Cell-free mitochondrial DNA in human follicular fluid: a promising bio-marker of blastocyst developmental potential in women undergoing assisted reproductive technology

Leukemia inhibitory factor supplementation during in vitro maturation enhances bovine oocyte maturation and somatic cloned embryo development

Somatic cell nuclear transfer (SCNT) plays a crucial role in animal reproduction and genetic engineering, especially in the breeding of high-yield dairy cows. However, the application of SCNT technology faces numerous challenges, particularly the low efficiency and high abortion rates during the in vitro maturation phase. These issues lead to reduced implantation rates of cloned embryos, affecting overall reproductive efficiency. Therefore, enhancing the quality of in vitro maturation media has become an essential approach to improve in vitro production efficiency. This study aimed to investigate the effects of leukemia inhibitory factor (LIF) on bovine oocyte maturation and cloned embryo implantation rates. We observed a significant increase in oocyte maturation rates by supplementing 25 ng/mL LIF into the maturation medium. Subsequently, we generated SCNT embryos using LIF-treated oocytes and conducted activation and culture experiments. The results indicated that LIF could enhance the differentiation capabilities of SCNT embryos and exert an anti-apoptotic effect during early embryonic development. Specifically, the supplementation of LIF not only improved the nuclear maturation rates of oocytes but also enhanced cytoplasmic maturation characteristics, such as mitochondrial membrane potential and endoplasmic reticulum distribution. Furthermore, LIF-treated oocytes exhibited higher cell numbers and lower apoptosis rates in SCNT embryos, indicating its crucial role in embryo quality control. Ultimately, we found that LIF significantly improved the implantation efficiency of cloned embryos, particularly during the early stages of pregnancy following embryo transfer. This finding provides new insights into improving the success rates of SCNT technology and lays the groundwork for future research, especially in exploring the effects of other growth factors and cytokines on oocyte maturation and embryo development.

First follicular fluid cf-mtDNA sequencing unveils ovarian stimulation-induced mutations impacting oocyte quality and IVF success

PURPOSE

Cell-free mitochondrial DNA (cf-mtDNA) has emerged as a promising non-invasive method to predict embryo implantation potential. This study presents the first sequencing of cf-mtDNA in follicular fluid, aiming to explore the impact of ovarian stimulation treatment on the accumulation of mtDNA mutations and assess their implications for IVF outcomes.

METHODS

We selected 24 women aged 27 to 35 from the Assisted Reproduction Unit based on inclusion criteria requiring them to be undergoing their first IVF cycle without known infertility issues. For each participant, blood samples were collected prior to ovarian stimulation, and follicular fluid samples were obtained at the time of oocyte retrieval. Long-PCR amplification and next-generation sequencing were used to identify mtDNA mutations.

RESULTS

Ovarian stimulation-induced mtDNA mutations in follicular fluid were identified primarily in the D-loop region of the mitochondrial genome. These mutations were correlated with low oocyte counts and poor embryo quality, ultimately reducing IVF success rates. The accumulation of these mutations followed a time-dependent pattern, with longer stimulation durations resulting in higher mutation rates and lower pregnancy outcomes. Prolonged stimulations may exacerbate oxidative stress, negatively impacting oocyte quality.

CONCLUSIONS

By introducing the first sequencing of follicular fluid cf-mtDNA, this study establishes a direct link between ovarian stimulation-induced mtDNA mutations and reduced IVF efficacy, highlighting them as non-invasive biomarkers for predicting IVF outcomes. Future research may focus on optimizing stimulation protocols or incorporating antioxidants to minimize mtDNA mutations, improving oocyte quality and overall IVF success rates for patients.

