GCG haplotype appears to be associated with lower femoral neck and total hip BMD. We believe that the identification of polymorphisms related to estrogen outcomes may contribute to individualization of treatment in TS.

The rs1256044 polymorphism in the ESR2 gene and the risk for osteoporosis in Polish postmenopausal women

Population association studies have demonstrated a strong association between ESR2 SNPs and BMD, indicating that ESR2 may influence attainment of bone mass. The aim of the study was to investigate the ESR2 gene, located on chromosome 14q linked with BMD, which demonstrates a correlation with changes in bone mass in healthy Caucasian women. The study included 675 unrelated Polish postmenopausal women, including 109 with osteopenia, 333 with osteoporosis and 233 healthy women. The women were classified into the following groups: osteopenia, osteoporosis and normal T-score. Analysis of genotype frequency for the ESR2 rs1256044 polymorphism revealed no statistically significant differences. No statistically significant differences were noted for the allele frequency. However, it is noticeable that the CT genotype occurred more often in women with osteopenia (50.4%, OR = 1.14) and osteoporosis (54.7%, OR = 1.33) than controls (47.7%). There were statistically significant differences between the clinical parameters and distribution of genotypes in patients with osteopenia but not osteoporosis. ESR2 polymorphisms demonstrate minimal influence on BMD changes in women. Identification of various genes with little impact on BMD, such as ESR2, might help design a screening panel for osteoporosis risk assessment in healthy subjects.

The RSPO3 gene as genetic markers for bone mass assessed by quantitative ultrasound in a population of young adults

Ultrasound bone mass measurement has been postulated as a valuable bone-health assessment tool for primary care. The aim of this study was to analyse the possible relationship between the SPTBN1, RSPO3, CCDC170, DKK1, GPATCH1, and TMEM135 genes, with calcaneal quantitative ultrasound (QUS) in a population of young adults. These genes were first associated with broadband ultrasound attenuation (BUA) in the GEFOS/GENOMOS study. A cross-sectional study was conducted on 575 individuals (mean age 20.41 ± 2.69). Bone mass at the right calcaneus was estimated by QUS. Six single-nucleotide polymorphisms (SNPs) in SPTBN1 (rs11898505), RSPO3 (rs7741021), CCDC170 (rs4869739), DKK1 (rs7902708), TMEM135 (rs597319), and GPATCH1 (rs10416265) were selected as genetic markers based on their previous association with calcaneal QUS. After adjusting for multiple confounding factors, the only significant association with QUS in our population was found for the rs7741021 SNP in the RSPO3 gene (P = 0.006) using the dominant model of inheritance. This suggests the possible implication of the RSPO3 gene in bone mass acquisition during early adulthood.

Estrogen receptor α (ESR1) IVS1-397T>C polymorphism lowers risk of fracture

BACKGROUND

Genetic factors are reported to affect fracture incidence. Many groups have explored the correlation of fracture risk with ESR1 IVS1-397T>C. The observed associations, however, are largely inconsistent. This meta-analysis of data from early-released studies was performed in an effort to determine the role of IVS1-397T>C in fracture.

METHODS

Relevant studies were searched through Pubmed, Embase, ScienceDirect, and Wiley Online Library databases. 16 studies meeting all selection criteria were finally identified. We calculated ORs with 95% CIs to assess risk of fracture. Subgroup analyses were performed by subtype, ethnicity and gender.

RESULTS

Data on 2916 cases and 19170 controls were analyzed in the meta-analysis. Overall, we found moderately decreased risk in association with IVS1-397 CC genotype (OR = 0.82, 95% CI = 0.73-0.92; OR = 0.84, 95% CI = 0.76-0.94). The decrease persisted in both hip fracture (OR = 0.82, 95% CI = 0.71-0.94; OR = 0.83, 95% CI = 0.73-0.94) and vertebral fracture (OR = 0.67, 95% CI = 0.50-0.91; OR = 0.78, 95% CI = 0.64-0.97; OR = 0.82, 95% CI = 0.68-0.98) when data were stratified by subtype. We also found a significant trend of decreasing risk in relation to the CC genotype in Caucasian, male and female. All fixed-effects meta-analysis results were homogeneous.

