Culture of human oocytes with granulocyte-macrophage colony-stimulating factor has no effect on embryonic chromosomal constitution

Comparison of the Effects of GMCSF-Containing and Traditional Culture Media on Embryo Development and Pregnancy Success Rates

OBJECTIVE

 The use of granulocyte macrophage colony-stimulating factor (GM-CSF)-containing medium, which is a commercial medium that is used for cultivation of embryos in in vitro fertilization (IVF) treatments, has been suggested to increase the efficiency of this procedure in patients with previous multiple unsuccessful attempts. In this retrospective study, we analyzed GM-CSF-containing embryo culture media compared with traditional culture media in terms of development of embryos, pregnancy, and ongoing pregnancy success and live birth rates.

METHODS

 This is a prospective case control study conducted in a single center. A total of 131 unexplained infertility patients were included in the study. A cohort of 69 patients whose embryos were cultured in GM-CSF-containing medium and a control group of 62 age-matched patients whose embryos were cultured in conventional Sage One Step medium were included in the study. The major study outcomes were achievement of pregnancy and ongoing pregnancy rate at 12 weeks of gestation.

RESULTS

 The pregnancy and ongoing pregnancy rates of the patients whose embryos were cultured in GM-CSF-containing medium were 39.13% and 36.23%, respectively. These were higher than the rates of the control group, which were 30.65% and 29.03%, respectively, although this difference was not statistically significant. In addition, the 5^th-day embryo transfer percentage in the GM-CSF group was higher than in the control group (34.78% versus 27.4%).

CONCLUSION

 The main findings of our study were that there was no difference between the GM-CSF-enhanced medium and the control group in terms of our major study outcomes. However, blastomere inequality rate and embryo fragmentation rates were lower in the GM-CSF group.

Granulocyte-macrophage colony-stimulating factor-containing medium treatment after thawing improves blastocyst-transfer outcomes in the frozen- thawed blastocyst-transfer cycle

PURPOSE

To determine whether granulocyte-macrophage colony-stimulating factor (GM-CSF)-containing medium could improve embryo-transfer outcomes in frozen-thawed blastocyst transfer.

METHODS

Patients who underwent frozen-thawed blastocyst transfer (430 women, aged 30-39 years, 566 cycles) were analyzed. Frozen-thawed blastocysts were cultured in GM-CSF-containing medium or control medium for 3-5 h, followed by transfer to the uterus. The embryo-transfer outcomes in the two groups were measured and compared, and a propensity score matching (1:1) method was used to balance the differences in baseline characteristics. We analyzed 213 matched samples.

RESULTS

In patients who underwent frozen-thawed blastocyst transfer with GM-CSF, the percentage of human chorionic gonadotropin-positive cases, biochemical pregnancies, clinical pregnancies, ongoing pregnancies, and live birth rates was 60.6%, 7.98%, 52.6%, 42.9%, and 40.9%, respectively, as compared with 45.1%, 3.29%, 41.8%, 31.1%, and 30.5%, respectively, for the control groups. The rates of human chorionic gonadotropin positivity (odds ratio [OR]: 1.87, 95% confidence interval: [CI]: 1.27-2.75), biochemical pregnancy (2.55, 1.04-6.29), clinical pregnancy (1.54, 1.05-2.27), ongoing pregnancy (1.64, 1.13-2.41), and live birth (1.67, 1.14-2.45) were significantly higher in the GM-CSF group than the control group. The incidence of pregnancy loss (22.3% vs. 27.0%) did not significantly differ between the groups.

CONCLUSION

The use of a GM-CSF-containing medium for blastocyst-recovery culture improved the live birth rate as a result of increased implantation rate in the frozen-thawed blastocyst-transfer cycle. The use of GM-CSF-containing medium following blastocyst thawing could be an effective choice for improving the blastocyst-transfer outcomes.

