Luteinizing Hormone Receptor Expression Research Articles

Molecular characterization and stage-dependent gene expression of gonadotropin receptors in Pacific bluefin tuna, Thunnus orientalis, ovarian follicles

To understand the physiological mechanisms by which pituitary-derived gonadotropins (Gths), follicle-stimulating hormone (Fsh) and luteinizing hormone (Lh) regulate asynchronous oocyte development, we investigated the function and expression of Fsh and Lh receptors (Fshr and Lhr, respectively) in Pacific bluefin tuna (PBT, Thunnus orientalis). As a first, we cloned the full-length cDNAs encoding PBT Fshr and Lhr. Recombinant PBT Fsh and Lh single-chain proteins were produced in abundance using stable CHO-DG44 cell lines and were subsequently purified from the culture medium, culminating in their yields being 87.0 and 88.2%, respectively. An in vitro reporter assay using homologous recombinant Gths revealed that PBT Fshr and Lhr responded strongly to their corresponding ligands in a dose-dependent manner, with no cross-activation over a wide range of concentrations. Moreover, quantitative expression analysis of Fshr and Lhr at the follicle level showed that fshr gene expression was highly upregulated in the ovarian follicles through vitellogenesis, while lhr expression was significantly upregulated and peaked in fully vitellogenic ovarian follicles. These findings suggest that asynchronous-type oocyte development is primarily attributed to the differential function and expression of Gthrs, rather than the ligand, in PBT.

Primary unilateral macronodular adrenal hyperplasia with concomitant glucocorticoid and androgen excess and KDM1A inactivation.

Primary bilateral macronodular adrenal hyperplasia (PBMAH) is a rare cause of Cushing's syndrome. Individuals with PBMAH and glucose-dependent insulinotropic polypeptide (GIP)-dependent Cushing's syndrome due to ectopic expression of the GIP receptor (GIPR) typically harbor inactivating KDM1A sequence variants. Primary unilateral macronodular adrenal hyperplasia (PUMAH) with concomitant glucocorticoid and androgen excess has never been encountered or studied. We investigated a woman with a large, heterogeneous adrenal mass and severe adrenocorticotropic hormone-independent glucocorticoid and androgen excess, a biochemical presentation typically suggestive of adrenocortical carcinoma. The patient presented during pregnancy (22nd week of gestation) and reported an 18-month history of oligomenorrhea, hirsutism, and weight gain. We undertook an exploratory study with detailed histopathological and genetic analysis of the resected adrenal mass and leukocyte DNA collected from the patient and her parents. Histopathology revealed benign macronodular adrenal hyperplasia. Imaging showed a persistently normal contralateral adrenal gland. Whole-exome sequencing of 4 representative nodules detected KDM1A germline variants, benign NM_001009999.3:c.136G > A:p.G46S, and likely pathogenic NM_001009999.3:exon6:c.865_866del:p.R289Dfs*7. Copy number variation analysis demonstrated an additional somatic loss of the KDM1A wild-type allele on chromosome 1p36.12 in all nodules. RNA sequencing of a representative nodule showed low/absent KDM1A expression and increased GIPR expression compared with 52 unilateral sporadic adenomas and 4 normal adrenal glands. Luteinizing hormone/chorionic gonadotropin receptor expression was normal. Sanger sequencing confirmed heterozygous KDM1A variants in both parents (father: p.R289Dfs*7 and mother: p.G46S) who showed no clinical features suggestive of glucocorticoid or androgen excess. We investigated the first PUMAH associated with severe Cushing's syndrome and concomitant androgen excess, suggesting pathogenic mechanisms involving KDM1A.

Luteinizing Hormone Receptor Mutation (LHRN316S) Causes Abnormal Follicular Development Revealed by Follicle Single-Cell Analysis and CRISPR/Cas9

Abnormal interaction between granulosa cells and oocytes causes disordered development of ovarian follicles. However, the interactions between oocytes and cumulus granulosa cells (CGs), oocytes and mural granulosa cells (MGs), and CGs and MGs remain to be fully explored. Using single-cell RNA-sequencing (scRNA-seq), we determined the transcriptional profiles of oocytes, CGs and MGs in antral follicles. Analysis of scRNA-seq data revealed that CGs may regulate follicular development through the BMP15-KITL-KIT-PI3K-ARF6 pathway with elevated expression of luteinizing hormone receptor (LHR). Because internalization of the LHR is regulated by Arf6, we constructed LHRN316S mice by CRISPR/Cas9 to further explore mechanisms of follicular development and novel treatment strategies for female infertility. Ovaries of LHRN316S mice exhibited reduced numbers of corpora lutea and ovulation. The LHRN316S mice had a reduced rate of oocyte maturation in vitro and decreased serum progesterone levels. Mating LHRN316S female mice with ICR wild type male mice revealed that the infertility rate of LHRN316S mice was 21.4% (3/14). Litter sizes from LHRN316S mice were smaller than those from control wild type female mice. The oocytes from LHRN316S mice had an increased rate of maturation in vitro after progesterone administration in vitro. Furthermore, progesterone treated LHRN316S mice produced offspring numbers per litter equivalent to WT mice. These findings provide key insights into cellular interactions in ovarian follicles and provide important clues for infertility treatment.Graphical