CONCLUSION

The meta-analysis demonstrates that risk of fracture seems likely to be decreased due to IVS1-397 CC or CT genotype.

Association between estrogen receptor α gene (ESR1) PvuII (C/T) and XbaI (A/G) polymorphisms and hip fracture risk: evidence from a meta-analysis

Background and Objective

Genetic factors are important in the pathogenesis of fractures. Notably, estrogen receptor α (ESR1) has been suggested as a possible candidate gene for hip fractures; however, published studies of ESR1 gene polymorphisms have been hampered by small sample sizes and inconclusive or ambiguous results. The aim of this meta-analysis is to investigate the associations between two novel common ESR1 polymorphisms (intron 1 polymorphisms PvuII-rs2234693: C>T and XbaI-rs9340799: A>G) and hip fracture.

Methods

Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the strength of the association.

Results

Five case-control and three cohort studies were assessed, including a total of 1,838 hip fracture cases and 14,972 healthy controls. This meta-analysis revealed that the PvuII T allele is a highly significant risk factor for hip fracture susceptibility, with an effect magnitude similar in male and pre-menopausal and post-menopausal female patients. In stratified analysis based on ethnicity, the PvuII T allele remained significantly correlated with increased risk of hip fracture in Caucasian populations; this correlation, however, was not found in Asian populations. Unlike the PvuII polymorphism, we did not find significant differences in the XbaI (A>G) polymorphism allele or genotype distributions of hip fracture patients and controls. We also found no obvious association between the XbaI polymorphism and hip fracture in any of the racial or gender subgroups.

Conclusion

Our findings show that the ESR1 PvuII T allele may increase the risk of hip fracture and that the XbaI polymorphism is not associated with hip fracture.

Structural maintenance of chromosome complexes and bone development: the beginning of a wonderful relationship?

Bone development depends on environmental, nutritional and hormonal factors. Yet, an ordered and timed activation of genes and their associated molecular pathways are central for the growth and development of healthy bones. The correct expression of genes depends on both cis- and trans-regulatory elements. Of these, the elusive role of chromatin ultrastructure is just beginning to become appreciated. Changes in the higher-order structure of chromatin are affecting the expression of genes in response to intrinsic and environmental signals. Cohesin and condensin are members of the structural maintenance of chromosome (SMC) family of protein complexes, which mediate higher-order chromatin structure by tethering distinct regions of chromatin either inter- or intra-molecularly. In recent years, SMCs had been identified for their function in the regulation of gene expression and developmental processes, whereas malfunction of cohesin or condensin has an impact on human health. However, little is known about the specific roles of SMC complexes in bone development and their possible effect on bone health. Here, we review studies that suggest an intimate link between SMCs and bone development, as well as a plausible effect, direct or indirect, on the bone health. We describe genetic syndromes associated with SMCs with distinctive bone phenotypes and identify links between SMCs and bone-related molecular pathways. Future studies of the relationship between SMCs and bone development will reveal new understandings of both the cellular and molecular roles of SMC complexes and provide new insights into the growth and developmental processes in the bone.

Indications of clinical and genetic predictors for aromatase inhibitors related musculoskeletal adverse events in Chinese Han women with breast cancer

Background

Women with breast cancer treated with aromatase inhibitors (AIs) may experience musculoskeletal symptoms that lead to discontinuation of effective therapy. The purpose of the current study is to evaluate the clinical and genetic predictors for AIs-related musculoskeletal adverse events(MS-AEs).

Methodology and Principal Findings

We recruited 436 postmenopausal Chinese Han women receiving adjuvant AIs therapy for early-stage hormone-sensitive breast cancer. Patients completed a self-administered questionnaire assessing the presence of musculoskeletal symptoms that started or worsened after initiating AIs. 27 single nucleotide polymorphisms (SNP) of ESR1, ESR2 and PGR were analyzed by Sequenom MassARRAY assays and /or PCR-based TaqMan assays.Of the 436 enrolled women, 206 cases experienced musculoskeletal symptoms.Patients who received taxane chemotherapy were more than two times more likely than other patients to have AIs-related MS-AEs. Genetic assay had showed that only two ESR1 SNPs, rs2234693 and rs9340799 were associated with AIs-related MS-AEs.TT genotype and the T allele in rs2234693 was statistically significantly lower in AIs-Related MS-AEs group than controls (P = 0.001; P = 9.49E-7). The frequency of AA genotype and the A allele in rs9340799 was higher (P = 2.20E-5; P = 3.09E-4).

