Increased SCF in Follicular Fluid and Granulosa Cells Positively Correlates With Oocyte Maturation, Fertilization, and Embryo Quality in Humans

Serum levels of stem cell factor for predicting embryo quality

We evaluated whether serum stem cell factor (s-SCF) levels just prior to ovulation induction could indicate the ability to develop a top-quality (TQ) blastocyst by day 5. We investigated patients with normal ovarian reserve (NOR), polycystic ovary syndrome (PCOS), diminished ovarian reserve (DOR), or mild endometriosis. Our pilot research suggests a correlation between s-SCF levels and the ability to form TQ blastocysts in patients with mild endometriosis. This significant statistical difference (p < 0.05) was noted between mild endometriosis patients for whom a TQ blastocyst was obtained and those for whom it was not possible, as measured on the 8th day of stimulation and the day of oocyte retrieval. The mean SCF levels in the serum of these women on the 8th day were at 28.07 (± 2.67) pg/ml for the TQ subgroup and 53.32 (± 16.02) pg/ml for the non-TQ subgroup (p < 0.05). On oocyte retrieval day it was 33.47 (± 3.93) pg/ml and 52.23 (± 9.72) pg/ml (p < 0.05), respectively.

Stem cell factor's role in enhancing the quality of fertilized and cloned porcine embryos for improved embryonic stem cell derivation

Stem cell factor (SCF), a cytokine growth factor, is expressed in various tissues of the male and female reproductive organs, including the testis, ovary, and endometrium. Its primary function involves cell survival, differentiation, and proliferation, achieved through its binding to the c-kit receptor. This study aimed to scrutinize the effects of SCF treatment during in vitro culture (IVC) on both the developmental potential and the efficiency of establishing embryonic stem cells (ESCs) from fertilized and cloned porcine embryos. The rates of cleavage and blastocyst formation exhibited no significant differences between fertilized and cloned embryos, even with the addition of SCF. However, it's worth noting that embryos cloned with Cloud eGFP as donor cells demonstrated notably increased rates of hatched blastocysts when treated with SCF, and this increase was statistically significant (p < 0.05). Furthermore, following the complete dissection of the blastocysts, although there was no significant difference in the SCF-treated group, the area of expansion was significantly reduced (p < 0.01) in the group treated with the antagonistic blocker (ACK2) compared to both the control and SCF-treated groups. These outcomes suggest that the SCF/c-kit signaling pathway might play a pivotal role in embryo implantation. As anticipated, the efficiency of deriving ESCs was significantly higher (p < 0.01) in the group subjected to SCF treatment (12.82 ± 1.02%) compared to the control group (5.41 ± 2.25%). In conclusion, this study highlights the crucial role of SCF in enhancing the quality of porcine embryos, a vital step in obtaining high-quality ESCs.

Does the Use of the "Proseek® Multiplex Inflammation I Panel" Demonstrate a Difference in Local and Systemic Immune Responses in Endometriosis Patients with or without Deep-Infiltrating Lesions?

Endometriotic lesions are able to infiltrate surrounding tissue. This is made possible partly by an altered local and systemic immune response that helps achieve neoangiogenesis, cell proliferation and immune escape. Deep-infiltrating endometriosis (DIE) differs from other subtypes through the invasion of its lesions over 5 mm into affected tissue. Despite the invasive nature of these lesions and the wider range of symptoms they can trigger, DIE is described as a stable disease. This elicits the need for a better understanding of the underlying pathogenesis. We used the "Proseek^® Multiplex Inflammation I Panel" in order to simultaneously detect 92 inflammatory proteins in plasma and peritoneal fluid (PF) of controls and patients with endometriosis, as well as in particular patients with DIE, in order to gain a better insight into the systemically and locally involved immune response. Extracellular newly identified receptor for advanced gycation end-products binding protein (EN-RAGE), C-C motif Chemokine ligand 23 (CCL23), Eukaryotic translation initiation factor 4-binding protein 1 (4E-BP1) and human glial cell-line derived neurotrophic factor (hGDNF) were significantly increased in plasma of endometriosis patients compared to controls, whereas Hepatocyte Growth factor (HGF) and TNF-related apoptosis inducing ligand (TRAIL) were decreased. In PF of endometriosis patients, we found Interleukin 18 (IL-18) to be decreased, yet Interleukin 8 (IL-8) and Interleukin 6 (IL-6) to be increased. TNF-related activation-induced cytokine (TRANCE) and C-C motif Chemokine ligand 11 (CCL11) were significantly decreased in plasma, whereas C-C motif Chemokine ligand 23 (CCL23), Stem Cell Factor (SCF) and C-X-C motif chemokine 5 (CXCL5) were significantly increased in PF of patients with DIE compared to endometriosis patients without DIE. Although DIE lesions are characterized by increased angiogenetic and pro-inflammatory properties, our current study seems to support the theory that the systemic immune system does not play a major role in the pathogenesis of these lesions.

