Oocyte quality is enhanced by hypoglycosylated FSH through increased cell-to-cell interaction during mouse follicle development.

Macroheterogeneity in follicle-stimulating hormone (FSH) ß-subunit N-glycosylation results in distinct FSH glycoforms. Hypoglycosylated FSH21 is the abundant and more bioactive form in pituitaries of females under 35 years of age, whereas fully glycosylated FSH24 is less bioactive and increases with age. To investigate whether the shift in FSH glycoform abundance contributes to the age-dependent decline in oocyte quality, the direct effects of FSH glycoforms on folliculogenesis and oocyte quality were determined using an encapsulated in vitro mouse follicle growth system. Long-term culture (10-12 days) with FSH21 (10 ng/ml) enhanced follicle growth, estradiol secretion and oocyte quality compared with FSH24 (10 ng/ml) treatment. FSH21 enhanced establishment of transzonal projections, gap junctions and cell-to-cell communication within 24 h in culture. Transient inhibition of FSH21-mediated bidirectional communication abrogated the positive effects of FSH21 on follicle growth, estradiol secretion and oocyte quality. Our data indicate that FSH21 promotes folliculogenesis and oocyte quality in vitro by increasing cell-to-cell communication early in folliculogenesis, and that the shift in in vivo abundance from FSH21 to FSH24 with reproductive aging may contribute to the age-dependent decline in oocyte quality.

Revisiting the gonadotropic regulation of mammalian spermatogenesis: evolving lessons during the past decade.

Spermatogenesis is a multi-step process of male germ cell (Gc) division and differentiation which occurs in the seminiferous tubules of the testes under the regulation of gonadotropins - Follicle Stimulating Hormone (FSH) and Luteinising hormone (LH). It is a highly coordinated event regulated by the surrounding somatic testicular cells such as the Sertoli cells (Sc), Leydig cells (Lc), and Peritubular myoid cells (PTc). FSH targets Sc and supports the expansion and differentiation of pre-meiotic Gc, whereas, LH operates via Lc to produce Testosterone (T), the testicular androgen. T acts on all somatic cells e.g.- Lc, PTc and Sc, and promotes the blood-testis barrier (BTB) formation, completion of Gc meiosis, and spermiation. Studies with hypophysectomised or chemically ablated animal models and hypogonadal (hpg) mice supplemented with gonadotropins to genetically manipulated mouse models have revealed the selective and synergistic role(s) of hormones in regulating male fertility. We here have briefly summarized the present concept of hormonal control of spermatogenesis in rodents and primates. We also have highlighted some of the key critical questions yet to be answered in the field of male reproductive health which might have potential implications for infertility and contraceptive research in the future.

Follicle Selection in Mares as a Model for Illustrating the Many Hormonal and Biochemical Interactions That Drive a Single Physiological Mechanism.

The mechanism for selection of the future dominant or ovulatory follicle in mares involves a relatively abrupt separation in growth rates between the future dominant follicle and several subordinate follicles and is termed diameter deviation. The event is used to illustrate that a coordinated complex of many follicular, hormonal, and biochemical factors interact and interbalance during a single physiological mechanism. For example, a positive effect of follicle stimulating hormone (FSH) on development of all follicles during the growing phase can later involve a positive effect of luteinizing hormone (LH) but apparently only on the future dominant follicle. In turn, the developing and future dominant follicle produces estradiol which at appropriate times and degrees reduces FSH concentrations to accommodate follicle functions at certain levels of FSH. Meanwhile, the estradiol prevents LH from increasing from a useful to an adverse concentration. These interactions enmesh with the production and roles of other factors (e.g., inhibin, insulin-like growth factor) during follicle selection. The wide array of morphological, hormonal, and biochemical activities occur in harmony even when in the same tissue and often at the same time.

AMH Regulation by Steroids in the Mammalian Testis: Underlying Mechanisms and Clinical Implications.