Conclusions and Significance

Our results suggested that prior taxane-based chemotherapy was the clinical predictor, while rs2234693 and rs9340799 were the genetic predictors for AIs-related MS-AEs.

Genetic predictors of skeletal outcomes in healthy fertile women: the Bonturno study

Skeletal traits as height (Ht) or bone mineral density (BMD) are strongly inherited. Low-density lipoprotein receptor-related protein 5 (LRP5) and farnesyl diphosphonate synthase (FDPS) are candidate genes for bone phenotypes. From Bonturno study, we genotyped 570 healthy Caucasian women aged 20 to 50 years (yrs) for LRP5 rs4988321 (A/G) and rs3736228 (C/T) and FDPS rs2297480 (A/C) single nucleotide polymorphisms. Serum C-telopeptide of type I collagen (CTX), osteocalcin (OC), and N-terminal propeptide of type I procollagen (P1NP) were measured in BMD-evaluated subjects at lumbar spine (LS), total hip (TH) and femoral neck (FN) sites. LRP5 rs4988321 locus correlated with FN-BMD (P = 0.0230), while LRP5 rs3736228 genotypes differed in LS-BMD (P = 0.0428). When clustered by age, lower FN-BMD was detected in LRP5 GG (P = 0.030) subjects of 41 to 50 years but not in younger. Both LRP5 GG and CC genotypes showed higher age-adjusted values of OC, CTX and P1NP. Increased CTX values were in LRP5 GGCC subjects than in those having at least one LRP5 A plus T alleles (P = 0.0190). LRP5 CC, GG or GGCC subjects with at least one FDPS C allele showed higher levels of CTX and OC in 31 to 40 yrs or older subjects. In conclusion, LRP5 and FDPS loci age-specifically affect skeletal traits in healthy fertile women.

Susceptibility genes for osteoporotic fracture in postmenopausal Chinese women

To identify the susceptibility genes for osteoporotic fracture in postmenopausal Chinese women, a two-stage case-control association study using joint analysis was conducted in 1046 patients with nontraumatic vertebra, hip, or distal radius fractures and 2303 healthy controls. First, 113 single-nucleotide polymorphisms (SNPs) in 16 potential osteoporosis candidate genes reported in recent genomewide association studies, meta-analyses studies, large-scale association studies, and functional studies were genotyped in a small-sample-size subgroup consisting of 541 patients with osteoporotic fractures and 554 healthy controls. Variants and haplotypes in SPTBN1, TNFRSF11B, CNR2, LRP4, and ESR1 that have been identified as being associated with osteoporotic fractures were further reanalyzed in the entire case-control group. We identified one SNP in TNFRSF11B (rs3102734), three SNPs in ESR1 (rs9397448, rs2234693, and rs1643821), two SNPs in LRP4 (rs17790156 and rs898604), and four SNPs in SPTBN1 (rs2971886, rs2941583, rs2941584, and rs12475342) were associated with all of the broadly defined osteoporotic fractures. The most significant polymorphism was rs3102734, with increased risk of osteoporotic fractures (odds ratio, 1.35; 95% confidence interval [CI], 1.17-1.55, Bonferroni p = 2.6 × 10(-4) ). Furthermore, rs3102734, rs2941584, rs12475342, rs9397448, rs2234693, and rs898604 exhibited significant allelic, genotypic, and/or haplotypic associations with vertebral fractures. SNPs rs12475342, rs9397448, and rs2234693 showed significant genotypic associations with hip fractures, whereas rs3102734, rs2073617, rs1643821, rs12475342, and rs2971886 exhibited significant genotypic and/or haplotypic associations with distal radius fractures. Accordingly, we suggest that in addition to the clinical risk factors, the variants in TNFRSF11B, SPTBN1, ESR1, and LRP4 are susceptibility genetic loci for osteoporotic fracture in postmenopausal Chinese women.

