Ageing populations, mass \"baby-free\" policies and children born to mothers at the age at which they are biologically expected to become grandmothers are growing problems in most developed societies. Therefore, any opportunity to improve the quality of infertility treatments seems important for the survival of societies. The possibility of indirectly studying the quality of developing oocytes by examining their follicular fluids (hFFs) offers new opportunities for progress in our understanding the processes of final oocyte maturation and, consequently, for predicting the quality of the resulting embryos and personalising their culture. Using mass spectrometry, we studied follicular fluids collected individually during in vitro fertilisation and compared their composition with the quality of the resulting embryos. We analysed 110 follicular fluids from 50 oocyte donors, from which we obtained 44 high-quality, 39 medium-quality, and 27 low-quality embryos. We identified 2182 proteins by Sequential Window Acquisition of all Theoretical Mass Spectra (SWATH-MS) using a TripleTOF 5600+ hybrid mass spectrometer, of which 484 were suitable for quantification. We were able to identify several proteins whose concentrations varied between the follicular fluids of different oocytes from the same patient and between patients. Among them, the most important appear to be immunoglobulin heavy constant alpha 1 (IgA1hc) and dickkopf-related protein 3. The first one is found at higher concentrations in hFFs from which oocytes develop into poor-quality embryos, the other one exhibits the opposite pattern. None of these have, so far, had any specific links to fertility disorders. In light of these findings, these proteins should be considered a primary target for research aimed at developing a diagnostic tool for oocyte quality control and pre-fertilisation screening. This is particularly important in cases where the fertilisation of each egg is not an option for ethical or other reasons, or in countries where it is prohibited by law.

Global warming poses significant challenges to the fertility of tropical dairy cattle. One promising approach to mitigate heat stress effects on reproductive function and reduce the carbon footprint is the use of integrated livestock-forest (ILF) systems. The aim of this study was to investigate the effects of two different systems, namely Full Sun (FS) and ILF, on maternal hyperthermia and oocyte quality of Holstein and Girolando heifers during the tropical summer season. The temperature-humidity index (THI) data revealed intense heat stress during the experiment. Both the system (P<0.01) and the breed (P<0.01) factors had a significant impact on vaginal temperature, being hyperthermia more pronounced in the FS system and in the Holstein breed. Over the five time points collected at a 33-day interval, we observed distinct patterns for ILF (P=0.65) and FS (P<0.001) systems, suggesting an adaptive response in animals kept in FS systems. Furthermore, oocyte quality assessment revealed an effect of the system for oocyte diameter (P<0.001) and levels of IGFBP2 (P<0.001), and caspase 3 levels showed a decrease in ILF compared to FS for both Holstein (P<0.001) and Girolando (P<0.001) breeds. Collectively, these parameters indicate that oocyte quality during the summer months was superior in animals maintained in the ILF system. In conclusion, the ILF system demonstrated promising results in attenuating maternal hyperthermia and mitigating its effects on oocyte quality. Additionally, our observations suggest that animals in the FS system may exhibit an adaptive response to heat stress.

BACKGROUND: Nanoplastics (NPs) are emerging pollutants that pose risks to living organisms. Recent findings have unveiled the reproductive harm caused by polystyrene nanoparticles (PS-NPs) in female animals, yet the intricate mechanism remains incompletely understood. Under this research, we investigated whether sustained exposure to PS-NPs at certain concentrations in vivo can enter oocytes through the zona pellucida or through other routes that affect female reproduction.
RESULTS: We show that PS-NPs disrupted ovarian functions and decreased oocyte quality, which may be a contributing factor to lower female fertility in mice. RNA sequencing of mouse ovaries illustrated that the PI3K-AKT signaling pathway emerged as the predominant environmental information processing pathway responding to PS-NPs. Western blotting results of ovaries in vivo and cells in vitro showed that PS-NPs deactivated PI3K-AKT signaling pathway by down-regulating the expression of PI3K and reducing AKT phosphorylation at the protein level, PI3K-AKT signaling pathway which was accompanied by the activation of autophagy and apoptosis and the disruption of steroidogenesis in granulosa cells. Since PS-NPs penetrate granulosa cells but not oocytes, we examined whether PS-NPs indirectly affect oocyte quality through granulosa cells using a granulosa cell-oocyte coculture system. Preincubation of granulosa cells with PS-NPs causes granulosa cell dysfunction, resulting in a decrease in the quality of the cocultured oocytes that can be reversed by the addition of 17β-estradiol.
CONCLUSIONS: This study provides findings on how PS-NPs impact ovarian function and include transcriptome sequencing analysis of ovarian tissue. The study demonstrates that PS-NPs impair oocyte quality by altering the functioning of ovarian granulosa cells. Therefore, it is necessary to focus on the research on the effects of PS-NPs on female reproduction and the related methods that may mitigate their toxicity.

