Comparisons of follicular levels of sex steroids, gonadotropins and insulin like growth factor-1 (IGF-1) and epidermal growth factor (EGF) in poor responder and normoresponder patients undergoing ovarian stimulation with GnRH antagonist

Molecular crosstalk between insulin-like growth factors and follicle-stimulating hormone in the regulation of granulosa cell function

Background

The last phase of folliculogenesis is driven by follicle-stimulating hormone (FSH) and locally produced insulin-like growth factors (IGFs), both essential for forming preovulatory follicles.

Methods

This review discusses the molecular crosstalk of the FSH and IGF signaling pathways in regulating follicular granulosa cells (GCs) during the antral-to-preovulatory phase.

Main findings

IGFs were considered co-gonadotropins since they amplify FSH actions in GCs. However, this view is not compatible with data showing that FSH requires IGFs to stimulate GCs, that FSH renders GCs sensitive to IGFs, and that FSH signaling interacts with factors downstream of AKT to stimulate GCs. New evidence suggests that FSH and IGF signaling pathways intersect at several levels to regulate gene expression and GC function.

Conclusion

FSH and locally produced IGFs form a positive feedback loop essential for preovulatory follicle formation in all species. Understanding the mechanisms by which FSH and IGFs interact to control GC function will help design new interventions to optimize follicle maturation, perfect treatment of ovulatory defects, improve in vitro fertilization, and develop new contraceptive approaches.

Effect of growth hormone administration on ameliorating pregnancy outcome in women with advanced maternal age and exploration of its optimized utilization

Background

Age-related fertility decay is a great challenge for clinicians. Growth hormone (GH) supplementation has been studied as an adjuvant since late 1980s. However, it has not come to a consensus on the GH administration due to the ambiguous efficacy among studies with different enrolled population and dosage regime.

Methods

A self-controlled retrospective study was conducted on women with advanced maternal age who underwent at least a previous cycle without GH (GH-) and a subsequent cycle with GH co-treatment (GH+). The ovarian stimulation parameters and outcomes were compared between the two cycles and logistical analysis was applied to further explore the association between GH administration protocol as well as other clinical parameters and cumulative live birth in GH+cycle.

Results

A total of 150 women aged 35-43 were included. The number of oocytes retrieved, MII oocytes, 2PNs, transferrable embryos and good-quality embryos in GH+ significantly increased (p < 0.001). The proportion of cycles with no transferrable embryos was significantly reduced in GH+ cycle compared with previous GH- cycle (3 vs. 32; p < 0.001). GH co-treatment cycles showed significantly higher clinical pregnancy rates (43.75% vs. 6.06%; 38.35% vs. 12.04%, p < 0.001), live birth rates (29.17% vs. 0; 27.07% vs. 0, p < 0.001) in both fresh and frozen-thawed embryo transfer cycle. Cumulative live birth rate of the GH+ cycle reached 33.33%. Use of GH prior to Gn stimulation and lasting until the hCG day seemed to achieve a higher successful live birth rate (OR 2.312, 95%CI 1.074-5.163, p=0.032).

Conclusion

GH supplementation could ameliorate pregnancy outcome in women with advanced maternal age. Dosage regimen of long-term pretreatment prior to Gn stimulation (4 IU every other day) and 4 IU per day until hCG day may of greater efficacy compared with concurrent administration with Gn. Additionally, it's worthy of exploring whether an individualized dosage regimen based on the IGF or IGFBP level of patient would be more reasonable and effective. More well-designed prospective trials with large sample size and fundamental experiments on the mechanism are required to testify findings above.

An in silico model using prognostic genetic factors for ovarian response in controlled ovarian stimulation: A systematic review

PURPOSE

To study the use of in silica model to better understand and propose new markers of ovarian response to controlled ovarian stimulation before IVF.

METHODS

A systematic review and in silica model using bioinformatics. After the selection of 103 papers from a systematic review process, we performed a GRADE qualification of all included papers for evidence-based quality evaluation. We included 57 genes in the silica model using a functional protein network interaction. Moreover, the construction of protein-protein interaction network was done importing these results to Cytoscape. Therefore, a cluster analysis using MCODE was done, which was exported to a plugin BINGO to determine Gene Ontology. A p value of < 0.05 was considered significant, using a Bonferroni correction test.

