Genome sequencing reveals novel causative structural and single nucleotide variants in Pakistani families with congenital hypogonadotropic hypogonadism.

BACKGROUND/OBJECTIVES: This study aims to elucidate the genetic causes of congenital hypogonadotropic hypogonadism (CHH), a rare genetic disorder resulting in GnRH deficiency, in six families from Pakistan. METHODS: Eighteen DNA samples from six families underwent genome sequencing followed by standard evaluation for pathogenic single nucleotide variants (SNVs) and small indels. All families were subsequently analyzed for pathogenic copy number variants (CNVs) using CoverageMaster. RESULTS: Novel pathogenic homozygous SNVs in known CHH genes were identified in four families: two families with variants in GNRHR, and two others harboring KISS1R variants. Subsequent investigation of CNVs in the remaining two families identified novel unique large deletions in ANOS1. CONCLUSION: A combined, systematic analysis of single nucleotide and CNVs helps to improve the diagnostic yield for variants in patients with CHH.

GV1001 modulates neuroinflammation and improves memory and behavior through the activation of gonadotropin-releasing hormone receptors in a triple transgenic Alzheimer's disease mouse model.

GV1001 protects neural cells from amyloid-ß (Aß) toxicity and other stressors in in vitro studies and demonstrates clinically beneficial effects in patients with moderate to severe Alzheimer's disease (AD). Here, we investigated the protective effects and mechanism of action of GV1001 in triple transgenic AD (3xTg-AD) mice. We found that GV1001 improved memory and cognition in middle- and old-aged 3xTg-AD mice. Additionally, it reduced Aß oligomer and phospho-tau (Ser202 and Thr205) levels in the brain, and mitigated neuroinflammation by promoting a neuroprotective microglial and astrocyte phenotype while diminishing the neurotoxic ones. In vitro, GV1001 bound to gonadotropin releasing hormone receptors (GnRHRs) with high affinity. Levels of cyclic adenosine monophosphate, a direct downstream effector of activated GnRHRs, increased after GV1001 treatment. Furthermore, inhibition of GnRHRs blocked GV1001-induced effects. Thus, GV1001 might improve cognitive and memory functions of 3xTg-AD mice by suppressing neuroinflammation and reducing Aß oligomers levels and phospho-tau by activating GnRHRs and their downstream signaling pathways.

Lipid-Based Nanocarrier by Targeting with LHRH Peptide: A Promising Approach for Prostate Cancer Radio-Imaging and Therapy.

Prostate cancer is a prevalently detected malignancy with a dismal prognosis. Luteinizing-hormone-releasing-hormone (LHRH) receptors are overexpressed in such cancer cells, to which the LHRH-decapeptide can specifically bind. A lipid-polyethylene glycol-conjugated new LHRH-decapeptide analogue (D-P-HLH) was synthesized and characterized. D-P-HLH-coated and anticancer drug doxorubicin (DX)-loaded solid lipid nanoparticles (F-DX-SLN) were formulated by the cold homogenization technique and characterized by Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, differential scanning calorimetry, dynamic light scattering, electron microscopy, entrapment efficiency, and drug-release profile studies. F-DX-SLN allows site-specific DX delivery by reducing the side effects of chemotherapy. Cancer cells could precisely take up F-DX-SLN by targeting specific receptors, boosting the cytotoxicity at the tumor site. The efficacy of F-DX-SLN on PC3/SKBR3 cells by the MTT assay revealed that F-DX-SLN was more cytotoxic than DX and/or DX-SLN. Flow cytometry and confocal microscopic studies further support F-DX-SLNs' increased intracellular absorption capability in targeting LHRH overexpressed cancer cells. F-DX-SLN ensured high apoptotic potential, noticeably larger mitochondrial transmembrane depolarization action, as well as the activation of caspases, a longer half-life, and greater plasma concentration. F-DX-SLN/DX-SLN was radiolabeled with technetium-99m; scintigraphic imaging studies established its tumor selectivity in PC3 tumor-bearing nude mice. The efficacy of the formulations in cancer treatment, in vivo therapeutic efficacy tests, and histopathological studies were also conducted. Results clearly indicate that F-DX-SLN exhibits sustained and superior targeted administration of anticancer drugs, thus opening up the possibility of a drug delivery system with precise control and targeting effects. F-DX-SLN could also provide a nanotheranostic approach with improved efficacy for prostate cancer therapy.

