GnRH Receptor Research Articles

Evaluating conserved domains and motifs of decapod gonadotropin-releasing hormone G protein-coupled receptor superfamily.

G protein-coupled receptors (GPCRs) are an ancient family of signal transducers that are both abundant and consequential in metazoan endocrinology. The evolutionary history and function of the GPCRs of the decapod superfamilies of gonadotropin-releasing hormone (GnRH) are yet to be fully elucidated. As part of which, the use of traditional phylogenetics and the recycling of a diminutive set of mis-annotated databases has proven insufficient. To address this, we have collated and revised eight existing and three novel GPCR repertoires for GnRH of decapod species. We developed a novel bioinformatic workflow that included clustering analysis to capture likely GnRH receptor-like proteins, followed by phylogenetic analysis of the seven transmembrane-spanning domains. A high degree of conservation of the sequences and topology of the domains and motifs allowed the identification of species-specific variation (up to ~70%, especially in the extracellular loops) that is thought to be influential to ligand-binding and function. Given the key functional role of the DRY motif across GPCRs, the classification of receptors based on the variation of this motif can be universally applied to resolve cryptic GPCR families, as was achieved in this work. Our results contribute to the resolution of the evolutionary history of invertebrate GnRH receptors and inform the design of bioassays in their deorphanization and functional annotation.

Diplotype-based assessment of GNRHR gene polymorphisms and their role in determining litter size at birth in the Malabari goat population of South India

The Gonadotropin Releasing Hormone Receptor (GNRHR) gene, a key regulator of the hypothalamo-pituitary-gonadal axis, plays a pivotal role in modulating reproductive potential in mammals by influencing the release of gonadotropins. In this study, we conducted a comprehensive population genetic analysis of haplotypes and diplotypes of the GNRHR and explored their association with litter size at birth in the prolific Malabari goat breed of South India. Utilizing PCR-single strand conformation polymorphism (SSCP) and PCR-sequencing-based typing (SBT) techniques, we genotyped 185 Malabari goats for diplotypes encompassing specific single nucleotide polymorphisms (SNPs) at c.–33A>G, c.–29 T>G, c.48 G>A, c.75 G>A, and c.209 T>G loci of the GNRHR gene. The PCR-SSCP and PCR-SBT revealed the presence of seven diplotypes and six haplotypes within the study population. Our results, as determined by ordinal logistic regression analysis, demonstrated a highly significant (p<0.01) influence of GNRHR diplotypes on litter size at birth up to the third parity, with a significant (p<0.05) effect observed in the fourth parity in Malabari goats. Specifically, the odds of multiple births were found to be 53.3% and 80.7% higher for AGAGG/ATGGT diplotypes compared to AGAGG/AGAGG diplotypes in the first and second parity, respectively. Furthermore, the odds ratio analysis highlighted a higher percentage of multiple births in AGAGG/AGAAG diplotypes during the third and fourth parities compared to other diplotypes in Malabari goats. Collectively, our findings suggest that heterozygote diplotypes confer a reproductive advantage over homozygous diplotypes for litter size at birth in the Malabari goat breed.

Expression and localization of HPG axis-related genes in Carassius auratus with different ploidy.

In the Dongting water system, the Carassius auratus (Crucian carp) complex is characterized by the coexistence of diploid forms (2n=100, 2nCC) and polyploidy forms. The diploid (2nCC) and triploid C.auratus (3n=150, 3nCC) had the same fertility levels, reaching sexual maturity at one year. The nucleotide sequence, gene expression, methylation, and immunofluorescence of the gonadotropin releasing hormone 2(Gnrh2), Gonadotropin hormone beta(Gthβ), and Gonadotropin-releasing hormone receptor(Gthr) genes pivotal genes of the hypothalamic-pituitary-gonadal (HPG) axis were analyzed. The analysis results indicated that Gnrh2, follicle-stimulating hormone receptor(Fshr), and Lethal hybrid rescue(Lhr) genes increased the copy number and distinct structural differentiation in 3nCC compared to that in 2nCC. The transcript levels of HPG axis genes in 3nCC were higher than 2nCC (P<0.05), which could promote the production and secretion of sex steroid hormones conducive to the gonadal development of 3nCC. Meanwhile, the DNA methylation levels in the promoter regions of the HPG axis genes were lower in 3nCC than in 2nCC. These results suggested that methylation of the promoter region had a potential regulatory effect on gene expression after triploidization. Immunofluorescence showed that the localization of the Fshβ, Lhβ, and Fshr genes between 3nCC and 2nCC remained unchanged, ensuring the normal expression of these genes at the corresponding sites after triploidization. Relevant research results provide cell and molecular biology evidence for normal reproductive activities such as gonad development and gamete maturation in triploid C. auratus, and contribute to further understanding of the genetic basis for fertility restoration in triploid C. auratus.

