Genetic Regulation of Physiological Reproductive Lifespan and Female Fertility.

There is substantial genetic variation for common traits associated with reproductive lifespan and for common diseases influencing female fertility. Progress in high-throughput sequencing and genome-wide association studies (GWAS) have transformed our understanding of common genetic risk factors for complex traits and diseases influencing reproductive lifespan and fertility. The data emerging from GWAS demonstrate the utility of genetics to explain epidemiological observations, revealing shared biological pathways linking puberty timing, fertility, reproductive ageing and health outcomes. The observations also identify unique genetic risk factors specific to different reproductive diseases impacting on female fertility. Sequencing in patients with primary ovarian insufficiency (POI) have identified mutations in a large number of genes while GWAS have revealed shared genetic risk factors for POI and ovarian ageing. Studies on age at menopause implicate DNA damage/repair genes with implications for follicle health and ageing. In addition to the discovery of individual genes and pathways, the increasingly powerful studies on common genetic risk factors help interpret the underlying relationships and direction of causation in the regulation of reproductive lifespan, fertility and related traits.

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.

High-level expression of biologically active human follicle stimulating hormone in the Chinese hamster ovary cell line by a pair of tricistronic and monocistronic vectors.

Recombinant human follicle stimulating hormone (FSH), produced in Chinese hamster ovary (CHO) cells, is widely used for treatment of fertility disorders and is subject to biosimilars development. Cell lines with high specific productivities may simplify the FSH production process. Here, we used our previously established expression system based on vector p1.1 to create new cell lines secreting heterodimeric FSH protein. To this end, we linked open reading frames of both FSH subunits by the wild-type internal ribosome entry site from the encephalomyocarditis virus (EMCV IRES). Intact and double-negative for the dihydrofolate reductase CHO cells were stably transfected by the FSH-coding plasmids. Stably transfected intact cells showed higher level of the FSH secretion and were utilized for subsequent methotrexate-driven transgene amplification, which doubled their productivity. The excess of the free α-subunit was corrected by transfecting the cells by the additional p1.1-based plasmid encoding the ß-subunit of the FSH. Clonal cell lines obtained secreted mostly the heterodimeric FSH and possessed specific productivities up to 12.3±1.7 pg/cell/day. Candidate clonal cell line C-P1.3-FSH-G4 maintained a constant specific productivity for at least 2 months of culturing without the section pressure. The resulting FSH protein conformed to the international pharmaceutical quality criteria as evidenced by the receptor binding kinetics, distribution pattern of hormone isoforms and biological activity. In conclusion, our expression system offers a simple and cost-effective approach to production of FSH.

High FSH dosing is associated with reduced live birth rate in fresh but not subsequent frozen embryo transfers.

STUDY QUESTION: Do live birth rates (LBRs) differ between fresh embryo transfer (fresh ET) cycles and their subsequent paired frozen ET (FET) cycles, when comparing cycles based on the total FSH dose used during the fresh cycle? SUMMARY ANSWER: When compared to the paired frozen embryo transfer cycles, the LBR in the fresh cycle of the highest total FSH dose group (>2500 IU) was reduced by 38%. WHAT IS KNOWN ALREADY: There may be a negative association with high gonadotropin doses and LBR after fresh ET. It is unknown whether a similar effect is seen in FET cycles, which are done with increasing frequency. STUDY DESIGN, SIZE, DURATION: In this retrospective observational paired study, we studied IVF cycles between 10 January 2005 and 19 September 2015, for all patients who underwent a fresh, autologous IVF cycle that resulted in at least one fresh ET and at least one FET. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study included 862 women, treated in our academic medical centre, who underwent 935 fresh ET and 1274 FET cycles. Cycles were allocated into three groups based on the total gonadotropin dose they received during their fresh IVF cycle: Group 1 (≤1800 IU FSH), Group 2 (1801-2500 IU), Group 3 (>2500 IU). The primary outcome was LBR after fresh ET and its subsequent paired FET(s), as well as LBR among fresh ETs and FETs as independent samples, based on the total FSH dose used. Implantation rates obtained from fresh and FET cycles were also compared. MAIN RESULTS AND THE ROLE OF CHANCE: The unadjusted fresh LBR was similar between Groups 1 and 2 (46.0% [95% CI: 40.4-51.6] versus 43.8% [38.3-49.4], respectively) but significantly lower in Group 3 (34.4% [29.5-39.8]). The unadjusted frozen transfer LBR was similar among all groups (51.4% [46.7-56.1] versus 46.3% [41.3-51.4] versus 47.5% [42.5-52.4], respectively). When logistic regression analysis with generalized estimating equations was used to control for confounders, the adjusted LBR was found to be similar between the groups both for fresh (odds ratio [OR] = 0.97 [95% CI: 0.61-1.56] Group 2 versus Group 1, OR = 0.69 [0.39-1.21] Group 3 versus Group 1) and FET cycles (OR = 0.87 [0.58-1.31] Group 2 versus Group 1, OR = 0.95 [0.58-1.55] Group 3 versus Group 1). However, for Group 3, the adjusted fresh LBR was 38% lower than its subsequent frozen transfer LBR (OR = 0.62 [0.41-0.93]); this was a statistically significant difference, which was not observed in Group 1 (OR = 0.85 [0.56-1.27]) or Group 2 (OR = 0.95 [0.64-1.41]). LIMITATIONS, REASONS FOR CAUTION: This study is a retrospective cohort, with all of the associated inherent biases. WIDER IMPLICATIONS OF THE FINDINGS: Fresh LBR is negatively impacted by a high dose of total FSH used, as compared to the LBR in subsequent paired FET cycles. Frozen transfer LBR seems unaffected by the total FSH dose used in the fresh cycle, suggesting that the endometrium may be adversely affected, probably indirectly, by high dose gonadotropin use in the fresh IVF cycle only. STUDY FUNDING/COMPETING INTEREST(S): No funding source was used for the completion of this project. There are no conflicts of interest.

