Roles for transforming growth factor beta superfamily proteins in early folliculogenesis

Understanding the Mechanisms of Diminished Ovarian Reserve: Insights from Genetic Variants and Regulatory Factors

Delaying childbearing age has become a trend in modern times, but it has also led to a common challenge in clinical reproductive medicine-diminished ovarian reserve (DOR). Since the mechanism behind DOR is unknown and its clinical features are complex, physicians find it difficult to provide targeted treatment. Many factors affect ovarian reserve function, and existing studies have shown that genetic variants, upstream regulatory genes, and changes in protein expression levels are present in populations with reduced ovarian reserve function. However, existing therapeutic regimens often do not target the genetic profile for more individualized treatment. In this paper, we review the types of genetic variants, mutations, altered expression levels of microRNAs, and other related factors and their effects on the regulation of follicular development, as well as altered DNA methylation. We hope this review will have significant implications for the future treatment of individuals with reduced ovarian reserve.

A cross talk study on sitagliptin mediated reclamation on TGF β signalling, DPP 4, miR-29a and miR-24 expression in PCOS rats fed with high fat-high fructose diet

Polycystic Ovary Syndrome (PCOS) is a multifactorial reproductive, endocrine and metabolic disturbance which is very commonly observed in females of reproductive age group. The disease is still incurable however the use of synthetic drugs in combination with lifestyle is recommended. Accordingly, the present study was conducted to investigate the possible beneficial effects of sitagliptin on PCOS induced rats on control diet (CD)/high fat- high fructose diet (HFFD). PCOS was induced by giving testosterone propionate (TP) for 28 days to both the CD/HFFD rats and treated with STG i.p. for last 15 days. At the end of the experiment lipid profile, inflammatory markers, expression of NF-κB-p65, miR-24 and miR-29a, fibrotic and apoptotic proteins from ovary tissue were examined. Moreover, lipid accumulation and fibrosis of ovary tissue was further confirmed using Sudan III and Masson's trichrome stain. STG treated rats exerted a significant decrease in levels of cholesterol, TG, LDL-C, VLDL-C, IL-6 and TNF-α and increased HDL-C level, miR-24 and miR-29a expression. STG treated groups expressed significantly decreased expression of NF-κB-p65, TGF-β1, p-Smad 2 and p-Smad 3 followed by no significant changes in the expression of BAX, caspase-9, caspase-3 and Bcl-2 in all the PCOS induced groups. Among all the CD/ HFFD fed groups, rats on HFFD showed more devastating effect which suggests that diet plays a major role in genesis of PCOS. In conclusion, current results reflect the potential impact of STG against dyslipidaemia, inflammation and fibrosis in PCOS rats via regulating dyslipidaemia and fibrosis via DPP 4 mediated miR-29a expression.

Long noncoding RNA BMPR1B-AS1 stability regulated by IGF2BP2 affects the decidualization in endometriosis patients through the SMAD1/5/9 pathway

Endometriosis (EMs)-related infertility commonly has decreased endometrial receptivity and normal decidualization is the basis for establishing and maintaining endometrial receptivity. However, the potential molecular regulatory mechanisms of impaired endometrial decidualization in patients with EMs have not been fully clarified. We confirmed the existence of reduced endometrial receptivity in patients with EMs by scanning electron microscopy and quantitative real-time PCR. Here we identified an lncRNA, named BMPR1B-AS1, which is significantly downregulated in eutopic endometrium in EMs patients and plays an essential role in decidual formation. Furthermore, RNA pull-down, mass spectrometry, RNA immunoprecipitation, and rescue analyses revealed that BMPR1B-AS1 positively regulates decidual formation through interaction with the RNA-binding protein insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2). Downregulation of IGF2BP2 led to a decreased stability of BMPR1B-AS1 and inhibition of activation of the SMAD1/5/9 pathway, an inhibitory effect which diminished decidualization in human endometrial stromal cells (hESCs) decidualization. In conclusion, our identified a novel regulatory mechanism in which the IGF2BP2-BMPR1B-AS1-SMAD1/5/9 axis plays a key role in the regulation of decidualization, providing insights into the potential link between abnormal decidualization and infertility in patients with EMs, which will be of clinical significance for the management and treatment of infertility in patients with EMs.

Comparing GDF9 in mature follicles and clinical outcomes across different PCOS phenotype

Background

Polycystic ovary syndrome (PCOS) is main cause of anovulatory infertility in women with gestational age. There are currently four distinct phenotypes associated with individualized endocrinology and metabolism. Growth differentiation factor 9 (GDF9) is a candidate as potential biomarker for the assessment of oocyte competence. The effect on oocyte capacity has not been evaluated and analyzed in PCOS phenotypes.

Objective

We aimed to screen the expression levels of GDF9 in mature follicles of women with controlled ovarian hyperstimulation (COS) with different PCOS phenotypes. To determine the correlation between the expression level of GDF9 and oocyte development ability.

Methods

In Part 1, we conducted a retrospective study comparing the clinical outcomes and endocrine characteristics of patients with PCOS according to different subgroups (depending on the presence or absence of the main features of polycystic ovarian morphology (PCOM), hyperandrogenism (HA), and oligo-anovulation (OA)) and non-PCOS control group. We stratified PCOS as phenotype A (n = 29), phenotype B (n = 18) and phenotype D (n = 24). In Part 2, the expression of GDF9 in follicular fluid (FF) and cumulus cells (CCs) were detected by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry, respectively.

Results

In Part 1, the baseline clinical, hormonal, and ultrasonographic characteristics of the study population were matched with the presence or absence of the cardinal features of each PCOS phenotypes showed a clear difference. Phenotypes A and D had statistically significant associations with blastocyst formation and clinical pregnancy compared with phenotypes B (p < 0.001). In Part 2, the levels of GDF9 in FF and CCs for phenotype A and B were significantly were higher than those of phenotype D (P = 0.019, P = 0.0015, respectively). Multivariate logistic regression analysis showed that GDF9 was an important independent predictor of blastocyst formation (P＜0.001). The blastocyst formation rate of phenotype A was higher than that of phenotype B and D (P＜0.001). Combining the results of the two parts, GDF9 appears to play a powerful role in the development of embryos into blastocysts.

Conclusions

GDF9 expression varies with different PCOS phenotypes. Phenotype A had higher GDF9 levels and blastocyst formation ability.

Comparative transcriptomic analysis of the different developmental stages of ovary in the cuttlefish Sepia pharaonis

The cuttlefish, Sepia pharaonis, is characterized by rapid growth and strong disease resistance, making it an important commercially farmed cephalopod species in the southeastern coastal regions of China. However, in the reproductive process of S. pharaonis, there are challenges such as a low output of eggs, poor quality, and low survival rates of newly hatched juveniles. Therefore, there is an urgent need to study the molecular mechanisms underlying ovarian development in this species. In this study, we conducted the first transcriptomic analysis of the ovary at four developmental stages: the undeveloped stage, developing stage, nearly-ripe stage, and ripe stage, and compared the transcriptomics among these four stages using Illumina sequencing technology. The total numbers of clean reads of the four stages ranged from 40,890,772 to 52,055,714 reads. A total of 136,829 DEGs were obtained, GC base ratios of raw data were between 38.44 and 44.59%, and the number of uniquely mapped reads spanned from 88.08 to 95.90%. The Pearson correlation coefficient demonstrated a strong correlation among different samples within the same group, PCA and Anosim analysis also revealed that the grouping of these four stages was feasible, and each stage could be distinguished from the others. GO enrichment analysis demonstrated that ovarian follicle growth, sex differentiation, and transforming growth factor beta receptor, played a foreshadowing role at the early ovarian development stage, and the terms of small molecule metabolic process, peptide metabolic process, and catalytic activity were prominent at the mature stage. Meanwhile, KEGG analysis showed that the early ovarian development of S. pharaonis was mainly associated with the cell cycle, DNA replication, and carbon metabolism, while the mid-late ovarian development was involved with the signal transduction, endocrine system, and reproduction pathway. RT-qPCR further confirmed the consistent expression patterns of genes such as 17β-HSD, GH, VGS, NFR, and NYR in the ovaries of S. pharaonis, exhibiting elevated levels of expression during the maturation stage. Conversely, ER and OM exhibited high expression levels during the early stages of ovarian development. These transcriptomic data provide insights into the molecular mechanisms of S. pharaonis ovarian development. The findings of this study will contribute to improving the reproduction and development of cuttlefish and enriching the bioinformatics knowledge of cephalopods.

