Gonadotropin Releasing Research Articles

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.

The Role of RFRP Neurons in the Allostatic Control of Reproductive Function.

Reproductive function is critical for species survival; however, it is energetically costly and physically demanding. Reproductive suppression is therefore a physiologically appropriate adaptation to certain ecological, environmental, and/or temporal conditions. This 'allostatic' suppression of fertility enables individuals to accommodate unfavorable reproductive circumstances and safeguard survival. The mechanisms underpinning this reproductive suppression are complex, yet culminate with the reduced secretion of gonadotropin-releasing hormone (GnRH) from the hypothalamus, which in turn suppresses gonadotropin release from the pituitary, thereby impairing gonadal function. The focus of this review will be on the role of RFamide-related peptide (RFRP) neurons in different examples of allostatic reproductive suppression. RFRP neurons release the RFRP-3 peptide, which negatively regulates GnRH neurons and thus appears to act as a 'brake' on the neuroendocrine reproductive axis. In a multitude of predictable (e.g., pre-puberty, reproductive senescence, and seasonal or lactational reproductive quiescence) and unpredictable (e.g., metabolic, immune and/or psychosocial stress) situations in which GnRH secretion is suppressed, the RFRP neurons have been suggested to act as modulators. This review examines evidence for and against these roles.

Adjuvant letrozole administration in gonadotropin releasing hormone antagonist cycles do not affect ploidy status of embryos

ObjectiveTo evaluate the effects of adjuvant letrozole administration on euploid embryo rates in gonadotropin releasing hormone (GnRH) antagonist cycles. MethodsThis retrospective study was conducted by analyzing data of patients that underwent GnRH antagonist cycles with intra-cytoplasmic sperm injection (ICSI) and pre-implantation genetic testing for aneuploidy between 2013 and 2021. Study included a total of 713 patients which 84 of them were received adjuvant letrozole and 629 patients underwent ovulation induction without any adjuvant therapy. ResultsIn patients with letrozole administration, total dose of consumed gonadotropins were significantly lower (2166.80 ± 738.82 IU vs. 2541.96 ± 755.76 IU; p < 0.001, respectively), and duration of stimulation was slightly longer (9.80 ± 1.23 days vs. 9.53 ± 1.38 days; p = 0.037) in comparison to patients without letrozole administration. Overall euploidy rates were found similar among letrozole group and control group (28.02 % ± 31.08 % vs. 23.02 % ± 30.87 %; p = 0.109). Similar rate of euploidy remained even after stratification of patients in accordance with female age. There was no significant difference in terms of live birth rates between letrozole administered group and control group (66.7 % vs 62.2 %, respectively). ConclusionCo-treatment with 5 mg/day letrozole for 5 days does not appear to affect euploidy rates of obtained embryos in GnRH antagonist cycles with ICSI.

Molecular characterization of gonadotropin-releasing hormone receptor and its expression profiling in response to HCG stimulation in striped murrel, Channa striata (Bloch, 1793)

The gonadotropin releasing hormone receptors (GnRHR) play an important role in the activation of GnRH and elicit the release of gonadotropins that plays an important role in maturation and spawning. In the present work, molecular characterization of the GnRHR gene of snakehead murrel, Channa striata was carried out. The full-length cDNA of GnRH receptors of the 1581 bp sequence, which encodes 440 amino acids was identified by RACE-PCR. Signal peptide analysis confirmed that GnRHR is a non-secretory protein, and hydropathy profiles indicated its hydrophobic nature. The deduced amino acid sequences of the GnRHR showed the expected conserved domains, which include seven membrane-spanning domains, two potential N-linked glycosylation sites (631 Asp, 561 Asp), and 32 sites phosphorylation sites of serine and threonine residues. A homology search of GnRHR cDNA sequence revealed 88 % identity with Channa argus, followed by 85 % and 83 % sequence identities with Lates calcarifer, and Anabas testudineus at the protein level. Phylogenetic analysis depicted a close association with Channa argus and other fish species. Our findings showed differential GnRHR expression during different reproductive stages, with higher expression after HCG administration. Expression profiling revealed that GnRHR is highly expressed in the brain and testis at 16 h post-HCG injection, while it was neutrally regulated in female ovarian tissues. This study provides full-length coding sequence information of the GnRHR gene and will help to understand the reproductive biology of murrel using expression studies and devise strategies for induced breeding.