Subfertility in androgen-insensitive female mice is rescued by transgenic FSH.

Androgens synergise with FSH in female reproduction but the nature of their interaction in ovarian function and fertility is not clear. In the present study, we investigated this interaction, notably whether higher endogenous FSH can overcome defective androgen actions in androgen receptor (AR)-knockout (ARKO) mice. We generated and investigated the reproductive function of mutant mice exhibiting AR resistance with or without expression of human transgenic FSH (Tg-FSH). On the background of inactivated AR signalling, which alone resulted in irregular oestrous cycles and reduced pups per litter, ovulation rates and antral follicle health, Tg-FSH expression restored follicle health, ovulation rates and litter size to wild-type levels. However, Tg-FSH was only able to partially rectify the abnormal oestrous cycles observed in ARKO females. Hence, elevated endogenous FSH rescued the intraovarian defects, and partially rescued the extraovarian defects due to androgen insensitivity. In addition, the observed increase in litter size in Tg-FSH females was not observed in the presence of AR signalling inactivation. In summary, the findings of the present study reveal that FSH can rescue impaired female fertility and ovarian function due to androgen insensitivity in female ARKO mice by maintaining follicle health and ovulation rates, and thereby optimal female fertility.

[Relationship between the FSHR Thr307Ala-Asn680Ser gene polymorphism and male infertility: A meta-analysis].

OBJECTIVE: To assess the association of the FSHR Thr307Ala-Asn680Ser gene polymorphism with male infertility. METHODS: We searched Pubmed, EMBASE, Web of Science, CNKI, and WANFANG databases for literature on the correlation of the FSHR Thr307Ala-Asn680Ser gene polymorphism with male infertility published from 2005 to the present time. According to the inclusion criteria, we included 12 epidemiological case-control studies and subjected them to a comprehensive analysis with the Stata11.0 software. RESULTS: A total of 2 893 male infertility patients and 3 312 controls were involved in the 12 studies. The Thr307Ala (rs6165) gene polymorphism was shown to be a risk factor for male infertility among the three comparison models (homozygous comparison model, hybrid comparison model and dominant comparison model), with the pooled odds ratios (OR) of 1.26 (95% CI: 1.03－1.54, P = 0.023), 1.18 (95% CI: 1.03－1.36, P = 0.018), and 1.20 (95% CI: 1.05－1.37, P = 0.006), respectively. And the Asn680Ser(rs6166) polymorphism was a risk factor for male infertility in the homozygous comparison and recessive comparison models, with the pooled ORs of 1.24, (95% CI: 1.05－1.45, P = 0.009) and 1.20 (95% CI: 1.04－1.39, P = 0.013), respectively. Layered meta-analysis showed that in the homozygous comparison model, the Thr307Ala-Asn680Ser polymorphism is a risk factor for male infertility in the white population, with the OR of 1.37 (95% CI: 1.03－1.82, P = 0.003) and 1.21 (95% CI: 1.00－1.47, P = 0.048), respectively. CONCLUSIONS: In the homozygous model (GG vs AA), the FSHRThr307Ala-Asn680Ser gene polymorphism might be a protective factor against male infertility.