Associations of circulation levels of cytokines with birthweight, preterm birth, spontaneous miscarriages, and stillbirth: A Mendelian randomization analysis

Background: The association between immune imbalances and adverse pregnancy outcomes has been extensive investigated by observational studies, but remain unclear. Thus, this study aimed to establish the causality of the circulation levels of cytokines on adverse pregnancy outcomes, such as offspring's birthweight (BW), preterm birth (PTB), spontaneous miscarriage (SM), and stillbirth (SB). Methods: Two-sample Mendelian randomization (MR) analysis was employed to investigate potential causal relations between 41 cytokines and pregnancy outcomes on the basis of previously published GWAS datasets. Multivariable MR (MVMR) analysis was implemented to investigate the effect of the composition of cytokine networks on the pregnancy outcomes. Potential risk factors were further estimated to explore the potential mediators. Results: Genetic correlation analysis based on large GWAS data sources revealed that genetically predicted MIP1b (β = -0.027, S.E. = 0.010, p = 0.009) and MCSF (β = -0.024, S.E. = 0.011, p = 0.029) were associated with reduced offspring's BW, MCP1 (OR: 0.90, 95% CI: 0.83-0.97, p = 0.007) was associated with reduced SM risk, SCF (β = -0.014, S.E. = 0.005, p = 0.012) associated with decreased number of SB in MVMR. The univariable MR showed that GROa (OR: 0.92, 95% CI: 0.87-0.97, p = 0.004) was associated with decreased PTB risk. Except for the MCSF-BW association, all above associations surpassed the Bonferroni corrected threshold. The MVMR results revealed that MIF, SDF1a, MIP1b, MCSF and IP10 composed cytokine networks, associated with offspring's BW. Risk factors analysis indicated that the above causal associations might be mediated by smoking behaviors. Conclusion: These findings suggest the causal associations of several cytokines with adverse pregnancy outcomes, which were potentially mediated by smoking and obesity. Some of the results did not been corrected through multiple tests and larger samples verification is required in further studies.

Aberrant BMP15/HIF-1α/SCF signaling pathway in human granulosa cells is involved in the PCOS related abnormal follicular development

AIMS

To investigate the regulatory mechanism of SCF expression in human GCs of PCOS related follicles.

MATERIALS AND METHODS

SCF, BMP15 and HIF-1α were evaluated in human serums, follicular fluids (FFs) and GCs, which were collected from 69 PCOS patients and 74 normal ovulatory patients. KGN cell line was used in this study.

RESULTS

Our results showed that the rate of MII oocyte and 2PN fertilization was lower in PCOS group, though PCOS patients retrieved much more oocytes. The level of BMP15 in FF and the level of SCF in serum and FF were also lower in PCOS patients. We found a weakened expression of HIF-1α and SCF in GCs from PCOS patients when compared with the non-PCOS patients. The expression of HIF-1α and SCF was significantly increased in KGN cells after treating cells with rhBMP15, however, this promotion effects of BMP15 on HIF-1α and SCF expression were obviously abolished by co-treatment with BMP-I receptor inhibitor (DM). Moreover, knock down of HIF-1α expression in KGN cells significantly reduced the expression of SCF in human GCs, in spite of activating BMP15 signaling pathway.

CONCLUSIONS

The present study suggest that BMP15 could induce SCF expression by up-regulating HIF-1α expression in human GCs, the aberrance of this signaling pathway might be involved in the PCOS related abnormal follicular development.

Maternal preconception phthalate metabolite concentrations in follicular fluid and neonatal birth weight conceived by women undergoing in vitro fertilization