Infertility affects approximately 15% of couples at child-bearing ages and assisted reproductive technologies (ART), especially in vitro fertilization and embryo transfer (IVF-ET), provided infertile patients with an effective solution. The current paradox is that multiple embryo transfer that may leads to severe obstetric and perinatal complications seems to be the most valid measure to secure high success rate in the majority of clinic centers. Therefore, to avoid multiple transfer of embryos, it is urgent to explore biomarkers for IVF prognosis to select high-quality oocytes and embryos. Follicular fluid (FF), a typical biofluid constituted of the plasma effusion and granulosa-cell secretion, provides essential intracellular substances for oocytes maturation and its variation in composition reflects oocyte developmental competence and embryo viability. With the advances in metabolomics methodology, metabolomics, as an accurate and sensitive analyzing method, has been utilized to explore predictors in FF for ART success. Although FF metabolomics has provided a great possibility for screening markers with diagnostic and predictive value, its effectiveness is still doubted by some researchers. This may be resulted from the ignorance of the impact of sterility causes on the FF metabolomic profiles and thus its predictive ability might not be rightly illustrated. Therefore, in this review, we categorically demonstrate the study of FF metabolomics according to specific infertility causes, expecting to reveal the predicting value of metabolomics for IVF outcomes.

Assisted reproduction technology (ART) procedures are often impacted by post-ovulatory aging (POA), which can lead to reduced fertilization rates and impaired embryo development. This study used RNA sequencing analysis and experimental validation to study the similarities and differences between in vivo- and vitro-matured porcine oocytes before and after POA. Differentially expressed genes (DEGs) between fresh in vivo-matured oocyte (F_vivo) and aged in vivo-matured oocyte (A_vivo) and DEGs between fresh in vitro-matured oocyte (F_vitro) and aged in vitro-matured oocyte (A_vitro) were intersected to explore the co-effects of POA. It was found that \"organelles\", especially \"mitochondria\", were significantly enriched Gene Ontology (GO) terms. The expression of genes related to the \"electron transport chain\" and \"cell redox homeostasis\" pathways related to mitochondrial function significantly showed low expression patterns in both A_vivo and A_vitro groups. Weighted correlation network analysis was carried out to explore gene expression modules specific to A_vivo. Trait-module association analysis showed that the red modules were most associated with in vivo aging. There are 959 genes in the red module, mainly enriched in \"RNA binding\", \"mRNA metabolic process\", etc., as well as in GO terms, and \"spliceosome\" and \"nucleotide excision repair\" pathways. DNAJC7, IK, and DDX18 were at the hub of the gene regulatory network. Subsequently, the functions of DDX18 and DNAJC7 were verified by knocking down their expression at the germinal vesicle (GV) and Metaphase II (MII) stages, respectively. Knockdown at the GV stage caused cell cycle disorders and increase the rate of abnormal spindle. Knockdown at the MII stage resulted in the inefficiency of the antioxidant melatonin, increasing the level of intracellular oxidative stress, and in mitochondrial dysfunction. In summary, POA affects the organelle function of oocytes. A_vivo oocytes have some unique gene expression patterns. These genes may be potential anti-aging targets. This study provides a better understanding of the detailed mechanism of POA and potential strategies for improving the success rates of assisted reproductive technologies in pigs and other mammalian species.

Pre-incubation of the cumulus-oocyte complex (COCs) may lead to better function of cumulus cells (CCs) and higher oocyte quality by changing the transcriptomic profile of CCs. 140 cumulus cell samples were isolated from 12 participants and divided into two groups based on pre-incubation time. In the T0 group, the COCs were immediately dissected to separate the CCs from around the oocytes. In the T2 group, CCs were prepared after 2 h of incubation. Then, the transcriptomic profile of the CCs of the non pre-incubation group was compared to the 2-h pre-incubation group. Confirmation of RNA sequencing results was done via qRT‑PCR. The CCs transcriptome analysis showed 17 genes were downregulated and 22 genes upregulated in the T2 group compared to the T0 group. Also, the pathways related to ATP production (oxidative phosphorylation, electron transport chain, and Mitochondrial complex I assembly model OXPHOS system), TNF-alpha signaling pathway, and glucocorticoid receptor pathway increased in the T2 group compared to the T0 group. Also, the TGF-β pathway was decreased in the T2 group compared to the T0 group. This study showed that 2 h pre-incubation leads to changes in important pathways in CCs, which positively affects oocyte quality.

OBJECTIVE: Age-related decline in the number of ovulations and ovum quality are major causes of female infertility, and stem cells have been reported to be effective in tissue regeneration. However, current therapeutic modalities are inadequate. This study investigated the effects of adipose-derived mesenchymal stem cells (ASCs) on ovarian functions in aged mice.
METHODS: Following the characterization of ASCs using flow cytometry, the effects of ASCs on the number of ovulations, fertilization rate, and blastocyst-formation rate were investigated. In addition, the number of ovarian follicles and serum anti-Müllerian hormone (AMH) levels were examined. ASCs marked with Kusabira Orange were used to examine the location after cell administration. The quality of ovulated oocytes was analyzed using next-generation RNA sequencing.
RESULTS: ASCs showed characteristics of mesenchymal stem cells and were distributed to various organs, including the ovarian stroma. The transplantation resulted in increased number of oocytes and ovulation in the ovaries and increased AMH values. Genetic analysis revealed improved oocyte quality and increased fertilization and blastocyst-formation rates.
CONCLUSIONS: ASC therapy may be effective in improving fertility in older women.

