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Publication
Journal: Trends in Immunology
March/7/2005
Abstract
Understanding how selected tissue sites establish immune privilege (IP) is of interest to both basic immunology and clinical medicine: it provides novel insights into autoimmunity, fetal and allotransplant rejection and tumor escape from immunosurveillance. Here, we review why the hair follicle can serve as a uniquely accessible, widely available and instructive model for studying the establishment, maintenance, collapse and restoration of IP. The hair follicle epithelium rhythmically generates, maintains and deconstructs an area of relative IP, characterized by very low expression of MHC Ia and suppressed MHC II-dependent antigen presentation, accompanied by the local production of potent immunosuppressants capable of downregulating MHC I (e.g. transforming growth factor-beta1, alpha-melanocyte-stimulating hormone). We discuss the physiological functions of hair follicle IP, illustrate its clinical and therapeutic relevance by focusing on alopecia areata, an autoimmune hair loss disorder, and outline important unanswered questions for future research into one of nature's most intriguing and abundant, yet commonly ignored, sites of IP.
Publication
Journal: American Journal of Surgical Pathology
May/28/2008
Abstract
Patients affected by the multiple endocrine neoplasia type I syndrome (MEN1) display a high incidence of pituitary adenomas, though it is still unknown whether these pituitary tumors have specific pathologic features that would distinguish them from sporadic pituitary adenomas. Pituitary tissue specimens of 77 MEN1 patients from the GTE (Groupe d'étude des Tumeurs Endocrines) register were compared with unselected 2509 non-MEN1 sporadic pituitary tumors and also to a control subgroup of 296 cases, where 1 MEN1 tumor was matched with 4 sporadic tumors of the same hormonal immunoprofile. Sex, age, size, and invasiveness of tumors, and menin gene mutations were documented. Histologic analysis took into account 33 items, including immunocytochemical data, the proliferative marker Ki-67, and an examination of the juxtatumoral pituitary. MEN1 tumors were significantly larger and more often invasive by histology. MEN1 patients with large pituitary tumors (grade IV) were younger than non-MEN1 patients. MEN1 tumors had no other characteristic histologic features and no predominance of any one hormone producing subtype. However, plurihormonal adenomas versus monohormonal and nonimmunoreactive adenomas were more frequent in MEN1 tumors (39%) than in the control non-MEN1 group (P = 0.001). Especially, the growth hormone and prolactin plurihormonality with unusual association with follicle-stimulating hormone, luteinizing hormone, or adrenocorticotropic hormone was more frequent in MEN1 tumors. In addition, multiple adenomas were significantly more frequent (4% vs. 0.1%; P < 0.0001), especially prolactin-adrenocorticotropic hormone. Somatotroph hyperplasia, with or without a microadenoma was found in only 3 MEN1 patients, with growth hormone-releasing hormone hypersecretion by a pancreatic tumor in 2 of them. All types of mutation were observed, including frameshifts, nonsenses, missenses, and 1 case of germline MEN1 encompassing large deletion, strongly suggesting the absence of any phenotype-genotype correlation.
Publication
Journal: Reproductive Biology and Endocrinology
November/21/2011
Abstract
BACKGROUND
Effects of androgens on follicle maturation have been controversial for some time. Here, we review the potential of their applications in improving human ovulation induction, based on human and animal data, reported in the literature.
METHODS
We reviewed the published literature for the years 2005-2011, using relevant key words, in PubMed, Medline and Cochrane reviews, and then performed secondary reviews of referenced articles, which previously had not been known or preceded the searched time period. A total of 217 publications were reviewed.
RESULTS
Contrary to widely held opinion, recent data, mostly developed in the mouse, convincingly demonstrate essential contribution of androgens to normal follicle maturation and, therefore, female fertility. Androgens appear most engaged at preantral and antral stages, primarily affect granulosa cells, and exert effects via androgen receptors (AR) through transcriptional regulation but also in non-genomic ways, with ligand-activated AR modulating follicle stimulating hormone (FSH) activity in granulosa cells. While some androgens, like testosterone (T) and dehydroepiandrosterone (DHEA), appear effective in improving functional ovarian reserve (FOR) in women with diminished ovarian reserve (DOR), others may even exert opposite effects. Such differences in androgens may, at least partially, reflect different levels of agonism to AR.
CONCLUSIONS
Selective androgens appear capable of improving early stages of folliculogenesis. They, therefore, may represent forerunners of a completely new class of ovulation-inducing medications, which, in contrast to gonadotropins, affect follicle maturation at much earlier stages.
