Follicular proinflammatory cytokines and chemokines as markers of IVF success

Maternal obesity is associated with ovarian inflammation and upregulation of early growth response factor 1

Obesity impairs reproductive functions through multiple mechanisms, possibly through disruption of ovarian function. We hypothesized that increased adiposity will lead to a proinflammatory gene signature and upregulation of Egr-1 protein in ovaries from obese (OB; n = 7) compared with lean (LN; n = 10) female Sprague-Dawley rats during the peri-implantation period at 4.5 days postcoitus (dpc). Obesity was induced by overfeeding (40% excess calories for 28 days) via total enteral nutrition prior to mating. OB dams had higher body weight (P < 0.001), greater fat mass (P < 0.001), and reduced lean mass (P < 0.05) and developed metabolic dysfunction with elevated serum lipids, insulin, leptin, and CCL2 (P < 0.05) compared with LN dams. Microarray analyses identified 284 differentially expressed genes between ovaries from LN vs. OB dams (±1.3 fold, P < 0.05). RT-qPCR confirmed a decrease in expression of glucose transporters GLUT4 and GLUT9 and elevation of proinflammatory genes, including CCL2, CXCL10, CXCL11, CCR2, CXCR1, and TNFα in ovaries from OB compared with LN (P < 0.05). Protein levels of PI3K and phosphorylated Akt were significantly decreased (P < 0.05), whereas nuclear levels of Egr-1 (P < 0.05) were increased in OB compared with LN ovaries. Moreover, Egr-1 was localized to granulosa cells, with the highest expression in cumulus cells of preovulatory follicles. mRNA expression of VCAN, AURKB, and PLAT (P < 0.05) correlated with %visceral fat weight (r = 0.51, -0.77, and -0.57, respectively, P ≤ 0.05), suggesting alterations in ovarian function with obesity. In summary, maternal obesity led to an upregulation of inflammatory genes and Egr-1 expression in peri-implantation ovarian tissue and a concurrent downregulation of GLUTs and Akt and PI3K protein levels.

In Vitro Fertilization, Levels of Pro-Inflammatory Factors and Lipid Peroxidation

BACKGROUND

Infertility is a problem concerning 10-15% of the individuals in the fertile period. This study investigated effects of proinflammatory factors as well as lipid hydroperoxides (LPO) levels upon in vitro fertilization (IVF) success.

MATERIALS AND METHODS

In this prospective, non-randomized, controlled clinical study, sera obtained from 26 fertile (group-1), 26 infertile women before (group-2) and after (group-3) IVF treatment were analyzed. Leptin, leptin receptor, resistin, tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) were analyzed using enzyme-linked immunosorbent assay (ELISA). LPO was determined spectrophotometrically. Mann- Whitney U test, paired samples t test, Wilcoxon signed-rank test as well as Pearson correlation analysis by SPSS were performed for statistical analysis.

RESULTS

TNF-α, resistin and LPO levels increased (P=0.020, P=0.003, P=0.001, respectively) in group-3 compared to group-2. A significant increase in LPO was noted both in group-2 and -3 compared to controls (P=0.000). LPO were higher in non-pregnants than pregnants in group-2. For pregnants, significant correlations were observed between leptin and resistin in group-2 and TNF-α and leptin in group-3. None of these correlations were found for the women, who could not conceive.

CONCLUSION

LPO, leptin-resistin correlation, associations with TNF-α may be helpful during the interpretation of IVF success rates.

The effect of serum and follicular fluid amyloid-associated protein levels on in vitro fertilization outcome in patients with polycystic ovary syndrome

PURPOSE

In this study, we aimed to investigate serum and follicular fluid amyloid A protein levels in non-obese non-hyperandrogenic patients with polycystic ovary syndrome (PCOS) undergoing in vitro fertilization (IVF) and IVF outcome.

METHODS

A total of 81 patients undergoing IVF treatment, 41 patients diagnosed as PCOS according to the Rotterdam criteria (group I) and 40 patients with the etiology of male factor infertility (group II), were included in the study. On the day of oocyte pickup, serum and follicular fluid samples were collected from all patients.

