Cytokines in the human ovary: presence in follicular fluid and correlation with leukotriene B4

The follicular fluid adipocytokine milieu could serve as a prediction tool for fertility treatment outcomes

RESEARCH QUESTION

Can the adipocytokine milieu of the follicular niche improve the ability to predict treatment outcomes in infertile patients?

DESIGN

Follicular fluid samples from overweight patients were analysed and compared with samples from matched normal-weight patients. Concentrations of adiponectin, chemerin, C-reactive protein, interleukin-6 (IL-6), IL-10, IL-18, insulin, leptin, prolactin, resistin, tumour necrosis factor alpha (TNF-α) and bone morphogenetic protein-15 (BMP-15) were assessed by multiple magnetic bead immunoassay (MMBI) and enzyme-linked immunosorbent assay and correlated with fertility treatment outcomes.

RESULTS

Analysis of samples from 22 overweight and 22 normal-weight patients demonstrated that TNF-α can predict oocyte maturation rate. When stratified by body mass index (BMI), IL-10 emerges as a better predictor of oocyte maturation in normal-weight patients. Prolactin was a negative predictor for fertilization rate in the full cohort, and this prediction power was lost upon stratification. No adipocytokines were predictive of blastulation rate, and only age remained predictive. BMP-15 was a strong predictor of high-quality blastulation in the full cohort, more so in the normal-weight population.

CONCLUSIONS

The adipocytokine milieu of the follicular fluid provides a snapshot of the growing oocyte's environment and can help predict fertility treatment outcomes, fine-tuning understanding of the dysregulation caused by increasing BMI. Inflammatory cytokines can predict oocyte maturation; prolactin, oocyte competence; and BMP-15, high-quality blastulation. Further analysis of these findings with a larger sample size and assessing individual oocytes will help shed more light on the clinical significance of these findings.

Messenger RNA and protein expression of tumor necrosis factor α and its receptors in human follicular granulosa cells

To evaluate the concentration of tumor necrosis factor α (TNF-α) and its soluble receptors (sTNFR I and II) in serum and follicular fluid (FF) at the time of oocyte retrieval and to detect expression of TNF-α and its receptors by luteinized granulosa cells (GCs). In a cross-sectional study and through an in vitro fertilization-intracytoplasmic sperm injection (IVF-ICSI) program, 81 women undergoing oocyte retrieval were recruited. Serum and FF were obtained from 81 women. GCs were pooled from 20 patients (from six different days of oocyte retrievals, 5-16 follicles per patient). TNF-α and its soluble receptors concentration were determined by enzyme-linked immunosorbent assay and also their expression by immune cytochemistry and reverse-transcription polymerase chain reaction analysis. The median TNF-α concentration in serum was 4.06 pg/ml (interquartile range [IQR], 3.71-6.14) and significantly higher than that in FF with 3.50 pg/ml (IQR, 3.05-5.01), p < 0.001. The sTNFR I and II levels in serum were lower and higher than FF, respectively. The TNF-α levels in serum and FF of good responders were higher than low responders (p = 0.017 and 0.021, respectively). TNF-α cut-off level for low responders versus good responders was 4.174 pg/ml in serum with a pregnancy rate of 25.8% and 40% for below and above of this level, respectively (p = 0.19). For FF, the cut-off value was 3.89 pg/ml. TNF-α and its receptors were expressed by GCs. The presence of TNF-α and its soluble receptors in serum and FF and their expression by GCs suggest an important role for this cytokine in ovarian function.

Herbal fertility treatments used in North America from colonial times to 1900, and their potential for improving the success rate of assisted reproductive technology

This paper serves to fill a gap in the literature regarding evidence for the use of botanical remedies in the promotion of fertility. It examines the botanical remedies that were used in North America (1492-1900) for all stages of reproduction from preconception to birth, and discusses their potential for future use with present-day infertility treatments. Each medicinal plant discussed in this paper is assessed using an ethnomedicinal methodology that entails examining the published ethnobotanical, phytochemical and pharmacological data. A few clinical trials have shown that there is potential for medicinal plants to improve the success rate of assisted reproductive technology (ART) treatment if used in an integrated manner, similar to the integrated use of traditional Chinese medicine with ART treatment. For example, research has shown that older women who become pregnant have a high miscarriage rate, and this is one area that complementary and alternative medicines can address.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Metabolite Profiling in the Pursuit of Biomarkers for IVF Outcome: The Case for Metabolomics Studies

