LH Gene Research Articles

A novel agent for induced spawning using a combination of GnRH analog and an FDA-approved dopamine receptor antagonist

In certain fish species, endogenous dopamine has a significant inhibitory effect on LH release and spawning induced by externally applied GnRH. Preovulatory LH surge and spawning in these fish species are caused by the simultaneous release of GnRH and exclusion of the dopaminergic inhibition. To induce spawning, a potent dopamine D2 receptor (DRD2) antagonist and a GnRH analog are concomitantly applied to fish with solid dopaminergic inhibition. However, the currently used dopamine antagonists are not approved by the FDA for veterinary use. This project was conducted in order to find a novel FDA-approved dopamine antagonist that will be efficient in spawning induction in fish species and will not be lethal to the fish. First, we studied the inhibitory effect of the novel dopamine antagonist, azaperone, on tilapia DRD2, transiently expressed in COS-7 cell line. Azaperone was more effective than metoclopramide in antagonizing the effect of quinpirole on taDRD2 both in terms of EC50 and maximal response. Next, we tested the ability of the combination of the dopamine antagonist and sGnRHa on GTH secretion, in adult tilapia. The novel dopamine antagonist significantly increased the GnRH-stimulated LH release in vivo, on both LH release and gene expression. We next aimed to test the novel combination in carp. The combination of the novel dopamine antagonist together with GnRHa, increased the release of estradiol and LH, in a dose-dependent manner. A higher hatching rate and spawning efficiency were observed than in the positive control that contained metoclopramide as a dopamine antagonist.

Identification and functional characterization of gonadotropin -releasing hormone in pompano (Trachinotus ovatus)

Gonadotropin-releasing hormone (GnRH) is an important neuropeptide in the reproductive system. Although GnRH analogues have been used to artificially spawn pompano (Trachinotus sp.), the native forms of GnRH have not been described in this species. In this study three GnRH subtypes [sea bream GnRH (sbGnRH), chicken GnRH-Ⅱ (cGnRH-Ⅱ) and salmon GnRH (sGnRH)] were identified in pompano (Trachinotus ovatus). cgnrh-Ⅱ and sgnrh were mainly expressed in the brain of male and female fish, showing a tissue-specific expression pattern, while sbgnrh was expressed at different transcriptional levels in all tested tissues. In vivo injection experiment showed that sbGnRH significantly increased fsh and lh genes expression in a dose-dependent manner, but a high concentration of sbGnRH could desensitize the expression of lh. High concentrations of cGnRH-Ⅱ and sGnRH could induce the expression of fsh and lh. In addition, the results of in vitro incubation experiments showed that the high concentration of sbGnRH peptide could induce the expression of fsh and lh, while cGnRH-Ⅱ and sGnRH peptides could only induce the expression of fsh. 17β-estradiol (E2) and 17α-methyltestosterone (MT) significantly inhibited sbgnrh mRNA expression in a dose-dependent manner, but did not affect the expression of cgnrh-Ⅱ and sgnrh mRNA. sbGnRH is the main GnRH subtype in pompano. E2 and MT can play a negative role in the regulation of sbgnrh. This study provides a theoretical basis for the reproductive endocrinology of pompano.

Identification, functional characterization, and estrogen regulation on gonadotropin-releasing hormone in the spotted scat, Scatophagus argus.

Gonadotropin-releasing hormone (GnRH) is a key neuropeptide of the reproductive system. However, little is known about the role of GnRH in the spotted scat (Scatophagus argus). Here, three GnRH subtypes (cGnRH-II, sGnRH, and sbGnRH) were identified in the spotted scat. cGnRH-II and sGnRH were only expressed in the brains and gonads of both male and female fish, exhibiting a tissue-specific expression pattern, while sbGnRH was expressed at different transcription levels in all examined tissues. During ovarian maturation, hypothalamus-associated sbGnRH was upregulated, while the expression of sGnRH was variable and cGnRH-II first increased and then decreased. In vivo experiments showed that sbGnRH significantly promoted the expression of fsh and lh genes in a dose-dependent manner and exhibited a desensitization effect on lh expression at high concentrations. For sGnRH and cGnRH-II, only high concentrations could induce fsh and lh expression. Furthermore, treatment with highly concentrated sbGnRH peptide also induced fsh and lh expression, whereas the sGnRH and cGnRH-II peptides only induced fsh expression in vitro. 17β-Estradiol (E2) significantly inhibited the expression of sbGnRH mRNA in a dose-dependent manner and did not impact sGnRH and cGnRH-II mRNA levels in vivo or in vitro. The inhibitory effect of E2 on sbGnRH expression was attenuated by the estrogen receptor (ER) broad-spectrum antagonist (fulvestrant) and the ERα-specific antagonist (methyl-piperidinopyrazole), respectively, implying that the feedback regulation on sbGnRH is mediated via ERα. This study provides a theoretical basis for the reproductive endocrinology of the spotted scat by studying GnRH.