SMAD signaling pathway is disrupted by BPA via the AMH receptor in bovine granulosa cells†

Significant events that determine oocyte competence occur during follicular growth and oocyte maturation. The anti-Mullerian hormone, a positive predictor of fertility, has been shown to be affected by exposure to endocrine disrupting compounds, such as bisphenol A and S. However, the interaction between bisphenols and SMAD proteins, mediators of the anti-Mullerian hormone pathway, has not yet been elucidated. AMH receptor (AMHRII) and downstream SMAD expression was investigated in bovine granulosa cells treated with bisphenol A, bisphenol S, and then competitively with the anti-Mullerian hormone. Here, we show that 24-h bisphenol A exposure in granulosa cells significantly increased SMAD1, SMAD4, and SMAD5 mRNA expression. No significant changes were observed in AMHRII or SMADs protein expression after 24-h treatment. Following 12-h treatments with bisphenol A (alone or with the anti-Mullerian hormone), a significant increase in SMAD1 and SMAD4 mRNA expression was observed, while a significant decrease in SMAD1 and phosphorylated SMAD1 was detected at the protein level. To establish a functional link between bisphenols and the anti-Mullerian hormone signaling pathway, antisense oligonucleotides were utilized to suppress AMHRII expression with or without bisphenol exposure. Initially, transfection conditions were optimized and validated with a 70% knockdown achieved. Our findings show that bisphenol S exerts its effects independently of the anti-Mullerian hormone receptor, while bisphenol A may act directly through the anti-Mullerian hormone signaling pathway providing a potential mechanism by which bisphenols may exert their actions to disrupt follicular development and decrease oocyte competence.

Rescue of bmp15 deficiency in zebrafish by mutation of inha reveals mechanisms of BMP15 regulation of folliculogenesis

As an oocyte-specific growth factor, bone morphogenetic protein 15 (BMP15) plays a critical role in controlling folliculogenesis. However, the mechanism of BMP15 action remains elusive. Using zebrafish as the model, we created a bmp15 mutant using CRISPR/Cas9 and demonstrated that bmp15 deficiency caused a significant delay in follicle activation and puberty onset followed by a complete arrest of follicle development at previtellogenic (PV) stage without yolk accumulation. The mutant females eventually underwent female-to-male sex reversal to become functional males, which was accompanied by a series of changes in secondary sexual characteristics. Interestingly, the blockade of folliculogenesis and sex reversal in bmp15 mutant could be partially rescued by the loss of inhibin (inha-/-). The follicles of double mutant (bmp15-/-;inha-/-) could progress to mid-vitellogenic (MV) stage with yolk accumulation and the fish maintained their femaleness without sex reversal. Transcriptome analysis revealed up-regulation of pathways related to TGF-β signaling and endocytosis in the double mutant follicles. Interestingly, the expression of inhibin/activin βAa subunit (inhbaa) increased significantly in the double mutant ovary. Further knockout of inhbaa in the triple mutant (bmp15-/-;inha-/-;inhbaa-/-) resulted in the loss of yolk granules again. The serum levels of estradiol (E2) and vitellogenin (Vtg) both decreased significantly in bmp15 single mutant females (bmp15-/-), returned to normal in the double mutant (bmp15-/-;inha-/-), but reduced again significantly in the triple mutant (bmp15-/-;inha-/-;inhbaa-/-). E2 treatment could rescue the arrested follicles in bmp15-/-, and fadrozole (a nonsteroidal aromatase inhibitor) treatment blocked yolk accumulation in bmp15-/-;inha-/- fish. The loss of inhbaa also caused a reduction of Vtg receptor-like molecules (e.g., lrp1ab and lrp2a). In summary, the present study provided comprehensive genetic evidence that Bmp15 acts together with the activin-inhibin system in the follicle to control E2 production from the follicle, Vtg biosynthesis in the liver and its uptake by the developing oocytes.

Evidence for the expression of vasorin in the human female reproductive tissues

Objective: To investigate the expression and localization of Vasorin (Vasn) in human female reproductive system. Methods: The presence of Vasorin was evaluated by RT-PCR and immunoblotting analyses in patient-derived endometrial, myometrial and granulosa cells (GCs) primary cultures. Immunostaining analyses were performed to detect Vasn localization in primary cultures and in ovarian and uterine tissues. Results: Vasn mRNA was detected in patient-derived endometrial, myometrial and GCs primary cultures without significant differences at the transcript level. Otherwise, immunoblotting analysis showed that Vasn protein levels were significantly higher in GCs than proliferative endometrial stromal cells (ESCs) and myometrial cells. Immunohistochemistry performed in ovarian tissues revealed that Vasn was expressed in the GCs of ovarian follicles at different stages of development with a higher immunostaining signal in mature ovarian follicles such as the antral follicle or on the surface of cumulus oophorus cells than in early-stage follicles. The immunostaining of uterine tissues showed that Vasn was expressed in the proliferative stroma endometrium while it was significantly less expressed in the secretory endometrium. Conversely, no protein immunoreactivity was revealed in health myometrial tissue. Conclusions: Our results revealed the presence of Vasn in the ovary and the endometrium. The pattern of Vasn expression and distribution suggests that this protein may have a role in the regulation of processes such as folliculogenesis, oocyte maturation, and endometrial proliferation.

Lyophilized equine platelet-rich plasma (L-GFequina) antagonize the Reproductive toxicity and oxidative stress Induced by Cyclophosphamide in female rats

BACKGROUND

The antineoplastic agent Cyclophosphamide (CP) induces reproductive toxicity. New strategies for protecting ovarian tissue damage in women with chemotherapy-induced reproductive toxicity are essential. This study was designed to evaluate the possible protective effect of combined treatment with L-GF^equina on CP-induced reproductive toxicity in the mature female rat.

METHODOLOGY

Forty mature female rats were assigned into four groups: First group, control: rats were intraperitoneally injected (IP) with 200 µl sterile saline solution on days 1 and 10; Group 2 (CP): were IP injected with 75 mg/kg on days 1 and 10 to induce POI); Group 3 (CP + L-GF^equina): as in group 2 + IP injected with 200 µl rehydrated L-GF^equina half-hour after CP injection on day 1 and 10); Group 4 (L-GF^equina): rats were IP injected with 200 µl L-GF^equina on day 1 and 10). Blood samples were collected for a complete blood picture and determinations of nitric oxide and malondialdehyde. Animals were sacrificed on Day-21, and genitalia was dissected, weighed, and fixed in 10% formalin for histopathological and morphometric evaluation.

RESULTS

On day 21 of the experiment, body weight, ovarian parameters (Ovarian weight, uterine weight, the number of ovarian follicles, and corpora lutea (CL) were determined, and histopathological changes, blood profile, as well as antioxidant activity assessment, were performed. CP significantly suppresses ovarian and uterine functions and increased MAD, NO levels, RBCs, hemoglobin, WBCs, and platelet count compared to the control group ( P < 0.05). While, in CP + L-GF^equina group, gross, histomorphometry parameters, blood, and biochemical markers were similar to that in the control. IP injection of L-GF^equina alone significantly (P < 0.05) increased body weight, and ovarian and uterine morphometry compared with the control.

CONCLUSION

co-administration of L-GF^equina with CP might protect the reproductive organs in rats through its high antioxidant capacity.

Inactivation of growth differentiation factor 9 blocks folliculogenesis in pigs†

Growth differentiation factor 9 (GDF9) is a secreted protein belonging to the transforming growth factor beta superfamily and has been well characterized for its role during folliculogenesis in the ovary. Although previous studies in mice and sheep have shown that mutations in GDF9 disrupt follicular progression, the exact role of GDF9 in pigs has yet to be elucidated. The objective of this study was to understand the role of GDF9 in ovarian function by rapidly generating GDF9 knockout (GDF9-/-) pigs by using the CRISPR/Cas9 system. Three single-guide RNAs designed to disrupt porcine GDF9 were injected with Cas9 mRNA into zygotes, and blastocyst-stage embryos were transferred into surrogates. One pregnancy was sacrificed on day 100 of gestation to investigate the role of GDF9 during oogenesis. Four female fetuses were recovered with one predicted to be GDF9-/- and the others with in-frame mutations. All four had fully formed oocytes within primordial follicles, confirming that knockout of GDF9 does not disrupt oogenesis. Four GDF9 mutant gilts were generated and were grown past puberty. One gilt was predicted to completely lack functional GDF9 (GDF9-/-), and the gilt never demonstrated standing estrus and had a severely underdeveloped reproductive tract with large ovarian cysts. Further examination revealed that the follicles from the GDF9-/- gilt did not progress past preantral stages, and the uterine vasculature was less extensive than the control pigs. By using the CRISPR/Cas9 system, we demonstrated that GDF9 is a critical growth factor for proper ovarian development and function in pigs.

