Gonadotropin-releasing Hormone Research Articles

100 Impact of luteal blood perfusion and estrus expression on pregnancy rates of beef cows exposed to embryo transfer

Abstract This study aimed to evaluate the impact of luteal blood perfusion and estrus expression on pregnancy rates of beef cows exposed to fixed-timed embryo transfer (FTET). Postpartum beef cows (n = 763) from 22 locations were exposed to a 7-d Select Synch + controlled internal drug releasing (CIDR) and breeding indicator patches were affixed upon CIDR removal. Estrus expression was assessed twice daily for 72 h and a 100-µg injection of gonadotropin-releasing hormone was administered to cows that failed to express estrus 72 h after CIDR removal. Brightness mode ultrasonography of the corpus luteum (CL) was conducted to select recipients for FTET 9 d after CIDR removal. Suitable recipients were assigned to receive a single fresh or frozen embryo derived from either in vitro (IVF) or in vivo (IVD) method. After embryo recipient selection, CL morphometries and blood perfusion (BP) were then assessed at the time of embryo transfer via transrectal ultrasonography. Embryo recipients were categorized according to CL area [small (< 3 cm²), medium (3 to 4 cm²), or large (> 4 cm²)] and based on the percentage of luteal area with blood perfusion signals [low (< 25%), medium (25 to 45%), or high (> 45%)]. Pregnancy diagnoses were performed between d 60 and 90 of gestation. Cows that failed to express estrus prior FTET had decreased (P ≤ 0.02) luteal area, luteal diameter, and pregnancy rates compared with cows that expressed estrus. Luteal area category had no effect (P = 0.61) on pregnancy rates. Embryo recipients that expressed estrus had similar (P = 0.12) luteal blood perfusion compared with recipients that failed to express estrus. Embryo recipients with high (P = 0.02) and medium (P = 0.05) BP had greater pregnancy rates compared with embryo recipients with low BP. There was no interaction between estrus expression and luteal BP (P = 0.84). In summary, estrus expression and luteal BP positively impacted pregnancy rates to embryo transfer and may be used to facilitate embryo recipient selection.

Effects of management of heavy menstrual bleeding of patients undergoing haploidentical hematopoietic stem cell transplantation.

To investigate the benefits of menstrual management in women undergoing hematopoietic stem cell transplantation (HSCT), in whom heavy menstrual bleeding (HMB) can be an underestimated bleeding complication. This was a retrospective cohort study. Patients who had undergone HSCT in the Gynecological Endocrinology Clinic of Peking University People's Hospital were included over 10 years. The data of hematology and menstruation for all participants were collected. The management methods of the intervention group include gonadotropin-releasing hormone agonists (GnRHa), combined oral contraceptives (COC), or low-dose mifepristone. Patients who did not receive management were included in the control group. There were 112 patients included in the intervention group and 218 patients included in the control group. In all, 90.0%(297/330) of patients presented with HMB before HSCT. In the control group, 83.5%(182/218)of patients experienced menstruation in the laminar air-flow room (LAFR), whereas only 22.3%(25/112) did in the intervention group. After leaving the LAFR, the incidence of recurrent uterine bleeding was significantly reduced in the intervention group (17.9%(20/112/)versus 50.9%(111/218), p < 0.001). Patients who did not undergo menstrual management had a higher risk of bleeding than those who did (odds ratio 18.12, p < 0.001). Menstrual management significantly reduces the incidence of HMB in HSCT patients and acts as a protective factor to prevent menstrual bleeding in the LAFR.

Comparison of ultra-long gonadotropin releasing hormone agonist versus standard downregulation in women with adenomyosis undergoing frozen-thawed embryo transfer: a randomized clinical trial