Identification and expression of gonadotrophin hormones in gouramy (Osphronemous gouramy, Lacepède, 1801) under photoperiod manipulations

Abstract. Prayogo NA, Siregar AS, Sukardi P, Bessho Y. 2020. Identification and expression of gonadotrophin hormones in gouramy (Osphronemoous gouramy, Lacepède, 1801) under photoperiod manipulations. Biodiversitas 21: 1365-1372. The environment influences fish reproduction. One of the influential environmental factors is photoperiod that regulates the production of hormones for gonad growth and development, gametogenesis, then the reproductive cycle. This research was conducted to determine the effect of photoperiod on the reproductive performance of gouramy with different photoperiod treatments. The design of this study was four photoperiod treatments consisting of 14L: 10D, 16L: 8D and 18L: 6D and controls. Fish samples were divided into 4 aquariums consisting of nine fish and repetition was conducted on each. Fish were kept under photoperiod treatment for 16 weeks. The observed variable was pituitary activity. Pituitary activity was evaluated by measuring the expression of FSH and LH genes using Real Time PCR. The results showed that gouramy had FSH and LH genes with 483 bp and 506 bp. FSH and LH gene expression increased with long photoperiod exposure (P <0.05). These findings indicate that photoperiods regulate the reproduction of gouramy through the HPG axis and control the production of the hormone Gonadotropin.

Profile of follicle-stimulating hormone and polymorphism of follicle-stimulating hormone receptor in Madrasin cattle with ovarian hypofunction.

Background and Aim:The follicle-stimulating hormone (FSH) gene is an essential regulator of fertility in livestock. This study aims to provide information on the genetic makeup of Madrasin cattle experiencing hypofunction by the FSH profile and FSH receptors (FSHR) polymorphism.Materials and Methods:Blood samples were collected from the Bangkalan regency in Indonesia. DNA was isolated and purified following the extraction protocol of polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism.Results:Our results showed that the FSH gene had a band length of 310 bp and produce two alleles (A and B) with restriction enzymes at 250 bp, 230 bp, and 145 bp. Furthermore, the FSHR gene had a band length of 303 bp and produced two homozygous genotypes: GG at bp 239 and CC at bp 188.Conclusion:Based on these differences, there was no change in allele frequency and genotype between Madura and Madrasin cattle due to crossbreeding with Limousin cattle. Thus, further detailed investigations of Madrasin cattle are required to elucidate the profile of the LH and LHR genes.

Effects of 17á-ethinylestradiol-based contraceptives on ovarian tissue using histopathological examination and FSH, LH, CYP1A, and CYP3A expressions using qRT-PCR in the ovaries and brain tissues of common carp (Cyprinus carpio L.)

In this study, the main aim was to identify the effects of exposure to 17á-ethinylestradiol-based contraceptives on the ovaries and brain tissues of common carp. For this purpose, histopathological changes were evaluated in ovaries after 21 days of contraceptive exposure. In addition, the expression levels of the CYP1A, CYP3A, FSH, and LH genes were measured in contraceptive-exposed brain tissue and ovaries respectively, using qRT-PCR (p less than 0.05, p less than 0.01, and p less than 0.001, respectively). No histopathological lesions, including inflammation, degeneration, or necrosis in the evaluated ovarian tissue of common carp were found after both high and low levels of exposure to contraceptives. Therefore, it is concluded that these contraceptives were highly dangerous to the reproduction system of common carp; the accumulation of contraceptive waste in the water supply could adversely affect and threat the common carp population. This may indirectly also affect other animals.