GM-CSF perturbs cell identity in mouse pre-implantation embryos

Growth factors became attractive candidates for medium supplementation to further improve the quality of embryo culture and to mimic in vivo nutrition. Granulocyte macrophage colony-stimulating factor (GM-CSF) is a cytokine influencing the maternal-fetal interface and supporting placental development in mouse and human. It is expressed in epithelial cells of the endometrium under the regulation of estrogens. The factor is already in clinical use and a large clinical trial showed that, if supplemented to an embryo culture medium, it leads to increased survival of embryos, especially in women with previous miscarriages. Animal and cell culture studies on isolated trophectoderm cells support an effect mainly on cellular expansion. Aim of this study was to investigate, if the supplementation of GM-CSF either in a human ART medium or in a mouse optimized medium, leads to a change in cell number and cell lineages in the early pre-implantation mouse embryo. Our data shows that mouse GM-CSF increased total cell numbers with increasing concentrations. This increase of cell number has not been found in embryos cultured in ART media with or without human GM-CSF (hGM-CSF) or in a mouse medium supplemented with different concentrations of hGM-CSF. The changes were caused by a marked difference in TE and primitive endoderm cell numbers but not due to a change in epiblast cell numbers. Additionally, results show an ectopic expression of NANOG among trophectoderm cells in both, human ART media (with and without GM-CSF) and at increasing concentrations in the mouse and the human GM-CSF supplemented media. In conclusion, we could show that GM-CSF has an effect on cell identity in mice, which might probably also occur in the human. Therefore, we would like to rare awareness that the use of supplements without proper research could bare risks for the embryo itself and probably also in the post-implantation phase.

GM-CSF (granulocyte macrophage colony-stimulating factor) supplementation in culture media for women undergoing assisted reproduction

BACKGROUND

GM-CSF (granulocyte macrophage colony-stimulating factor) is a growth factor that is used to supplement culture media in an effort to improve clinical outcomes for those undergoing assisted reproduction. It is worth noting that the use of GM-CSF-supplemented culture media often adds a further cost to the price of an in vitro fertilisation (IVF) cycle. The purpose of this review was to assess the available evidence from randomised controlled trials (RCTs) on the effectiveness and safety of GM-CSF-supplemented culture media.

OBJECTIVES

To assess the effectiveness and safety of GM-CSF-supplemented human embryo culture media versus culture media not supplemented with GM-CSF, in women or couples undergoing assisted reproduction.

SEARCH METHODS

We used standard methodology recommended by Cochrane. We searched the Cochrane Gynaecology and Fertility Group Trials Register, CENTRAL, MEDLINE, Embase, CINAHL, LILACS, DARE, OpenGrey, PubMed, Google Scholar, and two trials registers on 15 October 2019, checked references of relevant papers and communicated with experts in the field.

SELECTION CRITERIA

We included RCTs comparing GM-CSF (including G-CSF (granulocyte colony-stimulating factor))-supplemented embryo culture media versus any other non-GM-CSF-supplemented embryo culture media (control) in women undergoing assisted reproduction.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. The primary review outcomes were live birth and miscarriage rate. The secondary outcomes were clinical pregnancy, multiple gestation, preterm birth, birth defects, aneuploidy, and stillbirth rates. We assessed the quality of the evidence using GRADE methodology. We undertook one comparison, GM-CSF-supplemented culture media versus culture media not supplemented with GM-CSF, for those undergoing assisted reproduction.