Social isolation and aggression training lead to escalated aggression and hypothalamus-pituitary-gonad axis hyperfunction in mice

Although the participation of sex hormones and sex hormone-responsive neurons in aggressive behavior has been extensively studied, the role of other systems within the hypothalamus-pituitary-gonadal (HPG) axis remains elusive. Here we assessed how the gonadotropin-releasing hormone (GnRH) and kisspeptin systems are impacted by escalated aggression in male mice. We used a combination of social isolation and aggression training (IST) to exacerbate mice’s aggressive behavior. Next, low-aggressive (group-housed, GH) and highly aggressive (IST) mice were compared regarding neuronal activity in the target populations and hormonal levels, using immunohistochemistry and ELISA, respectively. Finally, we used pharmacological and viral approaches to manipulate neuropeptide signaling and expression, subsequently evaluating its effects on behavior. IST mice exhibited enhanced aggressive behavior compared to GH controls, which was accompanied by elevated neuronal activity in GnRH neurons and arcuate nucleus kisspeptin neurons. Remarkably, IST mice presented an increased number of kisspeptin neurons in the anteroventral periventricular nucleus (AVPV). In addition, IST mice exhibited elevated levels of luteinizing hormone (LH) in serum. Accordingly, activation and blockade of GnRH receptors (GnRHR) exacerbated and reduced aggression, respectively. Surprisingly, kisspeptin had intricate effects on aggression, i.e., viral ablation of AVPV-kisspeptin neurons impaired the training-induced rise in aggressive behavior whereas kisspeptin itself strongly reduced aggression in IST mice. Our results indicate that IST enhances aggressive behavior in male mice by exacerbating HPG-axis activity. Particularly, increased GnRH neuron activity and GnRHR signaling were found to underlie aggression whereas the relationship with kisspeptin remains puzzling.

Enhancement of Female Rat Fertility via Ethanolic Extract from Nigella sativa L. (Black Cumin) Seeds Assessed via HPLC-ESI-MS/MS and Molecular Docking.

The characteristic chemical composition of Nigella seeds is directly linked to their beneficial properties. This study aimed to investigate the phytochemical composition of Nigella sativa seeds using a 100% ethanolic extract using HPLC-ESI-MS/MS. Additionally, it explored the potential biological effects of the extract on female rat reproduction. Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH), Estrogen (E2), and Progesterone (P4) hormone levels were also assessed, along with the morphological and histological effects of the extract on ovarian, oviductal, and uterine tissues. Molecular docking was performed to understand the extract's activity and its role in regulating female reproduction by assessing its binding affinity to hormonal receptors. Twenty metabolites, including alkaloids, saponins, terpenes, flavonoids, phenolic acids, and fatty acids, were found in the ethanolic extract of N. sativa seeds through the HPLC-ESI-MS/MS study. The N. sativa seed extract exhibited strong estrogenic and LH-like activities (p < 0.05) with weak FSH-like activity. Furthermore, it increased the serum levels of LH (p < 0.05), P4 hormones (p < 0.001), and E2 (p < 0.0001). Molecular docking results displayed a strong interaction with Erβ, LH, GnRH, and P4 receptors, respectively. Based on these findings, N. sativa seeds demonstrated hormone-like activities, suggesting their potential as a treatment for improving female fertility.

(290) Impact of Neoadjuvant Relugolix on Patient-Reported Sexual Function and Bother

Abstract Introduction Relugolix is an oral GnRH receptor antagonist used in combination with radiation therapy in the treatment of unfavorable prostate cancer. It has been shown to achieve rapid and profound testosterone suppression (total testosterone &amp;lt;20 ng/dL) without the need for bothersome injections. Such low testosterone levels may impact sexual functioning and perceptions. Objective Given the potential benefits of Relugolix over other androgen deprivation therapies (ADTs), this prospective study sought to assess neoadjuvant Relugolix-induced sexual dysfunction prior to the initiation of stereotactic body radiation therapy (SBRT). Methods Prospective, patient-reported data was collected from a male cohort diagnosed with localized prostate cancer and subsequently treated with neoadjuvant Relugolix and SBRT. Relugolix was initiated at least 2 months prior to SBRT. Sexual function and bother were assessed via the sexual domain of the validated Expanded Prostate Index Composite (EPIC-26) survey which includes five function questions (erections and orgasm) and one overall bother question. Individual scores ranged from 0-100 with higher scores reflecting improved function/less bother. EPIC-26 was collected for each patient at pre-Relugolix baseline and one hour prior to SBRT initiation. Individual items were evaluated for statistical significance (paired t-test, p &amp;lt; 0.05) and clinical significance by minimally important difference (MID, +/- 0.5 SD from baseline score). Results Between July 2021 and January 2023, 49 patients with localized prostate cancer were treated with neoadjuvant Relugolix (4-6 months) and SBRT (36.25-40 Gy in 5 fractions) at Georgetown University Hospital per institutional protocol IRB 12-1775. The median age was 73 years. 27% of patients were black and 26.1% were obese (BMI ≥30 kg/m2). Patients initiated Relugolix at a median of 3.6 months prior to SBRT. 82% of patients had intermediate risk disease. All individual EPIC sexual function scores declined in a similar manner following neoadjuvant Relugolix therapy. These declines were both statistically and clinically significant. There was no statistically or clinically significant change in the EPIC sexual overall bother score. Conclusions In concordance with known side effects of ADT, neoadjuvant Relugolix was associated with a significant decline in self-reported sexual function. However, patients indicated only a minimal and non-significant increase in bother. Relugolix was well-tolerated as patients on Relugolix did not subjectively find their sexual dysfunction troublesome. Future investigations should compare outcomes while on Relugolix directly to GnRH agonist-induced sexual dysfunction. Disclosure No.