Unraveling Hypothalamus-Pituitary dysregulation: Hypergonadotropism in F1 progeny due to prenatal exposure to hexavalent chromium.

The endocrine disruptor hexavalent chromium [Cr(VI)] is a proven reproductive toxicant. We recently demonstrated that prenatal Cr(VI) exposure causes testicular resistance to gonadotropins, resulting in hypergonadotropic hypoandrogenism in F1 rats. However, the mechanism driving hypergonadotropism in F1 rats exposed to Cr(VI) prenatally remains an enigma. Therefore, we hypothesized that 'Prenatal Cr(VI) exposure may disrupt steroid hormones-mediated negative feedback regulation of the hypothalamic GnRH, and its receptor in the pituitary of F1 rats, leading to hypergonadotropism.' We administered potassium dichromate (50, 100, or 200 mg/L) to pregnant rats through drinking water between days 9 and 14, and their male F1 offspring were euthanized at 60 days of age. Prenatal Cr(VI) exposure in F1 rats resulted in the accumulation of Cr in the hypothalamus and pituitary. Western blot detected decreased hypothalamic GnRH, Kisspeptin1, and its receptor GPR54, along with diminished ERα, AR, aromatase, and 5α reductase, and GnRH regulatory transcription factors Pit-1 and GATA-4 proteins. Immunohistochemical studies revealed increased immunopositivity of GnRH receptor, AR, 5α reductase, ERα, ERß, and aromatase proteins in the pituitary, whereas decreased Kisspeptin1, GPR54, and inhibin ß. Our findings imply that Cr(VI) exposure during the prenatal period disrupts the hypothalamic Kisspeptin-GPR54-Pit-1/GATA4-GnRH network, boosting the pituitary GnRH receptor. We conclude that prenatal exposure to Cr(VI) alters GnRH expression in the hypothalamus and its receptor in the pituitary of F1 progeny through interfering with the negative feedback effect of androgens and estrogens.

Direct evidence that KNDy neurons maintain gonadotropin pulses and folliculogenesis as the GnRH pulse generator.

The gonadotropin-releasing hormone (GnRH) pulse is fundamental for mammalian reproduction: GnRH pulse regimens are needed as therapies for infertile women as continuous GnRH treatment paradoxically inhibits gonadotropin release. Circumstantial evidence suggests that the hypothalamic arcuate KNDy neurons expressing kisspeptin (encoded by Kiss1), neurokinin B (encoded by Tac3), and dynorphin A serve as a GnRH pulse generator; however, no direct evidence is currently available. Here, we show that rescuing >20% KNDy neurons by transfecting Kiss1 inside arcuate Tac3 neurons, but not outside of these neurons, recovered folliculogenesis and luteinizing hormone (LH) pulses, an indicator of GnRH pulses, in female global Kiss1 knockout (KO) rats and that >90% conditional arcuate Kiss1 KO in newly generated Kiss1-floxed rats completely suppressed LH pulses. These results first provide direct evidence that KNDy neurons are the GnRH pulse generator, and at least 20% of KNDy neurons are sufficient to maintain folliculogenesis via generating GnRH/gonadotropin pulses.

Does the activation of sea bass GnIH receptor modulate GnRH receptor signaling?

Previous studies have revealed the stimulatory and inhibitory actions of gonadotropin-releasing hormone (GnRH) and gonadotropin-inhibitory hormone (GnIH) on the control of reproduction in European sea bass (Dicentrarchus labrax) and other vertebrates, respectively. However, information on the possible interactions between GnRH and GnIH on cell signaling is sparse in vertebrates. In the current study, we investigated if activation of sea bass GnIH receptor (GnIHR) can interfere with GnRH receptor II-1a (GnRHR-II-1a) involving the PKA pathway. Our results showed that GnIH and GnRH functioned via their cognate receptors, respectively. However, it appears that neither GnIH1 nor GnIH2 can block GnRH/GnRHR-II-1a-induced PKA signaling in sea bass. This is the first study to examine the potential interactions of GnIH with GnRH receptor signaling in teleosts. Further research seems necessary to shed light on unknown interactions in other signaling pathways and other GnIH/GnRH receptors involved in the physiological functions of these two relevant neuropeptides, not only in sea bass but also in other species.

