Combined effects of the variants FSHB -211G>T and FSHR 2039A>G on male reproductive parameters

APHRODITE criteria: addressing male patients with hypogonadism and/or infertility owing to altered idiopathic testicular function

RESEARCH QUESTION

Can a novel classification system of the infertile male - 'APHRODITE' (Addressing male Patients with Hypogonadism and/or infeRtility Owing to altereD, Idiopathic TEsticular function) - stratify different subgroups of male infertility to help scientists to design clinical trials on the hormonal treatment of male infertility, and clinicians to counsel and treat the endocrinological imbalances in men and, ultimately, increase the chances of natural and assisted conception?

DESIGN

A collaboration between andrologists, reproductive urologists and gynaecologists, with specialization in reproductive medicine and expertise in male infertility, led to the development of the APHRODITE criteria through an iterative consensus process based on clinical patient descriptions and the results of routine laboratory tests, including semen analysis and hormonal testing.

RESULTS

Five patient groups were delineated according to the APHRODITE criteria; (1) Hypogonadotrophic hypogonadism (acquired and congenital); (2) Idiopathic male infertility with lowered semen analysis parameters, normal serum FSH and normal serum total testosterone concentrations; (3) A hypogonadal state with lowered semen analysis parameters, normal FSH and reduced total testosterone concentrations; (4) Lowered semen analysis parameters, elevated FSH concentrations and reduced or normal total testosterone concentrations; and (5) Unexplained male infertility in the context of unexplained couple infertility.

CONCLUSION

The APHRODITE criteria offer a novel and standardized patient stratification system for male infertility independent of aetiology and/or altered spermatogenesis, facilitating communication among clinicians, researchers and patients to improve reproductive outcomes following hormonal therapy. APHRODITE is proposed as a basis for future trials of the hormonal treatment of male infertility.

Spontaneous alterations in semen parameters are associated with age, accessory gland function and the FSHB c.-211G>T variant

BACKGROUND

There is a strong within-subject alteration of semen parameters in men with infertility. However, it remains unknown in which subgroup variations are likely to occur and which semen parameters are affected.

OBJECTIVE

To evaluate parameters associated with spontaneous alterations in semen analysis.

PATIENTS AND METHODS

We retrospectively selected 3456 men with infertility without known causes affecting spermatogenesis or sperm output for analysis of repeated ejaculate samples. Exclusion criteria comprised sperm concentration <1 million/mL, abnormal follicle-stimulating hormone or low testosterone, and low bitesticular volume (<10 mL). Grouped linear two-level nested mixed-effect models were applied. The analyzed parameters included abstinence time, bitesticular volume, age, accessory gland markers, follicle-stimulating hormone, and FSHB c.-211 variants.

RESULTS

Groups include A (n = 397): ≥1.0 to <5.0 million/mL, B (n = 708): ≥5.0 to <15.0 million/mL, and C (n = 2351): ≥15.0 million/mL. Groups A, B, and C: changes in ejaculate volume were associated with alterations in total sperm count and motility (p < 0.003). Changes were, controlled for abstinence time (p < 0.001), related to α-glucosidase, fructose, or zinc (p = 0.005-0.02). Group A + B: fluctuations in follicle-stimulating hormone level influenced sperm concentration/count (p = 0.004-0.02), albeit only in men with FSHB c.-211 GG (p = 0.007-0.02). T-allele carriers did not show changes in follicle-stimulating hormone levels (p > 0.1). Group B: age <50 years (p = 0.007-0.01) and normal bitesticular volume (p = 0.008-0.02) were associated with spontaneous increases in sperm concentration, count, and motility.

CONCLUSION

Semen parameters exhibit intra-individual alterations associated with organic, hormonal, and genetic variables. Changes are pronounced in younger men with normal bitesticular volume and oligozoospermia to almost normozoospermia. The effect is modulated by abstinence time, accessory gland function, and fluctuations in follicle-stimulating hormone level, which is bound to FSHB c.-211G>T variant. Judgment of semen analysis should be based on two semen samples, with abstinence times between 4 and 5 days. As a future perspective, it might be investigated whether younger men with normal bitesticular volume who are unable to elicit increases in serum follicle-stimulating hormone (FSHB c.-211 genotype of GT/TT) benefit from improving accessory gland function and increasing follicle-stimulating hormone.

Zbtb40 Deficiency Leads to Morphological and Phenotypic Abnormalities of Spermatocytes and Spermatozoa and Causes Male Infertility

Studies on the gene regulation of spermatogenesis are of unusual significance for maintaining male reproduction and treating male infertility. Here, we have demonstrated, for the first time, that a loss of ZBTB40 function leads to abnormalities in the morphological and phenotypic characteristics of mouse spermatocytes and spermatids as well as male infertility. We revealed that Zbtb40 was expressed in spermatocytes of mouse testes, and it was co-localized with γH2AX in mouse secondary spermatocytes. Interestingly, spermatocytes of Zbtb40 knockout mice had longer telomeres, compromised double-strand break (DSB) repair in the sex chromosome, and a higher apoptosis ratio compared to wild-type (WT) mice. The testis weight, testicular volume, and cauda epididymis body weight of the Zbtb40^+/- male mice were significantly lower than in WT mice. Mating tests indicated that Zbtb40^+/- male mice were able to mate normally, but they failed to produce any pups. Notably, sperm of Zbtb40^+/- mice showed flagellum deformities and abnormal acrosome biogenesis. Furthermore, a ZBTB40 mutation was associated with non-obstructive azoospermia. Our results implicate that ZBTB40 deficiency leads to morphological and phenotypic abnormalities of spermatocytes and spermatids and causes male infertility. This study thus offers a new genetic mechanism regulating mammalian spermatogenesis and provides a novel target for gene therapy in male infertility.

Follicle-stimulating hormone treatment for male factor infertility

Follicle-stimulating hormone (FSH) treatment has been proven effective in stimulating spermatogenesis and improving the reproductive ability of men with hypogonadotropic hypogonadism, while the usefulness of such a treatment in infertile patients with normal pituitary function is restricted to a subgroup of responders that, however, cannot be identified by the current diagnostic tools before treatment. In this review we summarize the role played by FSH in the modulation of spermatogenesis, the effect of FSH treatment at a standard replacement dose and at higher dose on sperm parameters, spontaneous and in vitro fertilization pregnancy rates, and the efforts made to identify possible responders to FSH treatment.

Male infertility and gonadotropin treatment: What can we learn from real-world data?

Gonadotropin therapy to treat specific male infertility disorders associated with hypogonadotropic hypogonadism is evidence-based and effective in restoring spermatogenesis and fertility. In contrast, its use to improve fertility in men with idiopathic oligozoospermia or nonobstructive azoospermia remains controversial, despite being widely practiced. The existence of two major inter-related pathways for spermatogenesis, including FSH and intratesticular testosterone, provides a rationale for empiric hormone stimulation therapy in both eugonadal and hypogonadal males with idiopathic oligozoospermia or nonobstructive azoospermia. Real-world data (RWD) on gonadotropin stimulating for these patient subsets, mainly using human chorionic gonadotropin and follicle-stimulating hormone, accumulated gradually, showing a positive therapeutic effect in some patients, translated by increased sperm production, sperm quality, and sperm retrieval rates. Although more evidence is needed, current insights from RWD research indicate that selected male infertility patients might be managed more effectively using gonadotropin therapy, with potential gains for all parties involved.