Exposure to phthalates during gestation has been associated with decreased birth weight among offspring. However, the associations between preconception phthalate metabolites in follicular fluid (FF) and offspring birth weight among women undergoing in vitro fertilization (IVF) remain largely unknown. Here, we explored the associations between preconception phthalate metabolite concentrations in FF and the birth weights of singletons and twins among women undergoing IVF. We recruited 147 female participants who gave birth to 90 singletons and 57 twin infants at the Reproductive Medicine Center, Tongji Hospital, Wuhan, between November and December 2016. Each participant was asked to complete a questionnaire at the time of recruitment and provide a FF sample on the day of oocyte retrieval. The FF concentrations of eight phthalate metabolites were determined using high-performance liquid chromatography and tandem mass spectrometry. Birth outcomes were abstracted from medical records. The associations between phthalate metabolites in FF and birth weights of the singleton and twin groups were evaluated using generalized linear models (GLMs). We found that birth weight in the twin group had negative dose-response associations with maternal preconception monobenzyl phthalate (MBzP) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) in FF (both P for trends < 0.05) and that birth weight in the singleton group had positive dose-response associations with monoethyl phthalate (MEP) and mono(2-ethyl-5 hydroxyhexyl) phthalate (MEHHP) in FF (both P for trends < 0.05). These associations persisted when we modeled as continuous variables. In addition, we observed male-specific association between decreased twin birth weight and MEOHP and MBzP and a female-specific associations between increased singleton birth weight and MEP, MEHHP and the sum of di(2-ethylhexyl) phthalate (∑DEHP) (all P for interactions < 0.05). Preconception phthalate metabolites in maternal FF may affect the birth weights of both singleton and twin newborns.

Effect of Human Testicular Cells Conditioned Medium on In Vitro Maturation and Morphology of Mouse Oocytes

Background

Testicular cell conditioned medium (TCCM) has been shown to induce female germ cell development in vitro from embryonic stem cells (ESCs). Testicular cells (TCs) secrete a variety of growth factors such as growth differentiation factor-9 (GDF-9), bone morphogenetic protein 4 (BMP-4), stem cell factor (SCF), leukemia inhibitory factor (LIF), and other, that could improve oocyte maturation. Here we have investigated the effect of human TCCM (hTCCM) on in vitro maturation (IVM) and morphology of mouse oocytes.

Materials and Methods

In this experimental study, 360 germinal vesicle (GV) oocytes were obtained from NMRI mice, aged 4-6 weeks that had received 5 IU pregnant mare's serum gonadotropin (PMSG) 48 hours before. GV oocytes were subjected to IVM. 120 GV oocytes were cultured in each medium; hTCCM as the test group, DMEM + 20%FBS as the control group and Ham’s F10 + HFF medium as the sham group. The rates of the IVM and perivi- telline space (PVS) changes were recorded at 8, 16 and 24 hours after culture. The metaphase II (MII) oocytes were subjected for in vitro fertilization (IVF) and the fertilization rate was evaluated after 1, 2, and 3 days.

Results

There was a significant difference between the maturation rates in hTCCM (31.67% MII) and the control [0% MII, P<0.05, (7.5% MI, 52.5% deg. and 40%GV)] groups but there was not a significant difference between the maturation rates in hTCCM and the sham group (53.33% MII, P>0.05). IVF success rate for MII oocytes obtained from IVM in the hTCCM group was 28.94% (n=11). Our data showed that hTCCM is an effective medium for GV oocyte growth and maturation compared to the control medium.

Conclusion

Our findings show that TCCM supports oocyte IVM in mice and affect oocyte morphology.

The Factors and Pathways Regulating the Activation of Mammalian Primordial Follicles in vivo

Mammalian ovaries consist of follicles as basic functional units. Each follicle comprised an innermost oocyte and several surrounding flattened granulosa cells. Unlike males, according to the initial size of the primordial follicle pool and the rate of its activation and depletion, a female's reproductive life has been determined early in life. Primordial follicles, once activated, will get into an irreversible process of development. Most follicles undergo atretic degeneration, and only a few of them could mature and ovulate. Although there are a lot of researches contributing to exploring the activation of primordial follicles, little is known about its underlying mechanisms. Thus, in this review, we collected the latest papers and summarized the signaling pathways as well as some factors involved in the activation of primordial follicles, hoping to lead to a more profound understanding of the cellular and molecular mechanisms of primordial follicle activation.

LncRNA Gm2044 promotes 17β-estradiol synthesis in mpGCs by acting as miR-138-5p sponge

Long noncoding RNAs (lncRNAs) have been demonstrated to play vital roles in mammalian reproduction. Our previous research revealed that lncRNA Gm2044 is highly expressed in mouse spermatocytes and regulates male germ cell function. The gene annotation database BioGPS shows that Gm2044 is not only highly expressed in testicular tissue but also in ovarian tissue, which suggests that Gm2044 may be involved in female reproductive development. In this study, we confirmed that lncRNA Gm2044 promotes 17β-estradiol synthesis in mouse pre-antral follicular granulosa cells (mpGCs). Furthermore, bioinformatics methods, western blot, and the luciferase assay proved that Gm2044 functions as a miR-138-5p sponge to inhibit the direct target of miR-138-5p, Nr5a1, which enhances 17β-estradiol synthesis through cyp19a1 activation. Taken together, our results provide an insight into the mechanistic roles of lncRNA Gm2044 for 17β-estradiol synthesis by acting as competing-endogenous RNAs to modulate the function of mpGCs. Studying the potential lncRNAs, which regulate estradiol release, will be beneficial for the diagnosis and treatment of steroid hormone-related disease.