UNASSIGNED: This study aimed to compare the thiol/disulfide balance, myeloperoxidase, and ischemia-modified albumin levels in the follicular fluid (FF) of poor ovarian response (POR) and normal ovarian response (NOR) women who received intracytoplasmic sperm injection (ICSI).
UNASSIGNED: The study was performed between March 2021 and April 2022 at the Department of Obstetrics and Gynecology, Center for Reproductive Medicine, Ankara City Hospital. The study included 27 POR and 35 NOR women who underwent ICSI. FF was obtained after the controlled ovarian stimulation cycle. The FF thiol/disulfide balance was detected using spectrophotometric methods. A correlation analysis was conducted to determine whether these oxidative stress markers could contribute to predicting oocyte quality.
UNASSIGNED: Disulfide levels were significantly higher in the NOR group than in the POR group (p=0.014). The number of fertilized egg (2PN) oocytes was positively correlated with the total thiol level (r=0.258, p=0.046). The disulfide level was positively correlated with the anti-Müllerian hormone level (r=0.262, p=0.039) and the total number of retrieved oocytes (r=0.335, p=0.008).
UNASSIGNED: The disulfide levels differed significantly between the NOR and POR groups. The statistically significant differences of fewer metaphase II oocytes and lower percentage of good-quality embryos in the NOR group compared to the POR group might have resulted from the NOR group\'s elevated disulfide levels. The total thiol levels correlated with the total of 2PN oocytes. Future studies should examine the thiol/disulfide balance at assisted reproductive technology centers to predict which oocytes could be fertilized.

Cancer is a global public health issue and remains one of the leading causes of death in the United States (Siegel et al. CA Cancer J Clin. 72:7-33, 2022). It is estimated in the US in 2022, about 935,000 new cases of cancer will be diagnosed in women, and the probability of developing invasive cancer is 5.8% for females younger than 50 years old (Siegel et al. CA Cancer J Clin. 72:7-33, 2022). However, advances in screening programs, diagnostic methods, and therapeutic options have greatly increased the five-year survival rate in reproductive-age women with a variety of cancers. Given the clinical consequences of gonadotoxic cancer therapies, young, female cancer survivors may face compromised fertility, premature ovarian insufficiency, early-onset menopause, and endocrine dysregulation (Bedoschi et al. Future Oncol. 12:2333-44, 2016). Gonadotoxic side effects may include decreased oocyte quality within surviving follicles, loss of ovarian follicles, and impaired ovarian function. In reproductive-age women, oocyte quality is an important element for successful clinical pregnancies and healthy offspring as poor-quality oocytes may be a cause of infertility (McClam et al. Biol Reprod. 106:328-37, 2022; Marteil et al. Reprod Biol. 9:203-24, 2009; Krisher. J Anim Sci. 82: E14-E23, 2004). Thus, it is critical to determine the quantity and quality of surviving follicles in the ovary after cancer treatment and to assess oocyte quality within those surviving follicles as these are markers for determining the capacity for ovarian function restoration and future fertility, especially for young cancer survivors (Xu et al. Nat Med. 17:1562-3, 2011). The long-term effects of cancer therapeutics on oocyte quality are influenced by factors including, but not limited to, individual patient characteristics (e.g. age, health history, comorbidities, etc.), disease type, or treatment regimen (Marci et al. Reprod Biol Endocrinol. 16:1-112, 2018). These effects may translate clinically into an impaired production of viable oocytes and compromised fertility (Garutti et al. ESMO Open. 6:100276, 2021).

This systematic review and meta-analysis aimed to evaluate the impact of ovarian endometriomas (OMA) on indirect markers of oocyte quality in patients undergoing IVF, compared with women without anatomical or functional ovarian abnormalities. The search spanned original randomized controlled trials, case-control studies and cohort studies published in MEDLINE, the Cochrane Controlled Trials Register and the ClinicalTrials.gov database up to October 2023. Thirty-one studies were included in the meta-analysis, showing no significant differences in fertilization (OR 1.10, 95% CI 0.94-1.30), blastulation (OR 0.86, 95% CI 0.64-1.14) and cancellation (OR 1.06, 95% CI 0.78-1.44) rates. However, patients with OMA exhibited significantly lower numbers of total and mature (metaphase II) oocytes retrieved (mean difference -1.59, 95% CI -2.25 to -0.94; mean difference -1.86, 95% CI -2.46 to -1.26, respectively), and lower numbers of top-quality embryos (mean difference -0.49, 95% CI -0.92 to -0.06). The Ovarian Sensitivity Index was similar between the groups (mean difference -1.55, 95% CI -3.27 to 0.18). The lack of data published to date prevented meta-analysis on euploidy rate. In conclusion, although the presence of OMA could decrease the oocyte yield in patients undergoing IVF/intracytoplasmic sperm injection, it does not appear to have an adverse impact on oocyte quality.