The role of granulosa cells in oocyte development and aging: Mechanisms and therapeutic opportunities

Granulosa cells (GCs) are essential for oocyte maturation, providing metabolic support, hormonal signaling, and structural integrity critical to successful follicular development. However, advancing age disrupts these functions, driven by factors such as increased oxidative stress, mitochondrial dysfunction, and transcriptomic and proteomic alterations. These age-related changes in GCs contribute to compromised oocyte quality, diminished follicular support, and a decline in fertility, particularly in women of advanced maternal age. This review highlights recent progress in understanding the pivotal roles of GCs in maintaining oocyte health, with a focus on the mechanisms underlying their aging-related dysfunction. Furthermore, we explore promising therapeutic strategies, including antioxidant therapies, metabolic modulators, and GC-based rejuvenation techniques, aimed at mitigating the impacts of reproductive aging. By consolidating and analyzing existing research, this review provides valuable perspectives on fertility preservation and factors shaping reproductive outcomes in women of advanced maternal age.

The mitochondrial DNA copy number and ovary-related reproductive disorders: A bidirectional two-sample Mendelian randomization study

OBJECTIVE

In the present study, a bidirectional two-sample Mendelian randomization approach was utilized to explore potential causal relationships between mitochondrial DNA copy number (mtDNA-CN) and ovary-related reproductive disorders (ORRDs), including ovarian dysfunction, ovarian cyst, polycystic ovary syndrome (PCOS), premature ovarian failure (POF) and ovarian endometriosis.

METHODS

Genetic associations with mtDNA-CN were obtained from three genome-wide association study (GWAS) summary statistics from the UK Biobank, and ORRD data were investigated using summary statistics from the FinnGen cohort. Single nucleotide polymorphisms (SNPs) correlated with mtDNA-CN were selected as genetic instrumental variables (IVs) to estimate the causal effect of mtDNA-CN on ORRDs using the inverse-variance weighted (IVW) method with heterogeneity and pleiotropy analysis, and we repeated this in the opposite direction using instruments for ORRDs.

RESULTS

We found that the genetically predicted mtDNA was indicative of increased levels of PCOS (OR = 1.16; P < 0.001) and ovarian endometriosis (OR = 1.25; P = 0.007) in the IVW analysis and was not associated with the risk of other ORRDs. In the reverse direction, genetically predicted ORRDs were not associated with mtDNA-CN levels in the IVW analysis. Sensitivity and replication analyses showed the results to be stable.

CONCLUSION

We found that mtDNA-CN may increase the risk of PCOS and ovarian endometriosis. This may have implications for mtDNA-CN as a biomarker for these conditions in clinical practice.

Seminal cell-free DNA as a potential marker for in vitro fertility of Nellore bulls

PURPOSE

This study aimed to identify a marker for freezability and in vitro fertility of sperm samples before freezing.

METHODS

Semen was collected from nine Nelore bulls; half of the ejaculate was used for seminal plasma cell-free DNA (cfDNA) quantification, and the other half was cryopreserved. Evaluation of sperm movement using computer-assisted semen analysis and plasma membrane integrity and stability, acrosomal integrity, apoptosis, and mitochondrial potential using flow cytometry were performed on fresh and frozen/thawed semen at 0, 3, 6, and 12 h after thawing. Frozen/thawed sperm was also used for in vitro embryo production. cfDNA was extracted from each bull, and the total DNA and number of cell-free mitochondrial DNA (cfmtDNA) copies were quantified. Semen from each animal was used for IVF, and cleavage, blastocyst formation, and cell counts were evaluated.

RESULTS

Two groups were formed and compared based on the concentrations of cfDNA and cfmDNA present: low-cfDNA and high-cfDNA and low-cfmtDNA and high-cfmtDNA. Up to 12 h post-thawing, there were no differences between the groups in the majority of the sperm parameters evaluated. Cleavage, day 6 and 7 blastocyst rates, and the number of cells were higher in the high cfDNA group than in the low cfDNA group. Similar results were observed for cfmtDNA, except for the number of cells, which was similar between the groups.

CONCLUSION

The concentration of cfDNA and the relative number of copies of cfmtDNA in seminal plasma cannot predict the freezability of semen but can be used to predict in vitro embryo production.

