Interleukin 15 concentrations in follicular fluid and their effect on oocyte maturation in subfertile women undergoing intracytoplasmic sperm injection

The significant role of IL-15, IL-22, IL-37, and caspase 9 in polycystic ovary syndrome: A case-control study in a sample of Iraqi women

The study aims to evaluate the significant role of interleukin 15 (IL-15), IL-22, IL-37, and Caspase 9 gene expression in polycystic ovary syndrome (PCOS), focusing on the underlying mechanisms and potential diagnostic or therapeutic implications. Peripheral blood has been collected, and serum was separated for the evaluation of the serum IL-15, IL-22, and IL-37. The ELISA technique has been carried out to determine the serum levels of understudied factors mentioned above in Iraqi women patients diagnosed with PCOS (No. = 90) via a specialized gynecologist and healthy fertile women (No. = 48) as a control group. In addition, a genetic study on the expression of the caspase 9 gene in these patients had been performed. The data reveals statistically significant differences in interleukin levels in PCOS patients versus the control group. Specifically, the PCOS group exhibits significantly higher levels of IL-15 and IL-22 as compared to the control group. Conversely, the PCOS group shows significantly lower levels of IL-37 compared to the control group. The results showed no statistically significant difference in the mean expression of the Caspase 9 gene when comparing these fold graduations. However, it's worth noting that a higher fold frequency was observed in both the PCOS and control groups, with 57.1 % and 60 %, respectively, having folds less than 1. The distribution of folds varied across other categories was also addressed. Additionally, there was a notable difference in the frequency of 11.4 % in the PCOS group compared to 2 % in the control group for folds greater than 9. The findings suggest that interleukins, particularly IL-22 and IL-37, hold promise as diagnostic markers for distinguishing PCOS from healthy conditions. However, the potential diagnostic utility of the Caspase 9 gene expression was not confirmed in this study.

Associations of the levels of adipokines and cytokines in individual follicles with in vitro fertilization outcomes in women with different ovarian reserves

BACKGROUND

To a large extent, the ovarian reserve determines a woman's reproductive potential. The etiological and pathological mechanisms of diminished ovarian reserve (DOR) remain unclear, and no reliable treatment is currently available for DOR. Adipokines and cytokines in follicular fluid (FF) play pivotal roles in follicular development and maturation. The concentrations of adipokines and cytokines in FF from individual follicles of women with DOR undergoing in vitro fertilization (IVF) were studied. In particular, we investigated the associations between the levels of adipokines and cytokines in individual FFs from women with different ovarian reserves and between the follicular levels of adipokines and cytokines and IVF outcomes in individual follicles.

METHODS

A total of 115 women who underwent IVF were recruited. Patients diagnosed with DOR, defined as a basal antral follicle count < 5 or an anti-Mullerian hormone concentration < 1.1 ng/mL, were assigned to the DOR group, while patients with a normal ovarian reserve (NOR) were assigned to the NOR group. FF was sampled from the first follicle with a diameter of approximately 18-20 mm from each patient, and the IVF outcome of the oocyte from the corresponding follicle was tracked. The levels of 5 adipokines (including visfatin-1, monocyte chemoattractant protein-1 [MCP-1], resistin, leptin, and chemerin) and 3 cytokines (including interleukin [IL]-6, IL-12p70, and tumor necrosis factor [TNF]-α) in FF were determined by Luminex technology.

RESULTS

The follicular levels of TNF-α, IL-6, visafatin, MCP-1, IL-12, and chemerin were significantly lower in women with NOR than in those with DOR. The follicular level of IL-6 was negatively correlated with the quality of embryos according to the binary logistic regression analysis, while the follicular levels of adipokines and other cytokines did not correlate with IVF outcomes regardless of the woman's ovarian reserve.

CONCLUSIONS

Our study demonstrated that the levels of adipokines and cytokines in individual follicles in women with DOR were different from those in women with NOR, indicating that increased intrafollicular inflammation might be related to DOR. Moreover, a high follicular level of IL-6 might negatively impact embryo quality.