BackgroundAdenomyosis can lead to infertility and failure of in vitro fertilization. Limited evidence suggests that the use of long-term treatment with gonadotropin-releasing hormone (GnRH) agonists followed by frozen-thawed embryo transfer (FET) may be the preferred approach for women with adenomyosis.ObjectiveThe aim of this randomized controlled trial is to compare the efficacy of an ultra-long GnRH agonist with standard downregulation in women with adenomyosis undergoing FET.Materials and methodsThis randomized controlled trial enrolled 72 women with adenomyosis diagnosed by sonographic criteria who underwent FET cycles at the Avicenna Infertility Center. These women were randomly assigned to two equal groups: one received GnRH agonist treatment for three months before the FET cycle and the other served as the standard downregulation group. Results were reported as chemical and clinical pregnancy rates.ResultsThe two groups were similar in age, body mass index, anti-Müllerian hormone levels, number of previous pregnancies and miscarriages, presence of uterine myomas, and endometriosis. However, the total dose of estradiol used until embryo transfer was significantly higher in the ultra-long GnRH agonist group than in the standard group (96.14 mg vs. 80.52 mg, p-value = 0.004). Nevertheless, chemical and clinical pregnancy rates did not differ significantly between the two groups.ConclusionsUltra-long GnRH agonist downregulation did not improve the chemical and clinical pregnancy rate in the FET cycle in women with adenomyosis compared with standard GnRH agonist downregulation in the other words, ultra-long GnRH agonist downregulation is not superior to standard protocol. In women with adenomyosis (without history of endometriosis), downregulation of standard GnRH agonists prior to frozen-thawed embryo transfer may be the preferred embryo transfer protocol to gain higher clinical/chemical pregnancy rate.Trial registrationClinical trial registry: IRCT20160717028967N9, available at: https://irct.behdasht.gov.ir/trial/36103.

The Protective Effect of GnRH Agonist Triptorelin on the Histomorphometric Parameters of the Utero-ovarian Tissue in the Doxorubicin- and Cyclophosphamide-treated Mice.

One of the common side effects of chemotherapy drugs is ovarian failure and uterine dysfunction, which can occur after the administration of doxorubicin and/or cyclophosphamide. In clinics, gonadotropin-releasing hormone agonists (GnRHa) are used to modulate the toxic effect of chemotherapy and intercept infertility with some controversy and limited histological knowledge. This study aimed to evaluate the serological and histological features of protective effects of triptorelin, (GnRHa), on utero-ovarian tissue in the mice treated with cyclophosphamide and/or doxorubicin. Forty-eight female BALB/c mice were randomly divided into 8 groups as follows: Group I: normal saline; Group II: triptorelin; Group III: cyclophosphamide; Group IV: doxorubicin; Group V: cyclophosphamide + doxorubicin; and Groups VI, VII, and VIII: after injection of cyclophosphamide, doxorubicin, or cyclophosphamide + doxorubicin, administration of triptorelin (1 mg/kg; intraperitoneally) for 15 consecutive days, respectively. On the 21st day, the ovaries and uterine horns were dissected and weighed. Then, tissue processing and staining were performed for further histological and stereological studies. Triptorelin treatment in the damaged groups significantly increased the number of primordial and pre-antral follicles and granulosa cells. It decreased the number of atretic follicles compared to cyclophosphamide and/or doxorubicin-treated groups (P < 0.05). Triptorelin also significantly improved the volume of the ovary, cortex, medulla, oocytes in the primordial and antral follicles, uterus, endometrium, myometrium, uterine glands, and endometrial blood vessels in the damaged groups (P < 0.05). Triptorelin treatment prevents the destructive effects of cyclophosphamide and/or doxorubicin on utero-ovarian tissue.

Effects of Heat Stress-Induced Sex Hormone Dysregulation on Reproduction and Growth in Male Adolescents and Beneficial Foods.

Heat stress due to climate warming can significantly affect the synthesis of sex hormones in male adolescents, which can impair the ability of the hypothalamus to secrete gonadotropin-releasing hormone on the hypothalamic-pituitary-gonadal axis, which leads to a decrease in luteinizing hormone and follicle-stimulating hormone, which ultimately negatively affects spermatogenesis and testosterone synthesis. For optimal spermatogenesis, the testicular temperature should be 2-6 °C lower than body temperature. Heat stress directly affects the testes, damaging them and reducing testosterone synthesis. Additionally, chronic heat stress abnormally increases the level of aromatase in Leydig cells, which increases estradiol synthesis while decreasing testosterone, leading to an imbalance of sex hormones and spermatogenesis failure. Low levels of testosterone in male adolescents lead to delayed puberty and incomplete sexual maturation, negatively affect height growth and bone mineral density, and can lead to a decrease in lean body mass and an increase in fat mass. In order for male adolescents to acquire healthy reproductive capacity, it is recommended to provide sufficient nutrition and energy, avoid exposure to heat stress, and provide foods and supplements to prevent or repair testosterone reduction, germ cell damage, and sperm count reduction caused by heat stress so that they can enter a healthy adulthood.