Cytotoxic Activity of Novel GnRH Analogs Conjugated with Mitoxantrone in Ovarian Cancer Cells.

The gonadotropin-releasing hormone (GnRH) receptor (GnRH-R) is highly expressed in ovarian cancer cells (OCC), and it is an important molecular target for cancer therapeutics. To develop a new class of drugs targeting OCC, we designed and synthesized Con-3 and Con-7 which are novel high-affinity GnRH-R agonists, covalently coupled through a disulfide bond to the DNA synthesis inhibitor mitoxantrone. We hypothesized that Con-3 and Con-7 binding to the GnRH-R of OCC would expose the conjugated mitoxantrone to the cellular thioredoxin, which reduces the disulfide bond of Con-3 and Con-7. The subsequent release of mitoxantrone leads to its intracellular accumulation, thus exerting its cytotoxic effects. To test this hypothesis, we determined the cytotoxic effects of Con-3 and Con-7 using the SKOV-3 human OCC. Treatment with Con-3 and Con-7, but not with their unconjugated GnRH counterparts, resulted in the accumulation of mitoxantrone within the SKOV-3 cells, increased their apoptosis, and reduced their proliferation, in a dose- and time-dependent manner, with half-maximal inhibitory concentrations of 0.6-0.9 µM. It is concluded that Con-3 and Con-7 act as cytotoxic "prodrugs" in which mitoxantrone is delivered in a GnRH-R-specific manner and constitute a new class of lead compounds for use as anticancer drugs targeting ovarian tumors.

The Effects of Human Chorionic Gonadotropin and Gonadotropin-Releasing Hormone Receptor Antagonist on Testicular Steroidogenesis in Normal and Obese Rats.

We studied the effect of a high-fat, high-carbohydrate diet (HFHCD) on basal testosterone levels in the blood and testosterone, its precursors, and expression of steroidogenic genes in the testes of rats treated with human chorionic gonadotropin (hCG, 10 IU/rat, subcutaneously, once), gonadotropin-releasing hormone receptor antagonist cetrorelix (75 µg/kg, subcutaneously, 3 days), and their combination. In HFHCD rats, no obvious signs of androgen deficiency were observed and the response of the testes to hCG stimulation was preserved. Unlike control rats (normal diet), the expression of the luteinizing hormone receptor gene in these rats did not change in response to hCG stimulation and cetrorelix administration; they also showed a paradoxical, more pronounced response to hCG administration under conditions of suppression of the gonadotropin secretion by cetrorelix. This suggests that the etiology and pathogenesis of obesity may have different effects on the hormonal status of the male reproductive system.

[Regulating effect of Gegen Decoction on hypothalamic-pituitary-ovarian axis in mice with primary dysmenorrhea].

This study aimed to explore the regulating effect of Gegen Decoction(GGD) on the hypothalamic-pituitary-ovarian axis(HPOA) dysfunction in the mouse model of primary dysmenorrhea(PD). The mouse model of PD with periodic characteristics was established by administration of estradiol benzoate and oxytocin. Mice were randomized into control, model, GGD, and ibuprofen groups. The writhing response, hypothalamus index, pituitary index, ovary index, and uterus index were observed and determined. The serum levels of prostaglandin F_(2α)(PGF_(2α)), gonadotropin-releasing hormone(GnRH), follicle-stimulating hormone(FSH), luteinizing hormone(LH), and estrogen(E_2) levels were measured by ELISA kits. Western blot and qPCR were employed to determine the protein and mRNA levels, respectively, of gonadotropin-releasing hormone receptor(GnRH-R) in the pituitary tissue, follicle-stimulating hormone receptor(FSHR) and luteinizing hormone receptor(LHR) in the ovarian tissue, and estrogen receptor(ER) in the uterine tissue. The results showed that the writhing response, serum levels of PGF_(2α), GnRH, FSH, LH, and E_2, ovarian and uterine indexes, the protein and mRNA levels of GnRH-R in the pituitary tissue, FSHR and LHR in the ovarian tissue, and ER in the uterine tissue were significantly increased in the model group compared with those in the control group. GGD inhibited the writhing response, reduced the serum levels of PGF_(2α), GnRH, FSH, LH, and E_2, decreased the ovarian and uterine indexes, and down-regulated the protein and mRNA levels of GnRH-R in the pituitary tissue, FSHR and LHR in the ovarian tissue, and ER in the uterine tissue. The data suggested that GGD can regulate the HPOA and inhibit E_2 generation in the mice experiencing recurrent PD by down-regulating the expression of proteins and genes related to HPOA axis, thus exerting the therapeutic effect on PD.

