Human embryos in a dish – modeling early embryonic development with pluripotent stem cells

Stem cell-based embryo models present new opportunities to study early embryonic development. In a recent study, Kagawa et al. identified an approach to create human pluripotent stem cell-based blastoids that resemble the human blastocysts. These blastoids efficiently generated analogs of the EPI, TE, PrE lineages with transcriptomes highly similar to those found in vivo. Furthermore, the formation of these lineages followed the same sequence and pace of blastocyst development, and was also dependent on the same pathways required for lineage specification. Finally, the blastoids were capable of attaching to stimulated endometrial cells to mimic the process of implantation. While more comprehensive analysis is needed to confirm its validity and usefulness, this new blastoid system presents the latest development in the attempt to model early human embryogenesis in vitro.

Smooth Endoplasmic Reticulum Clusters in Oocytes From Patients Who Received Intracytoplasmic Sperm Injections Negatively Affect Blastocyst Quality and Speed of Blastocyst Development

Findings regarding the relationship between smooth endoplasmic reticulum clusters (SERCs) in oocytes and blastocyst development have been conflicting. In this study, the effects of SERCs on blastocyst quality and the speed of blastocyst development were evaluated. Patients who received intracytoplasmic sperm injections (ICSI) at our reproductive center from 2016 to 2020 were retrospectively analyzed. SERC (+) oocytes (n = 217) and SERC (–) oocytes (n = 822), as well as SERC (+) cycles (n = 146) and SERC (–) cycles (n = 1,951) were compared. There was no significant difference in embryological, clinical, and neonatal outcomes between the SERC (+) and SERC (–) cycles. The fertilization rate (73.9%), good quality blastocyst rate (26.7%) and the speed of blastocyst development (44.4%) were significantly lower (P < 0.05) in SERC (+) oocytes than in unaffected counterparts (86.2%, 44.1% and 63.4%, respectively). Furthermore, the proportion of blastocysts with trophectoderm (TE) grade C was significantly higher in the SERC (+) oocyte group than in the SERC (–) oocyte group (73.3 vs. 55.9%, P < 0.05). After adjusting for age, years of infertility, endometriosis, stimulation protocols (GnRHa), and male infertility, multiple logistic regression analysis revealed that the presence of SERCs in the oocytes significantly affected the speed of blastocyst development (odds ratio, 2.812; 95% CI, 1.257–6.292; P = 0.012). These findings suggest that the presence of SERCs in oocytes may negatively affect blastocyst quality and the speed of blastocyst development.

Biology of Perseverative Negative Thinking: The Role of Timing and Folate Intake

Past-oriented rumination and future-oriented worry are two aspects of perseverative negative thinking related to the neuroticism endophenotype and associated with depression and anxiety. Our present aim was to investigate the genomic background of these two aspects of perseverative negative thinking within separate groups of individuals with suboptimal versus optimal folate intake. We conducted a genome-wide association study in the UK Biobank database (n = 72,621) on the “rumination” and “worry” items of the Eysenck Personality Inventory Neuroticism scale in these separate groups. Optimal folate intake was related to lower worry, but unrelated to rumination. In contrast, genetic associations for worry did not implicate specific biological processes, while past-oriented rumination had a more specific genetic background, emphasizing its endophenotypic nature. Furthermore, biological pathways leading to rumination appeared to differ according to folate intake: purinergic signaling and circadian regulator gene ARNTL emerged in the whole sample, blastocyst development, DNA replication, and C-C chemokines in the suboptimal folate group, and prostaglandin response and K+ channel subunit gene KCNH3 in the optimal folate group. Our results point to possible benefits of folate in anxiety disorders, and to the importance of simultaneously taking into account genetic and environmental factors to determine personalized intervention in polygenic and multifactorial disorders.

Increased Systemic Antioxidant Power Ameliorates the Aging-Related Reduction in Oocyte Competence in Mice

Ovarian aging is associated with elevated oxidative stress and diminished oocyte developmental competence. We aimed to determine the impact of systemic antioxidant treatment in aged mice. Female outbred CF-1 mice were aged for 9 months prior to an 8-week 45 mg Euterpe oleracea (açaí) daily supplement. The açaí treatment induced a threefold increase in serum antioxidant power (FRAP) compared to both young and aged mice (p < 0.0001). Compared to young mice, aged mice had fewer oocytes and reduced blastocyst development (p < 0.0001); açaí did not affect the oocyte numbers, but improved blastocyst formation (p < 0.05). Additionally, açaí alleviated the aging-related decrease in implantation potential (p < 0.01). The aged mice showed evidence of elevated ovarian ER stress (increased whole-ovary PDIA4 expression, granulosa cell and oocyte GRP78 expression, and oocyte PDIA4 protein), reduced oocyte mitochondrial quality (higher PRKN activation and mitochondrial DNA oxidative damage), and dysregulated uterine glandular epithelium. Antioxidant intervention was sufficient to lessen these effects of ovarian aging, likely in part by the upregulation of NRF2. We conclude that açaí treatment is a promising strategy to improve ER and mitochondrial function in the ovaries, thereby ameliorating the decreased oocyte competence that occurs with ovarian aging.