Functional characterization of follicle-stimulating hormone and luteinizing hormone receptors in cloudy catshark, Scyliorhinus torazame

The follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) in cloudy catshark were cloned, and recombinant FSHR and LHR were expressed for characterization. Ventral lobe extract (VLE) from the pituitary contains homologous FSH and LH, and it stimulated the cAMP signaling of FSHR and LHR dose-dependently. Two transcript variants of LHR (LHR-L with exon 10 and LHR-S without) were identified, and LHR-S was the dominant form with higher basal cAMP activity without VLE stimulation. Among various developmental stages of follicles, FSHR expression was mainly associated with the pre-vitellogenic and early white follicles. When follicles were recruited into vitellogenesis, the expression of FSHR decreased while of LHR was upregulated reciprocally, suggesting that LHR may also be responsible for the control of vitellogenesis in chondrichthyans. The expression of LHR-L was upregulated among maturing follicles before ovulation, indicating LHR-L could have a specific role in receiving the LH surge signal for final maturation. Plasma LH-like activity was transiently increased prior to the progesterone (P4)-surge and testosterone-drop at the beginning of P4-phase, supporting a pituitary control of follicle-maturation via LH signaling in chondrichthyans. The expression of follicular LHR was downregulated during the P4-phase when LH-like activity was high, indicating that the LH-dependent downregulation of LHR is conserved in chondrichthyans as it is in other vertebrate lineages. (213 words)

Endothelin-3 Suppresses Luteinizing Hormone Receptor Expression by Regulating the cAMP-PKA Pathway in Hen Granulosa Cells.

Previous research identified the expression of EDN3 in granulosa cells of preovulatory follicles in chickens. Notably, the expression level of EDN3 in Silky Fowl with low egg-laying performance was significantly higher than that in high-yield laying breed White Leghorn. Given the crucial role of granulosa cells in follicular development and maturation, it is very important to study the effect of EDN3 on the biological function of granular cells. In this study, an EDN3 overexpression plasmid was constructed and transfected into granular cells. The viability of these cells was detected using quantiative (qPCR), Cell Counting Kit-8 (CCK8), and 5-Ethynyl-2'-deoxyuridine (EdU) assays. Gonadal hormone synthesis was detected using enzyme-linked immunosorbent assay (ELISA) techniques. Finally, transcriptome sequencing was employed to identify differentially expressed genes. Result showed thatoverexpression of EDN3 was observed to promote cell viability. In addition, it significantly inhibits the expressions of LHR and cAMP-PKA signaling pathways. Cell transcriptome sequencing data displayed that EDN3 can upregulate energy metabolism and immune-related signaling pathways, whereas follicle maturation and the GnRH signaling pathway were downregulated. In conclusion, this study demonstrates that EDN3 can enhance granulosa cell viability and inhibit the expression of LHCGR, a process likely mediated through the cAMP-PKA signaling pathway. However, further evidence is required to substantiate the regulatory relationship between EDN3 and the cAMP-PKA signaling pathway.

P-678 Cabergoline has inhibitory effects on FSH-induced cell differentiation and estrogen secretion in a primary culture system of rat ovarian granulosa cells

