Relationship of ovarian stimulation response with vascular endothelial growth factor and degree of granulosa cell apoptosis

Plasma-derived from human umbilical cord blood restores ovarian function and improves serum reproductive hormones levels in mice with premature ovarian insufficiency (POI) through cytokines and growth factors

Premature ovarian insufficiency (POI) patients experience a decline in ovarian function and a reduction in serum reproductive hormones, leading to a significant impact on the outcomes of assisted reproductive technology. Despite the absence of an effective clinical treatment to restore fertility in POI patients, recent research has indicated that cord blood plasma (CBP) derived from human umbilical cord blood (hUCB) may offer therapeutic benefits for various degenerative diseases. The primary aim of this study is to explore approaches for enhancing ovarian function and serum reproductive hormones through the administration of CBP in a murine model. Initially, hUCB was utilized to obtain CBP (CBP), which was subsequently analyzed for cytokine and growth factor profiles in comparison to adult blood plasma (ABP) by use of flow cytometry. Subsequently, POI mouse models were established through the induction of 4-vinylcyclohexene diepoxide, followed by the injection of CBP into the tail. At 7, 14, and 21 days posttreatment, mouse ovaries and blood were collected, and their estrus cycle, body weight, and ovarian weights were evaluated using precise electronic balance. Finally, ovarian morphology and follicle number were assessed through HE staining, while serum levels of anti-Müllerian hormone (AMH), estradiol (E2) and follicle-stimulating hormone (FSH) were determined by ELISA. Our study revealed that individuals with CBP exhibited significantly lower concentrations of proinflammatory cytokines, including IL-β (p < 0.01) and IL-2 (p < 0.05), while displaying elevated levels of anti-inflammatory cytokines and chemokines, such as IL-2, IL-4, IL-6, IL-8, IL-12P70, IL-17A, IP-10, interferon-γ, and tumor necrosis factor-α (p < 0.01). Furthermore, CBP demonstrated remarkably higher levels of growth factors, including transforming growth factor-β1, vascular endothelial growth factor, and insulin-like growth factor-1 (p < 0.01) than ABP. Notably, our investigation also revealed that CBP restored the content of serum reproductive hormones, such as AMH, E2, and FSH (p < 0.05), and increased the number of primordial and primary follicles (p < 0.01) and decreased the number of luteal and atretic follicles (p < 0.01) in vivo. Our findings suggested that CBP-secreted cytokines and growth factors could be restored POI ovarian function, enhanced serum reproductive hormones and rescued follicular development in vivo. These findings further support the potential of CBP as a promising strategy in clinical applications for POI related infertility.

Effects of vascular endothelial growth factor (VEGF) on the viability, apoptosis and steroidogenesis of yak (Bos grunniens) granulosa cells

Vascular endothelial growth factor (VEGF) is crucial for follicle development through the regulation of granulosa cell (GC) function in some mammals, but its mechanism is unclear in yak (Bos grunniens). Therefore, the objectives of this study were to investigate the effects of VEGF on the viability, apoptosis and steroidogenesis of yak GCs. First, we investigated the localization of VEGF and its receptor (VEGFR2) in yak ovaries by immunohistochemistry analysis and evaluated the effect of culture medium containing different VEGF concentrations and culture times on the viability of yak GCs by Cell Counting Kit-8. Then, optimal treatment with 20 ng/mL VEGF for 24 h was selected to analyze the effects of this compound on intracellular reactive oxygen species levels by DCFH-DA kit, cell cycle and apoptosis by flow cytometry, steroidogenesis by ELISA kit and the expression of the related genes by RT‒qPCR. The results showed that VEGF and VEGFR2 were highly coexpressed in GCs and theca cells. GCs cultured in medium containing 20 ng/mL VEGF for 24 h significantly improved cell viability, decreased ROS production, promoted the transition from G1 phase to S phase (P < 0.05), increased the expression of the CCND1 (P < 0.05), CCNE1, CDK2, CDK4, and PCNA genes (P < 0.01) and decreased the expression of the P53 gene (P < 0.05). This treatment significantly reduced GC apoptosis (P < 0.05) by promoting the expression of BCL2 and GDF9 (P < 0.01) and inhibiting the expression of BAX and CASPASE3 (P < 0.05). VEGF promoted progesterone secretion (P < 0.05) accompanied by increased expression of HSD3B, StAR and CYP11A1 (P < 0.05). Taken together, our findings highlight the beneficial influence exerted by VEGF in improving GC viability and reducing ROS production and the apoptosis rate through the modulation of related gene expression.