MAIN RESULTS

We included five studies, the data for three of which (1532 participants) were meta-analysed. We are uncertain whether GM-CSF-supplemented culture media makes any difference to the live-birth rate when compared to using conventional culture media not supplemented with GM-CSF (odds ratio (OR) 1.19, 95% confidence interval (CI) 0.93 to 1.52, 2 RCTs, N = 1432, I² = 69%, low-quality evidence). The evidence suggests that if the rate of live birth associated with conventional culture media not supplemented with GM-CSF was 22%, the rate with the use of GM-CSF-supplemented culture media would be between 21% and 30%. We are uncertain whether GM-CSF-supplemented culture media makes any difference to the miscarriage rate when compared to using conventional culture media not supplemented with GM-CSF (OR 0.75, 95% CI 0.41 to 1.36, 2 RCTs, N = 1432, I² = 0%, low-quality evidence). This evidence suggests that if the miscarriage rate associated with conventional culture media not supplemented with GM-CSF was 4%, the rate with the use of GM-CSF-supplemented culture media would be between 2% and 5%. Furthermore, we are uncertain whether GM-CSF-supplemented culture media makes any difference to the following outcomes: clinical pregnancy (OR 1.16, 95% CI 0.93 to 1.45, 3 RCTs, N = 1532 women, I² = 67%, low-quality evidence); multiple gestation (OR 1.24, 95% CI 0.73 to 2.10, 2 RCTs, N = 1432, I² = 35%, very low-quality evidence); preterm birth (OR 1.20, 95% CI 0.70 to 2.04, 2 RCTs, N = 1432, I² = 76%, very low-quality evidence); birth defects (OR 1.33, 95% CI 0.59 to 3.01, I² = 0%, 2 RCTs, N = 1432, low-quality evidence); and aneuploidy (OR 0.34, 95% CI 0.03 to 3.26, I² = 0%, 2 RCTs, N = 1432, low-quality evidence). We were unable to undertake analysis of stillbirth, as there were no events in either arm of the two studies that assessed this outcome.

AUTHORS' CONCLUSIONS

Due to the very low to low quality of the evidence, we cannot be certain whether GM-CSF is any more or less effective than culture media not supplemented with GM-CSF for clinical outcomes that reflect effectiveness and safety. It is important that independent information on the available evidence is made accessible to those considering using GM-CSF-supplemented culture media. The claims from marketing information that GM-CSF has a positive effect on pregnancy rates are not supported by the available evidence presented here; further well-designed, properly powered RCTs are needed to lend certainty to the evidence.

Therapeutic role of granulocyte macrophage colony-stimulating factor (GM-CSF) in patients with persistent thin endometrium: A prospective and randomized study

OBJECTIVE

To assess the effect of granulocyte macrophage colony-stimulating factor (GM-CSF) on unresponsive thin (<7 mm) endometrium in women undergoing frozen-thawed embryo transfer.

METHODS

A single-center, randomized, prospective study enrolled 304 women with thin unresponsive endometrium from Shanghai Ninth People's Hospital between March 2017 and May 2018. Of them, 161 patients received an intrauterine infusion of GM-CSF and 143 patients served as controls. After hysteroscopy, a gel with or without GM-CSF was administered to fill the uterine cavity completely or up to 5 mL only. The primary outcome was confirmed pregnancy and secondary outcomes included endometrial thickness and implantation rate.

RESULTS

Patients who were administered GM-CSF had a significantly higher chemical pregnancy rate (35.3% vs 20.0%; P=0.009) and clinical pregnancy rate (28.6% vs 13.3%; P=0.005) compared with patients in the control group. Patients treated with GM-CSF had significantly higher endometrial thickness compared with controls (7.83 ± 1.45 mm vs 7.37 ± 0.70 mm, P=0.003).

CONCLUSION

GM-CSF therapy can effectively increase endometrial thickness and improve the clinical pregnancy rate in patients with persistent thin endometrium. The therapeutic role of GM-CSF for infertile women under in vitro fertilization and embryo transfer (IVF-ET) treatment can be further explored.

CHINESE CLINICAL TRIAL REGISTER

ChiCTR-IPR-17011242.

GM-CSF does not rescue poor-quality embryos: secondary analysis of a randomized controlled trial

Purpose

To evaluate implantation potential of cleavage-stage embryos cultured in medium containing 2 ng/ml granulocyte–macrophage colony-stimulating factor (GM-CSF) versus control medium, according to embryo morphological quality and then transferred on day 3.