Efficacy and Clinical Significance of the Zuogui Pill on Premature Ovarian Failure via the GDF-9/Smad2 Pathway

Our study aims to investigate the efficacy and clinical significance of the Zuogui pill (ZGP) on premature ovarian failure (POF) via the GDF-9/Smad2 pathway. Changes in clinical symptoms in the control group (treated with Femoston alone) and the treatment group (treated with ZGP combined with Femoston) were assessed before and after treatment. Sex hormone levels, serum inflammatory cytokine levels, and ultrasound parameters were measured before and after treatment. POF rat models were established using cyclophosphamide and the POF rats were treated with Femoston, or ZGP combined with Femoston. GDF-9 and Smad2 expression levels were determined by RT-qPCR. The follicle-stimulating hormone (FSH), luteinizing hormone (LH), interleukin (IL)-6, and IL-21 levels, and the pulsatility index (PI) and resistance index (RI) values were decreased, while the estradiol (E2) and anti-Mullerian hormone (AMH) levels, antral follicle count (AFC), ovarian volume (OV), mean ovarian diameter (MOD), and peak systolic velocity (PSV) values were increased in the treatment group compared to the control group. After treatment with ZGP combined with Femoston, GDF-9 and Smad2 expression in the ovarian tissues of POF rats increased. ZGP has a therapeutic effect on POF via modulation of the GDF-9/Smad2 pathway.

Sex Determination and Ovarian Development in Reptiles and Amphibians: From Genetic Pathways to Environmental Influences

BACKGROUND

Reptiles and amphibians provide untapped potential for discovering how a diversity of genetic pathways and environmental conditions are incorporated into developmental processes that can lead to similar functional outcomes. These groups display a multitude of reproductive strategies, and whereas many attributes are conserved within groups and even across vertebrates, several aspects of sexual development show considerable variation.

SUMMARY

In this review, we focus our attention on the development of the reptilian and amphibian ovary. First, we review and describe the events leading to ovarian development, including sex determination and ovarian maturation, through a comparative lens. We then describe how these events are influenced by environmental factors, focusing on temperature and exposure to anthropogenic chemicals. Lastly, we identify critical knowledge gaps and future research directions that will be crucial to moving forward in our understanding of ovarian development and the influences of the environment in reptiles and amphibians.

KEY MESSAGES

Reptiles and amphibians provide excellent models for understanding the diversity of sex determination strategies and reproductive development. However, a greater understanding of the basic biology of these systems is necessary for deciphering the adaptive and potentially disruptive implications of embryo-by-environment interactions in a rapidly changing world.

Changes in IL-16 Expression in the Ovary during Aging and Its Potential Consequences to Ovarian Pathology

Aging in females is not only associated with the changes in hormonal status but is also responsible for dysregulation of immune functions in various organs including ovaries. The goal of this study was to determine whether the expression of interleukin 16 (IL-16), a proinflammatory and chemoattractant cytokine, changes during ovarian aging, to determine factors involved in such changes in IL-16 expression, and to examine if changes in IL-16 expression during aging predisposes the ovary to pathologies. Ovarian tissues from premenopausal women (30-50 years old), women at early menopause (55-59 years old), and late menopause (60-85 years old) were used. In addition, tumor tissues from patients with ovarian high-grade serous carcinoma at early stage (n = 5) were also used as reference tissue for comparing the expression of several selected markers in aging ovaries. The expression of IL-16, frequency of macrophages (a source of IL-16) and expression of microRNA (miR) 125a-5p (a regulator of IL-16 gene) were performed by immunohistochemistry, immunoblotting, and gene expression assays. In addition, we examined changes in nuclear expression of IL-16 expression with regards to exposure to follicle-stimulating hormone (FSH) by in vitro cell culture assays with human ovarian cancer cells. The frequencies of IL-16 expressing cells were significantly higher in ovarian stroma in women at early and late menopause as compared with premenopausal women (P < 0.0001). Similar patterns were also observed for macrophages. Expression of miR-125a-5p decreased significantly (P < 0.001) with the increase in IL-16 expression during aging. Furthermore, expression of nuclear IL-16 increased remarkably upon exposure to FSH. Consequently, ovarian aging is associated with increased expression of IL-16 including its nuclear fraction. Therefore, persistent high levels of FSH in postmenopausal women may be a factor for enhanced expression of IL-16. Effects of increased nuclear fraction of IL-16 need to be examined.

Research Progress on the Treatment of Premature Ovarian Failure Using Mesenchymal Stem Cells: A Literature Review

Premature ovarian failure (POF) has become one of the main causes of infertility in women of childbearing age and the incidence of POF is increasing year by year, seriously affecting the physical and mental health of patients and increasing the economic burden on families and society as a whole. The etiology and pathogenesis of POF are complex and not very clear at present. Currently, hormone replacement therapy is mainly used to improve the symptoms of low estrogen, but cannot fundamentally solve the fertility problem. In recent years, stem cell (SC) transplantation has become one of the research hotspots in the treatment of POF. The results from animal experiments bring hope for the recovery of ovarian function and fertility in patients with POF. In this article, we searched the published literature between 2000 and 2020 from the PubMed database (https://pubmed.ncbi.nlm.nih.gov), and summarized the preclinical research data and possible therapeutic mechanism of mesenchymal stem cells (MSCs) in the treatment of POF. Our aim is to provide useful information for understanding POF and reference for follow-up research and treatment of POF.

Antioxidative effect of dietary flavonoid isoquercitrin on human ovarian granulosa cells HGL5 in vitro

This study aimed to examine the effect of dietary flavonoid isoquercitrin on ovarian granulosa cells using the immortalized human cell line HGL5. Cell viability, survival, apoptosis, release of steroid hormones 17beta-estradiol and progesterone, and human transforming growth factor-beta2 (TGF-beta2) and TGF-beta2 receptor as well as intracellular reactive oxygen species (ROS) generation were investigated after isoquercitrin treatment at the concentration range of 5-100 microg.ml-1. It did not cause any significant change (p>0.05) in cell viability as studied by AlamarBlue assay in comparison to control. No significant change was observed (p>0.05) in the proportion of live, dead and apoptotic cells as revealed by apoptotic assay using flow cytometry. Similarly, the release of 17beta-estradiol, progesterone, TGF-beta2 and its receptor were not affected significantly (p>0.05) by isoquercitrin as detected by ELISA, in comparison to control. Except for the highest concentration of 100 microg.ml-1, which led to oxidative stress, isoquercitrin exhibited antioxidative activity at lower concentration used in the study (5, 10, 25, and 50 microg.ml-1) by hampering the production of intracellular ROS, in comparison to control, as detected by chemiluminescence assay (p<0.05). Findings of the present study indicate an existence of the antioxidative pathway that involves inhibition of intracellular ROS generation by isoquercitrin in human ovarian granulosa cells.

Is there any role of interleukin-6 and high sensitive C-reactive protein in predicting IVF/ICSI success? A prospective cohort study

OBJECTIVES

Studies have established a relationship between proinflammatory factors and implantation failure in IVF/ICSI cycles. Likewise, low-grade chronic inflammation is generally blamed for predisposing infertility. In the present study, we aimed to find a relationship between serum IL-6 and hs-CRP levels and IVF/ICSI cycle outcomes.

METHODS

A total of 129 patients who consented to participate and attended the IVF unit of our department for the treatment of infertility have been enrolled in this prospective cohort study. Serum levels of high sensitive C-reactive protein and interleukin 6 have been detected at the beginning of the IVF/ICSI ovulation induction cycle. Cycle outcomes have been compared between patients with and without clinical pregnancy achievement following ART treatments. IVF/ICSI cycle outcomes of these two groups were also comparable except the number of >14 mm follicles, retrieved oocytes, metaphase II oocytes, and fertilized oocytes (2 pronuclei) which were in favor of the clinical pregnancy group.

RESULTS

Mean serum hs-CRP levels were 3.08 mg/L (0.12-35.04) and 2.28 mg/L (0.09-22.52) patients with and without clinical pregnancy respectively. Mean serum IL-6 levels were 2 pg/mL (1-10.2) and 2 pg/mL (1-76.9) patients with and without clinical pregnancy respectively. Both tests were found to be statistically insignificant in predicting the success of the ART cycle in terms of implantation, clinical pregnancy, miscarriage, and live birth.

CONCLUSIONS

In the present study, we have not found any significant effect of hs-CRP and IL-6 levels in the IVF cycle. However, in the light of this and previous studies, large-scale research may prove the exact influence of these markers on IVF success.

