Effect of Cerium Oxide Nanoparticles on the Expression of Developmental and Apoptosis Genes of Testicular Tissue in 6-Day-Old NMRI Mice Fetuses.

Cerium oxide (CeO2) has potential applications in medicine and various consumer products. This study investigated the effect of CeO2 on the expression of genes associated with apoptosis and testicular development in mouse embryos. The experimental groups of pregnant mice were injected intraperitoneally with CeO2 at a concentration of 10 mg/kg on days 7 and 14 of pregnancy. Six days after birth, the testicles of neonatal male mice were collected for mRNA expression determination using real-time PCR, protein expression analysis by immunohistochemistry, and apoptotic cell population determination using the TUNEL assay. The results showed that the mRNA expression of the Bax, Caspase-3, and Gsk3-ß genes, unlike the Bcl2 gene, decreased significantly in the experimental group compared to the control group. The expression ratio of Bax/Bcl2 in the experimental group was lower than in the control group. A similar trend was observed in the population of apoptotic cells. In the experimental group, the expression levels of, Gata4, Sox8, and Rad54 at both the mRNA and protein levels increased significantly compared to the control group. Based on the results of this study, CeO2 at a concentration of 10 mg/kg, in addition to producing anti-apoptotic effects on the testicular cells of neonatal mice, can increase the expression of genes involved in testicular development and performance. The current experimental study proved the protective effects of 10 mg/kg CeO2 in developmental and apoptosis genes of testicular tissue in 6-day-old NMRI mice fetuses; however, more experiments are required to evaluate the possible side effects and interactions.

Effect of cyanocobalamin on oocyte maturation, in vitro fertilization, and embryo development in mice.

The aim of this study was to investigate the effect of cyanocobalamin supplementation on in vitro maturation (IVM), in vitro fertilization (IVF), and subsequent embryonic development competence to the blastocyst stage, and in vitro development of mouse 2-cell embryos. Cumulus cells were prepared from mouse cumulus-oocyte complexes (COCs) and incubated for 24 h in an in vitro culture (IVC) medium that contained different concentrations of cyanocobalamin (100, 200, 300 or 500 pM). We collected 2-cell embryos from superovulated NMRI mice and cultured them in the same concentrations of cyanocobalamin (100, 200, 300 or 500 pM). After 42 h of IVM, we observed significantly increased oocyte maturation in the 200 pM cyanocobalamin-treated group compared with the control group (P < 0.0001). Mature oocytes cultured in 200 pM cyanocobalamin were fertilized and cultured in IVC medium with cyanocobalamin (100, 200, 300 or 500 pM) during early embryogenesis. The matured oocytes that were cultured in 200 pM cyanocobalamin had significantly higher 2-cell development rates compared with the control oocytes (P < 0.01). Embryos obtained from in vitro mature oocytes and in vivo fertilized oocytes that were cultured in 200 pM cyanocobalamin had significantly greater frequencies of development to the blastocyst stage and a significant reduction in 2-cell blocked and degenerated embryos compared with the control embryos (P < 0.0001). Embryos derived from oocytes fertilized in vivo with 200 pM cyanocobalamin had a higher percentage of blastocyst embryos compared with those derived from matured oocytes cultured in vitro (P < 0.0001). These finding demonstrated that the effects of cyanocobalamin on oocyte maturation, fertilization, and embryo development in mice depend on the concentration used in IVC medium.