Pharmacogenetics of follicle-stimulating hormone action

Genetic screening of PLA1/PLA2 polymorphous marker of integrin beta 3 (ITGB3) GP IIIA gene in adolescent girls with puberty menorrhagia

Puberty menorrhagia is one of the urgent problems of modern reproductive medicine. The study aimed to investigate the relationship between polymorphism of the GP IIIa (PLA1/PLA2) gene and improve the diagnosis of puberty menorrhagia in girls with thyroid gland pathology. Ninety-seven girls at puberty age were divided into three groups: group 1 (main) - girls with puberty menorrhagia and thyroid gland pathology (30 individuals), group 2 (comparison) - 40 girls with puberty menorrhagia, group 3 (control) - 27 practically healthy girls. Polymorphism of the GP IIIa (PLA1/PLA2) gene was studied by isolating genomic DNA from peripheral blood leukocytes, followed by amplification with a polymerase chain reaction. Results showed that mutation in the 17^th chromosome of q21.32 of the GP IIIa gene occurred in 8.6% of cases among adolescents with menorrhagia, in contrast to the control group, where it was not observed at all. The A1A1-genotype occurred by 11.7% (X²=4.01, p=0.041) more often in adolescents with menorrhagia than in girls with concomitant thyroid gland pathology and by 15.0% (X²=4.54, p=0.033) more often than in the control group. It was also found that the presence of the A1A2-genotype unreliably reduced the chances of uterine bleeding in adolescent girls by 1.45 times (OR=2.12) and was a protective factor in the puberty menorrhagia occurrence (OR=0.47). It may be concluded that the identification of a hereditary factor of the reproductive system diseases of adolescent girls fundamentally changes the point of view on the tactics of disease management and subsequent therapy.

LH increases the response to FSH in granulosa-lutein cells from sub/poor-responder patients in vitro

STUDY QUESTION

Does LH addition to FSH in vitro recover the human primary granulosa lutein cell (hGLC) sub/poor-response?

SUMMARY ANSWER

A picomolar concentration of LH may recover the FSH-induced cAMP and progesterone production of hGLC from sub/poor-responder women.

WHAT IS KNOWN ALREADY

Clinical studies suggested that FSH and LH co-treatment may be beneficial for the ovarian response of sub/poor-responders undergoing ovarian stimulation during ART.

STUDY DESIGN, SIZE, DURATION

hGLC samples from 286 anonymous women undergoing oocyte retrieval for ART were collected from October 2017 to February 2021.

PARTICIPANTS/MATERIALS, SETTING, METHODS

hGLCs from women undergoing ovarian stimulation during ART were blindly purified, cultured, genotyped and treated in vitro by increasing concentrations of FSH (nM) ±0.5 nM LH. cAMP and progesterone levels produced after 3 and 24 h, respectively, were measured. In vitro data were stratified a posteriori, according to the donors' ovarian response, into normo-, sub- and poor-responder groups and statistically compared. The effects of LH addition to FSH were compared with those obtained by FSH alone in all the groups as well.

MAIN RESULTS AND THE ROLE OF CHANCE

hGLCs from normo-responders were shown to have higher sensitivity to FSH treatment than sub-/poor-responders in vitro. Equimolar FSH concentrations induced higher cAMP (about 2.5- to 4.2-fold), and progesterone plateau levels (1.2- to 2.1-fold), in cells from normo-responder women than those from sub-/poor-responders (ANOVA; P < 0.05). The addition of LH to the cell treatment significantly increased overall FSH efficacy, indicated by cAMP and progesterone levels, within all groups (P > 0.05). Interestingly, these in vitro endpoints, collected from the normo-responder group treated with FSH alone, were similar to those obtained in the sub-/poor-responder group under FSH + LH treatment. No different allele frequencies and FSH receptor (FSHR) gene expression levels between groups were found, excluding genetics of gonadotropin and their receptors as a factor linked to the normo-, sub- and poor-response. In conclusion, FSH elicits phenotype-specific ovarian lutein cell response. Most importantly, LH addition may fill the gap between cAMP and steroid production patterns between normo- and sub/poor-responders.

LIMITATIONS, REASONS FOR CAUTION

Although the number of experimental replicates is overall high for an in vitro study, clinical trials are required to demonstrate if the endpoints evaluated herein reflect parameters of successful ART. hGLC retrieved after ovarian stimulation may not fully reproduce the response to hormones of granulosa cells from the antral follicular stage.

WIDER IMPLICATIONS OF THE FINDINGS

This in vitro assay may describe the individual response to personalize ART stimulation protocol, according to the normo-, sub- and poor-responder status. Moreover, this in vitro study supports the need to conduct optimally designed, randomized clinical trials exploring the personalized use of LH in assisted reproduction.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by Merck KGaA. M.L. and C.C. are employees of Merck KGaA or of the affiliate Merck Serono SpA. Other authors have no competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

A GWAS in Idiopathic/Unexplained Infertile Men Detects a Genomic Region Determining Follicle-Stimulating Hormone Levels

CONTEXT

Approximately 70% of infertile men are diagnosed with idiopathic (abnormal semen parameters) or unexplained (normozoospermia) infertility, with the common feature of lacking etiologic factors. Follicle-stimulating hormone (FSH) is essential for initiation and maintenance of spermatogenesis. Certain single-nucleotide variations (SNVs; formerly single-nucleotide polymorphisms [SNPs]) (ie, FSHB c.-211G > T, FSHR c.2039A > G) are associated with FSH, testicular volume, and spermatogenesis. It is unknown to what extent other variants are associated with FSH levels and therewith resemble causative factors for infertility.

OBJECTIVE

We aimed to identify further genetic determinants modulating FSH levels in a cohort of men presenting with idiopathic or unexplained infertility.

METHODS

We retrospectively (2010-2018) selected 1900 men with idiopathic/unexplained infertility. In the discovery study (n = 760), a genome-wide association study (GWAS) was performed (Infinium PsychArrays) in association with FSH values (Illumina GenomeStudio, v2.0). Minor allele frequencies (MAFs) were analyzed for the discovery and an independent normozoospermic cohort. In the validation study (n = 1140), TaqMan SNV polymerase chain reaction was conducted for rs11031005 and rs10835638 in association with andrological parameters.

RESULTS

Imputation revealed 9 SNVs in high linkage disequilibrium, with genome-wide significance (P < 4.28e-07) at the FSHB locus 11p.14.1 being associated with FSH. The 9 SNVs accounted for up to a 4.65% variance in FSH level. In the oligozoospermic subgroup, this was increased up to 6.95% and the MAF was enhanced compared to an independent cohort of normozoospermic men. By validation, a significant association for rs11031005/rs10835638 with FSH (P = 4.71e-06/5.55e-07) and FSH/luteinizing hormone ratio (P = 2.08e-12/6.4e-12) was evident.

CONCLUSIONS

This GWAS delineates the polymorphic FSHB genomic region as the main determinant of FSH levels in men with unexplained or idiopathic infertility. Given the essential role of FSH, molecular detection of one of the identified SNVs that causes lowered FSH and therewith decreases spermatogenesis could resolve the idiopathic/unexplained origin by this etiologic factor.