Methods

Explorative secondary data analysis of a multicenter, randomized, placebo-controlled, double-blinded prospective study of 1149 couples with embryo transfer after IVF/ICSI. This analysis includes a subgroup of 422 subjects with either single-embryo transfer (SET, N = 286) or double-embryo transfer of two embryos with equivalent morphological quality (DET, N = 136). Implantation rate and live birth rate were assessed according to category of morphological embryo quality on day 3.

Results

Culture with GM-CSF did not increase the implantation rate for embryos classified as poor quality. A trend towards greater benefit of GM-CSF on implantation and survival until live birth for top-quality embryos (TQEs) compared with poor-quality embryos was observed, although not statistically significant. For TQEs, the percentage of transferred embryos resulting in a live born baby was: 40.9 ± 5.3% (GM-CSF) versus 30.5 ± 4.6% (control) (P = 0.24; odds ratio [OR] 1.43, 95% confidence interval [CI] 0.79–2.59), and for embryos with less than 6 cells at day 3 this same rate was: 7.4 ± 3.3% (GM-CSF) versus 12.0 ± 4.0% (control) (P = 0.26; OR 0.53, 95% CI 0.17–1.61).

Conclusion

This exploratory analysis is consistent with GM-CSF protecting morphologically normal embryos from culture-induced stress and does not support an effect of GM-CSF in rescuing poor-quality embryos.

ClinicalTrials.gov identifier: NCT00565747.

The incidence rate of unresponsive thin endometrium in frozen embryo transfer cycles: A case-series of therapy with granulocyte colony stimulating factor

Background

Treatment-resistant thin endometrium (TTE) during in-vitro fertilization is a relatively uncommon and challenging problem.

Objective

The primary aim of the study was to assess the TTE rate during frozen embryo transfer (FET) cycles and the secondary aim was to evaluate the effect of intrauterine instillation of granulocyte colony stimulating factor (G-CSF) in these cases.

Materials and Methods

In this cross-sectional study, all of the women who underwent FET cycles with hormonal endometrial preparation in Royan Institute from June 2015 to March 2018 were evaluated and all of the cases with TTE diagnosis (endometrial thickness < 7 mm after using high doses of estradiol) were included. In the eligible cases, 300 μgr of G-CSF was infused intrauterine. If the endometrium had not reached at least a 7-mm, a second infusion was prescribed within 48 hr later.

Results

During the study, 8,363 of FET cycles were evaluated and a total of 30 infertile patients (0.35%) with TTE diagnosis were detected. Finally, 20 eligible patients were included. The changes of endometrial thickness after G-CSF therapy were significant (p < 0.001); however, the endometrial thickness did not reach 7 mm in nine patients (45%) and the embryo transfer was canceled.

Conclusion

It was found that the rate of TTE during the FET cycle is very low and intrauterine perfusion of G-CSF has a potential effect to increase the endometrial thickness in these patients; however, the rate of cancellation was still high and poor pregnancy outcomes were observed.

The role of immunotherapy in in vitro fertilization: a guideline

Adjuvant immunotherapy treatments in in vitro fertilization (IVF) aim to improve the outcome of assisted reproductive technology (ART) in both the general ART population as well as subgroups such as patients with recurrent miscarriage or implantation failure. The purpose of this guideline is to evaluate the role of immunomodulating therapy in ART. Unfortunately, many of the evaluated therapies lack robust evidence from well-designed adequately powered randomized controlled trials to support their use. Immunotherapies reviewed in the present document are either not associated with improved live-birth outcome in IVF or have been insufficiently studied to make definitive recommendations.

The combination of calcium ionophore A23187 and GM-CSF can safely salvage aged human unfertilized oocytes after ICSI

PURPOSE

Artificial oocyte activation using calcium ionophores and enhancement of embryonic developmental potential by the granulocyte-macrophage colony-stimulating factor (GM-CSF) have already been reported. In this study, we evaluated the synergistic effect of these two methods on aged human unfertilized oocytes after intracytoplasmic sperm injection (ICSI). Then, we cultured the resulting embryos to the blastocyst stage and screened them for chromosomal abnormalities, to assess the safety of this protocol.