Utilization of patient-reported outcomes to assess adherence to relugolix when combined with radiation therapy.

319 Background: Injectable GnRH receptor agonists have been shown to improve cancer control when combined with radiotherapy (RT). Relugolix is an oral GnRH receptor antagonist that achieves rapid testosterone suppression. Non-adherence to oral medications due to poor social support or bothersome side effects may increase the risk of cancer recurrence. This prospective study sought to evaluate early testosterone suppression and relugolix drug adherence when combined with RT. Utilization of patient-reported outcomes (PROs) to evaluate oral medication adherence and guide intervention may improve appropriate utilization of oral medications. This study focuses on the use of the Simplified Medication Adherence Questionnaire (SMAQ) as a tool to assess relugolix adherence. Methods: Relugolix was initiated at least 2 months prior to questionnaire administration. Adherence was assessed using the SMAQ. Total testosterone levels were obtained at the time of SMAQ administration. Castration was defined as serum testosterone ≤ 50 ng/dL. Poor drug adherence was delineated as failure to reach castration or non-adherence per the SMAQ (any non-adherence answer, missed &gt;2 doses in last week or since last visit). To compare the demographic and clinical characteristics of patients who adhered to treatment versus who did not, t-test, Wilcoxon rank sum test, Chi-square test, and Fisher’s exact test were used. A p-value &lt;0.05 determined statistical significance. Results: Between May 2021 and June 2023, 92 men were treated at Georgetown with relugolix and RT per an institutional protocol. The median age was 73 years, and 32% of patients were non-white. Patients initiated relugolix at a median of 5 months prior to the SMAQ (2-24 months). 97% of patients achieved castration (≤ 50 ng/dL) at the time of the SMAQ. 96% of men reported always taking relugolix at the appropriate time. 3% discontinued medication due to bothersome side effects, 18% reported forgetting to take the medication, and 2% reported missing a dose during the weekend. 99% and 97% did not miss a dose more than 2 times in the last week and since the last visit, respectively. Overall patient-reported drug adherence was 73%. Conclusions: Relugolix allows for high rates of castration and drug adherence when combined with RT. Monitoring drug adherence during treatment allows for prompt detection of non-adherence and timely intervention. Future studies should focus on how to optimally incorporate this questionnaire into patient management. [Table: see text]

Maintenance of patient-reported quality of life (EQ-5D-3L) post neoadjuvant relugolix prior to the initiation of prostate radiation therapy.

117 Background: Injectable GnRH receptor agonists have been shown to improve cancer control when combined with radiotherapy (RT) for unfavorable intermediate- to high-risk prostate cancer. Relugolix is a new oral GnRH receptor antagonist that achieves high rates of rapid profound castration (total testosterone &lt; 20 ng/dL), which may impact health-related quality of life. This prospective study sought to evaluate the impact of neoadjuvant relugolix on health-related quality of life in prostate cancer patients prior to the start of prostate RT. Methods: Patients treated at Georgetown between May 2021 and August 2023 with neoadjuvant relugolix (at least 2 months prior to RT) per an institutional protocol were included in the study (IRB 12-1775). The 5-item EQ-5D-3L, a validated questionnaire that assesses the patient-reported health status outcome, was collected for each patient at baseline (before relugolix initiation) and one hour prior to RT initiation. EQ VAS Score Overall ranges from 0-100 with a higher score indicating better quality of life. Individual items including mobility, self-care, usual activities, pain/discomfort, and anxiety/depression were scored on a three-point scale from 1 (No problems) to 3 (Extreme). To examine changes before and after relugolix treatment, McNemar’s test and paired samples t-test were used. Minimally important difference (MID) calculated by 0.5 of standard deviation at baseline was used to examine clinical significance. Results: Of 79 patients, the median age was 73 years, and 42% were non-white. Patients initiated relugolix at a median of 4 months prior to questionnaire administration (IQR: 3.9-5.4), at which most (95%) patients achieved castration (≤ 50 ng/dL). The VAS Score Overall was significantly higher at baseline (Mean ± SD: 83 ± 10) than the paired score at the start of RT (80 ± 14, p = 0.01). This change was not clinically significant. There were no statistically or clinically significant differences in any of the 5 individual items. Conclusions: Neoadjuvant relugolix prior to prostate radiation therapy did not clinically significantly affect patient-reported quality of life. Also, there was no statistically significant decrease in each of the 5 individualized items evaluating health-related quality of life. Future studies should focus on comparing it to GnRH agonist-induced change in quality of life. [Table: see text]