Single-cell transcriptome dissection of the toxic impact of Di (2-ethylhexyl) phthalate on primordial follicle assembly

Rationale: Accumulated evidence indicates that environmental plasticizers are a threat to human and animal fertility. Di (2-ethylhexyl) phthalate (DEHP), a plasticizer to which humans are exposed daily, can trigger reproductive toxicity by acting as an endocrine-disrupting chemical. In mammals, the female primordial follicle pool forms the lifetime available ovarian reserve, which does not undergo regeneration once it is established during the fetal and neonatal period. It is therefore critical to examine the toxicity of DEHP regarding the establishment of the ovarian reserve as it has not been well investigated. Methods: The ovarian cells of postnatal pups, following maternal DEHP exposure, were prepared for single cell-RNA sequencing, and the effects of DEHP on primordial follicle formation were revealed using gene differential expression analysis and single-cell developmental trajectory. In addition, further biochemical experiments, including immunohistochemical staining, apoptosis detection, and Western blotting, were performed to verify the dataset results. Results: Using single-cell RNA sequencing, we revealed the gene expression dynamics of female germ cells and granulosa cells following exposure to DEHP in mice. Regarding germ cells: DEHP impeded the progression of follicle assembly and interfered with their developmental status, while key genes such as Lhx8, Figla, and others, strongly evidenced the reduction. As for granulosa cells: DEHP likely inhibited their proliferative activity, and activated the regulation of cell death. Furthermore, the interaction between ovarian cells mediated by transforming growth factor-beta signaling, was disrupted by DEHP exposure, since the expression of GDF9, BMPR1A, and SMAD3 was affected. In addition, DNA damage and apoptosis were elevated in germ cells and/or somatic cells. Conclusion: These findings offer substantial novel insights into the reproductive toxicity of DEHP exposure during murine germ cell cyst breakdown and primordial follicle formation. These results may enhance the understanding of DEHP exposure on reproductive health.

Protein hormone fragmentation in intercellular signaling: hormones as nested information systems

This study explores the hypothesis that protein hormones are nested information systems in which initial products of gene transcription, and their subsequent protein fragments, before and after secretion and initial target cell action, play additional physiological regulatory roles. The study produced four tools and key results: (1) a problem approach that proceeds, with examples and suggestions for in vivo organismal functional tests for peptide-protein interactions, from proteolytic breakdown prediction to models of hormone fragment modulation of protein-protein binding motifs in unrelated proteins; (2) a catalog of 461 known soluble human protein hormones and their predicted fragmentation patterns; (3) an analysis of the predicted proteolytic patterns of the canonical protein hormone transcripts demonstrating near-universal persistence of 9 ± 7 peptides of 8 ± 8 amino acids even after cleavage with 24 proteases from four protease classes; and (4) a coincidence analysis of the predicted proteolysis locations and the 1939 exon junctions within the transcripts that shows an excess (P < 0.001) of predicted proteolysis within 10 residues, especially at the exonal junction (P < 0.01). It appears all protein hormone transcripts generate multiple fragments the size of peptide hormones or protein-protein binding domains that may alter intracellular or extracellular functions by acting as modulators of metabolic enzymes, transduction factors, protein binding proteins, or hormone receptors. High proteolytic frequency at exonal junctions suggests proteolysis has evolved, as a complement to gene exon fusion, to extract structures or functions within single exons or protein segments to simplify the genome by discarding archaic one-exon genes.

Human placenta-derived mesenchymal stem cells stimulate ovarian function via miR-145 and bone morphogenetic protein signaling in aged rats

Background

Aging has detrimental effects on the ovary, such as a progressive reduction in fertility and decreased hormone production, that greatly reduce the quality of life of women. Thus, the current study was undertaken to investigate whether human placenta-derived mesenchymal stem cell (hPD-MSC) treatment can restore the decreases in folliculogenesis and ovarian function that occur with aging.

Methods

Acclimatized 52-week-old female SD rats were randomly divided into four groups: single hPD-MSC (5 × 10⁵) therapy, multiple (three times, 10-day intervals) hPD-MSC therapy, control (PBS), and non-treated groups. hPD-MSC therapy was conducted by tail vein injection into aged rats. The rats were sacrificed 1, 2, 3, and 5 weeks after the last injection. hPD-MSC tracking and follicle numbers were histologically confirmed. The serum levels of sex hormones and circulating miRNAs were detected by ELISA and qRT-PCR, respectively. TGF-β superfamily proteins and SMAD proteins in the ovary were detected by Western blot analysis.

Results

We observed that multiple transplantations of hPD-MSCs more effectively promoted primordial follicle activation and ovarian hormone (E₂ and AMH) production than a single injection. After hPD-MSC therapy, the levels of miR-21-5p, miR-132-3p, and miR-212-3p, miRNAs associated with the ovarian reserve, were increased in the serum. Moreover, miRNAs (miR-16-5p, miR-34a-5p, and miR-191-5p) with known adverse effects on folliculogenesis were markedly suppressed. Importantly, the level of miR-145-5p was reduced after single- or multiple-injection hPD-MSC therapy, and we confirmed that miR-145-5p targets Bmpr2 but not Tgfbr2. Interestingly, downregulation of miR-145-5p led to an increase in BMPR2, and activation of SMAD signaling concurrently increased primordial follicle development and the number of primary and antral follicles.

Conclusions

Our study verified that multiple intravenous injections of hPD-MSCs led to improved ovarian function via miR-145-5p and BMP-SMAD signaling and proposed the future therapeutic potential of hPD-MSCs to promote ovarian function in women at advanced age to improve their quality of life during climacterium.

GDF9 polymorphisms: influence on ovarian response in women undergoing controlled ovarian hyperstimulation

OBJECTIVE

The study looked into the possible influence of GDF9 polymorphisms on ovarian response in women with a normal ovarian reserve undergoing controlled ovarian hyperstimulation for in vitro fertilization (IVF).

METHODS

This cross-sectional study included 67 women with normal ovarian reserve aged 30-39 years submitted to controlled ovarian hyperstimulation for IVF. We sequenced four polymorphisms in the GDF9 gene (C398G, C447T, G546A, and G646A) and analyzed their influence on follicular and oocyte outcomes.

RESULTS

The mutant allele C398G decreased the total number of follicles >17mm (6.49 vs. 4.33, p=0.001), total number of follicles (10.11 vs. 7.33, p=0.032), number of MII oocytes retrieved, and serum progesterone levels on trigger day. The C447T polymorphism was associated with a greater number of follicles between 12 and 14 mm on the day of r-hCG, while the G546A polymorphism was associated with lower serum progesterone levels on trigger day.

CONCLUSIONS

GDF9 gene polymorphisms C398G and C447T adversely affected ovarian response in women undergoing controlled ovarian hyperstimulation. These findings show that in addition to playing a role in the early stages of folliculogenesis, GDF9 polymorphisms have an important impact on the final stage of oocyte development.

BMP-6 and SMAD4 gene expression is altered in cumulus cells from women with endometriosis-associated infertility

INTRODUCTION

Oocyte competence and quality depend on communication between the oocyte and the cumulus and theca cells. In the preantral phase, the members of the transforming growth factor β (TGF-β) superfamily are responsible for this communication and play an important role in folliculogenesis. Members of the TGF-β superfamily are related to endometriosis (overexpression in the ectopic endometrium); however, few studies have explored these proteins as influencing fertility in endometriosis. Considering endometriosis-related infertility and to better understand the role of the TGF-β superfamily members in the antral phase in women with endometriosis, this research investigated the gene expression of the genes for ligands AMH, BMP-6, GDF-9, INHA, INHBB, and TGFβ3; receptors AMHR2, BMPR2, and TGFβR3; and intracellular signalling: SMAD3 and SMAD4.

MATERIAL AND METHODS

The gene expression of AMH, BMP-6, GDF-9, INHA, INHBB, TGFβ3, AMHR2, BMPR2, TGFβR3, SMAD3, and SMAD4 in cumulus cells was investigated through quantitative real-time PCR in a case-control study including infertile women with and without peritoneal endometriosis undergoing in vitro fertilization.

RESULTS

Age and outcomes of assisted reproduction were similar between the groups (P > .05). However, women with endometriosis showed reduced expression of BMP-6 and SMAD4 (P < .05) in cumulus cells compared with the control group, other genes did not present altered gene expression in women with endometriosis (P > .05).

CONCLUSIONS

The reduced expression of BMP-6 and SMAD4 in women with peritoneal endometriosis compared with the control group indicates that granulosa (cumulus) cell function could be altered in these women.

Prediction of ovarian aging using ovarian expression of BMP15, GDF9, and C-KIT

IMPACT STATEMENT

Ovarian aging is becoming a more important issue in terms of fertility preservation and infertility treatment. Serum anti-Mullerian hormone (AMH) level and antral follicle count (AFC) are being practically used as markers of ovarian aging as well as ovarian reserve in human. However, these factors have some drawbacks in assessing ovarian aging and reserve. Therefore, the identification of ovarian expressions of BMP15, GDF9, and C-KIT according to female could be applied as a potent predictor of ovarian aging. This work provides new information on the development of diagnosis and treatment strategy of age-related fertility decline and premature ovarian insufficiency.