Glyphosate effects on the female reproductive systems: a systematic review

Glyphosate-based herbicides (GBHs) are organophosphate pesticides, which interrupt the chemicals involved in the endocrine system and cause lifelong disorders in women's reproductive system. The current study was designed to systematically evaluate the association between GBH exposure and the female reproductive tract. According to PRISMA Guidelines, the systematic review was performed, searching online databases, including Google Scholar, Web of Science, PubMed, and Scopus, throughout April 2020. Studies with Rodent, lamb, and fish or exposed to GBH to affect the female reproductive system were selected. All studies were in the English language. Two investigators independently assessed the articles. The first author's name, publication date, animal model, age, sample size, gender, dose, duration, and route of exposure and outcomes were extracted from each publication. The present review summarizes 14 publications on uterus alterations and oocytes, histological changes ovary, and assessed mRNA expression, protein expression, serum levels progesterone, and estrogen and intracellular Reaction Oxygen Species (ROS) in rodents, fish, and lamb exposed to GHB exposure. Most of the studies reported histological changes in ovarian and uterus tissue, alterations in serum levels, and increased oxidative stress level following exposure to GBH. Additionally, due to alterations in the reproductive systems (e.g., histomorphological changes, reduction of the mature follicles, higher atretic follicles, and interstitial fibrosis), it seems the GBH-induced female these alterations are both dose- and time-dependent. The present findings support an association between GBH exposure and female reproductive system diseases. However, more studies are needed to identify the mechanisms disrupting the effects of GBH and their underlying mechanisms. Considering the current literature, it is recommended that further investigations be focused on the possible effects of various pesticides on the human reproductive system.

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.

The distribution and expression of vascular endothelial growth factor A (VEGFA) during follicular development and atresia in the pig

The involvement of vascular endothelial growth factor A (VEGFA) in ovarian physiological processes has been widely reported, but the location and role of VEGFA during follicular atresia remain unknown. This study investigated the distribution and expression of VEGFA during porcine follicular development and atresia. Pig ovaries were obtained, individual medium-sized (3-5mm in diameter) antral follicles were separated and classified into healthy, early atretic or progressively atretic groups. Immunobiology and quantitative techniques were used to investigate the varied follicular distribution of VEGFA at both the morphological and molecular level. The results indicated that VEGFA protein expression peaked in tertiary follicles, mostly distributed in the thecal and inner granulosa layers, during follicular development while VEGFA mRNA was mainly expressed in the inner granulosa layers. Additionally, healthy antral follicles showed a significantly higher expression of VEGFA than atretic follicles in both theca and granulosa cells. Knockdown of VEGFA using siRNA revealed an antiapoptosis effect of VEGFA in cultured pig granulosa cells. Our results increase the knowledge of VEGFA functions in follicles.

Human embryonic stem cell-derived mesenchymal stem cells improved premature ovarian failure

BACKGROUND

Premature ovarian failure (POF) affects many adult women less than 40 years of age and leads to infertility. According to previous reports, various tissue-specific stem cells can restore ovarian function and folliculogenesis in mice with chemotherapy-induced POF. Human embryonic stem cells (ES) provide an alternative source for mesenchymal stem cells (MSCs) because of their similarities in phenotype and immunomodulatory and anti-inflammatory characteristics. Embryonic stem cell-derived mesenchymal stem cells (ES-MSCs) are attractive candidates for regenerative medicine because of their high proliferation and lack of barriers for harvesting tissue-specific MSCs. However, possible therapeutic effects and underlying mechanisms of transplanted ES-MSCs on cyclophosphamide and busulfan-induced mouse ovarian damage have not been evaluated.

AIM

To evaluate ES-MSCs vs bone marrow-derived mesenchymal stem cells (BM-MSCs) in restoring ovarian function in a mouse model of chemotherapy-induced premature ovarian failure.

