Obesity Alters POMC and Kisspeptin Neuron Cross Talk Leading to Reduced Luteinizing Hormone in Male Mice.

Obesity is associated with hypogonadism in males, characterized by low testosterone and sperm number. Previous studies determined that these stem from dysregulation of hypothalamic circuitry that regulates reproduction, by unknown mechanisms. Herein, we used mice fed chronic high-fat diet, which mimics human obesity, to determine mechanisms of impairment at the level of the hypothalamus, in particular gonadotropin-releasing hormone (GnRH) neurons that regulate luteinizing hormone (LH), which then regulates testosterone. Consistent with obese humans, we demonstrated lower LH, and lower pulse frequency of LH secretion, but unchanged pituitary responsiveness to GnRH. LH pulse frequency is regulated by pulsatile GnRH secretion, which is controlled by kisspeptin. Peripheral and central kisspeptin injections, and DREADD-mediated activation of kisspeptin neurons, demonstrated that kisspeptin neurons were suppressed in obese mice. Thus, we investigated regulators of kisspeptin secretion. We determined that the LH response to NMDA was lower in obese mice, corresponding to fewer glutamate receptors in kisspeptin neurons, which may be critical for kisspeptin synchronization. Given that kisspeptin neurons also interact with anorexigenic POMC neurons, which are affected by obesity, we examined their cross talk, and determined that the LH response to either DREADD-mediated activation of POMC neurons or central injection of αMSH, a product of POMC, is abolished in obese mice. This was accompanied by diminished levels of αMSH receptor, MC4R, in kisspeptin neurons. Together, our studies determined that obesity leads to the downregulation of receptors that regulate kisspeptin neurons, which is associated with lower LH pulse frequency, leading to lower LH and hypogonadism.

Cholinergic Control of GnRH Neuron Physiology and Luteinizing Hormone Secretion in Male Mice: Involvement of ACh/GABA Cotransmission.

Gonadotropin-releasing hormone (GnRH)-synthesizing neurons orchestrate reproduction centrally. Early studies have proposed the contribution of acetylcholine (ACh) to hypothalamic control of reproduction, although the causal mechanisms have not been clarified. Here, we report that in vivo pharmacogenetic activation of the cholinergic system increased the secretion of luteinizing hormone (LH) in orchidectomized mice. 3DISCO immunocytochemistry and electron microscopy revealed the innervation of GnRH neurons by cholinergic axons. Retrograde viral labeling initiated from GnRH-Cre neurons identified the medial septum and the diagonal band of Broca as exclusive sites of origin for cholinergic afferents of GnRH neurons. In acute brain slices, ACh and carbachol evoked a biphasic effect on the firing rate in GnRH neurons, first increasing and then diminishing it. In the presence of tetrodotoxin, carbachol induced an inward current, followed by a decline in the frequency of miniature postsynaptic currents (mPSCs), indicating a direct influence on GnRH cells. RT-PCR and whole-cell patch-clamp studies revealed that GnRH neurons expressed both nicotinic (α4ß2, α3ß4, and α7) and muscarinic (M1-M5) AChRs. The nicotinic AChRs contributed to the nicotine-elicited inward current and the rise in firing rate. Muscarine via M1 and M3 receptors increased, while via M2 and M4 reduced the frequency of both mPSCs and firing. Optogenetic activation of channelrhodopsin-2-tagged cholinergic axons modified GnRH neuronal activity and evoked cotransmission of ACh and GABA from a subpopulation of boutons. These findings confirm that the central cholinergic system regulates GnRH neurons and activates the pituitary-gonadal axis via ACh and ACh/GABA neurotransmissions in male mice.

Hindbrain Adenosine 5-Triphosphate (ATP)-Purinergic Signaling Triggers LH Surge and Ovulation via Activation of AVPV Kisspeptin Neurons in Rats.

Ovulation disorders are a serious problem for humans and livestock. In female rodents, kisspeptin neurons in the anteroventral periventricular nucleus (AVPV) are responsible for generating a luteinizing hormone (LH) surge and consequent ovulation. Here, we report that adenosine 5-triphosphate (ATP), a purinergic receptor ligand, is a possible neurotransmitter that stimulates AVPV kisspeptin neurons to induce an LH surge and consequent ovulation in rodents. Administration of an ATP receptor antagonist (PPADS) into the AVPV blocked the LH surge in ovariectomized (OVX) rats treated with a proestrous level of estrogen (OVX + high E2) and significantly reduced the ovulation rate in proestrous ovary-intact rats. AVPV ATP administration induced a surge-like LH increase in OVX + high E2 rats in the morning. Importantly, AVPV ATP administration could not induce the LH increase in Kiss1 KO rats. Furthermore, ATP significantly increased intracellular Ca2+ levels in immortalized kisspeptin neuronal cell line, and coadministration of PPADS blocked the ATP-induced Ca2+ increase. Histologic analysis revealed that the proestrous level of estrogen significantly increased the number of P2X2 receptor (an ATP receptor)-immunopositive AVPV kisspeptin neurons visualized by tdTomato in Kiss1-tdTomato rats. The proestrous level of estrogen significantly increased varicosity-like vesicular nucleotide transporter (a purinergic marker)-immunopositive fibers projecting to the vicinity of AVPV kisspeptin neurons. Furthermore, we found that some hindbrain vesicular nucleotide transporter-positive neurons projected to the AVPV and expressed estrogen receptor α, and the neurons were activated by the high E2 treatment. These results suggest that hindbrain ATP-purinergic signaling triggers ovulation via activation of AVPV kisspeptin neurons.SIGNIFICANCE STATEMENT Ovulation disorders, which cause infertility and low pregnancy rates, are a serious problem for humans and livestock. The present study provides evidence that adenosine 5-triphosphate, acting as a neurotransmitter in the brain, stimulates kisspeptin neurons in the anteroventral periventricular nucleus, known as the gonadotropin-releasing hormone surge generator, via purinergic receptors to induce the gonadotropin-releasing hormone/luteinizing hormone surge and ovulation in rats. In addition, histologic analyses indicate that adenosine 5-triphosphate is likely to be originated from the purinergic neurons in the A1 and A2 of the hindbrain. These findings may contribute to new therapeutic controls for hypothalamic ovulation disorders in humans and livestock.