Anti-Müllerian hormone (AMH) is a distinctive biomarker of the immature Sertoli cell. AMH expression, triggered by specific transcription factors upon fetal Sertoli cells differentiation independently of gonadotropins or sex steroids, drives Müllerian duct regression in the male, preventing the development of the uterus and Fallopian tubes. AMH continues to be highly expressed by Sertoli until the onset of puberty, when it is downregulated to low adult levels. FSH increases testicular AMH output by promoting immature Sertoli cell proliferation and individual cell expression. AMH secretion also showcases a differential regulation exerted by intratesticular levels of androgens and estrogens. In the fetus and the newborn, Sertoli cells do not express the androgen receptor, and the high androgen concentrations do not affect AMH expression. Conversely, estrogens can stimulate AMH production because estrogen receptors are present in Sertoli cells and aromatase is stimulated by FSH. During childhood, sex steroids levels are very low and do not play a physiological role on AMH production. However, hyperestrogenic states upregulate AMH expression. During puberty, testosterone inhibition of AMH expression overrides stimulation by estrogens and FSH. The direct effects of sex steroids on AMH transcription are mediated by androgen receptor and estrogen receptor α action on AMH promoter sequences. A modest estrogen action is also mediated by the membrane G-coupled estrogen receptor GPER. The understanding of these complex regulatory mechanisms helps in the interpretation of serum AMH levels found in physiological or pathological conditions, which underscores the importance of serum AMH as a biomarker of intratesticular steroid concentrations.

Morphology and Biochemistry of Ovulation.

The process of ovulation involves multiple and iterrelated genetic, biochemical, and morphological events: cessation of the proliferation of granulosa cells, resumption of oocyte meiosis, expansion of cumulus cell-oocyte complexes, digestion of the follicle wall, and extrusion of the metaphase-II oocyte. The present narrative review examines these interrelated steps in detail. The combined or isolated roles of the follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are highlighted. Genes indiced by the FSH genes are relevant in the cumulus expansion, and LH-induced genes are critical for the resumption of meiosis and digestion of the follicle wall. A non-human model for follicle-wall digestion and oocyte release was provided.

O processo de ovulação envolve modificações genéticas, bioquímicas e morfológicas múltiplas e interrelacionadas: suspensão da proliferação das células da granulosa, reinício da meiose do oócito, expansão das células do complexo cumulus-oócito, digestão da parede folicular, e extrusão do oócito. Esta revisão narrativa examina em detalhes cada um desses eventos e os principais genes e proteínas envolvidos. Mais importante, a ação combinada ou isolada do hormônio folículo-estimulante (HFE) e do hormônio luteinizante (HL) é destacada. Detalha-se o papel do HFE na expansão do cumulus e do HL na digestão da parede folicular, permitindo a extrusão do oócito na superfície ovariana. Proveu-se um modelo não humano para explicar a digestão da parede folicular.

Morphology and Biochemistry of Ovulation Morfologia e bioquímica da ovulação

Abstract The process of ovulation involves multiple and iterrelated genetic, biochemical, and morphological events: cessation of the proliferation of granulosa cells, resumption of oocyte meiosis, expansion of cumulus cell-oocyte complexes, digestion of the follicle wall, and extrusion of the metaphase-II oocyte. The present narrative review examines these interrelated steps in detail. The combined or isolated roles of the folliclestimulating hormone (FSH) and luteinizing hormone (LH) are highlighted. Genes indiced by the FSH genes are relevant in the cumulus expansion, and LH-induced genes are critical for the resumption ofmeiosis and digestion of the follicle wall. A nonhuman model for follicle-wall digestion and oocyte release was provided.

Resumo O processo de ovulação envolve modificações genéticas, bioquímicas e morfológicas múltiplas e interrelacionadas: suspensão da proliferação das células da granulosa, reinício da meiose do oócito, expansão das células do complexo cumulus-oócito, digestão da parede folicular, e extrusão do oócito. Esta revisão narrativa examina em detalhes cada um desses eventos e os principais genes e proteínas envolvidos. Mais importante, a ação combinada ou isolada do hormônio folículo-estimulante (HFE) e do hormônio luteinizante (HL) é destacada. Detalha-se o papel do HFE na expansão do cumulus e do HL na digestão da parede folicular, permitindo a extrusão do oócito na superfície ovariana. Proveu-se um modelo não humano para explicar a digestão da parede folicular.