METHODS

Female mice received intraperitoneal injections of different doses of cyclophosphamide and busulfan to induce POF. Either human ES-MSCs or BM-MSCs were transplanted into these mice. Ten days after the mice were injected with cyclophosphamide and busulfan and 4 wk after transplantation of the ES-MSCs and/or BM-MSCs, we evaluated body weight, estrous cyclicity, follicle-stimulating hormone and estradiol hormone concentrations and follicle count were used to evaluate the POF model and cell transplantation. Moreover, terminal deoxynucleotidyl transferase mediated 2-deoxyuridine 5-triphosphate nick end labeling, real-time PCR, Western blot analysis and immunohistochemistry and mating was used to evaluate cell transplantation. Enzyme-linked immunosorbent assay was used to analyze vascular endothelial growth factor, insulin-like growth factor 2 and hepatocyte growth factor levels in ES-MSC condition medium in order to investigate the mechanisms that underlie their function.

RESULTS

The human ES-MSCs significantly restored hormone secretion, survival rate and reproductive function in POF mice, which was similar to the results obtained with BM-MSCs. Gene expression analysis and the terminal deoxynucleotidyl transferase mediated 2-deoxyuridine 5-triphosphate nick end labeling assay results indicated that the ES-MSCs and/or BM-MSCs reduced apoptosis in the follicles. Notably, the transplanted mice generated new offspring. The results of different analyses showed increases in antiapoptotic and trophic proteins and genes.

CONCLUSION

These results suggested that transplantation of human ES-MSCs were similar to BM-MSCs in that they could restore the structure of the injured ovarian tissue and its function in chemotherapy-induced damaged POF mice and rescue fertility. The possible mechanisms of human ES-MSC were related to promotion of follicular development, ovarian secretion, fertility via a paracrine effect and ovarian cell survival.

Transition to the ovulatory season in mares: An investigation of antral follicle receptor gene expression in vivo

The inability to obtain in vivo samples of antral follicle wall layers without removing the ovaries or sacrificing the animals has limited more in-depth studies on folliculogenesis. In this study, a novel ultrasound-guided follicle wall biopsy (FWB) technique was used to obtain in vivo follicle wall layers and follicular fluid samples of growing antral follicles. The expression of proliferative, hormonal, angiogenic, and pro-/antiapoptotic receptors and proteins in the follicular wall among three follicle classes were compared during the spring transitional anovulatory (SAN) and spring ovulatory (SOV) seasons in mares. The main findings observed in the granulosa, theca interna, and/or all follicle layers during the SOV season compared with the SAN season were (a) small-sized follicles (10-14 mm) had greater epidermal growth factor receptor (EGFR) and Bcl-2 expression; (b) medium-sized follicles during the expected deviation/selection diameter (20-24 mm) had greater expression of EGFR, Ki-67, luteinizing hormone receptor (LHR), and Bcl-2; and (c) dominant follicles (30-34 mm) had greater EGFR, Ki-67, vascular endothelial growth factor, LHR, and Bcl-2 expression. Estradiol related receptor alpha expression and intrafollicular estradiol concentration increased, along with an increase in follicle diameter in both seasons. In this study, the application of the FWB technique allowed a direct comparison of different receptors' expression among follicles in different stages of development and between two seasons using the same individuals, without jeopardizing their ovarian function. The successful utilization of the FWB technique and the mare as an experimental animal offer a great combination for future folliculogenesis studies on mechanisms of follicle selection, development, and ovulation in different species, including women.

Toxic effects and possible mechanisms following malathion exposure in porcine granulosa cells

Malathion is a wide spectrum organophosphorothionate insecticide that is frequently found in drinking water, food and foodstuffs. Ovarian granulosa cells modulate oogenesis by providing metabolic nutrients to oocytes. They can decide the fate of folliculogenesis and oocyte maturation by supplying regulatory cues that help in reproduction. However, little is known about the underlying mechanisms of malathion as a reproductive toxicant in porcine granulosa cells. In the present study, we found that malathion has obvious toxic effects on cultured porcine granulosa cells in a dose-dependent manner. Malathion exposure resulted in significantly increased oxidative stress levels and DNA damage response, which was measured by the mRNA expression levels of homologous recombination (HR) pathway and non-homologous end-joining (NHEJ) pathway-related genes. Subsequently, it was found that malathion exposure could induce apoptosis and autophagy by qRT-PCR and fluorescence intensity analysis. In conclusion, malathion is a reproductive toxicant by inhibiting granulosa cell proliferation by multiple pathways connected to oxidative stress, DNA damage, apoptosis and autophagy.