Evaluation of Oxidative and Nitrosative Stress Markers Related To Inflammation in The Cumulus Cells and Follicular Fluid of Women Undergoing Intracytoplasmic Sperm Injection: A Prospective Study

BACKGROUND

Oxidative/nitrosative stress in the oocyte microenvironment could have an impact on intracytoplasmic sperm injection (ICSI) outcomes. The presence of reactive oxygen species (ROS) and reactive nitrogen species (RNS) can stimulate the secretion of pro-inflammatory cytokines, leading to chronic inflammation and potentially affecting embryo as well as oocyte quality. This study aimed to examine the relationship of lipid peroxidation [measured by the malondialdehyde (MDA) assay] with protein carbonyl [measured by the 2,4 dinitrophenylhydrazine (DNPH) assay] levels in cumulus cells (CCs), as well as nitric oxide (NO), peroxynitrite (ONOO-), and C-reactive protein (CRP) levels in follicular fluid (FF). The potential relationship of these levels with ICSI outcome was also evaluated.

MATERIALS AND METHODS

In this prospective study, 63 FF samples and their corresponding CCs were collected for ICSI procedures. Spectrophotometry was used to assess levels of DNPH, MDA, NO, and ONOO-. CRP levels were evaluated using an immunoturbidimetric assay.

RESULTS

The patients under 37 years with normal ovarian reserve had significantly lower levels of MDA, DNPH, NO, ONOO-, and CRP compared to those over 37 years. Additionally, we observed higher levels of MDA, DNPH, NO, ONOO-, and CRP in the group with an oocyte maturity rate of less than 60%. No significant difference was observed between the DNPH levels and factors such as infertility duration, embryo quality, pregnancy, or the number of retrieved oocytes. A higher level of MDA, NO, ONOO-, and CRP was found to be significantly related to the lower number of retrieved oocytes, longer periods of infertility, poor embryo quality, and negative pregnancy outcomes.

CONCLUSION

Oxidative/nitrosative stress, linking to inflammation in the oocyte microenvironment, can be considered as a potentially useful biomarker for assessing the development and competence of oocytes and embryos and predicting ICSI outcomes.

The Diagnostic, Prognostic, and Therapeutic Potential of Cell-Free DNA with a Special Focus on COVID-19 and Other Viral Infections

Cell-free DNA (cfDNA) in human blood serum, urine, and other body fluids recently became a commonly used diagnostic marker associated with various pathologies. This is because cfDNA enables a much higher sensitivity than standard biochemical parameters. The presence of and/or increased level of cfDNA has been reported for various diseases, including viral infections, including COVID-19. Here, we review cfDNA in general, how it has been identified, where it can derive from, its molecular features, and mechanisms of release and clearance. General suitability of cfDNA for diagnostic questions, possible shortcomings and future directions are discussed, with a special focus on coronavirus infection.

The Ratio of cf-mtDNA vs. cf-nDNA in the Follicular Fluid of Women Undergoing IVF Is Positively Correlated with Age

Age-related mitochondrial markers may facilitate the prognosis of artificial reproductive technology outcomes. In this report, we present our study concerning the ratio of cf-mtDNA/cf-nDNA, namely the amount of cell-free mitochondrial DNA relative to cell-free nuclear DNA, in the follicular fluid (FF) of women undergoing IVF, aiming to generate a molecular fingerprint of oocyte quality. The values of this ratio were measured and compared among three groups of women (101 in total): (A) 31 women with polycystic ovary syndrome (PCOS), (B) 34 women younger than 36 years, and (C) 36 women older than 35 years of age. Real-time quantitative PCR (qPCR) was performed to quantify the ratio by using nuclear- and mitochondrial-specific primers and analyzed for potential correlation with age and pregnancy rate. Our analysis showed that the level of FF-cf-mtDNA was lower in the group of advanced-age women than in the groups of PCOS and non-PCOS women. Moreover, a significant positive correlation between FF-cf-mtDNA and the number of mature (MII) oocytes was observed. Collectively, the data show that the relative ratio of cf- mtDNA to cf-nDNA content in human FF can be an effective predictor for assessing the corresponding oocyte's age-related performance in IVF.

Elevated cell-free mitochondria DNA level of patients with premature ovarian insufficiency

BACKGROUND

Premature ovarian insufficiency (POI) patients present with a chronic inflammatory state. Cell-free mitochondria DNA (cf-mtDNA) has been explored as a reliable biomarker for estimating the inflammation-related disorders, however, the cf-mtDNA levels in POI patients have never been measured. Therefore, in the presenting study, we aimed to evaluate the levels of cf-mtDNA in plasma and follicular fluid (FF) of POI patients and to determine a potential role of cf-mtDNA in predicting the disease progress and pregnancy outcomes.

