The effects of endogenous FSH and its receptor on oogenesis and folliculogenesis in female Alligator sinensis

BACKGROUND

The precise mechanisms of hormone action responsible for the full course of events modulating folliculogenesis in crocodilian have not been determined, although histological features have been identified.

RESULTS

The Alligator sinensis ovarian morphological characteristics observed at 1, 15, 30, 60, 90, and 300 days post hatching(dph) revealed that the dynamic changes in germ cells varied in different meiotic and developmental stages, confirming that the processes of folliculogenesis were protracted and asynchronous. The presence of endogenous follicle-stimulating hormone(FSH) mRNA and protein expression within the cerebrum at 1 dph, in parallel with the increase in germ cells within the germ cell nests(Nest) from 1 dph to 15 dph, suggested that endocrine regulation of the pituitary-gonad axis is an early event in oogonia division. Furthermore, the endogenous expression of FSH showed a trend of negative feedback augmentation accompanied by the exhaustion of maternal yolk E₂ observed at 15 dph. Such significant elevation of endogenous FSH levels was observed to be related to pivotal events in the transition from mitosis to meiosis, as reflected by the proportion of oogonia during premeiosis interphase, with endogenous FSH levels reaching a peak at the earliest time step of 1 dph. In addition, the simultaneous upregulation of premeiotic marker STRA8 mRNA expression and the increase in endogenous FSH further verified the above speculation. The strongly FSHr-positive label in the oocytes within Pre-previtellogenic follicles was synchronized with the significant elevation of ovarian cAMP detected at 300 dph, which suggested that diplotene arrest maintenance during early vitellogenesis might be FSH dependent. In addition, preferential selection in asynchronous meiotic initiation has been supposed to act on somatic supportive cells and not directly on germ cells via regulation of FSH that in turn affects downstream estrogen levels. This suggestion was verified by the reciprocal stimulating effect of FSH and E₂ on the accelerated meiotic marker SYCP3 and by the inhibited cell apoptosis demonstrated in ovarian cell culture in vitro.

CONCLUSION

The corresponding results contribute an expansion of the understanding of physiological processes and shed some light on the specific factors responsible for gonadotropin function in the early folliculogenesis of crocodilians.

Comparison of mouse ovarian follicular development and gene expression in the presence of ovarian tissue extract and sodium selenite: An experimental study

Background

Ovarian tissue extract (OTE) and sodium selenite (SS) enhance the growth and maturation of preantral follicles in a dose-dependent manner.

Objective

The present study was designed to bring more information regarding the mechanism of OTE and SS on the mRNA expression of follicle-stimulating hormone receptors (FSHR) and the proliferation cell nuclear antigens (PCNA) of in vitro matured isolated follicles.

Materials and Methods

The tissue extract was prepared from adult ovaries. The preantral follicles (n = 266) were isolated from 12-16-day-old mice and cultured in the control, experimental I (10 ng/ml SS), and experimental II (OTE) groups for 12 days. The follicular diameter, survival, and maturation rates, also, the production of 17-β-estradiol and progesterone, and the follicular expression of PCNA and FSH receptor genes were analyzed.

Results

The survival rate of follicles in the SS-treated group (84.58%) was significantly higher than that OTE (75.63%; p = 0.023) and control (69.38%; p = 0.032) groups. The mean diameter of culture follicles in experimental group I (403.8 μm) and experimental group II (383.97 μm) increased significantly in comparison with the control group (342.05 μm; p = 0.032). The developmental rate of follicles, percentages of antrum formation, released metaphase II oocytes (p = 0.027; p = 0.019 respectively), production of hormones and the expression of 2 studied genes were significantly increased in both experimental groups in compare with control group (p = 0.021; p = 0.023 respectively).

Conclusion

The OTE and SS have a positive effect on development of mouse preantral follicles via over-expression of FSHR and PCNA genes.