A Case-Control Study of Follicular Fluid Cytokine Profiles in Women with Diminished Ovarian Reserve

Ovarian reserve is an important determinant of a woman's reproductive potential, and women with diminished ovarian reserve (DOR) often seek in vitro fertilization (IVF). The underlying etiology of DOR is unknown, but follicular fluid cytokine concentrations likely play a role in follicular development and maturation. The present study seeks to investigate the expression of cytokines in follicular fluid (FF) of women with DOR undergoing IVF and explore correlated functional pathways. One hundred ninety-four women undergoing ovarian stimulation were recruited at the time of oocyte retrieval. Women were classified as having DOR if they met one or more of the following criteria: AMH < 1 ng/ml, FSH > 10 mIU/ml, and/or AFC < 10. Controls included women undergoing IVF for male factor, tubal factor due to tubal ligation, or planned oocyte cryopreservation (non-oncologic). The concentrations of 480 cytokines and related growth factors in follicular fluid were determined using a multiplex immunoassay. Fifty-nine cytokines had significantly different concentrations (53 higher and 6 lower) in the DOR relative to the control group after adjusting for age and body mass index (BMI) (false discovery rate; FDR < 0.1). Using the most informative 44 biomarkers as indicated by a random forest (RF) model, an area under the curve (AUC) of 0.78 was obtained. Thus, follicular microenvironment differs between women with DOR and normal ovarian reserve. The differentially expressed cytokines belong to diverse processes that are primarily involved in follicular maturation and ovulation. These changes may play an important role in treatment outcomes in women with DOR.

Evaluation of expression CXCL8 chemokine and its relationship with oocyte maturation and embryo quality in the intracytoplasmic sperm injection method

BACKGROUND

The present study aimed to evaluate the expression of the chemokine CXCL8 in both mRNA and protein levels in the serum, follicular fluid (FF), and cumulus cells (CCs) and its relationship with oocyte maturation and embryo quality in women undergoing intracytoplasmic sperm injection (ICSI).

METHODS

A total of 87 women who underwent an ICSI cycle were evaluated in two groups, including the case group (female factor infertility) and the control group (fertile). In the serum, FF, and CCs, the protein and mRNA expression of CXCL8 were measured using immunosorbent assay and Real-Time PCR, respectively. The quality and quantity of the oocytes and embryos were assessed, and the relationship of protein and mRNA CXCL8 was evaluated with oocyte maturation and embryo quality.

RESULTS

The level of protein and mRNA of CXCL8 was significantly higher in the serum, FF, and CCs in the case group than in the control group. In the case group, the expression of mRNA and protein of CXCL8 had a significant increase in FF and CCs compared to serum; also, there was a CXCL8 protein significant increase in FF compared to CCs. The count of oocytes obtained, MII oocytes and the percentage of oocyte maturity significantly decreased in the case group. The expression of CXCL8 was inversely related to oocyte maturation, but no relationship was observed with embryo quality.

CONCLUSIONS

The elevated concentrations of CXCL8 in the serum and FF seem to be a predictor as a potential non-invasive biomarker for the oocyte maturation outcome in women with different causes of female factor infertility.

IL-15 Participates in the Pathogenesis of Polycystic Ovary Syndrome by Affecting the Activity of Granulosa Cells

BACKGROUND

Low-grade chronic inflammation may contribute to the pathogenesis of polycystic ovary syndrome (PCOS). Interleukin-15 (IL-15) is a proinflammatory cytokine involved in the development of chronic inflammation leading to obesity-associated metabolic syndrome. However, the concentration of IL-15 in follicular fluid of patients with PCOS has yet been evaluated.

OBJECTIVES

The aim of this study is to evaluate the expression level of IL-15 in both patients with PCOS and PCOS mice model and investigate the functional effect of IL-15 on ovarian granulosa cells.

