P–293 Ovarian endometriomas are heterogenous for the steroidogenic function and the expression of estrogen and progesterone receptors

Study question

Do all ovarian endometriomas have steroidogenic function and express estrogen and progesterone receptors?

Summary answer

No, they are heterogenous for the steroidogenic function and the expression of the estrogen and progesterone receptors.

What is known already

Excessive ectopic estrogen production and up-regulation of estrogen receptor- β, which drives inflammation together with aberrant progesterone signaling leading to impaired decidualization and establishment of ectopic endometrial implants together with down-regulated progesterone receptor (PR) expression are the cardinal molecular features of the disease. However, several fundamental questions still remain to be answered as to whether all ovarian endometriomas carry these molecular aberrations and are steroidogenically active; and if so, the amount of sex steroids they produce correlate with the level of expression of steroidogenic enzymes. We aimed to address these questions in the current study.

Study design, size, duration

A molecular research study on the surgical specimens collected between April 2020 and December 2020. Seven histopathologically confirmed benign endometriotic cyst capsules obtained from the patients undergoing laparoscopic excision of unilateral ovarian endometriomas without deep infiltrating endometriosis during early follicular phase were used in the study.

Participants/materials, setting, methods

The mean age±SD (range) of the patients were 32.8±4.9 (30–39). The mean endometrioma size was 5±1.2cm (5–7.5 cm). The samples were cut into equal size pieces of 0.5x0.5cm size and cultured for one day to measure their E2and P4production; and analyzed for the expression of steroidogenic enzymes with quantitative immunoblotting and for the expression of FSH-R, ER and PR with real-time qRT-PCR methods. Luteinized granulosa cells and ovarian cortex were set as references.

Main results and the role of chance

StAR expression was consistently observed in all samples. However, we noticed significant discrepancies among the samples regarding their steroidogenic function and the expression of aromatase and 3 β-HSD enzymes. E2 production exhibited significant variation (from 5 to 1177pg/mL) from sample to sample despite comparable levels of aromatase expression. ER- βup-regulation as a cardinal molecular feature of endometriosis, was observed in all but one samples (1.46 to 5.48 folds, p < 0.0001). However, its expression level did not correlate with either aromatase expression or the amount of E2 the samples produced. A similar phenomenon was observed in P4 arm of steroidogenesis. Even though 3 β-HSD was expressed by all but one samples detectable amount of P4 was produced only by two samples (up to 15ng/mL). PR expression was down-regulated only in two samples (0.3 to 0.07 folds, p < 0.0001), and significantly up-regulated in the other samples (1.2 to 4.7 folds, p < 0.001). No correlation was found among the samples regarding the expression of PR, 3 β-HSD and P4 output. FSH-R was detected in all samples at the levels comparable to ovarian cortex but its expression level did not show any correlation with ER, aromatase expression and E2 production.

Limitations, reasons for caution

These results need to be confirmed in studies with larger sample size and different types of endometriotic lesions.

Wider implications of the findings: The regulation of steroidogenic activity of endometriomas cannot simply be explained by the expression level of the steroidogenic enzymes, underscoring the importance of other mechanisms that post-translationally regulate their enzymatic activity and metabolism of estrogen and progesterone. PR is not always down-regulated and FSH-R is commonly up-regulated in ovarian endometriomas.

Trial registration number

Not applicable

P–660 Impact of elevated late-follicular phase serum estrogen and progesterone levels on blastocyst utilization and cumulative live birth rates in freeze-all cycles

Study question

Does elevated late-follicular phase estrogen and progesterone levels have an impact on blastocyst utilization and/or cumulative live birth rates in freeze-all cycles?

Summary answer

High estrogen or progesterone on the day of ovulation trigger is associated with poor blastocyst utilization but comparable cumulative live birth rates in freeze-all cycles.

What is known already

Several studies suggest impaired clinical outcome in cycles with high estrogen (>3500 pg/ml) or progesterone (>1.5 ng/ml) levels. However, these data were derived from cycles where top-quality embryo(s) were transferred in the fresh cycle and surplus embryos were frozen. These findings might be confounded by alterations in endometrial receptivity. Freeze-all cycles might provide a better model to assess the impact of high late-follicular estrogen or progesterone levels on laboratory and clinical outcome.

Study design, size, duration

We performed a retrospective cohort study of all IVF cycles (n = 712) between 2016 and 2018 where the entire cohort of embryos was cryopreserved at the blastocyst stage. After excluding cases with <4 oocytes or preimplantation genetic test, the study group comprised 459 women who had 699 frozen-thawed embryo transfer cycles.