Resolving the challenge of insoluble production of mature human growth differentiation factor 9 protein (GDF9) in E. coli using bicistronic expression with thioredoxin

Growth differentiation factor 9 (GDF9) is an oocyte-derived protein with fundamental functions in folliculogenesis. While the crucial contributions of GDF9 in follicular survival have been revealed, crystallographic studies of GDF9 structure have not yet been carried out, essentially due to the insoluble expression of GDF9 in E. coli and lack of appropriate source for structural studies. Therefore, in this study, we investigated the impact of different expression rate of bacterial thioredoxin (TrxA) using bicistronic expression constructs to induce the soluble expression of mature human GDF9 (hGDF9) driven by T7 promoter in E. coli. Our findings revealed that in BL21(DE3), the high rate of TrxA co-expression at 30 °C was sufficiently potent for the soluble expression of hGDF9 and reduction of inclusion body formation by 4 fold. We also successfully confirmed the bioactivity of the purified soluble hGDF9 protein by evaluation of follicle-stimulating hormone receptor gene expression in bovine cumulus cells derived from small follicles. This study is the first to present an effective approach for expression of bioactive form of hGDF9 using TrxA co-expression in E. coli, which may unravel the current issues regarding structural analysis of hGDF9 protein and consequently provide a better insight into hGDF9 functions and interactions.

The first case of novel variants of FSHR mutation causing primary amenorrhea in two siblings in Korea

Follicle-stimulating hormone receptor (FSHR) mutation is a rare cause of amenorrhea. We report the first case of FSHR mutations in Korea. Two female siblings, aged 16 (patient 1) and 19 (patient 2) years, were referred to the pediatric endocrinology clinic because of primary amenorrhea despite normal breast budding. Gonadotropin-releasing hormone stimulation test showed markedly elevated luteinizing hormone and follicle-stimulating hormone with a relatively low level of estrogen, suggesting hypergonadotropic hypogonadism. Pelvic magnetic resonance imaging revealed a bicornuate uterus in patient 1 and uterine hypoplasia with thinning of the endometrium in patient 2. The progesterone challenge test revealed no withdrawal of bleeding. After two months of administration of combined oral contraceptives, menarche was initiated at regular intervals. To determine the genetic cause of amenorrhea in these patients, whole exome sequencing (WES) was performed, which revealed a compound heterozygous FSHR mutation, c.1364T>G (p.Val455Gly) on exon 10, and c.374T>G (p.Leu125Arg) on exon 4; both of which were novel mutations and were confirmed by Sanger sequencing. The patients maintained regular menstruation and improved bone mineral density while taking combined oral contraceptives, calcium, and vitamin D. Therefore, FSHR mutations can be the cause of amenorrhea in Koreans, and WES facilitates diagnosing the rare cause of amenorrhea.

Association of single-nucleotide polymorphisms in the ESR2 and FSHR genes with poor ovarian response in infertile Jordanian women

Objective

Poor ovarian response (POR) refers to a subnormal follicular response that leads to a decrease in the quality and quantity of the eggs retrieved after ovarian stimulation during assisted reproductive treatment (ART). The present study investigated the associations of multiple variants of the estrogen receptor 2 (ESR2) and follicle-stimulating hormone receptor (FSHR) genes with POR in infertile Jordanian women undergoing ART.

Methods

Four polymorphisms, namely ESR2 rs1256049, ESR2 rs4986938, FSHR rs6165, and FSHR rs6166, were investigated in 60 infertile Jordanian women undergoing ART (the case group) and 60 age-matched fertile women (the control group), with a mean age of 33.60±6.34 years. Single-nucleotide polymorphisms (SNPs) were detected by restriction fragment length polymorphism and then validated using Sanger sequencing.

Results

The p-value of the difference between the case and control groups regarding FSHR rs6166 was very close to 0.05 (p=0.054). However, no significant differences were observed between the two groups in terms of the other three SNPs, namely ESR2 rs1256049, ESR2 rs4986938, and FSHR rs6165 (p=0.561, p=0.433, and p=0.696, respectively).

Conclusion

The association between FSHR rs6166 and POR was not statistically meaningful in the present study, but the near-significant result of this experiment suggests that statistical significance might be found in a future study with a larger number of patients.