Abstract Study question How does cabergoline have effects on cell differentiation and hormone secretion induced by FSH stimulation in ovarian granulosa cells? Summary answer Cabergoline suppresses LH receptor expression and Estradiol (E2) secretion in primary cultures of rat ovarian granulosa cells by inhibiting cAMP production induced by FSH stimulation. What is known already Cabergoline is a dopamine receptor 2 agonist that has been used to treat hyperprolactinemia and, more recently, to prevent ovarian hyperstimulation syndrome. Although it has been previously reported that cabergoline suppresses E2 and Progesterone secretion induced by FSH stimulation in a primary culture system of rat ovarian granulosa cells, but the effect on LH receptor expression has not been investigated. It has also been reported that the activation of dopamine receptor 2 suppresses VEGF secretion and reduces the incidence of early-onset OHSS by inhibiting the VEGF/VEGFR2 pathway in research using human luteinized granulosa cells. Study design, size, duration We used a primary culture system of ovarian granulosa cells obtained from immature female rats treated with diethylstilbestrol to examine the effect of cabergoline addition on the changes in ovarian granulosa cells induced by FSH stimulation. Participants/materials, setting, methods FSH and cabergoline were added alone or co-added to a primary culture system of rat ovarian granulosa cells, and the changes induced by them were measured and compared. (1) mRNA expression of Lhcgr, Cyp19a1, and Fshr by RT-qPCR (2) E2 concentration in the culture medium (3) Measurement of hCG binding on the cell surface (4) cAMP concentration Main results and the role of chance Co-addition of cabergoline suppressed each of the changes induced by FSH stimulation as follows. (1) The mRNA expression levels of Lhcgr, Cyp19a1, and Fshr decreased in a concentration-dependent manner (0.01-10 µM) of co-added cabergoline compared to FSH alone. In the 10 µM of co-added cabergoline group, they decreased to 14%, 9%, and 49% of FSH alone, respectively. (2) E2 concentration in the culture media also decreased in a concentration-dependent manner (1-10 µM) of co-added cabergoline compared to FSH alone. In the 10 µM of co-added cabergoline group, it decreased to 49% of FSH alone. (3) The amount of hCG binding on the cell surface also decreased in a concentration-dependent manner (0.1-10 µM) of co-added cabergoline compared to FSH alone. In the 10 µM of co-added cabergoline group, it decreased to 7% of FSH alone. (4) FSH-stimulated cAMP production decreased in a concentration-dependent manner (0.01-1µM) of co-added cabergoline compared to FSH alone. In the 1µM of co-added cabergoline group, it decreased to 50% of FSH alone. These results suggest that cabergoline suppresses LH receptor and aromatase expression and E2 production by inhibiting cAMP production induced by FSH stimulation. Limitations, reasons for caution Since this is an in vitro experiment using a rat primary culture system, the results of this research cannot be considered directly applicable to humans. Wider implications of the findings Our findings imply that cabergoline administration during the follicular phase may inhibit ovarian granulosa cell differentiation and estrogen secretion. In women taking relatively high doses of cabergoline, attention may need to be paid regarding the effects of cabergoline on follicular development and estrogen secretion. Trial registration number not applicable

O-299 Exposure of antral follicles to progestins during stimulation does not cause molecular perturbations in gonadotropin-responsiveness and steroidogenic function of granulosa cells in progestin-primed IVF cycles

Abstract Study question Does progestin exposure cause any molecular perturbations in the steroidogenic features and gonadotropin responsiveness of the granulosa cells in progestin-primed ovarian stimulation (PPOS) cycles? Summary answer No. PPOS cycles are identical to antagonist cycles for gonadotropin receptor expression, response to gonadotropins, steroidogenic function at molecular level in normal responding IVF patients. What is known already PPOS is commonly used in IVF cycles as an alternative to antagonist cycles. Although accumulating evidence from clinical studies did not indicate any particular differences between these two types of stimulation protocol for IVF cycle characteristics, it is still unknown if exposure of antral follicle cohorts to synthetic progesterone derivatives during ovarian stimulation causes any subtle molecular aberrations in PPOS cycles in terms of steroidogenesis and gonadotropin responsiveness. To address this issue, detailed molecular analyses were conducted in the luteinized mural granulosa cells (GCs) obtained from the normal responding patients undergoing PPOS vs. antagonist IVF cycles. Study design, size, duration A translational research study in IVF patients. Participants/materials, setting, methods 55 normal responding IVF patients underwent ovarian stimulation either with PPOS using medroxy progesterone acetate (5mg twice daily) or, with GnRH antagonist cetrorelix acetate were included in the study. Recombinant forms of FSH and hCG were used for ovarian stimulation and ovulation trigger, respectively. Luteinized mural granulosa cells obtained during oocyte retrieval procedure were used for the experiments. Cell culture, quantitative real-time PCR, immunoblotting, confocal time-lapse live cell imaging and hormone assays were used. Main results and the role of chance Demographic and IVF characteristics of the patients undergoing ovarian stimulation with PPOS vs. GnRH antagonist were similar including ovarian-response, mature oocyte yield and fertilization rates. Molecular analyses revealed that the expression of the enzymes involved in sex-steroid synthesis (StAR, aromatase, 3B-HSD, 17B-HSD) and uptake/storage/utilization of cholesterol (LDL receptor, Hormone-sensitive lipase, hydroxy-methyl glutaryl Co-enzyme-A reductase and Sterol O-acyltransferase1) in the GCs of the PPOS cycles were comparable to the antagonist IVF cycles. Both cycles were also similar for the expression of FSH and LH receptors at transcriptional and translational level. Basal and hCG-induced increases in 3B-HSD expression and P4 production, and basal and FSH-induced increases in aromatase expression and E2 output of the GCs of the PPOS patients did not show any meaningful differences from the antagonist cycles. Similarly, basal and hCG-induced up-regulation in the LDL receptor expression and cholesterol uptake rate did not differ between the groups. Confocal imaging also revealed similar patterns of expression for the steroidogenic enzymes and their co-localization with mitochondria. Lastly, the expression of the other genes regulating cumulus expansion, ovulation and luteal function (Relaxin, ADAMTS-1 and EGF-like growth factor amphiregulin (AREG)) in the GCs of the PPOS cycles were comparable to the antagonist cycles. Limitations, reasons for caution Caution should be exercised when interpreting our data, which was produced in normal responders. It is unclear if the molecular parameters assessed here vary according to infertility etiologies, ovarian response type, mode of trigger and any other underlying ovarian pathology or systemic diseases that are concomitantly present. Wider implications of the findings This study provides reassuring molecular evidence that exposure of antral cohorts to progestins follicular growth phase does not appear to have any detrimental effect on their steroidogenic, ovulatory and luteal functions, suggesting that PPOS IVF cycles are not different from traditional antagonist cycles. Trial registration number not applicable