Dynamic Expression of Interleukin-33 and ST2 in the Mouse Reproductive Tract Is Influenced by Superovulation

Interleukin-33 (IL-33) is an IL-1 family cytokine with pleiotropic effects on diverse cell types. Dysregulated IL-33 signaling has been implicated in pregnancy-related disorders, including preeclampsia and recurrent pregnancy loss, and in ovarian function in women undergoing controlled ovarian stimulation for in vitro fertilization. To date, expression of IL-33 and its receptor subunit, ST2, in the female reproductive tract remains poorly characterized. We identify IL-33-expressing oocytes surrounded by ST2-expressing granulosa cells at all stages of follicular development, in addition to IL-33⁺ and ST2⁺ non-endothelial cells in the ovarian stroma and theca layer in ovaries from adult mice. These expression patterns are similar in estrus- and diestrus-stage adults and in pubescent mice, suggesting a role for IL-33 signaling in ovarian function throughout development and in the estrous cycle. In the uterus, we find expression of IL-33 and ST2 in glandular and luminal epithelia during estrus and at the initiation of pregnancy. Uterine IL-33 expression was modulated by the estrous cycle and was reduced in pubescent females. Last, superovulation increases transcripts for IL-33 and the soluble form of ST2 (sST2) in ovaries, and for IL-33 in uteri. Collectively, our findings lay the foundation for studies identifying cell type-specific requirements for IL-33/ST2 signaling in the establishment and maintenance of mouse pregnancy.

Effects of Inhibin A on Apoptosis and Proliferation of Bovine Granulosa Cells

Inhibin A is well known for its inhibitory properties against follicle-stimulating hormone (FSH), released through a pituitary-gonadal negative feedback loop to regulate follicular development. Ovarian folliculogenesis, hormonal biosynthesis, and gametogenesis are dependent on inhibins, playing vital roles in promoting or inhibiting cell proliferation. The present study explored the physiological and molecular response of bovine granulosa cells (GCs) to different concentrations of inhibin A in vitro. We treated the primary GCs isolated from ovarian follicles (3-6 mm) with different levels of inhibin A (20, 50, and 100 ng/mL) along with the control (0 ng/mL) for 24 h. To evaluate the impact of inhibin A on GCs, several in vitro cellular parameters, including cell apoptosis, viability, cell cycle, and mitochondrial membrane potential (MMP) were detected. Besides, the transcriptional regulation of pro-apoptotic (BAX, Caspase-3) and cell proliferation (PCNA, CyclinB1) genes were also quantified. The results indicated a significant (p < 0.05) increase in the cell viability in a dose-dependent manner of inhibin A. Likewise, MMP was significantly (p < 0.05) enhanced when GCs were treated with high doses (50, 100 ng/mL) of inhibin A. Furthermore, inhibin A dose (100 ng/mL) markedly improved the progression of the G1 phase of the cell cycle and increased the cell number in the S phase, which was supported by the up-regulation of the proliferating cell nuclear antigen PCNA (20, 50, and 100ng/mL) and CyclinB (100 ng/mL) genes. In addition, higher doses of inhibin A (50 and 100 ng/mL) significantly (p < 0.05) decreased the apoptotic rate in GCs, which was manifested by down regulating BAX and Caspase-3 genes. Conclusively, our study presented a worthy strategy for the first time to characterize the cellular adaptation of bovine GCs under different concentrations of inhibin A. Our results conclude that inhibin A is a broad regulatory marker in GCs by regulating apoptosis and cellular progression.

Activation of Notch Signaling by Oocytes and Jag1 in Mouse Ovarian Granulosa Cells

The Notch pathway plays diverse and complex roles in cell signaling during development. In the mammalian ovary, Notch is important for the initial formation and growth of follicles, and for regulating the proliferation and differentiation of follicular granulosa cells during the periovulatory period. This study seeks to determine the contribution of female germ cells toward the initial activation and subsequent maintenance of Notch signaling within somatic granulosa cells of the ovary. To address this issue, transgenic Notch reporter (TNR) mice were crossed with Sohlh1-mCherry (S1CF) transgenic mice to visualize Notch-active cells (EGFP) and germ cells (mCherry) simultaneously in the neonatal ovary. To test the involvement of oocytes in activation of Notch signaling in ovarian somatic cells, we ablated germ cells using busulfan, a chemotherapeutic alkylating agent, or investigated KitWv/Wv (viable dominant white-spotting) mice that lack most germ cells. The data reveal that Notch pathway activation in granulosa cells is significantly suppressed when germ cells are reduced. We further demonstrate that disruption of the gene for the Notch ligand Jag1 in oocytes similarly impacts Notch activation and that recombinant JAG1 enhances Notch target gene expression in granulosa cells. These data are consistent with the hypothesis that germ cells provide a ligand, such as Jag1, that is necessary for activation of Notch signaling in the developing ovary.

Prostaglandin F2α-induced Prostate Transmembrane Protein, Androgen Induced 1 mediates ovarian cancer progression increasing epithelial plasticity

The role of prostaglandin (PG) F_2α has been scarcely studied in cancer. We have identified a new function for PGF_2α in ovarian cancer, stimulating the production of Prostate Transmembrane Protein, Androgen Induced 1 (PMEPA1). We show that this induction increases cell plasticity and proliferation, enhancing tumor growth through PMEPA1. Thus, PMEPA1 overexpression in ovarian carcinoma cells, significantly increased cell proliferation rates, whereas PMEPA1 silencing decreased proliferation. In addition, PMEPA1 overexpression buffered TGFβ signaling, via reduction of SMAD-dependent signaling. PMEPA1 overexpressing cells acquired an epithelial morphology, associated with higher E-cadherin expression levels while β-catenin nuclear translocation was inhibited. Notwithstanding, high PMEPA1 levels also correlated with epithelial to mesenchymal transition markers, such as vimentin and ZEB1, allowing the cells to take advantage of both epithelial and mesenchymal characteristics, gaining in cell plasticity and adaptability. Interestingly, in mouse xenografts, PMEPA1 overexpressing ovarian cells had a clear survival and proliferative advantage, resulting in higher metastatic capacity, while PMEPA1 silencing had the opposite effect. Furthermore, high PMEPA1 expression in a cohort of advanced ovarian cancer patients was observed, correlating with E-cadherin expression. Most importantly, high PMEPA1 mRNA levels were associated with lower patient survival.

Similar miRNomic signatures characterize the follicular fluids collected after follicular and luteal phase stimulations in the same ovarian cycle

PURPOSE

To detect putative differences in the miRNomic profile of follicular fluids collected after follicular-phase-stimulation (FPS-FFs) and paired luteal-phase-stimulation (LPS-FFs) in the same ovarian cycles (DuoStim).

METHODS

Exploratory study at a private IVF center and University involving FPS-FFs and paired-LPS-FFs collected from 15 reduced ovarian reserve and advanced maternal age women undergoing DuoStim (n = 30 paired samples). The samples were combined in 6 paired pools (5 samples each) and balanced according to maternal age and number of cumulus-oocyte-complexes. Micro-RNAs were isolated and sequenced. Four miRNAs were then selected for further validation on 6 single pairs of FPS-FFs and LPS-FFs by qPCR.

RESULTS

Forty-three miRNAs were detected in both FPS-FFs and paired-LPS-FFs after sequencing and no statistically significant differences were reported. Thirty-three KEGG pathways were identified as regulated from the detected miRNAs. Four miRNAs (miR-146b, miR-191, miR-320a, and miR-483) were selected for qPCR validation since consistently expressed in our samples and possibly involved in the regulation/establishment of a healthy follicular environment. Again, no significant differences were reported between FPS-FFs and paired-LPS-FFs, also when the analysis was corrected for maternal age and number of cumulus-oocyte-complexes in generalized linear models.

CONCLUSIONS

These data complement the embryological, chromosomal, and clinical evidence of equivalence between FPS and LPS published to date.

Association of BMP15 and GDF9 variants to premature ovarian insufficiency

PURPOSE

To identify genetic variation associated to premature ovarian insufficiency (POI).

