Expression, production, and secretion of vascular endothelial growth factor and interleukin-6 by granulosa cells is comparable in women with and without endometriosis

Endometriosis as a detrimental condition for granulosa cell steroidogenesis and development: From molecular alterations to clinical impact

Endometriosis is an estrogen-dependent chronic inflammatory condition that affects women in their reproductive period. Alterations in ovarian follicle morphology and function have been documented in affected women. The local intrafollicular environment has been as well examined by various groups. In the present review, we aimed to summarize the molecular evidence supporting the idea that endometriosis can negatively influence growth, steroidogenesis and the function of the granulosa cells (GCs). Reduced P450 aromatase expression, increased intracellular ROS generation and altered WNT signaling characterize the GCs of women with endometriosis. Clear evidence for an increased level of GC apoptosis has been provided in association with the downregulation of pro-survival factors. Other potentially negative effects include decreased progesterone production, locally decreased AMH production and lower inflammatory cytokine expression, although these have been only partially clarified. The possibility that endometriosis per se may influence IVF clinical results as a consequence of the detrimental impact on the local intrafollicular environment is also discussed.

Concentration of Glutathione and Expression of Glutathione Peroxidases 1 and 4 in Fresh Sperm Provide a Forecast of the Outcome of Cryopreservation of Human Spermatozoa

Oxidative stress imbalance potentially leads to damage of the structure of the cell and macromolecules such as plasma membrane components, proteins, and DNA. The plasma membrane of the sperm cell, which has high levels of polyunsaturated fatty acids, renders it particularly sensitive to free radical-mediated attacks. The freezing and subsequent thawing of sperm is a physically stressful process carried out during routine procedures in assisted reproduction techniques, which results in a highly variable and unpredictable reduction in the number of motile sperm cells. Subsequently, oxidative status can positively or negatively affect the motility, viability, and fertilizing capacity of thawed sperm. These effects are counteracted by various oxidative defense enzymes and anti-oxidants such as glutathione peroxidase isoforms GPx1 and GPx4, glutathione reductase (GR), and cellular glutathione (reduced) (GSH). In this way, oxidative status could represent a predictive marker of sperm quality following the freeze-thaw process. This study was based on 56 human sperm samples. We observed direct positive and negative relationships between the postthaw motile sperm recovery rate and GPx1 and GPx4 expression and activity, on the one hand, and GSH concentrations, on the other. No correlation was found between this recovery rate and GR or basic semen parameters. Predictive values clearly demonstrate that, among the molecules analyzed, the most accurate diagnoses result when analyses are conducted for GPx1 and GPx1 messenger RNA expression, GPx1 and GPx4 enzymatic activity, and GSH concentration. In conclusion, a reserve of glutathione, together with GPx expression, is necessary to eliminate free radicals using GSH or a like structural protein and seems to be essential for a good postthaw recovery. These molecules can be employed as indicators of postthaw sperm quality.

Development of a novel protocol for isolation and purification of human granulosa cells

PURPOSE

To develop an optimal method of isolation and purification of human granulosa cells from ovarian follicular fluid.

METHODS

Follicular fluid was collected from patients undergoing oocyte retrieval. A series of isolation and purification techniques was performed, involving density gradient centrifugation and use of different antibody-bead complexes.

RESULTS

The highest percent yield of live purified granulosa cells came from density gradient centrifugation using sucrose polymer followed by positive selection of granulosa cells using primary antibody to MISRII and secondary antibody coupled to iron oxide beads.

CONCLUSIONS

A novel protocol for granulosa cell purification has been developed yielding samples that are largely free of nondesirable cells. This protocol provides a purification solution, especially for patient samples that have significant RBC contamination.