Low concentrations of the food contaminant Deoxynivalenol trigger apoptosis and impair GnRH-induced LH secretion in pituitary gonadotrope-like cells.

AbstractTheFusariummycotoxin deoxynivalenol (DON) is one of the most frequently occurring food contaminants. Nearly all individuals are exposed to DON, due to it widespread presence in grains and grain-based products. Chronic DON poisoning is associated with growth retardation, immunotoxicity as well as impaired reproduction and fetal development. At the molecular level, DON alters intracellular signaling by activating mitogen-activated protein kinases (MAPKs) that modulate cell growth, differentiation, and apoptosis. Of note, these MAPKs are also critical mediators of gonadotrophin-releasing hormone (GnRH)-induced synthesis and secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) by pituitary gonadotrope cells. So far, no research has explored the potential endocrine-disrupting effects of DON on pituitary gonadotropins production. Herein, we show the first evidence that DON affects LH production by the immortalized gonadotrope-like cell line LβT2 in a concentration-dependent manner. Taken together, our experiments demonstrated that low concentrations of DON affect GnRH-induced signaling through a mechanism that, at least in part, involves apoptosis and inhibition of GnRH-induced phosphorylation of ERK-MAPK. Consequently, DON also affects the GnRH-induced expression ofCgaandLhb, two critical genes for LH synthesis and secretion by gonadotrope cells in mammals. This research broadens our knowledge of the toxicity of DON and brings a new depth to the potential neuroendocrine implications for reproduction.Graphical abstract

Effects of pretreatment with long-acting gonadotropin-releasing hormone agonists on pregnancy outcomes in patients with minimal and mild peritoneal endometriosis: A retrospective study of 274 frozen-thawed embryo transfer cycles.

To investigate the effects of pretreatment with long-acting gonadotropin-releasing hormone agonist (GnRH-a) before frozen-thawed embryo transfer (FET) on pregnancy outcomes in patients after minimal-mild (stages I-II) peritoneal endometriosis surgery. A retrospective cohort study was performed from March 2018 to May 2019. Overall, 274 patients met inclusion criteria of undergoing FET after minimal/mild peritoneal endometriosis surgery. For the FET protocol, patients were divided into 2 groups: GnRH-a plus hormone replacement therapy (HRT) (group A, n = 154) and HRT-only (group B, n = 120), with the former divided into 2 subgroups receiving 1 (group A1, n = 80) or 2 doses (group A2, n = 74) of GnRH-a. Basic characteristics and pregnancy outcomes of groups A and B and groups A1 and A2 were compared. Clinical pregnancy rate (CPR) and live birth rate (LBR) were the primary outcomes and logistic regression was used to analyze independent correlation factors. The CPR and LBR in group A were 58.4% and 50.0%, respectively, and were not significantly higher than in group B (49.2% and 40.0%; respectively, χ2 = 2.339, P = .126 and χ2 = 2.719, P = .099, respectively). CPR and LBR in group A1 were not significantly lower than those in group A2 (52.5% and 45.0% vs 64.9% and 55.4%, respectively; χ2 = 2.420, P = .120 and χ2 = 1.665, P = .197, respectively). However, group A2's CPR and LBR were significantly higher than group B's (64.9% and 55.4% vs 49.2% and 40.0%, respectively; χ2 = 4.560, P = .023 and χ2 = 4.375, P = .026, respectively). Logistic regression analysis showed that GnRH-a pretreatment (1 or 2 doses) had no significant effect on CPR and LBR compared with the HRT-only group. Patients with minimal-mild (stages I-II) peritoneal endometriosis surgery may not require GnRH-a pretreatment before FET.

Might retrigger with human chorionic gonadotropin be a solution for empty follicle syndrome after gonadotropin releasing hormone agonist trigger?