The Effects of Inhibin B in the Chemotherapy Drug-Induced Premature Ovarian Insufficiency Mice and hPMSCs Treatment

Human placenta mesenchymal stem cells (hPMSCs), have been extensively investigated on the treatment of many diseases. This study was to explore the effects of hPMSCs treatment on the chemotherapy drug-induced premature ovarian insufficiency (POI) mice. Cyclophosphamide (120 mg/kg) and busulfan (30 mg/kg) or cyclophosphamide (70 mg/kg) induced POI mice were used and hPMSCs were injected through tail vein. The hormone levels of serum, morphological changes, the expression and quantitative analysis of inhibin B (INHBB) and FSHR protein, and apoptosis of granulosa cells in ovary were detected. The granulosa cells (GCs) were detected from ovaries of mice and the different concentration of cyclophosphamide on GCs were detected by MTT assay. The apoptosis of GCs was detected by FITC Annexin V Apoptosis Detection Kit. The significant increase in FSH and decrease in E₂ and INHBB were observed. Expression of human nuclei was observed in the stroma of ovaries. INHBB and FSHR levels of ovaries were reduced in the POI mice. Following hPMSCs treatment, the amounts of INHBB and FSHR significantly increased close to normal levels. The granulosa cells apoptosis increased in the POI ovaries but decreased after hPMSCs treatment. Moreover, cyclophosphamide has no effect on the GCs and no statistic difference was measured in vitro. The effects of hPMSCs treatment reduce the apoptosis of granulosa cells and restore the ovarian reserve capacity in chemotherapeutic drug-induced POI mice. The data help to further explore new potential clinical therapeutic approach for POI patients.

Characterization of gonadotropin receptors Fshr and Lhr in Japanese medaka, Oryzias latipes

Reproduction in vertebrates is controlled by the brain-pituitary-gonad axis, where the two gonadotropins follicle-stimulating hormone (Fsh) and luteinizing hormone (Lh) play vital parts by activating their cognate receptors in the gonads. The main purpose of this work was to study intra- and interspecies ligand promiscuity of teleost gonadotropin receptors, since teleost receptor specificity is unclear, in contrast to mammalian receptors. Receptor activation was investigated by transfecting COS-7 cells with either Fsh receptor (mdFshr, tiFshr) or Lh receptor (mdLhr, tiLhr), and tested for activation by recombinant homologous and heterologous ligands (mdFshβα, mdLhβα, tiFshβα, tiLhβα) from two representative fish orders, Japanese medaka (Oryzias latipes, Beloniformes) and Nile tilapia (Oreochromis niloticus, Cichliformes). Results showed that each gonadotropin preferentially activates its own cognate receptor. Cross-reactivity was detected to some extent as mdFshβα was able to activate the mdLhr, and mdLhβα the mdFshr. Medaka pituitary extract (MPE) stimulated CRE-LUC activity in COS-7 cells expressing mdlhr, but could not stimulate cells expressing mdfshr. Recombinant tiLhβα, tiFshβα and tilapia pituitary extract (TPE) could activate the mdLhr, suggesting cross-species reactivity for mdLhr. Cross-species reactivity was also detected for mdFshr due to activation by tiFshβα, tiLhβα, and TPE, as well as for tiFshr and tiLhr due to stimulation by mdFshβα, mdLhβα, and MPE. Tissue distribution analysis of gene expression revealed that medaka receptors, fshr and lhr, are highly expressed in both ovary and testis. High expression levels were found for lhr also in brain, while fshr was expressed at low levels. Both fshr and lhr mRNA levels increased significantly during testis development. Amino acid sequence alignment and three-dimensional modelling of ligands and receptors highlighted conserved beta sheet domains of both Fsh and Lh between Japanese medaka and Nile tilapia. It also showed a higher structural homology and similarity of transmembrane regions of Lhr between both species, in contrast to Fshr, possibly related to the substitution of the conserved cysteine residue in the transmembrane domain 6 in medaka Fshr with glycine. Taken together, this is the first characterization of medaka Fshr and Lhr using homologous ligands, enabling to better understand teleost hormone-receptor interactions and specificities. The data suggest partial ligand promiscuity and cross-species reactivity between gonadotropins and their receptors in medaka and tilapia.