Participants/materials, setting, methods

Women were classified into four groups by the indication for freeze-all strategy as elevated progesterone (high P, n = 61), high estrogen (high E, n = 224), elective freezing (elective, n = 114) and tubal-endometrial pathologies (TEP, n = 60). The primary outcome was the cumulative live birth rate in subsequent thaw-transfer cycles and the secondary outcome was the blastocyst utilization rate. Groups were compared using ANOVA and Cox regression analyses to adjust for confounding variables.

Main results and the role of chance

The mean age of the study group was 32.8 ± 5.3 years, total number of oocytes and cryopreserved blastocysts were 15.0±7.6 and 4.2±3.0, respectively. The high-E group was younger (31.5 ± 5.2 years) and had higher peak E2 levels (4078.9 ± 588.4 pg/ml), number of oocytes (19.7 ± 7.0), cryopreserved embryos (5.3 ± 3.3) and transfer cycles (2.3 ± 1.4) than the other groups. Blastocyst utilization rate was significantly lower (40.4%) compared to elective freezing (53.6%) and TEP groups (55.7%) (both p = 0.001). The high-P group had higher peak progesterone levels (2.1 ± 0.5 ng/ml, p = 0.001), number of oocytes (14.0 ± 5.2) and frozen embryos (4.1 ± 3.5) compared to elective and TEP groups (both p = 0.04). Blastocyst utilization rate was lower (45.7%) than elective freezing and TEP groups but the difference lacked statistical significance (p = 0.33 and p = 0.21, respectively). Cumulative live birth rates were 42.6% in high-P, 59.8% in high-E, 44.7% in elective freezing and 46.7% in TEP groups. Significant predictors of cumulative live birth were female age (aHR: 0.97, 95%CI:0.95–0.99, p = 0.02) and number of frozen blastocysts (aHR:1.05, 95%CI:1.01–1.10), p = 0.02). When adjusted for these confounders, the cumulative live birth rate was not associated with high-E (aHR: 0.86, 95%CI:0.56–1.31) or high-P (aHR: 0.76,95%CI:0.44–1.32).

Limitations, reasons for caution

This was a retrospective study with small sample size performed at a single fertility center, which may limit the generalizability of our findings.

Wider implications of the findings: While lower blastocyst utilization rates are observed in women high late-follicular estradiol or progesterone levels, cumulative live birth rates in subsequent thaw-transfer cycles were not impaired. However, unfavorable outcome parameters observed in women with elevated progesterone deserve further research.

Trial registration number

Not applicable

P–664 Bone morphogenetic protein–7 (BMP–7) reduces E2 and P4 production of human luteinized granulosa cells by down-regulating the expression of the steroidogenic enzymes StAR and 3B-HSD

Study question

What is the biological role of BMP–7 on the granulosa cells after luteinization?

Summary answer

BMP–7 down regulates the steroidogenic enzymes and reduces E2 and P4 output of luteinized granulosa cells.

What is known already

BMP–7 is a member of TGF-B super family that is mainly produced by theca cells in the ovary. It promotes the transition of primordials into primary follicles, and the growth and preantral and antral follicles, and inhibits progesterone (P4) production during FSH-induced growth phase of Graafian follicles (luteinization inhibitor). However, limited data is available regarding the role of this hormone on the molecular luteal characteristics of granulosa cells after ovulation and luteinization processes. We therefore aimed to address this issue in the current study.

Study design, size, duration

A basic science study on the corpus luteum biology

Participants/materials, setting, methods

Human luteal granulosa cells were obtained from 10 normo-responder IVF patients undergoing ovarian stimulation with rec-FSH and GnRH antagonist protocol and cultured with recombinant forms of BMP–7, hCG and activin-A for 24h. The presence of cognate receptors for these hormones were validated using RT-PCR. The expression of the steroidogenic enzymes were analyzed with quantitative immunoblotting, real-time RT-PCR and confocal microscopy. E2 and P4 production of the cells were measured using ECLIA method.

Main results and the role of chance

BMP–7 significantly down-regulated the expression of StAR and 3b-HSD in immunoblotting and confocal images and caused a substantial decrease in P4 production in the luteal GCs in a dose dependent manner. It did not cause any notable change in aromatase expression, however E2 output declined in parallel with P4 due to the reduced expression of StAR, which is the rate limiting enzyme in steroidogenesis. hCG significantly up-regulated StAR and 3b-HSD expression and enhanced P4 output whereas activin-A did the opposite effect. Viability assay with Yo-PRO–1 uptake assay did not reveal any significant differences in the viability of the cells before and after treatment with these hormones.