RESULTS

Serum E2 level on the day of hCG (2849.93 ± 541.54 vs. 2494.28 ± 712.98) and total number of retrieved oocytes (13.73 ± 3.57 vs. 10.53 ± 4.07) were significantly higher in group I when compared to group II (p < 0.05). However, number of mature oocytes, fertilization rate, and clinical pregnancy rate did not differ (p > 0.05). No significant difference was found between two groups regarding the serum and follicular fluid amyloid A protein levels on the day of oocyte retrieval (p > 0.05).

Performance evaluation of FlowCytomix assays to quantify cytokines in patients with rheumatoid arthritis

OBJECTIVES

To compare the cytokine profile in RA patients and healthy control by using two methods-FlowCytomix assay and traditional ELISA.

METHODS

Cytokine levels were evaluated by FlowCytomix assay and ELISA in serum and supernatants of peripheral blood mononuclear cells (PBMC) cultures with and without stimulation by phytohaemagglutinin (PHA).

RESULTS

The levels of IL-6, IL-1β, and TNF-α were significantly higher in sera of RA patients than those of healthy controls. The levels of IL-22, IL-6, IL-1β, TNF-α, and IL-10 were higher in unstimulated PBMC culture supernatant of RA patients than those of healthy controls. PHA stimulation significantly increased the production of proinflammatory cytokines from PBMC with RA patients. Compared with detectable cytokine levels in sera, cytokine concentration in the supernatant of PBMCs was remarkably higher. FlowCytomix and ELISA showed significant correlation in detecting cytokines. However, the FlowCytomix assay detected more cytokines than ELISA.

CONCLUSION

The supernatant of PBMCs provide a fine condition for the study of cytokine production because of the lack of interference factors in sera. The FlowCytomix assay is more sensitive than ELISA in detecting cytokines from RA patients. Multiple cytokine signatures using FlowCytomix assay may represent a more realistic approach in the future of personalized medicine in RA.

TNF-α Suppressed FSH-Induced LH Receptor Expression Through Transcriptional Regulation in Rat Granulosa Cells

Several inflammatory cytokines regulate ovarian function. TNF-α is produced in granulosa cells under physiological conditions and has a reciprocal action on follicle development. In contrast, in pelvic inflammatory diseases, TNF-α is excessively produced in the pelvic cavity and has an adverse effect on reproductive functions. The objective of this study was to elucidate the mechanism of action of TNF-α on the expression of LH receptor (LHR) in immature rat granulosa cells. TNF-α suppressed FSH-induced LHR mRNA and protein expression and was not associated with cAMP accumulation. By using a luciferase assay, the construct containing base pairs -1389 to -1 of the rat Lhcgr promoter revealed that TNF-α decreased FSH-induced promoter activity. In response to TNF-α, nuclear factor (NF)-κB p65 was translocated to the nucleus, and the suppressive effect of TNF-α on LHR mRNA expression was abrogated by an NF-κB inhibitor. In a chromatin immunoprecipitation assay, TNF-α induced the association of NF-κB p65 with the rat Lhcgr transcriptional promoter region. NF-κB p65 and histone deacetylase (HDAC) interact to mediate expression of several genes at a transcriptional level. HDAC activity is thought to induce tight connections within local chromatin structures and repress gene transcription. Furthermore, the TNF-α-induced suppression of LHR mRNA expression was blocked by an HDAC inhibitor. Taken together, these results suggest that the interaction of NF-κB p65 with HDAC in the promoter region of rat Lhcgr might be responsible for TNF-α action on the regulation of LHR.

Inflammation and Human Ovarian Follicular Dynamics

Inflammation is a biologic process that mediates tissue effects including vasodilation, hyperemia, edema, collagenolysis, and cell proliferation through complex immunologic pathways. In regard to the ovary, inflammation has key physiologic roles in ovarian folliculogenesis and ovulation. On the other hand, inflammatory processes are subject to underlying pathology and, if pushed, proinflammatory conditions may have a negative impact on ovarian follicular dynamics. Obesity and polycystic ovary syndrome (PCOS) serve as examples of conditions associated with chronic endogenous production of low-grade proinflammatory cytokines. Both conditions negatively impact ovarian folliculogenesis and ovulation. The pages that follow summarize the role of inflammation in normal ovarian follicular dynamics and evidence for its role in mediating the negative effects of obesity and PCOS on ovarian follicular dynamics. The review concludes with a summary supporting a role for lifestyle factors that favorably impact inflammatory process involved in obesity and PCOS to improve ovarian function.