Concentrations of receptor for advanced glycation end products, VEGF and CML in plasma, follicular fluid, and peritoneal fluid in women with and without endometriosis

The etiology and pathogenesis of endometriosis is largely unknown. It has been reported that advanced glycation end products-receptor for advanced glycation end products regulation relates to oxidative stress, inflammatory reaction, apoptosis, and angiogenesis through vascular endothelial growth factor activation. The purpose of this study was to examine whether advanced glycation end products-receptor for advanced glycation end products regulation contributes to the pathogenesis of endometriosis. Plasma, follicular, and peritoneal fluid samples were collected from women with or without endometriosis, and soluble receptor for advanced glycation end products, vascular endothelial growth factor and carboxymethyl lysine levels were measured by enzyme-linked immunosorbent assay. Vascular endothelial growth factor and soluble receptor for advanced glycation end products concentrations were similar in plasma; however, their concentrations in follicular fluid were significantly increased in endometriosis patients (soluble receptor for advanced glycation end products was 132 + 31 pg/mg of protein vs. 105 + 27 pg/mg; vascular endothelial growth factor was 70 + 3 pg/mg vs. 49 + 18 pg/mg, expressed as the mean + standard deviation). Increased soluble receptor for advanced glycation end products and vascular endothelial growth factor levels in a local environment suggest that the advanced glycation end products-receptor for advanced glycation end products may contribute to the pathogenesis of endometriosis.

Inhibition of vascular endothelial growth factor receptor signal transduction blocks follicle progression but does not necessarily disrupt vascular development in perinatal rat ovaries

We hypothesized that vascular endothelial growth factor A (VEGFA) angiogenic isoforms and their receptors, FLT1 and KDR, regulate follicular progression in the perinatal rat ovary. Each VEGFA angiogenic isoform has unique functions (based on its exons) that affect diffusibility, cell migration, branching, and development of large vessels. The Vegfa angiogenic isoforms (Vegfa_120, Vegfa_164, and Vegfa_188) were detected in developing rat ovaries, and quantitative RT-PCR determined that Vegfa_120 and Vegfa_164 mRNA was more abundant after birth, while Vegfa_188 mRNA was highest at Embryonic Day 16. VEGFA and its receptors were localized to pregranulosa and granulosa cells of all follicle stages and to theca cells of advanced-stage follicles. To determine the role of VEGFA in developing ovaries, Postnatal Day 3/4 rat ovaries were cultured with 8 muM VEGFR-TKI, a tyrosine kinase inhibitor that blocks FLT1 and KDR. Ovaries treated with VEGFR-TKI had vascular development reduced by 94% (P < 0.0001), with more primordial follicles (stage 0), fewer early primary, transitional, and secondary follicles (stages 1, 3, and 4, respectively), and greater total follicle numbers compared with control ovaries (P < 0.005). V1, an inhibitor specific for KDR, was utilized to determine the effects of only KDR inhibition. Treatment with 30 muM V1 had no effect on vascular density; however, treated ovaries had fewer early primary, transitional, and secondary follicles and more primary follicles (stage 2) compared with control ovaries (P < 0.05). We conclude that VEGFA may be involved in primordial follicle activation and in follicle maturation and survival, which are regulated through vascular-dependent and vascular-independent mechanisms.

KiSS-1 in the mammalian ovary: distribution of kisspeptin in human and marmoset and alterations in KiSS-1 mRNA levels in a rat model of ovulatory dysfunction