METHODS

We collected plasma and FF samples from POI patients, biochemical POI (bPOI) patients and control women. Quantitative real-time PCR was used to measure the ratio of mitochondrial genome to nuclear genome of cf-DNAs extracted from the plasma and FF samples.

RESULTS

The plasma cf-mtDNA levels, including COX3, CYB, ND1 and mtDNA79, were significantly higher in overt POI patients than those in bPOI patients or control women. The plasma cf-mtDNA levels were weakly correlated with ovarian reserve, and could not be improved by regular hormone replacement therapy. The levels of cf-mtDNA in FF, rather than those in plasma, exhibited the potential to predict the pregnancy outcomes, although they were comparable among overt POI, bPOI and control groups.

CONCLUSIONS

The increased plasma cf-mtDNA levels in overt POI patients indicated its role in the progress of POI and the FF cf-mtDNA content may hold the value in predicting pregnancy outcomes of POI patients.

hsa-miR-320a-3p and hsa-miR-483-5p levels in human granulosa cells: promising bio-markers of live birth after IVF/ICSI

BACKGROUND

MicroRNAs (miRNAs) are considered potential biomarkers for various diseases. This study investigated whether hsa-miR-320a-3p and hsa-miR-483-5p levels in human ovarian granulosa cells derived from follicular fluids are associated with embryo developmental competence.

METHODS

We collected 195 granulosa cells samples and analyzed the treatment outcomes in patients undergoing in vitro fertilization (n = 147) or intracytoplasmic sperm injection (n = 48) cycles. The hsa-miR-320a-3p and hsa-miR-483-5p levels in granulosa cells were measured using quantitative reverse transcription-polymerase chain reaction.

RESULTS

Patients were subdivided into four groups according to the granulosa cells hsa-miR-320a-3p and hsa-miR-483-5p levels quartiles (Q1-Q4). Embryo developmental competence was compared using the chi-square test. Patients in Q3 were less likely to achieve a normal fertilization rate for in vitro fertilization and blastocyst formation than those in Q1 as they expressed high levels of hsa-miR-320a-3p and hsa-miR-483-5p (P < 0.05). Patients in Q3 and Q4 were less likely to achieve a good-quality embryo as they expressed high levels of hsa-miR-483-5p and hsa-miR-320a-3p (P < 0.05). The hsa-miR-320a-3p and hsa-miR-483-5p levels were not associated with clinical pregnancy. However, multiple regression analysis indicated that in Q3 and Q4 intervals had experienced a decreased chance of live birth due to high expression levels of hsa-miR-320a-3p and hsa-miR-483-5p levels. The relative hsa-miR-320a-3p expression levels in granulosa cells were weakly and positively correlated with the patient age (P = 0.0033). Moreover, both the basal follicle stimulating hormone (P = 0.0003) and ovarian stimulation protocols (P = 0.006 and P = 0.004) significantly and positively affected hsa-miR-320a-3p levels. The days of stimulation was negatively correlated with the relative hsa-miR-320a-3p expression level (P = 0.047).

CONCLUSIONS

The hsa-miR-320a-3p and hsa-miR-483-5p levels in human granulosa cells negatively correlated with the good-quality embryo rate and live birth, indicating that hsa-miR-320a-3p and hsa-miR-483-5p can be used as potential negative indicators to predict good-quality embryos and live births.