Limitations, reasons for caution

In-vitro findings requires validation using in-vivo models.

Wider implications of the findings: Reversal of luteinization and down-regulation of steroidogenesis with BMP–7 and other hormones with similar actions warrant further investigation to test their in-vivo effects in order to develop new strategies against ovarian hyperstimulation syndrome (OHSS).

Trial registration number

Not applicable

Simulation of transmission electron microscope images of biological specimens

We present a new approach to simulate electron cryo-microscope images of biological specimens. The framework for simulation consists of two parts; the first is a phantom generator that generates a model of a specimen suitable for simulation, the second is a transmission electron microscope simulator. The phantom generator calculates the scattering potential of an atomic structure in aqueous buffer and allows the user to define the distribution of molecules in the simulated image. The simulator includes a well defined electron-specimen interaction model based on the scalar Schrödinger equation, the contrast transfer function for optics, and a noise model that includes shot noise as well as detector noise including detector blurring. To enable optimal performance, the simulation framework also includes a calibration protocol for setting simulation parameters. To test the accuracy of the new framework for simulation, we compare simulated images to experimental images recorded of the Tobacco Mosaic Virus (TMV) in vitreous ice. The simulated and experimental images show good agreement with respect to contrast variations depending on dose and defocus. Furthermore, random fluctuations present in experimental and simulated images exhibit similar statistical properties. The simulator has been designed to provide a platform for development of new instrumentation and image processing procedures in single particle electron microscopy, two-dimensional crystallography and electron tomography with well documented protocols and an open source code into which new improvements and extensions are easily incorporated.

Molecular cryo-electron tomography of vitreous tissue sections: current challenges

Electron tomography of vitreous tissue sections (tissue TOVIS) allows the study of the three-dimensional structure of molecular complexes in a near-native cellular context. Its usage is, however, limited by an unfortunate combination of noisy and incomplete data, by a technically demanding sample preparation procedure, and by a disposition for specimen degradation during data collection. Here we outline some major challenges as experienced from the application of TOVIS to human skin. We further consider a number of practical measures as well as theoretical approaches for its future development.

Stem cells and reproductive medicine

For decades it has remained as a central dogma in dogma in reproductive biology that female mammals are born with a set non-renewable number of germ cells in the ovary. Recent revolutionary studies challenged this dogma by showing postnatal oogenesis in the adult ovary. In this review article the formation of primordial germ cells (PGC), the precursors of adult gametocytes beginning from their specification to their migration to prospective gonads will be reviewed with a special emphasis on stem cells studies that obtained gametocytes from germ and non germline stem cells.

A novel xenograft model to test the ovarian toxicity of chemotherapy agents in women

19504

Background: Many chemotherapeutic agents, especially of alkylating family, alter fertility in premenopausal females (1). While the impact of well-established agents such as cyclophosphamide (Cy) on fertility is well known (2), data are not available for newer agents. Moreover it is not practically possible to determine the individual ovarian-toxicity of each drug and the cellular mechanism of this damage from clinical trials.Thus our specific aim was to develop a xenograft model to characterize the impact of chemotherapy agents on human ovary. Methods: Ovarian pieces of 2x2 mm from 24 wk old abortuses were xenografted subcutaneously to immunodeficient mice (SCID) (n=52). At this gestational age ovarian histology is simiar to young females. Half of the animals received a single dose of 200 mg/kg of Cy intraperitoneally 14 days after the xenografting, while the other half received saline. Grafts were recovered from the control and treated mice 12, 24, 48, and 72h after the Cy injection (n=6–7 per time point), and serially sectioned for primordial follicle counts. Apoptosis was assessed with TUNEL assay. PECAM-1 staining, as well as intra-vital fluorescein conjugated lectin and Evans blue labeling were performed to assess microvasculature by confocal microscopy. All experiments were performed in triplicate. Results: While there was only 12 % loss 12h following the treatment compared to controls (p>0.05), the follicle loss significantly increased at 24h (53%, p<0.01) and peaked at 48h (93 %, p<0.0001), and reduced at 72h (70 %, p<0.001). TUNEL staining peaked at 12h, earlier than the follicle loss; then decreased at 24h and 48h, and faded at 72h. Less than 1% of follicles were TUNEL positive in controls. Xenograft vasculature was similar to non-xenografted tissue indicating that the ex vivo tissue drug delivery was similar to the in vivo delivery. Conclusions: A single injection of a typical dose of Cy can result in the loss of up to 93 % of ovarian reserve in a human ovarian xenograft model, consistent with the data from clinical trials. Fetal ovarian xenografting is a promising model to characterize the gonadotoxic effects of current and emerging cancer drugs without a need for lengthy clinical studies. 1. J Clin Oncol. 2006;24:2917–31 2. Hum Reprod Update. 2004;10:251–66.