Kisspeptins, the products of the KiSS-1 gene acting via G protein-coupled receptor 54 (GPR54), have recently emerged as pivotal signals in the hypothalamic network triggering the preovulatory surge of gonadotropins and, hence, ovulation. Additional actions of kisspeptins at other levels of the hypothalamic-pituitary-ovarian axis have been suggested but remain to date scarcely studied. We report herein the pattern of expression of KiSS-1 and GPR54 in the human and nonhuman primate ovary and evaluate changes in ovarian KiSS-1 expression in a rat model of ovulatory dysfunction. KiSS-1 and GPR54 mRNAs were detected in human ovarian tissue and cultured granulosa-lutein cells. In good agreement, kisspeptin immunoreactivity was observed in cyclic human and marmoset ovaries, with prominent signals in the theca layer of growing follicles, corpora lutea, interstitial gland, and ovarian surface epithelium. GPR54 immunoreactivity was also found in human theca and luteal cells. Administration of indomethacin to cyclic female rats disturbed ovulation and resulted in a dramatic drop in ovarian KiSS-1, but not GPR54, cyclooxygenase-2 (COX-2), or progesterone receptor, mRNA levels at the time of ovulation; an effect mimicked by the selective COX-2 inhibitor NS398 and rescued by coadministration of PGE(2). Likewise, the stimulatory effect of human choriogonadotropin on ovarian KiSS-1 expression was partially blunted by indomethacin. In contrast, KiSS-1 mRNA levels remained unaltered in another model of ovulatory failure, i.e., the RU486-treated rat. In summary, we document for the first time the expression of KiSS-1/kisspeptin and GPR54 in the human and nonhuman primate ovary. In addition, we provide evidence for the ability of inhibitors of COX-2, known to disturb follicular rupture and ovulation, to selectively alter the expression of KiSS-1 gene in rat ovary. Altogether, our results are suggestive of a conserved role of local KiSS-1 in the direct control of ovarian functions in mammals.

Leuprolide acetate reduces both in vivo and in vitro ovarian steroidogenesis in infertile women undergoing assisted reproduction

Despite the probable inhibitory effects of GnRH analogues on ovarian steroidogenesis in vitro, their association with assisted reproduction protocols shows favorable results. This suggests that there are important differences in the behaviors of these drugs when administered in vivo versus in vitro. To clarify these differences, this study was designed to analyze the effect of leuprolide acetate (LA) on ovarian steroidogenesis in women undergoing In Vitro Fertilization (IVF). A prospective, randomized open label study was conducted on 14 women (26-35 years): seven receiving only gonadotrophins (Group 1) and seven receiving gonadotrophin plus LA at 1mg/day (Group 2). The LA in vivo effect was determined with serum and follicular fluid (FF) samples and via luteinized granulosa cell cultivation (GCC), where cells were obtained during oocyte retrieval after ovarian hyperstimulation. In vitro analysis was performed via addition of LA to GCC only for Group 1 (without LA) at progressively higher concentrations (0, 10(-12), 10(-9) and 10(-6)M). In vivo, the main observation was a reduction in androgen production in Group 2, represented by lower androstenedione production in FF (G1=6479+/-3458; G2=3021+/-1119 ng/ml; p=0.04) and a lower testosterone peak in GC at 96h (G1=0.64+/-0.12 ng/ml; G2=0.50+/-0.19 ng/ml; P=0.02), but a higher fertilization rate (G1=67%; G2=83%; p=0.009). In vitro, testosterone, estradiol and progesterone were also reduced by LA, even though this reduction occurred for progesterone only at the highest LA dosage (10(-6)M; 606.0+/-114.3 ng/ml versus 1524.0+/-246.5 ng/ml; p=0.02). Results show that LA reduces ovarian steroidogenesis in vivo by essentially inhibiting androgen synthesis; whereas, in vitro, ovarian steroidogenesis is reduced overall.

The gonadotropins: tissue-specific angiogenic factors?

The gonadotropins, whose members are human chorionic gonadotropin (hCG), lutenizing hormone (LH) and follicle-stimulating hormone (FSH) are a well characterized hormone family known to regulate reproductive functions in both females and males. Recent studies indicate that they can modulate the vascular system of reproductive organs. It was shown that gonadotropins not only influence the expression of vascular endothelial growth factor (VEGF) and both its receptors VEGFR-1 and -2, but also modulate other ubiquitously expressed angiogenic factors like the angiopoietins and their receptor Tie-2, basic fibroblast growth factor or placental-derived growth factor. Some recent data indicates a possible direct action of gonadotropins on endothelial cells. Thus, the gonadotropins act as tissue-specific angiogenic factors providing an optimal vascular supply during the menstrual cycle and early pregnancy in the female reproductive tract as well as in testis. In pathological conditions (e.g. preeclampsia, intrauterine growth restriction, ovarian hyperstimulation or endometriosis), these tightly regulated interactions between the gonadotropins and the ubiquitous angiogenic factors appear to be disturbed. The intent of this short manuscript is to review the current knowledge of the regulatory role of the gonadotropins in vasculo- and angiogenesis. We also review angiogenic actions of thyroid-stimulating hormone (TSH), a glycoprotein closely related to gonadotropins, which display strong gonodal actions.