Linzagolix with and without hormonal add-back therapy for the treatment of symptomatic uterine fibroids: two randomised, placebo-controlled, phase 3 trials.

BACKGROUND: Uterine fibroids are common non-cancerous neoplasm that cause heavy menstrual bleeding and other signs. Linzagolix is an oral gonadotropin-releasing hormone receptor antagonist taken once per day that dose-dependently suppresses gonadal steroids and might reduce uterine-fibroid-associated signs. Two phase 3 trials were conducted to confirm the efficacy and safety of linzagolix at full-suppression (200 mg) and partial-suppression (100 mg) doses with or without hormonal add-back therapy (1 mg oestradiol and 0·5 mg norethisterone acetate) compared with placebo for the treatment of symptomatic uterine fibroids. METHODS: PRIMROSE 1 and PRIMROSE 2 were identical 52-week, randomised, parallel, double-blind, placebo-controlled, phase 3 trials conducted at clinics in the USA (PRIMROSE 1) and Europe and the USA (PRIMROSE 2). Eligible women with uterine fibroid-associated heavy menstrual bleeding (menstrual blood loss >80 mL per cycle) were randomly assigned in a 1:1:1:1:1 ratio to one of five masked treatments: (1) placebo, (2) 100 mg linzagolix per day alone, (3) 100 mg linzagolix per day with once-per-day hormonal add-back therapy (1 mg oestradiol and 0·5 mg norethisterone acetate), (4) 200 mg linzagolix per day alone, or (5) 200 mg linzagolix per day with once-per-day hormonal add-back therapy (1 mg oestradiol and 0·5 mg norethisterone acetate). The primary endpoint was a response (menstrual blood loss ≤80 mL and ≥50% reduction from baseline) at 24 weeks in women who received at least one dose of treatment and did not meet any exclusion criteria based on predosing assessments. These trials are registered with ClinicalTrials.gov (NCT03070899 and NCT03070951). The trials have been completed. FINDINGS: Between May, 2017, and October, 2020, in PRIMROSE 1, 574 women were enrolled, of which 48 discontinued and 15 were excluded; therefore, 511 women were included in the full analysis set; and in PRIMROSE 2, 535 women were enrolled, of which 24 did not receive the study drug and ten women were excluded from the study, resulting in 501 women being included in the full analysis set. In both trials, a significantly higher proportion of women had a reduction in heavy menstrual bleeding in all linzagolix (with or without add-back therapy) treatment groups compared with the placebo group (p≤0·003). In PRIMROSE 1, the response rates were 56·4% (95% CI 45·8-66·6%) in the 100 mg group, 66·4% (56·6-75·2%) in the 100 mg plus add-back therapy group, 71·4% (61·8-79·8%) in the 200 mg group, and 75·5% (66·0-83·5%) in the 200 mg plus add-back therapy group, compared with 35·0% (25·8-45·0%) in the placebo group. In PRIMROSE 2, the response rates were 56·7% (46·3-66·7%) in the 100 mg group, 77·2% (67·8-85·0%) in the 100 mg plus add-back therapy group, 77·7% (68·4-85·3%) in the 200 mg group, and 93·9% (87·1-97·7%) in the 200 mg plus add-back therapy group, compared with 29·4% (20·8-39·3%) with placebo. The most common adverse events up to 24 weeks were hot flushes (35% of participants in PRIMROSE 1 and 32% in PRIMROSE 2 with linzagolix [200 mg] alone and 3-14% in all other groups). INTERPRETATION: Linzagolix (100 mg or 200 mg) with or without add-back therapy significantly reduced heavy menstrual bleeding. Partial suppression with once-per-day linzagolix (100 mg) without add-back therapy potentially provides a unique option for the chronic treatment of symptomatic uterine fibroids in women who cannot or do not want to take concomitant hormonal add-back therapy. FUNDING: ObsEva.