55 The Effects of Dietary Net Energy Levels on Grow-Finish Performance and Carcass Characteristics of Market Gilts Managed with Improvest

Abstract Improvest is a gonadotropin releasing factor (GnRF) analogue-diphtheria toxoid conjugate injection approved for temporary suppression of ovarian function and estrus in market gilts (Zoetis Canada Inc.). Study objectives were to determine the effects of three different net energy levels (LOW – 2.216 Mcal/kg, MID – 2.341 Mcal/kg, or HIGH – 2.466 Mcal/kg) during the grow-finish period on live performance and carcass characteristics of market gilts managed with Improvest (IMP) compared with market gilts not managed with Improvest (CON). The study consisted of 1,008 market gilts (average starting weight of 30.8 kg) in 48 pens (21 pigs/pen) with experimental treatments arranged as a 2 × 3 factorial design with main effects of Improvest (IMP or CON) and net energy level (LOW, MID, or HIGH). An equal number of pigs were marketed from each of the six treatment groups on day-83 (21.9% of the population), day-90 (21.9% of the population), day-97 (21.9% of the population), and day-104 (34.3% of the population) of the experiment. The weighted average for time post-second Improvest injection to marketing was 39.8 days. Data were analyzed with PROC MIXED of SAS, with pen serving as the experimental unit, fixed effects of Improvest (IMP or CON), net energy level (LOW, MID, or HIGH) and their interaction, and a random effect of pen location. There were no significant interactions (P ≥ 0.20) for average daily feed intake (ADFI), average daily gain (ADG), Feed:Gain (F:G), hot carcass weight (HCW), dressing percentage, backfat thickness, or predicted lean yield. However, IMP gilts consumed more feed (6.8% greater ADFI; P &amp;lt; 0.01), grew faster (5.0% greater ADG; P &amp;lt; 0.01), were less efficient (1.5% greater F:G; P &amp;lt; 0.01), were heavier (3.5 kg HCW; P &amp;lt; 0.01), and were fatter (1.9 mm greater backfat thickness and 0.9% less predicted lean yield; P &amp;lt; 0.01) than CON gilts. No difference (P = 0.21) in carcass dressing percentage between IMP and CON gilts was detected (Table 1). There were significant effects (P &amp;lt; 0.05) of net energy level for ADFI, ADG, F:G, HCW, and dressing percentage. Pigs fed LOW diets had the greatest ADFI, slightly less ADG, the least efficient F:G ratio, the lightest HCW, and reduced dressing percentage compared with HIGH (P &amp;lt; 0.01). There were no differences (P &amp;gt; 0.05) for backfat thickness or predicted lean yield among dietary energy level treatments. Overall, these data indicate that typical Improvest response levels were sustained at each of the net energy levels evaluated in this study (response levels for HCW of 2.6 kg for LOW, 3.4 kg for MID, and 4.5 kg for HIGH); however, consideration should still be provided to the known production impacts of low net energy diets when market gilts are managed with Improvest.

Central precocious puberty secondary to peripheral precocious puberty due to a pineal germ cell tumor: a case and review of literature

BackgroundThe pineal lesion affecting melatonin is a rare cause of central precocious puberty by decreasing the inhibition of hypothalamic–pituitary–gonadal axis. Germ cell tumor secreting human chorionic gonadotropin is a rare cause of peripheral puberty.Case presentationA 5.8-year-old male presented facial hair and phallic growth, deepened voice, and accelerated growth velocity for 6 months. The elevated human chorionic gonadotropin level with undetectable gonadotropin levels indicated peripheral precocious puberty. Brain imaging revealed a pineal mass and further pathology indicated the diagnosis of teratoma. During chemoradiotherapy with operation, the elevated human chorionic gonadotropin level reduced to normal range, while the levels of gonadotropins and testosterone increased. Subsequently, progressing precocious puberty was arrested with gonadotrophin-releasing hormone analog therapy. Previous cases of transition from peripheral precocious puberty to central precocious puberty were reviewed. The transitions were caused by the suddenly reduced feedback inhibition of sex steroid hormones on gonadotropin releasing hormone and gonadotropins.ConclusionsFor patients with human chorionic gonadotropin-secreting tumors, gonadotropin levels increase prior to sex steroid decrease, seems a sign of melatonin-related central PP related to melatonin.