Estrogen receptors α and β have different gender-dependent effects on the adaptive responses to load bearing in cancellous and cortical bone

To determine the effect of estrogen receptors (ER) α and β on bones' adaptive response to loading, we subjected the right tibiae of mice lacking ERα or ERβ activity to either axial loading or to disuse. Adaptive changes in architecture were assessed by comparing differences between the right (treated) and left (control) tibiae in these genotypes as assessed by microcomputed tomography. In female ERα(-/-) mice, the net-osteogenic response to loading was lower in cortical bone compared with their wild-type littermates (11.2 vs. 20.9% in ERα(+/+)), but it was higher in both cortical and cancellous bone of male ERα(-/-) mice (cortical 20.0 vs. 4.6% in ERα(+/+); cancellous 30.0 vs. 5.3% in ERα(+/+), P < 0.05). In ERβ(-/-) male and female mice, the net-osteogenic response to loading was higher in cortical bone (males 10.9 vs. 3.9% in ERβ(+/+); females 18.5 vs. 15.8% in ERβ(+/+), P < 0.05) but no different from controls in cancellous bone. The bone loss in response to disuse was less in cancellous bone of ERα(-/-) mice than in controls (-15.9 vs. -21.3%, respectively, P < 0.05) but no different at any other site or between any other groups. Our conclusion is that functional ERα enhances the net-osteogenic response to loading in cortical but not cancellous bone in female mice but reduces it in males. ERβ decreases the response to loading in cortical bone of males and females but has no effect in cancellous bone. Bone loss due to disuse in cortical bone is unaffected by ER status, but in cancellous bone, functional ERα contributes to greater disuse-related bone loss.

Estrogen receptor-Beta variants are associated with increased risk of Alzheimer's disease in women with down syndrome

BACKGROUND/AIMS

Genetic variants that affect estrogen activity may influence the risk of Alzheimer's disease (AD). We examined the relation of polymorphisms in the gene for the estrogen receptor-beta (ESR2) to the risk of AD in women with Down syndrome.

METHODS

Two hundred and forty-nine women with Down syndrome, 31-70 years of age and nondemented at baseline, were followed at 14- to 18-month intervals for 4 years. Women were genotyped for 13 single-nucleotide polymorphisms (SNPs) in the ESR2 gene, and their association with AD incidence was examined.

RESULTS

Among postmenopausal women, we found a 2-fold increase in the risk of AD for women carrying 1 or 2 copies of the minor allele at 3 SNPs in introns seven (rs17766755) and six (rs4365213 and rs12435857) and 1 SNP in intron eight (rs4986938) of ESR2.

CONCLUSION

These findings support a role for estrogen and its major brain receptors in modulating susceptibility to AD in women.

The ESR2 AluI gene polymorphism is associated with bone mineral density in postmenopausal women

Multiple factors may contribute to the pathogenesis of postmenopausal osteoporosis including environmental, life-style and genetic factors. Common variants in ESR2 gene encoding for ER-beta, highly expressed in bone tissue, have recently been proposed as candidates for affecting bone phenotype at the population level, particularly in postmenopausal women. In this study, we examined the genetic background at ESR2 AluI (rs4986938, 1730G>A) locus in 89 osteopenic, postmenopausal women (age range 49-56 years) together with BMD at lumbar spine and femoral neck sites as well as variations in plasma levels of bone metabolism and turnover markers. Genotyping for ESR2 G1730A polymorphism showed that the frequency of A mutated allele accounted for 0.4 in our cohort of postmenopausal women; moreover, the GA1730 heterozygous individuals were the most represented (50.6%) compared with GG (37.8%) and AA homozygous ones (14.6%). A regression analysis showed that lumbar spine BMD values were significantly associated with both ESR2 AA1730 genotype (p=0.044) and time since the onset of menopause (p=0.031), while no significant association was detected between biochemical markers and genetic background. Interestingly, 85% of patients with AA1730 genotype presented the smallest lumbar spine BMD values. These findings first indicate a worsening effect of ESR2 AluI polymorphism on lumbar spine BMD reduction in postmenopause, suggesting that the detection of this ESR2 variant should be recommended in postmenopausal women, particularly in populations with a high prevalence of ESR2 AA1730 homozygous genotype.