Cell-based evidence regarding the role of FSH in prostate cancer

INTRODUCTION

Conversion of androgen-responsive prostate cancer (CaP) to castration-resistant CaP is associated with an acceleration of the disease that often requires treatment modalities other than androgen deprivation therapy only. Recently, follicle-stimulating hormone (FSH) has been shown to play a role in CaP growth, and clinical data showed that high serum concentration of FSH in chemically castrated CaP patients was associated with a shorter time of progression to castration-resistant CaP. In this study, we sought to investigate if FSH could have direct effects on CaP cells, possibly through the androgen receptor and androgen receptor regulated genes, such as prostate-specific antigen (PSA).

MATERIALS AND METHODS

The human CaP cell lines PC-3, LNCaP and C4-2, and nonmalignant PNT1A cells, were utilized to investigate the effects of FSH. qPCR, Western blotting analysis, and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymetoxyphenyl)-2-(4-sulfophenyl)-2H tetrazolium assays were performed in order to analyze the FSH effects.

RESULTS

The FSH receptor was present in all cell lines except PNT1A. FSH significantly increased PSA mRNA (P < 0.01) and protein (P < 0.03) levels in C4-2 cells in a dose-dependent manner. In LNCaP cells, FSH also increased PSA protein level, although to a lesser extent than in C4-2 cells, and the expression was reduced by the antiandrogen enzalutamide. In PC-3 cells, FSH was shown to increase their proliferation (P < 0.03) and β-catenin expression.

CONCLUSION

These findings demonstrate that FSH may have a direct effect in CaP in an androgen-depleted environment. However, further research is needed to understand the significance of direct FSH action in the maintenance of CaP growth at the different phases of transition from androgen dependence to androgen independence.

Cloning, characterization, and molecular expression of gonadotropin receptors in European hake (Merluccius merluccius), a multiple-spawning species

Teleosts have many spawning strategies and the hormonal control of gametogenesis is not well defined among the species or even, between sexes. To increase the knowledge of gonadotropin hormones, we studied the trend by gene expression of gonadotropin receptors in the follicles and testis at different maturity stages in the European hake (Merluccius merluccius), a multiple-spawning species. With this aim, fshr and lhr were sequenced, characterized, and their gene expression was quantified in oocytes and in testes at different maturity stages. The deduced amino acid sequences were used to phylogenetic studies and evidenced that both receptors are phylogenetically closed to other gadoid species. The gene expression of both receptors was poorly expressed in primary follicles, increased in vitellogenic follicles and to later decrease in hydrated oocytes. In testis, highest levels of lhr were detected during spermiation, while levels of fshr were constant. For the first time, a histological analysis was performed in European hake testes showing an unrestricted lobular testis. To better elucidate the mechanisms involved in the oogenesis of the European hake, the expression of estrogen receptor and cyp19a was also investigated displaying high levels in all classes of follicles. All these data allow to increase the knowledge on reproductive physiology of an important socioeconomical species and it seeks to shed more light on the role of the receptors here studied during gametogenesis of multiple-spawning fish.