Publication
Journal: Human Reproduction
September/7/2000
Abstract
A multicentre, open-label, randomized study of the gonadotrophin-releasing hormone (GnRH) antagonist ganirelix (Orgalutran((R))/Antagon((TM))) was performed in women undergoing ovarian stimulation with recombinant FSH (rFSH: Puregon((R))). The study was designed as a non-inferiority study using a long protocol of buserelin (intranasal) and rFSH as a reference treatment. A total of 730 subjects was randomized in a treatment ratio of 2:1 (ganirelix:buserelin) using an interactive voice response system which stratified for age, type of infertility and planned fertilization procedure [IVF or intracytoplasmic sperm injection (ICSI)]. The median duration of GnRH analogue treatment was 5 days in the ganirelix group and 26 days in the buserelin group, whereas the median total rFSH dose was 1500 IU and 1800 IU respectively. In addition, in the ganirelix group the mean duration of stimulation was 1 day shorter. During ganirelix treatment the incidence of LH rises (LH>>/=10 IU/l) was 2.8% versus 1.3% during rFSH stimulation in the buserelin group. On the day of triggering ovulation by human chorionic gonadotrophin (HCG), the mean number of follicles>>/=11 mm diameter was 10.7 and 11.8, and the median serum oestradiol concentrations were 1190 pg/ml and 1700 pg/ml in the ganirelix and buserelin groups respectively. The mean number of oocytes per retrieval was 9.1 and 10.4 respectively, whereas the mean number of good quality embryos was 3.3 and 3.5 respectively. The fertilization rate was equal in both groups (62.1%), and the same mean number of embryos (2.2) was replaced. The mean implantation rates were 15.7% and 21.8%, and the ongoing pregnancy rates per attempt were 20.3% and 25.7% in the ganirelix and buserelin groups respectively. Evaluation of all safety data indicated that the ganirelix regimen was safe and well tolerated. The overall incidence of ovarian hyperstimulation syndrome was 2.4% in the ganirelix group and 5.9% in the reference group. The results of this study support a safe, short and convenient treatment regimen of ganirelix, resulting in a good clinical outcome for patients undergoing ovarian stimulation for IVF or ICSI.
Publication
Journal: Environmental Health Perspectives
July/14/2003
Abstract
A time-related deterioration in male reproductive function caused by exposure to endocrine disrupters, including persistent organochlorines (POCs), has been hypothesized. In animal studies, POCs were found to have adverse effects on male reproductive function. However, little is known about the impact of POC exposure on reproductive parameters in men. In a study of 305 young Swedish men 18-21 years old from the general population, we correlated lipid-adjusted serum levels of 2,2',4,4',5,5' -hexachlorobiphenyl (CB-153)--an index substance for POC exposure--to markers of male reproductive function: testis size assessed by ultrasound, sperm concentration, total sperm count, sperm motility assessed manually and with a computer-aided sperm analyzer (CASA), and serum levels of follicle-stimulating hormone, inhibin B, testosterone, sexual hormone-binding globulin (SHBG), luteinizing hormone, and estradiol. We found weak but statistically significant, negative correlations between CB-153 levels and both the testosterone:SHBG ratio (r = -0.25, p < 0.001)--a measure of the biologically active free testosterone fraction--and CASA sperm motility (r = -0.13, p = 0.02). No statistically significant association with other seminal, hormonal, or clinical markers of male reproductive function was found. In previous studies of more highly POC-exposed groups of adult men, the correlation between POC exposure, including CB-153, and free testosterone levels was not statistically significant. The present study gives some tentative support for weak negative effects of CB-153 exposure on sperm motility and free testosterone levels in young men, but further semen studies on more highly exposed groups may give more firm conclusions on the hazard for male reproductive function from dietary POC exposure.
Publication
Journal: Fertility and Sterility
December/8/2002
Abstract
OBJECTIVE
To assess the effect of ovarian stimulation with recombinant FSH, GnRH antagonists, and hCG on endometrial maturation on the day of oocyte pick-up.
METHODS
Prospective study.
METHODS
Tertiary referral center.
METHODS
Fifty-five women undergoing controlled ovarian hyperstimulation for IVF/intracytoplasmic sperm injection (ICSI).
METHODS
[1] Ovarian stimulation with recombinant FSH, starting on day 2 of the cycle and GnRH antagonist, starting after a median of 6 days of recombinant FSH stimulation (range, 5-12 days); [2] hCG administration for ovulation induction; and [3] aspirational biopsy of endometrium at oocyte pick-up.
METHODS
Endometrial histology at oocyte pick-up by Noyes criteria.
RESULTS
Advancement of endometrial maturation (2.5 +/- 0.1 days) as compared to the expected chronological date was observed in all antagonist cycles at oocyte retrieval. Endometrial advancement at oocyte pick-up increased in line with values of LH at initiation of stimulation and the duration of recombinant FSH treatment before the antagonist was started.
CONCLUSIONS
The higher the values of LH at initiation of stimulation and the longer the duration of recombinant FSH treatment before the antagonist is started, the more advanced the endometrial maturation at oocyte pick-up.