FSH-FSHR3-stem cells in ovary surface epithelium: basis for adult ovarian biology, failure, aging, and cancer.

Despite extensive research, genetic basis of premature ovarian failure (POF) and ovarian cancer still remains elusive. It is indeed paradoxical that scientists searched for mutations in FSH receptor (FSHR) expressed on granulosa cells, whereas more than 90% of cancers arise in ovary surface epithelium (OSE). Two distinct populations of stem cells including very small embryonic-like stem cells (VSELs) and ovarian stem cells (OSCs) exist in OSE, are responsible for neo-oogenesis and primordial follicle assembly in adult life, and are modulated by FSH via its alternatively spliced receptor variant FSHR3 (growth factor type 1 receptor acting via calcium signaling and the ERK/MAPK pathway). Any defect in FSH-FSHR3-stem cell interaction in OSE may affect folliculogenesis and thus result in POF. Ovarian aging is associated with a compromised microenvironment that does not support stem cell differentiation into oocytes and further folliculogenesis. FSH exerts a mitogenic effect on OSE and elevated FSH levels associated with advanced age may provide a continuous trigger for stem cells to proliferate resulting in cancer, thus supporting gonadotropin theory for ovarian cancer. Present review is an attempt to put adult ovarian biology, POF, aging, and cancer in the perspective of FSH-FSHR3-stem cell network that functions in OSE. This hypothesis is further supported by the recent understanding that: i) cancer is a stem cell disease and OSE is the niche for ovarian cancer stem cells; ii) ovarian OCT4-positive stem cells are regulated by FSH; and iii) OCT4 along with LIN28 and BMP4 are highly expressed in ovarian cancers.

Human steroidogenesis: implications for controlled ovarian stimulation with exogenous gonadotropins.

In the menstrual cycle, the mid-cycle surge of gonadotropins (both luteinising hormone [LH] and follicle-stimulating hormone [FSH]) signals the initiation of the periovulatory interval, during which the follicle augments progesterone production and begins to luteinise, ultimately leading to the rupture of the follicle wall and the release of an oocyte. The administration of gonadotropins in controlled ovarian stimulation (COS) leads to supraphysiological steroid concentrations of a very different profile compared with those seen during natural cycles. It has been suggested that these high steroid concentrations cause alterations in endometrial development, affecting oocyte viability in assisted reproductive technology. Furthermore, it has been proposed that elevated progesterone levels have a negative effect on the reproductive outcome of COS. This may arise from an asynchrony between embryo stage and endometrium status at the window of implantation. The regulation of progesterone production by the developing follicles during COS is a complicated interplay of hormonal systems involving the theca and granulosa cells, and the effect of the actions of both LH and FSH. The present paper reviews current knowledge of the regulation of progesterone in the human ovary during the follicular phase and highlights areas where knowledge remains limited. In this review, we provide in-depth information outlining the regulation and function of gonadotropins in the complicated area of steroidogenesis. Based on current evidence, it is not clear whether the high levels of progesterone produced during COS have detrimental effects on fertility.

Phase IV, open-label, randomized study of low-dose recombinant human follicle-stimulating hormone protocols for ovulation induction.