Real-world evidence analysis of the follicle-stimulating hormone use in male idiopathic infertility

Male idiopathic infertility remains a therapeutic challenge in the couple infertility management. In this setting, an empirical treatment with follicle-stimulating hormone (FSH) is allowed, although not recommended. Twenty-one clinical trials and four meta-analyses highlighted an overall increased pregnancy rate in case of FSH administration, but the indiscriminate FSH prescription is still unsupported by clinical evidence in idiopathic infertility. This context could represent an example in which real-world data (RWD) could add useful information. From a nationwide clinical practice survey performed in Italy, emerged the clinicians' attitude to prescribe FSH in the case of impaired semen with a significant improvement of semen parameters, identifying FSH treatment as a therapeutic card in the real-life management. Although more robust data are still needed to optimize FSH treatment in male idiopathic infertility, RWD should be included in the body of evidence considered in healthcare decision-making.

Immune and spermatogenesis-related loci are involved in the development of extreme patterns of male infertility

We conducted a genome-wide association study in a large population of infertile men due to unexplained spermatogenic failure (SPGF). More than seven million genetic variants were analysed in 1,274 SPGF cases and 1,951 unaffected controls from two independent European cohorts. Two genomic regions were associated with the most severe histological pattern of SPGF, defined by Sertoli cell-only (SCO) phenotype, namely the MHC class II gene HLA-DRB1 (rs1136759, P = 1.32E-08, OR = 1.80) and an upstream locus of VRK1 (rs115054029, P = 4.24E-08, OR = 3.14), which encodes a protein kinase involved in the regulation of spermatogenesis. The SCO-associated rs1136759 allele (G) determines a serine in the position 13 of the HLA-DRβ1 molecule located in the antigen-binding pocket. Overall, our data support the notion of unexplained SPGF as a complex trait influenced by common variation in the genome, with the SCO phenotype likely representing an immune-mediated condition.

A GWAS in a large case-control cohort of European ancestry identifies two genomic regions, the MHC class II gene HLA-DRB1 and an upstream locus of VRK1, that are associated with the most severe phenotype of spermatogenic failure.

The impact of male factors and their correct and early diagnosis in the infertile couple's pathway: 2021 perspectives

PURPOSE

The current clinical practice in reproductive medicine should pose the couple at the centre of the diagnostic-therapeutic management of infertility and requires intense collaboration between the andrologist, the gynaecologist and the embryologist. The andrologist, in particular, to adequately support the infertile couple, must undertake important biological, psychological, economical and ethical task. Thus, this paper aims to provide a comprehensive overview of the multifaceted role of the andrologist in the study of male factor infertility.

METHODS

A comprehensive Medline, Embase and Cochrane search was performed including publications between 1969 and 2021.

RESULTS

Available evidence indicates that a careful medical history and physical examination, followed by semen analysis, always represent the basic starting points of the diagnostic work up in male partner of an infertile couple. Regarding treatment, gonadotropins are an effective treatment in case of hypogonadotropic hypogonadism and FSH may be used in men with idiopathic infertility, while evidence supporting other hormonal and nonhormonal treatments is either limited or conflicting. In the future, pharmacogenomics of FSHR and FSHB as well as innovative compounds may be considered to develop new therapeutic strategies in the management of infertility.

CONCLUSION

To provide a high-level of care, the andrologist must face several critical diagnostical and therapeutical steps. Even though ART may be the final and decisive stage of this decisional network, neglecting to treat the male partner may ultimately increase the risks of negative outcome, as well as costs and psychological burden for the couple itself.

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.

Genetic variants of gonadotrophins and their receptors: Impact on the diagnosis and management of the infertile patient

This narrative review is concerned with genetic variants of the genes encoding gonadotrophin subunits and their receptors, as well as their implications into the diagnosis and treatment of infertility. We first review briefly the basics of molecular biology and biochemistry of gonadotrophin and gonadotrophin receptor structure and function, then describe the phenotypic effects of polymorphisms and mutations of these genes, followed by diagnostic aspects. We will then summarise the information that inactivating gonadotrophin receptor mutations have provided about the controversial topic of extragonadal gonadotrophin action. Finally, we will close with the current and future therapeutic approaches on patients with gonadotrophin and their receptor mutations.

FSHB Genotype Identified as a Relevant Diagnostic Parameter Revealed by Cluster Analysis of Men With Idiopathic Infertility

Introduction and Objectives

About 30-75% of infertile men are diagnosed with idiopathic infertility, thereby lacking major causative factors to explain their impaired fertility status. In this study, we used a large cohort of idiopathic infertile men to determine whether subgroups could be identified by an unbiased clustering approach and whether underlying etiologic factors could be delineated.

Patients and Methods

From our in-house database Androbase®, we retrospectively selected patients (from 2008 to 2018) with idiopathic male infertility (azoo- to normozoospermia) who fit the following selection criteria: FSH ≥ 1 IU/l, testosterone ≥ 8 nmol/l, ejaculate volume ≥ 1.5 ml. Patients with genetic abnormalities or partners with female factors were excluded.For the identified study population (n=2742), we used common andrologic features (somatic, semen and hormonal parameters, including the FSHB c.-211G>T (rs10835638) single nucleotide polymorphism) for subsequent analyses. Cluster analyses were performed for the entire study population and for two sub-cohorts, which were separated by total sperm count (TSC) thresholds: Cohort A (TSC ≥ 1 mill/ejac; n=2422) and Cohort B (TSC < 1 mill/ejac; n=320). For clustering, the partitioning around medoids method was employed, and the quality was evaluated by average silhouette width.

Results

The applied cluster approach for the whole study population yielded two separate clusters, which showed significantly different distributions in bi-testicular volume, FSH and FSHB genotype. Cluster 1 contained all men homozygous for G (wildtype) in FSHB c.-211G>T (100%), while Cluster 2 contained most patients carrying a T allele (>96.6%). In the analyses of sub-cohorts A/B, two clusters each were formed too. Again, the strongest segregation markers between the respective clusters were bi-testicular volume, FSH and FSHB c.-211G>T.

Conclusion

With this first unbiased approach for revealing putative subgroups within a heterogenous group of idiopathic infertile men, we did indeed identify distinct patient clusters. Surprisingly, across all diverse phenotypes of infertility, the strongest segregation markers were FSHB c.-211G>T, FSH, and bi-testicular volume. Further, Cohorts A and B were significantly separated by FSHB genotype (wildtype vs. T-allele carriers), which supports the notion of a contributing genetic factor. Consequently, FSHB genotyping should be implemented as diagnostic routine in patients with idiopathic infertility.