Camel milk or silymarin could improve the negative effects that experimentally produced by aflatoxin B1 on rat’s male reproductive system

BackgroundCamel milk and silymarin have many different beneficial effects on several animal species. Meanwhile, Aflatoxins are mycotoxins with extraordinary potency that pose major health risks to several animal species. Additionally, it has been documented that aflatoxins harm the reproductive systems of a variety of domestic animals. The present design aimed to investigate the impact of aflatoxin B1 (AFB1) on rat body weight and reproductive organs and the ameliorative effects of camel milk and silymarin through measured serum testosterone, testes pathology, and gene expression of tumor necrosis factor (TNF-α), luteinizing hormone receptor (LHR), and steroidogenic acute regulatory protein (StAR) in the testes. A total of sixty mature male Wister white rats, each weighing an average of 83.67 ± 0.21 g, were used. There were six groups created from the rats. Each division had ten rats. The groups were the control (without any treatment), CM (1 ml of camel milk/kg body weight orally), S (20 mg silymarin/kg b. wt. suspension, orally), A (1.4 mg aflatoxin/kg diet), ACM (aflatoxin plus camel milk), and AS (aflatoxin plus silymarin).ResultsThe results indicated the positive effects of camel milk and silymarin on growth, reproductive organs, and gene expression of TNF-α, LHR, and StAR with normal testicular architecture. Also, the negative effect of AFB1 on the rat’s body weight and reproductive organs, as indicated by low body weight and testosterone concentration, was confirmed by the results of histopathology and gene expression. However, these negative effects were ameliorated by the ingestion of camel milk and silymarin.ConclusionIn conclusion, camel milk and silymarin could mitigate the negative effect of AFB1 on rat body weight and reproductive organs.

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

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

Expression of luteinizing hormone receptor during development of bovine fetal ovary.

Steroids and gonadotrophins are essential for the regulation of late stages of preantral development and antral follicular development. Although the luteinizing hormone receptor (LHCGR) has been detected in the preantral follicles of rats, rabbits, and pigs, its expression, in bovine fetal ovary, has not been demonstrated. Based on this, we aimed to investigate the expression of the LHCGR and LHCGR mRNA binding protein (LRBP), as well as, to quantify bta-miR-222 (a regulatory microRNA of the LHCGR gene) during the development of bovine fetal ovary. In summary, LHCGR expression was observed in the preantral follicle in bovine fetal ovary, from oogonias to primordial, primary and secondary stages, and the mRNA abundance was lower on day 150 than day 60. However, the mRNA abundance of LRBP followed the opposite pattern. Similar to LRBP, the abundance of bta-miR-222 was higher on day 150 than day 60 or 90 of gestation. The LHCGR protein was detected in oogonia, primordial, primary, and secondary follicles. Moreover, both oocytes and granulosa cells showed positive immunostaining for LHCGR. In conclusion, we suggest the involvement of LHCGR/LRBP/bta-mir222 with mechanisms related to the development of preantral follicles in cattle.