METHODS

A total of 74 women with POI (group POI), 45 women with increased FSH levels (group high FSH), and 88 controls (non-POI) were studied. Genotyping of BMP15:c.-9C>G (rs3810682), BMP15:c.328+905A>G (rs3897937), and BMP15:c.852C>T (rs17003221); and GDF9:c.134-694G>A (rs4705974), GDF9:c.-31-951G>A (rs11748063), GDF9:c.-152G>C (rs30177), and GDF9:g.1073C>T (rs803224) was performed by the TaqMan methodology. Chi-square and Fisher's exact tests were performed to evaluate the distribution of genotypes, alleles, odds ratio, and the Hardy-Weinberg equilibrium of each variation. Haplotype analysis was performed for each gene considering the case and control groups. Bonferroni's correction was applied to chi-square and Fisher's exact test data, and p values < 0.007 for genotypes and alleles and < 0.006 for haplotypes were considered significant.

RESULTS

It was observed a statistically significant difference in genotype distribution of BMP15:c.852C>T between group POI and controls (p < 0.001). TT and TC genotypes were more frequently observed in group POI. Genotype distribution in case group POI, however, was not in the Hardy-Weinberg equilibrium, due to the increased number of heterozygotes in the sample. Concerning GDF9, no association was found among the studied genetic variants and POI or high FSH groups.

CONCLUSION

It is concluded from the present study that the genotypes CT and TT from BMP15:c.852C>T variation may be risk factors for the development of POI.

Non-canonical cyclic AMP SMAD1/5/8 signalling in human granulosa cells

Development of mammalian ovarian follicles is promoted by the combined action of endocrine cues and paracrine factors. Follicle stimulating hormone (FSH), through the action of cAMP drives follicular growth and development. The oocyte secretes powerful growth factors such as bone morphogenetic protein 15 (BMP15) to regulate granulosa cell proliferation, metabolism, steroidogenesis and differentiation through the activation of SMAD1/5/8. This study investigated the role of the cAMP signalling pathway on SMAD1/5/8 action in human granulosa cells. Cyclic AMP enhanced BMP15-induction of a SMAD1/5/8-specific BRE reporter. Moreover, in the absence of BMP ligand, cAMP also activated SMAD1/5/8-induced BRE activity. Cyclic AMP increased canonical downstream targets of BMP signalling such as inhibitor of differentiation (ID) mRNA expression. The observed effects were not mediated by secretion of BMPs as cAMP did not promote BMP ligand mRNA expression and a BMP extracellular antagonist, the BMP type II receptor ectodomain, did not affect cAMP-induced ID mRNA expression. Finally, the ERK1/2 pathway was shown to be required for the maintenance of cAMP-induced SMAD1/5/8 activity. Together our results suggest a novel and non-canonical pathway for cAMP signalling in human granulosa cells. Cyclic AMP appears to promote SMAD1/5/8 pathway activity intracellularly and has the ability to activate canonical SMAD1/5/8 downstream targets. Our results add another layer of complexity to the interactions between endocrine signalling and oocyte-secreted BMP ligands during folliculogenesis. Given the importance of both cAMP and SMAD1/5/8 pathways in follicular development, these interactions are likely required for the fine-tuning of oocyte paracrine signalling by endocrine stimuli.

Identification of a bone morphogenetic protein type 2 receptor neutralizing antibody

OBJECTIVE

The bone morphogenetic protein (BMP) signaling pathway comprises the largest subdivision of the transforming growth factor (TGFβ) superfamily. BMP signaling plays essential roles in both embryonic development and postnatal tissue homeostasis. Dysregulated BMP signaling underlies human pathologies ranging from pulmonary arterial hypertension to heterotopic ossification. Thus, understanding the basic mechanisms and regulation of BMP signaling may yield translational opportunities. Unfortunately, limited tools are available to evaluate this pathway, and genetic approaches are frequently confounded by developmental requirements or ability of pathway components to compensate for one another. Specific inhibitors for type 2 receptors are poorly represented. Thus, we sought to identify and validate an antibody that neutralizes the ligand-binding function of BMP receptor type 2 (BMPR2) extracellular domain (ECD).

RESULTS

Using a modified, cell-free immunoprecipitation assay, we examined the neutralizing ability of the mouse monoclonal antibody 3F6 and found a dose-dependent inhibition of BMPR2-ECD ligand-binding. Consistent with this, 3F6 blocks endogenous BMPR2 function in the BMP-responsive cell line HEK293T. The specificity of 3F6 action was confirmed by demonstrating that this antibody has no effect on BMP-responsiveness in HEK293T cells in which BMPR2 expression is knocked-down. Our results provide important proof-of-concept data for future studies interrogating BMPR2 function.

An integrated investigation of oocyte developmental competence: expression of key genes in human cumulus cells, morphokinetics of early divisions, blastulation, and euploidy

PURPOSE

To investigate the association of cumulus cell (CC)-related expression of a selected cluster of key genes (PTGS2, CAMK1D, HAS2, STC1, and EFNB2) with embryo development to blastocyst.

METHODS

Exploratory study at a private clinic. Eighteen advanced maternal age patients were enrolled (37.3 ± 4.0 years). Seventy-five cumuli were collected, whose oocytes resulted in either developmental arrest (N = 33) or blastocyst formation (N = 42). The noninvasive CC gene expression was combined with time-lapse morphokinetic parameters and, for blastocysts, with qPCR-based aneuploidy testing on trophectoderm biopsies.

RESULTS

The detection rate was 100% for all transcripts, but STC1 (96%) and CAMK1D (89%). Among amplified assays, CC mean expression levels of CAMK1D, PTGS2, and HAS2 were higher from oocytes that developed to blastocyst. No difference in CC key gene expression was reported between euploid (N = 21) and aneuploid (N = 21) blastocysts. Some timings of early embryo development were faster in embryos developing to blastocyst (time of pronuclei appearance and fading, division to two- and four-cells, first and second cell cycles). However, the generalized linear models outlined increasing CAMK1D expression levels as the strongest parameter associated with oocytes' developmental potential from both a general (AUC = 0.78 among amplified samples) and an intrapatient perspectives (AUC = 0.9 among patients obtaining ≥ 2 zygotes from the cohort with different developmental outcomes).

CONCLUSIONS

CAMK1D level of expression in CCs associated with blastocyst development. If confirmed from larger studies in wider populations of patients, the investigation of CC key gene expression might suit IVF clinics not adopting blastocyst culture. Future investigations should clarify the role of CAMK1D in ovarian physiology and could provide novel insights on how oocytes gain competence during folliculogenesis.

Evaluation of Serum miRNA-24, miRNA-29a and miRNA-502-3p Expression in PCOS Subjects: Correlation with Biochemical Parameters Related to PCOS and Insulin Resistance

MicroRNAs (miRNAs) are small, endogenous, non-coding, single stranded RNAs which play a role in the regulation of gene expression and function. Therefore, the analysis of differentially expressed miRNAs are of great importance in disease diagnosis. This study is focussed on the differential expression of miRNAs in serum of PCOS subjects compared to control and their correlation with metabolic and endocrine parameters. Anthropometry, hormone concentrations and biochemical characteristics were measured in healthy (n = 20) and PCOS (n = 20) subjects. MiR-24, miR-29a and miR-502-3p were determined in serum by quantitative RT-PCR. The levels of miR-24 was significantly decreased in PCOS subjects (P = 0.00) compared to control. No significant difference was observed in the levels of miR-29a and miR-502-3p in PCOS and control subjects. MiR-24 showed significant inverse correlation with BMI, glucose, insulin, FIRI, HOMA, LH, testosterone, TG, and LH:FSH ratio whereas HDL levels showed significant positive association with miR-24 and miR-29a. LH showed significant negative association with miR-29a. No correlation was observed between the expression of miR-502-3p with any of the studied parameters. The receiver operating characteristic curve for miR-24 alone showed a significant discriminative capacity. The study suggests that serum miR-24 analysis in PCOS patients could be of diagnostic value that can be used as a biomarker for PCOS.

Is there a correlation between follicle size and gene expression in cumulus cells and is gene expression an indicator of embryo development?

BACKGROUND

In an article published in 2017, we discussed the results of the first part of our study into the morphokinetic development of embryos in relation to follicle diameter and homogeneity of follicular development. Our findings showed that embryos coming from small follicles in heterogeneous cycles had significantly higher rates of arrest or failure to reach blastocyst than embryos coming from large follicles in homogenous cycles. The aim of this further study was to investigate the relationship between follicular size and gene expression of cumulus cells (CCs) and evaluate whether gene expression could be an indicator of embryo development.

METHODS

This study was based on 2495 COCs from 184 patients. CC expressions of five genes (TNFAIP6, PTGS2, HAS2, PTX3 and GDF9) were studied by generalized linear mixed models (GLMMs) regarding follicular size. CC expressions were then separately analysed regarding patient-specific variables (age, BMI, AMH and follicular size) in relation to embryos reaching blastocyst (eRB) or top or good quality blastocysts (TQ + GQ) using GLMMs with logit link.

