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1,517 result(s) for "Luteinizing Hormone - genetics"
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A randomised trial examining inflammatory signaling in acutely induced hyperinsulinemia and hyperlipidemia in normal weight women-the reprometabolic syndrome
Obesity, is a state of chronic inflammation, characterized by elevated lipids, insulin resistance and relative hypogonadotropic hypogonadism. We have defined the accompanying decreased Luteinizing Hormone (LH), Follicle-Stimulating Hormone (FSH), ovarian steroids and reduced pituitary response to Gonadotropin-releasing Hormone (GnRH) as Reprometabolic syndrome, a phenotype that can be induced in healthy normal weight women (NWW) by acute infusion of free fatty acids and insulin. To identify potential mediators of insulin and lipid-related reproductive endocrine dysfunction. Secondary analysis of crossover study of eumenorrheic reproductive aged women of normal Body Mass Index (BMI) (<25 kg/m2) at an academic medical center. Participants underwent 6-hour infusions of either saline/heparin or insulin plus fatty acids (Intralipid plus heparin), in the early follicular phase of sequential menstrual cycles, in random order. Euglycemia was maintained by glucose infusion. Frequent blood samples were obtained. Pooled serum from each woman was analyzed for cytokines, interleukins, chemokines, adipokines, Fibroblast Growth Factor-21 (FGF-21) and markers of endoplasmic reticulum (ER) stress (CHOP and GRP78). Wilcoxon signed-rank tests were used to compare results across experimental conditions. Except for Macrophage Inflammatory Protein-1β (MIP-1β), no significant differences were observed in serum levels of any of the inflammatory signaling or ER stress markers tested. Acute infusion of lipid and insulin, to mimic the metabolic syndrome of obesity, was not associated with an increase in inflammatory markers. These results imply that the endocrine disruption and adverse reproductive outcomes of obesity are not a consequence of the ambient inflammatory environment but may be mediated by direct lipotoxic effects on the hypothalamic-pituitary-ovarian (HPO) axis.
Cumulus Cells Gene Expression Profiling in Terms of Oocyte Maturity in Controlled Ovarian Hyperstimulation Using GnRH Agonist or GnRH Antagonist
In in vitro fertilization (IVF) cycles controlled ovarian hyperstimulation (COH) is established by gonadotropins in combination with gonadotropin-releasing hormone (GnRH) agonists or antagonists, to prevent premature luteinizing hormone (LH) surge. The aim of our study was to improve the understanding of gene expression profile of cumulus cells (CC) in terms of ovarian stimulation protocol and oocyte maturity. We applied Affymetrix gene expression profiling in CC of oocytes at different maturation stages using either GnRH agonists or GnRH antagonists. Two analyses were performed: the first involved CC of immature metaphase I (MI) and mature metaphase II (MII) oocytes where 359 genes were differentially expressed, and the second involved the two GnRH analogues where no differentially expressed genes were observed at the entire transcriptome level. A further analysis of 359 differentially genes was performed, focusing on anti-Müllerian hormone receptor 2 (AMHR2), follicle stimulating hormone receptor (FSHR), vascular endothelial growth factor C (VEGFC) and serine protease inhibitor E2 (SERPINE2). Among other differentially expressed genes we observed a marked number of new genes connected to cell adhesion and neurotransmitters such as dopamine, glycine and γ-Aminobutyric acid (GABA). No differential expression in CC between the two GnRH analogues supports the findings of clinical studies where no significant difference in live birth rates between both GnRH analogues has been proven.