Human umbilical cord mesenchymal stem cells improve the reserve function of perimenopausal ovary via a paracrine mechanism

Background

Human umbilical cord mesenchymal stem cells (hUCMSCs) are a type of pluripotent stem cell which are isolated from the umbilical cord of newborns. hUCMSCs have great therapeutic potential. We designed this experimental study in order to investigate whether the transplantation of hUCMSCs can improve the ovarian reserve function of perimenopausal rats and delay ovarian senescence.

Method

We selected naturally aging rats confirmed by vaginal smears as models of perimenopausal rats, divided into the control group and the treatment group, and selected young fertile female rats as normal controls. hUCMSCs were transplanted into rats of the treatment group through tail veins. Enzyme-linked immunosorbent assay (ELISA) detected serum levels of sex hormones, H&E staining showed ovarian tissue structure and allowed follicle counting, immunohistochemistry and western blot analysis revealed ovarian expression of hepatocyte growth factor (HGF), vascular endothelial cell growth factor (VEGF), and insulin-like growth factor-1 (IGF-1), polymerase chain reaction (PCR) and western blot analysis revealed hUCMSCs expression of HGF, VEGF, and IGF-1.

Results

At time points of 14, 21, and 28 days after hUCMSCs transplantation, estradiol (E₂) and anti-Müllerian hormone (AMH) increased while follicle-stimulating hormone (FSH) decreased; ovarian structure improved and follicle number increased; ovarian expression of HGF, VEGF, and IGF-1 protein elevated significantly. Meanwhile, PCR and western blot analysis indicated hUCMSCs have the capacity of secreting HGF, VEGF, and IGF-1 cytokines.

Conclusions

Our results suggest that hUCMSCs can promote ovarian expression of HGF, VEGF, and IGF-1 through secreting those cytokines, resulting in improving ovarian reserve function and withstanding ovarian senescence.

Molecular and cellular mechanisms for the regulation of ovarian follicular function in cows

Ovary is an important organ that houses the oocytes (reproductive cell). Oocyte growth depends on the function of follicular cells such as the granulosa and theca cells. Two-cell two gonadotropin systems are associated with oocyte growth and follicular cell functions. In addition to these systems, it is also known that several growth factors regulate oocyte growth and follicular cell functions. Vascular endothelial growth factor (VEGF) is involved in thecal vasculature during follicular development and the suppression of granulosa cell apoptosis. Metabolic factors such as insulin, growth hormone (GH) and insulin-like growth factor 1 (IGF-1) also play critical roles in the process of follicular development and growth. These factors are associated not only with follicular development, but also with follicular cell function. Steroid hormones (estrogens, androgens, and progestins) that are secreted from follicular cells influence the function of the female genital tract and its affect the susceptibility to bacterial infection. This review covers our current understanding of the mechanisms by which gonadotrophins and/or steroid hormones regulate the growth factors in the follicular cells of the bovine ovary. In addition, this review describes the effect of endotoxin on the function of follicular cells.

LH supplementation in down-regulated women undergoing assisted reproduction with baseline low serum LH levels

AIM

The aim of our study is to evaluate the effect of recombinant-human LH supplementation on ovarian response and pregnancy outcome, during ovarian stimulation, in down-regulated women with baseline low serum LH levels undergoing assisted reproductive technology.

STUDY DESIGN

A prospective randomized study performed with 80 women, with serum LH levels 50.5 IU/l on cycle Day 6 of stimulation. Group-A (40): 14-days after down-regulation with leuprorelin, ovarian stimulation was initiated only with r-FSH 225 IU. Group-B (40): at the same time stimulation was initiated with rFSH 225 IU associated with rLH 75 UI on cycle Day 6 of stimulation.

RESULTS

Serum-E2 levels on the hCG-day administration were significantly reduced in the Group-A. FF-VEGF levels were higher in Group-A. We did not find significant differences in the number of retrieved oocytes. The quality of oocytes proved to be higher and more significant from a statistical point of view in Group-B. The number of embryos obtained and transferred, the pregnancy rate lower in Group-A.