Efficacy, tolerability, and safety of teverelix DP in patients with advanced prostate cancer: A multicenter, open-label, phase 2 trial.

BACKGROUND: Teverelix drug product (DP) is a novel injectable gonadotropin-releasing hormone antagonist. METHODS: An adaptive phase 2, open-label, multicenter trial was conducted in patients with advanced prostate cancer to evaluate the efficacy and safety of a combined subcutaneous (SC) and intramuscular (IM) loading dose regimen of teverelix DP of 120 mg SC + 120 mg IM (Group 1; N = 9) or 180 mg SC + 180 mg IM (Group 2; N = 41) administered at a single visit, followed by 6-weekly SC maintenance doses of 120 mg (Group 1) or 180 mg (Group 2), up to Day 168. The primary endpoint was the proportion of patients achieving castration levels with serum testosterone <0.5 ng/mL at Day 28 with a target castration rate of 90%. Injection sites were inspected by the investigator at every visit and reactions (ISRs) were proactively recorded. RESULTS: The target castration rate was reached in Group 2 (97.5%) but not in Group 1 (62.5%). The castration rates were not maintained to Day 42 (Group 2: 82.5%; Group 1: 50.0%). Suppression of testosterone to castrate levels occurred rapidly (median time: 2 days for both groups). Suppression of testosterone, prostate-specific antigen, follicle-stimulating hormone, and luteinizing hormone was sustained throughout the treatment period, being more prominent with the higher dose. The adverse event (AE) profile was similar between groups. The most common AEs were injection-site induration (n = 40: 80.0%), injection-site erythema (n = 35: 70.0%), and hot flush (n = 21: 42.0%). Most ISRs were Grade 1. CONCLUSION: Overall, the teverelix DP doses were generally well-tolerated but did not adequately maintain castration levels.

A practical guide for assessing and managing cardiovascular risk during androgen-deprivation therapy in patients with prostate cancer.

Prostate cancer is the most common malignancy among men worldwide, and androgen-deprivation therapy (ADT) is a mainstay of treatment. There are observational data demonstrating an increased risk of cardiovascular events in patients who receive ADT, particularly those who have an elevated baseline cardiovascular risk. Because, for most patients with prostate cancer, death is predominantly from noncancer-related causes, cardiovascular disease and its risk factors should be optimized during cancer treatment. This review provides an overview of the landscape of ADT treatment and serves as a guide for appropriate cardiovascular screening and risk-mitigation strategies. The authors emphasize the importance of shared communication between the multidisciplinary cancer team and primary care to improve baseline cardiovascular screening and treatment of modifiable risk factors within this higher risk population.

The tick Ixodes scapularis has five different GPCRs specifically activated by ACP (adipokinetic hormone/corazonin-related peptide).

Insects have about 50 neuropeptide genes and about 70 genes, coding for neuropeptide G protein-coupled receptors (GPCRs). An important, but small family of evolutionarily related insect neuropeptides consists of adipokinetic hormone (AKH), corazonin, and AKH/corazonin-related peptide (ACP). Normally, insects have one specific GPCR for each of these neuropeptides. The tick Ixodes scapularis is not an insect, but belongs to the subphylum Chelicerata, which comprises ticks, scorpions, mites, spiders, and horseshoe crabs. Many of the neuropeptides and neuropeptide GPCRs occurring in insects, also occur in chelicerates, illustrating that insects and chelicerates are evolutionarily closely related. The tick I. scapularis is an ectoparasite and health risk for humans, because it infects its human host with dangerous pathogens during a blood meal. Understanding the biology of ticks will help researchers to prevent tick-borne diseases. By annotating the I. scapularis genome sequence, we previously found that ticks contain as many as five genes, coding for presumed ACP receptors. In the current paper, we cloned these receptors and expressed each of them in Chinese Hamster Ovary (CHO) cells. Each expressed receptor was activated by nanomolar concentrations of ACP, demonstrating that all five receptors were functional ACP receptors. Phylogenetic tree analyses showed that the cloned tick ACP receptors were mostly related to insect ACP receptors and, next, to insect AKH receptors, suggesting that ACP receptor genes and AKH receptor genes originated by gene duplications from a common ancestor. Similar duplications have probably occurred for the ligand genes, during a process of ligand/receptor co-evolution. Interestingly, chelicerates, in contrast to all other arthropods, do not have AKH or AKH receptor genes. Therefore, the ancestor of chelicerates might have lost AKH and AKH receptor genes and functionally replaced them by ACP and ACP receptor genes. For the small family of AKH, ACP, and corazonin receptors and their ligands, gene losses and gene gains occur frequently between the various ecdysozoan clades. Tardigrades, for example, which are well known for their survival in extreme environments, have as many as ten corazonin receptor genes and six corazonin peptide genes, while insects only have one of each, or none.

Postnatal feeding with high-fat combined with high-glucose diet induces precocious puberty in Sprague‒Dawley rat pups.

With economic development and overnutrition, including high-fat diets (HFD) and high-glucose diets (HGD), the incidence of obesity in children is increasing, and thus, the incidence of precocious puberty is increasing. Therefore, it is of great importance to construct a suitable animal model of overnutrition-induced precocious puberty for further in-depth study. Here, we fed a HFD, HGD, or HFD combined with a HGD to pups after P-21 weaning, while weaned pups fed a normal diet served as the control group. The results showed that HFD combined with a HGD increased the body weight (BW) of weaned rat pups. In addition, a HFD, HGD, and HFD combined with a HGD lowered the age at which vaginal opening occurred and accelerated the vaginal cell cycle. Furthermore, a HFD combined with a HGD increased the weight of the uterus and ovaries of weaned rat pups. Additionally, a HFD combined with a HGD promoted the development of reproductive organs in weaned female rat pups. Ultimately, a HFD combined with a HGD was found to elevate the serum levels of gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), follicle stimulating hormone (FSH), leptin, adiponectin, and oestradiol (E2) and increase hypothalamic GnRH, Kiss-1, and GPR54 expression levels in weaned female rat pups. The current study found that overnutrition, such as that through a HFD combined with HGD, could induce precocious puberty in weaned female rat pups. In addition, a rat model of overnutrition-induced precocious puberty was established.

Chronic estradiol exposure suppresses luteinizing hormone surge without affecting kisspeptin neurons and estrogen receptor alpha in anteroventral periventricular nucleus†.

