UMLS:C0021359 - FACTA Search

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Query: UMLS:C0021359 (infertility)
26,075 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

FSH plays a central role in normal reproductive function, i.e. control of follicular maturation in the female and initiation and maintenance of spermatogenesis in the male. The effects of FSH are mediated by its interaction with a specific receptor that belongs to the superfamily of guanine nucleotide-binding protein-coupled receptors. Due to the microheterogeneity of gonadotropins, measurement of immunoreactivity does not necessarily reflect their bioactivity. Mutations in gonadotropin beta-subunits, which affect bioreactivity and/or immunoreactivity of gonadotropins, have been described as causes of infertility, thus highlighting the need for rapid and convenient methods to measure bioactivity. To establish a model system for recombinant in vitro bioassays for FSH that would obviate the use of live animals, we developed a strategy for efficient expression of the rat FSH receptor (FSHR) in L cells. A cell line, FSHR 7/12, was developed that bound [125I]FSH with high affinity (Kd 1.42 nM) and responded to human FSH with an increase in cAMP accumulation. Untreated human serum was found to have an unspecific inhibitory effect on cAMP formation. This effect could be thoroughly avoided by mild heating (10 min at 56 C) of serum samples before addition to cells without detectable loss of FSH immunoactivity or bioactivity. Studies on the hormone-sensitive adenylyl cyclase system of transformed FSHR 7/12 cells and of the parental Ltk- cells showed that the cellular response to FSH was highly specific. Using a parallel line assay design, FSHR 7/12 cells were used to validate a novel recombinant in vitro bioassay relying on intracellular cAMP accumulation as a readout system. Up to 10% of serum could be added to the incubation buffer without leading to nonparallelism to the standard curve. When 70 serum samples of male patients attending an infertility clinic were analyzed, the novel assay system displayed high sensitivity and a close correlation (r > 0.8; P < 0.01) to the established rat Sertoli cell aromatase bioassay and to a highly specific fluoroimmunoassay. When sera of 25 normal menstruating women were analyzed for FSH bioactivity at different stages of the menstrual cycle, a midcycle FSH peak followed by a decline in the late luteal phase could be discerned. The analysis of 26 serum samples of postmenopausal women revealed a close correlation between FSH values obtained by the novel in vitro bioassay and by a fluoroimmunoassay (r = 0.90; P < 0.01). Thus, the present in vitro bioassay represents a sensitive, rapid, and convenient model system to measure bioactive FSH in human serum.
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PMID:In vitro bioassay for human serum follicle-stimulating hormone (FSH) based on L cells transfected with recombinant rat FSH receptor: validation of a model system. 795 43

We report a woman with primary amenorrhoea and infertility associated with an isolated deficiency of pituitary follicle-stimulating hormone (FSH), but normal luteinizing hormone (LH) secretion. Ovulation was induced by administration of exogenous FSH and resulted in a successful pregnancy. Sequence analysis of the FSH beta-subunit gene indicated that she is homozygous for a two nucleotide frameshift deletion in the coding sequence. Her mother and son are heterozygous for this mutation. This deletion results in an alteration of amino acid codons 61-86 followed by a premature termination codon. The predicted truncated beta-subunit peptide lacks regions which are important for association with the alpha subunit and for binding to and activation of the FSH receptor. Abnormalities of FSH structure or function might be an under recognised but treatable cause of infertility.
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PMID:Primary amenorrhoea and infertility due to a mutation in the beta-subunit of follicle-stimulating hormone. 822 Apr 32

Gonadal function is controlled by the two pituitary gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH). While LH mainly regulates gonadal steroidogenesis, FSH is considered essential for folliculogenesis in the female and spermatogenesis in the male. We recently discovered that an inactivating point mutation in the FSH receptor (R) gene causes a recessively inherited form of hypergonadotropic ovarian failure in homozygous females. This 566C-->T mutation, predicting an alanine to valine substitution, is located in exon 7 of the FSHR gene, in the region encoding the extracellular domain of the receptor molecule. Functional testing showed a clear-cut reduction in ligand binding and signal transduction by the mutated receptor. Hence, lack of FSH function is incompatible with ovarian follicular maturation and female fertility. In the male, FSH is generally considered essential for the pubertal initiation of spermatogenesis and maintenance of quantitatively normal sperm production in adults. We report here the first characterization of males homozygous for an inactivating FSHR mutation. They have variable degrees of spermatogenic failure, but, surprisingly, do not show azoospermia or absolute infertility. These results question the essential role of FSH for the initiation of spermatogenesis, and demonstrate that FSH is more important for female than for male fertility.
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PMID:Men homozygous for an inactivating mutation of the follicle-stimulating hormone (FSH) receptor gene present variable suppression of spermatogenesis and fertility. 902 Aug 51

