Background: Unique properties of graphene and its derivatives make them attractive in the field of nanomedicine. However, the mass application of graphene might lead to side effects, which has not been properly addressed in previous studies, especially with regard to its effect on the cell cycle. Methods: The effect of two concentrations (100 and 200 μg/mL) of nano-and microsized graphene oxide (nGO and mGO) on apoptosis, cell cycle, and ROS generation was studied. The effect of both sizes on viability and genotoxicity of the embryonic fibroblast cell cycle was evaluated. MTT and flow cytometry were applied to evaluate the effects of graphene oxide (GO) nanosheets on viability of cells. Apoptosis and cell cycle were analyzed by flow cytometry. Results: The results of this study showed that GO disturbed the cell cycle and nGO impaired cell viability by inducing cell apoptosis. Interestingly, both nGO and mGO blocked the cell cycle in the S phase, which is a critical phase of the cell cycle. Upregulation of TP53-gene transcripts was also detected in both nGO-and mGO-treated cells compared to the control, especially at 200 μg/mL. DNA content of the treated cells increased; however, because of DNA degradation, its quality was decreased. Conclusion: In conclusion, graphene oxide at both nano-and micro-scale damages cell physiology and increases cell population in the S phase of the cell cycle.

The fate of mesenchymal stem cells is greatly influenced by the surface chemistry of silica nanoparticles in 3D hydrogel-based culture systems,

Vitrification negatively affects the mitochondrial membrane potential (ΔΨm) in oocytes while also leading to increased reactive oxygen species (ROS), ATP depletion and induction of apoptosis in oocytes. Mitoquinone (MitoQ) is an antioxidant that protects mitochondrial membrane integrity from ROS. This study examined the effect of adding MitoQ to vitrification medium on mitochondrial function and embryo development in vitrified oocytes. Metaphase II (MII) stage oocytes were collected from NMRI mouse ovaries and preincubated for 20 min in a medium containing 0.02 µM of MitoQ. Next, oocytes were vitrified in medium supplemented with 0.02 μM of MitoQ (treatment group). The control group was processed in the same way but without exposure to MitoQ. After warming, oocyte survival rate, ΔΨm, cytoplasmic ROS and glutathione (GSH) levels and gene expression levels (Bcl2, BAX, and caspase3) were measured. In addition, the vitrified oocytes were fertilized in-vitro to assess developmental competence. The results showed that MitoQ improved survival and ΔΨm in treated vitrified oocytes. Treated oocytes showed lower ROS levels and higher GSH levels than did the control group. Furthermore, mRNA expression of the Bax/Bcl2 ratio and caspase3 were significantly lower in treated oocytes. These findings indicate that medium supplementation with 0.02 μM of MitoQ during vitrification can improve oocyte survival and developmental competency in mouse oocytes.

Abstract. CTCF is a highly conserved protein among eukaryotes and it is involved in many of regulatory functions including, transcriptional repression and activation, chromatin insulation, imprinting, X chromosome inactivation, higher-order chromatin organization, and alternative splicing. Studies performed on mouse embryos indicate that CTCF can be a maternal-effect gene, and is essential for normal development of embryos. CTCF can be used as a molecular effector for the proper epigenetic establishment of embryonic development. The aim of this study was to determine changes in transcript levels of the CTCF gene in bovine preimplantation embryos. RNA was extracted from immature and mature oocytes and embryos at various developmental stages (two-cell, four-cell, eight-cell, and blastocysts). Results showed that the amounts of CTCF transcripts decreased in mature oocyte in comparison with immature oocytes, but this change was not significant. In addition, the amount of CTCF transcript in embryos at two-cell, four-cell, eight-cell, and blastocyst stages significantly increased in comparison with immature oocytes. These data show that CTCF expression in bovine embryo begins at minor embryonic genome activation.

Maternal effect genes have highly impressive effects on pre-implantation development. Filia/Ecat1/Khdc3l is a maternal effect gene found in mouse oocytes and embryos, loss of which causes a 50% decrease in fertility. In the present study, we investigated Filia mRNA expression in bovine oviduct, 30- to 40-day fetus, liver, heart, lung, and oocytes (as a positive control), by RT-PCR and detected it only in oocytes. A 443 bp fragment was amplified only in oocytes and was sequenced as a part of bovine predicted Filia mRNA. We analyzed bovine and ovine Filia N-terminal peptide sequence in PHYRE2, and a KH domain was predicted. Protein alignment using ClustalW indicated a highly identical N-terminal extention between the 2 species. Immunohistochemical analysis using anti-bovine Filia antibody showed the expression of Filia protein in the zone surrounding the nuclear membrane, and in the subcortex of ovine oocytes of primary and antral follicles. However, in the bovine, Filia has been found through the oocyte cytoplasm of antral follicles, and here it is further confirmed in the primary follicles. Our data suggests a difference in Filia expression pattern between cow and sheep, although the sequence is highly conserved.