Publication
Journal: Human Reproduction Update
April/18/2000
Abstract
Human male infertility is often related to chromosome abnormalities. In chromosomally normal infertile males, the rates of chromosome 21 and sex chromosome disomy in spermatozoa are increased. Higher incidences of trisomy 21 (seldom of paternal origin) and sex chromosome aneuploidy are also found. XXY and XYY patients produce increased numbers of XY, XX and YY spermatozoa, indicating an increased risk of production of XXY, XYY and XXX individuals. Since XXYs can reproduce using intracytoplasmic sperm injection (ICSI), this could explain the slight increase of sex chromosome anomalies in ICSI series. Carriers of structural reorganizations produce unbalanced spermatozoa, and risk having children with duplications and/or deficiencies. In some cases, this risk is considerably lower or higher than average. These patients also show increased diploidy, and a higher risk of producing diandric triploids. Meiotic disorders are frequent in infertile males, and increase with severe oligoasthenozoospemia (OA) and/or high follicle stimulating hormone (FSH) concentrations. These patients produce spermatozoa with autosomal and sex chromosome disomies, and diploid spermatozoa. Their contribution to recurrent abortion depends on the production of trisomies, monosomies and of triploids. The most frequent sperm chromosome anomaly in infertile males is diploidy, originated by either meiotic mutations or by a compromised testicular environment.
Publication
Journal: Journal of Neuroendocrinology
March/7/2010
Abstract
The kisspeptin/Gpr54 signalling pathway plays a critical role in reproduction by stimulating the secretion of gonadotrophin-releasing hormone (GnRH), yet mice carrying mutations in Kiss1 (which encodes kisspeptin) or Gpr54 exhibit partial sexual maturation. For example, a proportion of female Kiss1(-/-) and Gpr54(-/-) mice exhibit vaginal oestrus, and some male Kiss1(-/-) and Gpr54(-/-) mice exhibit spermatogenesis. To characterise this partial sexual maturation, we examined the vaginal cytology of female Kiss1(-/-) and Gpr54(-/-) mice over time. Almost all mutant mice eventually enter oestrus, and then spontaneously transition from oestrus to dioestrus and back to oestrus again. These transitions are not associated with ovulation, and the frequency of these transitions increases with age. The oestrus exhibited by female Kiss1(-/-) and Gpr54(-/-) mice was disrupted by the administration of the competitive GnRH antagonist acyline, which also resulted in lower uterine weights and, in Kiss1(-/-) mice, lower serum follicle-stimulating hormone (FSH) and luteinising hormone (LH) concentrations. Similarly, male Kiss1(-/-) and Gpr54(-/-) mice treated with acyline had smaller testicular sizes and an absence of mature sperm. In addition to examining intact Kiss1(-/-) and Gpr54(-/-) mice, we also assessed the effects of acyline on gonadotrophin concentrations in gonadectomised mice. Gonadectomy resulted in a significant increase in serum FSH concentrations in male Gpr54(-/-) and Kiss1(-/-) mice. Acyline administration to gonadectomised Kiss1(-/-) and Gpr54(-/-) male mice lowered serum FSH and LH concentrations significantly. By contrast to males, gonadectomy did not result in significant gonadotrophin changes in female Kiss1(-/-) and Gpr54(-/-) mice, but acyline administration was followed by a decrease in LH concentrations. These results demonstrate that, although kisspeptin signalling is critical for the high levels of GnRH activity required for normal sexual maturation and for ovulation, Kiss1(-/-) and Gpr54(-/-) mice retain some degree of GnRH activity. This GnRH activity is sufficient to produce significant effects on vaginal cytology and uterine weights in female mice and on spermatogenesis and testicular weights in male mice.