Clonal hematopoiesis of indeterminate potential (CHIP) and cardiovascular toxicity from androgen deprivation therapy in men with prostate cancer.

312 Background: Androgen deprivation therapy (ADT) with agonists of the gonadotropin releasing hormone (GnRH) receptor (e.g. leuprolide) is associated with coronary artery disease and major adverse cardiovascular (CV) events. CHIP, an age-related expanded somatic blood cell clone without other hematologic abnormalities, is associated with inflammation and accelerated atherosclerosis. Whether CHIP is associated with adverse CV outcomes in patients receiving ADT is unknown. Methods: Twenty-five men with localized prostate cancer pursuing radiotherapy plus ≥ 6 months of leuprolide were enrolled on a prospective biorepository. Using pre-treatment blood samples, whole exome sequencing libraries were generated; identified variants were filtered to retain &lt;1% MAF variants found amongst the three most common CHIP genes ( DNMT3A, TET2, ASXL1). Pre-treatment and 6-month blood samples from each patient subsequently were analyzed using a commercially available, validated 4-protein risk score that is predictive of 4-year major adverse CV events (Prevencio Inc HART CVE, Seattle WA). Multivariable logistic regression measured the association of CHIP with increased CV risk after initiation of leuprolide, defined as a clinically significant rise in 4-protein risk score at six months compared with baseline. Results: Median age was 70 years (IQR 65-76), 10 men (40%) were Black, and 4 men (16%) had a history of myocardial infarction. CHIP gene variants were found in 7 men (28%). Amongst the men with CHIP variants, 6 (85.7%) were Black. Amongst the entire cohort, 11/25 (44%) men had a clinically significant rise in CV risk score after six months of ADT. These men, compared with those who did not experience a rise in CV risk, were more often Black (72.7% versus 14.3%), on anti-hypertensive medication (72.7% versus 14.3%), and had higher baseline LDL cholesterol level (median 98 versus 81 mg/dL). On univariate analysis, harboring ≥1 CHIP variant was associated with a significantly increased odds of having an elevated CV risk score after 6 months of ADT. On multivariable analysis, after adjusting for race, anti-hypertensive medication use, and baseline LDL cholesterol, harboring ≥1 CHIP variant was associated with increased odds of having an elevated CV risk score after 6 months of ADT (adjusted OR 1.44, 95% CI 0.88-1.83), which did not meet statistical significance but limited by small sample size. Conclusions: Six months of GnRH-agonist leuprolide resulted in a rise in CV risk score in 44% of this cohort. CHIP variants, identified in 28% of this cohort, was associated with increased odds of experiencing a rise in CV risk score. Notably, Black men were more likely to harbor CHIP and experience increased CV risk after 6 months of leuprolide, respectively. Larger studies are underway to determine if CHIP variants may serve as a biomarker of ADT-induced CV risk, especially in older Black men.

GnRHr, LHr, and Vg gene expression levels and ovarian development of G5 transgenic mutiara female catfish (Clarias gariepinus) after exposure photoperiod induction