Cortisol induces follicle regression, while FSH prevents cortisol-induced follicle regression in pigs.

During follicular development, a few dominant follicles develop to large antral dominant follicles, whereas the remaining follicles undergo atretic degeneration. Because vascularization on the follicular surface is a morphological feature of dominant follicles, we previously classified these follicles as vascularized follicles (VFs) and non-VFs (NVFs). In NVFs, progesterone producing genes were expressed similarly to that in VFs; however, the progesterone concentration in follicular fluid was low in large NVFs. Therefore, we estimated that progesterone is converted to cortisol, which induces the loss of follicular functions. In this study, we comparative analyzed the expression of genes for progesterone converting enzymes (Cytochrome (CYP)11B1, CYP21A2, Hydroxysteroid (HSD)11B2) and cortisol receptor (NR3C1) in VF and NVF granulosa cells. In NVFs, expression of cortisol producing genes (CYP11B1 and CYP21A2) was higher than in VFs. Expression of the gene for the cortisol metabolizing enzyme HSD11B2 in NVFs was significantly lower than in VFs. In NVFs, accompanied by increasing cortisol concentration in follicular fluid, apoptosis of granulosa and cumulus cells was observed. Cultivation with FSH and metyrapone (a CYP11B1 inhibitor) of NVF cumulus-oocyte complexes inhibited apoptosis of cumulus cells and induced cumulus cell proliferation and oocyte maturation. Cortisol-induced CYP11B1 and CYP21A2 expression, whereas FSH-induced HSD11B2 mRNA expression in VF granulosa cells in the presence of cortisol. Furthermore, an addition of 18ß-glycyrrhetinic acid (18-GA; a HSD17B2 inhibitor) to cortisol and FSH-containing medium increased apoptosis of VF granulosa cells. These results suggested that cortisol is a stimulatory factor that induces follicular atresia; furthermore, inhibition of cortisol production by FSH might increase the number of healthy preovulatory follicles in pigs.

FSH directly regulates chondrocyte dedifferentiation and cartilage development.

Previous studies suggest that postmenopausal osteoarthritis is linked to a decrease in estrogen levels. However, whether follicle-stimulating hormone (FSH), the upstream hormone of estrogen, affects cartilage destruction and thus contributes to the onset of osteoarthritis has never been explored. To evaluate the potential involvement of FSH in joint degeneration and to identify the molecular mechanisms through which FSH influences chondrocytes, mouse cartilage chondrocytes and the ATDC5 chondrocyte cell line were treated with FSH and inhibitors of intracellular signaling pathways. We observed that FSH induces chondrocyte dedifferentiation by decreasing type II collagen (Coll-II) synthesis. Chondrocyte cytoskeleton reorganization was also observed after FSH treatment. The FSH-induced decrease in Coll-II was rescued by ERK-1/2 inhibition but aggravated by p38 inhibition. In addition, knocking down the FSH receptor (Fshr) by using Fshr siRNA abolished chondrocyte dedifferentiation, as indicated by the increased expression of Coll-II. Inhibition of the protein Gαi by pertussis toxin (PTX) also restored FSH-inhibited Coll-II, suggesting that Gαi is downstream of FSHR in chondrocyte dedifferentiation. FSHß antibody blockade prevented cartilage destruction and cell loss in mice. Moreover, decreased Coll-II staining due to the progression of aging could be rescued by blocking FSH. Thus, we suggest that high circulating FSH, independent of estrogen, is an important regulator in chondrocyte dedifferentiation and cartilage destruction.

Follicle-stimulating hormone promotes the proliferation of epithelial ovarian cancer cells by activating sphingosine kinase.