Oocyte environment: follicular fluid and cumulus cells are critical for oocyte health

Bidirectional somatic cell-oocyte signaling is essential to create a changing intrafollicular microenvironment that controls primordial follicle growth into a cohort of growing follicles, from which one antral follicle is selected to ovulate a healthy oocyte. Such intercellular communications allow the oocyte to determine its own fate by influencing the intrafollicular microenvironment, which in turn provides the necessary cellular functions for oocyte developmental competence, which is defined as the ability of the oocyte to complete meiosis and undergo fertilization, embryogenesis, and term development. These coordinated somatic cell-oocyte interactions attempt to balance cellular metabolism with energy requirements during folliculogenesis, including changing energy utilization during meiotic resumption. If these cellular mechanisms are perturbed by metabolic disease and/or maternal aging, molecular damage of the oocyte can alter macromolecules, induce mitochondrial mutations, and reduce adenosine triphosphate production, all of which can harm the oocyte. Recent technologies are now exploring transcriptional, translational, and post-translational events within the human follicle with the goal of identifying biomarkers that reliably predict oocyte quality in the clinical setting.

Impact of exogenous gonadotropin stimulation on circulatory and follicular fluid cytokine profiles

Background. The natural cycle is the prototype to which we aspire to emulate in assisted reproduction techniques. Increasing evidence is emerging that controlled ovarian hyperstimulation (COH) with exogenous gonadotropins may be detrimental to oogenesis, embryo quality, and endometrial receptivity. This research aimed at assessing the impact of COH on the intrafollicular milieu by comparing follicular fluid (FF) cytokine profiles during stimulated in vitro fertilization (IVF) and modified natural cycle (MNC) IVF. Methods. Ten women undergoing COH IVF and 10 matched women undergoing MNC IVF were recruited for this pilot study. 40 FF cytokine concentrations from individual follicles and plasma were measured by fluid-phase multiplex immunoassay. Demographic/cycle/cytokine data were compared and correlations between cytokines were computed. Results. No significant differences were found between COH and MNC groups for patient and cycle demographics, including outcome. Overall mean FF cytokine levels were higher in the MNC group for 29/40 cytokines, significantly so for leukaemia inhibitory factor and stromal cell-derived factor-1α. Furthermore, FF MNC cytokine correlations were significantly stronger than for COH data. Conclusions. These findings suggest that COH perturbs intrafollicular cytokine networks, in terms of both cytokine levels and their interrelationships. This may impact oocyte maturation/fertilization and embryo developmental competence.

Serum tumor necrosis factor-α, interleukin-6, monocyte chemotactic protein-1 and paraoxonase-1 profiles in women with endometriosis, PCOS, or unexplained infertility

OBJECTIVE

To investigate the serum levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), monocyte chemotactic protein-1 (MCP-1), and Paraoxonase-1 (PON-1) during fertility treatment of women with endometriosis (Endo), PCOS or unexplained infertility (Unexpl).

METHODS

Thirty-six patients with Endo, PCOS or Unexpl undergoing controlled ovarian stimulation for IVF or IUI were consented and their serum, on day-3 (baseline) and at the end of FSH treatment (peak), was collected and investigated for levels of TNF-α, IL-6, MCP-1, and PON-1. Correlations, ANOVA and Student's t-test were used for statistical analysis.

RESULTS

Peak serum levels of IL-6, MCP-1 and PON-1 were positively correlated to E2 peak levels. TNF-α levels were inversely correlated to estradiol levels and they were lower in patients who ultimately became pregnant when compared to non-pregnant (P < 0.05). Mean TNF-α levels were significantly higher in Unexpl group (P < 0.05). The mean levels of IL-6, and MCP-1 were significantly (p < 0.05) higher in women with PCOS compared with Endo and Unexpl. No differences were found between the three clinical groups in patient's age, BMI, Day-3 FSH, PON-1 and pregnancy outcome.