METHODS

Aged human oocytes deemed unfertilized after ICSI were activated, either by briefly applying the calcium ionophore A23187 alone (group A) or by briefly applying the ionophore and then supplementing the culture medium with recombinant human GM-CSF (rhGM-CSF) (group B). Next, the development was monitored in a time-lapse incubator system, and ploidy was analyzed by array comparative genomic hybridization (aCGH), after whole embryo biopsy and whole genome amplification. Differences between oocytes and resulting embryos in both groups were evaluated statistically.

RESULTS

Oocytes unfertilized after ICSI can be activated with the calcium ionophore A23187 to show two pronuclei and two polar bodies. Addition of rhGM-CSF in the culture medium of A23187-activated oocytes enhances their cleaving and blastulation potential and results in more euploid blastocysts compared to the culture medium alone.

CONCLUSIONS

This study shows that activating post-ICSI aged human unfertilized oocytes with a combination of a calcium ionophore and a cytokine can produce good-morphology euploid blastocysts.

Effects of granulocyte-macrophage colony-stimulating factor supplementation in culture medium on embryo quality and pregnancy outcome of women aged over 35 years

PURPOSE

The purpose of this study is to explore whether a low concentration of granulocyte-macrophage colony-stimulating factor (GM-CSF) supplementation in culture medium is beneficial to infertile women aged over 35 years.

METHODS

A retrospective cohort study was performed to analyze the embryo quality and pregnancy outcome of 212 controlled ovarian stimulation (COH) cycles with or without GM-CSF addition (n = 117 [GM-CSF, 0.2 ng/mL] vs n = 95 [control]).

RESULTS

No significant difference was observed in cleavage rate (96.2 vs 96.5 %), blastocyst formation rate (53.2 vs 54.0 %), good blastocyst rate (26.8 vs 26.8 %), or available embryo rate (54.2 vs 49.7 %) between the GM-CSF group and the control group. However, the average age of the GM-CSF group (38.41 ± 3.13 years) was significantly 1 year older than that of the corresponding control group (37.45 ± 2.74 years) (P < 0.05). GM-CSF addition greatly decreased the occurrence of biochemical pregnancy (55.6 % [control] vs 20.8 % [GM-CSF], P < 0.05). No case of neonatal malformation was observed in the present study.

CONCLUSION

Although no benefit of GM-CSF on embryo quality was observed, the addition of this factor significantly decreased the occurrence of chemical pregnancy of women aged over 35 years, indicating the role of GM-CSF in improving implantation competence of embryos derived from elderly infertile women.

Colony Stimulating Factors 1, 2, 3 and early pregnancy steps: from bench to bedside

Reproductive immunology applies general immunology principles to specialised targets, reproduction and development. The involvement of colony-stimulating factors (CSFs) in reproduction illustrates this. The CSF family includes CSF-1 or macrophage CSF (M-CSF), CSF-2 or granulocyte macrophage CSF (GM-CSF), and CSF-3 or granulocyte CSF (G-CSF). Each member has a specific localisation and timed expression in the reproductive tract with specific functions involving them in ovulation, embryo implantation, placentation and further embryonic development. They are used in reproductive medicine, either as biomarkers of oocyte quality and competence (follicular G-CSF), or to supplement embryo culture media with human recombinant GM-CSF, or they are used as an innovative therapy by using human recombinant G-CSF for infertile patients. Given fundamental considerations on CSFs and their strong implication in reproduction, this review aimed to detail the current knowledge for each member of the family to improve our understanding of their implication in the maternal-foetal cytokinic dialogue and in possibly preventing reproductive disorders.