Safety, pharmacokinetics, and pharmacodynamics of SHR7280, an oral gonadotropin-releasing hormone receptor antagonist, in healthy men: a randomized, double-blind, placebo-controlled phase 1 study.

BACKGROUND: Gonadotropin-releasing hormone (GnRH) antagonists are a promising therapeutic approach for treating hormone-dependent prostate cancer. Currently, the mainstream GnRH antagonists are polypeptide agents administered through subcutaneous injection. In this study, we evaluated the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of SHR7280, an oral small molecule GnRH antagonist, in healthy men. METHODS: This phase 1 trial was a randomized, double-blind, placebo-controlled, and dose-ascending study. Eligible healthy men were randomized in a 4:1 ratio to receive either oral SHR7280 tablets or placebo twice daily (BID) for 14 consecutive days. The SHR7280 dose was initiated at 100 mg BID and then sequentially increased to 200, 350, 500, 600, 800, and 1000 mg BID. Safety, PK, and PD parameters were assessed. RESULTS: A total of 70 subjects were enrolled and received the assigned drug, including 56 with SHR7280 and 14 with placebo. SHR7280 was well-tolerated. The incidence of adverse events (AEs, 76.8% vs 85.7%) and treatment-related AEs (75.0% vs 85.7%), as well as the severity of AEs (moderate AEs, 1.8% vs 7.1%) were similar between the SHR7280 group and placebo group. SHR7280 was rapidly absorbed in a dose-dependent manner, with a median Tmax of each dose group ranging from 0.8 to 1.0 h on day 14 and a mean t1/2 ranging from 2.8 to 3.4 h. The PD results demonstrated that SHR7280 exhibited a rapid and dose-proportional suppression of hormones, including LH, FSH, and testosterone, with maximum suppression achieved at doses of 800 and 1000 mg BID. CONCLUSIONS: SHR7280 showed an acceptable safety profile, as well as favorable PK and PD profiles within a dose range of 100 to 1000 mg BID. This study proposes a rationale for further investigation of SHR7280 as a potential androgen deprivation therapy. TRIAL REGISTRATION: Clinical trials.gov NCT04554043; registered September 18, 2020.

AXL receptor tyrosine kinase modulates gonadotropin-releasing hormone receptor signaling.

BACKGROUND: Gonadotropin-releasing hormone (GnRH) receptors are essential for reproduction and are expressed in numerous urogenital, reproductive, and non-reproductive cancers. In addition to canonical G protein-coupled receptor signaling, GnRH receptors functionally interact with several receptor tyrosine kinases. AXL is a receptor tyrosine kinase expressed in numerous tissues as well as multiple tumors. Here we tested the hypothesis that AXL, along with its endogenous ligand Gas6, impacts GnRH receptor signaling. METHODS: We used clonal murine pituitary αT3-1 and LßT2 gonadotrope cell lines to examine the effect of AXL activation on GnRH receptor-dependent signaling outcomes. ELISA and immunofluorescence were used to observe AXL and GnRH receptor expression in αT3-1 and LßT2 cells, as well as in murine and human pituitary sections. We also used ELISA to measure changes in ERK phosphorylation, pro-MMP9 production, and release of LHß. Digital droplet PCR was used to measure the abundance of Egr-1 transcripts. A transwell migration assay was used to measure αT3-1 and LßT2 migration responses to GnRH and AXL. RESULTS: We observed AXL, along with the GnRH receptor, expression in αT3-1 and LßT2 gonadotrope cell lines, as well as in murine and human pituitary sections. Consistent with a potentiating role of AXL, Gas6 enhanced GnRH-dependent ERK phosphorylation in αT3-1 and LßT2 cells. Further, and consistent with enhanced post-transcriptional GnRH receptor responses, we found that Gas6 increased the abundance of Egr-1 transcripts. Suggesting functional significance, in LßT2 cells, Gas6/AXL signaling stimulated LHß production and enhanced GnRH receptor-dependent generation of pro-MMP9 protein and promoted cell migration. CONCLUSIONS: Altogether, these data describe a novel role for AXL as a modulator of GnRH receptor signaling. Video Abstract.

Suppressive effects of linzagolix, a novel non-peptide antagonist of gonadotropin-releasing hormone receptors, in experimental endometriosis model rats.