Sequencing Reveals Population Structure and Selection Signatures for Reproductive Traits in Yunnan Semi-Fine Wool Sheep (Ovis aries)

Yunnan semi-fine wool sheep are among the most important cultivated sheep breeds in China. However, their population structure, genetic characteristics and traits of interest are poorly studied. In this study, we systematically studied the population characteristics and selection signatures of 40 Yunnan semi-fine wool sheep using SNPs obtained from whole-genome resequencing data. A total of 1393 Gb of clean data were acquired. The mapping rate against the reference genome was 91.23% on average (86.01%–92.26%), and the average sequence depth was 9.51X. After filtering, 28,593,198 SNPs and 4,725,259 indels with high quality were obtained. The heterozygosity rate, inbreeding coefficient and effective population size of the sheep were calculated to preliminarily explore their genetic characteristics. The average heterozygosity rate was 0.264, the average inbreeding coefficient was 0.0099, and the effective population size estimated from the heterozygote excess (HE) was 242.9. Based on the Tajima’s D and integrated haplotype score (iHS) approaches, 562 windows and 11,356 core SNPs showed selection signatures in the Yunnan semi-fine wool sheep population. After genome annotation and gene enrichment analysis, we found traces of early domestication in sensory organs, behavioural activity and the nervous system as well as adaptive changes in reproductive and wool traits under selection in this population. Some selected genes related to litter size, including FSHR, BMPR1B and OXT, were identified as being under selection. Specific missense mutations of the FSHR gene that differed from the reference genome were also identified in the population, and we found some SNP variations that may affect litter size. Our findings provide a theoretical basis for the conservation and utilization of Yunnan semi-fine wool sheep. Furthermore, our results reveal some changes common to sheep after domestication and provide a new opportunity to investigate the genetic variation influencing fecundity within a population evolving under artificial selection.

Does Follicle-Stimulating hormone receptor polymorphism status affect In vitro fertilization-intracytoplasmic sperm injection results and live birth rate? A retrospective study

Background:

Follicle-stimulating hormone (FSH) plays a key role in fertility and shows its effect through the FSH receptor (FSHR), which is localized in cells.

Aims:

The aim of this study was to examine pregnancy outcomes and responses to controlled ovarian stimulation according to FSHR polymorphism types.

Study Setting and Design:

The study was retrospective, and included patients who applied to the University of Health Sciences Tepecik Training and Research Hospital in vitro fertilization (IVF) Unit during 2018 and 2019.

Materials and Methods:

Patients who underwent IVF-intracytoplasmic sperm injection and at the same time studied FSHR gene polymorphism in the genetic unit of our hospital were included in the study.

Statistical Analysis:

The Kruskal–Wallis test was used for multiple comparisons of continuous variables. The Chi-square test was used for categorical variables between groups.

Results:

A total of 143 patients who met our criteria were included in the study. 14% (n = 20) of the patients are also homozygous natural (Asn/Asn) type; 44.7% (n = 64) of the heterozygous mutant (Asn/Ser) type; 41.3% (n = 59) of them were homozygous mutant (Ser/Ser) type. There was no statistically significant difference between the groups in terms of pregnancy rate per started cycle, ongoing pregnancy per started cycle, ongoing pregnancy per embryo transfer and live birth per embryo transfer. A significant difference was observed between peak E2 and peak progesterone levels between Asn/Ser and Ser/Ser groups, and the levels of these hormones were lower in the Ser/Ser group (P = 0.018 and P = 0.016, respectively). Ovarian responses were classified as poor (≤3 oocytes), normal (4-20 oocytes) and hyperresponse (≥20 oocytes) according to the oocyte count. Accordingly, the number of patients with poor response was higher in the Ser/Ser group (P = 0.011).

Conclusions:

Ser/Ser polymorphism is characterised by a poor ovarian response. Despite this, polymorphisms in the FSHR gene do not seem to affect the results of pregnancy per started cycle, ongoing pregnancy per started cycle, ongoing pregnancy per embryo transfer and live birth per embryo transfer.

Variants Ala307Ala and Ser680Ser of 307 and 680 FSHr polymorphisms negatively influence on assisted reproductive techniques outcome and determine high probability of non-pregnancy in Caucasian patients

PURPOSE

To determine the influence of different genotypes of Ala307Thr and Asn680Ser FSHr polymorphisms on controlled ovarian stimulation (COS) outcome and pregnancy.

METHODS

This study collected blood and physiological and clinical parameters of 517 Caucasian patients (Statistical power ≥ 80%) that underwent COS treatment. Genotypes of Ala307Thr and Asn680Ser polymorphisms were determined using PCR amplification followed by Bsu36I and BsrI digestion, respectively.

RESULTS

Ala307Ala and Ser680Ser genotypes associated to worse parameters of COS outcome (preovulatory follicles P = 0.05, in both), justifying their lower pregnancy rate than Non-Ala307Ala, P = 0.01 and Non-Ser680Ser, P = 0.004, respectively or together, (P = 0.003). Within the Non-Ala307Ala group, Thr307Thr genotype showed higher number of fertilized oocytes (P = 0.04) and embryos (P = 0.01) than Non-Thr307Thr, but no influence on pregnancy rate. Ala307Ala and Ser680Ser patients doubled probability of non-pregnancy than Non-Ala307Ala (odds ratio = 2.0) and Non-Ser680Ser (odds ratio = 2.11), respectively. Ala307Ala and Ser680Ser genotypes tend to appear together (P < 0.0001), which increases the probability of non-pregnancy.

CONCLUSIONS

Ala307Ala and Ser680Ser genotypes of 307 and 680 FSHr polymorphisms associate to worse COS outcome than its respective Non-Ala307Ala and Non-Ser680Ser. Within the Non-Ala307Ala genotypes, Thr307Thr, although shows higher Fertilized Oocytes and Embryos, do not influence on pregnancy rate. Ala307Ala and Ser680Ser genotypes double the probability of Non-Pregnancy than their respective Non-Ala307Ala and Non-Ser680Ser genotypes. Furthermore, the strong tendency of these genotypes to appear together worsens the probability of pregnancy in these patients.

The Role of FSHR SNPs and AMH in Follicular Fluid and Serum in Ovarian Response during COS: A Pilot Study

Background

Several studies have investigated on the polymorphism Ser680Asn of FSHR and its use as a predictive indicator of response to an IVF/ICSI protocol. Furthermore, measurement of AMH in serum and follicular fluid is a useful prognostic indicator for the outcome of an assisted reproduction attempt. The purpose of this study is to examine the FSH receptor Ser680Asn polymorphism in combination with AMH levels in both serum and follicular fluid, on the day of oocyte collection.

Materials and Methods

A total of 32 women who underwent IVF/ICSI were included. Women were grouped into 2 groups: those who received rFSH (n = 11) and those who received hMG (n = 21). Serum AMH was measured on day 3 of the cycle, and AMH in the follicular fluid on the day of oocyte retrieval; the same day peripheral blood was collected for the genotyping of Ser680Asn.

Results

No statistical significant difference was found between serum AMH and follicular fluid AMH regarding the FSH receptor genotype for the Ser680Asn polymorphism. Regarding the sAMH/ffAMH ratio in the 3 genotypes, the value was lower in Asn/Asn women than Ser/Ser and Ser/Asn, but no statistical difference was obtained. Women who carry the Ser allele have a higher number of follicles, retrieved oocytes, and mature oocytes than women who do not contain the Ser allele. Women with AMH < 2.22 ng/ml presented lower AMH follicular fluid levels and lower serum AMH/follicular fluid AMH ratio in a statistically significant manner. Concerning the genotype for the polymorphism Ser680Asn of FSHR in relation to AMH levels, no statistically significant differences were found.

Conclusions

The identification of polymorphisms, such as Ser680Asn of FSHR, along with the determination of endocrine markers in the follicular fluid, such as AMH, could lead at some point, to the personalized therapy setting per woman.

Does the FSHB c.-211G>T polymorphism impact Sertoli cell number and the spermatogenic potential in infertile patients?

BACKGROUND

A genetic variant within the FSHB gene can deviate FSH action on spermatogenesis. The c.-211G>T FSHB single nucleotide polymorphism impacts FSHB transcription and biosynthesis due to interference with the LHX3 transcription factor binding. This SNP was previously shown to be strongly associated with lowered testicular volume, reduced sperm counts, and decreased FSH levels in patients carrying one or two T-alleles.