RESULTS

In silica model was robust, presenting an ovulation-related gene network with 87 nodes (genes) and 348 edges (interactions between the genes). Related to the network centralities, the network has a betweenness mean value = 102.54; closeness mean = 0.007; and degree mean = 8.0. Moreover, the gene with a higher betweenness was PTPN1. Genes with the higher closeness were SRD5A1 and HSD17B3, and the gene with the lowest closeness was GDF9. Finally, the gene with a higher degree value was UBB; this gene participates in the regulation of TP53 activity pathway.

CONCLUSIONS

This systematic review demonstrated that we cannot use any genetic marker before controlled ovarian stimulation for IVF. Moreover, in silica model is a useful tool for understanding and finding new markers for an IVF individualization.

PROSPERO

CRD42020197185.

A common variant of the pregnancy-associated plasma protein-A (PAPPA) gene encodes a protein with reduced proteolytic activity towards IGF-binding proteins

Pregnancy-associated plasma protein-A (PAPP-A) is a key regulator of insulin-like growth factor (IGF) bioactivity, by releasing the IGFs from their corresponding IGF-binding proteins (IGFBPs). The minor allele of the single nucleotide polymorphism (SNP), rs7020782 (serine < tyrosine), in PAPPA has previously been associated with recurrent pregnancy loss as well as with significant reduced levels of PAPP-A protein in human ovarian follicles. The aim of the present study was to reveal a possible functional effect of the rs7020782 SNP in PAPPA by comparing recombinant PAPP-A proteins from transfected human embryonic kidney 293 T cells. The proteolytic cleavage of IGFBP-4 was shown to be affected by the rs7020782 SNP in PAPPA, showing a significantly reduced cleavage rate for the serine variant compared to the tyrosine variant (p-value < 0.001). The serine variant also showed a trend towards reduced cleavage rates, that was not significant, towards IGFBP-2 and IGFBP-5 compared to the tyrosine variant. No differences were found when analysing cell surface binding, complex formation between PAPP-A and STC2 or proMBP, nor when analysing STC1 inhibition of PAPP-A-mediated IGFBP-4 cleavage. Regulation of IGF bioactivity in reproductive tissues is important and the rs7020782 SNP in PAPPA may disturb this regulation by altering the specific activity of PAPP-A.

Genome-wide interactions between FSH and insulin-like growth factors in the regulation of human granulosa cell differentiation

Study question

Is the genome-wide response of human cumulus cells to FSH and insulin-like growth factors (IGFs) comparable to the response observed in undifferentiated granulosa cells (GCs)?

Summary answer

FSH actions in human cumulus cells mimic those observed in preantral undifferentiated GCs from laboratory animals, and approximately half of the regulated genes are dependent on the simultaneous activation of the IGF1 receptor (IGF1R).

What is known already

Animal studies have shown that FSH and the IGFs system are required for follicle growth and maturation. In humans, IGF levels in the follicular fluid correlate with patients' responses to IVF protocols. The main targets of FSH and IGFs in the ovary are the GCs; however, the genomic mechanisms involved in the response of GCs to these hormones are unknown.

Study design, size, duration

Human cumulus cells isolated from IVF patients were cultured for 48 h in serum-free media in the presence of vehicle, FSH, IGF1R inhibitor or their combination.

Participants/materials, setting, methods

Discarded cumulus cells were donated to research by reproductive-aged women undergoing IVF due to non-ovarian etiologies of infertility at a university-affiliated clinic. The effect of FSH and/or IGF1R inhibition on cumulus cell function was evaluated using Affymetrix microarrays, quantitative PCR, western blot, promoter assays and hormone level measurements.

Main results and the role of chance

The findings demonstrate that human cumulus cells from IVF patients respond to FSH with the expression of genes known to be markers of the preantral to preovulatory differentiation of GCs. These results also demonstrate that ~50% of FSH-regulated genes require IGF1R activity and suggest that several aspects of follicle growth are coordinately regulated by FSH and IGFs in humans. This novel approach will allow for future mechanistic and molecular studies on the regulation of human follicle maturation.

