In this study, we examined the effects of a two-step culture system, which involves the use of different culture media for early cleavage and later stage embryos, on the in vitro development of bovine embryos. We also investigated the effect of glucose, phosphate and citrate on the in vitro early developmental period of bovine embryos in a two-step culture system. Moreover, the supplementation of different protein sources (BSA-V, BSA-FAF and FBS) during IVC did not affect the frequency of blastocyst development. Using two-step culture, embryos were cultured in protein-free media for an initial 5 days. This was then followed by the same culture media or an FBS supplemented media. The developmental rates of blastocysts in the FBS containing group were significantly higher than in the replaced with no serum containing group. Embryos cultured in mSOF supplemented with 1.5 mM glucose plus 1.2 mM phosphate were significantly inhibited. The inhibition of developmental competence by glucose plus phosphate was consistent with the existence of 0.5 mM sodium citrate. This study indicates that a two-step culture system, which applies different conditions for early cleavage embryos, i.e., serum-free media, vs. later stage embryos, with serum containing media, may be effective for in vitro production systems. In addition, the developmental competence of bovine embryos was depressed in the presence of glucose plus phosphate as compared to either alone or the absence of both. Therefore, the avoidance of this negative effect should allow more optimal conditions to be developed for in vitro production.
Animals ; Blastocyst/drug effects/metabolism ; Cattle/*embryology ; Citric Acid/pharmacology ; Culture Media/*chemistry ; Culture Techniques/*methods ; Ectogenesis/drug effects ; Embryo/*drug effects/embryology/metabolism ; Embryonic and Fetal Development/drug effects ; *Energy Metabolism ; Female ; Fertilization in Vitro ; Glucose/pharmacology ; Male ; Phosphates/pharmacology ; Proteins/*pharmacology ; Zygote/drug effects/metabolism

To further test whether protein kinase A (PKA) can affect the mitotic cell cycle, one-cell stage mouse embryos at S phase (22 h after hCG injection) were incubated in M16 medium containing various concentrations of H-89, a PKA inhibitor. With increasing concentrations of H-89 (0-50 μmol/L), the G(2) phase of eggs was decreased and the cleavage rate was accelerated. A concentration of 40 μmol/L H-89 led to all of the mouse eggs entering the M phase of mitosis. Furthermore, to study the role of PKA in regulating the phosphorylation status of S149 and S321 sites of cell division cycle 25B (CDC25B) on one-cell stage fertilized mouse eggs, pBSK-CDC25B-WT, pBSK-CDC25B-S149A, pBSK-CDC25B-S321A and pBSK-CDC25B-S149A/S321A were transcribed into mRNAs in vitro, then mRNAs were microinjected into S phase of mouse fertilized eggs and cultured in M16 medium pretreated with H-89. Then, the cleavage of fertilized eggs, maturation promoting factor (MPF) activity and phosphorylation status of CDC2-Tyr15 were observed. In the presence of 40 μmol/L H-89, the cleavage rate of fertilized eggs in CDC25B-S/A-mRNAs and CDC25B-WT-mRNA injected groups was significantly higher than that in the control groups, and the peak of MPF activity appeared in the CDC25B-S/A-mRNAs and CDC25B-WT-mRNA injected groups earlier than that in the control groups. CDC2-Tyr15 phosphorylation state was consistent with MPF activity. In conclusion, the present study suggests that PKA regulates the early development of mouse embryos by phosphorylation of S149 and S321 of CDC25B, which plays an important role in the regulation of G(2)/M transition in the mitotic cell cycle of fertilized mouse eggs.
Animals ; Cyclic AMP-Dependent Protein Kinases ; genetics ; physiology ; Embryonic Development ; physiology ; Female ; Male ; Mice ; Microinjections ; Mitosis ; drug effects ; Phosphorylation ; Serine ; genetics ; metabolism ; Zygote ; cytology ; growth & development ; cdc25 Phosphatases ; genetics ; metabolism

Infection of schistosomiasis japonica may eventually lead to liver fibrosis, and no effective antifibrotic therapies are available but liver transplantation. Hedgehog (HH) signaling pathway has been involved in the process and is a promising target for treating liver fibrosis. This study aimed to explore the effects of pentoxifylline (PTX) on liver fibrosis induced by schistosoma japonicum infection by inhibiting the HH signaling pathway. Phorbol12-myristate13-acetate (PMA) was used to induce human acute mononuclear leukemia cells THP-1 to differentiate into macrophages. The THP-1-derived macrophages were stimulated by soluble egg antigen (SEA), and the culture supernatants were collected for detection of activation of macrophages. Cell Counting Kit-8 (CCK-8) was used to detect the cytotoxicity of the culture supernatant and PTX on the LX-2 cells. The LX-2 cells were administered with activated culture supernatant from macrophages and(or) PTX to detect the transforming growth factor-β gene expression. The mRNA expression of shh and gli-1, key parts in HH signaling pathway, was detected. The mRNA expression of shh and gli-1 was increased in LX-2 cells treated with activated macrophages-derived culture supernatant, suggesting HH signaling pathway may play a key role in the activation process of hepatic stellate cells (HSCs). The expression of these genes decreased in LX-2 cells co-cultured with both activated macrophages-derived culture supernatant and PTX, indicating PTX could suppress the activation process of HSCs. In conclusion, these data provide evidence that PTX prevents liver fibrogenesis in vitro by the suppression of HH signaling pathway.
Animals ; Antigens, Helminth ; isolation & purification ; pharmacology ; Cell Culture Techniques ; Cell Differentiation ; drug effects ; Cell Line ; Culture Media, Conditioned ; chemistry ; pharmacology ; Gene Expression Regulation ; Hedgehog Proteins ; agonists ; antagonists & inhibitors ; genetics ; immunology ; Hepatic Stellate Cells ; cytology ; drug effects ; metabolism ; Humans ; Liver Cirrhosis ; metabolism ; parasitology ; prevention & control ; Macrophage Activation ; drug effects ; Macrophages ; cytology ; drug effects ; immunology ; Models, Biological ; Monocytes ; cytology ; drug effects ; metabolism ; Pentoxifylline ; pharmacology ; Phosphodiesterase Inhibitors ; pharmacology ; RNA, Messenger ; genetics ; immunology ; Schistosoma japonicum ; chemistry ; Signal Transduction ; Tetradecanoylphorbol Acetate ; pharmacology ; Zinc Finger Protein GLI1 ; genetics ; immunology ; Zygote ; chemistry