OBJECTIVE

To determine the impact of the SNP FSHB c.-211G>T on Sertoli cell (SC) number, Sertoli cell workload (SCWL) and thereby spermatogenic potential.

MATERIAL AND METHODS

Testicular biopsies of 31 azoospermic, homozygous T patients (26 non-obstructive azoospermia (NOA), and five obstructive azoospermia (OA)) were matched to patients with GG genotype. Marker proteins for SC (SOX9), spermatogonia (MAGE A4), and round spermatids (CREM) were used for semi-automatical quantification by immunofluorescence. SCWL (number of germ cells served by one SC) was determined and an unbiased clustering on the patient groups performed.

RESULTS

Quantification of SC number in NOA patients did not yield significant differences when stratified by FSHB genotype. SC numbers are also not significantly different between FSHB genotypes for the OA patient group and between NOA and OA groups. SCWL in the NOA patient cohort is significantly reduced when compared to the OA control patients; however, in neither group an effect of the genotype could be observed. The cluster analysis of the whole study cohort yielded two groups only, namely NOA and OA, and no clustering according to the FSHB genotype.

DISCUSSION AND CONCLUSION

The FSHB c.-211G>T polymorphism does not affect SC numbers or SCWL, thereby in principle maintaining the spermatogenic potential. The previously observed clinical phenotype for the FSHB genotype might therefore be caused by a hypo-stimulated spermatogenesis and not due to a decreased SC number.

Genetics of male infertility

Male infertility is a multifactorial pathological condition affecting approximately 7% of the male population. The genetic landscape of male infertility is highly complex as semen and testis histological phenotypes are extremely heterogeneous, and at least 2,000 genes are involved in spermatogenesis. The highest frequency of known genetic factors contributing to male infertility (25%) is in azoospermia, but the number of identified genetic anomalies in other semen and aetiological categories is constantly growing. Genetic screening is relevant for its diagnostic value, clinical decision making, and appropriate genetic counselling. Anomalies in sex chromosomes have major roles in severe spermatogenic impairment. Autosome-linked gene mutations are mainly involved in central hypogonadism, monomorphic teratozoospermia or asthenozoospermia, congenital obstructive azoospermia, and familial cases of quantitative spermatogenic disturbances. Results from whole-genome association studies suggest a marginal role for common variants as causative factors; however, some of these variants can be important for pharmacogenetic purposes. Results of studies on copy number variations (CNVs) demonstrate a considerably higher CNV load in infertile patients than in normozoospermic men, whereas whole-exome analysis has proved to be a highly successful diagnostic tool in familial cases of male infertility. Despite such efforts, the aetiology of infertility remains unknown in about 40% of patients, and the discovery of novel genetic factors in idiopathic infertility is a major challenge for the field of androgenetics. Large, international, and consortium-based whole-exome and whole-genome studies are the most promising approach for the discovery of the missing genetic aetiology of idiopathic male infertility.

Development of a robust reporter gene-based assay for the bioactivity determination of recombinant human follicle stimulating hormone (rhFSH) pharmaceutical products

FSH plays a key role in the function of the reproductive system of human beings and is widely used both diagnostically and therapeutically in reproductive medicine. With the growing incidence of infertility, the demand for FSH pharmaceutical products is increasing. For this reason, the quality control process for FSH products is becoming more stringent. An accurate determination of bioactivity is crucial for the safety and efficacy of recombinant human follicle stimulating hormone (rhFSH). Up to now, in-vivo bioassay based on FSH-induced increases in rat ovarian weight has been the only method widely accepted by different pharmacopoeias. However this method has such drawbacks as the complex procedures, long assay period and high variability. Here, we established a reporter gene assay (RGA) based on the CHO-K1-FSHR-CRE-Luc cell line that stably expresses human follicle stimulating hormone receptor (hFSHR), as well as a luciferase reporter under the control of cyclic adenosine monophosphate (cAMP) response elements (CRES). Our study showed that our new assay not only has good dose-dependent responsiveness to rhFSH, but it also performs excellently in terms of specificity, precision, linearity, and simplicity compared with in-vivo rat bioassays. These results implied that this robust reporter gene assay may be a viable supplement to the animal in-vivo bioassay and may be employed in potency determination of rhFSH pharmaceutical products.

FSHB -211 G>T is a major genetic modulator of reproductive physiology and health in childbearing age women

STUDY QUESTION

Are the genetic variants FSHB -211 G>T (rs10835638), FSHR c.2039 A>G (Asn680Ser, rs6166) and FSHR -29 G>A (rs1394205) associated with serum FSH, LH and anti-Müllerian hormone (AMH) levels in reproductive age women, their menstrual cycle parameters and risk of infertility?

SUMMARY ANSWER

Only the FSHB -211 G>T variant was a major genetic determinant of serum gonadotropin levels in both, eumenorrheic healthy women and female infertility patients, and the T-allele carrier status was enriched among idiopathic infertility cases.

WHAT IS KNOWN ALREADY

There are accumulating data on common genetic variants modulating reproductive parameters and fertility potential. FSHB -211 G>T represents the strongest acknowledged genetic factor contributing to male circulating gonadotropins levels. Respective data in women are limited and the two previously published studies have reached conflicting results. In addition, previous studies have consistently associated FSHR c.2039 A>G (but not FSHR -29 G>A) with female serum FSH level.

STUDY DESIGN, SIZE, DURATION

The study aimed to test robust and clinically meaningful genetic effects (if present) of the FSHB -211 G>T, FSHR c.2039 A>G and FSHR -29 G>A variants on female basal FSH, LH and AMH levels, and linked reproductive parameters. Genetic association testing was performed in two independent and clinically different study groups (i) eumenorrheic healthy women without known fertility problems (n = 169; 27.6 ± 6.1 years) and (ii) female partners of infertile couples (n = 186; 32.4 ± 4.7 years). The study groups were compared for allelic and genotypic distributions of the analysed variants.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All participants were recruited during the HAPPY PREGNANCY study (2013-2015) at the Women's Clinic, Tartu University Hospital, Estonia. Serum FSH, LH and AMH were measured in the follicular phase (Days 2-6) of the menstrual cycle. All three single nucleotide polymorphisms (SNPs) were genotyped by PCR and Taqman allelic discrimination assay. The effect of the analysed variants on hormonal measurements and menstrual cycle data was assessed using linear regression under additive and recessive models adjusted by age, BMI and smoking status. Results of the two subgroups were combined in a meta-analysis applying the fixed effects model. Restricted maximum likelihood analysis was applied to estimate the proportion of total phenotypic variance of analysed reproductive parameters, explainable by the tested genetic variants. In case-control analysis, genetic association with infertility status was tested using Fisher's exact test and logistic regression adjusted by age, BMI and smoking status.

MAIN RESULTS AND THE ROLE OF CHANCE

In both study groups, T-allele of the FSHB -211 G>T was associated with significantly higher serum levels of FSH and LH. Results of the meta-analysis (additive genetic model) remained significant after Bonferroni correction for multiple testing: FSH, T-allele effect 0.80 IU/L, P = 1.2 × 10-3; LH, 1.58 IU/L, P = 1.8×10-8. A more pronounced effect of T-allele of the FSHB -211 G>T on circulating LH was identified as a driving factor to increased LH/FSH ratio (meta-analysis, P = 4.7 × 10-3). In healthy women, the FSHB -211 G>T variant was estimated to explain 3.5 and 7.1% of the total variance of the measured serum FSH and LH levels, respectively. The corresponding numbers for the infertility patients were 1.6 and 10.5%. Women with idiopathic infertility compared to controls exhibited a doubled T-allele frequency (23.6 versus 12.4%; P = 8.9 × 10-3) and a >3-fold excess of TT homozygotes (5.6 versus 1.8%; P = 3.5 × 10-2). The only association of the FSHR c.2039 A>G was detected with serum FSH levels in eumenorrheic healthy women, explaining 3.9% of the total parameter variance (G-allele effect 0.56 IU/L, P = 4.6 × 10-3). In the study group of healthy reproductive age women, the highest serum FSH levels were detected among the FSHB -211 T-allele carriers with the FSHR c.2039 GG-genotype (median 7.7 IU/L). In contrast, the lowest hormone concentrations were measured for the women carrying the combination of the FSHB -211 GG- and the FSHR c.2039 AA-homozygosity (median 5.8 IU/L, P = 9.6 × 10-3). None of the analysed reproductive parameters was associated with the FSHR -29 G>A variant. In our study groups, the tested polymorphisms did not reach significant associations with serum AMH measurements, menstrual cycle length or age at menarche.