Steroid profile and ovarian gene expression in Genyatremus luteus (Teleostei, Perciformes: Haemulidae) during sexual maturation

The aim of the present study was to assess histological features, sex steroid profile, and ovarian gene expression throughout the ovarian maturation of Genyatremus luteus in Brazilian Coastal Equatorial Amazon. Specimens were categorized into different gonadal maturation stages–immature (n = 7), maturing (n = 7), mature (n = 7), and spawned (n = 7)–based on histological features of ovarian follicles and on oocyte development. Plasma E2, 11-KT and 17α-OHP levels were measured through enzyme-linked immunosorbent assays. The gene expression of estrogen (er) and LH (lhr) receptors in the ovary was analyzed through real-time polymerase chain reaction. The highest plasma E2 concentration was found in mature specimens (P< 0.05). Plasma 17α-OHP concentrations have significantly increased from the immature to the final maturation stage (P< 0.05). Maturational reproductive stage did not have any effect on plasma 11-KT concentrations. Er expression in ovaries has significantly increased throughout ovarian maturation (P < 0.05), and it remained high at mature and spawned stages. Lhr expression showed similar trend throughout the maturation process, although its peak was observed at spawned stage (P< 0.05). In conclusion, the gene expression profile of er and lhr and plasma E2 and 17α-OHP concentrations are proportional to oocyte development; they play important role in regulating ovarian development and ovulation in G. luteus.

Molecular insights into the effects of tetrachlorobisphenol A on puberty initiation in Wistar rats

Tetrachlorobisphenol A (TCBPA) is the chlorinated derivative of bisphenol A (BPA). Several studies have found that BPA adversely affects the reproductive activity largely through binding to estrogen receptors and the critical period of BPA exposure advances the vaginal opening time in the female offspring via the kisspeptin/G protein-coupled receptor 54 (KGG) system. However, whether TCBPA can affect puberty initiation via KGG and the roles of estrogen receptors in this process remain unknown. Therefore, this study investigated the influence of TCBPA on the onset time of puberty in Wistar rats and the related molecular mechanisms by combing in vitro GT1–7 cells and molecular docking. In female Wistar rats, TCBPA at ≥100 mg/kg bw/day (49.2 μmol/L in rat body) markedly advanced vaginal opening time and increased serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and gonadotropin-releasing hormone (GnRH). It also increased the relative gene expression of LH receptor (LHR), GnRH1, and FSH receptor (FSHR) in hypothalamic-pituitary-gonadal (HPG) axis tissues. In GT1–7 cells, TCBPA increased genes and proteins associated with KGG pathway and activated the extracellular-regulated protein kinase 1/2 (Erk1/2) and phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) pathways via G protein-coupled estrogen membrane receptor 1 (GPER1) and estrogen receptor alpha (ERα). Docking analyses supported its interactions with GPER1 and ERα, and treatment with specific inhibitors of ERα- and GPER1-modulated PI3K/Akt and Erk1/2 signaling suppressed its effects. Taken together, TCBPA-induced advancement of puberty initiation in Wistar rats thus results primarily from increased LH, GnRH, and FSH secretion together with GnRH1, FSHR, and LHR upregulation driven by ERα- and GPER1-modulated Erk1/2 and PI3K/Akt signaling. Our results provide new molecular insights into the reproductive toxicity of EDCs.

Effects of Calcium, Available Phosphorus and Microbial Phytase on Ovarian FSHR and LHR Expression in Laying Hens

Folliculogenesis, steroidogenesis, ovulation, and vitellogenesis are regulated by the effect of follicle stimulating hormone (FSH) and luteinizing hormone (LH) in the hypothalamus-pituitary-ovary axis and these hormones act via follicle stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) in the ovary. Poultry ration and food additives are essential in the regulation of reproductive activity. Phytase is a supplement frequently added to laying hen diets to increase phosphorus (P) utilization. The aim of this study was to reveal the effects of a newly isolated microbial phytase together with different concentrations of calcium (Ca2+) and available phosphorus (AP) on ovarian FSHR and LHR expressions. For this purpose, 90 Lohmann LSL-White layers were first divided into three main diet groups (standard Ca2+ and AP, standard Ca2+ and low AP, low Ca2+ and AP) and then into three subgroups (no-phytase, commercial phytase, and microbial phytase). At the end of the experiment, all chickens were slaughtered and ovarian tissues were fixed in formalin. Routine avidin-biotin complex immunohistochemistry was performed using anti-FSHR and anti-LHR primary antibodies. Immunohistochemically, FSHR and LHR were expressed in granulosa/theca cells, oocytes, interstitial cells, and vitellus. While the expression intensity of the receptors increased in the microbial phytase-treated groups, the strongest expression was obtained in the granulosa/theca cells and oocytes in the standard Ca and low AP group. In conclusion, we suggest that the addition of newly isolated microbial phytase to diets of laying hens and feeding standard Ca and low AP may have positive effects on reproductive performance by increasing the FSHR and LHR expression in ovaries.