METHODS

The level of IL-15 in follicular fluid (FF) was measured using cytokine array and enzyme linked immunosorbent assay (ELISA) in two cohorts from 23 PCOS patients and 18 normo-ovulatory controls. PCOS mice model was induced by subcutaneously implanted with letrozole pellet for 21 days. The expression level of IL-15 in serum, ovarian, and subcutaneous adipose tissue in PCOS mice model was measured by ELISA, real-time polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), and immunofluorescence. The effect of IL-15 on the proliferation and apoptosis of the KGN cells and mouse ovarian granulosa cells (GCs) were detected by CCK-8 assay and flow cytometry, respectively. Transcript expression of 17α-hydroxylase17,20-lyase (CYP17A1), cytochrome P450 family 19 subfamily A member 1(CYP19A1), FSH receptor (FSHR), steroidogenic acute regulatory protein (StAR), and proinflammatory cytokine were quantified using RT-PCR. The protein level and phosphorylation level of p38 MAPK and JNK are detected by Western blot. Concentration of dehydroepiandrosterone sulfate (DHEAS) and progesterone (P)were measured by ELISA.

RESULTS

IL-15 expression in follicular fluid of patients with PCOS was significantly elevated compared with the control group, and similar results were observed in the ovarian and subcutaneous adipose tissue of PCOS mice models. Furthermore, the elevated FF IL-15 levels have a positive correlation with the serum testosterone levels. FSHR co-localized with IL-15 indicating that IL-15 production originate from ovarian granulose cells. IL-15 treatment inhibited proliferation and promoted apoptosis of KGN cells and mouse GCs. Moreover, IL-15 upregulated the transcription levels of CYP17A1, IL-1b and Ifng KGN cells. Similar results were observed in mouse GCs except concentration of DHEAS was higher in IL-15 treatment. IL-15 promoted p38 MAPK and JNK phosphorylation in KGN cells, treating KGN cells with p38 MAPK inhibitor SP600125 and JNK inhibitor SB203580 could reverse the effect of IL-15 on the proliferation and function of KGN cells.

CONCLUSION

The results indicate that IL-15 is involved in the pathogenesis of PCOS potentially by affecting survival, the inflammation state and steroidogenesis of granulosa cells. The practical significance of this association between IL-15 and the pathogenesis of PCOS needs further investigation.

Intraovarian injection of platelet-rich plasma in assisted reproduction: too much too soon?

The prospect of ovarian rejuvenation offers the tantalising prospect of treating age-related declines in fertility or in pathological conditions such as premature ovarian failure. The concept of ovarian rejuvenation was invigorated by the indication of the existence of oogonial stem cells (OSCs), which have been shown experimentally to have the ability to differentiate into functional follicles and generate oocytes; however, their clinical potential remains unknown. Furthermore, there is now growing interest in performing ovarian rejuvenation in situ. One proposed approach involves injecting the ovary with platelet rich plasma (PRP).

PRP is a component of blood that remains after the in vitro removal of red and white blood cells. It contains blood platelets, tiny anucleate cells of the blood, which are responsible for forming athrombus to prevent bleeding. In addition, PRP contains an array of cytokines and growth factors, as well as a number of small molecules.The utility ofPRP has been investigatedin a range of regenerative medicine approaches and has been shown to induce differentiation of a range of cell types, presumably through the action of cytokines.

A handful ofcasereports have described the use of PRP injections into the ovaryin the human, and while these clinical data report promising results, knowledge on the mechanisms and safety of PRP injections into the ovary remain limited.In this article, we summarise some of the physiological detail of platelets and PRP, before reviewing the existing emerging literature in this area. We then propose potential mechanisms by which PRP may be eliciting any effects before reflecting on some considerations for future studies in the area. Importantly, on the basis of our existing knowledge, we suggest that immediate use of PRP in clinical applications is perhaps premature and further fundamental and clinical research on the nature of ovarian insufficiency, as well as the mechanism by which PRP may act on the ovary, is needed to fully understand this promising development.