Large scale data

Data set can be accessed at Gene Expression Omnibus number GSE86427.

Limitations, reasons for caution

Experiments were performed using primary human cumulus cells. This may not represent the response of intact follicles.

Wider implications of the findings

Understanding the mechanisms involved in the regulation of GC differentiation by FSH and IGF in humans will contribute to improving treatments for infertility.

Study funding/competing interest(s)

The project was financed by the National Instituted of Health grant number R56HD086054 and R01HD057110 (C.S.). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. We have no competing interests to declare.

DHEA supplementation positively affects spontaneous pregnancies in women with diminished ovarian function

The aim of this article is to describe unexpected spontaneous pregnancies in poor responder patients with long-term infertility, when treated with dehydroepiandrosterone (DHEA) supplementation prior to in vitro fertilization (IVF). Our evaluation was carried out in two groups of women. The first group included 39 young women with <40 years, all treated with DHEA because of a previous poor response. The second group included 38 women over 40 years who received DHEA supplementation. Controls for latter group were 24 comparable women who had not been treated with DHEA before the first IVF cycle to evaluate the spontaneous pregnancy rate during preparation to IVF. Three tablets daily of 25 mg micronized DHEA were administered for at least 12 weeks before starting a long stimulation protocol for IVF. Surprisingly, spontaneous pregnancy rate significantly increased after DHEA treatment, allowing to achieve 10 spontaneous pregnancies and 9 spontaneous ongoing pregnancies among young poor responders. Pregnancy rate and ongoing pregnancy rate obtained before starting the IVF cycle were also significantly higher in older women treated with DHEA than in the control group: 21.05% and 13.15% and 4.1% and 0, respectively. Our results show that DHEA supplementation improves the ovarian function in poor responders and in women over 40 years, suggesting that this molecule alone can raise fecundity and fertility treatment success in women with poor prognosis for pregnancy.

The value of growth hormone supplements in ART for poor ovarian responders

Recently, three meta-analyses have concluded that cotreatment with GH improves assisted reproduction outcome in poor controlled ovarian stimulation responders. Although generally GH supplements did not increase controlled ovarian stimulation response or number of oocytes, the supplements improved pregnancy and live-birth rates-thus speaking for an effect on oocyte quality.

Dehydroepiandrosterone (DHEA) supplementation in diminished ovarian reserve (DOR)

BACKGROUND

With infertility populations in the developed world rapidly aging, treatment of diminished ovarian reserve (DOR) assumes increasing clinical importance. Dehydroepiandrosterone (DHEA) has been reported to improve pregnancy chances with DOR, and is now utilized by approximately one third of all IVF centers world-wide. Increasing DHEA utilization and publication of a first prospectively randomized trial now warrants a systematic review.

METHODS

PubMed, Cochrane and Ovid Medline were searched between 1995 and 2010 under the following strategy: [<dehydroepiandrosterone or DHEA or androgens or testosterone > and <ovarian reserve or diminished ovarian reserve or ovarian function >]. Bibliographies of relevant publications were further explored for additional relevant citations. Since only one randomized study has been published, publications, independent of evidence levels and quality assessment, were reviewed.

RESULTS

Current best available evidence suggests that DHEA improves ovarian function, increases pregnancy chances and, by reducing aneuploidy, lowers miscarriage rates. DHEA over time also appears to objectively improve ovarian reserve. Recent animal data support androgens in promoting preantral follicle growth and reduction in follicle atresia.

DISCUSSION

Improvement of oocyte/embryo quality with DHEA supplementation potentially suggests a new concept of ovarian aging, where ovarian environments, but not oocytes themselves, age. DHEA may, thus, represent a first agent beneficially affecting aging ovarian environments. Others can be expected to follow.

