Inadequate detection of the FSHR complicates future research on extragonadal FSHR localization

INTRODUCTION

Recently, follicle stimulating hormone (FSH) through interaction with its receptor (FSHR) has been proposed to play a role in postmenopausal osteoporosis and cardiovascular disease, rather than the loss of estrogen. To explore this hypothesis, unravelling which cells express extragonadal FSHR on protein level is key.

METHODS

We used two commercial anti-FSHR antibodies and validated them by performing immunohistochemistry on positive (ovary, testis) and negative controls (skin).

RESULTS

The monoclonal anti-FSHR antibody could not identify the FSHR in ovary or testis. The polyclonal anti-FSHR antibody stained the granulosa cells (ovary) and Sertoli cells (testis), yet there was equally intense staining of other cells/extracellular matrix. Furthermore, the polyclonal anti-FSHR antibody also stained skin tissue extensively, suggesting that the antibody stains more than just FSHR.

DISCUSSION

The findings in this study may add accuracy to literature on extragonadal FSHR localization and warrants attention to the use of inadequate anti-FSHR antibodies to value the potential role of FSH/FSHR in postmenopausal disease.

Follicle-Stimulating Hormone Glycosylation Variants Distinctly Modulate Pre-antral Follicle Growth and Survival

Follicle-stimulating hormone (FSH) is a key endocrine regulator of ovarian function. FSH is secreted as 2 macroglycosylation variants: partially glycosylated FSH (FSH21/18) and fully glycosylated FSH (FSH24). FSH21/18 is more potent than FSH24 at binding to and activating the FSH receptor (R). The ratio of FSH21/18:FSH24 has been shown to change with age, with FSH21/18 predominant at reproductive prime, and FSH24 predominant during perimenopause/menopause. How these FSH glycosylation variants modulate ovarian follicle functions remains largely unknown. The aim of this study was to investigate the effect of FSH glycosylation variants of pre-antral follicle function. Pre-antral follicles were isolated from 3- to 5-week-old C57BL/6 mice and treated ±10 ng/mL FSH21/18, FSH24, a ratio of 80:20 FSH21/18:FSH24 (to mimic reproductive prime), 50:50 FSH21/18:FSH24 (perimenopause), or 20:80 FSH21/18:FSH24 (menopause) for up to 96 hours. FSH21/18 and 80:20 FSH21/18:FSH24 increased follicle growth, in comparison with control, contrasting with FSH24 and 20:80 FSH21/18:FSH24. Survival rates were decreased in follicles treated with FSH24 or 20:80 FSH21/18:FSH24, with follicles undergoing basement membrane rupture and oocyte extrusion, increased Caspase3 gene and protein expression, and decreased markers of cell proliferation in FSH24 or 20:80 FSH21/18:FSH24-treated follicles. Moreover, this correlated with differential regulation of key genes modulating follicular functions. Pharmacological inhibitors of key FSH signal pathways suggests FSH21/18 and FSH24 initiate different FSHR signal pathway activation, which may determine their differential effects on follicle growth and survival. These data suggest that the nature of FSH glycosylation modulates the follicular cellular environment to regulate follicle growth and survival and may underpin the increasing ovarian resistance to FSH observed during aging.

[Effects of nutritional preparation on HPO axis function and energy metabolism in uterus and ovary of rats exposed to intermittent cold]

Objective: To investigate the effects of a self-designed nutritional preparation on hypothalamic-pituitary-ovarian (HPO) axis function and energy metabolism in female SD rats exposed to intermittent cold. Methods: Female SD rats were divided into control group, cold exposure group and nutritional preparation group. The control group and cold exposure group were given distilled water by daily gavage, and the nutritional preparation group was given nutritional preparation intragastrically. After the treatment, the cold exposure group and nutritional preparation group were exposed to -10℃ in a cabin for 4 h every day. After being treated for 14 days, the serum, uterus and ovary of rats were collected. The serum follicle stimulating hormone (FSH), luteinizing hormone (LH) and other hormone indicators were detected by enzyme-linked immunosorbent assay (ELISA) and colorimetry was used to detect ATPase and other energy metabolism related indicators. Results: Compared with the control group, cold exposure significantly up-regulated the protein expressions of FSHR and LHR, and notably enhanced the activity of Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase in ovary and uterus (P<0.05). Nutritional preparation down-regulated the protein expressions of FSHR and LHR, and inhibited the activity of ATPase in ovary and uterus (P<0.05) compared with the cold exposure group. Conclusion: Nutritional preparations can effectively improve the expressions of HPO axis related receptors and abnormal energy metabolism in uterus and ovary caused by intermittent cold exposure.