Mechanism of female CHH caused by compound heterozygous mutations in the LHB gene
Background Luteinizing hormone (LH) plays a crucial role in the postnatal development and maturation of gonads. Inactivating mutations of the luteinizing hormone beta subunit ( LHB )gene are extremely rare and can result in congenital hypogonadotropic hypogonadism (CHH). Methods We conducted DNA sequencing on an 18-year-old female patient with undetectable LH and clinical symptoms of CHH. Pulsatile GnRH was administered to promote puberty development. In vitro construction of mutant genes, confocal microscopy, and protein functional assays were used to investigate the effects of genetic variants on hormone function and secretion. Experiments were conducted in HEK293T cells to examine the colocalization and dimerization of LH subunits, as well as to measure intracellular and extracellular LH concentrations. Results Compound heterozygous mutations of c.252C>G (p.F84L) and c.364G>A (p.G122S) were found in the patient’s genome. Pulsatile GnRH therapy was effective in promoting puberty development and ovulation. The LH alpha subunit was found to co-localize with both mutant beta subunits after immunofluorescence staining, and immunoprecipitation detected the dimerization of the LH alpha subunit with both mutant beta subunits. Higher intracellular LH concentrations and lower extracellular LH concentrations compared to the wild type indicate secretion dysfunction for LH. Conclusion Compound heterozygous mutations of c.252C>G (p.F84L) and c.364G>A (p.G122S) in the LHB gene may lead to CHH for female patient. These mutations do not impair the expression and dimerization of the alpha and beta subunits, but they do prevent the secretion of LH. The study expands our understanding of the clinical manifestation of LHB gene mutations in females and provides a treatment for these patients.
Metformin induces a prompt decrease in LH-stimulated testosterone response in women with PCOS independent of its insulin-sensitizing effects
Background The use of insulin-sensitizing drugs has been shown to improve both the reproductive and the metabolic aspects of PCOS. However, the mechanisms by which metformin exerts its effects in PCOS are still not completely understood. There is growing evidence of a direct effect of metformin on ovarian steroidogenesis, independent of its effects on insulin sensitivity. Methods We evaluated the short-term effects of metformin compared to placebo on basal and LH- stimulated androgen secretion as well as on hormonal and metabolic parameters in 19 women with PCOS during a four-day randomized, double-blinded placebo-controlled clinical trial. In a three month follow-up evaluation, we investigated the longer-term therapeutic effects of metformin on ovulation, metabolic and endocrine parameters. Results Compared to placebo, 2 days of metformin was associated with a borderline significant reduction in the free androgen index (FAI) (p = 0.05) and with a reduction in the serum concentration of LH-stimulated testosterone (T) (p = 0.03). Following three months of use, a decline in serum T was observed, independent of changes in weight, metabolic parameters, or insulin sensitivity. Conclusions In women with PCOS, Metformin induces a prompt decrease in LH-stimulated T secretion after only several days of use. This action precedes the medication’s effects on insulin sensitivity or weight loss.
Recombinant LH supplementation during IVF cycles with a GnRH-antagonist in estimated poor responders: A cross-matched pilot investigation of the optimal daily dose and timing
Although it is widely accepted that patients, who are considered poor responders to in vitro fertilization (IVF) benefit from recombinant luteinizing hormone (rLH) supplementation during an in vitro fertilization cycle, particularly when gonadotropin-releasing hormone (GnRH) antagonist (ant) treatment is used the optimal administration timing and daily dose of rLH remains to be elucidated. The aim of the present study was to investigate the optimal timing of rLH-supplementation to improve ovarian response, embryo quality, endometrial thickness and pregnancy rate in infertile, estimated poor responders to IVF, undergoing GnRH-ant treatment. In addition, the present study aimed to evaluate the optimal daily dose to achieve the same outcomes. A prospective-randomized-cross-matched investigation was performed on 40 patients undergoing a GnRH-ant-treatment-cycle The patients were randomly assigned to either group A (rLH-75 IU/day) or group B (rLH-150 IU/day) and further randomized into subgroup A1/B1, in which rLH was administered at recombinant follicle stimulating hormone (rFSH) administration, and subgroup A2/B2, in which rLH was administered at GnRH-ant administration. Patients who did not become pregnant during the first cycle (35 patients), were treated a second time, cross-matched for groups and subgroups. Improved ovarian response, embryo quality and pregnancy rate were achieved by administering rLH at 150 IU/day, starting from GnRH-ant administration, independently from the total rLH dose administered. Improved endometrial thickness at oocyte retrieval day was achieved by administering rLH at 150 IU from the start of rFSH administration. These data led to the hypothesis that ovarian responses are affected by the timing of administration more than the total-dose of rLH. The optimal window to administer rLH appears to be the mid-to-late follicular phase, despite the fact that rLH-supplementation in the early follicular phase appeared to increase endometrial thickness and to enhance its morphology. Standardization of the optimal daily dose and supplementation timing of rLH may resolve the debate regarding its efficacy in increasing the number of pregnancies and neonatal survival rates.