This study aimed to determine whether the use of human chorionic gonadotropin (hCG) as a trigger could offer a potential solution for addressing empty follicle syndrome following the administration of a trigger for gonadotropin-releasing hormone agonist. A retrospective cohort analysis was conducted using data extracted from the hospital database pertaining to 415 patients who underwent in vitro fertilization (IVF) with an antagonist protocol triggered by a gonadotropin-releasing hormone (GnRH) agonist between December 2019 and January 2023 at the Acıbadem Maslak Hospital Assisted Reproductive Technologies Unit. All cases that failed to obtain oocytes and required rescue were analyzed. This study analyzed 415 women who underwent IVF using GnRH agonist-triggered antagonist protocols. Among them, 6 (1.4%) had empty folicle syndrome (EFS). Patients with EFS had lower luteinizing hormone levels and fewer oocytes, embryos, and blastocysts, resulting in lower oocyte utilization rate. However, pregnancy rates were similar, with no biochemical or ectopic pregnancies observed in the EFS group. Use of an hCG retrigger in hyperresponders with no oocytes after GnRHa trigger may prevent cycle cancelation. Although the rates of egg utilization may decrease, oocyte maturity remains comparable. Frozen embryo transfer following hCG retrigger administration yields similar positive pregnancy test results and live birth rates.

Estradiol elicits distinct firing patterns in arcuate nucleus kisspeptin neurons of females through altering ion channel conductances.

Hypothalamic kisspeptin (Kiss1) neurons are vital for pubertal development and reproduction. Arcuate nucleus Kiss1 (Kiss1ARH) neurons are responsible for the pulsatile release of Gonadotropin-releasing Hormone (GnRH). In females, the behavior of Kiss1ARH neurons, expressing Kiss1, Neurokinin B (NKB), and Dynorphin (Dyn), varies throughout the ovarian cycle. Studies indicate that 17β-estradiol (E2) reduces peptide expression but increases Vglut2 mRNA and glutamate neurotransmission in these neurons, suggesting a shift from peptidergic to glutamatergic signaling. To investigate this shift, we combined transcriptomics, electrophysiology, and mathematical modeling. Our results demonstrate that E2 treatment upregulates the mRNA expression of voltage-activated calcium channels, elevating the whole-cell calcium current and that contribute to high-frequency burst firing. Additionally, E2 treatment decreased the mRNA levels of Canonical Transient Receptor Potential (TPRC) 5 and G protein-coupled K+ (GIRK) channels. When TRPC5 channels in Kiss1ARH neurons were deleted using CRISPR, the slow excitatory postsynaptic potential (sEPSP) was eliminated. Our data enabled us to formulate a biophysically realistic mathematical model of the Kiss1ARH neuron, suggesting that E2 modifies ionic conductances in Kiss1ARH neurons, enabling the transition from high frequency synchronous firing through NKB-driven activation of TRPC5 channels to a short bursting mode facilitating glutamate release. In a low E2 milieu, synchronous firing of Kiss1ARH neurons drives pulsatile release of GnRH, while the transition to burst firing with high, preovulatory levels of E2 would facilitate the GnRH surge through its glutamatergic synaptic connection to preoptic Kiss1 neurons.

Significance of FSHR and LHCGR gene polymorphisms on clinical outcomes in gonadotropin-releasing hormone antagonist protocol with freeze-all strategy: A case-control study.

Follicle-stimulating hormone receptor (FSHR) and luteinizing hormone/choriogonadotropin receptor (LHCGR) are integral to ovarian function, facilitating follicle development and maturation through their respective hormonal interactions. The influence of receptor polymorphisms on the outcomes of freeze-all cycles remains unclear. This study investigates the impact of FSHR N680S and LHCGR N312S polymorphisms on clinical outcomes in freeze-all cycles. Women undergoing controlled ovarian stimulation for assisted reproductive technology participated in this study. They were administered a gonadotropin-releasing hormone antagonist protocol, with recombinant follicle-stimulating hormone (rFSH) dosages adjusted according to age, body mass index, antral follicle count, and individual hormonal responses. Additionally, human menopausal gonadotropin dosages were tailored based on the LHCGR N312S genetic variant. Analysis revealed no significant differences in age, body mass index, antral follicle count, or marital status across the genotypes of FSHR N680S and LHCGR N312S. However, notable differences were observed in the rFSH dosage required daily and in total among the FSHR polymorphism genotypes. Genotypes of the LHCGR polymorphism correlated with fewer stimulation days. A significant interaction was observed between the 2 polymorphisms concerning total rFSH dosage. The presence of serine in the FSHR polymorphism was associated with higher rFSH dosage requirements. Both FSHR N680S and LHCGR N312S polymorphisms significantly influenced clinical pregnancy and live birth outcomes in freeze-all cycles, underscoring the potential of a pharmacogenomic approach to optimize hormone supplementation in controlled ovarian stimulation protocols during assisted reproductive technology treatments.