Aromatase gene (CYP19A1) variants, female infertility and ovarian stimulation outcome: a preliminary report

Progress has been made towards ascertaining the genetic predictors of ovarian stimulation in IVF. Aromatase cytochrome P450, encoded by the CYP19A1 gene, catalyses a key step in ovarian oestrogen biosynthesis. Hence, the aromatase gene is an attractive candidate for genetic studies. This study aimed to examine the genetic influences of CYP19A1 TCT trinucleotide insertion/deletion (Ins/Del) and (TTTA)(n) microsatellite intronic polymorphisms on ovarian stimulation outcome and aetiology of female infertility. IVF patients (n = 152) underwent ovarian stimulation according to recombinant FSH and gonadotrophin releasing hormone antagonist protocol. Del/Del homozygous patients with shorter TTTA repeats exhibited decreased ovarian FSH sensitivity in ovarian stimulation, which may reflect variations in aromatase gene expression during early antral follicle development. Accordingly, this study demonstrates correlations between Del allele and shorter (TTTA)(n) repeat sizes with smaller ovaries (r = -0.70, P = 0.047) and fewer antral follicles (r = 0.21, P = 0.018) on days 3-5 of spontaneous menstrual cycle, respectively. Furthermore, Del variation linked with low-repeat-number (TTTA)(n) alleles are involved in enhanced genetic susceptibility to unexplained infertility (adjusted OR = 4.33, P = 0.039) and endometriosis (r = -0.88, P = 0.026), which corroborates evidence on the overlapping patient profiles of ovarian dysfunction in both types of female infertility.

The role of IGF1 in the in vivo production of bovine embryos from superovulated donors

IGF1 plays an important role in bovine follicular growth, acquisition of oocyte competence and embryo viability. Current data also indicate a critical role for IGF1 in both the ovarian response and the embryo yield following the superovulatory treatments. IGF1 can have either positive or negative effects on embryo viability which is related to the concentration of IGF1 induced by superovulation treatment. These effects impact either on oocyte competence or directly on the embryo. Concentrations in the physiological range appear to result in the production of higher quality embryos, mainly due to the mitogenic and the anti-apoptotic activities of IGF1. However, high superovulatory responses are associated with decreased embryo viability and a concomitant increase in apoptosis. Studies in mice suggest that this increase in apoptosis is related to the downregulation of the IGF1 receptor in the embryo associated with high IGF1 concentrations. Strategies capable of controlling the IGF1 concentrations could be one approach to improve superovulation responses. A range of possible approaches for research within the IGF system in gonadotrophin-stimulated cattle is discussed in this review, including the possible use of superovulated female cattle as an alternative animal experimental model for research on reproductive disorders in humans associated with abnormal IGF1 concentrations.

Evaluation of the relationship between follicular fluid oxidative stress, ovarian hormones, and response to gonadotropin stimulation

OBJECTIVE

To investigate the relationship between oxidative stress and the underlying causes of infertility, preovulatory ovarian hormones, and ovarian response to gonadotropin stimulation in patients undergoing assisted reproductive techniques.

DESIGN

Prospective, cross-sectional study.

SETTING

Assisted conception unit, university hospital.

PATIENT(S)

One hundred thirty women presenting with infertility, of the following types: male factor (n = 56), unexplained (n = 36), tubal factor (n = 16), polycystic ovary syndrome (n = 15), and endometriosis (n = 7).

INTERVENTION(S)

Follicular fluid (FF) and peripheral blood samples were collected at oocyte retrieval.

MAIN OUTCOME MEASURE(S)

Blood and FF samples were analyzed for inhibin A, inhibin B, activin A, anti-Müllerian hormone, and E(2) by using ELISA. Total antioxidant capacity (TAC) was measured in plasma and FF by using a calorimetric microplate assay.

RESULT(S)

There was no significant relationship between plasma or FF TAC and the underlying etiology of infertility. There was a statistically significant positive association between FF E(2) levels and TAC (r = 0.26). Higher antral follicle count, delta E(2) (day 3 E(2) minus day 2 E(2)), preovulatory serum anti-Müllerian hormone, inhibin B, and E(2) were associated with good ovarian response, whereas higher FF E(2) was associated with a statistically significant poor response. No significant direct relationship was observed between TAC and ovarian response as well as between TAC or any of the parameters measured and pregnancy outcome.

CONCLUSION(S)

Oxidative stress has an impact on the production of granulosa cell steroid hormones, in particular E(2), which is an important predictor of ovarian response. The positive association between FF E(2) and total antioxidant capacity suggests that E(2) may play a role in the ovarian antioxidant-oxidant balance.