Follicle-stimulating hormone (FSH) receptor gene polymorphisms in Iraqi patients with non-obstructive azoospermia

Background: Follicle-stimulating hormone (FSH) is a pivotal hormone for male fertility, and its action on gonads is exerted by FSH receptors (FSHRs). Objectives: To examine whether the presence of FSHR gene single nucleotide polymorphisms (SNPs), G919A and A2039G, involved in non-obstructive azoospermia (NOA) in Iraqi infertile men. Methods: Two common SNPs, A919G and A2039G, in the FSHR gene were analyzed in 104 subjects (70 infertile patients with NOO: 33 NOA patients were not receiving treatment and 37 were on infertility treatment, and 34 normozoospermic fertile men as controls). Results: The results revealed that the homozygous wild genotype (AA) of rs6165 FSHR gene SNP was more abundant than (AG) and (GG) genotypes in both groups of infertile NOA patients with a frequency of 49% in those who untreated, 81% in patients undergoing treatment and in the control group 41%. Whereas, the highest percentage of heterozygous genotype (AG) in the fertile control group was 41% when compared to NOApatients with a genotype frequency of 24% (for those who untreated) and 11% (for patients on treatment), respectively; with (A) allele frequency of 86% and the observed frequency of (G) allele was only 14% in the patients’ group as compared to that of controls that were  (65 %) and (35 %), respectively. The rs6166 genotyping revealed that the homozygous wild genotype (GG) of FSHR gene was more abundant than (AG) and (AA) genotypes in NOA patients receiving infertility treatment with a frequency of (68%), in NOA patients who didn’t receive treatment 49%, while the lowest frequency was detected in the healthy fertile control group (47%). Conclusions: These results support the evidence that rs6165 and rs6166, FSHR SNPs, might be involved in the pathogenesis and protection against NOA, respectively.

Pituitary response to GnRH stimulation tests in different FSHB-211 G/T genotypes

STUDY QUESTION

Does pituitary response to a GnRH stimulation test differ according to the different FSHB-211 G/T genotypes?

SUMMARY ANSWER

The promoter polymorphism FSHB-211 G > T affects the pituitary response to exogenous GnRH stimulation by reducing FSH and increasing LH outputs.

WHAT IS KNOWN ALREADY

The FSHB-211 G > T single nucleotide polymorphism (SNP) is known to affect pituitary FSH output by impairing the transcriptional activity of FSHB.

STUDY DESIGN, SIZE, DURATION

This was a cross-sectional, retrospective study on 67 male subjects (mean age: 24.6 ± 10.3 years) undergoing a GnRH stimulation test for diagnostic purposes in cases of secondary hypogonadism.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A GnRH stimulation test was performed by administering an i.v. bolus of 100 µg of the GnRH-analogue gonadorelin acetate to all patients, with blood samples drawn from the cubital vein immediately prior to injection (T0) and 30 (T1) and 45 minutes (T2) after. Clinical and genetic data were retrieved from a computerized database. Linear longitudinal mixed-effect models were used to assess the effects of SNP genotype on FSH and LH levels over time via additive and recessive models.

MAIN RESULTS AND THE ROLE OF CHANCE

An overall marked increase in serum FSH and LH following administration i.v. of 100 µg of an LHRH-analogue was found (P < 0.0001 for linear trend, both models). Peak levels of LH were significantly higher in TT carriers than in GT and GG carriers (P = 0.012); no significant between-groups difference was found concerning stimulated FSH levels. In both the additive and recessive model, the main effect of T allele(s) did not reach statistical significance concerning FSH levels (P = 0.9502 and P = 0.8576, respectively), yet interaction effects over time demonstrated an attenuated response in T-allele carriers compared to the GG-allele carriers (P = 0.0219 and P = 0.0276). Main and interaction effects for LH were significant in both the additive (P = 0.0022 and P = 0.0013, respectively) and recessive model (P = 0.0025 and P = 0.0016, respectively).

LIMITATIONS, REASONS FOR CAUTION

Given the retrospective nature of the study and the small number of TT carriers, results should be interpreted with caution.

WIDER IMPLICATIONS OF THE FINDINGS

The FSHB c.-211G>T polymorphism might result in an impaired response to endogenous, as well as exogenous, GnRH stimulation. This finding might contribute to the clinical phenotype of reduced testicular volume and sperm count for patients carrying one or two T alleles.

STUDY FUNDING/COMPETING INTEREST(S)

Parts of the study were supported by the German Research Foundation (CRU326 Male Germ Cells). On behalf of all authors, the corresponding author states that there is no conflict of interest.

TRIAL REGISTRATION NUMBER

NA.

FSHB Transcription is Regulated by a Novel 5' Distal Enhancer With a Fertility-Associated Single Nucleotide Polymorphism

The pituitary gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone, signal the gonads to regulate male and female fertility. FSH is critical for female fertility as it regulates oocyte maturation, ovulation, and hormone synthesis. Multiple genome-wide association studies (GWAS) link a 130 Kb locus at 11p14.1, which encompasses the FSH beta-subunit (FSHB) gene, with fertility-related traits that include polycystic ovary syndrome, age of natural menopause, and dizygotic twinning. The most statistically significant single nucleotide polymorphism from several GWAS studies (rs11031006) resides within a highly conserved 450 bp region 26 Kb upstream of the human FSHB gene. Given that sequence conservation suggests an important biological function, we hypothesized that the region could regulate FSHB transcription. In luciferase assays, the conserved region enhanced FSHB transcription and gel shifts identified a binding site for Steroidogenic factor 1 (SF1) contributing to its function. Analysis of mouse pituitary single-cell ATAC-seq demonstrated open chromatin at the conserved region exclusive to a gonadotrope cell-type cluster. Additionally, enhancer-associated histone markers were identified by immunoprecipitation of chromatin from mouse whole pituitary and an immortalized mouse gonadotrope-derived LβT2 cell line at the conserved region. Furthermore, we found that the rs11031006 minor allele upregulated FSHB transcription via increased SF1 binding to the enhancer. All together, these results identify a novel upstream regulator of FSHB transcription and indicate that rs11031006 can modulate FSH levels.

FSHB and FSHR gene variants exert mild modulatory effect on reproductive hormone levels and testis size but not on semen quality: A study of 2020 men from the general Danish population

BACKGROUND

Spermatogenesis depends on stimulation by follicle-stimulating hormone (FSH) which binds to FSH receptors (FSHR) on testicular Sertoli cells. Three FSH-related single-nucleotide polymorphisms (SNPs), FSHB -211G>T (rs10835638), FSHR -29G>A (rs1394205) and FSHR 2039A>G (rs6166) affect FSH action, and have been suggested to affect testicular function, but the evidence is uncertain.

OBJECTIVE

To describe the associations between the three SNPs and testicular function in a large and well-characterised cohort of men from the general population.

MATERIALS AND METHODS

A cross-sectional study of 2020 Danish men unselected regarding testicular function. Outcome variables were semen parameters, reproductive hormones and testis size. Genotyping was done by competitive allele-specific quantitative PCR. Differences in genotype frequencies were tested by chi-square test and associations between genotypes and outcomes were assessed by multivariate linear regressions.