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.

Vascular endothelial growth factor response to exogenous chorionic gonadotropic hormone in the luteal phase of women with a history of severe ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome (OHSS) is a severe complication of ovarian stimulation. No reliable test exists to predict the syndrome. The objective of the present prospective observational study was to examine vascular endothelial growth factor (VEGF) secretion after human chorionic gonadotropin (hCG) administration in the luteal phase of a spontaneous cycle of women with a history of severe OHSS. Five women with a history of severe OHSS were administered 250 mug recombinant hCG intravenously on day 21 of a spontaneous menstrual cycle. Plasma samples were collected at regular intervals from 15 min before hCG to 6 h thereafter and the free VEGF plasma concentrations were determined. Plasma levels of free VEGF remained at the lower detection limit of the assay throughout the observational period. Women with previous severe OHSS do not show a significant short-time response of VEGF secretion upon hCG administration. No evidence was found to support the notion that women inclined to develop a severe form of the syndrome after ovarian stimulation could possibly be identified by the VEGF short-time secretory response to exogenous hCG in the luteal phase of a spontaneous cycle.

How does endometriosis affect infertility?

Prospective and retrospective clinical trials suggest a decreased oocyte and embryo quality in women with endometriosis. Based on these observations, the authors described an altered intrafollicular milieu in endometriosis, which explains the bad quality oocytes and the resulting embryos with lower capacity to implant. Whether these changes affect the oocytes or are the consequence of genomic alterations manifested by biochemical and chromosomal differences in healthy women is an unresolved issue. If the effects of endometriosis on follicular development are nongenomic in origin, modulation of the process of folliculogenesis may be sufficient to treat the disease and cure infertility associated with endometriosis. A genomic defect needs specific genetic therapy, which currently is not available.

Serum concentrations of growth factors in women with and without endometriosis: the action of anti-endometriosis medicines

Endometriosis is a common gynecologic syndrome of unknown etiology and pathogenesis. Growth factors and inflammatory mediators produced by peritoneal leukocytes have recently been postulated to participate in the pathogenesis of endometriosis. Angiogenic factors released from peritoneal macrophages may also play a role in the development of this disease. In the present study, we investigate the soluble levels of vascular endothelial growth factor (VEGF), epidermal growth factor-receptor (EGF-R), granulocyte/macrophage-colony stimulating factor (GM-CSF), Insulin-like growth factor-1 (IGF-1) and interferon-gamma (IFN-gamma) in the serum of 28 women with and 20 without endometriosis. We also compared these levels before, during and after treatment with danazol and leuprorelin acetate depot, the two therapeutic regiments of choice concerning this disease. We found that only sVEGF levels were higher in women with endometriosis in comparison to controls (P < 0.001) while sEGF-R is not present. GM-CSF, IGF-1 and IFN-gamma soluble levels are not affected in either healthy or endometriotic subjects. The 6-month treatment with danazol decreased sVEGF levels (P < 0.02) and increased sEGF-R levels (P < 0.001). These observations support the view that VEGF may be associated with the disease process and that danazol may bring sVEGF levels to a normal threshold. However, future studies will be focused on the anti-angiogenic control of the action of VEGF in patients with endometriosis.

Influence of severe endometriosis on gene expression of vascular endothelial growth factor and interleukin-6 in granulosa cells from patients undergoing controlled ovarian hyperstimulation for in vitro fertilization-embryo transfer

OBJECTIVE

To evaluate how endometriosis affects expression of vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) in granulosa cells.

DESIGN

Prospective study.