LIMITATIONS, REASONS FOR CAUTION

Small sample size and the design involving two clinical groups with different reproductive histories may have limited the capacity to replicate the associations with the age at menarche and length of menstrual cycle, initially reported in large genome-wide association studies. Small sample size may have also affected the accuracy in estimating the contribution of the tested variants to the total phenotypic variance of measured gonadotropin concentrations. The group of eumenorrheic healthy women had its limitations as a control to estimate the true effect of analysed genetic variants on individual's fertility potential as the recruitment strategy had been targeted mostly towards younger women, who may not yet have planned to conceive a child by this age.

WIDER IMPLICATIONS OF THE FINDINGS

We propose that like in men, also in women the FSHB -211 G>T represents a key genetic modulator of circulating gonadotropin, leading to various possible downstream effects on reproductive physiology. This claim is strongly supported by the reports of genome-wide association studies on various female reproductive traits and diseases. In perspective, FSHB -211 G>T may have a diagnostic value in fertility clinics to detect female patients with genetically inherited elevated basal FSH and LH levels.

STUDY FUNDING/COMPETING INTEREST(S)

The study was supported by Estonian Science Foundation Grant (ETF9030 for M.L.); Institutional Research Grant (IUT34-12 for M.L.) and European Union through the European Regional Development Fund (project HAPPY PREGNANCY, 3.2.0701.12-0047; for M.L. and K.R.). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the article. We have no competing interests to declare.

TRAIL REGISTRATION NUMBER

Not applicable.

Pharmacogenetics of FSH Action in the Male

Male infertility is a major contributor to couple infertility, however in most cases it remains "idiopathic" and putative treatment regimens are lacking. This leads to a scenario in which intra-cytoplasmic spermatozoa injection (ICSI) is widely used in idiopathic male infertility, though the treatment burden is high for the couple and it entails considerable costs and risks. Given the crucial role of the Follicle-stimulating hormone (FSH) for spermatogenesis, FSH has been used empirically to improve semen parameters, but the response to FSH varied strongly among treated infertile men. Single nucleotide polymorphisms (SNPs) within FSH ligand/receptor genes (FSHB/FSHR), significantly influencing reproductive parameters in men, represent promising candidates to serve as pharmacogenetic markers to improve prediction of response to FSH. Consequently, several FSH-based pharmacogenetic studies have been conducted within the last years with unfortunately wide divergence concerning selection criteria, treatment and primary endpoints. In this review we therefore outline the current knowledge on single nucleotide polymorphisms (SNPs) in the FSH and FSH receptor genes and their putative functional effects. We compile and critically assess the previously performed pharmacogenetic studies in the male and propose a putative strategy that might allow identifying patients who could benefit from FSH treatment.

Frequency of the T307A, N680S, and -29G>A single-nucleotide polymorphisms in the follicle-stimulating hormone receptor in Mexican subjects of Hispanic ancestry

BACKGROUND

FSHR SNPs may influence the ovarian sensitivity to endogenous and exogenous FSH stimulation. Given the paucity of data on the FSHR c.919A > G, c.2039A > G and - 29G > A SNPs in Hispanic population, we here analyzed their frequency distribution in Mexican mestizo women.

METHODS

Samples from 224 Mexican mestizo women enrolled in an IVF program as well as a genotype database from 8182 Mexican mestizo subjects, were analyzed for FSHR SNPs at positions c.919, c.2039 and - 29G > A. Association between the genetic variants and reproductive outcomes was assessed.

RESULTS

The c.919 and c.2039 SNPs were in strong linkage disequilibrium and their corresponding genotype frequencies in the IVF group were: AA 46.8%, AG 44.2%, and GG 8.9%, and AA 41.9%, AG 48.2% and GG 9.8%, respectively. For the -29G > A SNP, genotype frequencies were 27% (GG), 50% (GA) and 23% (AA). In normal oocyte donors with the c.2039 GG genotype, the number of oocytes recovered after ovarian stimulation (COS) were significantly (p < 0.01) lower than in those bearing other genotypes in this or the -29G > A SNP. Analysis of the large scale database revealed that both allelic and genotype frequencies for the three SNPs were very similar to those detected in the IVF cohort (p ≥ 0.38) and that female carriers of the c.2039 G allele tended to present lower number of pregnancies than women bearing the AA genotype; this trend was stronger when women with more Native American ancestry was separately analyzed (OR = 2.0, C.I. 95% 1.03-3.90, p = 0.04). There were no differences or trends in the number of pregnancies among the different genotypes of the -29G > A SNP.

CONCLUSIONS

The frequency of the GG/GG combination genotype for the c.919 and c.2039 SNPs in Mexican hispanics is among the lowest reported. The GG genotype is associated with decreased number of oocytes recovered in response to COS as well as to lower pregnancy rates in Hispanic women from the general population. The absence of any effect of the -29AA genotype on the response to COS, indicates that there is no need to perform this particular genotype testing in Hispanic women with the purpose of providing an individually-tailored COS protocol.

Role of FSHR rs6165 and ESR2 rs4986938 polymorphisms in ovarian stimulation of Iranian women who underwent assisted reproduction treatment

BACKGROUND

Gonadotropin therapy was used to stimulate the ovary in infertile women who underwent assisted reproduction treatment (ART). Numerous studies indicated that infertile women showed different responses to gonadotropin therapy. Follicle stimulating hormone receptor (FSHR) and Oestrogen receptor (ER) polymorphisms have been reported to involve induction of folliculogenesis and ovarian response to treatment.

METHODS

In the present study, two polymorphisms, namely FSHR rs6165 and ESR2 rs4986938, were investigated in 198 Iranian infertile women aged less than 39 years who underwent ART. After DNA extraction, these polymorphisms were genotyped by TaqMan genotyping assay. According to the number of eggs released during ovulation, the patients were categorized into poor responders (PR) and good responders (GR). The results indicated that the good responders showed lower levels of FSH and LH than poor responders.

RESULTS

No association was observed between ESR2 rs4986938 and poor response in Iranian women patients. Instead, FSHR rs6165 showed a strong association with ovarian response to ART (p< 0.05).

CONCLUSION

The obtained results indicated that FSHR rs6165, not ESR2 rs4986938, could be suggested as a candidate marker to predict poor ovarian response.

Extragonadal Effects of Follicle-Stimulating Hormone on Osteoporosis and Cardiovascular Disease in Women during Menopausal Transition

The risk of osteoporosis and cardiovascular disease increases significantly in postmenopausal women. Until recently, the underlying mechanisms have been primarily attributed to estrogen decline following menopause. However, follicle-stimulating hormone (FSH) levels rise sharply during menopausal transition and are maintained at elevated levels for many years. FSH receptor has been detected in various extragonadal sites, including osteoclasts and endothelial cells. Recent advances suggest FSH may contribute to postmenopausal osteoporosis and cardiovascular disease. Here, we review the key actions through which FSH contributes to the risk of osteoporosis and cardiovascular disease in women as they transition through menopause. Advancing our understanding of the precise mechanisms through which FSH promotes osteoporosis and cardiovascular disease may provide new opportunities for improving health-span for postmenopausal women.