CONCLUSIONS

In our study, it was shown that LH supplementation seems to have a beneficial effect on the maturity and fertilizability of oocyte. Lower FF VEGF levels, found in Group B, could be an indication of a lower apoptosis rate in human cumulus cells after administration of LH. We can affirm that LH-supplementation is beneficial in patients who show asignificant serum LH suppression during the receptorial down-regulation

Follicular oestradiol and VEGF after GnRH antagonists or GnRH agonists in women with PCOS

The aim of this study was to determine whether follicular oestradiol and vascular endothelial growth factor (VEGF) concentrations in women with polycystic ovarian syndrome (PCOS) differ according to the use of gonadotrophin-releasing hormone (GnRH) antagonists or GnRH agonists. Furthermore, the effect of follicular oestradiol and VEGF concentrations on oocyte and embryo quality was investigated. In this prospective clinical study, 20 women with PCOS undergoing intracytoplasmic sperm injection for male factor infertility were included using a GnRH antagonist or a GnRH agonist protocol. In each follicle, oestradiol and VEGF concentrations were determined. In the GnRH antagonist group 254 follicles and in the GnRH agonist group 245 follicles, were aspirated. Fewer metaphase II (MII) and more immature and degenerative oocytes were registered in the GnRH antagonist group. Follicular oestradiol and VEGF were lower in the GnRH antagonist group (P = 0.014 and P < 0.001, respectively). Moreover, higher oestradiol concentrations were related to embryos of higher quality (P = 0.037). It is concluded that GnRH antagonists decrease follicular oestradiol and VEGF concentrations and the number of retrieved MII oocytes in women with PCOS.

Human granulosa-lutein cell in vitro production of progesterone, inhibin A, inhibin B, and activin A are dependent on follicular size and not the presence of the oocyte

OBJECTIVE

To investigate inhibin A, inhibin B, activin A, and P production by cultured granulosa cells (GCs) and what relationship this hormone production has to fertility.

DESIGN

Luteinized GCs from individual follicles were cultured, and inhibin A, inhibin B, activin A, and P production were measured by ELISA at 24 and 72 hours.

SETTING

Research laboratory and university hospital.

PATIENT(S)

Fifteen women who undertook an IVF-ICSI program, yielding 58 follicles.

INTERVENTION(S)

Individual follicular aspiration and preparation of GCs for culture.

MAIN OUTCOME MEASURE(S)

Inhibin A, inhibin B, activin A, and P production; oocyte retrieval; and fertility outcome.

RESULT(S)

Inhibin A, inhibin B, and P continued to be secreted by GCs in vitro, and activin A levels were detected only marginally in 56% of cultures. The rate of production also was dependent on the size of follicle from which the GCs originated but not on oocyte presence or ability to fertilize. Granulosa cell stimulation with hCG had no effect on inhibin A but increased P and decreased inhibin B production.

CONCLUSION(S)

A marked effect of luteal differentiation appears to be the inhibition of inhibin B production in response to hCG stimulation. Luteinized GC function, with respect to inhibins, activin A, and P production, was not influenced by the presence or absence of an oocyte and did not correlate with fertility outcome. However, follicle size did influence rates of local hormone production.

Vascular endothelial growth factor (VEGF) suppresses ovarian granulosa cell apoptosis in vitro

Vascular endothelial growth factor (VEGF) inhibits the follicular atresia that resulted from granulosa cell apoptosis in the mammalian ovary. In the present study, we examined the effect of VEGF on granulosa cell apoptosis. Here, we report that VEGF suppresses granulosa cell apoptosis by inhibiting the release of caspase-activated DNase (CAD) without being associated with the mitochondrial pathway. VEGF did not stimulate or inhibit Bcl-xL and Bax, respectively, in granulosa cells. In addition, VEGF did not suppress the expression of active caspase-3, whereas follicle-stimulating hormone (FSH) inhibited caspase-3. However, VEGF and FSH suppressed the release of CAD resulting from the disintegration of the CAD-ICAD complex. These results demonstrate that VEGF is a strong survival factor for granulosa cell apoptosis (ovarian follicular atresia).