BACKGROUND: This Phase IV, open-label, multicentre, randomized study (MEnTOR) compared two low-dose recombinant human follicle-stimulating hormone (r-hFSH) protocols for ovulation induction. METHODS: This study was conducted in six Middle Eastern countries between March 2009 and March 2011. Eligible women (18-37 years), with World Health Organization Group II anovulatory infertility, were randomized to receive r-hFSH (starting daily dose: 75 IU) as a chronic low-dose (CLD) (37.5 IU dose increase on Day 14) or low-dose (LD) (37.5 IU dose increase on Day 7) protocol if no follicles were ≥ 10 mm. The maximum r-hFSH daily dose permitted was 225 IU/day. The total length of ovarian stimulation could not exceed 35 days, unless ultrasound assessment suggested imminent follicular growth and maturation. Patients underwent only one treatment cycle. Primary endpoint: incidence of mono-follicular development. Secondary endpoints included: stimulation duration and rates of bi-follicular development; human chorionic gonadotrophin administration rate; clinical pregnancy; and cycle cancellation (owing to inadequate response). Adverse events (AEs) were recorded. The primary efficacy analysis was performed using data from all patients who received at least one dose of correct study medication, had at least one efficacy assessment, and no protocol violations at treatment start (CLD group, n=122; LD group, n=125). RESULTS: Mono-follicular development rates (primary endpoint) were similar in both groups (CLD: 56.6% [69/122] versus LD: 55.2% [69/125], p=0.93; primary efficacy analysis population). Similarly, there were no significant differences between groups in bi-follicular development, clinical pregnancy or cycle cancellation (inadequate response) rates. In patients who received human chorionic gonadotrophin injections, the mean duration of stimulation was 13.7 days in the CLD group and 12.9 days in the LD group. Clinical pregnancy rates for those patients who received an hCG injection were similar in both groups (CLD: 20.2% [19/94] versus LD: 19.8% [18/91], p=0.94; primary efficacy analysis population). Most AEs were mild in severity. Only one case of ovarian hyperstimulation syndrome was reported (mild; CLD group). CONCLUSIONS: Efficacy and safety outcomes were similar for the two protocols.

Different pharmacokinetic and pharmacodynamic properties of recombinant follicle-stimulating hormone (rFSH) derived from a human cell line compared with rFSH from a non-human cell line.

Pharmacokinetic and pharmacodynamic properties of a novel recombinant follicle-stimulating hormone (rFSH) preparation (FE 999049), expressed by a human cell line (PER.C6), was compared with an rFSH preparation (follitropin α) expressed by a Chinese hamster ovary (CHO) cell line in healthy pituitary-suppressed women. Following single intravenous administration of 225 IU (Steelman-Pohley assay), the clearance was lower, 0.31 versus 0.44 L/h, for FE 999049 than for follitropin α. Likewise, the apparent clearance after repeated daily subcutaneous administrations was lower, 0.58 versus 0.99 L/h, and AUC and C(max) higher, 1.7- and 1.6-fold. The absolute bioavailability after a single subcutaneous dose of 450 IU was similar for both preparations, 60-65%. After repeated subcutaneous administration the elimination half-life was approximately 30 and 24 hours for FE 999049 and follitropin α. The ovarian responses by number of follicles and serum concentrations of inhibin B and estradiol, were higher with FE 999049 than with follitropin α, AUC and C(max) for the two latter being >1.6-fold greater with FE 999049 than with follitropin α. These results indicate that administration of equal doses of FE 999049, expressed in a human cell line, and follitropin α, expressed in a CHO cell line, display different pharmacokinetic and pharmacodynamic properties in humans.

Sequential (hFSH + recFSH) vs homogenous (hFSH or recFSH alone) stimulation: clinical and biochemical (cumulus cell gene expression) aspects.

FSH is a key hormone in the regulation of follicular development. Together with the EGF network, these molecules mediate oocyte maturation and competence in preparation for the action of LH. FSH isoforms regulate distinct biological pathways and have specific effects on granulosa cell function and maturation of the ovarian follicle. Their dynamic interactions occur during the follicular cycle; short-living forms are predominant in the pre-ovulatory phase, whereas long-acting molecules characterize the luteal-follicular transition. Recombinant FSH (rFSH) molecules have a reduced number of isoforms and are less acidic, with a shorter half-life. We have investigated sequential stimulation, comparing hFSH + rFSH, vs. rFSH alone and hFSH alone for the entire stimulation phase. Sequential stimulation leads to an E2 per MII oocyte ratio that is much lower than is seen during treatment with the two drugs individually. Although there is a positive tendency in favor of the sequential treatment, there was no significant difference in pregnancy rates, even taking frozen embryos into consideration. The cumulus cell transcriptome varies considerably between the treatments, although with no clear significance. When comparing pregnant vs. non-pregnant patients, in general a decrease in mRNA expression can be observed in the pregnant patients, especially in expression of folic acid receptor 1 and ovostatin 2. This indicates that material has been transferred from CC to the oocyte. However, a common observation in the literature is that variations in the transcriptome of the cumulus cells are highly dependent upon the patient genotype; the potential for applying this strategy as a basis for selecting embryos is, at the very least, questionable.

The rate of high ovarian response in women identified at risk by a high serum AMH level is influenced by the type of gonadotropin.