Mammalian ovulation is induced by a luteinizing hormone surge, which is triggered by elevated plasma estrogen levels; however, chronic exposure to high levels of estradiol is known to inhibit luteinizing hormone secretion. In the present study, we hypothesized that the inhibition of the luteinizing hormone surge by chronic estradiol exposure is due to the downregulation of the estrogen receptor alpha in kisspeptin neurons at hypothalamic anteroventral periventricular nucleus, which is known as the gonadotropin-releasing hormone/luteinizing hormone surge generator. Animals exposed to estradiol for 2 days showed an luteinizing hormone surge, whereas those exposed for 14 days showed a significant suppression of luteinizing hormone. Chronic estradiol exposure did not affect the number of kisspeptin neurons and the percentage of kisspeptin neurons with estrogen receptor alpha or c-Fos in anteroventral periventricular nucleus, but it did affect the number of kisspeptin neurons in arcuate nucleus. Furthermore, chronic estradiol exposure did not affect gonadotropin-releasing hormone neurons. In the pituitary, 14-day estradiol exposure significantly reduced the expression of Lhb mRNA and LHß-immunoreactive areas. Gonadotropin-releasing hormone-induced luteinizing hormone release was also reduced significantly by 14-day estradiol exposure. We revealed that the suppression of an luteinizing hormone surge by chronic estradiol exposure was induced in association with the significant reduction in kisspeptin neurons in arcuate nucleus, luteinizing hormone expression in the pituitary, and pituitary responsiveness to gonadotropin-releasing hormone, and this was not caused by changes in the estrogen receptor alpha-expressing kisspeptin neurons in anteroventral periventricular nucleus and gonadotropin-releasing hormone neurons, which are responsible for estradiol positive feedback.

Cardiovascular Risk in Prostate Cancer Patients Using Luteinizing Hormone-Releasing Hormone Agonists or a Gonadotropin-Releasing Hormone Antagonist.

PURPOSE: Luteinizing hormone-releasing hormone (LHRH) agonists are believed to have higher cardiovascular risk relative to gonadotropin-releasing hormone (GnRH) antagonists. However, previous studies have not consistently demonstrated this. We used real-world clinical practice data to evaluate differences in major adverse cardiovascular events (MACE) risk between LHRH agonists compared to a GnRH antagonist following androgen deprivation therapy (ADT) initiation. MATERIALS AND METHODS: We performed a retrospective analysis of data in the Decision Resources Group (now Clarivate) Real World Evidence repository, which represents >300 million US patients from 1991 to 2020 across all US regions. Patients with prostate cancer who received at least 1 injection of ADT were included. The risks of MACE and all-cause mortality as independent endpoints were evaluated, Kaplan-Meier curves were constructed, and associations between MACE and all available confounding risk factors were evaluated by Cox regression analysis using Statistical Package for the Social Sciences. RESULTS: A total of 45,059 men with prostate cancer treated with ADT were analyzed. Overall, the risks of MACE and all-cause mortality were slightly lower in the first year after ADT initiation compared to subsequent years. MACE risk was higher for the GnRH antagonist compared to LHRH agonists (HR=1.62; 95% CI 1.21-2.18, P = .001). The risk of all-cause mortality was also higher for the GnRH antagonist vs LHRH agonists (HR=1.87; 95% CI 1.39-2.51, P < .001). CONCLUSIONS: The adjusted incidence of MACE was higher for men treated with the GnRH antagonist compared to the LHRH agonists. The demographic and risk factors with the greatest impact on MACE risk were higher age, baseline metastasis, oncology (vs urology) setting, personal MACE history, antagonist (vs agonist), tobacco history, White (vs Black) race, and lower BMI.

BEYOND: a randomized controlled trial comparing efficacy and safety of individualized follitropin delta dosing in a GnRH agonist versus antagonist protocol during the first ovarian stimulation cycle.