Pharmacoperones for Misfolded Gonadotropin Receptors

The gonadotropin receptors (luteinising hormone receptor; LHR and follicle-stimulating hormone receptor; FSHR) are G protein-coupled receptors (GPCRs) that play an important role in the endocrine control of reproduction. Thus genetic mutations that cause impaired function of these receptors have been implicated in a number of reproductive disorders. Disease-causing genetic mutations in GPCRs frequently result in intracellular retention and degradation of the nascent protein through misfolding and subsequent recognition by cellular quality control machinery. The discovery and development of novel compounds termed pharmacological chaperones (pharmacoperones) that can stabilise misfolded receptors and restore trafficking and plasma membrane expression are therefore of great interest clinically, and promising in vitro data describing the pharmacoperone rescue of a number of intracellularly retained mutant GPCRs has provided a platform for taking these compounds into in vivo trials. Thienopyrimidine small molecule allosteric gonadotropin receptor agonists (Org 42599 and Org 41841) have been demonstrated to have pharmacoperone activity. These compounds can rescue cell surface expression and in many cases, hormone responsiveness, of a range of retained mutant gonadotropin receptors. Should gonadotropin receptor selectivity of these compounds be improved, they could offer therapeutic benefit to subsets of patients suffering from reproductive disorders attributed to defective gonadotropin receptor trafficking.

Expression of FSHR in chondrocytes and the effect of FSH on chondrocytes

OBJECTIVE

Chondrocytes express many kinds of hormone receptors. The function of Follicle stimulating hormone (FSH) in the ovary is mediated by FSH receptor (FSHR). FSH receptor (FSHR) is found in many non-ovarian tissues, however it has been unclear if chondrocytes express FSHR. The purpose of this study is to determine it.

METHODS

Mouse primary chondrocytes and human articular cartilage tissues were examined. The expression and sequence of FSHR mRNA by reverse transcription polymerase chain reaction (RT-PCR) and sequenced, respectively, and its protein expression was tested using western blotting and location was observed under immunofluorescence microscopy. Ovarian tissue was as a positive control. After FSH stimulated mouse chondrocytes, intracellular cAMP levels were assessed by ELISA, and gene expression relative to Mouse WNT Signaling Pathway was tested by RT² Profiler PCR Arrays.

RESULTS

FSHR was detected at the transcriptional level and confirmed to have the same sequence as that of ovary-derived mRNA of FSHR. FSHR proteins presented at the same line as the positive proteins of ovary, in mouse chondrocytes and human cartilage tissue, respectively. FSHR proteins were located at the cell membrane. Intracellular cAMP contents were significantly elevated up to 7-fold in mouse chondrocytes by forskolin (100 mM) (P < 0.001); however, different doses of FSH did not change the cAMP contents in mouse primary chondrocytes. RT² Profiler PCR Arrays demonstrated that FSH could cause changes in gene expression among the 84 preordained genes, such as Fosl1, Rhou, and Dkk1, in mouse chondrocytes relative to the control.

CONCLUSION

Mouse chondrocytes and human articular cartilage express functional FSHR. Moreover, FSH can act on chondrocytes and cause genetic changes.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02640976.

The follicle-stimulating hormone receptor Asn680Ser polymorphism is associated with preterm birth in Hispanic women

OBJECTIVE

Recently, a study based on the analysis of accelerated evolution of related genes at birth identified the follicle-stimulating hormone receptor (FSHR) as a possible candidate for the development of preterm delivery. Additionally, FSHR expression has been described in extragonadal tissue including the placenta. Therefore, the aim of the present study was to determine the association between the N680S polymorphism of the follicle-stimulating hormone receptor and preterm birth in a population of Hispanic women.

METHODS

Placenta samples were obtained from 64 women who had preterm births and 54 control cases. DNA was extracted and genotyped for the N680S FSHR gene polymorphism by polymerase chain reaction-restriction fragment length polymorphism. The χ² test and t-test were used to calculate statistical significance.

RESULTS

Statistically significant differences in genotype frequencies for the N680S polymorphism were observed between preterm and term groups (p = .04). Based on the Akaike information criterion values, the dominant model showed that the NN genotype had a significantly increased risk of preterm birth compared with the SS + NS genotype (OR 2.52, 95% CI 1.20-5.33, p = .02).

CONCLUSIONS

The results herein suggest that the FSHR polymorphism N680S is significantly associated with preterm birth in the Hispanic population.