The aim was to compare ovarian response and clinical outcome of potential high-responders after stimulation with highly purified menotropin (HP-hMG) or recombinant follicle-stimulating hormone (rFSH) for in vitro fertilisation/intracytoplasmic sperm injection. Retrospective analysis was performed on data collected in two randomized controlled trials, one conducted following a long GnRH agonist protocol and the other with an antagonist protocol. Potential high-responders (n = 155 and n = 188 in the agonist and antagonist protocol, respectively) were defined as having an initial anti-Müllerian hormone (AMH) value >75th percentile (5.2 ng/ml). In both protocols, HP-hMG stimulation in women in the high AMH category was associated with a significantly lower occurrence of high response (≥15 oocytes retrieved) than rFSH stimulation; 33% versus 51% (p = 0.025) and 31% versus 49% (p = 0.015) in the long agonist and antagonist protocol, respectively. In the potential high-responder women, trends for improved live birth rate were observed with HP-hMG compared with rFSH (long agonist protocol: 33% versus 20%, p = 0.074; antagonist protocol: 34% versus 23%, p = 0.075; overall population: 34% versus 22%, p = 0.012). In conclusion, the type of gonadotropin used for ovarian stimulation influences high-response rates and potentially clinical outcome in women identified as potential high-responders.

Spontaneous ovarian hyperstimulation syndrome.

Spontaneous forms of the ovarian hyperstimulation syndrome (sOHSS) are nearly always reported between 8 and 14 weeks of pregnancy and also with follicle-stimulating hormone (FSH) producing pituitary adenoma. The syndrome has been previously reported in rare instances of increased production of human chorionic gonadotrophin (hCG) such as multiple pregnancies, hydatiforme mole, polycystic ovary disease and elevated concentrations of thyroid-stimulating hormone (TSH) in hypothyreoidism. High levels of these hormones are able to stimulate by natural promiscuous activation the wild-type FSHr, resulting in sporadic presentations of the syndrome. Since 2003, only six different activating FSHr gene mutations have been reported in cases of familial or habitual sOHSS. In addition to five mutations which have been found in the transmembrane helices (Asp567Asn, Asp567Gly, Thr449Ile, Thr449Ala, Ile545Thr), the first germline mutation (c.383C > A, p. Ser 128 Tyr) in the extracelullar domain was identified. All five mutants were abnormally activated by TSH and normal levels of hCG while displaying constitutive activity. In contrast to these mutations, the p.Ser128Tyr mutant displayed an increase in sensitivity only toward hCG. Accordingly, the mutated FSHrs, may be hyperstimulated by the pregnancy-derived hCG or TSH, inducing the occurrence of the syndrome. In the differential diagnosis, malignancy, pregnancy luteoma and hyperreactio luteinalis would have to be excluded. In almost all of the cases the disease regresses spontaneously and could be managed expectantly or conservatively, but with termination of pregnancy or surgery in cases of complications.

FSHB-211 and FSHR 2039 are associated with serum levels of follicle-stimulating hormone and antimüllerian hormone in healthy girls: a longitudinal cohort study.

OBJECTIVE: To investigate whether genetic polymorphisms in the FSH pathway (FSHB-211 G→T and FSHR 2039 A→G) affect serum levels of FSH, antimüllerian hormone (AMH), and age at pubertal onset. FSH secretion and FSH signal transduction are enhanced in carriers of FSHB GG and FSHR AA, respectively. Furthermore, the combined genotype FSHB GG+FSHR AA is the most favorable for male gonadal function, but the effect of this genotype has never been evaluated in peripubertal females. AMH is a marker of ovarian function and is negatively correlated with FSH in prepubertal girls. DESIGN: Secondary analyses of a prospective cohort study. SETTING: General community. PATIENT(S): We examined 78 healthy girls twice yearly for 6 years; the median age at baseline was 9.3 years. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Hormone levels were measured by immunoassays, and DNA was isolated from blood and genotyped by restriction fragment length polymorphism of polymerase chain reaction-amplified regions. RESULT(S): Carriers of FSHB GG+FSHR AA had higher FSH before pubertal onset (median 2.2 vs. 1.5 IU/L) and lower AMH (13.8 vs. 19.4 pmol/L) compared with carriers of other genotypes. In crude analysis, girls with FSHB GG+FSHR AA entered puberty earlier, 9.7 vs. 10.6 years. However, the difference was no longer statistically significant after including interval-, right-, and left-censored data in a probit analysis. CONCLUSION(S): The combined effect of FSHB GG+FSHR AA may potentiate the FSH pathway, which increases serum levels of FSH and reduces AMH. Common variations in genes regulating follicle growth may affect AMH levels independently of the number of resting primordial follicles.