Soluble ligands and their receptors in human embryo development and implantation

Extensive evidence suggests that soluble ligands and their receptors mediate human preimplantation embryo development and implantation. Progress in this complex area has been ongoing since the 1980s, with an ever-increasing list of candidates. This article specifically reviews evidence of soluble ligands and their receptors in the human preimplantation stage embryo and female reproductive tract. The focus will be on candidates produced by the human preimplantation embryo and those eliciting developmental responses in vitro, as well as endometrial factors related to implantation and receptivity. Pathways to clinical translation, including innovative diagnostics and other technologies, are also highlighted, drawing from this collective evidence toward facilitating joint improvements in embryo quality and endometrial receptivity. This strategy could not only benefit clinical outcomes in reproductive medicine but also provide broader insights into the peri-implantation period of human development to improve fetal and neonatal health.

Female tract cytokines and developmental programming in embryos

In the physiological situation, cytokines are pivotal mediators of communication between the maternal tract and the embryo. Compelling evidence shows that cytokines emanating from the oviduct and uterus confer a sophisticated mechanism for 'fine-tuning' of embryo development, influencing a range of cellular events from cell survival and metabolism, through division and differentiation, and potentially exerting long-term impact through epigenetic remodelling. The balance between survival agents, including GM-CSF, CSF1, LIF, HB-EGF and IGFII, against apoptosis-inducing factors such as TNFα, TRAIL and IFNg, influence the course of preimplantation development, causing embryos to develop normally, adapt to varying maternal environments, or in some cases to arrest and undergo demise. Maternal cytokine-mediated pathways help mediate the biological effects of embryo programming, embryo plasticity and adaptation, and maternal tract quality control. Thus maternal cytokines exert influence not only on fertility and pregnancy progression but on the developmental trajectory and health of offspring. Defining a clear understanding of the biology of cytokine networks influencing the embryo is essential to support optimal outcomes in natural and assisted conception.

Dose-dependent embryotrophic effect of recombinant granulocyte-macrophage colony-stimulating factor and brain-derived neurotrophic factor in culture medium for mouse preimplantation embryo

OBJECTIVE

To evaluate the dose effect of recombinant mouse granulocyte-macrophage colony-stimulating factor (rmGM-CSF) or brain-derived neurotrophic factor (BDNF) in culture medium on the development of in vitro fertilized mouse embryos.

METHODS

Mature oocytes were retrieved from superovulated female BDF1 mice and inseminated by sperm from male BDF1 mice. On day 1, two-cell stage embryos were divided and cultured until day 5 in the embryo maintenance medium supplemented with 0, 1, 2, 5, or 10 ng/mL of rmGM-CSF or supplemented with 0, 5, 10, or 20 ng/mL of BDNF. Blastocyst formation rate and their cell numbers were assessed.

RESULTS

The blastocyst formation rate and the total cell count in blastocyst was similar in all the rmGM-CSF treatment groups when compared with the control. However, the blastocyst formation rate and the total cell count was significantly higher in the group supplemented with 10 ng/mL of BDNF compared with the control (63.9%, 45.8±11.5 vs. 52.3%, 38.0±6.8; P<0.05, respectively).

CONCLUSION

Supplementation of 10 ng/mL of BDNF enhanced the developmental potential of mouse preimplantation embryos, but supplementation of rmGM-CSF did not.

IVF culture media: past, present and future

BACKGROUND

The advances in the world of IVF during the last decades have been rapid and impressive and culture media play a major role in this success. Until the 1980s fertility centers made their media in house. Nowadays, there are numerous commercially available culture media that contain various components including nutrients, vitamins and growth factors. This review goes through the past, present and future of IVF culture media and explores their composition and quality assessment.

METHODS

A computerized search was performed in PubMed regarding IVF culture media including results from 1929 until March 2014. Information was gathered from the websites of companies who market culture media, advertising material, instructions for use and certificates of analysis. The regulation regarding IVF media mainly in the European Union (EU) but also in non-European countries was explored.