Mechanistic insight into how gonadotropin hormone receptor complexes direct signaling†

Gonadotropin hormones and their receptors play a central role in the control of male and female reproduction. In recent years, there has been growing evidence surrounding the complexity of gonadotropin hormone/receptor signaling, with it increasingly apparent that the Gαs/cAMP/PKA pathway is not the sole signaling pathway that confers their biological actions. Here we review recent literature on the different receptor-receptor, receptor-scaffold, and receptor-signaling molecule complexes formed and how these modulate and direct gonadotropin hormone-dependent intracellular signal activation. We will touch upon the more controversial issue of extragonadal expression of FSHR and the differential signal pathways activated in these tissues, and lastly, highlight the open questions surrounding the role these gonadotropin hormone receptor complexes and how this will shape future research directions.

Association of single-nucleotide polymorphisms in the ESR2 and FSHR genes with poor ovarian response in infertile Jordanian women

Objective

Poor ovarian response (POR) refers to a subnormal follicular response that leads to a decrease in the quality and quantity of the eggs retrieved after ovarian stimulation during assisted reproductive treatment (ART). The present study investigated the associations of multiple variants of the estrogen receptor 2 (ESR2) and follicle-stimulating hormone receptor (FSHR) genes with POR in infertile Jordanian women undergoing ART.

Methods

Four polymorphisms, namely ESR2 rs1256049, ESR2 rs4986938, FSHR rs6165, and FSHR rs6166, were investigated in 60 infertile Jordanian women undergoing ART (the case group) and 60 age-matched fertile women (the control group), with a mean age of 33.60±6.34 years. Single-nucleotide polymorphisms (SNPs) were detected by restriction fragment length polymorphism and then validated using Sanger sequencing.

Results

The p-value of the difference between the case and control groups regarding FSHR rs6166 was very close to 0.05 (p=0.054). However, no significant differences were observed between the two groups in terms of the other three SNPs, namely ESR2 rs1256049, ESR2 rs4986938, and FSHR rs6165 (p=0.561, p=0.433, and p=0.696, respectively).

Conclusion

The association between FSHR rs6166 and POR was not statistically meaningful in the present study, but the near-significant result of this experiment suggests that statistical significance might be found in a future study with a larger number of patients.

Receptor Binding Inhibitor Suppresses Carcinogenesis of Cervical Cancer by Depressing Levels of FSHR and ERβ in Mice

BACKGROUND

FSH Receptor Binding Inhibitor (FRBI) blocked the binding of FSH to FSHR. Our initial study revealed FRBI reduced the maturation rate, enhanced the apoptosis of sheep Cumulus-Oocyte Complex (COCs). Little is known about whether FRBI modulates ERβ and FSHR levels in the normal uterine and cancerous tissues. The present study aimed to evaluate the FRBI effects on the expressions of Estrogen Receptor-beta (ERβ) and FSH receptor (FSHR) in the uteri.

METHODS

150 mice were assigned to FRBI+FSH (COM), FSH and control groups (CG). Mice of COM-1, COM-2 and COM-3 groups were simultaneously intramuscularly injected with 500, 750 and 1000 µg FRBI with 10 IU FSH, respectively for five days. Western blotting and qPCR were utilized to determine the expression of ERβ and FSHR.

RESULTS

In comparison with FSH group, uterine lumen and glands of COM groups became narrow. The uterine wall and endometrial epithelium were thinned, and uterine lumen became narrow. Epithelial cells were decreased. Uterine wall thicknesses of COM-1, COM-2 and COM-3 groups were reduced by 6.49%, 14.89% and 15.69% on day 30 as compared with FSH group. Uterine perimetrium thicknesses of COM-1, COM-2 and COM-3 groups were reduced by 16.17%, 17.93% and 19.92% on day 20 in comparison with FSH group. Levels of FSHR mRNAs and proteins of COM-1, COM-2 and COM-3 groups were less than FSH group on days 20 and 30 (P<0.05). ERβ protein of COM-3 group was less than FSH group. Serum estradiol (E2) and FSH concentrations of COM-2 and COM-3 were lower than that of FSH group on day 30.