Publication
Journal: Endocrinology
June/20/1996
Abstract
Hormonal regulation of apoptosis has been studied in cultured preovulatory follicles. Because early antral follicles are most vulnerable to undergo atretic degeneration under physiological conditions in vivo, the present studies were designed to investigate the hormonal regulation of apoptosis using in vitro culture of early antral follicles. Rats were implanted with diethylstilbestrol at 24 days of age to stimulate the development of early antral follicles, and ovaries were collected at day 27 of age. Early antral follicles were dissected and cultured (four per vial) for 24 h with or without hormonal treatments. After culture, DNA was extracted from follicles, and the degree of apoptotic DNA fragmentation was determined using 3'-end labeling and gel electrophoresis. In situ analysis of apoptotic DNA fragmentation revealed that granulosa cells in these follicles are the main cell type undergoing apoptosis. Follicles cultured in the absence of hormones showed a 12-fold increase in the level of apoptotic DNA fragmentation which was prevented by treatment with FSH in a dose-dependent manner (60% maximal suppression and apparent ED50 of 30 ng/ml). Similarly, treatment with (Bu)2cAMP also suppressed follicle apoptosis. Treatment with LH or human CG, however, minimally suppressed apoptotic DNA fragmentation (35% maximal suppression). Insulin-like growth factor-I (IGF-I) also suppressed apoptosis by 45%. Moreover, the suppressive effect of FSH on apoptosis was partially reversed by coincubation with IGF-binding protein-3, suggesting a potential mediatory role of endogenous IGF-I. However, recombinant bovine GH had no effect on follicle apoptosis despite its ability to stimulate IGF-I messenger RNA (mRNA) levels. Incubation of follicles with epidermal growth factor (EGF) and basic fibroblast growth factor maximally suppressed follicle apoptosis by only 32% and 42%, respectively. Ligand binding analysis indicated the minimal effectiveness of EGF on apoptosis in early antral follicles, as compared with its potent action in preovulatory follicles reported earlier, may be due to a 3.5 fold increase in EGF receptor concentration in the mature follicles. High doses (150 or 500 ng/ml) of interleukin-1beta also suppressed apoptosis by 48% whereas treatment with an NO generator, sodium nitroprusside, or a cyclic GMP analog suppressed apoptosis as effectively as that of FSH. Furthermore, treatment with activin resulted in a dose-related suppression of follicle apoptosis, reaching a maximal 40% suppression. In contrast, cotreatment of activin with its binding protein, follistatin, abolished this effect. Collectively, these data demonstrated a stage-dependent difference in the hormonal regulation of follicle apoptosis. Although FSH, LH/human CG, GH, IGF-I, EGF, basic fibroblast growth factor, and interleukin-1beta are all effective survival factors for preovulatory follicles, FSH is a major survival factor for early antral follicles, the stage during which a majority of follicle undergo atresia under physiological conditions.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
July/24/1988
Abstract
Follistatin is a single-chain gonadal protein that specifically inhibits follicle-stimulating hormone release. By use of the recently characterized porcine follistatin cDNA as a probe to screen a human testis cDNA library and a genomic library, the structure of the complete human follistatin precursor as well as its genomic organization have been determined. Three of eight cDNA clones that were sequenced predicted a precursor with 344 amino acids, whereas the remaining five cDNA clones encoded a 317 amino acid precursor, resulting from alternative splicing of the precursor mRNA. Mature follistatins contain four contiguous domains that are encoded by precisely separated exons; three of the domains are highly similar to each other, as well as to human epidermal growth factor and human pancreatic secretory trypsin inhibitor. The genomic organization of the human follistatin is similar to that of the human epidermal growth factor gene and thus supports the notion of exon shuffling during evolution.
Publication
Journal: Cancer Research
February/21/1982
Abstract
The effects of the pineal hormone, melatonin, and of pinealectomy on the incidence of mammary adenocarcinoma in Sprague-Dawley rats treated with 7,12-dimethylbenz(alpha)-anthracene (DMBA) were investigated. Melatonin (2.5 mg/kg), begun on the same day as DMBA (5 mg) treatment and given daily in the afternoon for 90 days, significantly reduced the incidence of mammary tumors from 79% (control) to 20% (treated) (p less than 0.002). Rats pinealectomized at 20 days of age and treated with 7 mg of DMBA at 50 days of age had a higher incidence of tumors (88%) compared to control animals (22%). Fifteen mg of DMBA, which resulted in a higher incidence of tumors, reduced the difference between pinealectomized and control animals. Melatonin only partially reversed the effects of pinealectomy, reducing the incidence from 87% (pinealectomy alone) to 63% (pinealectomy plus melatonin); however, the tumor incidence was still lower (27%) in nonpinealectomized, melatonin-treated animals. Assessment of plasma prolactin, luteinizing hormone, follicle-stimulating hormone, estradiol, and cortisol in DMBA-treated tumor-free and tumor-bearing animals revealed a significantly lower plasma prolactin concentration [27 +/- 5 (S.E.) ng/ml] in melatonin-treated animals as compared to vehicle-treated animals [65 +/- 8 ng/ml]. The concentration of plasma prolactin was less in melatonin-treated, pinealectomized rats (55 +/- 10 ng/ml) as compared to vehicle-treated, pinealectomized animals (101 +/- 13 ng/ml). Other hormones were not affected by melatonin treatment. These data support the hypothesis that melatonin inhibits the development of DMBA-induced mammary tumors in the rat while removal of the pineal gland stimulates development of such tumors. Additionally, these experiments provide evidence that these effects may be mediated by a suppression of plasma prolactin levels.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
January/29/1973
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
February/19/1996
Abstract
Anovulation in polycystic ovary syndrome (PCOS) is associated with hyperinsulinemia and insulin resistance, but it has been unclear whether the ovary is insulin resistant in women with PCOS. The aims of this study were, firstly, to determine whether human granulosa cells respond to physiological concentrations of insulin and, secondly, to investigate insulin and gonadotropin interactions in vitro in granulosa cells obtained from normal (N) and polycystic ovaries (PCO). Granulosa cells were incubated with insulin with or without gonadotropins for 48 h. Insulin augmented not only basal production of estradiol and progesterone, but also LH-stimulated steroid accumulation in granulosa cell cultures from N and PCO. Insulin enhanced FSH-stimulated progesterone production by granulosa cells from N and PCO, but the effect on FSH-stimulated estradiol production was variable, ranging from no effect for granulosa cells from N to synergistic for granulosa cells from PCO of anovulatory subjects. Preincubation with insulin for 48 h increased subsequent basal and LH-induced, but not FSH-stimulated, steroid production. These data demonstrate that granulosa cells from PCO respond to insulin despite the association, in vivo, of PCOS with peripheral insulin resistance. Insulin preincubation enhances the subsequent response of human granulosa cells to LH. We propose that in anovulatory women with PCOS, elevated levels of insulin interacting with LH may contribute to the mechanism of anovulation.