RESULTS

The keyword 'IVF culture media' gave 923 results in PubMed and 'embryo culture media' 12 068 results dating from 1912 until March 2014, depicting the increased scientific activity in this field. The commercialization of IVF culture media has increased the standards bringing a great variety of options into clinical practice. However, it has led to reduced transparency and comparisons of brand names that do not facilitate the scientific dialogue. Furthermore, there is some evidence suggesting that suboptimal culture conditions could cause long-term reprogramming in the embryo as the periconception period is particularly susceptible to epigenetic alterations. IVF media are now classified as class III medical devices and only CE (Conformité Européene)-marked media should be used in the EU.

CONCLUSION

The CE marking of IVF culture media is a significant development in the field. However, the quality and efficiency of culture media should be monitored closely. Well-designed randomized controlled trials, large epidemiological studies and full transparency should be the next steps. Reliable, standardized models assessing multiple end-points and post-implantation development should replace the mouse embryo assay. Structured long-term follow-up of children conceived by assisted reproduction technologies and traceability are of paramount importance.

Granulocyte macrophage colony stimulating factor supplementation in culture media for subfertile women undergoing assisted reproduction technologies: a systematic review

Granulocyte macrophage colony stimulating factor (GM-CSF) is a cytokine/growth factor produced by epithelial cells that exerts embryotrophic effects during the early stages of embryo development. We performed a systematic review, and six studies that were performed in humans undergoing assisted reproduction technologies (ART) were located. We wanted to evaluate if embryo culture media supplementation with GM-CSF could improve success rates. As the type of studies and the outcome parameters investigated were heterogeneous, we decided not to perform a meta-analysis. Most of them had a trend favoring the supplementation with GM-CSF, when outcomes were measured in terms of increased percentage of good-quality embryos reaching the blastocyst stage, improved hatching initiation and number of cells in the blastocyst, and reduction of cell death. However, no statistically significant differences were found in implantation and pregnancy rates in all apart from one large multicenter trial, which reported favorable outcomes, in terms of implantation and live birth rates. We propose properly conducted and adequately powered randomized controlled trials (RCTs) to further validate and extrapolate the current findings with the live birth rate to be the primary outcome measure.

The effect of GM-CSF on development and aneuploidy in murine blastocysts

BACKGROUND

Growth factors and cytokines are present in small quantities in the oviduct and uterus and some are synthesized by the growing embryo. Granulocytes-macrophage colony-stimulating factor (GM-CSF) is known as an important regulator, which enhances cell proliferation and reduces apoptosis in developing blastocysts, during normal fetal and placental development. The purpose of this study is to investigate whether adding GM-CSF to the culture media affects blastulation or the chromosomal status of mouse embryos.

METHODS

Murine embryos were cultured in vitro from the 2-cell stage until the blastocyst stage in the presence of different concentrations of GM-CSF of 0 ng/ml (control), 1, 2, 5 and 10 ng/ml. The development of each embryo was noted and the embryos were then spread for fluorescence in situ hybridization (FISH) using locus-specific probes (LSI) for chromosomes 2, 11 and 16 in all embryos.

RESULTS

No difference in the blastulation potential was noted with the addition of 1 and 2 ng/ml of GM-CSF compared with the controls, but there was a significant decrease (P < 0.001) in the blastulation rate in the 5 and 10 ng/ml concentrations. The rate of mosaicism/aneuploidy noted in all GM-CSF groups (1, 2, 5 and 10 ng/ml) was slightly higher than in the control group (0 ng/ml GM-CSF) but the differences were not significant. In the mosaic embryos from the GM-CSF cultured groups, the percentage of aneuploid cells was statistically higher than in the control group.

CONCLUSIONS

GM-CSF exerted a negative impact on blastocyst development at higher concentrations. GM-CSF did not affect the rates of mosaicism/aneuploidy, but did increase the percentage of aneuploid cells within the mosaic embryos. Adding GM-CSF to the culture media for clinical use requires further studies either on human or animal models to evaluate its long-term effects.