RESULTS

The SNPs affected serum FSH; carriers of the variant affecting FSH secretion (FSHB -211G>T) had lower FSH levels while carriers of variants affecting receptor expression (FSHR -29G>A) and receptor sensitivity (FSHR 2039A>G) had higher FSH levels. Carriers of FSHB -211G>T had lower calculated free testosterone/LH ratio. Although both FSHB -211G>T and FSHR 2039A>G were associated with smaller testis size, no clear association was detected in relation to any semen parameters, except a lower total number of morphologically normal spermatozoa in the heterozygous carriers of the FSHB -211G>T DISCUSSION AND CONCLUSION: The studied polymorphisms have only minor modulating influence on testis size and function in healthy men. We detected subtle effects of the three SNPs on FSH levels, but also effects of FSHB -211G>T on calculated free testosterone/LH ratio, compatible with altered Leydig cell function. Thus, the role of these FSH-related polymorphisms is complex and modest in men with normal testicular function, but the possible importance of FSH polymorphisms in men with impaired testicular function should be evaluated in future studies in more detail.

The 2039 A/G FSH receptor gene polymorphism influences glucose metabolism in healthy men

OBJECTIVE

To assess the role of c. 2039 A/G (p. Asp680Ser) (rs6166) and c. -29 G/A (rs1394205) follicle-stimulating hormone receptor (FSHR) gene single nucleotide polymorphisms (SNPs) in a cohort of healthy men.

METHODS

One-hundred twenty-seven healthy men underwent evaluation of the anthropometric parameters, assessment of metabolic and lipid profile, measurement FSH serum levels, and genotyping of both the aforementioned FSHR SNPs. Data grouped according to the FSHR rs6166 or rs1394205 genotypes underwent to statistical analysis.

MAIN RESULTS

The three groups of men for each FSHR SNP did not differ statistically significantly for body mass index and serum FSH levels. As for FSHR rs6166 SNP, glucose levels were significantly lower in men with the GG genotype compared with those with the AA genotype. Men with AG had lower insulin levels and HOMA index values compared with those carrying the genotype AA (p < 0.05). The GG group showed a negative correlation between serum FSH levels and insulin and between serum FSH levels and HOMA index (p < 0.05). In contrast, men grouped according to the FSHR rs1394205 genotype showed no significant difference in blood glucose, serum insulin levels, and HOMA index. The AG group showed a negative correlation between FSH insulin and between serum FSH levels and HOMA index (p < 0.05).

CONCLUSIONS

Men with the genotype GG of the FSHR rs6166 SNP have lower blood glucose levels than those with the AA genotype. Their FSH levels inversely correlated with insulin and HOMA index. In contrast, the genotype FSHR rs6166 A/G did not reveal any role of FSH on glucose metabolism in healthy men. The inverse relationship between FSH and insulin or HOMA index in the group with the genotype GG of the FSHR rs6166 SNP suggests a possible cross-talk between FSH and insulin.

Combined Effects of the FSHR 2039 A/G and FSHR -29 G/A Polymorphisms on Male Reproductive Parameters

PURPOSE

The aim of this study was to evaluate the combined effect of FSHR 2039 A/G and FSHR -29 G/A single nucleotide polymorphisms (SNPs) on the male reproductive function in a cohort of Sicilian men.

MATERIALS AND METHODS

One-hundred thirty Sicilian men were enrolled and underwent blood withdrawal for hormone measurement and FSHR 2039 A/G and FSHR -29 G/A SNP genotyping, testicular volume evaluation by ultrasound scan, and semen analysis. A meta-analysis of the FSHR -29 G/A SNP, evaluated in a previous study of the Sicilian population was done.

RESULTS

No genotype of the FSHR 2039 A/G SNP correlated with serum follicle-stimulating hormone (FSH) levels, testicular volume, sperm concentration, and total sperm count. In contrast, normozoospermic men with FSHR -29 GG and FSHR -29 GA genotypes had significantly lower sperm concentrations compared to men with the FSHR -29 AA genotype. The other sperm parameters did not show any significant difference. The meta-analysis showed no significant difference in serum FSH levels, testicular volume, sperm concentration, and total sperm count between FSHR -29 GG and FSHR -29 AA in Sicilian men. No difference was found even when the two SNPs were evaluated in combination. However, this combination was present, as expected, only in a low proportion (3.8%) of the men studied.

CONCLUSIONS

The SNPs FSHR 2039 A/G and FSHR -29 G/A in combination did not seem to have any effect on male reproductive function in a cohort of Sicilian men. The effect of these SNPs has only been studied in granulosa cells so far. Further studies on their role in Sertoli cells are needed.

Prospects for FSH Treatment of Male Infertility

CONTEXT

Despite the new opportunities provided by assisted reproductive technology (ART), male infertility treatment is far from being optimized. One possibility, based on pathophysiological evidence, is to stimulate spermatogenesis with gonadotropins.

EVIDENCE ACQUISITION

We conducted a comprehensive systematic PubMed literature review, up to January 2020, of studies evaluating the genetic basis of follicle-stimulating hormone (FSH) action, the role of FSH in spermatogenesis, and the effects of its administration in male infertility. Manuscripts evaluating the role of genetic polymorphisms and FSH administration in women undergoing ART were considered whenever relevant.

EVIDENCE SYNTHESIS

FSH treatment has been successfully used in hypogonadotropic hypogonadism, but with questionable results in idiopathic male infertility. A limitation of this approach is that treatment plans for male infertility have been borrowed from hypogonadism, without daring to overstimulate, as is done in women undergoing ART. FSH effectiveness depends not only on its serum levels, but also on individual genetic variants able to determine hormonal levels, activity, and receptor response. Single-nucleotide polymorphisms in the follicle-stimulating hormone subunit beta (FSHB) and follicle-stimulating hormone receptor (FSHR) genes have been described, with some of them affecting testicular volume and sperm output. The FSHR p.N680S and the FSHB -211G>T variants could be genetic markers to predict FSH response.

CONCLUSIONS

FSH may be helpful to increase sperm production in infertile men, even if the evidence to recommend the use of FSH in this setting is weak. Placebo-controlled clinical trials, considering the FSHB-FSHR haplotype, are needed to define the most effective dosage, the best treatment length, and the criteria to select candidate responder patients.

Follicle-stimulating Hormone (FSH) Action on Spermatogenesis: A Focus on Physiological and Therapeutic Roles

BACKGROUND

Human reproduction is regulated by the combined action of the follicle-stimulating hormone (FSH) and the luteinizing hormone (LH) on the gonads. Although FSH is largely used in female reproduction, in particular in women attending assisted reproductive techniques to stimulate multi-follicular growth, its efficacy in men with idiopathic infertility is not clearly demonstrated. Indeed, whether FSH administration improves fertility in patients with hypogonadotropic hypogonadism, the therapeutic benefit in men presenting alterations in sperm production despite normal FSH serum levels is still unclear. In the present review, we evaluate the potential pharmacological benefits of FSH administration in clinical practice.

METHODS

This is a narrative review, describing the FSH physiological role in spermatogenesis and its potential therapeutic action in men.

RESULTS

The FSH role on male fertility is reviewed starting from the physiological control of spermatogenesis, throughout its mechanism of action in Sertoli cells, the genetic regulation of its action on spermatogenesis, until the therapeutic options available to improve sperm production.