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-β (Aβ) 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 Aβ 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 Aβ oligomers levels and phospho-tau by activating GnRHRs and their downstream signaling pathways.

Development of an acute ovine model of polycystic ovaries to assess the effect of ovarian denervation.

Polycystic ovary syndrome (PCOS) seems to be associated with increased ovarian sympathetic nerve activity and in rodent models of PCOS reducing the sympathetic drive to the ovary, through denervation or neuromodulation, improves ovulation rate. We hypothesised that sympathetic nerves work with gonadotropins to promote development and survival of small antral follicles to develop a polycystic ovary phenotype. Using a clinically realistic ovine model we showed a rich sympathetic innervation to the normal ovary and reinnervation after ovarian transplantation. Using needlepoint diathermy to the nerve plexus in the ovarian vascular pedicle we were able to denervate the ovary resulting in reduced intraovarian noradrenaline and tyrosine hydroxylase immunostained sympathetic nerves. We developed an acute polycystic ovary (PCO) model using gonadotrophin releasing hormone (GnRH) agonist followed infusion of follicle stimulating hormone (FSH) with increased pulsatile luteinising hormone (LH). This resulted in increased numbers of smaller antral follicles in the ovary when compared to FSH infusion suggesting a polycystic ovary. Denervation had no effect of the survival or numbers of follicles in the acute PCO model and did not impact on ovulation, follicular and luteal hormone profiles in a normal cycle. Although the ovary is richly inervated we did not find evidence for a role of sympathetic nerves in ovarian function or small follicle growth and survival.

Omega 3 fatty acid improves sexual and erectile function in BPF-treated rats by upregulating NO/cGMP signaling and steroidogenic enzymes activities

Bisphenol F (BPF) is an environmental pollutant that has been implicated in sexual dysfunction. Omega 3 fatty acid (O3FA), on the other hand, is an antioxidant with the ability to improve fertility indices. However, no study has explored the possible ameliorative effect of O3FA on BPF-induced sexual dysfunction. Thus, the effect of BPF and/or O3FA on male sexual performance was investigated. Male Wistar rats were randomized into 6 groups, corn oil-treated, O3FA low and high dose (100 and 300 mg/kg), BPF-treated, BPF + O3FA low and BPF + O3FA high dose. BPF significantly impaired male sexual competence, evidenced by a reduction in motivation to mate, prolonged mount, intromission and ejaculation latency, and post-ejaculatory index. Furthermore, a reduction in mount, intromission, and ejaculation frequency were observed. Also, BPF caused a decrease in gonadotropin releasing hormone, follicle stimulating hormone, luteinizing hormone, testosterone, nitric oxide (NO) cyclic guanosine monophosphate (cGMP), 3beta-hydroxysteroid dehydrogenase (3β-HSD), 17beta-hydroxysteroid dehydrogenase (17β-HSD), dopamine, and acetylcholine esterase. Furthermore, it was accompanied by a significant increase in prolactin and estrogen and poor pregnancy outcomes. These observed BPF-led alterations were abolished by O3FA administration. This study showed that O3FA ameliorates BPF-induced sexual dysfunction by upregulating NO/cGMP signaling and steroidogenic enzymes activities.

The natural cycle protocol of endometrial preparation for frozen embryo transfer decreases the miscarriage rate in women with recurrent pregnancy loss

Objective To investigate whether different endometrial preparation methods lead to different results. Design Retrospective cohort study. Patients Women with recurrent pregnancy loss undergoing frozen embryo transfer (FET). Interventions Natural cycle (NC) protocol (n = 111) with no drug or human chorionic gonadotropin (HCG) used for endometrial preparation, vs. the hormone replacement therapy (HRT) protocol (n = 797) with estrogen or gonadotropin releasing hormone agonist (GnRH-a) plus estrogen used for endometrial preparation. Main outcome measures Miscarriage rate and live birth rate (LBR). Results Compared to women in the HRT protocol, women undergoing NCs had fewer previous FET cycles, lower antral follicle counts (AFCs), fewer oocytes retrieved and a thicker endometrium on the day of progesterone administration. Women in the HRT group had a higher miscarriage rate (29.4% vs. 17.2%) and a lower LBR (37% vs. 46.9%) than the rates of women in the NC group. Univariate analysis showed that female age also had a negative association with the miscarriage rate. Logistic regression indicated that endometrial preparation using the NC protocol was linked to a decreased likelihood of miscarriage. Conclusions The NC protocol decreased the miscarriage rate and increased the LBR for patients with recurrent pregnancy loss compared with the HRT protocol.