Steroidogenic Effect of Luteinizing Hormone Receptor Agonists and Metformin in Male Rats with Androgenic Deficiency Caused by Diet-Induced Obesity

In obese men, along with metabolic disorders and insulin resistance, testosterone levels are decreased and reproductive system functions are impaired. One of the ways to correct them may be the use of agonists of luteinizing hormone receptor (LHR) and antidiabetic drugs, but the mechanisms of their effect on the hypothalamic-pituitary-gonadal axis have not been studied enough. The aim of the work was to study the effects of long-term MF therapy (5 weeks, 120 mg/kg) and five-day treatment with LHR agonists, such as human chorionic gonadotropin (hCG, 20 IU/rat/day, s.c.) and allosteric agonist TP03 (15 mg/kg/day, i.p.), on the blood testosterone levels and the expression of testicular and pituitary genes in male rats with long-term diet-induced obesity (DIO). TP03 moderately stimulated testosterone production in male rats with DIO without having an inhibitory effect on LHR expression in the testes and only weakly reducing the expression of the LH β-subunit gene in the pituitary gland. After a single administration into DIO-rats, the steroidogenic effect of TP03 was comparable to that in the control group, but after a five-day administration, it was significantly inferior to it. In DIO-rats, the steroidogenic effect of hCG after a single administration was lower than that in the control, but comparable to that after a five-day administration of hCG, and significantly exceeded the corresponding effects of TP03. Unlike TP03, hCG significantly reduced LHR expression in the testes and more pronouncedly inhibited LH expression in the pituitary gland. MF treatment restored the androgenic status without significantly affecting the expression of steroidogenesis genes in the testes. There was no increase in the steroidogenic effects of both LHR agonists in the MF-treated groups. The results obtained indicate the prospects for the use of TP03 and hCG to stimulate testicular steroidogenesis and the effectiveness of MF therapy to normalize testosterone production in DIO, which can be used to correct reproductive disorders in obesity. At the same time, in DIO, the combined use of MF and LHR agonists seems to be inappropriate.

THE ROLE OF LUTEINIZING HORMONE (LH) RECEPTOR IN THE REGULATION OF OOCYTE MATURATION: A SYSTEMATIC LITERATURE REVIEW

The hormone luteinizing hormone (LH) is an important glycoprotein hormone that controls the activity of the gonadal organs, which in turn affects the physiology of the menstrual cycle. For LH to exert its effects, its specific receptor (LHR) must be expressed by cumulus cells. Objective: To determine the role of LH receptors (Luteinizing Hormone) in the regulation of human oocyte maturation processes Method:Systematic Literature Review (SLR). Data collection was conducted by documenting all articles based on predefined inclusion and exclusion criteria. A total of 10 national and international journal articles were retrieved from databases such as Google Scholar, PubMed, and Science Direct, using specific keywords related to the role of LH receptors and oocyte maturation. The literature search and study selection process followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Results:The highest expression of Luteinizing Hormone Receptor (LHR) observed in preovulatory follicles. Cumulus cell maturation, covering 100% of the oocytes, was 74%. FSHR and LHR mRNA expression levels increased with an increase in LH concentration in the in vitro maturation (IVM) medium. After 24 hours of IVM, there was a significant downregulation in the expression of LHR and FSHR.The mRNA and protein levels of FSHR and LHR in the cumulus-oocyte complex gradually decreased with increasing doses of FRBI in the IVM media compared to the control group. Majority of the cumulus cells from MII oocytes had RGS2/B2M gene expression of more than 50%. LH receptor expression in granulosa cells positively correlated with morphology, oocyte maturity, and fertility rate in the poor responder group. Granulosa cells from an agonist-triggered cycle with recombinant human chorionic gonadotropin (rhCG) for 24 hours were observed to increase viability, regulate mRNA expression of 3β-HSD, LH receptor, VEGF, and BCL-L2. More than 50% of the oocytes are matured after hCG injectionat an hCG concentration of 119.8 mIU/mL. Conclusion:LH needs receptor binding and expression for proper function, resulting in improved oocyte maturation with optimal LHR concentration which is 10 µg/mL LH. LHR expression is highest in preovulatory follicles. LHR expression increases during antral follicle growth. Supplementing media with hCG improves oocyte maturity with a 77 mIU/mL cutoff value. Supplementation with FRBI reduce LHR expression in COCs. The number of cumulus cells can also indicate the level of oocyte maturity, where cumulus cells covering 100% of the oocytes show the highest oocyte maturation.