GnRH-a-based fertility-sparing treatment of atypical endometrial hyperplasia (AEH) and early endometrial carcinoma (EC) patients: a multicenter, open-label, randomized designed clinical trial protocol

BackgroundAround 4% of women receive an endometrial cancer diagnosis before turning 40, mainly those without prior childbirth experience and a strong desire to preserve their ability to conceive. Consequently, for young patients diagnosed with atypical endometrial hyperplasia (AEH) or early endometrial carcinoma (EC), a fertility-preserving approach employing high-dose oral progesterone has been adopted. However, previous research has shown a notable relapse rate. Furthermore, the extended use of substantial oral progesterone doses may hinder ovarian function and raise the risk of weight gain, liver issues, blood clotting, and breast cancer. We previously assessed the clinical effectiveness and pregnancy outcomes of gonadotropin-releasing hormone agonist (GnRH-a) based re-treatment for women with EC and AEH who did not respond to oral progestin therapy but achieved favorable treatment results and reproductive outcomes.MethodsThis study will be an open-label, two-armed, randomized, investigator-initiated multicenter trial evaluating the combination of GnRH-a with the levonorgestrel-releasing intrauterine system or the combination of GnRH-a with an aromatase inhibitor (comprising a subcutaneous GnRH-a injection every 4 weeks and daily oral letrozole 2.5 mg). A total of 226 participants will be randomly allocated to one of the two treatment groups in a 1:1 ratio. The primary objective is to determine the effectiveness of GnRH-a-based re-treatment in achieving a complete response (CR) at 24 weeks for patients with AEH or EC. Secondary objectives include assessing the pregnancy rate 12 weeks after treatment, as well as post-treatment pregnancy outcomes and the rate of recurrence.Ethics and disseminationThe protocol received approval from the Institutional Review Board of Peking Union Medical College Hospital and from boards at five other institutions. The trial will adhere to the principles outlined in the World Medical Association’s Declaration of Helsinki and follow Good Clinical Practice standards. The trial results will be disseminated through publication in a peer-reviewed journal.ConclusionsProspective evidence supporting conservative treatment for EC and AEH is limited. There is a need for new approaches that can achieve higher CR rates with fewer side effects. This trial will assess the effectiveness of GnRH-a-based fertility-sparing treatment in obese women and recurrent patients, offering a promising alternative for patients with EC and AEH.Trial registration numberChinese Clinical Trial Registry ChiCTR2200067099. Registered on December 27, 2022.

Local Regulatory Changes of HSD11B1 and NR3C1 in the Follicular and Luteal Tissue During Experimentally Induced Ovulation in the Cow.

The objective of the study was to characterise the expression patterns of the two key components of cortisol action namely HSD11B1 (11-beta-hydroxysteroid dehydrogenase type 1) and NR3C1 (nuclear receptor subfamily 3, group C, member 1, also known as the glucocorticoid receptor) in superovulation induced bovine follicles during the periovulation and subsequent corpus luteum (CL) formation. Bovine ovaries containing preovulatory follicles or CL were timely defined during induced ovulation as follows: 0 h before GnRH (Gonadotropin-releasing hormone) application, and 4, 10, 20, 25 (follicles) and 60 h (early CL) after GnRH. The low mRNA expression of HSD11B1 and NR3C1 in the follicle group before the GnRH application increased significantly in the follicle group 20 h after GnRH and remained high afterward also in the early CL group. In contrast, the high NR3C1 mRNA decreased in follicles 25 h after GnRH (close to ovulation) and significantly increased again after ovulation (early CL). Our results indicated the involvement of HSD11B1 and NR3C1 as the two key components of cortisol action in the local mechanisms coordinating final follicle maturation, ovulation, follicular-luteal transition and CL development in the cow.

A GnRH neuronal population in the olfactory bulb translates socially relevant odors into reproductive behavior in male mice.