Molecular Detection of Follicle Stimulating Hormone Receptor Polymorphisms and Luteinizing Hormone Gene Variations in Primary and Secondary Iraqi Infertile Women

The current study aimed to determine the role of hormonal disturbances in infertility, moreover assessing variations at the molecular level that could affect this disease. The study examined 90 blood samples, 30 patients with primary infertility, 30 patients with secondary infertility and 30 healthy women as control. FSH and LH were measured using Electrochemiluminescence assay. DNA was isolated for molecular detection of polymorphisms at the nucleotide level (rs6166 and rs28928870) in FSHR gene using ASO PCR technique and identification mutations in LH gene using PCR technique followed by sequencing. The results showed no significant differences in FSH levels (6.95±4.55 mIU/ml, 5.48±4.64 mIU/ml and 5.52±3.07 mIU/ml) between control, primary and secondary respectively, while LH showed significant differences between primary and secondary groups (14.23±12.17 mIU/ml and 8.54±5.62 mIU/ml) respectively. A significant positive correlation was found between FSH and LH. The molecular study showed different polymorphisms at different positions in LH gene detected by sequencing. Regarding FSHR polymorphisms our results showed that the OR (95% CI) for AA and AG genotypes of Asn680Ser polymorphism (rs6166) was 3.32 (0.14-78-49) and 1.00 (0.06-15.99) respectively for primary infertility. Moreover, the OR (95% CI) for AA and AG of this polymorphism was 1.00 (0.07-17.59) and 3.0 (0.13-70.59) respectively for secondary infertility. While regarding Thr449Ile (rs28928870) only the wild type was detected in the studied group. In conclusion, AG genotype ofAsn680Ser is more prevalent in the Iraqi studied women. Furthermore, A allele is a risk factor for the disease as the (OR: 1.49 95% CI: 0.44-5.03) for the primary group and (OR: 1.22 95% CI: 0.35-4.23) for secondary group.

Histopathological effects, responses of oxidative stress, inflammation, apoptosis biomarkers and alteration of gene expressions related to apoptosis, oxidative stress, and reproductive system in chlorpyrifos-exposed common carp (Cyprinus carpio L.)

In this study, we aimed to identify the toxic effects of chlorpyrifos exposure on the tissues of common carp. For this purpose, we evaluated histopathological changes in the brain, gills, liver, kidney, testis, and ovaries after 21 days of chlorpyrifos exposure. Activation of 8-OHdG, cleaved caspase-3, and iNOS were assesed by immunofluorescence assay in chlorpyrifos-exposed brain and liver tissue. Additionally, we measured the expression levels of caspase-3, caspase-8, iNOS, MT1, CYP1A, and CYP3A genes in chlorpyrifos-exposed brain tissue, as well as the expression levels of FSH and LH genes in chlorpyrifos-exposed ovaries, using qRT-PCR. We observed severe histopathological lesions, including inflammation, degeneration, necrosis, and hemorrhage, in the evaluated tissues of common carp after both high and low levels of exposure to chlorpyrifos. We detected strong and diffuse signs of immunofluorescence reaction for 8-OHdG, iNOS, and cleaved caspase-3 in the chlorpyrifos-exposed brain and liver tissues. Furthermore, we found that chlorpyrifos exposure significantly upregulated the expressions of caspase-3, caspase-8, iNOS, and MT1, and also moderately upregulated CYP1A and CYP3A in the brain tissue of exposed carp. We also noted downregulation of FSH and LH gene expressions in chlorpyrifos-exposed ovary tissues. Based on our results, chlorpyrifos toxication caused crucial histopathological lesions in vital organs, induced oxidative stress, inflammation, and apoptosis in liver and brain tissues, and triggered reproductive sterility in common carp. Therefore, we can propose that chlorpyrifos toxication is highly dangerous to the health of common carp. Moreover, chlorpyrifos pollution in the water could threaten the common carp population. Use of chlorpyrifos should be restricted, and aquatic systems should be monitored for chlorpyrifos pollution.

H2A.Z controls the stability and mobility of nucleosomes to regulate expression of the LH genes.

The structure and dynamics of promoter chromatin have a profound effect on the expression levels of genes. Yet, the contribution of DNA sequence, histone post-translational modifications, histone variant usage and other factors in shaping the architecture of chromatin, and the mechanisms by which this architecture modulates expression of specific genes are not yet completely understood. Here we use optical tweezers to study the roles that DNA sequence and the histone variant H2A.Z have in shaping the chromatin landscape at the promoters of two model genes, Cga and Lhb. Guided by MNase mapping of the promoters of these genes, we reconstitute nucleosomes that mimic those located near the transcriptional start site and immediately downstream (+1), and measure the forces required to disrupt these nucleosomes, and their mobility along the DNA sequence. Our results indicate that these genes are basally regulated by two distinct strategies, making use of H2A.Z to modulate separate phases of transcription, and highlight how DNA sequence, alternative histone variants and remodelling machinery act synergistically to modulate gene expression.