THU193 Clinical Usefulness Of Repetitive GnRH Stimulation Test For The Diagnosis Of Central Precocious Puberty

Abstract Disclosure: S. Heo: None. Y. Shim: None. H. Lee: None. J. Hwang: None. J. Lim: None. Objective In girls, breast development under 8 years of age and peak serum luteinizing hormone (LH) is 5 IU/L or higher in gonadotropin releasing hormone (GnRH) stimulation tests is a standard method for diagnosing central precocious puberty (CPP). Although breast development and bone age progress rapidly compared to chronological age, repeated GnRH stimulation tests do not exceed 5 IU/L in some cases. We aimed to analyze the clinical characteristics of girls who repeatedly examined the GnRH stimulation test. Methods We retrospectively reviewed the medical records of 988 girls under 9 years of age who visited our hospital due to breast development more than Tanner stage II and whose bone age was more than a year advanced than the chronological age and examined GnRH stimulation test twice or more. According to peak luteinizing hormone (LH) at first GnRH stimulation test, patients were divided into 5 groups that &amp;lt; 1.0 IU/L (group 1, n=34), ≥1.0 to &amp;lt; 2.0 IU/L (group 2, n=219), ≥2.0 to &amp;lt; 3.0 IU/L (group 3, n=297), ≥3.0 to &amp;lt; 4.0 (group 4, n=252) and ≥4.0 to &amp;lt; 5.0 (group 5, n=186). We analyzed the incidence of CPP through the repetitive GnRH stimulation test and factors associated with the outcomes using a Cox proportional hazard model. Results Mean age of total of 988 girls was 7.68 ± 0.67 years and the period between the first and last GnRH stimulation test was 216.40 ± 145.14 days. CPP was diagnosed in 138 patients. Incidence of CPP were differed by groups that 0%, 1.4%, 6.1%, 20.6%, 34.9% each groups. When group 1 and each groups were compared using the Cox proportional hazard regression model, difference between bone age and chronological age (95% CI, 1.27-2.35, p&amp;lt;0.001) (BA-CA) and basal follicle-stimulating hormone (95% CI, 1.01-1.48, p=0.039) showed a statistically significant positive correlation when stratifying the peak LH at GnRH stimulation test. Conclusion In the diagnosis of CPP, the GnRH stimulation test is gold standard. But the lower the peak LH in GnRH stimulation test, the more other factors such as difference between bone age and chronological age, basal FSH should be considered in the possibility of CPP. Presentation: Thursday, June 15, 2023

SAT419 Characteristics Of Trans Male Children And Adolescents Care Followed Up In A Children Hospital

Abstract Disclosure: M. Esposito: None. V.G. Gonzalez: None. J. Pasqualotto: None. A. Morin: None. Introduction Transgender and gender diverse (TGD) people are those whose gender identity do not correspond with their sex assigned at birth. Gender identity law was approved in 2012, guarantees access to health care including hormones and surgical procedures reassignment without any requirement except "informed consent by the individual concerned". Last years the number of youth with TGD seeking gender affirming care has increased, resulting in the formation of multidisciplinary care teams to respond to the growing demand. Objective To characterize the population of transgender male(TM) attended in a Pediatric Endocrinology Service. Method Medical records of the Pediatric Endocrine Service were reviewed for youth with TGD seen from December 2017 to November 2022. Results We received 92 TGD individuals in our care team, of which 64 (69.6%) consulted in Endocrinology Service, 52 trans-male (TM) (81.3%) and 12 trans-female (TF) (18.7%). We describe TM group. Median age was calculated for first medical advice: 14 (9-16) years; self-perception TGD: 9 (3-14) years; and gender affirmation: 13 (6-16) years. Obesity and overweight was present in 22 (42.3%), normoweight in 25 (48%) and underweight in 5 (9.7%). Vitamin D levels (N: 35) were insufficient in 30 children (85.7%). At first visit 45 (86%) were in Tanner stage 5. Gonadotropin releasing hormone agonists (Gnrh) were used in 27 TM (51.9 %) to prevent the progression of biological puberty, median age at start of treatment was 14 (11-15) years. Testosterone (T) was used in 18 (34.6%) to develop sex characteristics of the self-identified gender, median age of beginning was 16 (14-17) years of which 12 have previously used GnRH. In 4 adolescents (7.7%) thoracic masculinization surgery was performed at a median age of 16 years. Conclusion Most of the TGD children and adolescents were TM with a median age at first visit of 14 years and tanner stage 5. Overweight and obesity rates were higher than international norms and are a common problem among TGD youth. They should be considered a high-risk group and targeted in obesity prevention and treatment efforts. The majority of transgender youth had vitamin D insufficiency, so we recommend sun exposure and physical activity. Although they consulted in the Pediatric Endocrinology Service, only 63.5% started some hormonal therapy. Gender affirmation require multidisciplinary approach in which endocrinologists play an important role. Presentation: Saturday, June 17, 2023