No significant financial relationships to disclose.

Correlation between maternal thyroid function tests and endothelin in preeclampsia-eclampsia

OBJECTIVE

To investigate the relationship between results of maternal thyroid function tests and endothelin levels in preeclamptic or eclamptic women.

METHODS

Thyroid hormones, TSH, and endothelin were measured in plasma or serum from 37 proteinuric, preeclamptic or eclamptic women and 20 normotensive, nonlaboring, pregnant women. Subjects were subdivided into four groups according to hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome and birth weights of infants with respect to gestational age.

RESULTS

A significant decrease in concentrations of total thyroxine (T4) (13.76+/-1.84 microg/dL versus 10.00+/-1.48 microg/dL, P < .05), total triiodothyronine (T3) (180.58+/-30.84 ng/dL versus 141.16+/-27.31 ng/dL, P < .01), free T4 (1.45+/-0.27 ng/dL versus 1.10+/-0.21 ng/dL, P < .01) and free T3 (3.32+/-0.56 pg/mL versus 2.41+/-0.60 pg/mL, P < .01) and a significant increase in TSH (1.55+/-0.89 microIU/mL versus 2.96 +/-1.07 microIU/mL, P < .05) and endothelin (2.31+/-0.61 pg/mL versus 6.11+/-1.41 pg/mL, P < .001) levels were observed in the preeclamptic-eclamptic group compared with the normotensive group. Also, women without HELLP syndrome and without small-for-gestational-age infants had elevated levels of thyroid hormones and decreased levels of TSH and endothelin compared with other subgroups, but stastical significance was reached only in total T4 (P < .05), TSH (P < .05), and endothelin (P < .001). Birth weights of infants born to preeclamptic or eclamptic women correlated positively with total T4 (P < .01) and total T3 (P < .01) and negatively with TSH (P < .01) levels. A more significant negative correlation was found in preeclamptic-eclamptics (P < .001) between birth weight and endothelin levels than in control subjects (P < .05). Endothelin levels in preeclamptic or eclamptic women correlated negatively with total T4 (P < .01), total T3 (P < .05), free T4 (P < .05), and free T3 (P < .05) and positively with TSH levels (P < .01) compared with control subjects.

CONCLUSION

Moderate decreases in thyroid hormones with concomitant increases in TSH levels in maternal serum correlated with severity of preeclampsia or eclampsia and high levels of endothelin. Changes in results of thyroid function tests induced by preeclampsia or eclampsia might be consequences of the dysfunction in the hypothalamic-pituitary-thyroid axis, secondary to the disease itself.

Hyaluronic acid plus heparin for improved efficacy in prevention of adhesion formation in rat uterine horn model

OBJECTIVE

To determine the effectiveness of hyaluronic acid (HA) and heparin [unfractioned heparin (UH) or low molecular weight heparin (LMWH)] combination in reducing adhesion formation in a rat uterine horn model.

STUDY DESIGN

Prospective, randomized, comparative study in a rat model was done in Surgical Research Laboratory, Erciyes University. A standard lesion was created by unipolar electrocautery in 120 uterine horns of total 60 female Wistar-Albino rats. Animals were then randomly assigned into four groups, each consisting of 15 animals: (1) control, no adjuvant given; (2) HA, 1 ml of 0.4% solution given onto each horn preoperatively; (3) HA, 1 ml of 0.4% solution given preoperatively plus 1 ml of UH given postoperatively; (4) HA, 1 ml of 0.4% solution given before injury plus 1 ml of LMWH given after injury. A second-look laparotomy was performed two weeks after surgery. The number of horns with adhesion was determined and a scoring system applied.

RESULT(S)

The number of horns without adhesion formation was significantly higher in HA plus UH (P<0.05) and HA plus LMWH (P<0.01) groups compared to control group. The extent, severity and total scores of adhesion formation were also found to be significantly reduced in other groups when compared to control group. Combination of HA plus UH and HA plus LMWH significantly reduced all adhesion scores compared to HA alone. But a direct comparison of the ability of HA plus UH versus HA plus LMWH in reducing adhesion scores in the rat uterine horn yielded an insignificant difference.

CONCLUSION

Administration of HA before injury followed by UH or LMWH given after injury has been documented to improve the efficacy of HA alone in reducing adhesion formation.