CONCLUSION

Circulating cytokine levels were influenced by ovarian stimulation, as demonstrated by increased levels of IL-6, MCP-1 and PON-1, and decreased level of TNF-α at the end of controlled ovarian stimulation. While evidence of relationship between circulating cytokines with mild endometriosis was not found, PCOS was associated with elevated serum IL-6 and MCP-1 but lower TNF-α concentration. Unexplained infertility was associated with elevated TNF-α level. No relationship between serum PON-1 concentration and PCOS, mild endometriosis or unexplained infertility was noted.

The gene expression profile of cumulus cells reveals altered pathways in patients with endometriosis

PURPOSE

The objective of this experimental study was to compare the global gene expression profile of CC of mature oocytes in 18 patients with severe endometriosis and CC in 18 control patients affected by a severe male factor.

METHODS

For each group, the CC were pooled, RNA was extracted and a microarray performed. For validating the microarray, a quantitative real-time PCR was performed in the CC of an independent set of patients with endometriosis (n = 5) and controls (n = 7).

RESULTS

595 differentially expressed genes (320 down-regulated, 275 up-regulated, p < 0.05, fold change ≥1.5) were identified. The most significant changes were observed in genes involved in the chemokine signaling and cell-cell or cell-extracellular matrix adhesion pathways. Several genes of these pathways were down-regulated in endometriosis. Individual RT-PCR assays confirmed the microarray for ten genes.

CONCLUSIONS

Several genes involved in the chemokine mediated-signaling pathway and in the functional cross-talk between CC and the oocyte are down-regulated in endometriosis CC. The impairment of these processes could explain the reduction of oocyte competence in endometriosis. This preliminary knowledge could be the starting point for a more detailed elucidation of the relationship between endometriosis and oocyte competence.

Management of reproduction and pregnancy complications in maternal obesity: which role for dietary polyphenols?

Obesity is a global and dramatic public health problem; maternal obesity represents one of the main risk factors of infertility and pregnancy complications as it is associated with adverse maternal and offspring outcomes. In the last few years, adipose tissue dysfunction associated with altered adipocytokine secretion has been suggested to play a critical role in all the phases of reproductive process. Obesity is a nutrition-related disorder. In this regard, dietary intervention strategies, such as high intake of fruit and vegetables, have shown significant effects in both preserving health and counteracting obesity-associated diseases. Evidence has been provided that polyphenols, important constituents of plant-derived food, can influence developmental program of oocyte and embryo, as well as pregnancy progression by modulating several cellular pathways. This review will examine the controversial results so far obtained on adipocytokine involvement in fertility impairment and pregnancy complications. Furthermore, the different effects exerted by polyphenols on oocyte, embryo, and pregnancy development will be also taken in account.

An integrated approach based on multiplexed protein array and iTRAQ labeling for in-depth identification of pathways associated to IVF outcome

The emergence of high-throughput protein quantification methodologies has enabled the comprehensive characterization by longitudinal and cross-sectional studies of biological fluids under physiological and pathological conditions. In particular, the simultaneous investigation of cytokines and growth factors signaling pathways and their associated downstream effectors by integrated multiplexed approaches offers a powerful strategy to gain insights into biological networks and processes in living systems. A growing body of research indicates that bioactive molecules of human reproductive fluids, including human follicular fluid (hFF), may affect oocyte quality, fertilization and embryo development, thus potentially influencing the physiopathology of pregnancy-related conditions.

In this work, an iTRAQ labeling strategy has been complemented with a multiplexed protein array approach to analyze hFFs with the aim to investigate biological processes and pathways related to in vitro fertilization (IVF) outcome. The iTRAQ labeling strategy lead to the quantification of 89 proteins, 30 of which were differentially expressed in hFFs with successful compared to unsuccessful IVF outcome. The targeted study, based on multiplexed antibody protein arrays, allowed the simultaneous quantification of 27 low abundance proteins, including growth factors, chemokines and cytokines endowed with pro- and anti-inflammatory activity. A significant number of differentially regulated proteins were involved in biological functions related to blood coagulation, acute phase response signaling and complement system. Overall, the present results provide an integrated overview of protein changes in hFFs associated to IVF outcome, thus improving current knowledge in reproductive medicine and fertility research.