This study aimed to determine the relative expression ratios of the genes gonadotrophin-releasing hormone receptor (GnRHr), luteinizing hormone receptor (LHr), vitellogenin (Vg) and β-actin genes as expression control internal of the G5 fish using real-time PCR in a photoperiod experiment with designed treatments (A: 8L-16D; B: 12L-12D; C: 16L-8D for transgenic fish; and A*: 8L-16D; B*: 12L-12D; C*: 16L-8D for nontransgenic fish) for 60 days of rearing period. Ovary maturation was evaluated in G5 transgenic mutiara catfish during different photoperiod induction. A short photoperiod (8L-16D) induced an high expression of GnRHr, LHr, and Vg genes (mean, 4.42 ± 0.53, 5.63 ± 0.42, and 6.67 ± 0.31, respectively), indicating the role of dark cycle in increasing the gene expressions involved in ovarian maturation of G5 transgenic mutiara catfish. The lowest GnRHr, LHr, and Vg gene expression levels were found in nontransgenic fish (C*) (mean, 1.27 ± 0.13, 1.38 ± 0.24, and 2.42 ± 0.33, respectively). The exposure of transgenic fish (CgGH insert content) to a long photoperiod (16L-8D) resulted in lower expression levels of GnRHr, LHr, and Vg (mean, 2.31 ± 0.27, 2.34 ± 0.25, and 4.49 ± 0.30, respectively) and lower levels of hormones Vg and E2 (mean, 295.16 ± 21.71 μg/mL and 0.25 ± 0.03 ng/mL, respectively) and in non-transgenic fish (mean, 163.54 µg/mL and 0.14 ng/mL, respectively). Short photoperiods (8L-16D and 12l-12D) led to oocyte maturation and higher GSI values (mean, 12.24 ± 0.53 and 10.24 ± 0.38, respectively) compared to long photoperiods (16L-8D). Conversely, a long photoperiod led to decreased GnRHr, LHr, and Vg expression levels, and Vg and E2 hormone levels, leading to the growth of immature oocytes and decreased GSI (mean, 3.93 ± 0.29) in nontransgenic fish. The presence of CgGH in G5 transgenic mutiara female catfish can maintain the growth of primary oocytes to secondary oocytes during the 16L-8D photoperiod induction.

The effect of gonadotropin-inhibitory hormone on steroidogenesis and spermatogenesis by acting through the hypothalamic-pituitary-testis axis in mice.

Gonadotropin inhibitory hormone (GnIH) is essential for regulating the reproduction of mammals and inhibiting testicular activities in mice. This study aimed to explore the mechanism of GnIH on spermatogenesis and steroidogenesis by acting through the hypothalamus-pituitary-testis axis of mice. Mice were subcutaneously injected with different doses of GnIH (1 μg/150 μL, 3 μg/150 μL, 6 μg/150 μL, 150 μL saline, twice daily) for 11 days. Subsequently, luteinizing hormone (LH), testosterone (T), and inhibin B (INH B) levels of peripheral blood were determined, and the expression of GnRH synthesis-related genes (GnRH-1, Kiss-1, NPY) and gonadotropin synthesis-related genes (FSH β, LH β, GnRH receptor) in the hypothalamus and pituitary gland were respectively detected. Additionally, the expression of steroidogenesis-related genes/proteins (P450scc, StAR and 3β-HSD) and spermatogenesis-related proteins/genes including LH receptor (LHR), androgen receptor (AR), heat shock factor-2 (HSF-2) and INH B were analyzed using western blot and q-PCR. Results showed that GnIH treatment significantly reduced the concentration of LH in the peripheral blood. Further analysis revealed that GnIH treatment markedly reduced the expression of GnRHImRNA and Kiss-1 mRNA in the hypothalamus, and mRNA levels of FSH β, LH β, and GnRHR genes in the pituitary. We also observed that GnIH treatment significantly decreased T levels and expression of the P450scc, StAR, and 3β-HSD proteins in the testis. Furthermore, GnIH treatment down-regulated LHR, AR proteins, and HSF-2 gene in the testis. Importantly, the INH B concentration of and INH βb mRNA levels significantly declined following GnIH treatment. Additionally, GnIH treatment may induce germ cell apoptosis in the testis of mice. In conclusion, GnIH may suppress spermatogenesis and steroidogenesis by acting through the hypothalamus-pituitary-testis axis in mice.

Functional GnRH receptor signaling regulates striatal cholinergic neurons in neonatal but not in adult mice.

Reproduction in mammals is controlled by hypothalamic gonadotropin-releasing hormone (GnRH) neurons. Recent studies from our laboratory established that the basal ganglia of the human brain contain additional large populations of GnRH synthesizing neurons which are absent in adult mice. Such extrahypothalamic GnRH neurons mostly occur in the putamen where they correspond to subsets of the striatal cholinergic interneurons (ChINs) and express GnRHR autoreceptors. In an effort to establish a mouse model for functional studies of striatal GnRH/GnRHR signaling, we carried out electrophysiological experiments on acute brain slices from male transgenic mice. Using PN4-7 neonatal mice, half of striatal ChINs responded with transient hyperpolarization and decreased firing rate to 1.2 µM GnRH, whereas medium spiny projection neurons remained unaffected. GnRH acted on its specific receptor because no response was observed in the presence of the GnRHR antagonist Antide. Addition of the membrane-impermeable G protein-coupled receptor inhibitor GDP-β-S to the internal electrode solution eliminated the effect of GnRH. Further, GnRH was able to inhibit ChINs in presence of tetrodotoxin which blocked action potential mediated events. Collectively, these data indicated that the receptor underlying the effects of GnRH in neonatal mice is localized within ChINs. GnRH responsiveness of ChINs was transient and entirely disappeared in adult mice. These results raise the possibility to use neonatal transgenic mice as a functional model to investigate the role of GnRH/GnRHR signaling discovered earlier in adult human ChINs.