Hypothalamic gonadotropin-releasing hormone (GnRH) neurons regulate fertility and integrate hormonal status with environmental cues to ensure reproductive success. Here we show that GnRH neurons in the olfactory bulb (GnRHOB) of adult mice can mediate social recognition. Specifically, we show that GnRHOB neurons extend neurites into the vomeronasal organ and olfactory epithelium and project to the median eminence. GnRHOB neurons in males express vomeronasal and olfactory receptors, are activated by female odors and mediate gonadotropin release in response to female urine. Male preference for female odors required the presence and activation of GnRHOB neurons, was impaired after genetic inhibition or ablation of these cells and relied on GnRH signaling in the posterodorsal medial amygdala. GnRH receptor expression in amygdala kisspeptin neurons appear to be required for GnRHOB neurons' actions on male mounting behavior. Taken together, these results establish GnRHOB neurons as regulating fertility, sex recognition and mating in male mice.

A local audit evaluating bone health in patients with functional hypothalamic amenorrhoea secondary to an eating disorder and a review of the application of hormone therapy in this clinical setting.

It is widely known that estrogen has a fundamental role to play in skeletal homeostasis. In the most reductionist sense, the action of estrogen can be surmised as anti-resorptive. Estrogen prevents the break-down of bone. It therefore follows that estrogen deficiency states, such as the menopause and functional hypothalamic amenorrhoea (FHA), are often characterised by increased bone remodelling and disrupted skeletal homeostasis. FHA is the cessation of menstruation secondary to abnormal signalling between the hypothalamus and pituitary gland due to deficient pulsatile secretion of Gonadotrophin Releasing Hormone (GnRH). Functional hypothalamic amenorrhoea is frequently a consequence of women suffering with eating disorders. The development of FHA secondary to eating disorders is an evolutionary adaptive response to chronic metabolic energy deficiency. Fundamentally, preservation of life is biologically prioritised over dispensable physiological process such as reproduction. Consequently, the hypothalamic-pituitary-ovarian (HPO) axis fails, which disrupts menstrual function and ovulation, culminating in a state of estrogen deficiency. One of the most important and long-lasting deleterious consequences of FHA is disrupted skeletal homeostasis and bone loss. Estrogen replacement, most commonly in the form of combined hormone replacement therapy (HRT) or the combined oral contraceptive pill (COCP), is advised for women with an early menopause to prevent bone loss. Arguably, estrogen replacement should also be utilised in the context of FHA. However, the optimum estrogen regime for women with FHA remains under-researched and so management is not evidence-based.

Eje hipotálamo-hipofisario. Regulación neurohormonal, implicaciones patológicas, pruebas funcionales hipofisarias, indicaciones e interpretación

The hypothalamic-pituitary axis is a crucial system for maintaining homeostasis by integrating hormonal and neuronal inputs and outputs. Almost all bodily functions are regulated directly or indirectly by this axis. The hypothalamus, a small but vital brain region, monitors various inputs and maintains physiological set points through hormonal secretion, coordinating with the pituitary gland. This regulation involves multiple feedback mechanisms and interactions with other brain areas.The hypothalamus is anatomically divided into several regions and nuclei, each with specific functions. It produces a variety of hormones, including growth hormone-releasing hormone, corticotropin-releasing hormone, thyrotropin-releasing hormone, and gonadotropin-releasing hormone. These hormones regulate the secretion of corresponding hormones from the anterior pituitary gland, which control several physiological processes, including growth, metabolism, reproduction, and stress response.Pathological implications of hypothalamic-pituitary axis dysfunctions include endocrine disorders such as hyperprolactinemia, growth hormone deficiency, and hypogonadism. In addition, hypothalamic damage can lead to neurological and behavioral problems such as sleep disturbances and thermoregulation.

Contraceptive effect of a gonadotropin-releasing hormone vaccine on captive male brown bears (Ursus arctos).