Tissue-specific promoters regulate the transcription of cyp19a1 in the brain-pituitary-gonad axis of Japanese eel (Anguilla japonica)

Aromatase is a key enzyme that catalyzes the biosynthesis of estrogens. Previous study indicated that putative tissue-specific promoters of the one aromatase gene (cyp19a1) may drive the differential regulatory mechanisms of cyp19a1 expression in Anguilla japonica. In the present study, for elucidating the transcription characteristics and the function of putative tissue-specific promoters of cyp19a1 in the brain-pituitary-gonad (BPG) axis during vitellogenesis, we investigated the transcriptional regulation of cyp19a1 by 17β-estrogen (E2), testosterone (T), or human chorionic gonadotropin (HCG) in A. japonica. The expression of estrogen receptor (esra), androgen receptor (ara), or luteinizing hormone receptor (lhr) was up-regulated as cyp19a1 in response to E2, T, or HCG, respectively in the telencephalon, diencephalon, and pituitary. The expression of cyp19a1 was also upregulated in the ovary by HCG or T in a dose-dependent manner. Unlike in the brain and pituitary, the expression of esra and lhr, rather than ara, was upregulated by T in the ovary. Subsequently, four primary subtypes of 5′-untranslated terminal regions of cyp19a1 transcripts and the corresponding two 5′ flanking regions (promoter P.I and P.II) were identified. The P.II existed in all BPG axis tissues, whereas the P.I with strong transcriptional activity was brain- and pituitary-specific. Furthermore, the transcriptional activity of promoters, the core promoter region, and the three putative hormone receptor response elements were validated. The transcriptional activity did not change when the HEK291T cells co-transfected with P.II and ar vector were exposed to T. These results suggested that the expression of cyp19a1 was upregulated indirectly through esra and lhr rather than ara by T in the ovary, whereas the expression of cyp19a1 was upregulated directly through androgen receptor and the downstream androgen response element of tissue-specific P.I in the brain and pituitary. The results of the study reveal the regulatory mechanisms of estrogen biosynthesis and provide a reference for optimizing the technology of artificially induced maturation in eels.

Specific Signal Transduction of Constitutively Activating (D576G) and Inactivating (R476H) Mutants of Agonist-Stimulated Luteinizing Hormone Receptor in Eel.

We investigated the mechanism of signal transduction using inactivating (R476H) and activating (D576G) mutants of luteinizing hormone receptor (LHR) of eel at the conserved regions of intracellular loops II and III, respectively, naturally occurring in mammalian LHR. The expression of D576G and R476H mutants was approximately 58% and 59%, respectively, on the cell surface compared to those of eel LHR-wild type (wt). In eel LHR-wt, cAMP production increased upon agonist stimulation. Cells expressing eel LHR-D576G, a highly conserved aspartic acid residue, exhibited a 5.8-fold increase in basal cAMP response; however, the maximal cAMP response by high-agonist stimulation was approximately 0.62-fold. Mutation of a highly conserved arginine residue in the second intracellular loop of eel LHR (LHR-R476H) completely impaired the cAMP response. The rate of loss in cell-surface expression of eel LHR-wt and D576G mutant was similar to the agonist recombinant (rec)-eel LH after 30 min. However, the mutants presented rates of loss higher than eel LHR-wt did upon rec-eCG treatment. Therefore, the activating mutant constitutively induced cAMP signaling. The inactivating mutation resulted in the loss of LHR expression on the cell surface and no cAMP signaling. These data provide valuable information regarding the structure-function relationship of LHR-LH complexes.

Effect of peripheral neural stimulation with allopregnanolone on ovarian physiology.