Upregulation of IL-15 in the placenta alters trophoblasts behavior contributing to gestational diabetes mellitus

Background

Interleukin-15 (IL-15), a member of the ‘four α-helix bundle’ cytokine family, has been associated with many inflammatory and metabolic diseases. Abnormal expression of IL-15 has been linked to the occurrence and development of obesity and diabetes. However, there is a paucity of research on the involvement of IL-15 in Gestational Diabetes Mellitus (GDM). This study aims at investigating the role of IL-15 in the pathogenesis of GDM.

Results

IL-15 was consistently expressed in the placenta throughout pregnancy and dynamically changed with pregnancy progress. Trophoblasts have been identified as the major source of IL-15 in the placenta. Expression of IL-15 was significantly increased in the placenta of GDM and in the trophoblasts cultured with high glucose (HG). In our study, expression of IL-15 in the placenta was positively correlated with blood glucose concentration of 75 g Oral Glucose Tolerance Test (OGTT), and was inversely correlated with weight of newborns. Further investigations in vitro showed that exogenous addition of IL-15 promoted trophoblasts proliferation, improved invasion and tube formation ability by activating the JAK/STAT signaling pathway, which be blocked by JAK inhibitors.

Conclusion

Our results demonstrated that IL-15 expression in the placenta was dynamically changing during pregnancy, and it was upregulated in the placenta of GDM patients. Furthermore, IL-15 altered the biological behavior of trophoblasts through JAK/STAT signaling pathway in vitro, and may contributed to the placental pathology of GDM. Our findings provide a new direction for studying the pathophysiological changes of placenta in GDM.

Description of the Follicular Fluid Cytokine and Hormone Profiles in Human Physiological Natural Cycles

PURPOSE

Exogenous gonadotrophins administration during in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles could significantly alter the endogenous follicular regulation system and could influence oocyte quality. The analysis of the follicular fluid (FF) cytokine and hormone profiles in physiological natural cycles is crucial to appreciate the role of FF milieu on follicle development. So far, the FF cytokine profile has been analyzed only in controlled ovarian stimulation cycles and in modified natural cycles. Our study defines, in physiological natural cycles, the cytokine and hormone profiles of individual FF aspirated from antral follicles.

METHODS

A total of 203 FFs obtained from 83 women with regular menstrual cycles undergoing ovarian tissue cryopreservation were analyzed: 115 FFs from Group 1 (10 to 29 years of age) and 88 FFs from Group 2 (30 to 40 years of age). In individual FF, 27 cytokines were measured with xMAP technology, and progesterone, estrone, estradiol, testosterone, androstenedione concentrations were determined by liquid chromatography-tandem mass spectrometry.

RESULTS

FF hormone profiles were not different in follicular and luteal phase, suggesting that FF hormones are regulated independently of the endogenous gonadotrophins-possibly because 74% of the punctured follicles, which were ≤6 mm, did not require cyclic pituitary function. The follicle size was influenced not only by the FF cytokine profile but also by the FF hormone profile, both of which are dependent on age.

MAIN CONCLUSIONS

In physiological natural cycles, FF hormones seems to be regulated independently of the endogenous gonadotropins. Age influences FF hormone and cytokine profiles and the compelling relationship between FF hormones and FF cytokines could influence the follicle development.

STAT3 Is an Upstream Regulator of Granzyme G in the Maternal-To-Zygotic Transition of Mouse Embryos