Myricitrin and bioactive extract of Albizia amara leaves: DNA protection and modulation of fertility and antioxidant-related genes expression

Context: Albizia species are reported to exhibit many biological activities including antiovulatory properties in female rats and antispermatogenic and antiandrogenic activities in male rats.Objective: The present study investigates the flavonoids of Albizia amara (Roxb.) B. Boivin (Fabaceae) leaves and evaluates their activity on gene expression of fertility and antioxidant glutathione-S-transferase-related genes of treated female mice in addition to their effect on DNA damage.Materials and methods: Plant materials were extracted by using 70% methanol for 48 h, the extract was chromatographed on a polyamide 6S column, each isolated compound was purified by using Sephadex LH-20 column; its structure was elucidated by chemical and spectral methods. Both the leaves extract and myricitrin (200, 30 mg/kg bw/d, respectively) were assayed for their effect on DNA damage in female mice after four weeks treatment using Comet assay. Their modulatory activity on gene expression of fertility (aromatase CYP19 and luteinizing hormone LH) and antioxidant glutathione-S-transferase (GST)-related genes of treated female mice were investigated by real-time PCR (qPCR).Results: Quercetin-3-O-gentiobioside, myricitrin, quercetin-3-O-α-rhamnopyranoside, myricetin, quercetin and kaempferol were isolated and identified from the studied taxa. Myricitrin and the extract induced low rate of DNA damage (4.8% and 5%, respectively), compared with the untreated control (4.2%) and significantly down-regulated the expression of CYP19 and LH genes and up-regulated GST gene.Discussion and conclusion: Our results highlight the potential effect of the leaves extract of Albizia amara and myricitrin as fertility-regulating phytoconstituents with ability to protect DNA from damage and cells from oxidative stress.

Force Spectroscopy of Nucleosomes at the Promoters of the Lh Genes Reveals two Distinct Strategies for their Regulation

Luteinizing hormone (LH) is a heterodimeric protein that regulates function of the gonads, and is composed of two subunits, which are encoded by two different genes: chorionic gonadotropin-a (Cga) and Lhs. A sequence-based algorithm designed to predict nucleosome positions on DNA suggests that the promoters of both genes, and in particular the binding regions for important transcription factors, are packed into nucleosomes. Since gene expression requires that the promoter be accessible to the cellular transcription machinery, we hypothesized that nucleosome positioning regulates basal expression of these genes. We are performing single-molecule force spectroscopy with optical tweezers, complemented by MNase mapping, to probe the architecture of chromatin on both gene promoters. In gonadotrope cells, the promoter of Lhs is occupied by a nucleosome containing the variant H2A.Z, while the Cga promoter appears nucleosome-depleted. Optical tweezers experiments show that a nucleosome reconstituted on the Cga promoter is weaker, and poorly localized, as compared to the one on the promoter of LHs. This may suggest that it is evicted, in vivo, by chromatin remodelers. In contrast, the first nucleosome downstream of the transcription start site contains H2A.Z in Cga but H2A in Lhs, and is well localized on both genes, although more weakly bound on the Lhs than the Cga gene. Hence, these two genes are apparently regulated by distinct strategies, tailored to obtain higher expression for Cga, which encodes a subunit shared also by other hormones, and lower for Lhs, which is unique to this hormone. Our results highlight how DNA sequence, the usage of alternative histone variants and, possibly, remodeling machinery act synergistically to modulate gene expression.

It Takes Two Gonadotropins to Tango in Zebrafish But With a Mixed Tune.