SETTING

IVF-ET program at Osaka Medical College.

PATIENT(S)

Seventeen patients with revised American Fertility Society stage IV endometriosis and 17 patients with tubal infertility and no endometriosis.

INTERVENTION(S)

Granulosa cells obtained at oocyte retrieval were examined for VEGF and IL-6 gene expression.

MAIN OUTCOME MEASURE(S)

Serum E(2) and P levels at hCG administration, number of oocytes, fertilization rate, high-quality embryo rate, and pregnancy rate, and expression of VEGF and IL-6 genes.

RESULT(S)

Total hMG and FSH levels were statistically significantly higher in patients with endometriosis; however, the number of retrieved oocytes and the fertilization rate were lower compared with patients with tubal infertility. Serum E(2) levels and expression of VEGF in patients with tubal infertility were statistically significantly higher than those in patients with endometriosis. Interleukin-6 gene expression did not differ between the groups.

CONCLUSION(S)

In severe endometriosis, lower VEGF gene expression in granulosa cells may adversely affect oocyte development and maturation.

Human chorionic gonadotropin-induced ovarian hyperstimulation syndrome is associated with up-regulation of vascular endothelial growth factor

Ovarian hyperstimulation syndrome (OHSS), a life-threatening complication occurring in stimulated ovarian cycles, arises from treatment with gonadotropin for induction of follicular maturation in infertile women. Clinical characteristics of OHSS include ascites and pleural effusion induced by increased vascular permeability, where vascular endothelial growth factor (VEGF) was suspected to be the culprit. To test whether the effects of human CG (hCG) on the pathogenesis of OHSS were mediated through the VEGF produced by luteinized granulosa cells, we measured estradiol, VEGF, IGF-II levels in serum, and follicular fluid and analyzed their mRNA expression in luteinized granulosa cells obtained from 101 women (58 with OHSS and 43 controls) who underwent in vitro fertilization and embryo transfer. This study presents the first evidence that hCG up-regulated VEGF expression of granulosa cells in the OHSS, not the control groups, and that follicular VEGF worked through an autocrine mechanism using its kinase insert domain-containing receptor, not the fms-like tyrosine kinase receptor. We calculated total follicular production of VEGF, by multiplying follicular concentrations by follicular volumes, and verified that an increase in total follicular production of VEGF accounted for elevated serum levels of VEGF, which was associated with the development of OHSS. These findings demonstrate that through up-regulation of VEGF, hCG plays a significant role in the pathogenesis of OHSS.

Expression and function of 3beta hydroxisteroid dehydrogenase (3beta HSD) type II and corticosteroid binding globulin (CBG) in granulosa cells from ovaries of women with and without endometriosis

PURPOSE

To investigate the secretion of progesterone (P4) and corticosteroid binding globulin (CBG) by granulosa luteal cells (GC) as well as the mRNA levels of CBG and 3beta hydroxisteroid dehydrogenase (3beta HSD), in women with and without endometriosis in vivo and in vitro.

METHODS

Prospective study in a private, university-affiliated assisted reproduction unit, including women with severe endometriosis (n = 14) or without the disease (n = 20) undergoing in vitro fertilization/intracytoplasmic sperm injection and embryo transfer. GC were obtained from each follicle aspirated, pooled for each patient, and follicular and blood contaminating leukocytes depleted through immunomagnetic purification. Secreted P4 and CBG, and mRNA for both 3beta HSD and CBG were determined in vivo and in vitro using RIA and reverse transcription followed by competitive polymerase chain reaction (cRT-PCR).

RESULTS

The pattern of expression of 3beta HSD and CBG mRNAs in vivo and in vitro was similar in both groups. Also, GC from patients with endometriosis produced equal amounts of P4 and CBG than controls without the disease, either in freshly isolated cells or in 24-h cultures.

CONCLUSIONS

The GC function in terms of 3beta HSD and CBG mRNA expression and P4/CBG secretion does not seem to be altered in patients with endometriosis in comparison with those without this condition.