STUDY QUESTION: How does a gonadotrophin-releasing hormone (GnRH) agonist versus a GnRH antagonist protocol affect ovarian response when using an individualized fixed daily dose of follitropin delta for ovarian stimulation? SUMMARY ANSWER: The BEYOND trial data demonstrate thatindividualized fixed-dose follitropin delta is effective when used in a GnRH agonist protocol, compared with a GnRH antagonist protocol, in women with anti-Müllerian hormone (AMH) ≤35 pmol/l and no increased risk of ovarian hyperstimulation syndrome (OHSS). WHAT IS KNOWN ALREADY: The efficacy and safety of an individualized fixed daily dose of follitropin delta (based on body weight and AMH) have been established in randomized controlled trials (RCTs) using a GnRH antagonist protocol. Preliminary study data indicate that individualized follitropin delta is also efficacious in a GnRH agonist protocol (RAINBOW trial, NCT03564509). There are no prospective comparative data using individualized follitropin delta for ovarian stimulation in a GnRH agonist versus a GnRH antagonist protocol. STUDY DESIGN, SIZE, DURATION: This is the first randomized, controlled, open-label, multi-centre trial exploring efficacy and safety of individualized follitropin delta dosing in a GnRH agonist versus a GnRH antagonist protocol in participants undergoing their first ovarian stimulation cycle for IVF/ICSI. A total of 437 participants were randomized centrally and stratified by centre and age. The primary endpoint was the number of oocytes retrieved. Secondary endpoints included ongoing pregnancy rates, adverse drug reactions (including OHSS), live births, and neonatal outcomes. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants (18-40 years; AMH ≤35 pmol/l) were enrolled at specialist reproductive health clinics in Austria, Denmark, Israel, Italy, the Netherlands, Norway, and Switzerland. The mean number of oocytes retrieved was compared between the GnRH agonist and antagonist protocols using a negative binomial regression model with age and AMH at screening as factors. Analyses were based on all randomized subjects, using a multiple imputation method for randomized subjects withdrawing before the start of stimulation. MAIN RESULTS AND THE ROLE OF CHANCE: Of the 437 randomized subjects, 221 were randomized to the GnRH agonist, and 216 were randomized to the GnRH antagonist protocol. The participants had a mean age of 32.3 ± 4.3 years and a mean serum AMH of 16.6 ± 7.8 pmol/l. A total of 202 and 204 participants started ovarian stimulation with follitropin delta in the GnRH agonist and antagonist groups, respectively. The mean number of oocytes retrieved was statistically significantly higher in the agonist group (11.1 ± 5.9) versus the antagonist group (9.6 ± 5.5), with an estimated mean difference of 1.31 oocytes (95% CI: 0.22; 2.40, P = 0.0185). The difference in number of oocytes retrieved was influenced by the patients' age and ovarian reserve, with a greater difference observed in patients aged <35 years and in patients with high ovarian reserve (AMH >15 pmol/l). Both the GnRH agonist and antagonist groups had a similar proportion of cycle cancellations (2.0% [4/202] versus 3.4% [7/204]) and fresh blastocyst transfer cancellations (13.4% [27/202] versus 14.7% [30/204]). The estimated ongoing pregnancy rate per started cycle was numerically higher in the GnRH agonist group (36.9% versus 29.1%; difference: 7.74% [95% CI: -1.49; 16.97, P = 0.1002]). The most commonly reported adverse events (≥1% in either group; headache, OHSS, nausea, pelvic pain, or discomfort and abdominal pain) were similar in both groups. The incidence of early moderate/severe OHSS was low (1.5% for the agonist group versus 2.5% for antagonist groups). Estimated live birth rates per started cycle were 35.8% and 28.7% in the GnRH agonist and antagonist groups, respectively (treatment difference 7.15%; 95% CI: -2.02; 16.31; P = 0.1265). The two treatment groups were comparable with respect to neonatal health data for singletons and twins and for incidence of congenital malformations (2.7% and 3.3% for the GnRH agonist versus antagonist groups, respectively). LIMITATIONS, REASONS FOR CAUTION: All participants had AMH ≤35 pmol/l and were ≤40 years old. Clinicians should remain cautious when using a GnRH agonist protocol in patients with AMH >35 pmol/l (i.e. those with an increased OHSS risk). The incidence of OHSS in the GnRH antagonist group may have been lower if a GnRH agonist trigger had been allowed. Outcomes of transfers with cryopreserved blastocysts were not followed up, therefore the cumulative live birth rates and neonatal outcomes after cryotransfer are unknown. WIDER IMPLICATIONS OF THE FINDINGS: In women with AMH ≤35 pmol/l, an individualized fixed daily dose of follitropin delta resulted in a significantly higher number of oocytes retrieved when used in a GnRH agonist protocol compared with a GnRH antagonist protocol, with no additional safety signals observed and no additional risk of OHSS. Live birth rates following ovarian stimulation with individualized follitropin delta were not statistically different between the GnRH protocols; however, the trial was not powered to assess this endpoint. There were no safety concerns with respect to neonatal health after ovarian stimulation with follitropin delta in either protocol. STUDY FUNDING/COMPETING INTEREST(S): The trial was funded by Ferring Pharmaceuticals. EE, EP, and MS have no competing interests. AP has received research support from Ferring, and Gedeon Richter, and honoraria or consultation fees from Preglem, Novo Nordisk, Ferring, Gedeon Richter, Cryos, Merck A/S. BC has received consulting fees from Ferring and Merck, and his department received fees from Ferring to cover the costs of patient enrolment. MBS has received support to attend meetings and/or travel from Ferring, and was a board member for FertiPROTEKT e.V. until 2023. JS has received honoraria or consultation fees from Ferring and Merck, and support for attending meetings and/or travel from Ferring, Merck, and GoodLife. TS has received support/travel expenses from Ferring for attending a congress meeting, and participated in an advisory board for Merck. YS has received grants/research support from Ferring and support to attend a professional society congress meeting from Merck. RL and PP are employees of Ferring Pharmaceuticals. PP is a BOD member of PharmaBiome and owns stocks of Takeda Pharmaceuticals. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov identifier NCT03809429; EudraCT Number 2017-002783-40. TRIAL REGISTRATION DATE: 7 April 2019. DATE OF FIRST PATIENT'S ENROLMENT: 2 May 2019.

Targeted inhibition of kisspeptin neurons reverses hyperandrogenemia and abnormal hyperactive LH secretion in a preclinical mouse model of polycystic ovary syndrome.

STUDY QUESTION: Do hyperactive kisspeptin neurons contribute to abnormally high LH secretion and downstream hyperandrogenemia in polycystic ovary syndrome (PCOS)-like conditions and can inhibition of kisspeptin neurons rescue such endocrine impairments? SUMMARY ANSWER: Targeted inhibition of endogenous kisspeptin neuron activity in a mouse model of PCOS reduced the abnormally hyperactive LH pulse secretion and hyperandrogenemia to healthy control levels. WHAT IS KNOWN ALREADY: PCOS is a reproductive disorder characterized by hyperandrogenemia, anovulation, and/or polycystic ovaries, along with a hallmark feature of abnormal LH hyper-pulsatility, but the mechanisms underlying the endocrine impairments remain unclear. A chronic letrozole (LET; aromatase inhibitor) mouse model recapitulates PCOS phenotypes, including polycystic ovaries, anovulation, high testosterone, and hyperactive LH pulses. LET PCOS-like females also have increased hypothalamic kisspeptin neuronal activation which may drive their hyperactive LH secretion and hyperandrogenemia, but this has not been tested. STUDY DESIGN, SIZE, DURATION: Transgenic KissCRE+/hM4Di female mice or littermates Cre- controls were treated with placebo, or chronic LET (50 µg/day) to induce a PCOS-like phenotype, followed by acute (once) or chronic (2 weeks) clozapine-N-oxide (CNO) exposure to chemogenetically inhibit kisspeptin cells (n = 6 to 10 mice/group). PARTICIPANTS/MATERIALS, SETTING, METHODS: Key endocrine measures, including in vivo LH pulse secretion patterns and circulating testosterone levels, were assessed before and after selective kisspeptin neuron inhibition and compared between PCOS groups and healthy controls. Alterations in body weights were measured and pituitary and ovarian gene expression was determined by qRT-PCR. MAIN RESULTS AND THE ROLE OF CHANCE: Acute targeted inhibition of kisspeptin neurons in PCOS mice successfully lowered the abnormally hyperactive LH pulse secretion (P < 0.05). Likewise, chronic selective suppression of kisspeptin neuron activity reversed the previously high LH and testosterone levels (P < 0.05) down to healthy control levels and rescued reproductive gene expression (P < 0. 05). LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: Ovarian morphology was not assessed in this study. Additionally, mouse models can offer mechanistic insights into neuroendocrine processes in PCOS-like conditions but may not perfectly mirror PCOS in women. WIDER IMPLICATIONS OF THE FINDINGS: These data support the hypothesis that overactive kisspeptin neurons can drive neuroendocrine PCOS-like impairments, and this may occur in PCOS women. Our findings complement recent clinical investigations using NKB receptor antagonists to lower LH in PCOS women and suggest that pharmacological dose-dependent modulation of kisspeptin neuron activity may be a valuable future therapeutic target to clinically treat hyperandrogenism and lower elevated LH in PCOS women. STUDY FUNDING/COMPETING INTEREST(S): This research was supported by NIH grants R01 HD111650, R01 HD090161, R01 HD100580, P50 HD012303, R01 AG078185, and NIH R24 HD102061, and a pilot project award from the British Society for Neuroendocrinology. There are no competing interests.