Homozygous nonsense mutation Trp28X in the LHB gene causes male hypogonadism
PurposeThe purpose of this study was to investigate a novel mutation in the luteinizing hormone beta-subunit (LHB) gene in one male patient with hypogonadism due to selective luteinizing hormone (LH) deficiency.MethodsSanger sequencing of one 28-year-old man born to consanguineous parents was performed. Treatment with human chorionic gonadotropin (hCG) (2000 IU, twice a week) was initiated for 3 months, followed by 5000 IU weekly to date.ResultsWe identified a novel c.84G>A[p.W28X] nonsense LHB mutation. The W28X mutation produces a truncated LHB peptide of seven amino acids, which prevents the synthesis of intact LH. After 40 days of treatment with hCG, the patient exhibited a few spermatozoa in the semen. Treated for 6 months, the patient exhibited normal seminal parameters.ConclusionsWe identified a novel mutation in the LHB gene in a male patient with hypogonadism and provided evidence that LHB nonsense mutation can cause selective LH deficiency. We reconfirmed hCG treatment may restore male fertility due to LHB mutation.
Follicular fluid hormonal profile and cumulus cell gene expression in controlled ovarian hyperstimulation with recombinant FSH: effects of recombinant LH administration
Purpose Down-regulation with gonadodropin-releasing agonist (GnRH-a) protocol during IVF stimulation leads to a severe endogenous LH suppression, which may affect the follicular development. The aim of the study was to evaluate the effects of recombinant LH (r-LH) administration, during late follicular development stages, in recombinant FSH (r-FSH) stimulated cycles on follicular fluid (FF) parameters and on cumulus cell quality. Methods Twenty patients undergoing IVF were stimulated in a long GnRH agonist protocol with r-FSH alone or with r-LH supplementation when the leading follicle reached diameter of 14 mm. FF was collected at the time of oocyte retrieval from 32 follicles ≥ 18 mm. Serum FSH, LH, estradiol (E 2 ), and progesterone (P 4 ) were evaluated on the day of hCG administration. Intra-follicular E 2 , P 4 , AMH and TGF-β were assayed. Total RNA from 18 individual cumuli was isolated for gene expression analyses. Results R-LH increased FF P 4 levels. FF TGF-β levels and PTGS2 and HAS2 expression in cumulus cells (CCs) positively correlated with increased P 4 levels observed in FFs, while a negative correlation was found between P 4 and AMH levels. Conclusions FF positive correlation between P 4 and TGF-β levels and CC expression of PTGS2 and HAS2 suggest an association with a better follicle quality. In addition, our data suggest that late follicular phase r-LH supplementation leads to a more advanced stage of follicular maturation.