Neuroactive steroids can rapidly regulate multiple physiological functions in the central and peripheral nervous systems. The aims of the present study were to determine whether allopregnanolone (ALLO), administered in low nanomolar and high micromolar concentrations, can: (i) induce changes in the ovarian progesterone (P4) and estradiol (E2) release; (ii) modify the ovarian mRNA expression of Hsd3b1 (3β-hydroxysteroid dehydrogenase, 3β-HSD)3β-, Akr1c3 (20α-hydroxysteroid dehydrogenase, 20α-HSD), and Akr1c14 (3α-hydroxy steroid oxidoreductase, 3α-HSOR)); and (iii) modulate the ovarian expression of progesterone receptors A and B, α and β estrogenic receptors, luteinizing hormone receptor (LHR) and follicle-stimulating hormone receptor (FSHR). To further characterize ALLO peripheral actions, the effects were evaluated using a superior mesenteric ganglion-ovarian nervous plexus-ovary (SMG-ONP-O) and a denervated ovary (DO) systems. ALLO SMG administration increased P4 concentration in the incubation liquid by decreasing ovarian 20α-HSD mRNA, and it also increased ovarian 3α-HSOR mRNA expression. In addition, ALLO neural peripheral modulation induced an increase in the expression of ovarian LHR, PRA, PRB, and ERα. Direct ALLO administration to the DO decreased E2 and increased P4 concentration in the incubation liquid. The mRNA expression of 3β-HSD decreased and 20α-HSD increased. Further, ALLO in the OD significantly changed ovarian FSHR and PRA expression. This is the first evidence of ALLO's direct effect on ovarian steroidogenesis. Our results provide important insights about how this neuroactive steroid interacts both with the PNS and the ovary, and these findings might help devise some of the pleiotropic effects of neuroactive steroids on female reproduction. Moreover, ALLO modulation of ovarian physiology might help uncover novel treatment approaches for reproductive diseases.

Seasonal Variation of Melatonin Concentration and mRNA Expression of Melatonin-Related Genes in Developing Ovarian Follicles of Mares Kept under Natural Photoperiods in the Southern Hemisphere.

This study investigated the seasonal variations in mRNA expression of FSH (Fshr), LH (Lhr) receptors, melatonin (Mt1 and Mt2) receptors, melatonin-synthetizing enzymes (Asmt and Aanat) and melatonin concentration in developing follicles from mares raised in natural photoperiods. For one year, ultrasonographic follicular aspiration procedures were performed monthly, and small (<20 mm), medium (20 to 35 mm) and large (>35 mm) follicles were recovered from five mares. One day before monthly sample collections, an exploratory ultrasonography conducted to record the number and the size of all follicles larger than 15 mm. The total number of large follicles were higher during the spring/summer (8.2 ± 1.9) than during autumn/winter (3.0 ± 0.5). Compared to autumn/winter seasons, there was an increase of Fshr and Aanat mRNA expressions in small, medium and large follicles, an increase of Lhr and Asmt mRNA expressions in medium and large follicles and an increase of Mt1 and Mt2 mRNA expressions in small and large follicles during spring/summer. The melatonin levels in follicular fluid were also higher during the spring/summer seasons. The present data show that melatonin locally upregulates the mRNA expression of Mt1 and Mt2 receptors and melatonin-forming enzymes in mare developing follicles during reproductive seasons.

Ethanol potentiates follicle-stimulating hormone action in ovarian granulosa cells.

There are many previous reports on the effects of ethanol on physiological function, including reports of elevated blood estrogen levels in women who drank alcohol. However, the mechanism of ethanol's effects on ovarian functions, such as follicle development and hormone secretion, has not been fully clarified. Therefore, in this study, we investigated the impacts of ethanol on these phenomena and their mechanisms using a primary culture system of rat ovarian granulosa cells (GCs). In the present experiment, groups were created in which follicle-stimulating hormone (FSH) or ethanol was added alone or FSH and ethanol were co-added, and mRNA and protein expression in each group was measured for luteinizing hormone receptor (LHR) and sex steroid hormone synthase, as well as for estradiol (E2) production, cAMP production, and FSH receptor (FSHR) internalization rate. The addition of FSH induced mRNA expression of LHR and aromatase, which led to membrane LHR expression and E2 production. The coexistence of ethanol enhanced all these responses. The action of FSH is exerted via cAMP, and the co-addition of ethanol enhanced this cAMP production. Ethanol alone did not induce cAMP production. The enhancing effect of ethanol was also observed for cAMP induced by cholera toxin. Ethanol had no significant effect on the internalization rate of FSHR. In conclusion, ethanol increased FSH-stimulated cAMP production by increasing the activity of adenylyl cyclase, which enhanced FSH actions in rat GCs. Alcohol is an exacerbating factor in several female hormone-related diseases, and the mechanism of ethanol-induced increase in estrogen secretion revealed in this study may be involved in the pathogenesis of these diseases.