A modified flexible GnRH antagonist protocol using antagonist early cessation and a gonadotropin step-down approach improves live birth rates in fresh cycles: a randomized controlled trial.

STUDY QUESTION: Can pregnancy outcomes following fresh elective single embryo transfer (eSET) in gonadotropin-releasing hormone (GnRH) antagonist protocols increase using a gonadotropin (Gn) step-down approach with cessation of GnRH antagonist on the day of hCG administration (hCG day) in patients with normal ovarian response? SUMMARY ANSWER: The modified GnRH antagonist protocol using the Gn step-down approach and cessation of GnRH antagonist on the hCG day is effective in improving live birth rates (LBRs) per fresh eSET cycle. WHAT IS KNOWN ALREADY: Currently, there is no consensus on optimal GnRH antagonist regimens. Studies have shown that fresh GnRH antagonist cycles result in poorer pregnancy outcomes than the long GnRH agonist (GnRHa) protocol. Endometrial receptivity is a key factor that contributes to this phenomenon. STUDY DESIGN, SIZE, DURATION: An open label randomized controlled trial (RCT) was performed between November 2021 and August 2022. There were 546 patients allocated to either the modified GnRH antagonist or the conventional antagonist protocol at a 1:1 ratio. PARTICIPANTS/MATERIALS, SETTING, METHODS: Both IVF and ICSI cycles were included, and the sperm samples used were either fresh or frozen from the partner, or from frozen donor ejaculates. The primary outcome was the LBRs per fresh SET cycle. Secondary outcomes included rates of implantation, clinical and ongoing pregnancy, miscarriage, and ovarian hyperstimulation syndrome (OHSS), as well as clinical outcomes of ovarian stimulation. MAIN RESULTS AND THE ROLE OF CHANCE: Baseline demographic features were not significantly different between the two ovarian stimulation groups. However, in the intention-to-treat (ITT) population, the LBRs in the modified antagonist group were significantly higher than in the conventional group (38.1% [104/273] vs. 27.5% [75/273], relative risk 1.39 [95% CI, 1.09-1.77], P = 0.008). Using a per-protocol (PP) analysis which included all the patients who received an embryo transfer, the LBRs in the modified antagonist group were also significantly higher than in the conventional group (48.6% [103/212] vs. 36.8% [74/201], relative risk 1.32 [95% CI, 1.05-1.66], P = 0.016). The modified antagonist group achieved significantly higher implantation rates, and clinical and ongoing pregnancy rates than the conventional group in both the ITT and PP analyses (P < 0.05). The two groups did not show significant differences between the number of oocytes retrieved or mature oocytes, two-pronuclear zygote (2PN) rates, the number of embryos obtained, blastocyst progression and good-quality embryo rates, early miscarriage rates, or OHSS incidence rates (P > 0.05). LIMITATIONS, REASONS FOR CAUTION: A limitation of our study was that the subjects were not blinded to the treatment allocation in the RCT trial. Only women under 40 years of age who had a good prognosis were included in the analysis. Therefore, use of the modified antagonist protocol in older patients with a low ovarian reserve remains to be investigated. In addition, the sample size for Day 5 elective SET was small, so larger trials will be required to strengthen these findings. WIDER IMPLICATIONS OF THE FINDINGS: The modified GnRH antagonist protocol using the Gn step-down approach and cessation of GnRH antagonist on hCG day improved the LBRs per fresh eSET cycle in normal responders. STUDY FUNDING/COMPETING INTEREST(S): This project was funded by grant 2022YFC2702503 from the National Key Research & Development Program of China and grant 2021140 from the Beijing Health Promotion Association. The authors declare no conflicts of interest. TRIAL REGISTRATION NUMBER: The RCT was registered in the Chinese Clinical Trial Registry; Study Number: ChiCTR2100053453. TRIAL REGISTRATION DATE: 21 November 2021. DATE OF FIRST PATIENT'S ENROLLMENT: 23 November 2021.

Linzagolix therapy versus a placebo in patients with endometriosis-associated pain: a prospective, randomized, double-blind, Phase 3 study (EDELWEISS 3).