The impact of FSH receptor polymorphism on time-to-pregnancy: a cross-sectional single-centre study

Background

Single nucleotide polymorphism of the follicle-stimulating hormone (FSH) receptor (FSHR) is an important marker of ovarian function. However, its role in female fecundity remains debatable. The aim of the study to assess the relationship of FSHR polymorphism of Serine/Serine, Asparagine/Asparagine and Asparagine/Serine variants directly against the time-to-pregnancy (TTP) in women.

Methods

Data were collected from 291 consecutive selected post-partum Caucasians using this criterion: ethnicity, age between 21 and 34-year-old new mothers and, 0–3 days after delivery of newborns in the Klaipeda University Hospital, Lithuania. Questionnaires on factors associated with conception were given to patients, and blood samples were collected for genomic DNA extractions as well as for analysis of follicle-stimulating hormone receptor gene polymorphism. Odds ratios (OR) and 95% confidence intervals (CI) for time-to-pregnancy were estimated by multivariate logistic regression. Women with unplanned pregnancies and those who received assisted reproductive technologies were not included in the study.

Results

After adjustment for other possible factors, increased risk for time-to-pregnancy of 12 or more months was associated with: Serine/Serine polymorphism variant (OR = 1.38, 95% CI 1.56–2.71, p = 0.007), age of 30 or more years (OR = 1.95, 95% CI 1.25–2.71, p = 0.015), gynaecological diseases in the past (OR = 2.21, 95% CI 1.12–5.74, p = 0.027), prior contraception use (OR = 1.87, 95% CI 1.14–3.64, p = 0.016), and fertility problems in the past (OR = 1.57, 95% CI 1.16–4.76, p = 0.019).

Conclusion

The results suggest a possible relationship of FSH receptor gene Serine/Serine variant for the lower possibility of conception during the first 12 months of planned conception.

Pharmacogenetic algorithm for individualized controlled ovarian stimulation in assisted reproductive technology cycles

Controlled ovarian stimulation (COS) is crucial for optimizing in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) success. Multiple factors influence the ovarian response to COS, making predictions about oocyte yields not so straightforward. As a result, the ovarian response may be poor or suboptimal, or even excessive, all of which have negative consequences for the affected patient. There is a group of patients that present with a suboptimal response to COS despite normal biomarkers of ovarian reserve, such as AFC and AMH. These patients have a lower number of retrieved oocytes than what was expected based on their ovarian reserve, thus showing the inadequacy of using only the traditional ovarian reserve biomarkers to predict the ovarian response. Suboptimal response to COS might be related to ovarian sensitivity to exogenous gonadotropins modulated by genetic factors. The understanding of the gene polymorphisms related to reproductive function can help to improve the clinical management of this patient population and to explain some of the individual patient variability in response to COS. The development of a pharmacogenetic approach concerning COS in the context of assisted reproduction seems attractive as it might help to understand the relationship between genetic variants and ovarian response to exogenous gonadotropins. The patient's genetic profile could be used to select the most appropriate gonadotropin type, predict the optimal dosage for each drug, develop a cost-effective treatment plan, maximize the success rates, and lastly, decrease the time-to-pregnancy.

The role of gene polymorphisms and AMH level in prediction of poor ovarian response in Egyptian women undergoing IVF procedure

OBJECTIVE

The aim of this study is to assess the role of AMH in prediction of poor ovarian response as well as the relation between ESR ₂ (+ 1730G>A) (rs4986938) and FSHR p.Thr³⁰⁷Ala (c.919A>G, rs6165) SNPs and the poor ovarian response in Egyptian women undergoing IVF procedure. Discovering the genetic variants associated with ovarian response is an important step towards individualized pharmacogenetic protocols of ovarian stimulation.

METHODS

We performed a prospective study on 216 young women with unexplained infertility. Ovarian stimulation was performed according to the GnRH antagonist protocol with a fixed daily morning dose of human menopausal gonadotrophin (HMG). The estrogen receptor (ESR2) (+ 1730G>A) (rs4986938) and FSH receptor p.Thr307Ala (c.919A>G, rs6165) single nucleotide polymorphisms (SNPs) were detected by real-time polymerase chain reaction. Serum FSH, Estradiol (E2) and anti-Müllerian hormone (AMH) levels were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

This study revealed that the low AMH level was highly significantly related to the poor ovarian response (p < 0.001). Furthermore, the frequency of the ESR2 (AA) genotype and the FSHR (Ala³⁰⁷Ala) genotypes were highly significantly associated with the poor ovarian response (p < 0.001).

CONCLUSION

The AMH level in combination with the ESR2 and the FSHR gene polymorphisms predict the poor ovarian response to COH in Egyptian women.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02640976.

Clinical efficacy of recombinant versus highly purified follicle-stimulating hormone according to follicle-stimulating hormone receptor genotype

OBJECTIVE

Conflicting data have been reported on the comparative doses of recombinant follicle-stimulating hormone (rFSH) and urinary highly purified follicle-stimulating hormone (HP-FSH) required for ovarian stimulation. Nothing is known about the clinical efficacy of rFSH or HP-FSH depending on the N680S follicle-stimulating hormone receptor (FSHR) polymorphism. Our aim was to investigate whether the N680S polymorphism of the FSHR gene affects ovarian response with different forms of FSH.

MATERIALS AND METHODS

This retrospective cohort study includes 382 cycles performed at Instituto Bernabeu from 191 oocyte donors. All donors carried out two cycles: one with rFSH and the other one with HP-FSH (group 1, n=63), both with HP-FSH (group 2, n=100) or both with rFSH (group 3, n=28). The results were compared by pairs from each patient. The main outcomes were oocyte yield, metaphase II matured oocytes (MII), days of stimulation, and gonadotropin dosage.

RESULTS

No significant differences were found when we compared the cycles for donors in group 1. However, according to the FSHR polymorphism, statistical differences were shown. For the SS genotype, more oocytes (16.9 vs. 18.4) and MII (12.8 vs. 15.5) were yielded in the HP-FSH cycle. For the NS genotype, more oocyte (20.1 vs. 16.9) and MII (17.4 vs. 14.2) were yielded in the rFSH cycle. For the NN genotype, no differences were found. No differences were found when we compared the cycles in groups 2 and 3 irrespective of the FSHR polymorphism.

CONCLUSION

For the first time, we have shown in a population of egg donors that the N680S FSHR gene polymorphism affects the efficacy of HP-FSH or rFSH. The FSHR genotype is an important factor to determine the dosage and the nature of the gonadotropin selected for ovarian stimulation.

The 'heritability' of domestication and its functional partitioning in the pig

We propose to estimate the proportion of variance explained by regression on genome-wide markers (or genomic heritability) when wild/domestic status is considered the phenotype of interest. This approach differs from the standard Fst in that it can accommodate genetic similarity between individuals in a general form. We apply this strategy to complete genome data from 47 wild and domestic pigs from Asia and Europe. When we partitioned the total genomic variance into components associated to subsets of single nucleotide polymorphisms (SNPs) defined in terms of their annotation, we found that potentially deleterious non-synonymous mutations (9566 SNPs) explained as much genetic variance as the whole set of 25 million SNPs. This suggests that domestication may have affected protein sequence to a larger extent than regulatory or other kinds of mutations. A pathway-guided analysis revealed ovarian steroidogenesis and leptin signaling as highly relevant in domestication. The genomic regression approach proposed in this study revealed molecular processes not apparent through typical differentiation statistics. We propose that at least some of these processes are likely new discoveries because domestication is a dynamic process of genetic selection, which may not be completely characterized by a static metric like Fst. Nevertheless, and despite some particularly influential mutation types or pathways, our analyses tend to rule out a simplistic genetic basis for the domestication process: neither a single pathway nor a unique set of SNPs can explain the process as a whole.