CONCLUSION

FSH administration in infertile men has potential benefits, although its action should be considered by evaluating its synergic action with testosterone, and well-controlled, powerful trials are required. Prospective studies and new compounds could be developed in the near future.

FSH for the Treatment of Male Infertility

Follicle-stimulating hormone (FSH) supports spermatogenesis acting via its receptor (FSHR), which activates trophic effects in gonadal Sertoli cells. These pathways are targeted by hormonal drugs used for clinical treatment of infertile men, mainly belonging to sub-groups defined as hypogonadotropic hypogonadism or idiopathic infertility. While, in the first case, fertility may be efficiently restored by specific treatments, such as pulsatile gonadotropin releasing hormone (GnRH) or choriogonadotropin (hCG) alone or in combination with FSH, less is known about the efficacy of FSH in supporting the treatment of male idiopathic infertility. This review focuses on the role of FSH in the clinical approach to male reproduction, addressing the state-of-the-art from the little data available and discussing the pharmacological evidence. New compounds, such as allosteric ligands, dually active, chimeric gonadotropins and immunoglobulins, may represent interesting avenues for future personalized, pharmacological approaches to male infertility.

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.

THE FREQUENCY OF FOLLICLE-STIMULATING HORMONE RECEPTOR 2039A>G GENE POLYMORPHISM AND THE RISK OF MALE INFERTILITY IN ALBANIAN POPULATION

The purpose of this study was to determine the prevalence of allele and genotype variants of the follicle-stimulating hormone receptor (FSHR) gene polymorphic region at position Asn680Ser in the Albanian male population and associate them with the clinical parameters of infertility. The study included 114 infertile men (mean age 35.04±5.85 years) stratified according to the level of spermatogenetic impairment (oligoasthenozoospermia, asthenozoospermia and normospermia) and 112 fertile men (mean age 36.44±7.05 years) with normal semen parameters. Genotyping of the FSHR gene at position 680 was performed by TaqMan genotyping assay. All the participants underwent semen analysis, and serum reproductive hormones (FSH, luteinizing hormone, prolactin and testosterone) were also measured. The FSHR Asn680Ser genotype frequencies were as follows: Asn/Ser 42%, Ser/Ser 33.9% and Asn/Asn 24.1% in the control group, and Asn/Ser 56.1%, Ser/Ser 22.8% and Asn/Asn 21.1% in the whole group of infertile men (χ2-test: P=0.08). There was no statistically significant correlation between serum hormone levels and semen characteristics or between fertility status and FSHR Asn680Ser gene variants in the control group and the group of infertile men. However, adjusted logistic regression analysis (age, body mass index, smoking and alcohol as covariates) revealed increased odds ratio for male infertility among heterozygous Asn/Ser genotype carriers associated with lower values of semen parameters (normal morphology, concentration, total sperm count and motility). In conclusion, our case-control study further confirmed previous reports on no significant association between the FSHR Asn680Ser polymorphisms and male infertility. Nevertheless, the data presented herein indicate that the Asn/Ser genotype may increase the risk of male infertility in Albanian population.

The influence of maternal androgen excess on the male reproductive axis

Prenatal androgen excess is suspected to contribute to the development of polycystic ovary syndrome (PCOS) in women. Evidence from preclinical female animal models links maternal androgen excess with the development of PCOS-like features and associated alterations in the neuronal network regulating the reproductive axis. There is some evidence suggesting that maternal androgen excess leads to similar reproductive axis disruptions in men, despite the critical role that androgens play in normal sexual differentiation. Here, the specific impact of maternal androgen excess on the male hypothalamic-pituitary-gonadal axis was investigated using a prenatal androgenization protocol in mice shown to model PCOS-like features in females. Reproductive phenotyping of prenatally androgenised male (PNAM) mice revealed no discernible impact of maternal androgen excess at any level of the reproductive axis. Luteinising hormone pulse characteristics, daily sperm production, plasma testosterone and anti-Müllerian hormone levels were not different in the male offspring of dams administered dihydrotestosterone (DHT) during late gestation compared to controls. Androgen receptor expression was quantified through the hypothalamus and identified as unchanged. Confocal imaging of gonadotropin-releasing hormone (GnRH) neurons revealed that in contrast with prenatally androgenised female mice, PNAM mice exhibited no differences in the density of putative GABAergic innervation compared to controls. These data indicate that a maternal androgen environment capable of inducing reproductive dysfunction in female offspring has no evident impact on the reproductive axis of male littermates in adulthood.

Fertility management of Klinefelter syndrome

Introduction: Klinefelter syndrome (KS) represents the most common chromosomal abnormality in the general population, and one of the most common genetic etiologies of nonobstructive azoospermia (NOA) and in severe oligospermia. Once considered untreatable, men with KS and NOA now have a variety of treatment options to obtain paternity.Areas covered: The cornerstone of treatment for both KS and NOA patients remains the surgical retrieval of viable sperm, which can be used for intracytoplasmic sperm injection to obtain pregnancy. Although the field has advanced significantly since the early 1990s, approximately half of men with KS will ultimately fail fertility treatments. Presented is a critical review of the available evidence that has attempted to identify predictive factors for successful sperm recovery. To optimize surgical success, a variety of treatment modalities have also been suggested and evaluated, including hormonal manipulation and timing of retrieval.Expert opinion: Individuals with KS have a relatively good prognosis for sperm recovery compared to other men with idiopathic NOA. Surgical success is heavily dependent upon surgical technique and the experience of the andrology/embryology team tasked with the identification and use of testicular sperm.

Dissecting the syndrome of schizophrenia: Associations between symptomatology and hormone levels in women with schizophrenia

Despite many studies implicating reproductive hormones in the development and outcome of schizophrenia, few have characterised the association between symptomatology and hormonal trajectories. To understand the influence of hormones on schizophrenia symptoms, serum steroids (estradiol, progesterone, follicular stimulating hormone (FSH), luteinising hormone (LH), and dehydroepiandrosterone (DHEA)) and psychopathology (The positive-and-negative-syndrome-scale(PANSS)) and depression (Montgomery-Asberg-Depression-Rating Scale(MADRS)) were collected across 12-weeks in 45 women (mean age 46) diagnosed with schizophrenia. To account for potential heterogeneity, Group-based-trajectory-modelling of psychopathology was used to identify distinct subgroups of individuals following a similar pattern of association between symptom score and hormone levels over-time. Two trajectories were identified for PANSS: one subgroup with lower symptom severity was associated with FSH, DHEA, LH, and another high severity subgroup associated with LH. Two trajectories were identified for MADRS: 'depressed' (associated with FSH), and non-depressed. The result delineates subpopulations with unique psychopathology and hormone associations that support the hypothesis that reproductive hormones play a role in the pathophysiology of schizophrenia, and that heterogeneity may exist in hormonal sensitivities in the schizophrenia population. Stratification of subjects according to biological phenotype may help improve existing treatments through personalised-medicine strategies. The endocrine system may be one such biological mechanism to continue dissecting the syndrome.