STUDY QUESTION: Does linzagolix administered orally once daily for up to 3 months at a dose of 75 mg alone or 200 mg in combination with add-back therapy (ABT) (1.0 mg estradiol; 0.5 mg norethindrone acetate, also known as norethisterone acetate [NETA]) demonstrate better efficacy than placebo in the management of endometriosis-related dysmenorrhea and non-menstrual pelvic pain? SUMMARY ANSWER: Combining 200 mg linzagolix with ABT was found to significantly reduce dysmenorrhea and non-menstrual pelvic pain at 3 months of therapy, while a daily dose of 75 mg linzagolix yielded a significant decrease only in dysmenorrhea at 3 months. WHAT IS KNOWN ALREADY?: A previously published Phase 2, dose-finding study reported that at a dose of 200 mg daily, linzagolix promotes full suppression of estradiol secretion to serum levels below 20 pg/ml and noted that the addition of ABT may be needed to manage hypoestrogenic side effects. At lower doses (75 mg and 100 mg/day), linzagolix maintains estradiol values within the target range of 20-60 pg/ml, which could be ideal to alleviate symptoms linked to endometriosis. STUDY DESIGN, SIZE, DURATION: EDELWEISS 3 was a multicenter, prospective, randomized, placebo-controlled, double-blind, double-dummy Phase 3 study to evaluate the safety and efficacy of linzagolix for the treatment of moderate-to-severe endometriosis-associated pain. Treatment was administered orally once daily for up to 6 months. PARTICIPANTS/MATERIALS, SETTING, METHODS: In the EDELWEISS 3 trial, 486 subjects with moderate-to-severe endometriosis-associated pain were randomized at a 1:1:1 ratio to one of the three study groups: placebo, 75 mg linzagolix alone or 200 mg linzagolix in association with ABT. Pain was measured daily on a verbal rating scale and recorded in an electronic diary. MAIN RESULTS AND THE ROLE OF CHANCE: At 3 months, the daily 200 mg linzagolix dose with ABT met the primary efficacy objective, showing clinically meaningful and statistically significant reductions in dysmenorrhea and non-menstrual pelvic pain, with stable or decreased use of analgesics. The proportion of responders for dysmenorrhea in the 200 mg linzagolix with ABT group was 72.9% compared with 23.5% in the placebo group (P < 0.001), while the rates of responders for non-menstrual pelvic pain were 47.3% and 30.9% (P = 0.007), respectively. The 75 mg linzagolix daily dose demonstrated a clinically meaningful and statistically significant reduction in dysmenorrhea versus placebo at 3 months. The proportion of responders for dysmenorrhea in the 75 mg linzagolix group was 44.0% compared with 23.5% in the placebo group (P < 0.001). Although the 75 mg dose showed a trend toward reduction in non-menstrual pelvic pain at 3 months relative to the placebo, it was not statistically significant (P = 0.279). Significant improvements in dyschezia and overall pelvic pain were observed in both linzagolix groups when compared to placebo. Small improvements in dyspareunia scores were observed in both linzagolix groups but they were not significant. In both groups, hypoestrogenic effects were mild, with low rates of hot flushes and bone density loss of <1%. A daily dose of 200 mg linzagolix with ABT or 75 mg linzagolix alone was found to significantly reduce dysmenorrhea and non-menstrual pelvic pain also at 6 months of therapy. LIMITATIONS, REASONS FOR CAUTION: Efficacy was compared between linzagolix groups and placebo; however, it would be useful to have results from comparative studies with estro-progestogens or progestogens. It will be important to ascertain whether gonadotropin-releasing hormone antagonists have significant benefits over traditional first-line medications. WIDER IMPLICATIONS OF THE FINDINGS: Linzagolix administered orally once daily at a dose of 200 mg in combination with add-back therapy (ABT) demonstrated better efficacy and safety than placebo in the management of moderate-to-severe endometriosis-associated pain. The quality of life was improved and the risks of bone loss and vasomotor symptoms were minimized due to the ABT. The 75 mg dose alone could be suitable for chronic treatment of endometriosis-associated pain without the need for concomitant hormonal ABT, but further research is needed to confirm this. If confirmed, it would offer a viable option for women who do not want to wish to have ABT or for whom it is contraindicated. STUDY FUNDING/COMPETING INTEREST(S): Funding for the EDELWEISS 3 study was provided by ObsEva (Geneva, Switzerland). Analysis of data and manuscript writing were partially supported by ObsEva (Geneva, Switzerland), Theramex (London, UK) and Kissei (Japan) and grant 5/4/150/5 was awarded to M.-M.D. by FNRS. J.D. was a member of the scientific advisory board of ObsEva until August 2022, a member of the scientific advisory board of PregLem, and received personal fees from Gedeon Richter, ObsEva and Theramex. J.D. received consulting fees, speakers' fees, and travel support from Gedeon Richter, Obseva and Theramex, which was paid to their institution. C.B. has received fees from Theramex, Gedeon Richter, and Myovant, and travel support from Gedeon Richter-all funds went to the University of Oxford. He was a member of the data monitoring board supervising the current study, and served at an advisory board for endometriosis studies of Myovant. H.T. has received grants from Abbvie and was past president of ASRM. F.C.H. has received fees from Gedeon Richter and Theramex. O.D. received fees for lectures from Gedeon Richter and ObsEva and research grants for clinical studies from Preglem and ObsEva independent from the current study. A.H. has received grants from NIHR, UKRI, CSO, Wellbeing of Women, and Roche Diagnostics; he has received fees from Theramex. A.H.'s institution has received honoraria for consultancy from Roche Diagnostics, Gesynta, and Joii. M.P. has nothing to declare. F.P. has received fees from Theramex. S.P.R. has been a member of the scientific advisory board of Gedeon Richter and received fees from Gedeon Richter. A.P. and M.B. are employees of Theramex. E.B. was an employee of ObsEva, sponsor chair of the data monitoring board supervising the current study, and has been working as a consultant for Theramex since December 2022; she owns stock options in ObsEva. M.-M.D. has received fees and travel support from Gedeon Richter and Theramex. TRIAL REGISTRATION NUMBER: NCT03992846. TRIAL REGISTRATION DATE: 20 June 2019. DATE OF FIRST PATIENT'S ENROLLMENT: 13 June 2019.

Risk factors for poor oocyte yield and oocyte immaturity after GnRH agonist triggering.