Follicle-stimulating hormone (FSH) is closely related to the pathogenesis and progression of epithelial ovarian cancer (EOC). However, until now, knowledge relating to FSH-driven signalling pathways that lead to the growth of EOC remained incomplete. We sought to explore whether sphingosine kinase (SphK) could mediate FSH-induced ovarian cancer cell proliferation and which pathway might be involved in this process. The expression of phospho-SphK1 and phospho-SphK2 was detected in sections of EOC tissues by Immunohistochemical staining, and clinical significances were analyzed by statistical analysis. EOC cells were treated with FSH or/and SKI-II. CCK8 assays and colony formation assays were used to investigate cell proliferation. Western blot was carried out to detect protein expression in EOC cell line after treated with FSH. Here, for the first time, we provide evidence that high expression levels of phospho-SphK1 and phospho-SphK2 were both prognostic indicators of overall survival (OS) in EOC. Additionally, the expression levels of both phospho-SphK1 and phospho-SphK2 were closely correlated with the expression level of follicle-stimulating hormone receptor (FSHR) in ovarian cancer tissues. FSH stimulated the phosphorylation of both SphK1 and SphK2 and was able to regulate the survival and growth of ovarian cancer cells by activating SphK1 and SphK2 through ERK1/2. Both isoenzymes of SphK were equally responsible for FSH-induced cell proliferation of EOC. Both Erk1/2 and Akt activation play important roles in mediating FSH-induced cell proliferation after phosphorylation of SphK. Moreover, our data demonstrated that S1P receptor 1 (S1PR1) and S1PR3, key components of the SphK signalling system, were involved in FSH-mediated proliferation of EOC. Taken together, the results of the current study revealed that SphK is an essential mediator in FSH-induced proliferation of ovarian cancer cells in EOC, which indicates a new signalling pathway that controls FSH-mediated growth in EOC and suggests a new strategy that pharmaceutically targets both isoenzymes of SphK for the management of ovarian cancer.

Follicle-stimulating hormone impairs dental pulp stem cells odontogenic differentiation.

In addition to bone, the dentin-pulp complex is also influenced by menopause, showing a decreased regenerative capacity. High levels of follicle-stimulating hormone (FSH) during menopause could directly regulate bone metabolism. Here, the role of FSH in the odontogenic differentiation of the dentin-pulp complex was investigated. Dental pulp stem cells (DPSCs) were isolated. CCK-8 assays, cell apoptosis assays, Western blotting (WB), real-time RT-PCR, alkaline phosphatase activity assays, and Alizarin Red S staining were used to clarify the effects of FSH on the proliferation, apoptosis and odontogenic differentiation of the DPSCs. MAPK pathway-related factors were explored by WB assays. FSH and its inhibitor were used in OVX rats combined with a direct pulp-capping model. HE and immunohistochemistry were used to detect reparative dentin formation and related features. The results indicated that FSH significantly decreased the odontogenic differentiation of the DPSCs without affecting cell proliferation and apoptosis. Moreover, FSH significantly activated the JNK signalling pathway, and JNK inhibitor partly rescued the inhibitory effect of FSH on DPSC differentiation. In vivo, FSH treatment attenuated the dentin bridge formation and mineralization-related protein expression in the OVX rats. Our findings indicated that FSH reduced the odontogenic capacity of the DPSCs and was involved in reparative dentinogenesis during menopause.

Mechanistic model of hormonal contraception.

Contraceptive drugs intended for family planning are used by the majority of married or in-union women in almost all regions of the world. The two most prevalent types of hormones associated with contraception are synthetic estrogens and progestins. Hormonal based contraceptives contain a dose of a synthetic progesterone (progestin) or a combination of a progestin and a synthetic estrogen. In this study we use mathematical modeling to understand better how these contraceptive paradigms prevent ovulation, special focus is on understanding how changes in dose impact hormonal cycling. To explain this phenomenon, we added two autocrine mechanisms essential to achieve contraception within our previous menstrual cycle models. This new model predicts mean daily blood concentrations of key hormones during a contraceptive state achieved by administering progestins, synthetic estrogens, or a combined treatment. Model outputs are compared with data from two clinical trials: one for a progestin only treatment and one for a combined hormonal treatment. Results show that contraception can be achieved with synthetic estrogen, with progestin, and by combining the two hormones. An advantage of the combined treatment is that a contraceptive state can be obtained at a lower dose of each hormone. The model studied here is qualitative in nature, but can be coupled with a pharmacokinetic/pharamacodynamic (PKPD) model providing the ability to fit exogenous inputs to specific bioavailability and affinity. A model of this type may allow insight into a specific drug's effects, which has potential to be useful in the pre-clinical trial stage identifying the lowest dose required to achieve contraception.