In vertebrates, reproduction is under the tight control of a third order neuroendocrine loop. This 3-tiered axis, consisting of the hypothalamus, anterior pituitary gland, and gonads, is known as the hypothalamus-pituitary-gonadal axis. At the center of this hypothalamus-pituitarygonadal axis, the anterior pituitary gland secretes 2 gonadotropins, namely FSH and LH. Both FSH and LH are heterodimeric glycoproteins, sharing a common -subunit and a hormone-specific -subunit (FSH or LH ). FSH acts via the FSH receptor (FSHR), a G protein-coupled receptor expressed exclusively on the granulosa cells in the ovary and Sertoli cells in the testis, to stimulate folliculogenesis in female and spermatogenesis in male. LH, on the other hand, works through the LH receptor (also known as luteinizing hormone/choriogonadotropin receptor: LHCGR), another GPCR expressed on the theca cells in the ovary and Leydig cells in the testis, to promote steroidogenesis (1). This dogma is described in endocrinology textbooks, and it is well supported by genetic studies using the mouse model and by genetic mutations occurring in human patients. For example, knockout of the FSH gene (Fshb) or the FSHR (Fshr) gene leads to the folliculogenesis arrest at the preantral stage, resulting in infertility in female mice. The Fshb and Fshr null male mice, however, are fertile, albeit with smaller testes and reduced fecundity (2–4, also see Figure 1). In comparison, knockout of either the Lh (Lhb) or the Lhcgr (Lhcgr) gene leads to infertility in both male and female in mice (5–7, also see Figure 1). In this issue of Endocrinology, Ge and coworkers (8) at the University of Macau and The Chinese University of Hong Kong reported some new and interesting results that shed new light on the functions of Fshr and Lhcgr in zebrafish (see Figure 1). These authors showed that 1) knockout of the zebrafish fshr gene had genderspecific effects. Although the fshr / male fish were fertile (albeit with delayed spermatogenesis), knockout of the fshr gene in female led to a complete failure of follicle activation in the ovary, and all the follicles were arrested at early primary growth stage. These phenotypes are similar to what has been reported in mammals, suggesting that Fshr-mediated signaling plays a conserved role in controlling folliculogenesis in mammals and fish. 2) Genetic ablation of Lhcgr had no effect on folliculogenesis in the female or spermatogenesis in the male. Both male and female lhcgr / fish were fertile (8). This agrees well with another genetic study in zebrafish (9). Based on these findings, one may conclude that the Lhcgr-mediated signaling is dispensable in zebrafish. However, Ge and coworkers (8) discovered that double knockout of the 2 receptors resulted in complete infertility in both male and female fish, suggesting that Lhcgr-mediated signaling is functional in the absence of Fhsr-mediated signaling. In a related study published earlier this year, Ge and coworkers explored the functions of Fsh and Lh proteins by genetic disruption of the zebrafish FSH (fshb) and/or LH (lhb) genes. They showed that both the male and female fshb / fish were fertile (although with delayed spermatogenesis or folliculogenesis) (10). Although the lhb / null male fish were fertile, the female fish were infertile. This female infertility is due to a failure in spawning because the lhb / null female fish showed normal ovary growth (10). This result indicates that zebrafish Lh is

Role of the serotonergic axis in the reproductive failure associated with aging broiler breeder roosters

Reproductive failure associated with aging is a well-known phenomenon. However, the mechanism by which this failure occurs in broiler breeder roosters is still unclear. A previous study conducted in our laboratory, comparing young and aging broiler breeder roosters, demonstrated an elevation in hypothalamic vasoactive intestinal peptide (VIP) and pituitary prolactin (PRL) gene expression accompanied by a deterioration of gonadal axis function. This resulted in a decrease in semen-quality variables as roosters aged. The objective of this study was to examine the involvement of the serotonergic axis in the age-associated reproductive failure in broiler breeder roosters. Cobb roosters aged 64 wk were divided into 3 groups (n = 20 each): parachlorophenylalanine (PCPA) administration, active immunization against chicken VIP, and controls. At 69 wk of age, each group was divided into 2 equal subgroups: 1 received ovine PRL and the other served as controls. Weekly semen volume, concentration and motility, and plasma testosterone, estradiol, and PRL concentrations were examined. At the end of the experiment, roosters were euthanized, testes were weighed, and hypothalamus and pituitary were removed to assay the expression of genes encoding hypothalamic GnRH-I, pituitary FSH, pituitary LH, hypothalamic VIP, and pituitary PRL. Both PCPA administration and active immunization against chicken VIP significantly increased testis weight, semen volume, sperm concentration, ejaculation grade, plasma testosterone level, and GnRH-I, FSH and LH gene expression compared with controls (P ≤ 0.05). In addition, a decrease in plasma estradiol and PRL concentrations and VIP and PRL gene expression was observed in PCPA- and VIP-immunized birds compared with controls (P ≤ 0.05). Administration of PRL in all groups decreased gonadal axis function and semen-quality variables (P ≤ 0.05). Collectively, these results suggest that the increasing expression levels of the serotonergic axis in aging broiler breeder roosters inhibit proper gonadal function and reproductive performance. This article establishes for the first time the inhibitory role of serotonin on reproduction in aging roosters.