CONCLUSION

FRBI could decrease UWT and UPT, also block the uterine development, decline expression levels of ERβ and FSHR protein. Additionally, FRBI reduced the secretion of secretion of FSH and E2. Downregulating expression of FSHR and ERβ may be a potential treatment regimen for cervical cancer patients.

Expression of follicle stimulating hormone receptors in intra-tumoral vasculature and in tumoral cells - the involvement in tumour progression and the perspectives of application in cancer diagnosis and therapy

In normal conditions follicle stimulating hormone receptors (FSHR) are expressed in zona granulosa cells of the ovary and Sertoli cells of the testis. However, the ectopic expression of FSHR was recently discovered in intra-tumoral blood vessels endothelia and/or in tumoral cells of many extra-gonadal human tumors (particularly in endocrine tumours). The paper reviews the data concerning the appearance of ectopic FSHR in particular human neoplasms. The possible involvement of FSHR in tumor progression and the use of FSHR examination for diagnostic purposes is also reviewed. Finally, the putative role of FSHR as a new target in oncological therapy is also discussed.

Ginsenoside Rg1 improves fertility and reduces ovarian pathological damages in premature ovarian failure model of mice

This study aims to investigate the effect as well as mechanism of ginsenoside Rg1 (Rg1) on premature ovarian failure (POF) induced by d-galactose (d-gal) in mice. C57BL/6 female mice were divided into four groups randomly, which were the saline group, the d-gal group, the d-gal + Rg1 group, and the Rg1 group. Body weight was recorded. Overall ovarian function including estrous cycles, sex hormone secretion, ovarian follicle development, and ovarian morphology was analyzed by H&E staining and ELISA. Effect of Rg1 on aging was determined by analyzing the activities of oxidation-associated biomarkers, pro-inflammatory cytokine secretion, expression of senescence-associated proteins, and fertility. Compared with the d-gal group, in Rg1 + d-gal group, body weight was increased significantly, estrous cycle block was released, and fertility and the morphology of ovaries were restored. And, Rg1 treatment after d-gal administration significantly reduced senescence-associated protein expression, increased the activity of total superoxide dismutase and glutathione peroxidase from bovine erythrocyte, and induced higher follicle stimulating hormone receptor protein expression. Additionally, the expression levels of malondialdehyde, interleukin-1β, tumor necrosis factor-α, and interleukin-6 were significantly decreased. Together, Rg1 improves mouse fertility and reduces ovarian pathological damage in d-gal-induced POF model possibly through enhancing anti-inflammatory and antioxidant capacities and reducing expression of senescence signal pathway proteins. Impact statement Ginsenoside Rg1 (Rg1) is a kind of natural estrogen and it has antioxidation and antiaging effects. However, whether Rg1 has effects on premature ovarian failure (POF) is still not clear. In this study, aging model induced by d-galactose was used to mimic POF. The effect and possible mechanism of Rg1 on ovary aging was investigated. We found that Rg1 treatment up-regulated the expression of follicle stimulating hormone receptor and down-regulated senescence-associated protein expression in granule cells of POF mice. Particularly, Rg1 improved fertility ability and reduced ovarian pathological damages by its antioxidative and anti-inflammation capacity. Thus, Rg1 enhances the antiaging ability of ovary and fertility ability of POF mice through enhancing the anti-inflammatory and antioxidant capacities of ovary.

FSH stimulates ovarian cancer cell growth by action on growth factor variant receptor

A number of FSH receptor (FSH-R) isoforms with distinct structural motifs and signaling paradigms have been described, including a single transmembrane domain variant that functions as a growth factor type receptor (FSH-R3). This study tested the hypothesis that FSH can stimulate ovarian cancer cell proliferation by acting on FSH-R3, using the tumorigenic mouse ovarian surface epithelial cell (MOSEC) line ID8. FSH enhanced ID8 proliferation in a concentration-dependent fashion. Moreover, FSH-treatment of ID8 elicited intracellular events consistent with activation of FSH-R3 and distinct from those associated with activation of the canonical G-protein coupled FSH-R isoform (FSH-R1). Specifically, the FSH-R3 signaling pathway included cAMP-independent activation of ERK downstream of an SNX-482 sensitive component likely to be the Cav2.3 calcium channel. Northern analysis using probes specific for exons 7 and 11 of FSH-R identified consistently only one 1.9kb transcript. Immunoblot analysis confirmed expression of FSH-R3 but not FSHR-1 in ID8. Together, these data suggest that FSH-R3 signaling promotes proliferation of ovarian cancer cells.