Background. This paper presents the literature on biomarkers of in vitro fertilisation (IVF) outcome, demonstrating the progression of these studies towards metabolite profiling, specifically metabolomics. The need for more, and improved, metabolomics studies in the field of assisted conception is discussed. Methods. Searches were performed on ISI Web of Knowledge SM for literature associated with biomarkers of oocyte and embryo quality, and biomarkers of IVF outcome in embryo culture medium, follicular fluid (FF), and blood plasma in female mammals. Results. Metabolomics in the field of female reproduction is still in its infancy. Metabolomics investigations of embryo culture medium for embryo selection have been the most common, but only within the last five years. Only in 2012 has the first metabolomics investigation of FF for biomarkers of oocyte quality been reported. The only metabolomics studies of human blood plasma in this context have been aimed at identifying women with polycystic ovary syndrome (PCOS). Conclusions. Metabolomics is becoming more established in the field of assisted conception, but the studies performed so far have been preliminary and not all potential applications have yet been explored. With further improved metabolomics studies, the possibility of identifying a method for predicting IVF outcome may become a reality.

Follicular fluid content and oocyte quality: from single biochemical markers to metabolomics

The assessment of oocyte quality in human in vitro fertilization (IVF) is getting increasing attention from embryologists. Oocyte selection and the identification of the best oocytes, in fact, would help to limit embryo overproduction and to improve the results of oocyte cryostorage programs. Follicular fluid (FF) is easily available during oocyte pick-up and theorically represents an optimal source on non-invasive biochemical predictors of oocyte quality. Unfortunately, however, the studies aiming to find a good molecular predictor of oocyte quality in FF were not able to identify substances that could be used as reliable markers of oocyte competence to fertilization, embryo development and pregnancy. In the last years, a well definite trend toward passing from the research of single molecular markers to more complex techniques that study all metabolites of FF has been observed. The metabolomic approach is a powerful tool to study biochemical predictors of oocyte quality in FF, but its application in this area is still at the beginning. This review provides an overview of the current knowledge about the biochemical predictors of oocyte quality in FF, describing both the results coming from studies on single biochemical markers and those deriving from the most recent studies of metabolomics.

Identification of a C1q family member associated with cortical granules and follicular cell apoptosis in Carassius auratus gibelio

C1q family proteins with C1q domain have been reported in vertebrates, but their biological roles are currently unknown. In this study, a C1q-like factor, designated Carassius auratus gibelio ovary-specific C1q-like factor (CagOC1q-like), was identified as a cortical granules component. Immunofluorescence localization revealed that the C1q family member was specifically expressed in follicular epithelial cells, and associated with cortical granules in fully grown oocytes. Moreover, it was discharged to the perivitelline space and egg envelope upon fertilization. As it is the first identified C1q family member that is expressed in follicular cells that surround oocyte, CagOC1q-like was applied to detection of follicular cell apoptosis and deletion. The entire cytological process of follicular cell apoptosis and deletion was clearly seen from double visualizations of follicular cells with CagOC1q-like immunofluorescence and apoptotic follicular cells labeled by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) during oocyte maturation and ovulation.

Follicular fluid levels of interleukin-10 and interferon-gamma do not predict outcome of assisted reproductive technologies

PROBLEM

Follicular fluid (FF) and surrounding tissue contains various lymphocytes that synthesize different cytokines. The other sources of cytokines are ovarian somatic cells. FF provides microenvironment for the oocyte and contains immunological factors for the regulation of its development. Changes in expression and concentrations of certain cytokines can influence oocyte and embryo quality, resulting in a reduced ability to implant. Some data shows that follicular environment depends on infertility indication. The purpose of our study was to investigate whether cytokines interleukin-10 (IL-10) and interferon-gamma (IFN-gamma) are released in the human FF and also to evaluate impact of those cytokines on fertilization rate, cleavage rate, embryo quality, and pregnancy rate.