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.

FSHB -211 G>T Polymorphism as Predictor for TESE Success in Patients With Unexplained Azoospermia

CONTEXT

Testicular sperm extraction (TESE) followed by assisted reproductive techniques often remains the only therapeutic option for men with azoospermia due to spermatogenic failure. Reproductive parameters, such as gonadotropin levels and testicular volume or histopathology, contribute to the prediction of sperm retrieval rate (SRR) in TESE. However, there is an eminent lack of noninvasive predictive factors for TESE outcome.

OBJECTIVE

To clarify the impact of three common genetic variants affecting FSH and its cognate receptor on testicular histopathology patterns and SRR in TESE.

DESIGN

We evaluated the association of the single-nucleotide polymorphisms (SNP) FSHB -211G>T (rs10835638), FSHR -29G>A (rs1394205), and FSHR c.2039A>G (rs6166) with testicular histopathology and SRR in patients with azoospermia.

SETTING

Tertiary referral center for andrology.

PATIENTS OR OTHER PARTICIPANTS

Men (n = 1075) with azoospermia who underwent TESE (grouped by clinical pathologies).

INTERVENTION(S)

All participants underwent TESE.

MAIN OUTCOME MEASURE(S)

Testicular histopathology, SRR, and reproductive hormone levels.

RESULTS

FSHB -211G>T was significantly associated with reduced chances of sperm retrieval in patients with unexplained azoospermia. Indicating an additional mechanism, the association of the SNP with SSR could not be solely attributed to decreased FSH levels.

CONCLUSION

A common genetic factor was significantly associated with SRR in TESE. In perspective, a calculator or score including the noninvasive parameters FSH level, testicular volume, and FSHB haplotype should be considered to estimate the chances for sperm retrieval in men with azoospermia.

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.

Pluripotent Very Small Embryonic-Like Stem Cells in Adult Testes - An Alternate Premise to Explain Testicular Germ Cell Tumors

Developmental exposure to endocrine disruptors has resulted in the increased incidence of infertility and testicular germ cell tumors (T2GCT) in young men residing in developed countries. Unlike T1GCT (infants and young children) and T3GCT (aged men), T2GCT arise from CIS/GCNIS that develops from pre-CIS. Pre-CIS represents undifferentiated, growth-arrested gonocytes that persist in fetal testes due to endocrine disruption. However, whether pre-CIS truly exist, do CIS develop into T2GCT, why no CIS in T1GCT/T3GCT, why germ cell tumors (GCT) also occur along midline at extra-gonadal sites, why T1GCT show partial erasure and T2GCT show complete erasure of genomic imprints are open questions that are awaiting answers. We propose that rather than pre-CIS, pluripotent, very small embryonic-like stem cells (VSELs) get affected by exposure to endocrine disruption. Since VSELs are developmentally equivalent to primordial germ cells (PGCs), T2GCT cells show complete erasure of genomic imprints and CIS represents growth-arrested clonally expanding stem/progenitor cells. PGCs/VSELs migrate along the midline to various organs and this explains why GCT occur along the midline, T1GCT show partial erasure of imprints as they develop from migrating PGCs. T3GCT possibly reflects effects of aging due to compromised differentiation and expansion of pre-meiotic spermatocytes. Absent spermatogenesis in pre-pubertal and aged testes explains absence of CIS in T1GCT and T3GCT. Endocrine disruptors possibly alter epigenetic state of VSELs and thus rather than maintaining normal tissue homeostasis, VSELs undergo increased proliferation and compromised differentiation resulting in reduced sperm count, infertility and TGCT. This newly emerging understanding offers alternate premise to explain TGCT and warrants further exploration.

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.

Effects of a Polymorphism in the Promoter Region of the Follicle-Stimulating Hormone Subunit Beta (FSHB) Gene on Female Reproductive Outcomes

BACKGROUND

Follicle-stimulating hormone (FSH) is essential to the hypothalamic-pituitary-gonadal axis, playing a key role in human reproduction. It is a heterodimer comprised of a hormone-specific β-chain (FSH-β) that is associated with an α-chain. It exerts its biological activities by binding to the FSH receptor (FSHR). The β-subunit, which is encoded by the FSHB gene, is responsible for ensuring binding specificity to the FSHR. There is a promoter polymorphism in this gene, c.-211G>T (rs10835638), upstream of the transcription start site; and in vitro studies have reported that the T allele decreases FSHB transcription in gonadotrophic cells.

AIMS

Investigate the possible effects of the FSHB c.-211G/T polymorphism on hormonal profile and in in vitro fertilization (IVF)/intracytoplasmic sperm injection outcomes in normoovulatory Brazilian women.

METHODS

A cross-sectional study of 140 women (median age = 33 years [CI: 32-34]) with infertility mainly caused by male (n = 85) or tuboperitoneal (n = 55) factors. In this study we evaluated FSH, estradiol, luteinizing hormone (LH), progesterone, prolactin and anti-Mullerian hormone levels, and antral follicle counting (AFC). Genotyping was performed using the TaqMan real-time polymerase chain reaction methodology.

RESULTS

The wild-type allele G was found in 86.4% and the polymorphic allele T in 13.6% of the women respectively. The TT genotype was not found in any women. Women carrying the GT genotype had a poorer response more frequently to controlled ovarian hyperstimulation when compared to individuals with the GG genotype (47.4% vs. 26.5%, p = 0.010), higher LH levels (3.1 IU/mL vs. 2.4 IU/mL, p = <0.001), lower AFC (8.0 vs. 10.0, p = 0.03), oocytes retrieved (3.0 vs. 5.0, p = 0.03), MII (3.0 vs. 4.0, p = 0.02), and embryos (2.0 vs. 3.0, p = 0.02). Despite these findings, no difference was observed in pregnancy rate.

CONCLUSION

Our findings suggest that the FSHB c.-211G/T polymorphism may modestly alter some aspects of the female reproductive system, but they are not associated with significantly different IVF outcomes.

Testosterone and FSH modulate Sertoli cell extracellular secretion: Proteomic analysis

Spermatogenesis is a highly complicated biological process that occurs in the epithelium of the seminiferous tubules. It is regulated by a complex network of endocrine and paracrine factors and by juxtacrine testicular cross-talk. Sertoli cells (SC) play a key role in spermatogenesis due to their production of trophic, differentiation and immune-modulating factors, but many of the molecular pathways of SC action remain controversial and unclear. Over the last two decades, research has focused on extracellular vesicles as an important mechanism of intercellular communication. The aim of this study was to investigate the presence of extracellular vesicles (EVs) in SC and the modulation of their content in SC after FSH and testosterone stimulation. Highly purified porcine pre-pubertal Sertoli cells were isolated according to previously established methods. After 48 h of culture with FSH or FSH + testosterone stimulation, we identified sertolian EVs containing specific mRNAs. Proteomic analysis of EVs content identified 29 proteins under non-stimulatory conditions, most of which were related to receptor binding activity. FSH stimulation induced increases in inhibin-alpha, inhibin-beta, plakoglobin, haptoglobin, D-3-phosphoglycerate dehydrogenase and sodium/potassium-transporting ATPase in sertolian EVs. Testosterone stimulation enhanced the abundance of inhibin-alpha, inhibin-beta, tissue-type plasminogen activator, epidermal growth factor-like protein 8, elongating factor 1-gamma and D-3-phosphoglycerate dehydrogenase. These results are likely to help determine the unknown molecular secretion of Sertoli cells.