Isothiazolinone Disrupts Reproductive Endocrinology by Targeting the G-Protein-Coupled Receptor Signaling.

The unintended exposure of humans and animals to isothiazolinones has led to an increasing concern regarding their health hazards. Isothiazolinones were previously found to disrupt reproductive endocrine homeostasis. However, the long-term reproductive toxicity and underlying mechanism remain unclear. In this study, life-cycle exposure of medaka to dichlorocthylisothiazolinone (DCOIT), a representative isothiazolinone, significantly stimulated the gonadotropin releasing hormone receptor (GnRHR)-mediated synthesis of follicle stimulating hormone and luteinizing hormone in the brain. Chem-Seq and proteome analyses revealed disturbances in the G-protein-coupled receptor, MAPK, and Ca2+ signaling cascades by DCOIT. The G protein αi subunit was identified as the binding target of DCOIT. Gαi bound by DCOIT had an enhanced affinity for the mitochondrial calcium uniporter, consequently changing Ca2+ subcellular compartmentalization. Stimulation of Ca2+ release from the endoplasmic reticulum and blockage of Ca2+ uptake into the mitochondria resulted in a considerably higher cytoplasmic Ca2+ concentration, which then activated the phosphorylation of MEK and ERK to dysregulate hormone synthesis. Overall, by comprehensively integrating in vivo, ex vivo, in silico, and in vitro evidence, this study proposes a new mode of endocrine disrupting toxicity based on isothiazolinones, which is expected to aid the risk assessment of the chemical library and favor the mechanism-driven design of safer alternatives.

Sequence identification and expression characterization of leptin in the spotted scat, Scatophagus argus.

Scatophagus argus is an important marine culture fish in South and South-East Asia, including Southeast coastal areas of China. Artificial propagation technology for S. argus is not optimum; thus further studies on its reproduction biology are required. Although previous studies have shown that leptin (Lep) can regulate fish reproduction, the role of lep genes in S. argus is unknown. Herein, in silico analysis showed that S. argus has two lep genes (lepa and lepb). Protein 3D-structure prediction showed that Lepa has four α-helices (similar to mammals), while Lepb only has three. Tissue distribution analysis showed that lepa is highly expressed in the liver, whereas lepb was not detected in any tissue. Notably, lepr was expressed in all tissues. Lepa mRNA expression levels in the liver and serum Lep, estradiol (E2) and vitellogenin (Vtg) levels of female fish were significantly higher in ovaries at stage IV than in ovaries at stage II. Serum E2 levels were significantly positively correlated with Vtg levels in female fish at different development stages, while serum E2 was not correlated with Lep levels. Consistently, in vitro incubation of the liver with E2 significantly up-regulated vtga, while it did not affect lepa expression. Recombinant Lep (10nM) significantly up-regulated chicken gonadotropin-releasing hormone (cGnRH/GnRH-II) in the hypothalamus and GnRH receptor (GnRHR) and luteinizing hormone beta (Lhb) in the pituitary. These results suggest that lepa regulates female reproduction in S. argus.

High Population Frequency of GNRHR p.Q106R in Malta: An Evaluation of Fertility and Hormone Profiles in Heterozygotes.

The gonadotropin-releasing hormone receptor variant GNRHR p.Q106R (rs104893836) in homozygosity, compound heterozygosity, or single heterozygosity is often reported as the causative variant in idiopathic hypogonadotropic hypogonadism (IHH) patients with GnRH deficiency. Genotyping of a Maltese newborn cord-blood collection yielded a minor allele frequency (MAF) 10 times higher (MAF = 0.029; n = 493) than that of the global population (MAF = 0.003). To determine whether GNRHR p.Q106R in heterozygosity influences profiles of endogenous hormones belonging to the hypothalamic-pituitary axis and the onset of puberty and fertility in adult men (n = 739) and women (n = 239). Analysis of questionnaire data relating to puberty and fertility, genotyping of the GNRHR p.Q106R variant, and hormone profiling of a highly phenotyped Maltese adult cohort from the Maltese Acute Myocardial Infarction Study. Out of 978 adults, 43 GNRHR p.Q106R heterozygotes (26 men and 17 women) were identified. Hormone levels and fertility for all heterozygotes are within normal parameters except for TSH, which was lower in men 50 years or older. Hormone data and baseline fertility characteristics of GNRHR p.Q106R heterozygotes are comparable to those of homozygous wild-type individuals who have no reproductive problems. The heterozygous genotype alone does not impair the levels of investigated gonadotropins and sex steroid hormones or affect fertility. GNRHR p.Q106R heterozygotes who exhibit IHH characteristics must have at least another variant, probably in a different IHH gene, that drives pathogenicity. We also conclude that GNRHR p.Q106R is likely a founder variant due to its overrepresentation and prevalence in the island population of Malta.