Gonadotrophins modulate cell death-related genes expression in human endometrium.

Background Gonadotrophins exert their functions by binding follicle-stimulating hormone receptor (FSHR) or luteinizing hormone and human chorionic gonadotropin receptor (LHCGR) present on endometrium. Within ovaries, FSH induces autophagy and apoptosis of granulosa cells leading to atresia of non-growing follicles, whereas hCG and LH have anti-apoptotic functions. Endometrial cells express functioning gonadotrophin receptors. The objective of this study was to analyze the effect of gonadotrophins on physiology and endometrial cells survival. Materials and methods Collected endometria were incubated for 48 or 72 h with 100 ng/mL of recombinant human FSH (rhFSH), recombinant human LH (rhLH) or highly purified hCG (HPhCG) alone or combined. Controls omitted gonadotrophins. The effect of gonadotrophins on cytochrome P450 family 11 subfamily A polypeptide 1 (CYP11A1), hypoxia inducible factor 1α (HIF1A), and cell-death-related genes expression was evaluated by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Immunohistochemistry for microtubule-associated proteins 1A/1B light chain 3B (MAP1LC3B) and apoptotic protease activating factor 1 (APAF-1) was performed. Results Gonadotrophins are able to modulate the endometrial cells survival. FSH induced autophagy and apoptosis by increasing the relative expression of MAP1LC3B and FAS receptor. In FSH-treated samples, expression of apoptosis marker APAF-1 was detected and co-localized on autophagic cells. hCG and LH does not modulate the expression of cell-death-related genes while the up-regulation of pro-proliferative epiregulin gene was observed. When combined with FSH, hCG and LH prevent autophagy and apoptosis FSH-induced. Conclusions Different gonadotrophins specifically affect endometrial cells viability differently: FSH promotes autophagy and apoptosis while LH and hCG alone or combined with rhFSH does not.

The role of FSH and LH in prostate cancer and cardiometabolic comorbidities.

INTRODUCTION: In this article we advance a potential explanation for the incidence of cardiovascular (CV) and cardiometabolic risk in patients undergoing androgen deprivation therapy (ADT) for prostate cancer. Our conceptual model involves the differential impact of gonadotropin-releasing hormone (GnRH) agonists and antagonists on the follicle-stimulating hormone (FSH) system. MATERIALS AND METHODS: Authors searched online repositories and meeting abstract databases for relevant materials. RESULTS: Mounting evidence links FSH with development and progression of prostate cancer. What is also becoming clear is that the differential effects of GnRH agonists and antagonists on FSH may at least partially explain the differing effects these agents have on CV risk during ADT. While GnRH antagonists immediately suppress FSH, GnRH agonists provoke a transient surge in FSH that may contribute to the higher CV risk observed with these agents. Additionally, recent studies suggest that GnRH antagonists may significantly reduce CV risk compared to GnRH agonists, particularly in men with pre-existing CV disease. CONCLUSIONS: Patients with cardiovascular risk factors who require ADT may benefit from the better control of FSH provided by GnRH antagonists. ADT itself appears to heighten CV risk, and data suggest that FSH may at least partly drive this risk by promoting inflammation, atherosclerosis, insulin resistance, adipocyte rearrangement and plaque instability.

Age effect on in vitro fertilization pregnancy mediated by anti-Mullerian hormone (AMH) and modified by follicle stimulating hormone (FSH).