Age-associated changes in cumulus cells and follicular fluid: the local oocyte microenvironment as a determinant of gamete quality

The ovary is the first organ to age in humans with functional decline evident already in women in their early 30s. Reproductive aging is characterized by a decrease in oocyte quantity and quality, which is associated with an increase in infertility, spontaneous abortions, and birth defects. Reproductive aging also has implications for overall health due to decreased endocrinological output. Understanding the mechanisms underlying reproductive aging has significant societal implications as women globally are delaying childbearing and medical interventions have greatly increased the interval between menopause and total lifespan. Age-related changes inherent to the female gamete are well-characterized and include defects in chromosome and mitochondria structure, function, and regulation. More recently, it has been appreciated that the extra-follicular ovarian environment may have important direct or indirect impacts on the developing gamete, and age-dependent changes include increased fibrosis, inflammation, stiffness, and oxidative damage. The cumulus cells and follicular fluid that directly surround the oocyte during its final growth phase within the antral follicle represent additional critical local microenvironments. Here we systematically review the literature and evaluate the studies that investigated the age-related changes in cumulus cells and follicular fluid. Our findings demonstrate unique genetic, epigenetic, transcriptomic, and proteomic changes with associated metabolomic alterations, redox status imbalance, and increased apoptosis in the local oocyte microenvironment. We propose a model of how these changes interact, which may explain the rapid decline in gamete quality with age. We also review the limitations of published studies and highlight future research frontiers.

The integrity of cfDNA in follicular fluid and spent medium from embryo culture is associated with embryo grade in patients undergoing in vitro fertilization

PURPOSE

This study was conducted to verify if the cfDNA integrity (cfDI) in follicular fluid and subsequent spent embryo medium (SEM) could serve as potential non-invasive biomarker for high-grade embryo selection during IVF/ICSI.

METHODS

Thirty-two follicular fluids, 32 subsequent corresponding cleavage embryo SEM, and 23 subsequent blastocyst SEM were collected from 11 patients undergoing IVF/ICSI. CfDI was measured by ALU gene amplicons with different sizes by qPCR, as the ratio of long to short fragments.

RESULTS

CfDI in follicular fluid corresponding to subsequent high-grade cleavage embryos and blastocysts was significantly lower than that related to low-grade embryos (p = 0.018). Conversely, cfDI in SEM was significantly and positively correlated with high-grade embryos at both stages (p = 0.009). ROC curves of the analysis of cfDI in follicular fluid showed great potential in predicting subsequent embryogenesis and embryo grade (AUC > 0.927). Regardless of the cleavage embryo grade by morphology, cfDI in day 3 SEM could predict if the cleavage embryo could develop to a high-grade blastocyst (AUC = 0.820). A concordant shift pattern of cfDI from follicular fluid to subsequent day 3 SEM and day 5 SEM was found in 81.82% participants featured by various clinical characteristics.

CONCLUSION

CfDI in follicular fluid and SEM was significantly correlated with embryogenesis and embryo grade and could serve as a potential non-invasive biomarker in high-grade embryo selection. Direct qPCR was proved as a labor-saving and sensitive method for the analysis of cfDI in low volume of SEM.

The association between the levels of anti-Müllerian hormone (AMH) and dietary intake in Iranian women

PURPOSE

This paper aimed to assess the association between AMH with dietary intake of adult women referred to the infertility clinic of Al-Zahra Hospital in Rasht, Iran.

METHODS

This cross-sectional study was performed on 234 adult women referred to the infertility clinic of Al-Zahra Hospital, Rasht, Iran. The participants were categorized into two groups based on their AMH levels. Participants' data on lifestyle and anthropometry as well as blood samples were collected. Dietary intakes were assessed by a validated food frequency questionnaire (FFQ).

RESULTS

Serum AMH concentration was negatively associated with the intake of fast foods (P = 0.002) and saturated fats (P = 0.040). These associations remained significant after adjustments for age, rural or urban location, and education. Additional adjustments for body mass index (BMI) and physical activity did not change the results. The results remained significant after further adjustments for menstrual age, menstrual pattern, and oral contraceptive pills.

CONCLUSION

Fast foods and saturated fats were significantly associated with lower AMH concentrations and modifying the amount of these dietary components may be an important strategy for increasing the reservation of ovaries in women. Future longitudinal studies are warranted to confirm these findings and to identify the underlying mechanisms.