Significance of ovarian macrophages in the follicular aspirates from ART patients

PURPOSE

To evaluate the percentages of macrophages present in granulosa cells (GC) cultures from patients with different responses to the hyperstimulation, in relation to the percentages of apoptotic cells (ApC), as well as to the release of cytokines.

METHODS

We studied 42 patients: 12 Hyporesponders, (with < or =4 follicles), 15 Normoresponders, (5-14 follicles), and 15 Hyperresponders, (> or =15 follicles). In GC cultures percentages of macrophages and ApC were counted and, in the conditioned media, cytokines were measured.

RESULTS

Percentages of macrophages were significantly higher in GC cultures from Hyporesponders compared with Hyperresponders patients. Also, the percentages of ApC cells were the highest in Hyporesponders. On the contrary, cytokines concentrations were the lowest in this group.

CONCLUSIONS

The low ovarian response is probably due to the decreased angiogenesis, which in turn produces increased apoptosis and decreased production of cytokines. The increased percentage of macrophages could be related to increased frequency of apoptotic cells.

Follicular fluid vascular endothelial growth factor and tumour necrosis factor α concentrations in patients with endometriosis undergoing ICSI

The aim of this study was to investigate follicular fluid vascular endothelial growth factor (VEGF) and tumour necrosis factor alpha (TNFalpha) concentrations in endometriosis, and their effect on the outcome of intracytoplasmic sperm injection (ICSI). A prospective study was performed among patients who had either a laparoscopic diagnosis of endometriosis (n = 48) or who had normal laparoscopic findings with unexplained infertility (n = 43). The number of gonadotrophin units, peak oestradiol concentrations, number of oocytes retrieved, fertilization, cleavage and pregnancy rates, and number of embryos transferred, were the main outcome measurements. There was no difference in these parameters between the two study groups. Significantly higher concentrations of VEGF were found in the endometriosis group (P = 0.031), but there was no difference in TNFalpha concentrations. No relationship was found between VEGF and TNFalpha concentrations and ICSI outcome. Despite a higher concentration of intrafollicular VEGF in the endometriosis group, it was concluded that this parameter had no predictive value with respect to ICSI outcome. In addition, intrafollicular TNFalpha concentrations were not different in the endometriosis group and there was no relationship between VEGF or TNFalpha concentrations and the outcomes measured.

Gonadotropin-releasing hormone antagonists increase follicular fluid insulin-like growth factor-I and vascular endothelial growth factor during ovarian stimulation cycles

The aim of the present study was to investigate the effect of gonadotropin-releasing hormone (GnRH) antagonists (GnRH-ant) on follicular fluid (FF) insulin-like growth factor-I (IGF-I) and FF vascular endothelial growth factor (VEGF) levels. Sixty women undergoing assisted reproduction were randomized and assigned to two different GnRH analog regimens: GnRH agonist (GnRH-a) and GnRH-ant. FF VEGF and FF IGF-I concentrations were significantly increased in the patients treated with GnRH-ant (p < 0.001). In the same patients we observed a statistically significant reduction in serum luteinizing hormone (LH) and estradiol (E2) levels (p < 0.001 and p < 0.05, respectively), FF E2 and FF androstenedione levels (p < 0.05 and p < 0.001, respectively), as well as a reduction in the number of pregnancies although this was not statistically significant. In the GnRH-ant group, FF VEGF levels were positively correlated with FF IGF-I levels, and both were negatively correlated with serum LH levels. The increase in FF IGF-I and FF VEGF levels in women treated with GnRH-ant could be explained by a deleterious follicular environment in response to profound suppression of LH and E2 levels.

Follicular fluid vascular endothelial growth factor concentrations are increased during GnRH antagonist/FSH ovarian stimulation cycles

BACKGROUND

The aim of this study was to investigate the effect of GnRH antagonists (GnRH-ant) on follicular fluid vascular endothelial growth factor (FF VEGF).

METHODS

Sixty women undergoing assisted reproduction were randomised (computer-generated randomisation list) and assigned to two different GnRH analogue regimens: GnRH agonist (GnRH-a) (Group A; n = 30) and GnRH-ant (Group B; n = 30).