BACKGROUND: Both follicle stimulating hormone (FSH) and anti-mullerian hormone (AMH) are widely used to assess the ovarian reserve in women for in vitro fertilization (IVF). However, studies also showed that both AMH and FSH are significantly associated with age: as age increases, AMH decreases and FSH increases. This study aims to investigate the mechanism of age effect on IVF live birth rate, particularly through mediation and interaction by AMH and FSH. METHODS: We conducted a retrospective cohort study of 13970 IVF cycles collected by eIVF from 2010 to 2016. A series of logistic mixed models were used to estimate the association of live birth and AMH (or FSH). The mediation effects and proportion mediated, were quantified by our previously proposed mediation analyses. We further investigated the FSH-modified mediation effects on live birth rate through AMH, accounting for the nonlinear age effect. RESULTS: Our analyses showed that age effect on live birth was mediated more by AMH than by FSH (18 vs. 6%). The mediation effect through AMH can be further modified by FSH level regardless of women's age. CONCLUSIONS: In summary, mediation model provides a new perspective elucidating the mechanism of IVF successful rate by age. The majority of the age effect on live birth rate remained unexplained by AMH and FSH, suggesting its importance and independent role in IVF.

Endocrine and local signaling interact to regulate spermatogenesis in zebrafish: follicle-stimulating hormone, retinoic acid and androgens.

Retinoic acid (RA) is crucial for mammalian spermatogonia differentiation, and stimulates Stra8 expression, a gene required for meiosis. Certain fish species, including zebrafish, have lost the stra8 gene. While RA still seems important for spermatogenesis in fish, it is not known which stage(s) respond to RA or whether its effects are integrated into the endocrine regulation of spermatogenesis. In zebrafish, RA promoted spermatogonia differentiation, supported androgen-stimulated meiosis, and reduced spermatocyte and spermatid apoptosis. Follicle-stimulating hormone (Fsh) stimulated RA production. Expressing a dominant-negative RA receptor variant in germ cells clearly disturbed spermatogenesis but meiosis and spermiogenesis still took place, although sperm quality was low in 6-month-old adults. This condition also activated Leydig cells. Three months later, spermatogenesis apparently had recovered, but doubling of testis weight demonstrated hypertrophy, apoptosis/DNA damage among spermatids was high and sperm quality remained low. We conclude that RA signaling is important for zebrafish spermatogenesis but is not of crucial relevance. As Fsh stimulates androgen and RA production, germ cell-mediated, RA-dependent reduction of Leydig cell activity may form a hitherto unknown intratesticular negative-feedback loop.

Localization and expression of CTRP6 in ovary and its regulation by FSH in porcine granulosa cells.

C1q/tumor necrosis factor-related protein 6 (CTRP6) is a newly identified adiponectin paralog with modulating effects on metabolism and inflammation. CTRP6 transcript is detected in human ovarian tissue. However, the expression pattern and function of CTRP6 on ovary have been rarely studied. In the present study, we preliminarily examined the structure feature and function of CTRP6 in porcine granulosa cells. The results indicated that the signaling peptide of CTRP6 was located at among positions 21 and 22, and the phosphorylation sites were at 15 (Ser), 4 (Thr) and 4 (Tyr), respectively. Meanwhile, CTRP6 was extremely homologous in livestock and chiropteran. The qPCR results showed that CTRP6 was moderately expressed in porcine follicle. Immunohistochemistry manifested that CTRP6 was presented in various types of ovarian cells. Immunofluorescence revealed that CTRP6 was located in cytoplasm in primary porcine granulosa cells. ELISA results showed that the concentration of CTRP6 in the follicular fluid was gradually decreased with the growth of antral follicle. In addition FSH increased CTRP6 expression levels in a time- and dose-dependent manner in primary porcine granulosa cells, while LH had no effect on CTRP6 basal gene expression, which suggesting CTRP6 is an FSH-responsive gene in porcine granulosa cells. Our findings imply that the CTRP6 may be a candidate gene to regulate folliculogenesis and reproductive performance.

Follicular competition in cows: the selection of dominant follicles as a synergistic effect.