Trophectoderm Mitochondrial DNA Content Associated with Embryo Quality and Day-5 Euploid Blastocyst Transfer Outcomes

Mitochondria play a critical role in cell function and embryo development. Recently, increasing studies have investigated whether mitochondrial DNA (mtDNA) can be used as a predictive biomarker of embryo implantation. However, the results of its effect on implantation are still controversial. To further understand the clinical application value of mtDNA content for reproductive potential, we analyzed the influence of relative mtDNA quantity on embryo quality and transfer outcomes based on the results of second-generation sequencing of preimplantation genetic testing patients in our center. Biopsied trophectoderm (TE) from aneuploid blastocysts contained much larger amounts of mtDNA than those from euploid blastocysts (p < 0.000). In an analysis of only euploid blastocysts (n = 769), female age had no effect on mtDNA content (p = 0.216). TE cells biopsied on day 5 (n = 355) contained significantly higher amounts of mtDNA compared to those biopsied on day 6 (n = 388) or day 7 (n = 26) (p < 0.000). Higher quality trophoblast was associated with lower mtDNA content (p = 0.026), but quality of inner cell mass was not correlated with quantity of mtDNA (p = 0.112). For transferred embryos, the biopsied date and mtDNA content were significantly associated with embryo implantation and live birth outcomes. Day-5 euploid blastocysts with lower quantities of mtDNA exhibited higher implantation rate and live birth rate. However, our data indicated that mtDNA content may not be considered an independent predictive marker, it may be a useful reference for the selection of day-5 transferred euploid blastocysts.

Cell-free mtDNA level and its biomarker potency for ART outcome are different in follicular fluid of PCOS and non-PCOS women

INTRODUCTION

Lack of reliable biomarkers for estimating the outcome is one of the current gaps in ART. In this study, we assessed whether cell-free mitochondrial DNA within the follicular fluid (FF cf-mtDNA) of PCOS patients has biomarker applicability or not. Furthermore, probable involved mechanisms in the FF cf-mtDNA pathway were evaluated.

METHODS

The level of FF cf-mtDNA was compared between 50 PCOS patients and 50 women without any certain reproductive disorder, and analyzed for correlations with ART outcome. The associations between levels of FF cf-mtDNA and TFAM, POLG, and RNase H1 genes expression in mural granulosa cells (MGCs), as well as IL-6, and TNFα in follicular fluid (FF) were assessed.

RESULTS

We identified that FF cf-mtDNA level was significantly lower in PCOS women and was accompanied by a reduction in the expression of mtDNA biogenesis genes in MGCs of the patients. Although a significant association between FF cf-mtDNA level and ART outcome was observed in the control group, no correlation could be proved in the PCOS group. Moreover, the expression level of TFAM was negatively associated, while amounts of IL-6 and TNFα were positively correlated with FF cf-mtDNA level in both groups.

CONCLUSION

PCOS patients present a lower FF cf-mtDNA level in comparison with non-PCOS women. FF cf-mtDNA has biomarker applicability for ART outcome in women without any certain reproductive disorder, but not for those with PCOS. It seems that mtDNA packaging dysfunction results in elevated FF cf-mtDNA, and subsequent effects are triggered by increasing the inflammatory cytokines.

Cell-free DNA discoveries in human reproductive medicine: providing a new tool for biomarker and genetic assays in ART

Cell-free DNAs (cfDNAs) are fragmented forms of DNA that are released into extracellular environments. Analyzing them, regarding either concentration or genetic/epigenetic status can provide helpful information about disorders, response to treatments, estimation of success rates, etc. Moreover, since they are presented in body fluids, evaluation of the aforementioned items would be achieved by less/non-invasive methods. In human reproduction field, it is required to have biomarkers for prediction of assisted reproduction techniques (ART) outcome, as well as some non-invasive procedures for genetic/epigenetic assessments. cfDNA is an appropriate candidate for providing the both approaches in ART. Recently, scientists attempted to investigate its application in distinct fields of reproductive medicine that resulted in discovering its applicability for biomarker and genetic/epigenetic analyses. However, due to some limitations, it has not reached to clinical administration yet. In this article, we have reviewed the current reported data with respect to advantages and limitations of cfDNA utilization in three fields of ART, reproduction of male and female, as well as in vitro developed embryos.