Publication
Journal: Science
January/6/1987
Abstract
The hypogonadal (hpg) mouse lacks a complete gonadotropin-releasing hormone (GnRH) gene and consequently cannot reproduce. Introduction of an intact GnRH gene into the genome of these mutant mice resulted in complete reversal of the hypogonadal phenotype. Transgenic hpg/hpg homozygotes of both sexes were capable of mating and producing offspring. Pituitary and serum concentrations of luteinizing hormone, follicle-stimulating hormone, and prolactin were restored to those of normal animals. Immunocytochemistry and in situ hybridization showed that GnRH expression was restored in the appropriate hypothalamic neurons of the transgenic hpg animals, an indication of neural-specific expression of the introduced gene.
Publication
Journal: Carcinogenesis
November/23/2008
Abstract
The mechanisms of granulosa cell tumor (GCT) development may involve the dysregulation of signaling pathways downstream of follicle-stimulating hormone, including the phosphoinosite-3 kinase (PI3K)/AKT pathway. To test this hypothesis, a genetically engineered mouse model was created to derepress the PI3K/AKT pathway in granulosa cells by conditional targeting of the PI3K antagonist gene Pten (Pten(flox/flox);Amhr2(cre/+)). The majority of Pten(flox/flox);Amhr2(cre/+) mice featured no ovarian anomalies, but occasionally ( approximately 7%) developed aggressive, anaplastic GCT with pulmonary metastases. The expression of the PI3K/AKT downstream effector FOXO1 was abrogated in Pten(flox/flox);Amhr2(cre/+) GCT, indicating a mechanism by which GCT cells may increase proliferation and evade apoptosis. To relate these findings to spontaneously occurring GCT, analyses of PTEN and phospho-AKT expression were performed on human and equine tumors. Although PTEN loss was not detected, many GCT (2/5 human, 7/17 equine) featured abnormal nuclear or perinuclear localization of phospho-AKT, suggestive of altered PI3K/AKT activity. As inappropriate activation of WNT/CTNNB1 signaling causes late-onset GCT development and cross talk between the PI3K/AKT and WNT/CTNNB1 pathways has been reported, we tested whether these pathways could synergize in GCT. Activation of both the PI3K/AKT and WNT/CTNNB1 pathways in the granulosa cells of a mouse model (Pten(flox/flox);Ctnnb1(flox(ex3)/+);Amhr2(cre/+)) resulted in the development of GCT similar to those observed in Pten(flox/flox);Amhr2(cre/+) mice, but with 100% penetrance, perinatal onset, extremely rapid growth and the ability to spread by seeding into the abdominal cavity. These data indicate a synergistic effect of dysregulated PI3K/AKT and WNT/CTNNB1 signaling in the development and progression of GCT and provide the first animal models for metastatic GCT.
Publication
Journal: Science
August/9/1973
Abstract
Ovariectomized female rats treated with estrogen, in dosages too low to provoke mating, displayed this behavior when given subcutaneous injections of synthetic luteinizing hormone-releasing factor (LRF) 48 hours later. Two hours after the injection of LRF, components of female sexual behavior appeared. The lordosis reflex followed mounting by the male, and darting and hopping behavior was quite prevalent. On the other hand, treatment with estrogen followed by luteinizing hormone, follicle-stimulating hormone, or thyrotropin-releasing factor did not induce copulatory behavior. The results suggest that LRF may play a role in induction of mating behavior.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
December/19/1996
Abstract
Women experience a decline in fertility that precedes the menopause by several years. Previous studies have demonstrated a monotropic rise in FSH associated with reproductive aging: however, the mechanism of this rise and its role in the aging process are poorly understood. The purpose of this study was to characterize ovarian follicular development and ovarian hormone secretion in older reproductive age women. Sixteen women, aged 40-45 yr, with regular ovulatory cycles were studied. The control group consisted of 12 ovulatory women, aged 20-25 yr. Serum obtained by daily blood sampling was analyzed for FSH, LH, estradiol (E), progesterone, and inhibin (Monash polyclonal assay). Follicle growth and ovulation were documented by transvaginal ultrasound. Older women had significantly higher levels of FSH throughout the menstrual cycle. E, progesterone, LH, and inhibin levels did not differ between the two age groups when compared relative to the day of the LH surge. Ultrasound revealed normal growth, size, and collapse of a dominant follicle in all subjects. Older women had significantly shorter follicular phase length associated with an early acute rise in follicular phase E, reflecting accelerated development of a dominant follicle. We conclude that older reproductive age women have accelerated development of a dominant follicle in the presence of the monotropic FSH rise. This is manifested as a shortened follicular phase and elevated follicular phase E. The fact that ovarian steroid and inhibin secretion were similar to those in the younger women suggests that elevated FSH in women of advanced reproductive age may represent a primary neuroendocrine change associated with reproductive aging.