Endometriosis is an oestrogen-dependent disease in which endometrial-like tissue grows outside the uterus in women of reproductive age. Accordingly, control of oestradiol (E2) levels is an effective treatment for endometriosis. Because gonadotropin-releasing hormone (GnRH) is the main controller of E2 secretion, control of GnRH signalling by GnRH antagonism is an effective strategy for the treatment of sex hormone-dependent diseases such as endometriosis. The purpose of the present study was to evaluate the effects of the potent, orally available and selective GnRH antagonist linzagolix on experimental endometriosis in rats and compare them with those of dienogest, which is used clinically to treat endometriosis. Experimental endometriosis was induced in female rats at the proestrus stage of the oestrous cycle via autotransplantation of endometrial tissue into the renal subcapsular space. Linzagolix significantly decreased cyst volumes compared with the control group at doses of 50 mg/kg or more. Indeed, a suppressive effect of dienogest on cyst volume was observed only at the highest dose evaluated (1 mg/kg). The effective concentration of linzagolix, calculated as the free form of the last-observed drug concentration, was ~1 µmol/L in endometriosis model rats. The present study also reveals that linzagolix exerts a sustained inhibitory effect on E2 secretion, indicating that the suppressive effect on endometriosis cyst volumes could be attributed to its pharmacological suppression of GnRH signalling and serum E2 concentrations. Altogether, our findings indicate that linzagolix may be a useful therapeutic intervention for hormone-dependent diseases including endometriosis.

Splice variant of growth hormone-releasing hormone receptor drives esophageal squamous cell carcinoma conferring a therapeutic target.

The extrahypothalamic growth hormone-releasing hormone (GHRH) and its cognate receptors (GHRH-Rs) and splice variants are expressed in a variety of cancers. It has been shown that the pituitary type of GHRH-R (pGHRH-R) mediates the inhibition of tumor growth induced by GHRH-R antagonists. However, GHRH-R antagonists can also suppress some cancers that do not express pGHRH-R, yet the underlying mechanisms have not been determined. Here, using human esophageal squamous cell carcinoma (ESCC) as a model, we were able to reveal that SV1, a known splice variant of GHRH-R, is responsible for the inhibition induced by GHRH-R antagonist MIA-602. We demonstrated that GHRH-R splice variant 1 (SV1) is a hypoxia-driven promoter of tumor progression. Hypoxia-elevated SV1 activates a key glycolytic enzyme, muscle-type phosphofructokinase (PFKM), through the nuclear factor kappa B (NF-κB) pathway, which enhances glycolytic metabolism and promotes progression of ESCC. The malignant actions induced by the SV1-NF-κB-PFKM pathway could be reversed by MIA-602. Altogether, our studies demonstrate a mechanism by which GHRH-R antagonists target SV1. Our findings suggest that SV1 is a hypoxia-induced oncogenic promoter which can be an alternative target of GHRH-R antagonists.

Gonadotropin-Releasing Hormone Receptor (GnRHR) and Hypogonadotropic Hypogonadism.

Human sexual and reproductive development is regulated by the hypothalamic-pituitary-gonadal (HPG) axis, which is primarily controlled by the gonadotropin-releasing hormone (GnRH) acting on its receptor (GnRHR). Dysregulation of the axis leads to conditions such as congenital hypogonadotropic hypogonadism (CHH) and delayed puberty. The pathophysiology of GnRHR makes it a potential target for treatments in several reproductive diseases and in congenital adrenal hyperplasia. GnRHR belongs to the G protein-coupled receptor family and its GnRH ligand, when bound, activates several complex and tissue-specific signaling pathways. In the pituitary gonadotrope cells, it triggers the G protein subunit dissociation and initiates a cascade of events that lead to the production and secretion of the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) accompanied with the phospholipase C, inositol phosphate production, and protein kinase C activation. Pharmacologically, GnRHR can be modulated by synthetic analogues. Such analogues include the agonists, antagonists, and the pharmacoperones. The agonists stimulate the gonadotropin release and lead to receptor desensitization with prolonged use while the antagonists directly block the GnRHR and rapidly reduce the sex hormone production. Pharmacoperones include the most recent GnRHR therapeutic approaches that directly correct the misfolded GnRHRs, which are caused by genetic mutations and hold serious promise for CHH treatment. Understanding of the GnRHR's genomic and protein structure is crucial for the most appropriate assessing of the mutation impact. Such mutations in the GNRHR are linked to normosmic hypogonadotropic hypogonadism and lead to various clinical symptoms, including delayed puberty, infertility, and impaired sexual development. These mutations vary regarding their mode of inheritance and can be found in the homozygous, compound heterozygous, or in the digenic state. GnRHR expression extends beyond the pituitary gland, and is found in reproductive tissues such as ovaries, uterus, and prostate and non-reproductive tissues such as heart, muscles, liver and melanoma cells. This comprehensive review explores GnRHR's multifaceted role in human reproduction and its clinical implications for reproductive disorders.