RESULTS

Follicular size significantly correlated with the potential of an oocyte to develop into a blastocyst: oocytes developing from large follicles were more than twice as likely to develop into an eRB than oocytes from small follicles (p < 0.001). Gene expression of HAS2 and GDF9 correlated with blastocyst quality when separately evaluated with follicular size and the patient specific variables of age, BMI and AMH. However, no such correlation was found in other gene expressions studied.

CONCLUSIONS

Our findings suggest that differences in the expression of genes studied could be related to follicular size rather than to embryo quality. Although gene expression of HAS2 and GDF9 correlated with blastocyst quality, the only variable correlating with eRB and TQ and GQ blastocysts for each of these five models was follicular size.

TRIAL REGISTRATION

This prospective cohort study was registered at clinicaltrials.gov (NCT02230449).

Vasorin: a newly identified regulator of ovarian folliculogenesis

Members of the TGF-β superfamily take part in the control of folliculogenesis. Vasorin (Vasn) is a newly identified negative regulator of TGF-β signaling whose possible involvement in ovarian physiology has never been studied. Here, we demonstrate that Vasn is expressed in the ovary by somatic cells of follicles, and that its expression is up-regulated by LH. We established a conditional knockout (cKO) mouse model in which Vasn is deleted specifically in granulosa cells of growing follicles from the secondary stage onwards. Using this model, we show that, upon hormonal stimulation, follicle ovulation size is almost 2-fold higher. This enhanced ovulatory response is associated with overactivation of the TGF-β signaling pathway and a lower number of atretic antral follicles. Of importance, we demonstrate that the number of primordial follicles is reduced in prepubertal cKO mouse ovaries, which suggests that the production of VASN by growing follicles protects the ovarian reserve. Finally, analysis of systemic KO mice revealed that the ovarian reserve is almost 2.5-fold higher, which implies that Vasn may also play a role in primordial follicle formation. Overall, our findings reveal that Vasn is a new regulator that exerts an effect on several key ovarian functions, including folliculogenesis, maintenance of the ovarian reserve, and ovulation.-Rimon-Dahari, N., Heinemann-Yerushalmi, L., Hadas, R., Kalich-Philosoph, L., Ketter, D., Nevo, N., Galiani, D., Dekel, N. Vasorin: a newly identified regulator of ovarian folliculogenesis.

TGFβ superfamily signaling and uterine decidualization

Decidualization is an intricate biological process where extensive morphological, functional, and genetic changes take place in endometrial stromal cells to support the development of an implanting blastocyst. Deficiencies in decidualization are associated with pregnancy complications and reproductive diseases. Decidualization is coordinately regulated by steroid hormones, growth factors, and molecular and epigenetic mechanisms. Transforming growth factor β (TGFβ) superfamily signaling regulates multifaceted reproductive processes. However, the role of TGFβ signaling in uterine decidualization is poorly understood. Recent studies using the Cre-LoxP strategy have shed new light on the critical role of TGFβ signaling machinery in uterine decidualization. Herein, we focus on reviewing exciting findings from studies using both mouse genetics and in vitro cultured human endometrial stromal cells. We also delve into emerging mechanisms that underlie decidualization, such as non-coding RNAs and epigenetic modifications. We envision that future studies aimed at defining the interrelationship among TGFβ signaling circuitries and their potential interactions with epigenetic modifications/non-coding RNAs during uterine decidualization will open new avenues to treat pregnancy complications associated with decidualization deficiencies.

Follistatin Rescues Blastocyst Development of Poor Quality Porcine Cumulus-Oocyte Complexes by Delaying Meiotic Resumption With Decreased cGMP

Mammalian oocytes resume maturation when removed from follicles and cultured in vitro. During folliculogenesis, oocytes are bathed in follicular fluid (FF), which provides an important and specialized microenvironment for oocyte competence. Follistatin (FST) is one component of FF that may play a role in oocyte maturation and embryo development. This study was conducted to examine possible effects of FST on porcine oocyte competence and embryo development. Exogenous FST in oocyte maturation medium for 22 or 44 hours did not improve nuclear maturation and had no effect on good quality cumulus-oocyte complexes (COCs). However, FST improved blastocyst rates in embryos derived from oocytes with less than 2 layers of cumulus. Follistatin treatment of the poor quality COC group increased transcript levels for genes indicative of oocyte quality. Transcript levels were also altered for cumulus expansion-related genes in response to FST when measured during the germinal vesicle breakdown stage. Interestingly, high-quality oocytes remained at germinal vesicle stage much longer than low-quality oocytes, FST treatment induced temporary blockage of spontaneous meiotic resumption when added during culture of both good and poor quality COCs, and levels of cyclic guanosine monophosphate (cGMP) were higher in FST-treated versus untreated groups for both good and poor quality oocytes. In conclusion, FST treatment of porcine oocytes during in vitro maturation can rescue competency of poor quality oocytes to develop to blastocyst stage following in vitro fertilization. Beneficial effects of addition of FST to culture medium may be mediated by inhibiting degradation of cGMP and temporarily delaying nuclear maturation.

Endometriosis-associated infertility: GDF-9, AMH, and AMHR2 genes polymorphisms

PURPOSE

The purpose of this paper is to determine whether there is a correlation between polymorphisms in the growth differentiation factor-9 (GDF-9) gene and anti-Müllerian hormone (AMH) gene and its receptor, AMHR2, and endometriosis-associated infertility.

METHODS

This is a case-control study to evaluate whether there is a correlation between polymorphisms in the GDF-9 gene (SNPs determined by direct sequencing), AMH gene, AMHR2 (both SNPs determined by genotyping using TaqMan Allelic Discrimination), and endometriosis-associated infertility. The study included 74 infertile women with endometriosis and 70 fertile women (tubal ligation) as a control group.

RESULTS

Patient age and the mean FSH levels were similar between the infertile with endometriosis and fertile without endometriosis groups. The frequency of genotypes between the groups for GDF-9 gene polymorphisms did not show statistical significance, nor did the AMHR2 gene polymorphism. However, the AMH gene polymorphism did show statistical significance, relating the polymorphic allele with infertility in endometriosis.

CONCLUSIONS

We demonstrate that an SNP in the AMH gene is associated with infertility in endometriosis, whereas several SNPs in the GDF-9 gene and the - 482A G SNP in the AMHR2 gene were found to be unrelated.

Is the oocyte quality affected by endometriosis? A review of the literature

Endometriosis is an estrogen-dependent chronic inflammatory condition that affects women in their reproductive period causing infertility and pelvic pain. The disease, especially at the ovarian site has been shown to have a detrimental impact on ovarian physiology. Indeed, sonographic and histologic data tend to support the idea that ovarian follicles of endometriosis patients are decreased in number and more atretic. Moreover, the local intrafollicular environment of patients affected is characterized by alterations of the granulosa cell compartment including reduced P450 aromatase expression and increased intracellular reactive oxygen species generation. However, no comprehensive evaluation of the literature addressing the effect of endometriosis on oocyte quality from both a clinical and a biological perspective has so far been conducted. Based on this systematic review of the literature, oocytes retrieved from women affected by endometriosis are more likely to fail in vitro maturation and to show altered morphology and lower cytoplasmic mitochondrial content compared to women with other causes of infertility. Results from meta-analyses addressing IVF outcomes in women affected would indicate that a reduction in the number of mature oocytes retrieved is associated with endometriosis while a reduction in fertilization rates is more likely to be associated with minimal/mild rather than with moderate/severe disease. However, evidence in this field is still far to be conclusive, especially with regards to the effects of different stages of the disease and to the impact of patients’ previous medical/surgical treatment(s).

The role of germ cell loss during primordial follicle assembly: a review of current advances

In most female mammals, early germline development begins with the appearance of primordial germ cells (PGCs), and develops to form mature oocytes following several vital processes. It remains well accepted that significant germ cell apoptosis and oocyte loss takes place around the time of birth. The transition of the ovarian environment from fetal to neonatal, coincides with the loss of germ cells and the timing of follicle formation. All told it is common to lose approximately two thirds of germ cells during this transition period. The current consensus is that germ cell loss can be attributed, at least in part, to programmed cell death (PCD). Recently, autophagy has been implicated as playing a part in germ cell loss during the time of parturition. In this review, we discuss the major opinions and mechanisms of mammalian ovarian PCD during the process of germ cell loss. We also pay close attention to the function of autophagy in germ cell loss, and speculate that autophagy may also serve as a critical and necessary process during the establishment of primordial follicle pool.