Mouse Models for the Study of Synthesis, Secretion, and Action of Pituitary Gonadotropins

Gonadotropins play fundamental roles in reproduction. More than 30years ago, Cga transgenic mice were generated, and more than 20years ago, the phenotypes of Cga null mice were reported. Since then, numerous mouse strains have been generated and characterized to address several questions in reproductive biology involving gonadotropin synthesis, secretion, and action. More recently, extragonadal expression, and in some cases, functions of gonadotropins in nongonadal tissues have been identified. Several genomic and proteomic approaches including novel mouse genome editing tools are available now. It is anticipated that these and other emerging technologies will be useful to build an integrated network of gonadotropin signaling pathways in various tissues. Undoubtedly, research on gonadotropins will continue to provide new knowledge and allow us transcend from benchside to the bedside.

Clinical Applications of Gonadotropins in the Male

The pituitary gonadotropins, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) play a pivotal role in reproduction. The synthesis and secretion of gonadotropins are regulated by complex interactions among several endocrine, paracrine, and autocrine factors of diverse chemical structure. In men, LH regulates the synthesis of androgens by the Leydig cells, whereas FSH promotes Sertoli cell function and thereby influences spermatogenesis. Gonadotropins are complex molecules composed of two subunits, the α- and β-subunit, that are noncovalently associated. Gonadotropins are decorated with glycans that regulate several functions of the protein including folding, heterodimerization, stability, transport, conformational maturation, efficiency of heterodimer secretion, metabolic fate, interaction with their cognate receptor, and selective activation of signaling pathways. A number of congenital and acquired abnormalities lead to gonadotropin deficiency and hypogonadotropic hypogonadism, a condition amenable to treatment with exogenous gonadotropins. Several natural and recombinant preparations of gonadotropins are currently available for therapeutic purposes. The difference between natural and the currently available recombinant preparations (which are massively produced in Chinese hamster ovary cells for commercial purposes) mainly lies in the abundance of some of the carbohydrates that conform the complex glycans attached to the protein core. Whereas administration of exogenous gonadotropins in patients with isolated congenital hypogonadotropic hypogonadism is a well recognized therapeutic approach, their role in treating men with normogonadotropic idiopathic infertility is still controversial. This chapter concentrates on the main structural and functional features of the gonadotropin hormones and how basic concepts have been translated into the clinical arena to guide therapy for gonadotropin deficit in males.

Testicular Stem Cells Express Follicle-Stimulating Hormone Receptors and Are Directly Modulated by FSH

Testicular spermatogonial stem cells (SSCs) are a heterogeneous population of stem cells, and definitive marker for the most primitive subset that undergoes asymmetric cell division remains to be identified. A novel subpopulation of pluripotent, very small embryonic-like stem cells (VSELs) has been reported in both human and mouse testes. Follicle-stimulating hormone (FSH) receptors (FSHRs) are expressed on Sertoli cells in testis and on granulosa cells in ovary, but recently FSHRs are reported on VSELs in ovaries, bone marrow, and cord blood. The present study was aimed to investigate whether FSHRs are also expressed on testicular stem cells (VSELs and SSCs) and their possible modulation by FSH using intact and chemoablated (25 mg/kg busulfan) mice. Chemoablated testis was a better model to study stem cell biology since quiescent stem cells survive along with the Sertoli cells in the tubules. Proliferating cell nuclear antigen-positive, small-sized cells presumed to be VSELs were clearly visualized, and flow cytometry analysis revealed an increase in LIN^-/CD45^-/SCA-1⁺ VSELs from 0.045±0.008% to 0.1±0.03% of total cells in chemoablated testis after FSH treatment. Very small embryonic-like stem cells expressing nuclear octamer-binding transcription factor 4 (OCT-4) and SSCs with cytoplasmic OCT-4 were detected. Very small embryonic-like stem cells (Oct-4A, Sca-1, Nanog), SSCs (Oct-4), and proliferation (Pcna) specific transcripts were upregulated on FSH treatment. Stem cells expressed FSHR and were stimulated by FSH, and Fshr3 was the predominant transcript maximally modulated by FSH. Nuclear OCT-4 and SCA-1 (stem cell antigen 1) positive VSELs are the most primitive stem cells in testis, and FSH stimulates them to undergo asymmetric cell division including self-renewal and give rise to SSCs, which in turn proliferate rapidly and undergo clonal expansion and further differentiation.

Anti-Mullerian hormone as a predictor of ovarian reserve in ART protocols: the hidden role of thyroid autoimmunity

BACKGROUND

Protocols of controlled ovarian hyper-stimulation (COH) require, as a crucial step, the identification of reliable predictors of ovarian reserve. Anti-Mullerian hormone (AMH) is one of the most reliable predictors of ovarian reserve but other factors including autoimmune thyroid diseases (ATD) have been associated with reduced fertility and poor COH outcome. Aim of the present study was to evaluate the relationship between ATD and AMH, and their role on the outcome of COH.

METHODS

The study group included 288 sub-fertile euthyroid women aged less than 40 years attending a single center for Reproductive Medicine. Among them, 55 were ATD-positive and 233 ATD-negative. The serum levels of AMH, FSH, LH, estradiol (E2), and TSH were measured before COH. The ratio between serum E2 concentration on the day of oocytes pick-up and the total dose of administered recombinant FSH (r-FSH) (E2/r-FSH ratio) was calculated.

RESULTS

The serum levels of AMH were significantly related to E2/r-FSH ratio, total dose of r-FSH and number of M II oocytes, both in ATD-positive and ATD-negative women. Within the low stratum of AMH levels, the presence of ATD did not further affect the outcome of COH. When the serum levels of AMH were in the high stratum, the presence of ATD significantly affected the E2/rFSH ratio, the total dose of r-FSH and the number of M II oocytes.

CONCLUSIONS

The probability of a poor response to COH is high, and independent from ATD, in women with low AMH serum levels. In women with a good ovarian reserve, as assessed by high AMH serum levels, the presence of ATD impairs the outcome of COH.

Low levels of Gαs and Ric8b in testicular sertoli cells may underlie restricted FSH action during infancy in primates

FSH acts via testicular Sertoli cells (Sc) bearing FSH receptor (FSH-R) for regulating male fertility. Despite an adult-like FSH milieu in infant boys and monkeys, spermatogenesis is not initiated until the onset of puberty. We used infant and pubertal monkey Sc to reveal the molecular basis underlying developmental differences of FSH-R signaling in them. Unlike pubertal Sc, increasing doses of FSH failed to augment cAMP production by infant Sc. The expression of Gαs subunit and Ric8b, which collectively activate adenylyl cyclase (AC) for augmenting cAMP production and gene transcription, were significantly low in infant Sc. However, forskolin, which acts directly on AC bypassing FSH-R, augmented cAMP production and gene transcription uniformly in both infant and pubertal Sc. FSH-induced Gαs mRNA expression was higher in pubertal Sc. However, Gαi-2 expression was down-regulated by FSH in pubertal Sc, unlike infant Sc. FSH failed, but forskolin or 8-Bromoadenosine 3',5'-cyclic monophosphate treatment to infant Sc significantly augmented the expression of transferrin, androgen binding protein, inhibin-β-B, stem cell factor, and glial-derived neurotropic factor, which are usually up-regulated by FSH in pubertal Sc during spermatogenic onset. This suggested that lack of FSH mediated down-regulation of Gαi-2 expression and limited expression of Gαs subunit as well as Ric8b may underlie limited FSH responsiveness of Sc during infancy. This study also divulged that intracellular signaling events downstream of FSH-R are in place and can be activated exogenously in infant Sc. Additionally, this information may help in the proper diagnosis and treatment of infertile individuals having abnormal G protein-coupled FSH-R.