Detection of soluble ST2 in human follicular fluid and luteinized granulosa cells

Follicular fluid (FF) contains various cytokines that are involved with folliculogenesis, some of which have been shown to be associated with oocyte quality and the implantation potential of a resulting embryo. Several IL-1 family members have previously been identified in FF. This study investigates a newly identified member of the family, IL-33, and its receptor ST2, comparing values to those of FF Granulocyte-Colony Stimulating Factor (G-CSF) – a known predictor of Assisted Reproductive Technology (ART) success. FF was collected from patients undergoing in vitro fertilisation/intra-cytoplasmic sperm injection (IVF/ICSI) at oocyte retrieval to analyse IL-33 and sST2 expression in human follicles. sST2, but not IL-33, is highly increased in the FF compared to plasma levels (up to 7.9-fold), with higher levels in larger follicles (p<0.05). Furthermore, we identify that human luteinised granulosa cells are one possible source of the FF sST2, as these cells express and secrete sST2 when cultured ex vivo. FF associated with oocytes which when fertilised develop into good quality embryos have higher sST2 levels than those which are graded average (p<0.01). These embryos were transferred to the patient and levels of FF sST2 compared between successful and unsuccessful ICSI cycles. However unlike G-CSF, sST2 levels cannot be used to predict cycle outcome.

Chemokines in the pathogenesis of endometriosis and infertility

Endometriosis is a chronic benign disease that affects women of reproductive age causing abdominal pain and infertility. Its pathogenesis remains obscure despite all the research conducted over the past 100 years. However, there is a consensus among the specialists that the basis of its pathophysiology would be multifactorial. Many publications have demonstrated that chemokines are somehow associated with the development of endometriosis and infertility. In this study, we reviewed all PubMed literature using MeSH terms "chemokines" and "endometriosis" as well as "chemokines" and "female infertility" to establish what we know and what we do not yet know about this relationship.

Do endometriomas induce an inflammatory reaction in nearby follicles?

STUDY QUESTION

Do endometriomas induce an inflammatory reaction with increased cytokine concentrations in nearby follicles and thereby affect follicular development during controlled ovarian stimulation for in vitro fertilization (IVF)?

SUMMARY ANSWER

With most endometriomas, there is no evidence of increased cytokine concentrations in the ipsilateral leading follicle. Infrequently, the concentration of inflammatory cytokines is increased in the follicular fluid (FF) and associated with diminished ovarian response.

WHAT IS KNOWN ALREADY

The link between peritoneal endometriosis, inflammation and infertility is well established; however, the association between intraovarian inflammation and endometrioma is unknown.

STUDY DESIGN, SIZE, DURATION

This prospective cohort study included 117 infertile women undergoing IVF in a tertiary infertility clinic at Oslo University Hospital Rikshospitalet, Norway, during the period May 2009 to September 2011.

PARTICIPANTS, SETTING, METHODS

There were 47 patients with unilateral endometrioma and 17 patients with bilateral endometrioma, while the 53 control patients had unexplained or male factor infertility. Concentrations of IL-1β, IL-6, IL-8, IL-10, IL-12 and TNF-α were measured in serum and in the fluid of the largest pre-ovulatory follicles from each ovary of each participant.

MAIN RESULTS AND THE ROLE OF CHANCE

Cytokine levels in the follicular fluid from the two ovaries in women with unilateral endometriomas were comparable, and were not significantly altered compared with that of control groups with male factor infertility, unexplained infertility or bilateral endometriomas. Compared with serum levels, the follicular fluid levels of IL-8 and IL-6 were higher, suggesting a local production or recruitment. The follicular fluid IL-8 level varied considerably and showed an inverse relationship with IL-12, IL-10 and TNF-∝, suggesting a complex interaction between various immune cells. A small group of patients (n = 3) had increased levels of all follicular fluid cytokines combined with moderately to slightly elevated serum levels and these patients had a significantly lower ovarian response.

LIMITATIONS, REASONS FOR CAUTION

For ethical reasons, the endometriomas were diagnosed indirectly by ultrasound rather than by histology.

WIDER IMPLICATIONS OF THE FINDINGS

This paper reveals that endometriomas seldom induce inflammation in nearby follicles during IVF; therefore, routine cystectomy prior to IVF may not be necessary. Cytokine levels in the follicular fluid, nonetheless, show distinctive patterns and increased levels may be linked to reduced ovarian response independent of the cause of infertility.