Rational Design, Synthesis and Binding Affinity Studies of Anthraquinone Derivatives Conjugated to Gonadotropin-Releasing Hormone (GnRH) Analogues towards Selective Immunosuppression of Hormone-Dependent Cancer.

Gonadotropin-releasing hormone (GnRH) is pivotal in regulating human reproduction and fertility through its specific receptors. Among these, gonadotropin-releasing hormone receptor type I (GnRHR I), which is a member of the G-protein-coupled receptor family, is expressed on the surface of both healthy and malignant cells. Its presence in cancer cells has positioned this receptor as a primary target for the development of novel anti-cancer agents. Moreover, the extensive regulatory functions of GnRH have underscored decapeptide as a prominent vehicle for targeted drug delivery, which is accomplished through the design of appropriate conjugates. On this basis, a rationally designed series of anthraquinone/mitoxantrone-GnRH conjugates (con1-con8) has been synthesized herein. Their in vitro binding affinities range from 0.06 to 3.42 nM, with six of them (con2-con7) demonstrating higher affinities for GnRH than the established drug leuprolide (0.64 nM). Among the mitoxantrone based GnRH conjugates, con3 and con7 show the highest affinities at 0.07 and 0.06 nM, respectively, while the disulfide bond present in the conjugates is found to be readily reduced by the thioredoxin (Trx) system. These findings are promising for further pharmacological evaluation of the synthesized conjugates with the prospect of performing future clinical studies.

EGF-Enhanced GnRH-II Regulation in Decidual Stromal Cell Motility through Twist and N-Cadherin Signaling.

Crucial roles in embryo implantation and placentation in humans include the invasion of the maternal decidua by extravillous trophoblasts and the motile behavior of decidual endometrial stromal cells. The effects of the epidermal growth factor (EGF) and GnRH-II in the endometrium take part in early pregnancy. In the present study, we demonstrated the coaction of EGF- and GnRH-II-promoted motility of human decidual endometrial stromal cells, indicating the possible roles of EGF and GnRH-II in embryo implantation and early pregnancy. After obtaining informed consent, we obtained human decidual endometrial stromal cells from decidual tissues from normal pregnancies at 6 to 12 weeks of gestation in healthy women undergoing suction dilation and curettage. Cell motility was evaluated with invasion and migration assays. The mechanisms of EGF and GnRH-II were performed using real-time PCR and immunoblot analysis. The results showed that human decidual tissue and stromal cells expressed the EGF and GnRH-I receptors. GnRH-II-mediated cell motility was enhanced by EGF and was suppressed by the knockdown of the endogenous GnRH-I receptor and EGF receptor with siRNA, revealing that GnRH-II promoted the cell motility of human decidual endometrial stromal cells through the GnRH-I receptor and the activation of Twist and N-cadherin signaling. This new concept regarding the coaction of EGF- and GnRH-promoted cell motility suggests that EGF and GnRH-II potentially affect embryo implantation and the decidual programming of human pregnancy.

Linking mitochondrial dynamics and fertility: promoting fertility by phoenixin through modulation of ovarian expression of GnRH receptor and mitochondrial dynamics proteins DRP-1 and Mfn-2.