METHODS OF STUDY

Couples treated by assisted reproductive technologies were selected for this study. A total of 121 patients participated in the study. Until cytokine detection samples of FF were stored at -20 degrees C. In vitro fertilization or intracytoplasmic sperm injection procedure was used depending on the indication. After 72 hr, on the day of transfer, embryo morphology was evaluated. Embryo transfer based on embryo morphology was performed. Commercial enzyme-linked immunosorbent assay kit from Diaclone, France was used for the quantitative determination of human IL-10 and IFN-gamma concentrations in FF. Analysis of the results was performed using spss 12.0.

RESULTS

One hundred and twenty-one FF samples were tested for IL-10 and IFN-gamma. IFN-gamma and IL-10 were detected in 14 (11.6%) and 108 (89.3%) FF samples, respectively (range 0.9-31.1 pg/mL for IFN-gamma and 0.7-10.8 pg/mL for IL-10). There was no significant correlation between infertility indication, fertilization rate, cleavage rate, and concentrations of the follicular cytokines. Similarly, IL-10 concentrations did not differ significantly in different age groups and did not alter pregnancy rate.

CONCLUSION

Our study showed that IFN-gamma and IL-10 are not suitable markers in predicting outcome of assisted reproductive technologies.

Novel follicular fluid factors influencing oocyte developmental potential in IVF: a review

The aim of IVF centres today is to obtain high quality, developmentally competent embryos, and thus increase live birth rates. Apoptosis in the patient's follicles in among the factors that will determine IVF outcome. Follicular fluid constitutes an important microenvironment, containing apoptotic factors and others, which influence oocyte growth. The sFas-sFas ligand system is present in the follicular fluid and may play a role in preventing oocyte aresia during folliculogenesis. Levels of the anti-apoptotic molecule sFas may be related positively to oocyte maturation and negatively to fertilization and embryo quality. Reactive oxygen species exert a toxic effect when found in high concentrations in the follicular fluid, whereas in low concentrations they might be indispensable for pregnancy and therefore serve as a potential marker for successful IVF outcome. Nitric oxide plays a dual role; in some cells promoting and in others inhibiting apoptosis. Nitric oxide production is stimulated by TNF-alpha, so the latter is also implicated in the apoptotic process. Hyaluronan, a disaccharide, whose functions have not been fully elucidated, is a valuable predictor of oocyte fertilization. Gelatinases are responsible for remodelling during follicular atresia. In conclusion, a number of factors found in the follicular fluid, some involved in apoptosis, can infulence assisted reproduction.

Identification of a novel C1q family member in color crucian carp (Carassius auratus) ovary

Potential roles of C1q/tumor necrosis factor (TNF) superfamily proteins have been observed in vertebrate oogenesis and oocyte maturation, but no ovary-specific member has been identified so far. In this study, we have cloned and identified a novel member of C1q family with a C1q domain in the C-terminal from fully grown oocyte cDNA library of color crucian carp and demonstrated that the gene might be specifically expressed in ovary and therefore designated as Carassius auratus ovary-specific C1q-like factor, CaOC1q-like factor. It encodes a 213 amino acid protein with a 17 amino acid signal peptide. There is only one protein band of about 24.5 kDa in the extracts from phase I to phase IV oocytes, but two positive protein bands are detected in the extracts of mature eggs and fertilized eggs. Furthermore, the mobility shift of the smaller target protein band cannot be eliminated by phosphatase treatment, but the larger protein band increases its mobility on the gel after phosphatase treatment, suggesting that the larger protein might be a phosphorylated form. Immunofluorescence localization indicates that the CaOC1q-like proteins localize in cytoplasm, cytoplasm membrane and egg envelope of the oocytes at cortical granule stage and vitellogenesis stage, whereas they were compressed to cytoplasm margin in ovulated mature eggs and discharged into perivitelline space between cytoplasm membrane and egg envelope after egg fertilization. Further studies on distribution and translocation mechanism of the CaOC1q-like factor will be benefit to elucidate the unique function in oogenesis, oocyte maturation and egg fertilization.

Comparison between cytokine concentration in follicular fluid of poor and high responder patients and their influence of ICSI-outcome

OBJECTIVE

The aim of this study was to compare the cytokine concentration in follicular fluid (FF) of low and high responder intracytoplasmic sperm injection (ICSI) patients and to find out the impact of these cytokines in FF on ICSI outcome.