Pharmacogenetics of osteoporosis-related bone fractures: moving towards the harmonization and validation of polymorphism diagnostic tools

Osteoporosis is one of the most common skeletal chronic conditions in developed countries, hip fracture being one of its major healthcare outcomes. There is considerable variation in the implementation of current pharmacological treatment and prevention, despite consistent recommendations and guidelines. Many studies have reported conflicting findings of genetic associations with bone density and turnover that might predict fracture risk. Moreover, it is not clear whether genetic differences exist in relation to the morbidity and efficiency of the pharmacotherapy treatments. Clinical response, including beneficial and adverse events associated with osteoporosis treatments, is highly variable among individuals. In this context, the present article intends to summarize putative candidate genes and genome-wide association studies that have been related with BMD and fracture risk, and to draw the attention to the need for pharmacogenetic methodology that could be applicable in clinical translational research after an adequate validation process. This article mainly compiles analysis of important polymorphisms in osteoporosis documented previously, and it describes the simple molecular biology tools for routine genotype acquisition. Validation of methods for the easy, fast and accessible identification of SNPs is necessary for evolving pharmacogenetic diagnostic tools in order to contribute to the discovery of clinically relevant genetic variation with an impact on osteoporosis and its personalized treatment.

Genotypes and haplotypes of the estrogen receptor genes, but not the retinoblastoma-interacting zinc finger protein 1 gene, are associated with osteoporosis

Osteoporosis is a common age-related disease with a strong genetic influence. Polymorphisms of ESR1 have consistently been shown to be associated with bone mineral density (BMD) and fracture; however, in regulating bone metabolism, ESR1 interacts with both ESR2 and RIZ1. We therefore examined the effects of polymorphisms in the ESR1, ESR2, and RIZ1 genes and their haplotypes on vertebral fractures and BMD in a case-control study comprising 462 osteoporotic patients and 336 controls. In ESR1, we found the variant C allele of the XbaI polymorphism to be associated with decreased risk of vertebral fractures in women (P < 0.01), whereas in men, the T allele seemed protective (P = 0.05). The variant G allele of the PvuII polymorphism decreased the risk of vertebral fractures independently of lumbar spine BMD in women (P = 0.04) but had no effect in men. Haplotype X-P-H (XbaI:C, PvuII:G, and a high number of TA repeats) was associated with decreased risk of vertebral fractures in women (P = 0.04) but not men. In ESR2, the G allele of the AluI polymorphism was associated with increased fracture risk (P = 0.04), and the haplotype that comprises rs1256031:T and AluI:A increased lumbar spine BMD by 0.04 +/- 0.02 g/cm(2) (P < 0.05) and decreased the risk of vertebral fractures (P = 0.04). There was no effect of the RIZ1 polymorphism on BMD or fracture risk and no evidence of interaction between the polymorphisms and haplotypes thereof. We confirm that genetic variants in ESR1 and ESR2, but not RIZ1, are important in osteoporosis. We found no evidence of interaction between polymorphisms, but we found that the effects of genetic variants in ESR1 might be sex dependent.

Genetics of osteoporosis: accelerating pace in gene identification and validation

Osteoporosis is characterized by low bone mineral density and structural deterioration of bone tissue, leading to an increased risk of fractures. It is the most common metabolic bone disorder worldwide, affecting one in three women and one in eight men over the age of 50. In the past 15 years, a large number of genes have been reported as being associated with osteoporosis. However, only in the past 4 years we have witnessed an accelerated pace in identifying and validating osteoporosis susceptibility loci. This increase in pace is mostly due to large-scale association studies, meta-analyses, and genome-wide association studies of both single nucleotide polymorphisms and copy number variations. A comprehensive review of these developments revealed that, to date, at least 15 genes (VDR, ESR1, ESR2, LRP5, LRP4, SOST, GRP177, OPG, RANK, RANKL, COLIA1, SPP1, ITGA1, SP7, and SOX6) can be reasonably assigned as confirmed osteoporosis susceptibility genes, whereas, another >30 genes are promising candidate genes. Notably, confirmed and promising genes are clustered in three biological pathways, the estrogen endocrine pathway, the Wnt/beta-catenin signaling pathway, and the RANKL/RANK/OPG pathway. New biological pathways will certainly emerge when more osteoporosis genes are identified and validated. These genetic findings may provide new routes toward improved therapeutic and preventive interventions of this complex disease.