Morphological and molecular characterisation of Twitcher mouse spermatogenesis: an update.

Spermatogenesis is a complex developmental program in which interactions between different cell types are finely regulated. Mouse models in which any of the sperm maturation steps are perturbed provide major insights into the molecular control of spermatogenesis. The Twitcher mouse is a model of Krabbe disease, characterised by the deficiency of galactosylceramidase, the enzyme that hydrolyses galactosylceramide and galactosylsphingosine. Galactosyl-alkyl-acyl-glycerol, a precursor of seminolipid, the most abundant glycolipid in spermatozoa, is also a substrate for galactosylceramidase. Altered sphingolipid metabolism has been suggested to be the cause of the morphological abnormalities reported previously in the spermatogenesis of Twitcher. However, given the frequency of infertility associated with neurological impairment, we hypothesised that an unbalanced hormonal profile could contribute to male infertility in this mutant. In order to clarify this issue, we investigated potential variations in the expression of hormones and hormone receptors involved in the regulation of spermatogenesis. Our data show that, in the brain of Twitcher mouse, gonadotrophin-releasing hormone (GnRH), LH and FSH gene expression is decreased, whereas expression of androgen receptor (AR) and inhibin ?A (INH?A) is increased. The changes in gene expression for the LH and FSH receptors and AR in the testes support the hypothesis that altered sphingolipid metabolism is not the only cause of Twitcher infertility.

GnRH evokes localized subplasmalemmal calcium signaling in gonadotropes.

The binding of GnRH to its receptor initiates signaling cascades in gonadotropes, which result in enhanced LH and FSH biosynthesis and secretion. This process is necessary for follicular maturation and ovulation. Calcium influx activates MAPKs, which lead to increased transcription of LH and FSH genes. Previous research suggests that two MAPK signaling pathways, ERK and jun-N-terminal kinase, are activated by either calcium influx through L-type calcium channels or by global calcium signals originating from intracellular stores, respectively. Here we continued this investigation to further elucidate molecular mechanisms transducing GnRH receptor stimulation to ERK activation. Although it is known that GnRH activation of ERK requires calcium influx through L-type calcium channels, direct evidence supporting an underlying local calcium signaling mechanism was lacking. Here we used a combination of electrophysiology and total internal reflection fluorescence microscopy to visualize discrete sites of calcium influx (calcium sparklets) in gonadotrope-derived αT3-1 cells in real time. GnRH increased localized calcium influx and promoted ERK activation. The L-type calcium channel agonist FPL 64176 enhanced calcium sparklets and ERK activation in a manner indistinguishable from GnRH. Conversely, the L-type calcium channel antagonist nicardipine inhibited not only localized calcium sparklets but also ERK activation in response to GnRH. GnRH-dependent stimulation of L-type calcium channels was found to require protein kinase C and a dynamic actin cytoskeleton. Taken together, we provide the first direct evidence for localized L-type calcium channel signaling in αT3-1 cells and demonstrate the utility of our approach for investigating signaling mechanisms and cellular organization in gonadotropes.

A social and Biological Approach for Postpartum Depression in Egypt

Summary Postpartum depression (PPD) is a major health problem that affects many women worldwide. In Egypt, PPD is neglected despite the expected high prevalence rate among women during the transition period after the Egyptian revolution. This research investigated the prevalence, risk factors, and interventions of postpartum depression in southern rural Egypt. Interviews were conducted with 57 participants recruited from public and private hospitals. Questionnaires and the Arabic version of the Edinburgh Postnatal Depression Scale were administered. The prevalence of PPD was found to be 73.7% and is associated with low income and age at childbirth. Most participants regarded screening mothers after childbirth for PPD as an effective way to detect and intervene in PPD; in comparison to, antidepressants that were regarded by most participants as ineffective. Furthermore, in an effort to assess the cultural-suitability of prescribing antidepressants for PPD in such communities, where high pregnancy rate is favored, we examined the biological influence of Sertraline, a widely prescribed antidepressant medication, on the FSH and LH gene expression and discussed its possible effects on fertility based on our results.