DESIGN

The levels of insulin-like growth factor (IGF)-I, IL-6, IL-8, epidermal growth factor (EGF), platelet-derived growth factor (PDGF), granulocyte-macrophage-colony stimulating factor (GM-CSF) were measured from low and high responder ICSI patients, the results were compared between the two groups and their influence on ICSI outcome was analysed.

MATERIAL AND METHODS

A total of 49 low (G.I) and 34 high (G.II) responder patients were enrolled in this study. FF was collected at the time of oocyte retrieval and measured either by enzyme-linked immunosorbent assay (IL-6, IL8, EGF, PDGF, GM-CSF) or radio immuno assay (IGF-I).

RESULTS

The concentration of IL-6 (pg/mL), IL-8 (pg/mL), IGF-I (ng/mL), PDGF (pg/mL), EGF (pg/mL), GM-CSF (pg/mL) in G.I was 6.0 +/- 4.3, 288.1 +/- 139.2, 0.416 +/- 0.089, 249.8 +/- 150.1, 9.12 +/- 5.5 and 1.45 +/- 2.10 and the corresponding value in G.II was 7.4 +/- 4.8, 208.6 +/- 64.0, 0.431 +/- 0.094, 387.6 +/- 36.0, 8.9 +/- 5.4 and 1.8 +/- 3.3, respectively. Only the PDGF concentration showed a significant (P = 0.007) difference between the two groups. Besides, negative correlations were found between PDGF and fertilization rate (r = -0.287; P = 0.046) of G.I. The mean number of retrieved (6.4 +/- 2.3 versus. 15.7 +/- 5.4) and fertilized (3.6 +/- 1.6 versus 7.0 +/- 4.5) oocytes differ significantly (P = 0.001) between the two groups. The fertilization rate was significantly higher in G.I than in G.II (60.9 +/- 25.1 versus 43.4 +/- 20.7%).

CONCLUSION

There was no significant difference between IGF-I, IL-6, IL-8, EGF and GM-CSF concentrations of low and high responder patients. Besides, PDGF was significantly (P = 0.007) higher in high responder compared with low responder patients. Moreover, in poor responder patients, a negative correlation was found between PDGF and fertilization rate. However, the cytokine levels in FF of the patients undergoing controlled ovarian hyperstimulation for ICSI could not be used as a marker of oocyte fertilization and implantation potential.

Relationships between concentrations of tumor necrosis factor-alpha and nitric oxide in follicular fluid and oocyte quality

PURPOSE

Our objective was to explain a relationship between concentrations of tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) in follicular fluid, oocyte quality, and outcomes of in vitro fertilization--embryo transfer (IVF-ET).

METHODS

The concentrations of TNF-alpha and NO were measured in 115 follicular fluid samples collected from 43 patients undergoing IVF-ET program, due to tubal obstruction, some with endometriosis (8 patients) or hydrosalpinx (5 patients). A correlation of these factors concentrations and the oocyte quality, the oocyte maturity, and infertility-associated diseases was analyzed.

RESULTS

No correlation was found between concentrations of NO and TNF-alpha in follicular fluid. NO concentrations in follicular fluids were significantly higher in patients with endometriosis (P < 0.001) or hydrosalpinx (P < 0.01) compared to the patients with just tubal obstruction. Follicular NO concentration differences according to oocyte maturity and oocyte quality were not found. In contrast, TNF-alpha concentrations in follicular fluids were significantly higher in poor quality oocytes (P < 0.05) but were not associated with infertility-associated diseases, such as hydrosalphinx or endometriosis,and the oocyte maturity. No significant differences in follicular levels of NO and TNF-alpha as well as IVF-ET parameters of pregnant and nonpregnant groups were revealed.

CONCLUSIONS

There is no significant correlation between the concentrations of NO and TNF-alpha in follicular fluid. NO levels in follicular fluid are altered in infertility-associated diseases. However, TNF-alpha levels but not NO levels influence oocyte quality. These results suggest that the production of NO and TNF-alpha in follicular fluid may be regulated via different pathways and can be tempered with infertility-associated diseases, thereby influencing oocyte quality locally.