Publication
Journal: Endocrinology
January/5/2009
Abstract
GnRH1 stimulates the synthesis and secretion of FSH and LH from the anterior pituitary gland. The molecular mechanisms through which GnRH1 produces these effects in humans have not been determined. Here, we examined transcriptional regulation of the human FSHbeta (FSHB) subunit using reporter assays in immortalized murine gonadotrope cells. GnRH1 dose and time dependently stimulated FSHB promoter activity, with peak stimulation occurring at 8 h. GnRH1 rapidly stimulated various MAPK cascades, though the ERK1/2 and p38 pathways appeared to be most critical for FSHB induction. Indeed, constitutively active forms of both Raf1 kinase and MAP2K6 (MKK6) were sufficient to stimulate reporter activity. GnRH1 stimulated activator protein-1 (AP-1) (FosB, c-fos, JunB, and cJun) synthesis and complex formation, the latter of which bound to a conserved cis-element within -120 bp of the transcription start site. A second, lower affinity, site was mapped more proximally. Mutations of both cis-elements diminished GnRH1-stimulated promoter activity, though disruption of the higher affinity site had a more dramatic effect. A dominant-negative Fos protein dose dependently inhibited GnRH1-stimulated FSHB transcription, confirming a role for endogenous AP-1 proteins. MAPK kinase 1 (MEK1) and p38 inhibitors significantly attenuated GnRH1-stimulated c-fos, FosB, and JunB synthesis, suggesting a mechanism whereby the ERK1/2 and p38 signaling pathways regulate FSHB transcription. Activins and inhibins potently regulate FSH synthesis in rodents, but their roles in FSH regulation in humans are less clear. Activin A, though weak on its own, synergized with GnRH1 to stimulate human FSHB promoter activity. In contrast, activin A partially inhibited GnRH1-stimulated LHbeta subunit (LHB) transcription. The GnRH1 and activin A signaling pathways appear to converge at the level of the high-affinity AP-1 site. Fos and Jun proteins synergistically regulate reporter activity through this element, and their effects are potentiated by coexpression of either Smad2 or Smad3, effectors in the activin signaling cascade. In summary, GnRH1 and activin A synergistically regulate human FSHB subunit transcription. The combined actions of AP-1 and Smad proteins acting through a conserved AP-1 element provide a candidate mechanism for this effect. The ability of activins to potentiate selectively the effects of GnRH1 on FSHB expression suggests a model for preferential increases in FSH secretion at the luteal-follicular transition of the menstrual cycle.
Publication
Journal: Human Reproduction
June/14/1998
Abstract
Idiopathic Sertoli cell-only syndrome (SCOS) is characterized by azoospermia, small testes, absence of germ cells in the testes, elevated follicle stimulating hormone and normal testosterone concentrations. The Y-chromosome is involved in the regulation of spermatogenesis and in the pathogenesis of a fraction of idiopathic male infertility. An azoospermia factor (AZF) is present on the Y-chromosome long arm euchromatic region (Yq11) and two gene families (DAZ and RBM) have been identified within this region. The aim of this study was to investigate whether a specific pattern of Yq11 microdeletions may be associated with idiopathic SCOS. Eighteen idiopathic subjects showing a testicular cytological picture of bilateral SCOS were selected and tested by polymerase chain reaction for a set of 29 Y-specific sequence-tagged sites (STS). We found Yq microdeletions in 10 out of 18 patients (55.5%) while the fathers or brothers of six out of 10 patients deleted for Yq were shown to carry an intact Y-chromosome. These deletions may therefore be considered as de-novo deletions and the cause of SCOS. The analysis of the microdeletions allowed us to identify two homogeneous regions that have a high incidence of deletion. The smallest deletion, common to all patients, is located in Yq interval 5. We therefore speculate that there is a relationship between specific, well-characterized Yq11 microdeletions and a testicular picture of SCOS, identifying an Y-related region frequently deleted in this syndrome. In conclusion, the findings of this study demonstrate that a large percentage of idiopathic SCOS may be genetically determined and identify an Y-related region that seems to possess one or more still unknown genes essential for spermatogenesis.