AgRP to Kiss1 neuron signaling links nutritional state and fertility
Mammalian reproductive function depends upon a neuroendocrine circuit that evokes the pulsatile release of gonadotropin hormones (luteinizing hormone and follicle-stimulating hormone) from the pituitary. This reproductive circuit is sensitive to metabolic perturbations. When challenged with starvation, insufficient energy reserves attenuate gonadotropin release, leading to infertility. The reproductive neuroendocrine circuit is well established, composed of two populations of kisspeptin-expressing neurons (located in the anteroventral periventricular hypothalamus, Kiss1AVPV, and arcuate hypothalamus, Kiss1ARH), which drive the pulsatile activity of gonadotropin-releasing hormone (GnRH) neurons. The reproductive axis is primarily regulated by gonadal steroid and circadian cues, but the starvation-sensitive input that inhibits this circuit during negative energy balance remains controversial. Agouti-related peptide (AgRP)-expressing neurons are activated during starvation and have been implicated in leptin-associated infertility. To test whether these neurons relay information to the reproductive circuit, we used AgRP-neuron ablation and optogenetics to explore connectivity in acute slice preparations. Stimulation of AgRP fibers revealed direct, inhibitory synaptic connections with Kiss1ARH and Kiss1AVPV neurons. In agreement with this finding, Kiss1ARH neurons received less presynaptic inhibition in the absence of AgRP neurons (neonatal toxin-induced ablation). To determine whether enhancing the activity of AgRP neurons is sufficient to attenuate fertility in vivo, we artificially activated them over a sustained period and monitored fertility. Chemogenetic activation with clozapine N-oxide resulted in delayed estrous cycles and decreased fertility. These findings are consistent with the idea that, during metabolic deficiency, AgRP signaling contributes to infertility by inhibiting Kiss1 neurons.
Genome-wide analyses identify 25 infertility loci and relationships with reproductive traits across the allele frequency spectrum
Genome-wide association studies (GWASs) may help inform the etiology of infertility. Here, we perform GWAS meta-analyses across seven cohorts in up to 42,629 cases and 740,619 controls and identify 25 genetic risk loci for male and female infertility. We additionally identify up to 269 genetic loci associated with follicle-stimulating hormone, luteinizing hormone, estradiol and testosterone through sex-specific GWAS meta-analyses ( n  = 6,095–246,862). Exome sequencing analyses reveal that women carrying testosterone-lowering rare variants in some genes are at risk of infertility. However, we find no local or genome-wide genetic correlation between female infertility and reproductive hormones. While infertility is genetically correlated with endometriosis and polycystic ovary syndrome, we find limited genetic overlap between infertility and obesity. Finally, we show that the evolutionary persistence of infertility-risk alleles may be explained by directional selection. Taken together, we provide a comprehensive view of the genetic determinants of infertility across multiple diagnostic criteria. Genome-wide analyses identify variants associated with infertility and reproductive hormone levels but find limited polygenic overlap between reproductive hormone levels and infertility at the population level.
Genome-wide association study with 1000 genomes imputation identifies signals for nine sex hormone-related phenotypes
Genetic factors contribute strongly to sex hormone levels, yet knowledge of the regulatory mechanisms remains incomplete. Genome-wide association studies (GWAS) have identified only a small number of loci associated with sex hormone levels, with several reproductive hormones yet to be assessed. The aim of the study was to identify novel genetic variants contributing to the regulation of sex hormones. We performed GWAS using genotypes imputed from the 1000 Genomes reference panel. The study used genotype and phenotype data from a UK twin register. We included 2913 individuals (up to 294 males) from the Twins UK study, excluding individuals receiving hormone treatment. Phenotypes were standardised for age, sex, BMI, stage of menstrual cycle and menopausal status. We tested 7,879,351 autosomal SNPs for association with levels of dehydroepiandrosterone sulphate (DHEAS), oestradiol, free androgen index (FAI), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, progesterone, sex hormone-binding globulin and testosterone. Eight independent genetic variants reached genome-wide significance (P<5 × 10(-8)), with minor allele frequencies of 1.3-23.9%. Novel signals included variants for progesterone (P=7.68 × 10(-12)), oestradiol (P=1.63 × 10(-8)) and FAI (P=1.50 × 10(-8)). A genetic variant near the FSHB gene was identified which influenced both FSH (P=1.74 × 10(-8)) and LH (P=3.94 × 10(-9)) levels. A separate locus on chromosome 7 was associated with both DHEAS (P=1.82 × 10(-14)) and progesterone (P=6.09 × 10(-14)). This study highlights loci that are relevant to reproductive function and suggests overlap in the genetic basis of hormone regulation.