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.

Pharmacogenetics of G-protein-coupled receptors variants: FSH receptor and infertility treatment

Infertility treatment may represent a paradigmatic example of precision medicine. Follicle-stimulating hormone (FSH) has been proposed as a valuable therapeutic option both in males and in females, even if a standardized approach is far to be established. To date, several genetic mutations as well as polymorphisms have been demonstrated to significantly affect the pathophysiology of FSH-FSH receptor (FSHR) interaction, although the underlying molecular mechanisms remain unclear. This review aims to highlight possible aspects of FSH therapy that could benefit from a pharmacogenetic approach, providing an up-to-date overview of the variability of the response to FSH treatment in both sexes. Specific sections are dedicated to the clinical use of FSH in infertility and how FSHR polymorphisms may affect the therapeutic endpoints.

Relevance of testicular histopathology on prediction of sperm retrieval rates in case of non-obstructive and obstructive azoospermia

Introduction:

The aim of our research was to establish the relevance of testicular histopathology on sperm retrieval after testicular sperm extraction in patients with non-obstructive azoospermia and in patients with obstructive azoospermia, who already underwent a previous failure testicular fine needle aspiration.

Methods:

We evaluated a total of 82 azoospermic men, underwent testicular sperm extraction, referring to the Assisted Reproductive Technology Centre of the University of Florence, Italy between January 2008 and March 2017. A general and genital physical examination, scrotal and trans-rectal ultrasound, semen analysis, hormone measurements, including follicle-stimulating hormone, luteinizing hormone and total testosterone, were collected.

Results:

Successful sperm retrieval was obtained in 36 men of total (43.9%). Successful sperm retrieval was 29.5% in non-obstructive azoospermia patients, while men with obstructive azoospermia, who, underwent a previous failure testicular fine needle aspiration, had sperm retrieval in 86% of cases. Mean luteinizing hormone was 6.55 IU/L, total testosterone 4.70 ng/mL, right testicular volume 13.7 mL and left testicular volume 13.6 mL. Mean Follicle-stimulating hormone was 13.45 IU/L in patients with negative sperm retrieval and 8.18 IU/L in men with successful sperm retrieval. According to histology, 20.7% had normal spermatogenesis, 35.3% hypospermatogenesis, 35.3% maturation arrest and 8.5% Sertoli cell-only syndrome. Successful sperm retrieval was 88.2% in patients with normal spermatogenesis, 24.1% in the maturation arrest group and 48.27% in patients with hypospermatogenesis, while negative sperm retrieval was reported in Sertoli cell-only syndrome patients. Seven cases with maturation arrest showed a successful sperm retrieval.

Conclusion:

Testicular histopathology after testicular sperm extraction offers important information on prediction of sperm retrieval and can guide the surgeon in choosing the more suitable therapeutic practice.

Effects of Vitamin D Supplementation on Semen Quality, Reproductive Hormones, and Live Birth Rate: A Randomized Clinical Trial

CONTEXT

Results of animal models and cross-sectional cohort studies have suggested a beneficial role for vitamin D in male reproduction.

OBJECTIVE

Determine the effect of vitamin D and calcium supplementation on semen quality in infertile men with serum 25-hydroxyvitamin-D (25OHD) levels ≤50 nmol/L.

DESIGN

A single-center, triple-blinded, randomized clinical trial.

PARTICIPANTS

A total of 1427 infertile men were screened to include 330; 1002 men did not meet inclusion criteria and 95 did not wish to participate.

INTERVENTION

The active group received cholecalciferol 300,000 IU initially, then 1400 IU cholecalciferol and 500 mg of calcium daily for 150 days; the other group received placebo.

RESULTS

Serum concentrations of 25OHD and 1,25-dihydroxyvitamin D3 were significantly higher in men in the treatment group compared with the placebo group. Vitamin D supplementation was not associated with changes in semen parameters, although spontaneous pregnancies tended to be higher in couples in which the man was in the treatment group [7.3% vs 2.4%, Δ5.0% (-0.6%; 10.5%)]. Vitamin D treatment in a subgroup of oligozoospermic men increased the chance for a live birth compared with placebo [35.6% vs 18.3%, Δ17.3% (1.6%; 32.9%)]. Moreover, serum inhibin B levels were higher in men deficient in vitamin D who were randomly assigned to receive high-dose vitamin D [193 pg/mL vs 143 pg/mL, Δ49 pg/mL (8; 91 pg/mL)]; however, the increase in sperm concentration was not significantly higher than in the placebo group (P = 0.07).

CONCLUSION

High-dose vitamin D supplementation did not improve semen quality in vitamin D-insufficient infertile men. The positive impact of vitamin D supplementation on live birth rate and serum inhibin B in oligozoospermic and vitamin D-deficient men may be of clinical importance and warrant verification by others.

Recombinant FSH Improves Sperm DNA Damage in Male Infertility: A Phase II Clinical Trial

Background and objectives: Male infertility is a global health dilemma and Follicle-Stimulating Hormone (FSH) administration has shown promising results. Several studies showed that infertile men with normal semen parameters have low levels of DNA damage while infertile men with abnormal semen parameters have more damage at the DNA level. Sperm DNA damage may affect the reproductive outcome and has been associated with failure in the achievement of competent embryos and pregnancy fulfillment. The aim of this study was to evaluate whether the administration of recombinant FSH (Gonal-f® PEN 900 IU) could improve sperm DNA fragmentation in men with infertility. The secondary endpoints of this study were to evaluate the FSH effects on sperm parameters and hormonal assets. Methods: A longitudinal, prospective, multicenter, open-label clinical trial was carried out. Infertile couples were recruited from six Italian Reproductive Medical Centers and 115 infertile men were enrolled for this study. All participants were treated with subcutaneous injections of Gonal-f® 150 IU every other day, within a 3 month-time frame. The semen samples were examined in accordance to the 2010 World Health Organization criteria. Sperm DNA Fragmentation (DFI) was determined by fluorescence microscopy using terminal deoxynucleotidyl transferase-mediated d-UTP Nick-end Labeling (TUNEL) assay. Statistical analysis was performed using both the t-test for paired samples and the Wilcoxon signed-rank test. Results: FSH administration improved DFI in 67% of patients, with an average decrease of 35.4% compared to the baseline. This improvement is more evident in men with basal DFI lower than 17% and in those with FSH basal levels between 2.16 and 4.27 IU/L. In addition, FSH enhanced the gonadal function, increasing the hormones AMH and Inhibin B and semen parameters. Limitation of these results are represented by the absence of a placebo group and of FSHR genotype stratification sub-analysis. Conclusion: Recombinant FSH 150 IU is well tolerated and effective in eliciting a significant DFI reduction as well as in improving gonadal function.