Publication
Journal: Human Reproduction
February/23/1999
Abstract
A multicentre, double-blind, randomized dose-finding study of Org 37462 (ganirelix) was conducted in 333 women undergoing ovarian stimulation with recombinant follicle stimulating hormone (rFSH; Puregon) to establish the minimal effective dose preventing premature luteinizing hormone (LH) surges during ovarian stimulation. For ovarian stimulation, rFSH was given in a fixed daily dose of 150 IU for 5 days from days 2 to 6 of the menstrual cycle. From cycle day 7 onward, up to and including the day of human chorionic gonadotrophin (HCG), Org 37462 (dosages 0.0625, 0.125, 0.25, 0.5, 1.0 and 2.0 mg/0.5 ml) was administered once daily by s.c. injection, and the rFSH dose was adjusted depending on ovarian response. The lowest (0.0625 mg) and highest (2.0 mg) dose groups were terminated prematurely on the advice of an external independent advisory committee. Serum Org 37462 concentrations increased in a linear dose-proportional manner, whereas serum LH and increases of oestradiol fell with increasing Org 37462 dose. During Org 37462 treatment, serum LH concentrations>> or =10 IU/l were observed in the lowest dose groups with incidences of 16% (0.0625 mg), 9% (0.125 mg) and 1.4 % (0.25 mg). On the day of HCG, the number of follicles>> or =11,>> or =15 and>> or =17 mm were similar in the six dose groups, whereas serum oestradiol concentrations were highest in the 0.0625 mg group (1475 pg/ml) and lowest in the 2 mg group (430 pg/ml). The median daily dose of rFSH was between 150 and 183 IU and the overall median duration of Org 37462 treatment was approximately 5 days in the six treatment groups. Overall, Org 37462 treatment appeared to be safe and well tolerated. The mean number of recovered oocytes and good-quality embryos was similar in all dose groups and ranged from 8.6 to 10.0 and 2.5 to 3.8, respectively. The mean number of replaced embryos in the different dose groups ranged from 2.3 to 2.7. The implantation rate was highest in the 0.25 mg group (21.9%) and lowest in the 2 mg group (1.5%). The early miscarriage rates (first 6 weeks after embryo transfer) were 11.9 and 13% in the 1 and 2 mg group respectively, whereas in the other dose groups this incidence was zero (0.0625%) up to a maximum of 3.7% (0.5 mg group). The vital pregnancy rate (with heart activity) at 5-6 weeks after embryo transfer was highest in the 0.25 mg group, i.e. 36.8 % per attempt and 40.3 % per transfer, and resulted in an ongoing pregnancy rate 12-16 weeks after embryo transfer of 33.8% per attempt and 37.1% per transfer. In conclusion, a daily dose of 0.25 mg Org 37462 prevented LH surges during ovarian stimulation and resulted in a good clinical outcome.
Publication
Journal: Journal of Investigative Dermatology
September/20/2006
Abstract
The melanocortin (MC) system is probably the best characterized neuropeptide network of the skin. Most cutaneous cell types express MC receptors (MC-Rs) and synthesize MCs, such as alpha-melanocyte-stimulating hormone (alpha-MSH), that act in autocrine and paracrine fashion. In human skin cells, activation of adenylate cyclase by MCs occurs at 10(-6)-10(-9) M doses of the ligand, but effects are induced in some cell types at subnanomolar concentrations. In addition to the pigmentary action of MCs on epidermal melanocytes, the hair follicle is a source and target for MCs. MCs regulate lipogenesis in sebocytes expressing both MC-1R and MC-5R. In adipocytes, lipid metabolism is modulated by agouti signalling protein, a natural MC-1R/MC-4R antagonist. The anti-inflammatory activity of alpha-MSH includes immunomodulatory effects on several resident skin cells and antifibrogenic effects mediated via MC-1R expressed by dermal fibroblasts. In human mast cells, alpha-MSH appears to be proinflammatory due to histamine release. alpha-MSH exhibits cytoprotective activity against UVB-induced apoptosis and DNA damage, a finding that helps explain the increased risk of cutaneous melanoma in individuals with loss of function MC-1R mutations. These findings should improve our understanding of skin physiology and pathophysiology and may offer novel strategies with MCs as future therapeutics for skin diseases.