Role of follicle-stimulating hormone on biliary cyst growth in autosomal dominant polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a common genetic disorder characterized by the progressive development of renal and hepatic cysts. Follicle-stimulating hormone (FSH) has been demonstrated to be a trophic factor for biliary cells in normal rats and experimental cholestasis induced by bile duct ligation (BDL). AIMS: To assess the effect of FSH on cholangiocyte proliferation during ADPKD using both in vivo and in vitro models. METHODS: Evaluation of FSH receptor (FSHR), FSH, phospho-extracellular-regulated kinase (pERK) and c-myc expression in liver fragments from normal patients and patients with ADPKD. In vitro, we studied proliferating cell nuclear antigen (PCNA) and cAMP levels in a human immortalized, non-malignant cholangiocyte cell line (H69) and in an immortalized cell line obtained from the epithelium lining the hepatic cysts from the patients with ADPKD (LCDE) with or without transient silencing of the FSH gene. RESULTS: Follicle-stimulating hormone is linked to the active proliferation of the cystic wall and to the localization of p-ERK and c-myc. This hormone sustains the biliary growth by activation of the cAMP/ERK signalling pathway. CONCLUSION: These results showed that FSH has an important function in cystic growth acting on the cAMP pathway, demonstrating that it provides a target for medical therapy of hepatic cysts during ADPKD.

Polymorphisms in gonadotropin and gonadotropin receptor genes as markers of ovarian reserve and response in in vitro fertilization.

Since gonadotropins are the fundamental hormones that control ovarian activity, genetic polymorphisms may alter gonadal responsiveness to glycoproteins; hence they are important regulators of hormone activity at the target level. The establishment of the pool of primordial follicles takes place during fetal life and is mainly under genetic control. Consequently, single nucleotide polymorphisms (SNPs) in gonadotropins and their receptors do not seem to be associated with any significant modification in the endowment of nongrowing follicles in the ovary. Indeed, the age at menopause, a biological characteristic strongly related to ovarian reserve, as well as markers of functional ovarian reserve such as anti-Müllerian hormone and antral follicle count, are not different in women with different genetic variants. Conversely, some polymorphisms in FSH receptor (FSHR) seem to be associated with modifications in ovarian activity. In particular, studies suggest that the Ser680 genotype for FSHR is a factor of relative resistance to FSH stimulation resulting in slightly higher FSH serum levels, thus leading to a prolonged duration of the menstrual cycle. Moreover, some FSHR gene polymorphisms show a positive association with ovarian response to exogenous gonadotropin administration, hence exhibiting some potential for a pharmacogenetic estimation of the FSH dosage in controlled ovarian stimulation. The study of SNPs of the FSHR gene is an interesting field of research that could provide us with new information about the way each woman responds to exogenous gonadotropin administration during ovulation induction.

Longitudinal study of hormonal and physical development in young twins.

CONTEXT AND OBJECTIVE: Information on the correlation of normative reproductive hormone levels with physical development (Tanner stages) during puberty and on the influences of genes and environment on variation in these hormones and Tanner stages is limited. DESIGN, SETTING, AND PARTICIPANTS: One hundred twelve healthy 9-year-old twin pairs (n = 224) took part in a longitudinal study, of which 89 pairs participated again at age 12 years (n = 178). MAIN OUTCOME MEASURES: Morning urinary LH, FSH, estradiol, and salivary testosterone levels, determined by competitive immunoassays, were measured. Tanner stages were determined through physical examination. RESULTS: Over the 3-year interval, all hormone levels showed a 2- to 9-fold increase. LH and FSH at age 9 years predicted sex-specific Tanner stages at age 12 years in both boys and girls. Most of the associations between hormone levels at age 9 years and physical development at 12 years were explained by genetic influences. FSH in 9-year-old boys correlated with all hormone levels and Tanner stages at age 12 years. Moderate to high heritability estimates were found for hormone levels at both ages and in both sexes. In girls a shift from environmental (age 9 years) to genetic influences (age 12 years) was found for estradiol and pubic hair development, and for breast development a shift in the opposite direction was seen. CONCLUSIONS: During development LH and FSH (and testosterone in boys) levels predict secondary sexual characteristics in boys and girls 3 years later. These correlations are largely due to genes that are involved in both early pubertal hormone levels and subsequent physical development.