THU205 A Case Of Infant With Familial-Male Limited Precocious Puberty (FMPP) Inherited From Father Due To An Activating Mutation Of The Luteinizing Hormone/Chorionic Gonadotropin Receptor Gene

Abstract Disclosure: H. Yoo: None. J. Ha: None. M. Jung: None. Y. Choi: None. E. Yoo: None. We present an extremely rare case of FMPP with an activating mutation of the LHCGR gene in a Korean infant. A 16-month-old-boy was brought to the out-patient clinic with complaints of pubic hair, acne and rapid growth acceleration. His father had become aware of the symptoms 4 month before. His grandfather and father had a family history of precocious puberty and profound short stature (Height of grandfather and father: 148 cm and 158 cm respectively). At physical examination, his height was 83 cm (+1.2 SDS) and his weight was 14.3 kg (+2.8 SDS). The testicular volume was 2 mL and pubic hair was appropriate for Tanner stage 2. Stretched penile length was 7 cm (&amp;gt;2 SDS). He did not have any café au lait spots or hyperpigmentation. His bone age was significantly advanced to that of a 4 year old. Laboratory findings showed abnormally elevated serum testosterone (5.74 ng/mL) and slightly elevated α-fetoprotein (14.1 ng/ml; reference 0-10 ng/mL) with suppressed LH level (&amp;lt;0.07 mIU/mL). Serum levels of β-human chorionic gonadotropin, cortisol, 17-hydroxyprogesterone, androstenedione and dehydroepiandrosterone sulfate were within normal range. A gonadotropin releasing hormone (GnRH) stimulation test revealed a prepubertal response(peak LH 0.52). Brain magnetic resonance imaging study was reported to be normal. Ultrasound of the scrotum and adrenal gland were both normal. Due to the patient’s classic presentation and his family history of male-limited precocious puberty, a genetic analysis for LHCGR gene was performed. Molecular genetic analysis identified a pathogenic variant of LHCGR (c.1730 C&amp;gt;T, p.Thr577Ileu), which was previously reported in a FMPP patient. His father and paternal grand father also carry the same mutation. Anti-androgen treatment with bicalutamide (25mg/day) and aromatase inhibition with anastrozole (1mg/day) were initiated. After treatment, there was improvement in pubertal progression, accelerated growth velocity and rate of skeletal maturation without any specific side effects. Presentation: Thursday, June 15, 2023

THU182 Widening The Spectrum Of ABCC8-related Disease: Insulin-mediated Pseudoacromegaly