Novel pituitary actions of TAC3 gene products in fish model: receptor specificity and signal transduction for prolactin and somatolactin α regulation by neurokinin B (NKB) and NKB-related peptide in carp pituitary cells.

TAC3 is a member of tachykinins, and its gene product neurokinin B (NKB) has recently emerged as a key regulator for LH through modulation of kisspeptin/GnRH system within the hypothalamus. In fish models, TAC3 not only encodes NKB but also a novel tachykinin-like peptide called NKB-related peptide (NKBRP), and the pituitary actions of these TAC3 gene products are still unknown. Using grass carp as a model, the direct effects and postreceptor signaling for the 2 TAC3 products were examined at the pituitary level. Grass carp TAC3 was cloned and confirmed to encode NKB and NKBRP similar to that of other fish species. In carp pituitary cells, NKB and NKBRP treatment did not affect LH release and gene expression but up-regulated prolactin (PRL) and somatolactin (SL)α secretion, protein production, and transcript expression. The stimulation by these 2 TAC3 gene products on PRL and SLα release and mRNA levels were mediated by pituitary NK2 and NK3 receptors, respectively. Apparently, NKB- and NKBRP-induced SLα secretion and transcript expression were caused by adenylate cyclase/cAMP/protein kinase A, phospholipase C/inositol 1,4,5-triphosphate/protein kinase C and Ca(2+)/calmodulin/Ca(2+)/calmodulin-dependent protein kinase II activation. The signal transduction for the corresponding responses on PRL release and mRNA expression were also similar, except that the protein kinase C component was not involved. These findings suggest that the 2 TAC3 gene products do not play a role in LH regulation at the pituitary level in carp species but may serve as novel stimulators for PRL and SLα synthesis and secretion via overlapping postreceptor signaling mechanisms coupled to NK2 and NK3 receptors, respectively.

Editorial: Molecular Endocrinology Articles in the Spotlight for April 2013

We are pleased to feature the following articles in this month’s issue of Molecular Endocrinology. Interestingly, the 3 articles provide novel insights into various hypothalamic pathways that regulate important aspects of reproduction and metabolism. In “GnRH Pulse Frequency-Dependent Stimulation of FSH Transcription Is Mediated via Activation of PKA and CREB,” Thompson et al provide a mechanism of GnRH pulse frequency-dependent activation of FSH involving differential activation of protein kinase A (PKA) and subsequent differential levels of cAMP-responsive element-binding protein (CREB) phosphorylation. LH gene expression is unaffected by this pathway. Furthermore, GnRH preferentially stimulates CREB phosphorylation at slow pulse frequencies, whereas PKA (the main regulator of CREB phosphorylation in the murine LT2 gonadotrope cell model) activity increases to a greater extent at slow GnRH pulse frequencies, correlating with the increase in CREB phosphorylation. Because pulsatile GnRHregulatestheexpressionandsecretionofbothFSH and LH, this work identifies the intracellular mechanism downstream of GnRH receptor activation responsible for triggering the diverse reproductive consequences of the individual gonadotropins. “Nuclear Receptor LRH-1 Induces the Reproductive Neuropeptide Kisspeptin in the Hypothalamus” by Atkin et al (freely available at http://mend.endojournals.org/) provides novel insights into the molecular mechanism controlling kisspeptin’s differential secretion. The authors show that mice lacking LRH-1 in kisspeptin neurons have reduced plasma FSH levels and corresponding defects in follicle maturation and ovulation in the ovary. These knockout mice have a prolonged estrous cycle and deliver fewer pups per litter. On a molecular level, these findings help explain why kisspeptin is differentially regulatedindistinctregionsofthehypothalamus,thearcuate and anteroventral periventricular nuclei, and have revealed an important role for LRH-1 in regulating the female reproductive axis. Groba et al’s “Hypothyroidism Compromises Hypothalamic Leptin Signaling in Mice” reveals that leptin signaling in hypothalamic arcuate neurons is compromised under hypothyroid conditions. Activation of the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathways by leptin is reduced in hypothyroid obese (ie, ob/ob) mice as evidenced by reduced phopho-STAT3 immunoreactivity and decreased SOCS3 expression. A diminished reduction in body weight and food intake in hypothyroid ob/ob mice was observed after leptin treatment. Importantly, hypothyroidism is associated with elevated transcript levels of shorter leptin receptor isoforms. Consequently, up-regulation of the shorter isoforms of the leptin receptor may represent a major mechanism by which hypothyroidism influences the leptin signaling pathway in hypothyroid mice.