RESULTS

Mean (+/-S.D.) FF VEGF concentrations were 1598+/-612 pg/mL and 2906+/-1558 pg/mL for Groups A and B, respectively (p < 0.001). In the women treated with GnRH-ant, we found a statistically significant reduction in serum LH levels (1.72+/-0.74 IU/L in Group A versus 0.93+/-0.43 IU/L in Group B, p < 0.001), in serum oestradiol (E2) levels (1562.1+/-410.7 pg/mL in Group A versus 1214.67+/-779.9 pg/mL in Group B, p < 0.05), in FF E2 levels (1146+/-593 ng/mL in Group A versus 621+/-435 ng/mL in Group B, p < 0.05), and in FF androstenedione levels (136+/-55 ng/mL in Group A versus 78+/-31 ng/mL in Group B, p < 0.001), as well as a reduction in the number of pregnancies, though not statistically significant (23.3% in Group A versus 16.6% in Group B).

CONCLUSION

The increase in FF VEGF levels in women treated with GnRH-ant might be explained by a suppression of LH and E2 levels.

Predictive value of cumulus cell apoptosis with regard to blastocyst development of corresponding gametes

OBJECTIVE

To test if a high degree of apoptosis in cumulus cells could indicate diminished oocyte quality and developmental competence.

DESIGN

Prospective analysis.

SETTING

Public hospital and university.

PATIENT(S)

Thirty seven women who gave written consent to participate in this study.

INTERVENTION(S)

Cumulus-oocyte complexes were denuded separately and the resulting cumulus cell suspensions were analyzed for presence of apoptosis using a terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling (TUNEL) assay detection kit.

MAIN OUTCOME MEASURE(S)

Percentage of apoptotic cumulus cells and blastocyst formation rate.

RESULT(S)

Younger patients (< or = 35 years) showed significantly fewer apoptotic cumulus cells than older ones. In all patients gamete maturity was shown to be highly correlated to the rate of apoptosis in cumulus cells. At zygote and cleavage stages (days 1 to 4) no morphologic features were related to the degree of programmed cell death. However, blastocyst development was predictable taking into account the percentage of apoptosis in associated somatic cells. In addition, there was a trend toward better quality blastocysts from follicles with a lower rate of apoptotic cells. No influence on pregnancy and implantation rate was observed.

CONCLUSION(S)

Apoptotic processes within follicles seem to impair oocyte maturation. Though not manifested in the morphologic appearance, gametes and embryos derived from cumulus complexes with no or minor apoptosis have an increased chance of giving rise to optimal blastocysts.

Vascular endothelial growth factor in the plasma, follicular fluid and granulosa cells of women with endometriosis submitted to in vitro fertilization--a pilot study

Vascular endothelial growth factor (VEGF), a potent angiogenic factor that is altered in endometriosis, supports the immunological mechanism involved in this disease. The aim of the present study was to assess VEGF concentration in the plasma, follicular fluid (FF) and culture medium (CM) of granulosa cells from patients with endometriosis submitted to in vitro fertilization (IVF). A case-control study was conducted on 14 patients with endometriosis and 14 women without endometriosis submitted to IVF. Peripheral blood samples were collected before and after administration of human chorionic gonadotropin (hCG), in addition to FF and CM samples. Plasma VEGF levels increased after hCG administration in women with endometriosis and in controls, but were significant only in controls. VEGF levels were lower in FF but were significantly increased in the CM of patients with endometriosis. There was no correlation between VEGF and age, response to ovarian stimulation, oocyte or embryo quality, and pregnancy result. The increase of VEGF levels after hCG in both groups demonstrated a positive effect of this hormone on VEGF. VEGF in the FF and CM presented opposite results in endometriosis, suggesting that granulosa cells may show a different behavior in vivo and in vitro.

Vascular endothelial growth factor and inhibin A in follicular fluid of infertile patients who underwent in vitro fertilization with a gonadotropin-releasing hormone antagonist

OBJECTIVE

To investigate the role of a gonadotropin-releasing hormone (GnRH) antagonist, minimal stimulation protocol, in the follicular fluid by measuring vascular endothelial growth factor (VEGF) and inhibin A.

DESIGN

A cross-sectional prospective study.

SETTING

Academic hospital.

PATIENT(S)

Seventy infertile patients submitted to in vitro fertilization (IVF).