Raised activity of the LH axis caused by activating mutations of LH receptor gene presents with precocious puberty in boys, analogous to the presentation of LH secreting pituitary adenomas (Faggiano et al., 1983; Ambrosi et al., 1990). LH "hyperactivity' in females appears to have no effect. Hyperactivity of the FSH axis caused by activating mutations of the FSH receptor gene might parallel the presentation of FSH secreting pituitary adenomas with Sertoli cell hypertrophy in men (Heseltine et al., 1989) or reversible premature ovarian failure in women (Moses et al., 1986; Okuda et al., 1989). Indeed the first such case to be described is a male who maintained testicular volume and fertility in the absence of gonadotrophins (Gromoll et al., 1996). Female precocious puberty may require hyperactivity of both gonadotrophin axes because of the "two-cell' arrangement required for ovarian oestrogen production. Mutations of the Gs alpha-subunit gene can mimic this situation in some women with the McCune-Albright syndrome (Malchoff et al., 1994). Lack of LH activity caused by defects in the LH beta molecule causes infertility in men and that resulting from inactivating mutations of the LH receptor gene causes Leydig cell agenesis in men while ovarian development in females is relatively normal. Lack of FSH activity caused by defects in the FSH beta caused infertility in a female, and that caused by inactivating mutations of the FSH receptor gene causes ovarian dysgenesis in women but only variable depression of spermatogenesis in men. Incidentally, this categorization of reproductive disorders may also be applied to the TSH axis. Pituitary adenomas and activating mutations of the TSH receptor gene (Parma et al., 1993) cause hyperthyroidism and TSH beta gene defects (Hayashizaki et al., 1989) and inactivating mutations of the TSH receptor gene (Sunthornthepvarakul et al., 1995) cause hypothyroidism. To complete the analogy with thyroid disorders, it is curious that despite structural similarities with the TSH receptor, neither LH nor FSH receptor autoantibodies have a prominent role in ovarian pathophysiology (Moncayo et al., 1989; Van Weissenbruch et al., 1991; Simoni et al., 1993). Complete gonadotrophin resistance is likely to be very rare, however, so what are we likely to find in partial gonadotrophin resistance? Might the "resistant ovary syndrome' come right in the end, with corresponding minor FSH receptor mutations? Experience with insulin and androgen resistance syndromes suggests that such a scenario is unlikely. Insulin receptor gene mutations are found in extreme Type A insulin resistance but not in moderate forms of insulin resistance (O'Rahilly et al., 1991). Androgen receptor gene mutations are found in nearly all cases of complete androgen insensitivity but rarely in partial forms (Patterson et al., 1994). Mild resistance to hormone action is rarely detectable in relatives who are heterozygous for receptor mutations which are inherited in a recessive pattern. It seems unlikely therefore, that individuals heterozygous for inactivating receptor mutations will manifest symptoms of reproductive disorders and account for common conditions. Thus, while mutation analysis provides new insights into the gender specific role of the gonadotrophins the cause of early gonadal failure in the majority of individuals remains a mystery.
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PMID:Clinical manifestations of genetic defects affecting gonadotrophins and their receptors. 903 30