Pharmacogenetics of ovarian response

Effective controlled ovarian stimulation (COS) is crucial for IVF outcome. Ovarian response to follicle-stimulating hormone, however, varies widely among women undergoing ovarian stimulation. Advance identification of patients who will elicit a poor or high response to standard treatment would be of great clinical benefit for such patients. Application of pharmacogenetics to ovarian response may predict stimulation success but also help in the adjustment and design of doses prior to treatment. Different studies have examined the impact of variations in follicle-stimulating hormone receptor, biochemical pathways involved in estrogen production and action, folliculogenesis and other aspects. Recently, gene-association studies have tried to identify a number of genetic variations affecting interindividual variability in COS.

Evaluating influence of the genotypes in the follicle-stimulating hormone receptor (FSHR) Ser680Asn (rs6166) polymorphism on poor and hyper-responders to ovarian stimulation: a meta-analysis

Background/aims

Reported associations of controlled ovarian hyperstimulation response (COH) with genotypes of the Ser680Asn (N680S) polymorphism in the follicle stimulating hormone receptor (FSHR) gene have conflicting results.

Methods

PubMed and Embase databases were searched for studies that investigated the N680S polymorphism in the FSHR gene in COH. Parameters used to examine ovarian response were poor and hyper-responses to COH. Using the meta-analytic approach, we estimated ovarian response risk (odds ratio [OR] with 95% confidence intervals) according to genotype.

Results

Our findings showed that SS genotype carriers were most likely to be poor responders (OR 1.61, p = 0.08) compared to the NN and NS genotypes which showed no associations (OR 0.93-0.95, p = 0.75-0.78). Heterogeneity of these pooled ORs warranted examining its sources. We detected outlying studies in each of the three N680S genotypes. Omitting these outliers erased the heterogeneity of the recalculated pooled outcomes. It also materially altered the SS effects where carriers became slightly unlikely to be poor responders (OR 0.90, p = 0.52). The S allele carrier effect was modulated for poor responders (OR 1.24, p = 0.39) in the Non-Hispanic Caucasian (NHC) subgroup. The likelihood of the S allele carriers (OR 1.47, p = 0.02) and the unlikelihood of the N allele carriers (OR 0.64, p = 0.007) were significant in our hyper-response findings. Confined to NHC retained significance of the S allele effects (OR 1.57, p = 0.01) but not among the N allele carriers (OR 0.68, p = 0.18).

Conclusions

In summary, this is a meta-analytical confirmation of the FSHR SS genotype role in COH response. Hyper-responder analysis strengths lie on the non-heterogeneity and robustness of its results. Non-robustness and heterogeneity of the poor-responder results compose its limitations. Thus, poor response findings probably require caution as to the interpretation as a susceptibility marker for ovarian response.

Electronic supplementary material

The online version of this article (doi:10.1186/s13048-014-0122-2) contains supplementary material, which is available to authorized users.

Silencing D. melanogaster lgr1 impairs transition from larval to pupal stage

G protein-coupled receptors (GPCRs) play key roles in a wide diversity of physiological processes and signalling pathways. The leucine-rich repeats containing GPCRs (LGRs) are a subfamily that is well-conserved throughout most metazoan phyla and have important regulatory roles in vertebrates. Here, we report on the critical role of Drosophila melanogaster LGR1, the fruit fly homologue of the vertebrate glycoprotein hormone receptors, in development as a factor involved in the regulation of pupariation. Transcript profiling revealed that lgr1 transcripts are most abundant in third instar larvae and adult flies. The tissues displaying the highest transcript levels were the hindgut, the rectum and the salivary glands. Knockdown using RNA interference (RNAi) demonstrated that white pupa formation was severely suppressed in D. melanogaster lgr1 RNAi larvae. Associated with this developmental defect was a reduced ecdysteroid titer, which is in line with significantly reduced transcript levels detected for the Halloween genes shadow (sad) and spookier (spok) in the third instar lgr1 RNAi larvae compared to the control condition.

Genotyping common FSHR polymorphisms based on competitive amplification of differentially melting amplicons (CADMA)

PURPOSE

To provide an improved platform for simple, reliable, and cost-effective genotyping.

BACKGROUND

Modern fertility treatments are becoming increasingly individualized in an attempt to optimise the follicular response and reproductive outcome, following controlled ovarian stimulation. As the field of pharmacogenetics evolve, genetic biomarkers such as polymorphisms of the follicle stimulating hormone receptor (FSHR) may be included as a predictive tool for individualized fertility treatment. However, the currently available genotyping methods are expensive, time-consuming or have a limited analytical sensitivity. Here, we present a novel version of "competitive amplification of differentially melting amplicons" (CADMA), providing an improved platform for simple, reliable, and cost-effective genotyping.

METHODS

Two CADMA based assays were designed for the two common polymorphisms of the FSHR gene: rs6165 (c.919A > G, p. Thr307Ala, FSHR 307) and rs6166 (c.2039A > G, p. Asn680Ser, FSHR 680). To evaluate the reliability of the new CADMA-based assays, the genotyping results were compared with two conventional PCR based genotyping methods; allele-specific PCR (AS-PCR) and Sanger sequencing.

RESULTS

The genotype frequencies for both polymorphisms were 35 % (TT), 42 % (CT), and 23 % (CC), respectively. A 100 % accordance was observed between the CADMA-based genotyping results and sequencing results, whereas 5 discrepancies were observed between the AS-PCR results and the CADMA-based genotyping results. Comparing the CADMA-based assays to (AS-PCR) and Sanger sequencing, the CADMA based assays showed an improved analytical sensitivity and a wider applicability.

CONCLUSIONS

The new assays provide a reliable, fast and user-friendly genotyping method facilitating a wider implication in clinical practise.

Reproductive physiology in young men is cumulatively affected by FSH-action modulating genetic variants: FSHR -29G/A and c.2039 A/G, FSHB -211G/T

Follicle-Stimulating Hormone Receptor (FSHR) -29G/A polymorphism (rs1394205) was reported to modulate gene expression and reproductive parameters in women, but data in men is limited. We aimed to bring evidence to the effect of FSHR -29G/A variants in men. In Baltic young male cohort (n = 982; Estonians, Latvians, Lithuanians; aged 20.2±2.0 years), the FSHR -29 A-allele was significantly associated with higher serum FSH (linear regression: effect 0.27 IU/L; P = 0.0019, resistant to Bonferroni correction for multiple testing) and showed a non-significant trend for association with higher LH (0.19 IU/L) and total testosterone (0.93 nmol/L), but reduced Inhibin B (−7.84 pg/mL) and total testes volume (effect −1.00 mL). Next, we extended the study and tested the effect of FSHR gene haplotypes determined by the allelic combination of FSHR -29G/A and a well-studied variant c.2039 A/G (Asn680Ser, exon 10). Among the FSHR -29A/2039G haplotype carriers (A-Ser; haplotype-based linear regression), this genetic effect was enhanced for FSH (effect 0.40 IU/L), Inhibin B (−16.57 pg/mL) and total testes volume (−2.34 mL). Finally, we estimated the total contribution of three known FSH-action modulating SNPs (FSHB -211G/T; FSHR -29G/A, c.2039 A/G) to phenotypic variance in reproductive parameters among young men. The major FSH-action modulating SNPs explained together 2.3%, 1.4%, 1.0 and 1.1% of the measured variance in serum FSH, Inhibin B, testosterone and total testes volume, respectively. In contrast to the young male cohort, neither FSHR -29G/A nor FSHR haplotypes appeared to systematically modulate the reproductive physiology of oligozoospermic idiopathic infertile patients (n = 641, Estonians; aged 31.5±6.0 years). In summary, this is the first study showing the significant effect of FSHR -29G/A on male serum FSH level. To account for the genetic effect of known common polymorphisms modulating FSH-action, we suggest haplotype-based analysis of FSHR SNPs (FSHR -29G/A, c.2039 A/G) in combination with FSHB -211G/T testing.