Abstract Disclosure: I.F. Machado: None. B.B. Mendonca: None. A. Latronico: None. M.Y. Nishi: None. L.G. Gomes: None. Introduction: Insulin-mediated pseudoacromegaly is a rare condition characterized by acromegaloid phenotype without excessive GH secretion in the context of severe hyperinsulinemia. Case report: A 10.5 years old girl with tall stature, obesity, acanthosis nigricans, neurosensorial hearing deficiency and acromegaloid features was referred for clinical investigation. She was born of non-consanguineous parents, full-term, with normal birth weight and stature. She had no history of neonatal hypoglycemia or in infancy. At six years of age, she presented marked accelerated growth velocity and weight gain resulting in bilateral slipped femoral epiphysis. She developed thelarche at 7 years old, and was treated with gonadotropin releasing hormone agonist (GnRHa) from 8-10.5 years. Hearing deficiency was diagnosed at 7 years of age. Her family history was remarkable for paternal sudden cardiac death at age 35. At physical examination, she had an acromegaloid facial appearance with a prominent forehead and jaw, large hands and feet, and severe acanthosis nigricans in neck and axillae. Her weight and height were 99.5 kgs (Z 8.8) and 170 cm (Z 4.6), respectively; target height was 1.66 m (Z 0,72) and BMI was 34.4 (Z 3.5). Her breast and pubic hair development were Tanner stage IV. Laboratory exams showed normal IGF-1 and random GH levels. There was an abnormal response of GH (2.63 ng/mL) following an oral glucose tolerance test (OGTT), considered as false positive in the context of obesity and puberty. Her brain magnetic resonance was normal. She had a hemoglobin glycated of 6.1% and very high basal insulin levels of 98 µUI/mL with a normal glucose value of 81 mg/dL and OGTT-120 minutes insulin levels &amp;gt; 1000 µUI/mL with glucose of 113 mg/dL. Exome sequencing analysis showed a heterozygous missense ABCC8 variant c.622G&amp;gt;A p.(Glu208Lys), located in an exonic hotspot, and allele frequency absent from gnomAD databases. The ACMG classified this variant as pathogenic. Pseudoacromegaly, a heterogeneous condition, is caused by multiple genetic and pathophysiological backgrounds. In insulin-mediated pseudoacromegaly, the defects are mainly associated with postreceptor insulin signaling and action. We described a new type of hyperinsulinemic pseudoacromegaly caused by a mutation in the ABCC8 gene, which encodes the sulfonylurea receptor, a member of the K(ATP) channel superfamily. This gene is associated with congenital hyperinsulinemia causing hypoglycemia, generally when in homozygous state. This clinical report illustrates a new phenotype associated with ABCC8 mutation, and identifies a new genetic cause of hyperinsulinemic pseudoacromegaly. Conclusion: We described a patient with insulin-mediated pseudoacromegaly associated with neurosensorial hearing deficiency caused by a dominant variant in the ABCC8 gene, defining a new genetic cause of this intriguing disorder. Presentation: Thursday, June 15, 2023

THU580 A Subset Of Migrating Cells Co-express Gonadotropin Releasing Hormone And Prokineticin Receptor 2 During Embryonic Development

Abstract Disclosure: A.E. Danku: None. C.F. Elias: None. A subset of migrating cells co-express gonadotropin releasing hormone and prokineticin receptor 2 during embryonic development Antoinette Danku and Carol F Elias. Neuroscience Graduate Program and Department of Molecular &amp; Integrative Physiology, University to Michigan. Reproductive vitality in humans is strongly influenced by developmental foundations. The successful migration of GnRH cells and the pulsatile secretion of gonadotropin releasing hormone (GnRH) drives pubertal onset and dictates long-term fertility outcomes. During development, GnRH neurons migrate from the nasal placode to the basal forebrain to reach their destination in the medial preoptic area (MPOA). Aberrant GnRH migration causes redirection of axonal projections to atypical brain regions and dysregulated GnRH secretion. Disruption of GnRH neuronal function causes infertility or reproductive dysfunction. These etiologies are grouped as isolated gonadotropin deficiencies (IGD). Kallmann’s syndrome (KS) is a pediatric IGD that manifests as anosmia and hormonal dysfunction that can result in pubertal delay or infertility. Children with KS often have mutations in prokineticin 2 (Prok2) or the cognate receptor (ProkR2).Prok2 and ProkR2 are required for the formation of the olfactory bulb in rodents and humans. Loss-of-function mutations in these genes also disrupts GnRH cell migration, but whether the activation of ProkR2 regulates the guidance of GnRH neurons to their final destination has not been defined. Previous studies suggested that GnRH and ProkR2 are expressed in distinct cells, but how the prokineticin system may alter GnRH migration is largely unknown. To gain insights into the underlying mechanisms associated with ProkR2-GnRH interaction and migration, we conducted single nuclei RNA sequencing in nasal-forebrain junction of embryos at embryonic day 16 (E16) and fluorescent in situ hybridization in three developmental time points: E14, E16, and E18 for validation and spatial evaluation. Using these methods, we were able to isolate GnRH and ProkR2 cells and sort their cell types into clusters. While these cells differ in their expression profiles, they both express genes associated with migration at E16. Our findings suggest that ProkR2 cells in the nasal-forebrain junction migrate along with GnRH cells. Additionally, a subset of these migrating cells co-express ProkR2 and GnRH mRNA. Further studies are needed to determine whether this subset of cells take on specialized roles in GnRH cell migration and maturation. Presentation: Thursday, June 15, 2023