STUDY QUESTION: What are the potential risk factors for poor oocyte recuperation rate (ORR) and oocyte immaturity after GnRH agonist (GnRHa) ovulation triggering? SUMMARY ANSWER: Lower ovarian reserve and LH levels after GnRHa triggering are risk factors of poor ORR. Higher BMI and anti-Müllerian hormone (AMH) levels are risk factors of poor oocyte maturation rate (OMR). WHAT IS KNOWN ALREADY: The use of GnRHa to trigger ovulation is increasing. However, some patients may have a suboptimal response after GnRHa triggering. This suboptimal response can refer to any negative endpoint, such as suboptimal oocyte recovery, oocyte immaturity, or empty follicle syndrome. For some authors, a suboptimal response to GnRHa triggering refers to a suboptimal LH and/or progesterone level following triggering. Several studies have investigated a combination of demographic, clinical, and endocrine characteristics at different stages of the treatment process that may affect the efficacy of the GnRHa trigger and thus be involved in a poor endocrine response or efficiency but no consensus exists. STUDY DESIGN, SIZE, DURATION: Bicentric retrospective cohort study between 2015 and 2021 (N = 1747). PARTICIPANTS/MATERIALS, SETTING, METHODS: All patients aged 18-43 years who underwent controlled ovarian hyperstimulation and ovulation triggering by GnRHa alone (triptorelin 0.2 mg) for ICSI or oocyte cryopreservation were included. The ORR was defined as the ratio of the total number of retrieved oocytes to the number of follicles >12 mm on the day of triggering. The OMR was defined as the ratio of the number of mature oocytes to the number of retrieved oocytes. A logistic regression model with a backward selection method was used for the analysis of risk factors. Odds ratios (OR) are displayed with their two-sided 95% confidence interval. MAIN RESULTS AND THE ROLE OF CHANCE: In the multivariate analysis, initial antral follicular count and LH level 12-h post-triggering were negatively associated with poor ORR (i.e. below the 10th percentile) (OR: 0.61 [95% CI: 0.42-0.88]; P = 0.008 and OR: 0.86 [95% CI: 0.76-0.97]; P = 0.02, respectively). A nonlinear relationship was found between LH level 12-h post-triggering and poor ORR, but no LH threshold was found. A total of 25.3% of patients suffered from oocyte immaturity (i.e. OMR < 75%). In the multivariate analysis, BMI and AMH levels were negatively associated with an OMR < 75% (OR: 4.34 [95% CI: 1.96-9.6]; P < 0.001 and OR: 1.22 [95% CI: 1.03-1.12]; P = 0.015, respectively). Antigonadotrophic pretreatment decreased the risk of OMR < 75% compared to no pretreatment (OR: 0.72 [95% CI: 0.57-0.91]; P = 0.02). LIMITATIONS, REASONS FOR CAUTION: Our study is limited by its retrospective design and by the exclusion of patients who had hCG retriggers. However, this occurred in only six cycles. We were also not able to collect information on the duration of pretreatment and the duration of wash out period. WIDER IMPLICATIONS OF THE FINDINGS: In clinical practice, to avoid poor ORR, GnRHa trigger alone should not be considered in patients with higher BMI and/or low ovarian reserve, balanced by the risk of ovarian hyperstimulation syndrome. In the case of a low 12-h post-triggering LH level, practicians must be aware of the risk of poor ORR, and hCG retriggering could be considered. STUDY FUNDING/COMPETING INTEREST(S): None. TRIAL REGISTRATION NUMBER: N/A.

The functional study of a novel MKRN3 missense mutation associated with familial central precocious puberty.

Central precocious puberty (CPP) refers to a syndrome of early puberty initiation with a characteristic increase in the release of gonadotropin-releasing hormone (GnRH); therefore, it is also called GnRH-related precocious puberty. About a quarter of idiopathic central precocious puberty (ICPP) may be familial. Studies suggest that mutations of makorin ring finger protein 3 (MKRN3) can cause familial central precocious puberty (FCPP). In this report, we describe a Chinese female patient carrying a novel MKRN3 variant (c.980G>A/p.Arg327His) and presenting the CPP phenotype. This novel variant attenuated its own ubiquitination, degradation, and inhibition on the transcriptional and translational activity of GNRH1, which was verified through functional tests. We can consider this variant as a loss-of-function mutation, which subsides the inhibition of GnRH1-related signaling and gives rise to GnRH-related precocious puberty.

Neural thyroid hormone metabolism integrates seasonal changes in environmental temperature with the neuroendocrine reproductive axis.

We asked if environmental temperature alters thyroid hormone metabolism within the hypothalamus, thereby providing a neuroendocrine mechanism by which temperature could be integrated with photoperiod to regulate seasonal rhythms. We used immunohistochemistry to assess the effects of low-temperature winter dormancy at 4 °C or 12 °C on thyroid-stimulating hormone (TSH) within the infundibulum of the pituitary as well as deiodinase 2 (Dio2) and 3 (Dio3) within the hypothalamus of red-sided garter snakes (Thamnophis sirtalis). Both the duration and, in males, magnitude of low-temperature dormancy altered deiodinase immunoreactivity within the hypothalamus, increasing the area of Dio2-immunoreactivity in males and females and decreasing the number of Dio3-immunoreactive cells in males after 8-16 weeks. Reciprocal changes in Dio2/3 favor the accumulation of triiodothyronine within the hypothalamus. Whether TSH mediates these effects requires further study, as significant changes in TSH-immunoreactive cell number were not observed. Temporal changes in deiodinase immunoreactivity coincided with an increase in the proportion of males exhibiting courtship behavior as well as changes in the temporal pattern of courtship behavior after emergence. Our findings mirror those of previous studies, in which males require low-temperature exposure for at least 8 weeks before significant changes in gonadotropin-releasing hormone immunoreactivity and sex steroid hormones are observed. Collectively, these data provide evidence that the neuroendocrine pathway regulating the reproductive axis via thyroid hormone metabolism is capable of transducing temperature information. Because all vertebrates can potentially use temperature as a supplementary cue, these results are broadly applicable to understanding how environment-organism interactions mediate seasonally adaptive responses.

Investigation of luteal HCG supplementation in GnRH-agonist-triggered fresh embryo transfer cycles: a randomized controlled trial.

RESEARCH QUESTION: Does splitting the human chorionic gonadotrophin (HCG) support in IVF cycles triggered by a gonadotrophin-releasing hormone agonist result in a better progesterone profile? DESIGN: Randomized controlled three-arm study, performed at the Fertility Clinic, Odense University Hospital, Denmark. Patients with 12-25 follicles ≥12 mm were randomized into three groups: Group 1 - ovulation triggered with 6500 IU HCG; Group 2 - ovulation triggered with 0.5 mg GnRH agonist, followed by 1500 IU HCG on the day of oocyte retrieval (OCR); and Group 3 - ovulation triggered with 0.5 mg GnRH agonist, followed by 1000 IU HCG on the day of OCR and 500 IU HCG on OCR + 5. All groups received 180 mg vaginal progesterone. Progesterone concentrations were analysed in eight blood samples from each patient. RESULTS: Sixty-nine patients completed the study. Baseline and laboratory data were comparable. Progesterone concentration peaked on OCR + 4 in Groups 1 and 2, and peaked on OCR + 6 in Group 3. On OCR + 6, the progesterone concentration in Group 2 was significantly lower compared with Groups 1 and 3 (P = 0.003 and P < 0.001, respectively). On OCR + 8, the progesterone concentration in Group 3 was significantly higher compared with the other groups (both P<0.001). Progesterone concentrations were significantly higher in Group 3 from OCR + 6 until OCR + 14 compared with the other groups (all P ≤ 0.003). Four patients developed ovarian hyperstimulation syndrome in Group 3. CONCLUSION: Sequential HCG support after a GnRH agonist trigger provides a better progesterone concentration in the luteal phase.