Dapagliflozin Ameliorates Ovulation Disorders via Attenuating Activated Microglia-Mediated Hypothalamic Inflammation in HFD-Fed Mice

Introduction: Sodium-glucose cotransporter 2 inhibitors (SGLT2is) have shown neuroprotective effects in obese mice. However, whether SGLT2i can ameliorate high-fat diet (HFD)-related ovulation disorders remains unknown. The aim of this research was to investigate whether dapagliflozin improves HFD-induced ovulatory dysfunction by attenuating microglia-mediated hypothalamic inflammation. Methods: C57BL/6J female mice fed HFD were treated with dapagliflozin (1 mg/kg) for 22 weeks. Plasma insulin, leptin, luteinizing hormone (LH), estradiol (E2), and IL-1β levels were also tested. Microglial morphology, cell numbers, and SGLT2 expression were evaluated using immunofluorescence. The expression of IL-1β, NLRP3, kisspeptin, gonadotropin-releasing hormone (GnRH), SGLT2, insulin, and leptin receptors in the hypothalamus was determined using immunohistochemical staining. We also examined the effects of dapagliflozin on glucose metabolism and the release of inflammatory factor in palmitic acid (PA)-treated HMC3 cells. Results: As expected, dapagliflozin improved HFD-induced metabolic disturbances, peripheral versus central insulin and leptin resistance and also restored the regular estrous cycle. Furthermore, dapagliflozin blunted microglia activation, NLRP3 inflammasome priming, hypothalamic inflammation, and increased the expression of GnRH and kisspeptin at proestrus in the hypothalamus. Additionally, dapagliflozin markedly reduced IL-6 and NO release and fat accumulation, decreased lactic acid production and glucose consumption, and inhibited mammalian target of rapamycin (mTOR) and hexokinase 2 (HK2) expression in PA-treated HMC3 cells. These effects suggest that dapagliflozin reduced the mTOR/HK2-mediated aerobic glycolysis. Conclusions: Dapagliflozin improved HFD-related ovulation disorders by regulating glucose metabolism through mTOR/HK2 signaling and attenuating microglia-mediated hypothalamic inflammation. These results validate the novel role for the neuroprotection of SGLT2i in HFD-induced obesity and ovulation disorders.

Electron microscopic changes in interstitial endocrinocytes of rats testicles during administration of triptorellin for 365 days

Triptorelin is a gonadotropin-releasing hormone agonist that is a potent inhibitor of testosterone (in men) and estrogen (in women) synthesis and is used to treat advanced prostate cancer. Studies of the mechanisms of regulation and synthesis of testosterone formation in testicular interstitial cells demonstrate multiple endogenous targets that can increase testosterone biosynthesis, which may moderate the effects of testosterone depletion. Triptorelin, a synthetic analog of the neurohormone gonadoliberin, suppresses the expression of the GnRH receptor in the pituitary gland, but does not change the functioning of the pituitary-testicular complex. The purpose of the work is to study the electron microscopic changes in the interstitial endocrinocytes of the testes of rats after the administration of triptorelin for 365 days. The experiment was conducted on 35 sexually mature male white rats. The rats were divided into 2 groups: the control group (I) was injected with a physiological solution, the II group with central deprivation of the synthesis of luteinizing hormone was injected subcutaneously with triptorelin at a dose of 0.3 mg of the active substance per kg of the rat's body weight. The study of the interstitial space in the testicles of white rats showed that long-term administration of triptorelin causes hormonal dysregulation of the hypothalamus-pituitary-testis system, which leads to quantitative and qualitative changes in the endocrine cells of the interstitial space of the testis, which is confirmed by electron microscopic changes in subcellular structures. The maximum effect of triptorelin is determined from the 180th day of observation, which is characterized by an increase in degenerative changes in endocrinocytes, and the detection of Reinke crystals in the cytoplasm of interstitial endocrinocytes from the 270th day of observation.