Obesity is linked to reproductive disorders. Novel neuropeptide phoenixin demonstrated many therapeutic actions. In this study, we aim to evaluate phoenixin's potential effect in obesity-induced infertility through modulating mitochondrial dynamics. Ninety adult female rats were divided to 4 groups: (I), fed with normal pellet diet; (II), given phoenixin; (III), fed with high-fat diet. Rats that developed obesity and infertility were divided to 2 groups: (III-A), received no further treatment; (III-B), given phoenixin. Our results showed that phoenixin treatment in obese infertile rats significantly decreased serum levels of insulin and testosterone and ovarian levels of dynamin-related protein1(Drp1),reactive oxygen species ROS, TNF-α, MDA, and caspase-3. Phoenixin treatment also significantly increased serum estrogen progesterone, LH, and FSH together with ovarian levels of GnRH receptor (GnRHR), mitofusin2(Mfn2), mitochondrial transmembrane potential (ΔΨm), and electron transport chain (ETC) complex-I significantly when compared with obese group. Ovarian histopathological changes were similarly improved by phoenixin. Our data demonstrate phoenixin's role in improving obesity-induced infertility.

Quantitative proteomic analysis of GnRH agonist treated GBM cell line LN229 revealed regulatory proteins inhibiting cancer cell proliferation.

BACKGROUND: Gonadotropin-releasing hormone (GnRH) receptor, a rhodopsin-like G-protein coupled receptor (GPCR) family member involved in GnRH signaling, is reported to be expressed in several tumors including glioblastoma multiforme (GBM), one of the most malignant and aggressive forms of primary brain tumors. However, the molecular targets associated with GnRH receptor are not well studied in GBM or in other cancers. The present study aims at investigating the effect of GnRH agonist (Gosarelin acetate) on cell proliferation and associated signaling pathways in GBM cell line, LN229. METHODS: LN229 cells were treated with different concentrations of GnRH agonist (10-10 M to 10-5 M) and the effect on cell proliferation was analyzed by cell count method. Further, total protein was extracted from control and GnRH agonist treated cells (with maximum reduction in cell proliferation) followed by trypsin digestion, labeling with iTRAQ reagents and LC-MS/MS analysis to identify differentially expressed proteins. Bioinformatic analysis was performed for annotation of proteins for the associated molecular function, altered pathways and network analysis using STRING database. RESULTS: The treatment with different concentrations of GnRH agonist showed a reduction in cell proliferation with a maximum reduction of 48.2% observed at 10-6 M. Quantitative proteomic analysis after GnRH agonist treatment (10-6 M) led to the identification of a total of 29 differentially expressed proteins with 1.3-fold change (23 upregulated, such as, kininogen-1 (KNG1), alpha-2-HS-glycoprotein (AHSG), alpha-fetoprotein (AFP), and 6 downregulated, such as integrator complex subunit 11 (CPSF3L), protein FRG1 (FRG1). Some of them are known [KNG1, AHSG, AFP] while others such as inter-alpha-trypsin inhibitor heavy chain H2 (ITIH2), ITIH4, and LIM domain-containing protein 1 (LIMD1) are novel to GnRH signaling pathway. Protein-protein interaction analysis showed a direct interaction of KNG1, a hub molecule, with GnRH, GnRH receptor, EGFR and other interactors including ITIH2, ITIH4 and AHSG. Overexpression of KNG1 after GnRH agonist treatment was validated using Western blot analysis, while a significant inhibition of EGFR was observed after GnRH agonist treatment. CONCLUSIONS: The study suggests a possible link of GnRH signaling with EGFR signaling pathways likely via KNG1. KNG1 inhibitors may be investigated independently or in combination with GnRH agonist for therapeutic applications.

The roles of GnRH in the human central nervous system.

It is widely known that GnRH plays a role in facilitating reproductive function via the HPG axis, and this was once believed to be its only function. However, over the last several decades important neuromodulatory roles of GnRH in multiple brain functions have been elucidated. Multiple GnRH isoforms and receptors have been detected outside the HPG-axis across different species. In this review, we focus on the human CNS where GnRH I and II isoforms and a functional GnRH I receptor have been isolated. We first describe the traditional understanding of GnRH within the hypothalamus and the pituitary and current clinical use of GnRH analogues. We then review the location and function of GnRH-producing neurons and receptors located outside the HPG axis. We next review the GnRH I and II neuron location and quantity and GnRH I receptor gene expression throughout the human brain, using the Allen Brain Map Atlas. This analysis demonstrates a wide expression of GnRH throughout the brain, including prominent expression in the basal forebrain and cerebellum. Lastly, we examine the potential role of GnRH in aging and inflammation and its therapeutic potential for neurodegenerative disease and spinal cord lesions.