[The molecular design and drug development of recombinant long-acting follicle stimulating hormone].

Follicle-stimulating hormone (FSH) is a glycoprotein which regulates the development, growth, pubertal maturation and reproductive processes of the body. Exogenous FSH has been used to promote ovarian follicular growth and maturation in female and spermatogenesis in male. The relative short elimination half life and rapid metabolic clearance of current versions of FSH require a daily or twice-daily scheduled subcutaneous injection to maintain stable FSH level being not below the threshold during ovarian stimulation. The development of recombinant long-acting FSH with enhanced biological activities may be helpful for less injection therefore to improve patient compliance, while reducing patient stress and error rates. A number of technological strategies have been explored to develop recombinant longer-acting FSH. For examples, attachment of the C-terminal peptide (CTP) of the human chorionic gonadotropin beta subunit or a sequence containing potential glycosylation sites to either subunit of FSH, creation of a single chain containing the alpha and beta subunits of FSH combined with CTP or N-linked glycosylation signal sequence as a linker, or fusion of the Fc domain of IgGi to FSH. Based on the modifiable molecular structure and pharmacokinetic and pharmacodynamic properties of recombinant FSH, it is hopeful that more FSH drugs with prolonged half-life and increased bioactivity will be developed to meet the modern clinical demands.

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

CONTEXT: A polymorphism in the FSHB promoter (-211G>T, rs10835638) was shown to influence male serum FSH levels, whereas a polymorphism in the FSH receptor gene (FSHR; 2039A>G, rs6166) was previously shown to be associated with FSH levels in women only. OBJECTIVE: The objective of the study was to analyze the effects of both FSHB -211G>T and FSHR 2039A>G on male reproductive parameters. DESIGN AND SETTING: A total of 1213 German men attending an infertility clinic were genotyped by TaqMan assay. PATIENTS: Patients included male partners in infertile couples without known causes for male infertility. MAIN OUTCOME MEASURES: An association analysis of single and combined single-nucleotide polymorphism genotypes with clinical parameters was performed. RESULTS: The FSHB -211G>T T-allele showed significant dosage effects for FSH (-0.51 U/liter per T-allele), LH (0.28 U/liter), and bitesticular volume (-3.2 ml). Statistical significance was enhanced severalfold after a meta-analysis comprising 3017 men. TT carriers were significantly more prevalent among men with lower sperm counts. The FSHR 2039A>G G-allele exhibited nonsignificant trends for associations with higher FSH and reduced testicular volumes. However, in the combined model, FSHR 2039A>G significantly modulated the more dominant effect of FSHB -211G>T on serum FSH and testicular volume among the T-allele carriers. CONCLUSIONS: By analyzing both single-nucleotide polymorphisms for the first time, we convincingly show that indeed FSHR 2039A>G has an effect also in males. In the proposed model of the combined effects, FSHB -211G>T acts strongly on male reproductive parameters, whereas the FSHR 2039A>G effects were approximately 2-3 times smaller. Clinically this is of importance because oligozoospermic patients carrying unfavorable variants affecting FSH action may benefit from FSH treatment.

Molecular cloning and functional characterization of endogenous recombinant common marmoset monkey (Callithrix jacchus) follicle-stimulating hormone.

BACKGROUND: Common marmoset monkeys (Callithrix jacchus) are readily used in biomedical research. However, superovulation for embryonic stem cell production and developmental research still remain difficult. Inexplicably, follicle-stimulating hormone (FSH) as key player in superovulation has to be administered in extremely high dosages in this non-human primate compared to human. METHODS: To evaluate whether marmoset FSH (cjFSH) is functionally more competent than its human homologue on the marmoset FSH receptor (cjFSHR), we established in vitro a homologous system characterizing homologous and recombinantly produced cjFSH. RESULTS: Upon stimulation of two cell lines stably expressing either the marmoset or the human FSH receptor (cj/hFSHR), respectively, the second messenger signaling of the activated receptor displayed no significant difference in ED(50) values. Thermostability of cjFSH was significantly prolonged by roughly 20% on both FSHRs. CONCLUSION: High FSH dosage in marmoset superovulation cannot be explained by enhanced biopotency of the natural animal's gonadotropin.