The reproductive cycle of mono-ovulatory species such as cows or humans is known to show two or more waves of follicular growth and decline between two successive ovulations. Within each wave, there is one dominant follicle escorted by subordinate follicles of varying number. Under the surge of the luteinizing hormone a growing dominant follicle ovulates. Rarely the number of ovulating follicles exceeds one. In the biological literature, the change of hormonal concentrations and individually varying numbers of follicular receptors are made responsible for the selection of exactly one dominant follicle, yet a clear cause has not been identified. In this paper, we suggest a synergistic explanation based on competition, formulated by a parsimoniously defined system of ordinary differential equations (ODEs) that quantifies the time evolution of multiple follicles and their competitive interaction during one wave. Not discriminating between follicles, growth and decline are given by fixed rates. Competition is introduced via a growth-suppressing term, equally supported by all follicles. We prove that the number of dominant follicles is determined exclusively by the ratio of follicular growth and competition. This number turns out to be independent of the number of subordinate follicles. The asymptotic behavior of the corresponding dynamical system is investigated rigorously, where we demonstrate that the [Formula: see text]-limit set only contains fixed points. When also including follicular decline, our ODEs perfectly resemble ultrasound data of bovine follicles. Implications for the involved but not explicitly modeled hormones are discussed.

Electrophysiological Responses to Different Follicle-Stimulating Hormone Isoforms on Human Cumulus Oophorus Cells: Preliminary Results.

OBJECTIVE: The aim of the present study was to provide a better understanding of the specific action of two follicle-stimulating hormone (FSH) isoforms (ß-follitropin and sheep FSH) on the membrane potential of human cumulus cells. METHODS: Electrophysiological data were associated with the characteristics of the patient, such as age and cause of infertility. The membrane potential of cumulus cells was recorded with borosilicate microelectrodes filled with KCl (3 M) with tip resistance of 15 to 25 MΩ. Sheep FSH and ß-follitropin were topically administered onto the cells after stabilization of the resting potential for at least 5 minutes. RESULTS: In cumulus cells, the mean resting membrane potential was - 34.02 ± 2.04 mV (n = 14). The mean membrane resistance was 16.5 ± 1.8 MΩ (n = 14). Sheep FSH (4 mUI/mL) and ß-follitropin (4 mUI/mL) produced depolarization in the membrane potential 180 and 120 seconds after the administration of the hormone, respectively. CONCLUSION: Both FSH isoforms induced similar depolarization patterns, but ß-follitropin presented a faster response. A better understanding of the differences of the effects of FSH isoforms on cell membrane potential shall contribute to improve the use of gonadotrophins in fertility treatments.

OBJETIVO: O objetivo do presente estudo foi fornecer uma melhor compreensão da ação específica de duas isoformas de hormônio folículo estimulante (FSH, sigla em inglês) (ß-folitropina e FSH ovino) no potencial de membrana de células do cumulus oophorus humanas. MéTODOS: Dados eletrofisiológicos foram associados às características da paciente, como idade e causa da infertilidade. O potencial de membrana das células do cumulus foi registrado com microeletrodos de borossilicato preenchidos com KCl (3 M) com uma resistência de 15 a 25 MΩ. O FSH ovino e a ß-folitropina foram administrados topicamente nas células após a estabilização do potencial de repouso durante pelo menos 5 minutos. RESULTADOS: Nas células do cumulus, o potencial médio de membrana em repouso foi de -34,02 ± 2,04 mV (n = 14). A resistência média da membrana foi de 16,5 ± 1,8 MΩ (n = 14). O FSH ovino (4 mUI/mL) e a ß-folitropina (4 mUI/mL) produziram despolarização no potencial de membrana 180 e 120 segundos após a aplicação do hormônio, respectivamente. CONCLUSãO: Ambas as isoformas de FSH induzem padrões de despolarização semelhantes, mas a ß-folitropina apresentou uma resposta mais rápida. Uma melhor compreensão das diferenças dos efeitos das isoformas do FSH no potencial da membrana celular contribuirá para aprimorar o uso das gonadotrofinas no estímulo ovariano controlado e em protocolos de maturação oocitária in vitro.