Fertility control has traditionally been applied in zoos to control captive populations, and reversible contraception is important. However, contraceptive methods for male bears have not been reported. We aimed to establish a reversible contraceptive for male brown bears by investigating the effects of a gonadotropin-releasing hormone (GnRH) vaccine (Improvac®) that was developed for the immune castration of pigs. We vaccinated six bears with two sequential doses of 400 (n = 2) or 600 μg Improvac® (n = 4) with a 1-month interval during the pre-breeding season (February to April). We compared the reproductive parameters (testosterone levels and semen parameters) of the six vaccinated and four non-vaccinated (control) bears once during the breeding season (May or June). To investigate whether the reproductive performance could be restored in the following year of contraception, we also compared the reproductive parameters once during the breeding season in two bears between the year with GnRH vaccination and the following year without vaccination. Vaccination treatments suppressed reproductive parameters in 5 bears, although vaccination with 400 μg of Improvac® was not effective in one bear. Testosterone levels and the rate of progressive sperm motility were significantly lower, and total sperm count and testis size tended to be lower in vaccinated bears, compared with the controls. Blood biochemical findings and direct observations after Improvac® vaccination did not reveal side effects. Moreover, testosterone levels and spermatogenic scores of two bears were restored in the following year. We confirmed that the Improvac® vaccine elicited a reversible contraceptive effect in male brown bears.

Diversity of Molecular Functions of RNA-Binding Ubiquitin Ligases from the MKRN Protein Family.

Makorin RING finger protein family includes four members (MKRN1, MKRN2, MKRN3, and MKRN4) that belong to E3 ubiquitin ligases and play a key role in various biological processes, such as cell survival, cell differentiation, and innate and adaptive immunity. MKRN1 contributes to the tumor growth suppression, energy metabolism, anti-pathogen defense, and apoptosis and has a broad variety of targets, including hTERT, APC, FADD, p21, and various viral proteins. MKRN2 regulates cell proliferation, inflammatory response; its targets are p65, PKM2, STAT1, and other proteins. MKRN3 is a master regulator of puberty timing; it controls the levels of gonadotropin-releasing hormone in the arcuate nucleus neurons. MKRN4 is the least studied member of the MKRN protein family, however, it is known to contribute to the Tcell activation by ubiquitination of serine/threonine kinase MAP4K3. Proteins of the MKRN family are associated with the development of numerous diseases, for example, systemic lupus erythematosus, central precocious puberty, Prader-Willi syndrome, degenerative lumbar spinal stenosis, inflammation, and cancer. In this review, we discuss the functional roles of all members of the MKRN protein family and their involvement in the development of diseases.

Pulsatile gonadotropin-releasing hormone therapy: comparison of efficacy between functional hypothalamic amenorrhea and congenital hypogonadotropic hypogonadism

ObjectiveTo compare the ongoing pregnancy rate per initiated cycle between patients with functional hypothalamic amenorrhea and patients with congenital hypogonadotropic hypogonadism treated with pulsatile GnRH administration. DesignRetrospective monocentric cohort study conducted at the University Hospital of Lille from 2004 to 2022. Patient(s)141 patients diagnosed with central supra-pituitary amenorrhea during infertility evaluation and subsequently treated with pulsatile GnRH therapy. 111 and 30 patients were diagnosed with functional hypothalamic amenorrhea or congenital hypogonadotropic hypogonadism, respectively. Exposure(s)Pulsatile GnRH administration Main outcome measure(s)Ongoing pregnancy rate per initiated cycle. Result(s)Ongoing pregnancy rates per initiated cycle were comparable between groups: 21.5% in the functional hypothalamic amenorrhea group versus 22% in the congenital hypogonadotropic hypogonadism group; p=0.537. Comparison of baseline characteristics showed a more pronounced FSH deficiency in patients with congenital hypogonadotropic hypogonadism than in those with functional hypothalamic amenorrhea: 2.55 [0.6 - 4.92] versus 4.80 [3.90 - 5.70] UI/L; p<0.001. Within the congenital hypogonadotropic hypogonadism group, basal FSH level was positively associated with the occurrence of ongoing pregnancies (OR= 1.57; CI95%: 1.11;2.22; p=0.010). In the congenital hypogonadotropic hypogonadism group the duration of treatment was higher than in the functional hypothalamic amenorrhea group: 23.59 (±8.02) versus 18.16 (±7.66) days, p<0.001. ConclusionBaseline FSH is lower in patients with congenital hypogonadotropic hypogonadism than in patients with functional hypothalamic amenorrhea. The lower the FSH, the lower the chance of pregnancy in patients with congenital hypogonadotropic hypogonadism. These patients also require more days of GnRH administration. However, the rate of ongoing pregnancies is comparable between the two groups.