Mechanisms in endocrinology: Genetics of FSH action: a 2014-and-beyond view

OBJECTIVE

To assess the pharmacogenetic potential of FSH for infertility treatment.

DESIGN

Review of the literature and genomic databases.

METHODS

Single-nucleotide polymorphism (SNP) assessed: rs6166 (c.2039A>G, p.N680S), rs6165 (c.919A>G, p.T307A), rs1394205 (c.-29G>A) in FSHR, and rs10835638 (c.-211G>T) in FSHB. Literature search via PubMed. Blast analysis of genomic information available in the NCBI nucleotide database. Comparison of allele frequency and haplotype distribution using the http://spsmart.cesga.estool.

RESULTS

All these SNPs appear first in Homo, result in reduced FSH action, and are present with variable frequencies and combinations worldwide. Stringent clinical studies demonstrate that the FSHR genotype influences serum FSH levels and gonadal response in both sexes. Serum FSH levels depend on the -211G>T SNP, influencing transcriptional activity of the FSHB promoter. Genotypes reducing FSH action are overrepresented in infertile subjects.

CONCLUSIONS

Although the clinical relevance of the FSHR polymorphisms alone is limited, the combination of FSHR and FSHB genotypes has a much stronger impact than either one alone in both sexes. About 20% of people are carriers of the alleles associated with lower serum FSH levels/reduced FSHR expression or activity, possibly less favorable for reproduction. Prospective studies need to investigate whether stratification of infertile patients according to their FSHR-FSHB genotypes improves clinical efficacy of FSH treatment compared with the current, naïve approach. A relative enrichment of less favorable FSHR-FSHB genotypes may be related to changes in human reproductive strategies and be a marker of some health-related advantage at the cost of reduced fertility.

Mutations and polymorphisms in FSH receptor: functional implications in human reproduction

FSH brings about its physiological actions by activating a specific receptor located on target cells. Normal functioning of the FSH receptor (FSHR) is crucial for follicular development and estradiol production in females and for the regulation of Sertoli cell function and spermatogenesis in males. In the last two decades, the number of inactivating and activating mutations, single nucleotide polymorphisms, and spliced variants of FSHR gene has been identified in selected infertile cases. Information on genotype-phenotype correlation and in vitro functional characterization of the mutants has helped in understanding the possible genetic cause for female infertility in affected individuals. The information is also being used to dissect various extracellular and intracellular events involved in hormone-receptor interaction by studying the differences in the properties of the mutant receptor when compared with WT receptor. Studies on polymorphisms in the FSHR gene have shown variability in clinical outcome among women treated with FSH. These observations are being explored to develop molecular markers to predict the optimum dose of FSH required for controlled ovarian hyperstimulation. Pharmacogenetics is an emerging field in this area that aims at designing individual treatment protocols for reproductive abnormalities based on FSHR gene polymorphisms. The present review discusses the current knowledge of various genetic alterations in FSHR and their impact on receptor function in the female reproductive system.

Signaling of an allosteric, nanomolar potent, low molecular weight agonist for the follicle-stimulating hormone receptor

Follicle-stimulating hormone (FSH) activates FSH receptors (FSHR) in granulosa cells to induce follicle differentiation, growth and estradiol production. FSH is used clinically to treat female infertility and is administered by injection. To increase patient convenience and compliance, compound homogeneity and composition, low molecular weight (LMW), orally bioavailable, FSHR agonists are now being developed to replace FSH. In this study, we present the signaling mechanisms of a newly developed LMW dihydropyridine agonist of the FSHR, Org 214444-0. Org 214444-0 is shown to be a stereoselective, nanomolar potent FSHR agonist and selective over the structurally related LHR and TSHR. Org 214444-0 is an allosteric agonist interacting with the transmembrane region of the FSHR. When co-incubated with FSH, Org 214444-0 augments FSH's potency in binding (6.5-fold) and adenylyl cyclase/cAMP activation (3.5-fold) in a concentration-dependent manner. Like FSH, Org 214444-0 induces FSHR internalization and is only marginally effective in stimulating phospholipase C. Moreover, Org 214444-0 stimulates cAMP and estradiol production in human granulosa cells in culture and supports the follicular phase in mature female rats. We conclude that Org 214444-0 is a bonafide FSHR agonist.

Study in 1790 Baltic men: FSHR Asn680Ser polymorphism affects total testes volume

Follicle-stimulating hormone receptor (FSHR) contains two common linked polymorphisms, Thr307Ala (rs6165) and Asn680Ser (rs6166), shown to modulate ovarian function in women. The effect on male fertility and reproductive parameters has been inconclusive. We studied FSHR Asn680Ser polymorphism in a large study group (n = 1790) from the Baltic countries. The population-based Baltic male cohort (Estonians, Latvians, Lithuanians; n = 1052) and Estonian oligo-/azoospermic (sperm concentration <20 × 10⁶/mL) idiopathic infertile patients (n = 738) were genotyped for the FSHR Asn680Ser using PCR-RFLP. Genetic associations were tested using linear regression under additive model and results were combined in meta-analysis. No statistical difference was detected in allelic distribution of the FSHR Asn680Ser between the Baltic cohort and Estonian male infertility group. A consistent significant association was detected between the FSHR Ser680 allele and lower total testes volume in both, the Baltic cohort (p = 0.010, effect = −1.16 mL) and Estonian idiopathic infertility group (p = 0.007, effect = −1.77 mL). In meta-analysis, the statistical significance was enhanced (p = 0.000066, effect = −1.40 mL). Meta-analysis supported further associations with moderate effect between the FSHR Ser680 variant and higher serum FSH (p = 0.072), lower Inhibin B (p = 0.037) and total testosterone (p = 0.034). No statistically significant associations were identified with serum LH and estradiol, and sperm parameters. In conclusion, the study in 1790 Baltic men shows statistically highly significant association of the FSHR Asn680Ser with total testes volume and supportive association with serum reproductive hormone levels indicative to the functional effect of the alternative FSHR variants on male reproductive physiology.

The molecular basis of impaired follicle-stimulating hormone action: evidence from human mutations and mouse models

The pituitary gonadotropin follicle-stimulating hormone (FSH) interacts with its membrane-bound receptor to produce biologic effects. Traditional functions of FSH include follicular development and estradiol production in females, and the regulation of Sertoli cell action and spermatogenesis in males. Knockout mice for both the ligand (Fshb) and the receptor (Fshr) serve as models for FSH deficiency, while Fshb and Fshr transgenic mice manifest FSH excess. In addition, inactivating mutations of both human orthologs (FSHB and FSHR) have been characterized in a small number of patients, with phenotypic effects of the ligand disruption being more profound than those of its receptor. Activating human FSHR mutants have also been described in both sexes, leading to a phenotype of normal testis function (male) or spontaneous ovarian hyperstimulation syndrome (females). As determined from human and mouse models, FSH is essential for normal puberty and fertility in females, particularly for ovarian follicular development beyond the antral stage. In males, FSH is necessary for normal spermatogenesis, but there are differences in human and mouse models. The FSHB mutations in humans result in azoospermia; while FSHR mutations in humans and knockouts of both the ligand and the receptor in mice affect testicular function but do not result in absolute infertility. Available evidence also indicates that FSH may also be necessary for normal androgen synthesis in males and females.