The role of Notch signaling in the mammalian ovary

The Notch pathway is a contact-dependent, or juxtacrine, signaling system that is conserved in metazoan organisms and is important in many developmental processes. Recent investigations have demonstrated that the Notch pathway is active in both the embryonic and postnatal ovary and plays important roles in events including follicle assembly and growth, meiotic maturation, ovarian vasculogenesis and steroid hormone production. In mice, disruption of the Notch pathway results in ovarian pathologies affecting meiotic spindle assembly, follicle histogenesis, granulosa cell proliferation and survival, corpora luteal function and ovarian neovascularization. These aberrations result in abnormal folliculogenesis and reduced fertility. The knowledge of the cellular interactions facilitated by the Notch pathway is an important area for continuing research, and future studies are expected to enhance our understanding of ovarian function and provide critical insights for improving reproductive health. This review focuses on the expression of Notch pathway components in the ovary, and on the multiple functions of Notch signaling in follicle assembly, maturation and development. We focus on the mouse, where genetic investigations are possible, and relate this information to the human ovary.

Stem cell factor promotes in vitro ovarian follicle development in the domestic cat by upregulating c-kit mRNA expression and stimulating the phosphatidylinositol 3-kinase/AKT pathway

In the present study we examined the effects of stem cell factor (SCF; 50 vs 100 ng mL–1) alone or in combination with epidermal growth factor (EGF; 100 ng mL–1) on: (1) the in vitro viability and growth of cat follicles within ovarian cortices; (2) phosphatidylinositol 3-kinase (PI3K)/AKT and mitogen-activated protein kinase (MAPK) phosphorylation; and (3) c-kit and FSH receptor (FSHr) mRNA expression. At 100 ng mL–1, SCF increased (P ≤ 0.05) the percentage and size of secondary follicles after 14 days of in vitro culture and sustained AKT phosphorylation after 3 days incubation. EGF suppressed this beneficial effect and reduced (P ≤ 0.05) the percentage of structurally normal follicles and FSHr expression when combined with 100 ng mL–1 SCF. Expression of c-kit mRNA was higher (P ≤ 0.05) in the presence of 100 ng mL–1 SCF compared with fresh follicles and cohorts cultured under other conditions. A c-kit inhibitor suppressed follicle growth and reduced AKT phosphorylation. Collectively, the results demonstrate that SCF promotes cat follicle development by upregulating c-kit mRNA expression and AKT phosphorylation. EGF suppresses the stimulating effect of SCF, leading to downregulation of FSHr expression.

Macrophage Inhibitory Cytokine-1 as a Novel Diagnostic and Prognostic Biomarker in Stage I and II Nonsmall Cell Lung Cancer

BACKGROUND

Increased level of serum macrophage inhibitory cytokine-1 (MIC-1), a member of transforming growth factor-μ superfamily, was found in patients with epithelial tumors. This study aimed to evaluate whether serum level of MIC-1 can be a candidate diagnostic and prognostic indicator for early-stage nonsmall cell lung cancer (NSCLC).

METHODS

A prospective study enrolled 152 patients with Stage I-II NSCLC, who were followed up after surgical resection. Forty-eight patients with benign pulmonary disease (BPD) and 105 healthy controls were also included in the study. Serum MIC-1 levels were measured using an enzyme-linked immunosorbent assay, and the association with clinical and prognostic features was analyzed.

RESULTS

In patients with NSCLC, serum protein levels of MIC-1 were significantly increased compared with healthy controls and BPD patients (all P< 0.001). A threshold of 1000 pg/ml of MIC-1 was found in patients with early-stage (Stage I and II) NSCLC, with sensitivity and specificity of 70.4% and 99.0%, respectively. The serum levels of MIC-1 were associated with age (P = 0.001), gender (P = 0.030), and T stage (P = 0.022). Serum MIC-1 threshold of 1465 pg/ml was found in patients with poor early outcome, with sensitivity and specificity of 72.2% and 66.1%, respectively. The overall 3-year survival rate of NSCLC patients with high serum levels of MIC-1 (≥1465 pg/ml) was lower than that of NSCLC patients with low serum MIC-1 levels (77.6% vs. 94.8%). Multivariate Cox regression survival analysis showed that a high serum level of MIC-1 was an independent risk factor for reduced overall survival (hazard ratio = 3.37, 95% confidential interval: 1.09-10.42, P= 0.035).

CONCLUSION

The present study suggested that serum MIC-1 may be a potential diagnostic and prognostic biomarker for patients with early-stage NSCLC.

Intrafollicular interleukin-8, interleukin-12, and adrenomedullin are the promising prognostic markers of oocyte and embryo quality in women with endometriosis

PURPOSE

The study aimed to investigate key intrafollicular prognostic factors among various cytokines and angiogenic molecules for prediction of mature oocytes and good-quality embryos in women with endometriosis undergoing in vitro fertilization (IVF).

METHODS

Paired follicular fluid and serum samples were collected from 200 women with advanced stage endometriosis and 140 normal ovulating women during oocyte retrieval. The concentrations of cytokines (pro-inflammatory: IL-1β, TNF-α, IL-2, IL-8, IL-12, IFN-γ; anti-inflammatory: IL-4, IL-6, IL-10) and angiogenic molecules (vascular endothelial growth factor (VEGF), adrenomedullin, angiogenin) were determined in follicular fluid and serum using ELISA. Expression of these molecules was subjected to multivariate analysis for the identification of major predictive markers of oocyte and embryo quality. Receiver operating characteristic (ROC) curve was applied to determine the best cutoff point for the discrimination between mature and immature oocytes in these women.

RESULTS

Significant increases in levels of cytokines and angiogenic molecules were observed in women with endometriosis compared to controls (P < 0.001). From the validated partial least squares-discriminant analysis (PLS-DA) model, IL-8, IL-12, and adrenomedullin were identified as the most important factors contributing to endometriosis and were negatively associated with oocyte maturity and embryo quality.

CONCLUSION

The levels of IL-8, IL-12, and adrenomedullin may be good indicators of embryo and oocyte quality in endometriosis patients undergoing IVF. Further studies are necessary to ascertain the potential of these markers for oocyte and embryo developmental competence which may help improve the chances of a successful IVF in endometriosis patients.

Activins and Inhibins: Roles in Development, Physiology, and Disease

Since their original discovery as regulators of follicle-stimulating hormone (FSH) secretion and erythropoiesis, the TGF-β family members activin and inhibin have been shown to participate in a variety of biological processes, from the earliest stages of embryonic development to highly specialized functions in terminally differentiated cells and tissues. Herein, we present the history, structures, signaling mechanisms, regulation, and biological processes in which activins and inhibins participate, including several recently discovered biological activities and functional antagonists. The potential therapeutic relevance of these advances is also discussed.

MicroRNA Species in Follicular Fluid Associating With Polycystic Ovary Syndrome and Related Intermediary Phenotypes

CONTEXT

Polycystic ovary syndrome (PCOS) has a largely unknown etiology and presents with a clinical heterogeneous patient group. Small noncoding microRNA (miRNA) might prove promising as biomarker candidates for PCOS patient stratification. Altered miRNA expression profiles have been observed in few studies.

OBJECTIVE

The aim was to assess the miRNA expression profile in follicular fluid from PCOS patients and healthy, regularly cycling, matched controls.

DESIGN AND SETTING

Experimental case-control study including 49 PCOS women (19 of which were hyperandrogenic and 30 normo-androgenic) and 21 healthy matched women all undergoing in vitro fertilization treatment.

INTERVENTIONS AND MAIN OUTCOME

Anthropometric and relevant clinical baseline measurements were obtained. Relative expression of miRNA levels were estimated using miRNA quantitative PCR arrays and validated by quantitative RT-PCR. Correlation between miRNAs and clinical relevant measurements was estimated.

RESULTS

PCOS women, both normo-androgenic and hyperandrogenic, had decreased levels of miR-24-3p, -29a, -151-3p, and -574-3p compared with controls. Furthermore, miR-518f-3p was differentially expressed within the PCOS group with high levels observed in the hyperandrogenic group compared with the normo-androgenic PCOS patients. Serum levels of total and free T were positively correlated with miR-518f-3p in PCOS subjects (P = .001). Distinction between PCOS and controls could be made using miR-151-3p alone with an area under the curve of 0.91 or a combination of four selected miRNAs (area under the curve, 0.93). Bioinformatic target analysis points to an involvement of these miRNAs in biological pathways involving regulation of cell proliferation, extracellular matrix, and processes in intermediary metabolism.

CONCLUSION

Our study provides evidence that the miRNA expression profile in follicular fluid is altered in PCOS and indicates that specific follicular fluid miRNAs are associated with phenotypical traits of PCOS. An altered miRNA profile holds potentials for new methods of PCOS patient stratification and may contribute to and in part explain the heterogeneous nature found within PCOS women.