Identification of a valuable gene network for the diagnosis and treatment of non-obstructive azoospermia: in-silico analyses – experimental research

Introduction: Non-obstructive azoospermia (NOA) is an etiology of infertility in men. NOA may have various classifications; however, hypogonadotropic hypogonadism can be regarded as a class of NOA associated with genetic factors. Former studies have shown that noncoding RNA (ncRNA) plays an essential role in NOA incidence, but few studies have been performed on the NOA-related ncRNA interaction network. In the current study, genes, NOA-related microRNA (miRNA), and circular RNA (circRNA) were found by bioinformatics methods to offer a new perspective on NOA treatment. Methods: The gonadotropin-releasing hormone receptor (GnRHR)-related protein–protein interaction (PPI) network was extracted by searching in ‘string-database’. GO, KEGG, and Enrichr databases were used to identify pathways, molecular function, and biological processing. Four databases, including TargetScan, mirDIP, miRmap, and miRWalk, were used to extract miRNAs. At last, the circ2GO, circBase, and literature were used to identify circRNAs and their genes. Results: The current study identified the four proteins associated with the GnRHR signaling; eight shared miRNAs that affect the expression of found proteins and 25 circRNAs and their origin genes that regulate the miRNAs’ function. Conclusion: The two miRNAs, hsa-miR-134-3p and hsa-miR-513C-3p, the three genes, VCAN, NFATC3, and PRDM5, and their associated circRNAs can perform as a valuable gene network in the diagnosis and treatment of NOA pathogenesis.

Therapeutic effects of melatonin in female mice with central precocious puberty by regulating the hypothalamic Kiss-1/Kiss1R system

In recent years, central precocious puberty (CPP) in children is becoming more common, which seriously affects their physical and psychological health and requires finding a safe and effective treatment method. The aim of this study was to investigate the therapeutic effect of melatonin on CPP. A CPP model was established by subcutaneous injection of 300 micrograms of danazol into 5-day-old female mice, followed by treatment with melatonin and leuprolide. The vaginal opening was checked daily. Mice were weighed, gonads were weighed, gonadal index was calculated, and gonadal development was observed by hematoxylin and eosin (HE) staining. Serum follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2) levels were measured by ELISA. By using RT-PCR and Western blotting, the mRNA and protein expression of the hypothalamus Kiss-1, Kiss-1 receptor (Kiss1R), gonadotropin-releasing hormone (GnRH), and pituitary GnRH receptor (GnRHR) were identified. The results showed that melatonin delayed vaginal opening time and reduced body weight, gonadal weight and indices in female CPP mice. Melatonin treatment prevents uterine wall thickening and ovarian luteinization in female CPP mice. Melatonin treatment reduces serum concentrations of FSH, LH, and E2 in female CPP mice. Melatonin suppressed the expressions of Kiss-1, Kiss1R and GnRH in the hypothalamus, and the expression of GnRHR in the pituitary of the female CPP mice. Our results suggest that melatonin can inhibit the hypothalamic-pituitary-gonadal (HPG) axis by down-regulating the Kiss-1/Kiss1R system, thereby treating CPP in female mice.

Identification of key miRNAs as regulatory biomarkers of gonadotropins leading to infertility in males

Introduction. Infertility is a highly fatal reproductive system disorder that affects the ability of a couple to reproduce. Over the past decades, a drastic uplift has been recorded in infertility cases among males ranging from 20 to 70 % indicating spermatogenesis impairment.Aim: to identify key microRNAs (miRNAs) as regulatory biomarkers of gonadotropins involved in dysregulation of fertility-related genes to propose potential therapeutic strategies that would combat the action of oncogenic miRNAs (oncomiRs).Materials and Methods. Interaction analysis was performed between miRNAs and fertility-related genes namely luteinizing hormone choriogonadotropin receptor (LHCGR), gonadotropin-releasing hormone receptor (GnRHR), follicle-stimulating hormone receptor (FSHR) and cystic fibrosis transmembrane conductance regulator (CFTR) to identify key miRNAs as regulatory biomarkers of gonadotropins leading to infertility in males.Results. A total of 10, 13, 31 and 18 strong and potential binding sites were predicted for miRNAs-LHCGR, miRNAs-GnRHR, miRNAs-FSHR, and miRNAs-CFTR respectively employing miRWalk (comprehensive genetic database including miRNA targets) followed by identification of 6, 18, 55 and 17 significant interactions through RNA22. Subsequently shortlisted miRNAs and messenger RNA (mRNA) regions were subjected to Vfold-Pipeline and RNAComposer individually for 3D structure prediction. Additionally molecular docking was carried out between miRNAs and mRNAs models that discovered potential and stable interactions elucidating miR-6880-FSHR(R2) as a highly stable complex with least binding affinity (-566.3) and high confidence score (0.999).Conclusion. Hence this study proposes key oncomiRs as a diagnostic biomarker and therapeutic target to bring about a promising treatment strategy against male factor infertility. However wet lab investigations are required for further validations of proposed study.