Serum and follicular fluid Stem Cell Factor assay in IVF poor responder and normal responder patients: a predictive biomarker of oocyte retrieval

OBJECTIVE

The aim of the study is to investigate serum stem cell factor (SCF) concentrations as potential biomarker for oocyte retrieval efficiency in IVF patients with poor prognosis.

METHODS

A pilot case-control study was performed on 30 poor and 30 normal responders that were stimulated with antagonist protocol. SCF concentrations were evaluated in samples of serum and follicular fluid obtained by all patients on the day of oocyte retrieval. At the time of oocyte retrieval, follicular fluid from at least two follicles ≥ 14 mm and two follicles < 14 mm was collected for SCF determination.

RESULTS

We did not find any statistical difference when comparing serum and follicular fluid levels of SCF in both poor- and normal-responder patients, the same results were achieved when poor-responder patients were stratified according to the number of MII oocytes retrieved. Moreover, levels of SCF (OR 1.000, 0.994-1.006) or in follicular fluid from ovarian follicles ≥ 14 mm (OR 0.995, CI 0.989-1.001) or from ovarian follicles < 14 mm (OR 1.003, CI 0.999-1.0069), were not significantly associated with the chances of ongoing pregnancies in poor-responder patients.

CONCLUSION

SCF was unable to predict oocyte retrieval efficiency or the chances of reaching embryo transfer.

Follicular factors determining granulosa cell number and developmental competence of porcine oocytes

PURPOSE

Granulosa cell (GC) number in follicles is a simple characteristic of follicles. The present study examined the hypothesis that follicular fluid (FF) determines GC number and oocyte developmental ability and revealed the molecular background determining the number of follicular GCs.

METHODS

FF was collected from antral follicles (3-5 mm in diameter), after which the number of GCs per follicle was determined for each donor gilt using real time PCR targeting single copy gene. GCs were analyzed by next-generation RNA sequencing and IPA pathway analysis.

RESULTS

When oocyte cumulus cell-oocyte-complexes (COCs) were cultured in maturation medium containing 10% of each individual FF, the rate of development to the blastocyst stage was significantly correlated with the number of GCs in the donor gilt. In addition, when GCs were cultured in medium containing FF, the proliferative activity of the GCs was also significantly correlated to the number of GCs in the donor gilt. Moreover, when the FFs were categorized based on the number of GCs in the follicle, it was found that supplementation of culture media with GC-rich FF improved the developmental ability of oocytes compared to those supplemented with GC-poor FF. RNA sequencing and a pathway analysis of GCs from GC-rich and -poor follicles revealed the key regulatory pathway determining GC number in follicles.

CONCLUSION

GC number may be a useful marker for "good" follicles and oocytes, and the characteristics of the FFs determine granulosa cell number and oocyte developmental ability.

Non-esterified fatty acid-associated ability of follicular fluid to support porcine oocyte maturation and development

Purpose

The effect of supplementing maturation medium with follicular fluid (FF) was examined according to its non‐esterified fatty acid (NEFA) content or with a fatty acid mixture (FA‐Mix) on the developmental competence of oocytes, as well as the mitochondrial quality and quantity in the oocytes and cumulus cells.

Method

Porcine oocytes from a slaughterhouse were used.

Results

The FF or FA‐Mix in maturation medium increased the lipid content in both the oocytes and the cumulus cells, but the adenosine triphosphate content was differentially affected. The FF supplementation increased the mitochondrial DNA copy number, survival of cumulus cells, and rate of oocyte development to the blastocyst stage, whereas the FA‐Mix supplementation did not show these effects. The expression levels of GPC4,PFKP,PRDX3, and TFAM in the cumulus cells increased after FF supplementation, but the expression of GJA1 decreased, compared with the cells that were cultured without FF.

Conclusion

Adding FF and FA‐Mix to the maturation medium increased the lipid content in the oocytes and cumulus cells. The effects of FF on the cumulus cells and oocytes were not observed after FA‐Mix supplementation, indicating that the concentration of the NEFAs in the FF are closely associated with an ability to support oocyte maturation and the metabolism of cumulus cells and oocytes.