Electrophysiological responses to different follicle-stimulating hormone isoforms on human cumulus oophorus cells: preliminary results / Respostas eletrofisiológicas a diferentes isoformas de FSH em células humanas do cumulus oophorus: resultados preliminares

Abstract Objective The aim of the present study was to provide a better understanding of the specific action of two follicle-stimulating hormone (FSH) isoforms (β-follitropin and sheep FSH) on the membrane potential of human cumulus cells. Methods Electrophysiological data were associated with the characteristics of the patient, such as age and cause of infertility. The membrane potential of cumulus cells was recorded with borosilicate microelectrodes filled with KCl (3 M) with tip resistance of 15 to 25 MΩ. Sheep FSH and β-follitropin were topically administered onto the cells after stabilization of the resting potential for at least 5 minutes. Results In cumulus cells, the mean resting membrane potential was - 34.02 ± 2.04 mV (n = 14). The mean membrane resistance was 16.5 ± 1.8 MΩ (n = 14). Sheep FSH (4 mUI/mL) and β-follitropin (4 mUI/mL) produced depolarization in the membrane potential 180 and 120 seconds after the administration of the hormone, respectively. Conclusion Both FSH isoforms induced similar depolarization patterns, but β-follitropin presented a faster response. A better understanding of the differences of the effects of FSH isoforms on cell membrane potential shall contribute to improve the use of gonadotrophins in fertility treatments.

Resumo Objetivo O objetivo do presente estudo foi fornecer uma melhor compreensão da ação específica de duas isoformas de hormônio folículo estimulante (FSH, sigla em inglês) (β-folitropina e FSH ovino) no potencial de membrana de células do cumulus oophorus humanas. Métodos Dados eletrofisiológicos foram associados às características da paciente, como idade e causa da infertilidade. O potencial de membrana das células do cumulus foi registrado com microeletrodos de borossilicato preenchidos com KCl (3 M) com uma resistência de 15 a 25 MΩ. O FSH ovino e a β-folitropina foram administrados topicamente nas células após a estabilização do potencial de repouso durante pelo menos 5 minutos. Resultados Nas células do cumulus, o potencial médio de membrana em repouso foi de -34,02 ± 2,04 mV (n = 14). A resistência média da membrana foi de 16,5 ± 1,8 MΩ (n = 14). O FSH ovino (4 mUI/mL) e a β-folitropina (4 mUI/mL) produziram despolarização no potencial de membrana 180 e 120 segundos após a aplicação do hormônio, respectivamente. Conclusão Ambas as isoformas de FSH induzem padrões de despolarização semelhantes, mas a β-folitropina apresentou uma resposta mais rápida. Uma melhor compreensão das diferenças dos efeitos das isoformas do FSH no potencial da membrana celular contribuirá para aprimorar o uso das gonadotrofinas no estímulo ovariano controlado e em protocolos de maturação oocitária in vitro.

FSH Actions and Pregnancy: Looking Beyond Ovarian FSH Receptors.

By mediating estrogen synthesis and follicular growth in response to FSH, the ovarian FSH receptor (FSHR) is essential for female fertility. Indeed, ovarian stimulation via administration of FSH to women with infertility is part of the primary therapeutic intervention used in assisted reproductive technology. In physiological and therapeutic contexts, current dogma dictates that once ovulation has occurred, FSH/FSHR signaling is no longer required for successful pregnancy outcomes. However, a continued role for FSH during pregnancy is suggested by recent studies demonstrating extraovarian FSHR in the female reproductive tract. Furthermore, functional roles for FSHR in placenta and in uterine myometrium have now been demonstrated. In placenta, vascular endothelial FSHR of fetal vessels within the chorionic villi (human) or labyrinth (mouse) mediate angiogenesis, and it has further been shown that deletion of placental Fshr in mice has deleterious effects on pregnancy. In uterine myometrium, changes in the densities of FSHR in muscle fiber and stroma in the nonpregnant state, early pregnancy, and term pregnancy differentially regulate contractile activity, suggesting that signaling through myometrial FSHR may contribute to the quieting of contractile activity required for successful implantation and that the temporal upregulation of the FSHR at term pregnancy may be required for the appropriate timing of parturition. In addition, extraovarian expression of mRNAs encoding the glycoprotein hormone α subunit and the FSH ß subunit has been demonstrated, suggesting that these novel aspects of extraovarian FSH/FSHR signaling during pregnancy may be mediated by locally synthesized FSH.