Infertile men with Sertoli-cell-only syndrome (SCO) have highly elevated serum FSH immunoactivity related to the degree of histological damage. The activity that serum FSH exerts at the target site depends on its glycosylation pattern and FSH receptor (FSHR) function. Either could be impaired, leading to failure of spermatogenesis. The aim of the present investigation was to study bioactivity and the glycosylation pattern of serum FSH and the occurrence of mutations in the FSH receptor in infertile patients with SCO compared to normal men. Blood was taken from 19 patients with bilateral testicular focal or complete SCO and eight normozoospermic controls. FSH bioactivity in serum was measured using an in-vitro FSH bioassay based on recombinant rat FSHR. The glycosylation pattern of serum FSH was determined by concanavalin A chromatography. Inhibin B was determined in serum using a recently available assay. Genomic DNA extracted from blood lymphocytes was amplified by PCR using primers specific for the FSHR and screened by single-stranded conformation polymorphism gel electrophoresis. Men with SCO showed significantly higher FSH in-vitro bioactivity (34.9 +/- 5.0 IU/l) than controls (9.6 +/- 0.8 IU/l: p < 0.01), as well as significantly elevated FSH immunoactivity (14.9 +/- 1.7 IU/l) compared to controls (3.1 +/- 0.5; p < 0.01). Immunoactivity of serum FSH was correlated with in-vitro bioactivity (r = 0.9; p < 0.001) and was related to the degree of testicular damage (proportion of SCO-tubules) (ANOVA: p < 0.001) and total testicular volume (r = -0.76; p < 0.01). An inverse relationship between serum FSH and inhibin B levels (r = -0.93; p < 0.001) was found. In the serum of SCO patients a slight increase in less glycosylated FSH isoforms was found (6.7 +/- 0.6% versus 3.6 +/- 0.3%; p < 0.05). No mutations of the FSHR were observed in SCO patients. We conclude that the spermatogenic failure observed in infertile patients with SCO histology and elevated FSH serum levels can be explained neither by a change in FSH bioactivity nor by mutations in the FSHR. The slight change in the FSH glycosylation pattern is probably related to higher hormonal secretion rates in SCO patients. The inverse relationship between serum FSH and inhibin B points to an intact endocrine testicular-pituitary circuit responsible for the compensatory increase of FSH in SCO.
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PMID:Does the gonadotrophic axis play a role in the pathogenesis of Sertoli-cell-only syndrome? 920 88

Mutations of gonadotropin beta subunits or gonadotropin receptors are involved in some reproductive diseases leading to alterations of pubertal maturation or infertility. Homozygous inactivation of LH results in absence of pubertal maturation and hypogonadism in the male, whereas inactivation of FSH causes primary amenorrhea in females. Mutations of the gonadotropin receptors are classified into activating (the receptor is also active in the absence of the hormone: gain-of-function mutations) and inactivating types (the receptor is not properly processed and/or the hormone cannot bind: loss-of-function mutations). Activating mutations of the LH receptor have been described in familiar and sporadic forms of male-limited pseudoprecocious puberty, whereas they do not express any phenotype in females. The only activating mutation of the FSH receptor described to date was found in a hypophysectomized man who was fertile despite undetectable serum gonadotropin levels; the effects of constitutive FSH receptor activity occurring with normal pituitary function are not known. Homozygous inactivations of the LH and FSH receptor invariably lead to amenorrhea in genotypically female subjects. In males, inactivation of the LH receptor in its more severe form results in a clinical picture similar to the syndrome of complete androgen resistance, but milder forms of hypoandrogenization have been described as well. The clinical consequences of homozygous inactivation of the FSH receptor in males are associated with subfertility. Finally, polymorphic variants of both the gonadotropin LH and the FSH receptor are present in the normal population.
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PMID:Molecular pathophysiology of the pituitary-gonadal axis. 936 74

The gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH) bind specific receptors, members of the G protein-coupled receptor superfamily. Mutations of gonadotropin receptors are classified into activating (constitutively active or gain-of-function mutations) and inactivating (loss-of-function mutations). Activating mutations of the LH receptor have been described in familial and sporadic forms of male-limited pseudoprecocious puberty, whereas they do not appear to have any particular phenotype in females. The only activating mutation of the FSH receptor described to date was found in a hypophysectomized man who was fertile despite undetectable serum gonadotropin levels; the effects of constitutive FSH receptor activity in the context of normal pituitary function are not known. Homozygous inactivating mutations of the LH and FSH receptor invariably lead to amenorrhea in genotypical female subjects. In males, inactivation of the LH receptor in its more severe form results in a clinical picture similar to the syndrome of complete androgen resistance, but milder forms of hypoandrogenization have been described as well. In males, homozygous inactivation of the FSH receptor can also be associated with infertility. Finally, polymorphic variants of the FSH receptor are present in the normal population.
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PMID:Molecular pathophysiology and clinical manifestations of gonadotropin receptor defects. 961 88