FRI275 Glutamate Receptor Agonists Stimulate Kisspeptin Neurons In The Arcuate Nucleus Of The Hypothalamus

Abstract Disclosure: R. Bearss: None. R. Piet: None. KNDy neurons co-express kisspeptin, neurokinin B (NKB), dynorphin A (Dyn A), and glutamate. These neurons, located in the arcuate nucleus of the hypothalamus, drive pulsatile gonadotropin releasing hormone (GnRH) secretion. This eventually promotes pulsatile gonadotropin hormone release from the anterior pituitary, important for fertility in both sexes. The current hypothesized mechanism for pulse generation involves KNDy neuron interconnectivity and reciprocal regulation through the combined actions of NKB, DynA and glutamate to coordinate KNDy neuron activity. There is evidence that KNDy neurons express NKB, Dyn A and glutamate receptors and that NKB stimulates KNDy neuron electrical activity while Dyn A suppresses it. There is also evidence that ionotropic glutamate receptor antagonists can inhibit KNDy neuron coordinated activity and pulsatile gonadotropin hormone release, indicating that glutamatergic neurotransmission plays a significant role in activity coordination. The purpose of the following experiments was to investigate the response of KNDy neurons to varied glutamate receptor activation. We used calcium imaging to monitor the activity of KNDy neurons in brain slices. We crossed Kiss1-Cre mice—expressing Cre recombinase (Cre) in kisspeptin neurons—with Cre-dependent GCaMP6f mice to generate Kiss1-Cre x GCaMP6f mice that express GCaMP6f in kisspeptin neurons. GCaMP6f fluorescence increases when binding to intracellular calcium and can, thus, be used as an inferential marker of electrical activity. Coronal brain slices (200 µm thickness) obtained from male Kiss1-cre x GCaMP6f mice and containing the arcuate nucleus were placed in a recording chamber under an epifluorescence microscope. KNDy neurons were exposed for 2 minutes to a bath application of either the ionotropic glutamate receptor agonist α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA, 10µM), the ionotropic glutamate receptor agonist N-methyl-D-aspartate (NMDA, 50µM), or the group 1 metabotropic glutamate receptor (mGluR) agonist (S)-3,5-dihydroxyphenylglycine (DHPG, 50µM). AMPA, NMDA, and DHPG increased KNDy neuron fluorescence by 7.8±0.5% (n=113 in 7 slices from 6 mice), 7.5±0.5% (n=154 in 6 slices from 5 mice), and 6.1±0.7% (n=159 in 7 slices from 5 mice) respectively. All cells that were excited by NMDA or DHPG were also excited by AMPA. These experiments provide evidence that activation of ionotropic AMPA and NMDA receptors as well as group 1 mGluRs stimulate KNDy neuron activity. Further investigation into the precise role of individual glutamate receptor subtypes on KNDy neuron coordinated activity is needed. Presentation: Friday, June 16, 2023

Dual trigger for final oocyte maturation in expected normal responders with a high immature oocyte rate: a randomized controlled trial.

To evaluate whether dual trigger could improve reproductive outcomes in women with low oocyte maturation rates compare to human chorionic gonadotropin (hCG) trigger. This study included expected normal ovarian responders younger than 40 years old whose immature oocyte rate in the previous cycle was more than 50% at the reproductive center from July 2021 to November 2022. A total of 73 patients were enrolled at trigger, including 34 in the hCG trigger group and 39 in the dual trigger group (co-administration of gonadotrophin releasing hormone (GnRH) agonist and hCG, 40 and 34 h prior to oocyte retrieval, respectively). The primary outcome was oocyte maturation rate. There was no significant difference in the number of oocytes retrieved between the two study groups, but the oocyte maturation rate was higher in dual trigger group (84.0% [14.0%] vs. 55.5% [19.8%], p < 0.001). Moreover, there were also higher cumulative pregnancy rate (69.4% vs. 40.0%, p = 0.035) and cumulative live birth rate (66.7% vs. 36.0%, p = 0.022) in dual trigger group. For normal responders with low oocyte maturation rates, the dual trigger may be more effective than the conventional hCG trigger. ClinicalTrials.gov, identifier ChiCTR2100049292.