Molecular characterization and quantification of the follicle-stimulating hormone receptor in turbot (Scophthalmus maximus)

Molecular cloning, characterization, and functional analysis of follicle-stimulating hormone receptor (FSHR) in female turbot (Scophthalmus maximus) were evaluated. Results showed that the full-length FSHR cDNA was 3824 bp long and contained a 2202 bp open reading frame that encoded a mature protein of 733 amino acids (aa) and a signal peptide of 18 aa. Multiple sequence analyses showed that turbot FSHR has high homology with the corresponding genes of other teleosts and significant homology with that of Hippoglossus hippoglossus. Turbot FSHR has the typical structural architecture of glycoprotein hormone receptors consisting of a large N-terminal extracellular domain, seven transmembrane domains and short C-terminal intracellular domain. FSHR mRNA was found to be abundant in the ovaries, but deficient in eyes, intestine, brain, muscle, gills, spleen, stomach, heart and kidney. Furthermore, FSHR mRNA was found to increase gradually from pre-vitellogenesis to migratory nucleus stages, with the highest values observed during the late vitellogenesis stage of the reproductive cycle. However, FSHR mRNA was found to decrease dramatically during the atresia stage. Meanwhile, functional analysis with HEK293T cells continual expressing FSHR demonstrated that FSHR was specifically stimulated by ovine FSH, but not ovine LH. These results indicate that turbot FSHR is mainly involved in the stimulation of vitellogenesis, regulation of oocyte maturation as well as promotion of ovarian development via specific ligand binding. These findings open doors to further investigation of physiological functions of FSHR, which will be valuable for fish reproduction and broodstock management.

Impact of follicle-stimulating hormone receptor variants in female infertility

PURPOSE

Follicle-stimulating hormone (FSH) and its receptor play a major role in the development of follicles and regulation of steroidogenesis in the ovary and spermatogenesis in the testis. We aim to analyze the role of FSHR gene variants (single nucleotide polymorphisms (SNPs) in exon 10 (codon 307 and 680) and in the core promoter region (at position -29) and Ala189Val inactivating mutation) in Turkish infertile women. There were studies analyzing the effects of the SNPs in exon 10 (codon 307 and 680) and in the core promoter region (at position -29) of the FSHR gene on spermatogenesis, but to our knowledge, there were no studies analyzing the effects of these three SNP combinations on female fertility.

METHODS

In this study, the allelic, genotype, and haplotype frequency distributions of these three SNPs in the FSHR gene were analyzed in 102 infertile women and 99 unrelated healthy control individuals. The distribution of the polymorphisms was conformed by Hardy-Weinberg equilibrium test.

RESULTS

There were no statistical differences (P > 0.05) in the allele, genotype, and haplotype frequencies of the polymorphisms and FSH, luteinizing hormone (LH), estradiol (E2), and prolactin (PRL) levels between the infertile patients and the controls. However, a significant relation was found between 307 SNP GA genotype and FSH level ≥12. We did not find any homozygous or heterozygote mutations in infertile patients and healthy fertile controls.

CONCLUSION

The present study was the first study analyzing gma mutation and the polymorphism of the FSHR core promoter at position -29 alone and in combination with the two common SNPs in exon 10 in Turkish infertile women population. These findings indicate the significance of Ala307Thr GA genotype may be a predictive marker for poor ovarian reserve and infertility.

Development of Follicle-Stimulating Hormone Receptor Binding Probes to Image Ovarian Xenografts

The Follicle-Stimulating Hormone Receptor (FSHR) is used as an imaging biomarker for the detection of ovarian cancer (OC). FSHR is highly expressed on ovarian tumors and involved with cancer development and metastatic signaling pathways. A decapeptide specific to the FSHR extracellular domain is synthesized and conjugated to fluorescent dyes to image OC cells in vitro and tumors xenograft model in vivo. The in vitro binding curve and the average number of FSHR per cell are obtained for OVCAR-3 cells by a high resolution flow cytometer. For the decapeptide, the measured EC50 was 160 μM and the average number of receptors per cell was 1.7 × 10⁷. The decapeptide molecular imaging probe reached a maximum tumor to muscle ratio five hours after intravenous injection and a dose-dependent plateau after 24-48 hours. These results indicate the potential application of a small molecular weight imaging probe specific to ovarian cancer through binding to FSHR. Based on these results, multimeric constructs are being developed to optimize binding to ovarian cells and tumors.