The maternal-to-zygotic transition (MZT), which controls maternal signaling to synthesize zygotic gene products, promotes the preimplantation development of mouse zygotes to the two-cell stage. Our previous study reported that mouse granzyme g (Gzmg), a serine-type protease, is required for the MZT. In this study, we further identified the maternal factors that regulate the Gzmg promoter activity in the zygote to the two-cell stage of mouse embryos. A full-length Gzmg promoter from mouse genomic DNA, FL-pGzmg (−1696~+28 nt), was cloned, and four deletion constructs of this Gzmg promoter, Δ1-pGzmg (−1369~+28 nt), Δ2-pGzmg (−939~+28 nt), Δ3-pGzmg (−711~+28 nt) and Δ4-pGzmg (−417~+28 nt), were subsequently generated. Different-sized Gzmg promoters were used to perform promoter assays of mouse zygotes and two-cell stage embryos. The results showed that Δ4-pGzmg promoted the highest expression level of the enhanced green fluorescent protein (EGFP) reporter in the zygotes and two-cell embryos. The data suggested that time-specific transcription factors upregulated Gzmg by binding cis-elements in the −417~+28-nt Gzmg promoter region. According to the results of the promoter assay, the transcription factor binding sites were predicted and analyzed with the JASPAR database, and two transcription factors, signal transducer and activator of transcription 3 (STAT3) and GA-binding protein alpha (GABPα), were identified. Furthermore, STAT3 and GABPα are expressed and located in zygote pronuclei and two-cell nuclei were confirmed by immunofluorescence staining; however, only STAT3 was recruited to the mouse zygote pronuclei and two-cell nuclei injected with the Δ4-pGzmg reporter construct. These data indicated that STAT3 is a maternal transcription factor and may upregulate Gzmg to promote the MZT. Furthermore, treatment with a STAT3 inhibitor, S3I-201, caused mouse embryonic arrest at the zygote and two-cell stages. These results suggest that STAT3, a maternal protein, is a critical transcription factor and regulates Gzmg transcription activity in preimplantation mouse embryos. It plays an important role in the maternal-to-zygotic transition during early embryonic development.

Investigating apoptotic, inflammatory, and growth markers in poor responders undergoing natural in vitro fertilization cycles: a pilot study

This study investigates follicular fluid (FF) from patients with poor and normal ovarian response undergoing natural assisted reproductive technology cycles. We report about (1) cell-free DNA (cfDNA), which reflects apoptosis; (2) corticotropin-releasing hormone (CRH); (3) interleukin (IL)-15, which reflects inflammation; (4) granulocyte colony-stimulating factor (G-CSF); (5) vascular endothelial growth factor (VEGF); and (6) insulin-like growth factor I (IGF-I), which reflects follicular growth. Forty-four poor responders and 44 normal responders-according to the Bologna criteria-were recruited. FF samples were prepared for cfDNA quantification employing Q-PCR and for CRH, IL-15, G-CSF, VEGF, and IGF-I quantification employing ELISA. Statistically nonsignificant different levels of FF cfDNA, CRH, IL-15, VEGF, and IGF-I were observed. Interestingly, statistically significant higher G-CSF levels were observed in normal responders (302.48 ± 474.36 versus 200.10 ± 426.79 pg/mL, P = 0.003). Lower cfDNA integrity was observed in cycles resulting in clinical pregnancy for both groups (normal: 0.07 ± 0.04 versus 0.25 ± 0.17 ng/μL, P < 0.001; poor: 0.10 ± 0.06 versus 0.26 ± 0.12 ng/μL, P < 0.001). The results predominantly showcase similarities between normal and poor responders pertaining to inflammatory, apoptotic, and growth factors. This may be attributed to the employment of natural cycles in order to exclude controlled ovarian stimulation as a factor-indicating its detrimental effect. As G-CSF levels presented significantly higher in normal responders, its vital role in understanding a compromised ovarian response is highlighted.

Human follicular fluid shows diverse metabolic profiles at different follicle developmental stages

BACKGROUND

To investigate the metabolic profiles in the follicular fluid (FF) samples from patients undergoing in vitro fertilization (IVF) and to analyze the correlations with follicular development.

METHODS

The FF samples were obtained from participants (N = 26) who were receiving IVF under the gonadotropin-releasing hormone agonist (GnRH-a) long protocol stimulation and were collected separately from small (8-13 mm) and large (17-22 mm) follicles at the time of oocyte retrieval. Metabolomic analysis of the FF samples was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

RESULTS

The results demonstrated that the size of the follicle influences the metabolic signature of the FF according to the profile and differential metabolites. Dehydroepiandrosterone (DHEA), which is enriched in steroid hormone biosynthesis, correlated negatively with the oocyte maturation rate and the high-quality embryo rate, and thus could be used to estimate the predictive diagnostic potential of follicular development.