Clinical Relevance of Secreted Small Noncoding RNAs in an Embryo Implantation Potential Prediction at Morula and Blastocyst Development Stages

Despite the improvements in biotechnological approaches and the selection of controlled ovarian hyperstimulation protocols, the resulting pregnancy rate from in vitro fertilization (IVF) protocols still does not exceed 30–40%. In this connection, there is an acute question of the development of a non-invasive, sensitive, and specific method for assessing the implantation potential of an embryo. A total of 110 subfertile couples were included in the study to undergo the IVF/ICSI program. Obtained embryos for transfer into the uterine cavity of patient cohort 1 (n = 60) and cohort 2 (n = 50) were excellent/good-quality blastocysts, and small noncoding RNA (sncRNA) content in the corresponding spent culture medium samples at the morula stage (n = 43) or at the blastocyst stage (n = 31) was analyzed by deep sequencing followed by qRT-PCR in real time. Two logistic regression models were developed to predict the implantation potential of the embryo with 100% sensitivity and 100% specificity: model 1 at the morula stage, using various combinations of hsa_piR_022258, hsa-let-7i-5p, hsa_piR_000765, hsa_piR_015249, hsa_piR_019122, and hsa_piR_008112, and model 2 at the blastocyst stage, using various combinations of hsa_piR_020497, hsa_piR_008113, hsa-miR-381-3p, hsa_piR_022258, and hsa-let-7a-5p. Protein products of sncRNA potential target genes participate in the selective turnover of proteins through the ubiquitination system and in the organization of the various cell cytoskeleton and nucleoskeleton structures, regulating the activity of the Hippo signaling pathway, which determines the fate specification of the blastomers.

Grape Seed Proanthocyanidin Ameliorates FB1-Induced Meiotic Defects in Porcine Oocytes

Fumonisin B1 (FB1), as the most prevalent and toxic fumonisin, poses a health threat to humans and animals. The cytotoxicity of FB1 is closely related to oxidative stress and apoptosis. The purpose of this study is to explore whether Grape seed proanthocyanidin (GSP), a natural antioxidant, could alleviate the meiotic maturation defects of oocytes caused by FB1 exposure. Porcine cumulus oocyte complexes (COCs) were treated with 30 μM FB1 alone or cotreated with 100, 200 and 300 μM GSP during in vitro maturation for 44 h. The results show that 200 μM GSP cotreatment observably ameliorated the toxic effects of FB1 exposure, showing to be promoting first polar body extrusion and improving the subsequent cleavage rate and blastocyst development rate. Moreover, 200 μM GSP cotreatment restored cell cycle progression, reduced the proportion of aberrant spindles, improved actin distribution and protected mitochondrial function in FB1-exposed oocytes. Furthermore, reactive oxygen species (ROS) generation was significantly decreased and the mRNA levels of CAT, SOD2 and GSH-PX were obviously increased in the 200 μM GSP cotreatment group. Notably, the incidence of early apoptosis and autophagy level were also significantly decreased after GSP cotreatment and the mRNA expression levels of BAX, CASPASE3, LC3 and ATG5 were markedly decreased, whereas BCL2 and mTOR were observably increased in the oocytes after GSP cotreatment. Together, these results indicate that GSP could exert significant preventive effects on FB1-induced oocyte defects by ameliorating oxidative stress through repairing mitochondrial dysfunction.

Non-invasive Metabolomic Profiling of Embryo Culture Medium Using Raman Spectroscopy With Deep Learning Model Predicts the Blastocyst Development Potential of Embryos

Purpose: This study aimed to establish a non-invasive predicting model via Raman spectroscopy for evaluating the blastocyst development potential of day 3 high-quality cleavage stage embryos.Methods: Raman spectroscopy was used to detect the metabolic spectrum of spent day 3 (D3) embryo culture medium, and a classification model based on deep learning was established to differentiate between embryos that could develop into blastocysts (blastula) and that could not (non-blastula). The full-spectrum data for 80 blastula and 48 non-blastula samples with known blastocyst development potential from 34 patients were collected for this study.Results: The accuracy of the predicting method was 73.53% and the main different Raman shifts between blastula and non-blastula groups were 863.5, 959.5, 1,008, 1,104, 1,200, 1,360, 1,408, and 1,632 cm–1 from 80 blastula and 48 non-blastula samples by the linear discriminant method.Conclusion: This study demonstrated that the developing potential of D3 cleavage stage embryos to the blastocyst stage could be predicted with spent D3 embryo culture medium using Raman spectroscopy with deep learning classification models, and the overall accuracy reached at 73.53%. In the Raman spectroscopy, ribose vibration specific to RNA were found, indicating that the difference between the blastula and non-blastula samples could be due to materials that have similar structure with RNA. This result could be used as a guide for biomarker development of embryo quality assessment in the future.

Detection of Brucella abortus during in vitro bovine embryo production

The in vitro embryo production (IVP) technology has emerged as a potential biotechnological approach to multiply genetically high yielding dairy cows. Its commercial application is increasing in many developed and developing countries over the years. Bangladesh livestock Research Institute (BLRI) adopted in vitro embryo production protocol from bovine ovaries of slaughterhouse. However, the risks of transmission of contagious diseases like Brucella abortus with embryos are not evaluated so far. Considering these facts, the present experiments were conducted to evaluate the efficiency of in vitro embryo production protocol with slaughterhouse ovaries as well as risk of contamination of produced embryos with Brucella abortus. To identify sources of contamination of embryos with Brucella abortus (if any), the laboratory water, different media used in the IVP process, semen, and follicular fluids were evaluated for confirmation of the organisms. In addition, vaginal swabs were collected from 2 buffaloes aborted due to suspected Brucella abortus infection. Molecular test were used to detect Brucella abortus contamination. Brucella abortus specific PCR product was not detected on agarose gel electrophoresis. The efficiency of IVP measured by cleavage and blastocyst development rates were 75.5±2.7% and 16.6±3.9%, respectively. The present study inferred that the in vitro produce embryos are free from Brucella abortus infection. Bang. J. Livs. Res. Vol. 27 (1&2), 2020: P. 105-112