INTERVENTION(S)

Patients were divided into two groups: group 1 (study) included 30 infertile patients subjected to IVF with a GnRH antagonist (minimal stimulation protocol); group 2 (control) included 40 infertile women who underwent natural-cycle IVF.

MAIN OUTCOME MEASURE(S)

Follicular fluid VEGF and inhibin A measurements.

RESULT(S)

The groups were comparable in terms of age, body mass index (BMI), and infertility characteristics. Moreover, follicular fluid VEGF and inhibin A concentrations (medians) were, respectively, 776 pg/ml (95% confidence interval [CI]: 775-1483) and 3,115 pg/mL (95% CI: 1,349-2,502) for group 1; 1,187.50 pg/mL (95% CI: 1,020-1,560) and 3,123.00 pg/mL (95% CI: 1,888-2,735) for group 2 (P>.05).

CONCLUSION(S)

We demonstrated that GnRH antagonist administration in infertile patients undergoing IVF did not alter the follicular fluid content of VEGF and inhibin A, and, probably, maturation and quality of oocytes as well. These results demonstrated the usefulness and safety of this drug on controlled ovarian stimulation (COS) protocols.

Direct injection of vascular endothelial growth factor into the ovary of mice promotes follicular development

OBJECTIVE

To investigate the effects of an ovarian injection of vascular endothelial growth factor (VEGF) on antral follicle development, neoangiogenesis, and apoptosis.

DESIGN

Controlled laboratory study.

SETTING

University-affiliated fertility center.

ANIMAL(S)

Balb/c female mice (n = 32) were studied.

INTERVENTION(S)

Mice were divided into four groups: control group (C) n = 6, no treatment; hyperstimulated group (HS), n = 8, ovaries were stimulated with 7.5 IU pregnant mare serum gonadotropin (PMSG) and 10 IU of hCG; VEGF group (V), n = 8, injected with 0.1 mL of VEGF (0.2 microg) in each ovary; V+HS, n = 8 injected with VEGF and 2 weeks later hyperstimulated.

MAIN OUTCOME MEASURE(S)

Number of antral and luteinized follicles, number of vessels, and percentage of Bcl-2-positive cells.

RESULT(S)

The number of antral follicles with VEGF was higher than in the C and HS groups (16.0 +/- 2.5 vs. 6.0 +/- 0.9 and 11.3 +/- 0.6, respectively, p<0.005). All treatments significantly increased the number of vessels (C: 5.0 +/- 0.5 vs. V: 20.0 +/- 4.8, p<0.005 and V+HS: 22.2 +/- 1.2, p<0.01), as well as increased Bcl-2-positive cells compared to controls (C: 0; V: 11.8 +/- 3.5, p<0.005; V+HS: 12.5 +/- 3.7, p<0.005).

CONCLUSION(S)

Our findings demonstrated that a direct injection of VEGF into the mouse ovary results in the development of an enhanced vascular network promoting follicular development and diminishing apoptosis.

Expression and localization of thrombospondin-1 and -2 and their cell-surface receptor, CD36, during rat follicular development and formation of the corpus luteum

Thrombospondin (TSP)-1 and -2 are extracellular matrix glycoproteins that are both antiangiogenic and important in regulating cellular development, differentiation, and function. To evaluate the expression of TSP in follicular and luteal development, ovarian cycles of Sprague-Dawley rats were synchronized and tissues collected daily at stages corresponding to the early antral, ovulatory, early luteal, and late luteal phases of the ovarian cycle. Immunohistochemistry and Western blot analyses demonstrated that TSP-1 protein and its receptor, CD36, were present in the early antral phase and were localized primarily to the granulosa cells of antral follicles. Both proteins were also present immediately after ovulation and were localized to the developing corpus luteum. Messenger RNA for TSP-1 showed a similar pattern, with expression at the early antral and ovulatory phases. Protein and mRNA expression for TSP-2 was relatively delayed compared to TSP-1, although TSP-2 also was expressed in granulosa cells. Both TSP-1 and -2 were increased in response to LH stimulation in vitro, whereas TSP-2 was suppressed by FSH. The temporal pattern of expression of TSP-1, -2, and CD36, which mirrors the active phases of angiogenesis in this experimental model, is compatible with a role for these proteins in the control of ovarian vascularization.