Association between the systemic immune-inflammation index and GnRH antagonist protocol IVF outcomes: a cohort study.

RESEARCH QUESTION: What is the relationship between the systemic immune-inflammation index (SII) and IVF outcomes in women undergoing a gonadotrophin-releasing hormone (GnRH) antagonist protocol? DESIGN: This retrospective cohort study analysed clinical data and blood samples collected before oocyte retrieval from participants undergoing IVF with the GnRH antagonist protocol. Logistic regression and generalized additive models were used to examine the association between SII quartiles and continuous SII values and IVF outcomes. RESULTS: Higher SII values correlated negatively with biochemical pregnancy, clinical pregnancy, live birth and implantation rates, and positively with early pregnancy loss, independent of age, body mass index, anti-Müllerian hormone and stimulation parameters. The most significant adverse outcomes were observed in the highest SII quartile. A non-linear relationship was identified between log-transformed SII and IVF outcomes, with an inflection point at an SII of approximately 6.72, indicating a threshold effect. CONCLUSIONS: Elevated SII is associated with poorer IVF outcomes in women after the GnRH antagonist protocol, suggesting its potential as a predictive marker in IVF treatments. Further research is needed to confirm these findings and explore the underlying mechanisms.

Relugolix combination therapy in Black/African American women with symptomatic uterine fibroids: LIBERTY Long-Term Extension study.

BACKGROUND: In the LIBERTY Long-Term Extension study, once-daily relugolix combination therapy (40 mg relugolix, estradiol 1 mg, norethindrone acetate 0.5 mg) substantially improved uterine fibroid-associated heavy menstrual bleeding throughout the 52-week treatment period in the overall study population. OBJECTIVE: Black or African American women typically experience a greater extent of disease and symptom burden of uterine fibroids vs other racial groups and have traditionally been underrepresented in clinical trials. This secondary analysis aimed to assess the efficacy and safety of relugolix combination therapy in the subgroup population of Black or African American women with uterine fibroids in the LIBERTY Long-Term Extension study. STUDY DESIGN: Black or African American premenopausal women (aged 18-50 years) with uterine fibroids and heavy menstrual bleeding who completed the 24-week randomized, placebo-controlled, double-blind LIBERTY 1 (identifier: NCT03049735) or LIBERTY 2 (identifier: NCT03103087) trials were eligible to enroll in the 28-week LIBERTY Long-Term Extension study (identifier: NCT03412890), in which all women received once-daily, open-label relugolix combination therapy. The primary endpoint of this subanalysis was the proportion of Black or African American treatment responders: women who achieved a menstrual blood loss volume of <80 mL and at least a 50% reduction in menstrual blood loss volume from the pivotal study baseline to the last 35 days of treatment by pivotal study randomized treatment group. The secondary outcomes included rates of amenorrhea and changes in symptom burden and quality of life. RESULTS: Overall, 241 of 477 women (50.5%) enrolled in the LIBERTY Long-Term Extension study self-identified as Black or African American. In Black or African American women receiving continuous relugolix combination therapy for up to 52 weeks, 58 of 70 women (82.9%; 95% confidence interval, 72.0%-90.8%) met the treatment responder criteria for reduction in heavy menstrual bleeding (primary endpoint). A substantial reduction in menstrual blood loss volume from the pivotal study baseline to week 52 was demonstrated (least squares mean percentage change: 85.0%); 64.3% of women achieved amenorrhea; 59.1% of women with anemia at the pivotal study baseline achieved a substantial improvement (>2 g/dL) in hemoglobin levels; and decreased symptom severity and distress because of uterine fibroid-associated symptoms and improvements in health-related quality of life through 52 weeks were demonstrated. The most frequently reported adverse events during the cumulative 52-week treatment period were hot flush (12.9%), headache (5.7%), and hypertension (5.7%). Bone mineral density was preserved through 52 weeks. CONCLUSION: Once-daily relugolix combination therapy improved uterine fibroid-associated heavy menstrual bleeding in most Black or African American women who participated in the LIBERTY Long-Term Extension study. The safety and efficacy profile of relugolix combination therapy in Black or African American women was consistent with previously published results from the overall study population through 52 weeks. Findings from this subanalysis will assist shared decision-making by helping providers and Black or African American women understand the efficacy and safety of relugolix combination therapy as a pharmacologic option for the management of uterine fibroid-associated symptoms.

Considerations on implementation of the newest treatment for symptomatic uterine fibroids: Oral GnRH antagonists.

Novel gonadotrophin releasing hormone (GnRH) antagonist treatments have recently been developed in combination with hormonal add-back therapy, as an oral treatment option for women suffering from uterine fibroids. Registration trials assessing the GnRH antagonist combination preparations with relugolix, elagolix and linzagolix have assessed treatment efficacy for fibroid-related heavy menstrual blood loss in comparison to placebo. Marketing authorization has been granted by several agencies including those in Europe, the United Kingdom and the United States. While the registration trials report a robust effect on the reduction of heavy menstrual blood loss and improvement in quality of life scores, reticence is advised before widespread prescription. In this review, we demonstrate limitations in the trial data, namely a lack of generalizability due to the restricted study population, the lack of transparency in the distribution of disease-level characteristics limiting the predictability of treatment success in the real-world diverse population, and the absence of any comparison to current alternative treatment methods. Importantly, no clinically meaningful volume reductions were found with GnRH antagonist combination preparations, and long-term safety data, particularly concerning modest but stable bone mineral density decline, need further addressing. Symptoms related to uterine fibroids adversely affect many women's quality of life and effective medical treatments are lacking. However, despite the urgent need for conservative treatments, it is vitally important that novel drugs, like combination oral GnRH antagonists, undergo sufficiently rigorous evaluation of safety, effectiveness and cost-effectiveness in a representative population and are compared with alternative treatment methods before introduction into mainstream clinical practice.