Follicle stimulating hormone (FSH) is considered to be essential for spermatogenesis. Therefore, genetic abnormalities of FSH signalling on testicular Sertoli cells would be expected to affect sperm production negatively in males. Inactivating FSH receptor mutations have been reported earlier in both males and females. All affected males had elevated FSH serum concentrations and abnormal sperm parameters. We postulated that inactivating FSH receptor mutations might be a cause of oligozoospermia or azoospermia and reviewed the clinical data of 151 male intracytoplasmic sperm injection (ICSI) candidates with special attention to FSH serum concentrations. The exclusion criteria for mutation screening of the FSH receptor gene were: a history of operative sterilization or testicular malignancy, congenital abnormality other than cryptorchidism, and a chromosomal aberration or a Y-chromosome microdeletion. The inclusion criteria were: male (ICSI candidate) with azoospermia or oligoasthenoteratozoospermia (OAT) and elevated FSH serum concentrations. In total, 23 males with OAT and five males with azoospermia were tested for mutations of the coding sequences and the intron-exon boundaries of the FSH receptor gene by polymerase chain reaction (PCR) followed by single strand conformation polymorphism analysis (SSCP). Neutral polymorphisms were readily detected using this technique in both probands and controls. None of the 28 selected patients showed a pathogenic FSH receptor mutation. Mutations in the FSH receptor gene are not a common cause of infertility in ICSI candidates.
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PMID:Screening male intracytoplasmic sperm injection candidates for mutations of the follicle stimulating hormone receptor gene. 975 76

Pituitary gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone stimulate the gonads by regulating germ cell proliferation and differentiation. FSH receptors (FSH-Rs) are localized to testicular Sertoli cells and ovarian granulosa cells and are coupled to activation of the adenylyl cyclase and other signaling pathways. Activation of FSH-Rs is considered essential for folliculogenesis in the female and spermatogenesis in the male. We have generated mice lacking FSH-R by homologous recombination. FSH-R-deficient males are fertile but display small testes and partial spermatogenic failure. Thus, although FSH signaling is not essential for initiating spermatogenesis, it appears to be required for adequate viability and motility of the sperms. FSH-R-deficient females display thin uteri and small ovaries and are sterile because of a block in folliculogenesis before antral follicle formation. Although the expression of marker genes is only moderately altered in FSH-R -/- mice, drastic sex-specific changes are observed in the levels of various hormones. The anterior lobe of the pituitary gland in females is enlarged and reveals a larger number of FSH- and thyroid-stimulating hormone (TSH)-positive cells. The phenotype of FSH-R -/- mice is reminiscent of human hypergonadotropic ovarian dysgenesis and infertility.
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PMID:Impairing follicle-stimulating hormone (FSH) signaling in vivo: targeted disruption of the FSH receptor leads to aberrant gametogenesis and hormonal imbalance. 981 48

We have described previously in the Finnish population an inactivating point mutation (566C-->T) in the human FSH receptor (FSHR) gene. In women, this mutation causes hypergonadotropic ovarian failure with arrest of follicular maturation and infertility, whereas in men, there is variable suppression of spermatogenesis, but no absolute infertility. To determine whether the same FSHR mutation occurs in other populations, its frequency was determined in Finland, Switzerland, Denmark, and the Chinese population of Singapore. The mutation was screened for using genomic DNA extracted from whole blood or dried blood spots. Exon 7 of the FSHR gene was first amplified using a pair of biotinylated primers. The PCR products were then immobilized on streptavidin-coated microtitration wells and hybridized using short allele-specific oligonucleotide probes labeled with europium. Time-resolved fluorometry was used for europium signal detection. To test the reliability of this method, 40 isolated DNA samples and 35 dried blood spot samples were blindly tested for the 566C-->T FSHR mutation. The analyses yielded identical results with denaturing gradient gel electrophoresis and allele-specific restriction enzyme digestion of the same samples, thus demonstrating the reliability of the tested method. Automation of this procedure allows the screening of large numbers of samples, which was subsequently carried out to investigate the frequency of the 566C-->T mutation in the study populations. A total of 4981 samples from the above-mentioned 4 countries were analyzed. The frequency of the 566C-->T mutation was 0.96% for all Finnish samples (n=1976), with a strong enrichment of the mutant allele in the northeastern part of the country. Only 1 mutation carrier was identified in the samples from Switzerland (n=1162), whereas none was found in samples from Denmark (n=1094) and the Singapore Chinese (n=540). These results suggest that the 566C-->T mutation of the FSHR gene is enriched in Finland, but is uncommon in other populations.
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PMID:The frequency of an inactivating point mutation (566C-->T) of the human follicle-stimulating hormone receptor gene in four populations using allele-specific hybridization and time-resolved fluorometry. 985 74

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