United Kingdom data collection of semen quality in transgender adolescent females seeking fertility preservation

ObjectiveIncreasing numbers of adolescents with gender dysphoria start gonadotropin-releasing hormone agonists to halt puberty, minimising psychological distress. The uncertainty of long-term effects of this medication, and the subsequent likelihood of accessing gender affirming hormone treatment, highlights the importance of fertility preservation prior to starting hormone treatment. We investigated the take up, hormonal profile and sperm quality in adolescents undergoing fertility preservation via cryopreservation by masturbation or surgical sperm retrieval, prior to starting hormonal therapy. DesignData was prospectively maintained from a tertiary UK-based hospital. 122 people under 19 years, mean age 15.2 +/- 1.7 years, referred by gender clinics and GPs, were included in this cohort study. SubjectsParticipants were counselled for fertility preservation, and serum testosterone, follicle stimulating hormone, and luteinizing hormone levels were recorded prior to providing semen samples. InterventionMasturbation semen samples were classified as normal (>15mil/ml), oligozoospermia (1mil-15mil/ml), cryptozoospermia (<1mil/ml) or azoospermia. If the sample was insufficient or the person was unwilling to masturbate, surgical sperm retrieval was offered in a stepwise manner using electroejaculation, TESE +/- mTESE. Main Outcome measurementsQuality of semen produced by participants, via masturbation or surgical sperm retrieval, was analysed to determine if it was good enough to cryopreserve for future fertility use. Results23/122 (19%) participants declined sample storage.In the masturbation group (average age 16.3), 78 people produced 106 samples. 86/106 were stored - 43.7% were normospermic, 35.9% oligozoospermic, 8.7% cryptozoospermic, 11.7% azoospermic. Overall, semen parameters varied but were generally abnormal, illustrated by only 43.7% of the masturbation samples produced being normospermic.For surgical sperm retrieval subjects (average age 15.2), electroejaculation was successful in 4/21 people, while the rest proceeded with TESE/mTESE. Encouragingly, 16/21 subjects had an average of 5 vials stored, and all participants had a testosterone level >8nmol/l. Semen parameters in this sub-cohort were poor but possibly adequate for intracytoplasmic sperm injection. ConclusionsIn this large database of transgender girls referred for fertility preservation in the UK, fertility preservation is possible, even with those unwilling to masturbate. Long-term data is required to check the health of these gametes, observing live birth rates using these preserved gametes.

Impact of polyamine supplementation on GnRH expression, folliculogenesis, and puberty onset in young mice

BackgroundThe hypothalamic-pituitary-gonadal (HPG) axis is pivotal in regulating reproductive functions, with gonadotropin-releasing hormone (GnRH) acting as a central regulator. Recently, polyamines have been shown to regulate the HPG axis, including GnRH expression and ovarian biology in old and adult rodents. The present study firstly highlights the age-specific variation in the polyamine and their corresponding biosynthetic enzymes in the ovary during aging, and further, the study focuses on the effect of polyamines, putrescine, and agmatine, in young female mice. Method and resultImmunofluorescence analysis revealed age-related differences in the expression of ornithine decarboxylase 1 (ODC1), spermine (SPM), and spermidine (SPD) in the ovaries, with adult mice exhibiting significantly higher expression levels compared to young and old mice. Likewise, qPCR analysis showed the mRNA levels of Odc1, Spermidine synthase (Srm), and Spermine synthase (Sms) show a significant increase in adult ovaries, which is then followed by a significant decline in old age. Histological examination demonstrated morphological alterations in the ovaries with age, including decreased follicle numbers and increased stromal cells in old mice. Furthermore, treatment with putrescine, a polyamine, in young mice resulted in larger ovaries and increased follicle numbers compared to controls. Additionally, serum levels of gonadotropin-releasing hormone (GnRH) and progesterone (P4) were measured, showing elevated levels in polyamine-treated mice. GnRH mRNA expression also increased significantly. Gene expression analysis revealed upregulation of genes associated with folliculogenesis such as Fshr, Bmp15, Gdf9, Amh, Star, Hsdb3, and Plaur in the ovaries and onset of puberty such as Tac2, and Kiss1, and a decrease in Mkrn3 in the hypothalamus of polyamine-treated mice. ConclusionThis study investigates the effect of polyamines in young immature female mice, shedding light on their role in upregulating GnRH, and enhancing folliculogenesis. Overall, these findings suggest that polyamines play a crucial role in ovarian aging and HPG axis regulation, offering potential therapeutics to reinstate fertility in reproductively challenged individuals.