TRIAL REGISTRATION

EUDRACT Number 2010-020196-23. Registred 14 April 2011.

Does a male polycystic ovarian syndrome equivalent exist?

The occurrence of a genetic background in the etiology of polycystic ovarian syndrome (PCOS) represents the rational basis to postulate the existence of a male PCOS equivalent. Hormonal and metabolic abnormalities have been described in male relatives of women with PCOS. These males also have a higher prevalence of early onset (<35 years) androgenetic alopecia (AGA). Hence, this feature has been proposed as a clinical sign of the male PCOS equivalent. Clinical evidence has shown that men with early onset AGA have hormonal and metabolic abnormalities. Large cohort studies have clearly shown a higher prevalence of type II diabetes mellitus (DM II) and cardiovascular diseases (CVDs) in elderly men with early onset AGA. In addition, prostate cancer, benign prostate hyperplasia (BPH) and prostatitis have been described. These findings support the existence of the male PCOS equivalent, which may represent an endocrine syndrome with a metabolic background, and might predispose to the development of DM II, CVDs, prostate cancer, BPH and prostatitis later in life. Its acknowledgment would be helpful for the prevention of these long-term complications.

The susceptibility of FSHB -211G > T and FSHR G-29A, 919A > G, 2039A > G polymorphisms to men infertility: an association study and meta-analysis

BACKGROUND

Male infertility is a complex disorder caused by genetic, developmental, endocrine, or environmental factors as well as unknown etiology. Polymorphisms in the follicle stimulating hormone beta subunit (FSHB) (rs10835638, c.-211G > T) and follicle stimulating hormone receptor (FSHR) (rs1394205, c.-29G > A; rs6165, c.919A > G; rs6166, c.2039 A > G) genes might disturb normal spermatogenesis and affect male reproductive ability.

METHODS

To further ascertain the aforementioned effects, we conducted a case-control study of 255 infertile men and 340 fertile controls from South China using the Mass ARRAY method, which was analyzed by the t-tests and logistic regression analysis using SPSS for Windows 14.0. In addition, a meta-analysis was performed by combining our results with previous reports using STATA 12.0.

RESULTS

In the FSHB or FSHR gene single nucleotide polymorphism (SNP) evaluation, no statistically-significant difference was found in the frequency of allelic variants or in genotype distribution between cases and controls. However, a significant association for the comparison of GAA (P: 0.022, OR: 0.63, 95%CI: 0.43-0.94) was seen between the oligozoospermia and controls in haplotype analysis of rs1394205/rs6165/rs6166. In the meta-analysis, rs6165G allele and rs6166 GG genotype were associated with increased risk of the male infertility.

CONCLUSIONS

This study suggested that FSHR GAA haplotype would exert protective effects against male sterility, which indicated that the combination of three SNP genotypes of FSHR was predicted to have a much stronger impact than either one alone. Then in the meta-analysis, a significant association was seen between FSHR rs6165, rs6166 polymorphisms and male infertility. In terms of male infertility with multifactorial etiology, further studies with larger sample sizes and different ethnic backgrounds or other risk factors are warranted to clarify the potential role of FSHB and FSHR polymorphisms in the pathogenesis of male infertility.

[Rational diagnosis and treatment of male infertility]

Male infertility can be diagnosed by evaluation of the (female and) male history with respect to risk factors, and includes scrotal sonography, hormone and semen measurements. In severe male factor infertility, genetic testing is indicated. Treatment options vary between preventive, medical or surgical strategies depending on the underlying diagnosis. Assisted reproductive techniques may be applied as a consequence of the couple's infertility profile.

Association of follicle-stimulating hormone receptor single nucleotide polymorphisms with fertility in Greek men

BACKGROUND AND OBJECTIVE

Although several epidemiological studies have been conducted, the impact of follicle-stimulating hormone receptor (FSHR) polymorphisms on male infertility remains unclear. The aim of this study was to investigate the prevalence of specific FSHR single nucleotide polymorphisms (SNPs) in the Greek population and associate the latter with the clinical phenotype.

PATIENTS AND METHODS

We enrolled 96 subjects: men with idiopathic non-obstructive azoospermia (n = 78) were compared with a control group of fertile men (n = 18) for SNPs in FSHR positions c.-29, c.566, c.919, and c.2039. The SNP in position 566 (c.566C > T) was assessed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) and the other three SNPs (c.-29G > A, c.919A > G, c.2039A > G) with single-strand conformation polymorphism (SSCP); all of them were validated with DNA sequence.

RESULTS

No polymorphisms were detected in positions c.-29 and c.919 (c.-29G > A, c.919A > G). The heterozygous SNP (AG) at position 2039 was associated with different size of the right testis (p = 0.008). There was no association between the c.566C > T SNPs polymorphism and hormonal or semen parameters. The combination SNP 2039 AA with 566 CT revealed significant association with FSH and LH concentrations.

CONCLUSIONS

FSHR SNPs at positions c.-29, c.566, c.919, and c.2039 (c.-29G > A, c.566C > T, c.919A > G, c.2039A > G) do not appear to play specific roles in male infertility. Larger studies are needed to confirm these results.

Genetic Variation of Follicle-Stimulating Hormone Action Is Associated With Age at Testicular Growth in Boys

CONTEXT

Although genetic factors play a pivotal role in male pubertal timing, genome-wide association studies have identified only a few loci. Genetic variation of follicle-stimulating hormone (FSH) action affects adult reproductive parameters and female pubertal timing.

OBJECTIVE

To investigate whether genetic variation affecting FSH action is associated with onset of puberty in boys.

DESIGN

Cross-sectional and longitudinal study of two cohorts of healthy boys.

SETTING

This was a population-based study.

PATIENTS OR OTHER PARTICIPANTS

Danish (n = 1130) and Chilean (n = 424) boys were followed through puberty and genotyped for FSHB c.-211G>T, FSHR c.-29A>G, and FSHR c.2039G>A.

MAIN OUTCOME MEASURES

Clinical pubertal staging including orchidometry, anthropometry, and serum gonadotropin levels.

RESULTS

Although the cohorts differed markedly (e.g., body composition and genotype frequencies), genetic variation affecting FSH production (FSHB c.-211G>T) was associated with age at pubertal onset, as assessed by testicular enlargement, in both cohorts. The effect appeared further modified by coexistence of genetic variation affecting FSH sensitivity (FSHR c.-29G>A): After correcting for body mass index (BMI), boys with a ligand-receptor variant combination resulting in weak FSH action (i.e., FSHB c.-211GT/TT and FSHR c.-29AA) entered puberty 0.64 years [95% confidence interval (CI), 0.12 to 1.17 years; Denmark] and 0.94 years (95% CI, 0.00 to 1.88 years; Chile) later than boys with the most effective FSH action. Effects explained 1.7% (Denmark) and 1.5% (Chile) of the variance. In addition, BMI z score was negatively associated with pubertal timing (β = -0.35 years in both cohorts), explaining 17.2% (Denmark) and 7.2% (Chile) of the variance.

CONCLUSION

In two ethnically distinct populations, we independently identified an association of two genetic loci with male pubertal timing.