Publication
Journal: Journal of Physiology
May/22/2006
Abstract
Recent studies demonstrate long-term programming of function of specific organ systems resulting from suboptimal environments during fetal life and development up to weaning. Nutrient restriction during pregnancy and lactation impairs overall fetal growth and development. We determined the effects of maternal protein restriction (MPR; 50% normal protein intake) during fetal development and/or lactation in rats on the function and ageing of the reproductive system of female progeny. Rats were fed either a control 20% casein diet (C) or a restricted diet (R) of 10% casein during pregnancy. After delivery mothers received either C or R diet until weaning to provide four groups, CC, RR, CR and RC. We report data on female offspring only. After weaning pups were fed the C diet. MPR increased maternal progesterone, corticosterone, oestradiol and testosterone concentrations at 19 days gestation. Reproductive and somatic phenotype was altered as pup birth weight was decreased, and ano-genital distance was increased by MPR. Pup corticosterone was decreased at 2 days postnatal (PN) life. Vaginal opening and timing of the first oestrus were delayed in RR and CR and these differences were not related to body weight. At 21 days PN oestradiol in RR and CR and progesterone in RR were reduced; at 70 days PN luteinizing hormone (LH) in all restricted groups was reduced in dioestrus while follicle stimulating hormone (FSH) was unchanged. Cycle length increased between 140 days and 1 year in RR and CR but remained unchanged in CC, providing evidence of premature ageing of reproductive function. Fertility rates declined over the same period in the three experimental groups but not CC. MPR in one of the two experimental periods, either pregnancy or lactation, resulted in decreased pup survival compared with CC and RR. These data show that MPR results in delayed sexual maturation and premature ageing of reproductive function.
Publication
Journal: JAMA - Journal of the American Medical Association
February/29/1996
Abstract
OBJECTIVE
To prospectively examine the association between endogenous hormones and development of ovarian cancer.
METHODS
Nested case-control study.
METHODS
A population-based serum bank in Washington County, Maryland.
METHODS
Serum samples were collected in 1974 from 20305 county residents and stored at -70 degrees C. From 1975 through 1989, a total of 31 cases of ovarian cancer were identified in women who were not taking hormones at the time of blood collection. These cases were matched to 62 controls on age, menopausal status, and, for premenopausal women, number of days from the beginning of the last menstrual period.
METHODS
Prediagnostic endogenous hormone levels of cases and controls were compared.
RESULTS
Mean follicle-stimulating hormone levels were lower among cases (43.3 IU/L) compared with controls (54.4 IU/L) (P = .04), and increasing levels were associated with significantly lower risk (P for trend = .01), particularly among postmenopausal women. Luteinizing hormone levels were 9% lower among cases than controls, but the difference was not statistically significant (P = .39). Compared with controls, cases had higher androstenedione levels (4.5 nmol/L vs 3.3 nmol; P = .03) and higher dehydroepiandrosterone (DHEA) levels (15.9 nmol/L vs 9.7 nmol/L; P = .02). The risk of ovarian cancer increased with higher levels of androstenedione and DHEA sulfate (P for trend = .008 and .11, respectively). These associations were not materially different between premenopausal and postmenopausal women.
CONCLUSIONS
The results suggest that women with low serum gonadotropin levels or high androgen levels have an increased risk of ovarian cancer. These findings do not support the hypothesis that pituitary gonadotropins increase the risk of ovarian cancer. Replication of the study in other populations is highly desirable.
Publication
Journal: Obstetrics and Gynecology
September/19/2001
Abstract
OBJECTIVE
To estimate the prevalence of perceived poor sleep in women aged 35-49 years and to correlate sleep quality with levels of gonadal steroids and predictors of poor sleep.
METHODS
A cohort of 218 black and 218 white women aged 35-47 years at enrollment (aged 37-49 at final follow-up) with regular menstrual cycles was identified through random digit dialing for a longitudinal study of ovarian aging correlates. Data obtained at four assessment periods, including enrollment, over a 2-year interval were collected between days 1 and 6 (mean = 3.9) of the menstrual cycle. The primary outcome measure was subjects' rating of sleep quality at each assessment period. Associations of sleep quality with hormone levels (estradiol, follicle-stimulating hormone, luteinizing hormone, testosterone, and dehydroepiandrosterone sulfate) and other clinical, behavioral, and demographic variables were examined in bivariable and multivariable analyses.
RESULTS
Approximately 17% of subjects reported poor sleep at each assessment period. Significant independent associations with poor sleep included greater incidence of hot flashes (odds ratio [OR] 1.52; 95% confidence interval [CI] 1.08, 2.12, P =.02), higher anxiety levels (OR 1.03; 95% CI 1.00, 1.06, P =.04), higher depression levels (OR 1.05; 95% CI 1.02, 1.07, P <.001), greater caffeine consumption (OR 1.25; 95% CI 1.04, 1.49, P =.02), and lower estradiol levels in women aged 45-49 (OR 0.53; 95% CI 0.34, 0.84, P =.006), after adjustment for current use of sleep medications.
CONCLUSIONS
Both hormonal and behavioral factors were associated with sleep quality. Estradiol levels are an important factor in poor sleep reported by women in the 45-49 age group. Further evaluation of estrogen treatment for poor sleep of women 45 years and older is warranted.
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