Constitutive activity in gonadotropin receptors

Constitutively active mutants (CAMs) of gonadotropin receptors are, in general, rare conditions. Luteinizing hormone-choriogonadotropin receptor (LHCGR) CAMs provoke the dramatic phenotype of familial gonadotropin-independent isosexual male-limited precocious puberty, whereas in females, there is not yet any identified phenotype. Only one isolated follicle-stimulating hormone receptor (FSHR) CAM (Asp567Gly) has so far been detected in a single male patient, besides other FSHR weak CAMs linked to pregnancy-associated ovarian hyperstimulation syndrome or to impaired desensitization and internalization. Several animal models have been developed for studying enhanced gonadotropin action; in addition to unraveling valuable new information about the possible phenotypes of isolated FSHR and LHCGR CAMs in women, the information obtained from these mouse models has served multiple translational goals, including the development of new diagnostic and therapeutic targets as well as the prediction of phenotypes for mutations not yet identified in humans. Mutagenesis and computational studies have shed important information on the physiopathogenic mechanisms leading to constitutive activity of gonadotropin receptors; a common feature in these receptor CAMs is the release of stabilizing interhelical interactions between transmembrane domains (TMDs) 3 and 6 leading to an increase, with respect to the wild-type receptor, in the solvent accessibility at the cytosolic extension of TMDs 3, 5, and 6, which involves the highly conserved Glu/Asp-Arg-Tyr/Trp sequence. In this chapter, we summarize the structural features, functional consequences, and mechanisms that lead to constitutive activation of gonadotropin receptor CAMs and provide information on pharmacological approaches that might potentially modulate gonadotropin receptor CAM function.

The follicle-stimulating hormone receptor: a novel target in genitourinary malignancies

Follicle-stimulating hormone (FSH) is a central hormone in mammalian reproductive biology. The FSH receptor (FSHR), which was previously believed to be expressed primarily in the ovary and testis, was recently found to be expressed in the tumor blood vessels of many solid tumor types, including prostate adenocarcinoma, urothelial carcinoma, and renal cell carcinoma. While the biologic significance of FSHR in tumor blood vessels has yet to be elucidated, FSHR may contribute to neoangiogenesis. FSHR has been reported to be expressed by prostate cancer cells and, thus, targeting FSHR in prostate cancer may be of particular utility. In this report, we discuss the finding of FSHR in tumor blood vessels and review the literature concerning FSHR in genitourinary malignancy. We also discuss the features that make FSHR an appealing target for therapeutic and imaging purposes and the potential utility of FSHR as a prognostic and/or predictive biomarker in genitourinary cancers.

Investigating the association between polymorphism of follicle-stimulating hormone receptor gene and ovarian response in controlled ovarian hyperstimulation

AIM

The aim of the study was to investigate the association between follicle-stimulating hormone receptor (FSHR) gene polymorphism at Position 680 and the outcomes of controlled ovarian hyperstimulation for in vitro fertilization and embryo transfer (IVF-ET) in infertile women.

MATERIALS AND METHODS

One hundred and eight patients under 35 years of age who underwent IVF-ET procedures were included in this study. The hormonal profile and treatment of all patients were analyzed and FSHR polymorphism was examined by polymerase chain reaction-restriction fragment length polymorphism. Women from all groups were classified based on polymorphisms at Position 680, occupied either by asparagines (Asn) or serine (Ser) as Asn/Asn, Asn/Ser, and Ser/Ser genotype.

RESULT

Our study showed that all patients in the Asn/Asn group were normal responders and in the Asn/Ser group 64.8% were normal responders and 21.1% and 14.1% were poor and hyper responders respectively. In the Ser/Ser group we did not have normal responders and 46.7% of these patients were poor responders and 53.3% were hyper responders.

CONCLUSION

FSH receptor polymorphism is correlated with response to ovarian stimulation.