CONCLUSION

The FF has different metabolic characteristics in different stages of follicular development. Exploring meaningful metabolites could predict follicular development, and modifications of these metabolites could influence follicular development.

Interleukins' expression profile changes in granulosa cells of preovulatory follicles during the postpartum period in dairy cows

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Interleukin (IL) 4 expression was significantly altered during the postpartum period.

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IL8 and IL15 were the most significantly induced during the postpartum period.

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Correlation between increased BHB levels and induction of proinflammatory cytokines.

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Interleukins analyzed were differentially regulated during follicular development.

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ILs induced during the post-partum period were also induced 24 h post-hCG injection.

The postpartum period in dairy cows is associated with a state of temporary negative energy balance and could induce functional changes into ovarian granulosa cells (GC) resulting in significant impact on the ovarian function and fertility. Yet, the regulation of interleukin receptors (ILRs) in GC as well as ILs expression profile during the postpartum period have not been fully investigated. We hypothesized that the postpartum period is associated with changes in ILs expression profile that could affect follicular development and ovulation rate. First, we aimed to investigate the expression and regulation of different IL and IL receptors in GC at different stages of follicular development and then analyse the changes in target ILs expression profile induced during the postpartum period. In the first objective, normal cycling cows were selected and GC were collected from small follicles (SF), dominant follicles at day 5 of the estrous cycle (DF), and ovulatory follicles, 24 h following hCG injection (OF). In the second objective, dairy cows between 50 and 70 days postpartum were randomly selected, and β-hydroxybutyrate (BHB) concentrations were measured in blood samples in order to assign cows to the BHB⁺ group (>1.4 mmol/L) or BHB⁻ group (<1.2 mmol/L). GC were collected from preovulatory follicles by transvaginal aspiration. Total RNA was extracted from GC of all groups for analysis of target ILs and ILRs expression. Steady-state mRNA levels of IL4R was strongest in the DF, while IL15R expression was greatest in the OF, and IL21R showed increased steady-state mRNA levels in the corpus luteum as compared to the different groups of follicles. Overall, expression of IL1A, IL1B, IL8, IL15, IL23 and TNFα was stronger in OF as compared to DF, while IL4 and IL10 expression was stronger in SF than in DF. Similarly, expression of IL1A, IL1B, IL8, IL15, IL23, and TNFα were significantly stronger in GC of BHB⁺ cows than in the control, while IL4 expression was significantly reduced in BHB⁺ as compared to control cows. We have established an IL expression profile, which suggest a correlation with BHB levels during the postpartum period. Additionally, we have demonstrated a differential regulation of target ILRs in GC at different stages of follicular development. Overall, these data provide a better understanding of the changes that could affect follicular development and ovulation during the postpartum period and lay the ground for further investigations.

Level of Bisphenol A in Follicular Fluid and Serum and Oocyte Morphology in Patients Undergoing IVF Treatment

Objective: To assess the correlation between the levels of BPA in the serum and follicular fluid (FF) using oocyte morphology. Materials and methods: In this cross-sectional research, oocyte, FF, and serum samples were obtained from a sample population consisting of 90 women undergone in vitro fertilization in Ganjavian Hospital in Dezful, Iran during October 2017-March 2018. The ELISA kit was utilized for the measurement of the BPA levels. In addition, oocyte morphology simultaneous with inverted optical microscopy. Results: Follicular fluid BPA levels had no significant effect on MII oocytes (p ≥ 0.05). However, the mean levels of degenerated oocytes and germinal vesicle (GV) were significantly higher in the women with high BPA levels in the FF (p ≤ 0.05). Moreover, the mean counts of MII oocytes and oocytes were significantly higher in the women with serum BPA levels of ≤ 50 ng/ml (p ≤ 0.05), while the mean count of GV oocytes was significantly higher in the women with serum BPA levels of ≥ 150 ng/ml (p ≤ 0.05). Conclusion: According to the results, higher FF BPA levels were associated with the higher counts of GVs and oocytes, while oocytes with higher maturity can be achieved in lower levels of BPA in the serum of patients.