Hypogonadism in a Patient with Two Novel Mutations of the Luteinizing Hormone β-Subunit Gene Expressed in a Compound Heterozygous Form

LH gene mutations are rare; only four mutations have been described. The affected individuals are hypogonadal. We describe the clinical features of a 31-yr-old man who presented with delayed puberty and azoospermia and was found to have hypogonadism associated with an absence of circulating LH. The patient had a 12-bp deletion in exon 2 in the LH β-subunit gene and a mutation of the 5' splice site IVS2+1G→T in the same gene present in a compound heterozygous state. The first mutation predicts a deletion of four leucines of the hydrophobic core of the signal peptide. The second mutation disrupts the splicing of mRNA, generating a gross abnormality in the processing. The patient's heterozygous parents were clinically normal. The phenotype of a 16-yr-old sister of the proband, carrying the same mutations, was characterized by normal pubertal development and oligomenorrhea. This report unravels two novel mutations of the LH gene critical for synthesis and activity of the LH molecule. The insight gained from the study is that normal pubertal maturation in women can occur in a state of LH deficiency, whereas LH is essential for maturation of Leydig cells and thus steroidogenesis, puberty, and spermatogenesis in man. These mutations should be considered in girls and boys with selective deficiency of LH.

Editorial: Molecular Endocrinology Articles in the Spotlight for April 2012

We are pleased to feature the following articles in this month’s issue of Molecular Endocrinology. Interestingly, the 3 articles provide novel insights into various hypothalamic pathways that regulate important aspects of reproduction and metabolism. In “GnRH Pulse Frequency-Dependent Stimulation of FSH Transcription Is Mediated via Activation of PKA and CREB,” Thompson et al provide a mechanism of GnRH pulse frequency-dependent activation of FSH involving differential activation of protein kinase A (PKA) and subsequent differential levels of cAMP-responsive element-binding protein (CREB) phosphorylation. LH gene expression is unaffected by this pathway. Furthermore, GnRH preferentially stimulates CREB phosphorylation at slow pulse frequencies, whereas PKA (the main regulator of CREB phosphorylation in the murine LT2 gonadotrope cell model) activity increases to a greater extent at slow GnRH pulse frequencies, correlating with the increase in CREB phosphorylation. Because pulsatile GnRHregulatestheexpressionandsecretionofbothFSH and LH, this work identifies the intracellular mechanism downstream of GnRH receptor activation responsible for triggering the diverse reproductive consequences of the individual gonadotropins. “Nuclear Receptor LRH-1 Induces the Reproductive Neuropeptide Kisspeptin in the Hypothalamus” by Atkin et al (freely available at http://mend.endojournals.org/) provides novel insights into the molecular mechanism controlling kisspeptin’s differential secretion. The authors show that mice lacking LRH-1 in kisspeptin neurons have reduced plasma FSH levels and corresponding defects in follicle maturation and ovulation in the ovary. These knockout mice have a prolonged estrous cycle and deliver fewer pups per litter. On a molecular level, these findings help explain why kisspeptin is differentially regulatedindistinctregionsofthehypothalamus,thearcuate and anteroventral periventricular nuclei, and have revealed an important role for LRH-1 in regulating the female reproductive axis. Groba et al’s “Hypothyroidism Compromises Hypothalamic Leptin Signaling in Mice” reveals that leptin signaling in hypothalamic arcuate neurons is compromised under hypothyroid conditions. Activation of the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathways by leptin is reduced in hypothyroid obese (ie, ob/ob) mice as evidenced by reduced phopho-STAT3 immunoreactivity and decreased SOCS3 expression. A diminished reduction in body weight and food intake in hypothyroid ob/ob mice was observed after leptin treatment. Importantly, hypothyroidism is associated with elevated transcript levels of shorter leptin receptor isoforms. Consequently, up-regulation of the shorter isoforms of the leptin receptor may represent a major mechanism by which hypothyroidism influences the leptin signaling pathway in hypothyroid mice.