Cell-free mitochondrial DNA increases granulosa cell apoptosis and reduces aged oocyte blastocyst development in the mouse

Cell-free mitochondrial DNA (cf-mtDNA) released into the extracellular environment can cause cellular inflammatory responses and damage. Here, we investigated the effects of cf-mtDNA on mouse ovarian granulosa cell function and on the developmental competence of oocytes matured in vitro. Granulosa cells in the cf-mtDNA treatment group had a lower ATP content (P < 0.05), a higher apoptotic cell percentage (P < 0.01), and higher mRNA and protein levels of apoptosis-related factors than the control group (P < 0.01). TLR9, NF-кB p65 and MAPK p38 expression levels in granulosa cells were significantly increased in the cf-mtDNA treatment group (P < 0.05). The blastocyst formation rate of aged mice oocytes matured in vitro decreased significantly (P < 0.05) when cf-mtDNA was added to the media, compared with the control. However, the oocytes from young mice were not affected. Our results suggest that cf-mtDNA may impair granulosa cell function and induce granulosa cell apoptosis, subsequently decreasing blastocyst development in aged oocytes. This role of cf-mtDNA may be associated with the binding to TLR9 and the activation of NF-кB p65 and MAPK p38 signaling pathways.

Resolvin E1 in Follicular Fluid Acts as a Potential Biomarker and Improves Oocyte Developmental Competence by Optimizing Cumulus Cells

Metabolic profile of follicular fluid (FF) has been investigated to look for biomarkers for oocyte quality. Resolvin E1 (RvE1), a potent pro-resolving mediator, was reported to have protective action in cell function. The study aimed to examine the predictive value of RvE1 for oocyte quality and to explore the cellular mechanism of RvE1 in improving oocyte competence. Metabolic profiles of 80 FF samples showed a higher level of RvE1 in group A (blastocysts scored ≥ B3BC and B3CB according to Gardner's blastocyst scoring system, N = 36) than that of group B (blastocysts scored < B3BC and B3CB, N = 44, P = 0.0018). The receiver operating characteristic (ROC) curve analysis showed that RvE1 level in FF below 8.96 pg/ml (AUC:0.75; 95%CI: 0.64-0.86; P = 0.00012) could predict poor oocyte quality with specificity of 97.22%, suggesting RvE1 as a potential biomarker to exclude inferior oocytes. Besides, the level of RvE1 was found to be significantly lower in FF than in serum (57.49 to 17.62 pg/ml; P=.0037) and was gradually accumulated in the culture medium of cumulus cells (CCs) during cell culture, which indicated that RvE1 came from both blood exudates and local secretion. The in vitro experiment revealed thecellular mechanism of RvE1 in improvingoocyte qualityby decreasing the cumulus cellapoptotic rate and increasing cell viability and proliferation. It is the first time thatthe role of RvE1 in reproduction is explored. In conclusion, RvE1 is valuable as a potential exclusive biomarker for oocyte selection andplays a role in improving oocyte quality.

Cell-free DNA content in follicular fluid: A marker for the developmental ability of porcine oocytes

PURPOSE

The present study examined the relationships among the amount of cell-free-DNA (cfDNA) in porcine follicular fluid (FF), the developmental ability of enclosed oocytes, and characteristics of granulosa cells and examined the effect of cfDNA content in maturation medium on the developmental ability of the oocytes.

METHODS

Oocytes and FF were collected from individual gilts, and the gilts were rated based on the ability of their oocytes to develop to the blastocyst stage and the amount of cfDNA in the FF. The copy numbers of mitochondrial DNA (Mt-DNA) and nuclear DNA (N-DNA) were measured by real-time PCR and the DNA sequence. FF or cfDNA was added to the maturation medium, and the developmental ability of the oocytes was examined.

RESULTS

The amount of cfDNA was associated with apoptosis of the granulosa cells, and high-cfDNA content in FF was associated with low developmental ability of oocytes. Supplementation of the maturation medium with FF containing high cf-Mt-DNA or with DNA extracted from the FF did not affect oocyte developmental competence.

CONCLUSIONS

Cell-free DNA content in FF is a marker for oocyte competence, but cfDNA in the oocyte maturation environment did not affect oocyte developmental ability.