Physiological role of dietary energy in the sexual maturity: clues of body size, gonad development, and serum biochemical parameters of Chinese indigenous chicken

Sexual maturity is a crucial factor in the formation and development of poultry reproductive capacity. The nutritional status has been confirmed to play an important role in the regulation of sexual maturity. To investigate the effect of dietary energy levels on sexual maturity in chicken, diets with 3 energy levels (group L: 2,573 kcal/kg, group C: 2,836 kcal/kg, group H: 3,122 kcal/kg) were implemented to feed Guangyuan Gray chickens. During this trial, body weight, body size, organ development, sexual maturity, reproductive performance and blood biochemical parameters were monitored. The earlier sexual maturity was observed in group H, as well as a heavier first egg weight, larger interpubic distance and higher total cholesterol (T-CHO) content at sexual maturity. The dietary energy levels had no significant effect on body weight at first egg and egg production at 300 d of age. Although dietary energy levels had a significant effect on body weight, comb length, tibia length and girth, abdominal fat weight, oviduct weight and length, T-CHO, triglyceride (TG) content and estradiol (E2) level during the rearing period. No significant difference of gonadotropin releasing hormone (GnRH) and luteinizing hormone (LH) level among 3 groups was observed during the trial. The dietary energy levels had effects on mRNA expression of GnRH, estrogen receptor 1 (ESR1), estrogen receptor 2 (ESR2) in hypothalamus, gonadotropin inhibitory hormone receptor (GnIHR) in pituitary and luteinizing hormone receptor (LHR), ESR2 in ovary. The GnIHR/GnRHR ratio in pituitary was higher before sexual maturity and decreased at sexual maturity. The results of correlations analysis found that all the body size, carcass traits, serum biochemical parameters negatively correlated with age at first egg except for interpubic distance and serum blood glucose content. Collectively, dietary energy levels had effects on sexual maturity of chicken, which may be achieved by affecting body weight, gonad development, endocrine and the mRNA expression of genes related to hypothalamus-pituitary-gonad axis. These results further set our understanding of how dietary energy regulates sexual maturity.

Bothersome Gynecomastia Following Neoadjuvant GnRH Agonists and Stereotactic Body Radiotherapy for Localized Prostate Cancer

Androgen deprivation therapy (ADT) is increasingly utilized in combination with stereotactic body radiotherapy (SBRT) for unfavorable prostate cancer. ADT such as gonadotropin releasing hormone (GnRH) agonists are known to cause hormonal-related side effects such as gynecomastia. The incidence of bothersome breast tenderness and/or enlargement following short course GnRH agonists and SBRT is unknown. This study sought to evaluate the timeline of gynecomastia as well as its relationship with testosterone recovery. Gynecomastia was self-reported via question 13b of a healthcare software prior to ADT initiation, the first day of robotic SBRT, and at each follow-up (1, 3, 6, 9, 12, 18, 24 and 36 months). The responses were grouped into three relevant categories (no problem, very small-small problem, and moderate-big problem). Scores were transformed to a 0-100 scale with higher scores reflecting less bother. Testosterone levels were measured at each follow-up. From 2007 to 2010, 122 localized prostate cancer patients (9 low-, 64 intermediate-, and 49 high-risk according to the D'Amico classification) at a median age of 72 years (range 54.5-88.3) were treated with short course ADT (3-6 months) and SBRT (35-36.25 Gy) at Georgetown University Hospital. Of the participants, 48% percent were non-white and 48% were overweight. 77% of patients received three months of ADT. At baseline, 2% of men experienced gynecomastia that was a "moderate to big problem" and that proportion peaked at 3 and 12 months post-SBRT (7%) before returning to less than baseline (0%) 24 months post-SBRT with a cumulative incidence of 14.75%. The median baseline healthcare software hot flash score of 98 declined to 90 at 3 months post-SBRT but this returned to baseline by 24 months post SBRT. These changes were both statistically and clinically significant (MID = 6.5). Testosterone recovery (> 230 ng/dL) occurred in approximately 70% of patients by 12 months post SBRT. The development and resolution of gynecomastia fluctuated at various timepoints and did not directly correlate with testosterone recovery. Bothersome gynecomastia occurs in less than 15% of men treated with neoadjuvant ADT. Resolution of gynecomastia occurs in most patients within two years after treatment. Reassurance of the temporary nature of gynecomastia may assist in reducing patient anxiety. Institutional IRB (IRB#: 2009-510) approval was obtained for retrospective review of prospectively collected data.

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.