title: Effect of ganglioside GT1b on the in vitro maturation of porcine oocytes and embryonic development.
abstract: Ganglioside is an acidic glycosphingolipid with sialic acids residues. This study was performed to investigate the effect and mechanism of ganglioside GT1b in porcine oocytes in the process of in vitro maturation (IVM) and preimplantation development. Metaphase II (MII) rates were significantly (P < 0.05) different between the control group and the 5 nM GT1b treatment group. Intracellular glutathione (GSH) levels in oocytes matured with 5 nM and 20 nM and GT1b decreased significantly (P < 0.05). The 10 nM group showed a significant (P < 0.05) decrease in intracellular reactive oxygen species (ROS) levels compared with the control group. Subsequently, the level of intracellular Ca(2+) in oocytes treated with different concentrations of GT1b was measured. Intracellular Ca(2+) was significantly (P < 0.05) increased with a higher concentration of GT1b in a dose-dependent manner. Real-time PCR was performed and showed that the expression of bradykinin 2 receptor (B2R) and calcium/calmodulin-dependent protein kinase II delta (CaMKIIδ) in cumulus cells was significantly (P < 0.05) decreased in the 20 nM GT1b treatment group. Treatment with 5 nM GT1b significantly (P < 0.05) decreased the expression of CaMKIIδ. In oocytes, treatment with 5 nM GT1b significantly (P < 0.05) decreased CaMKIIγ and POU5F1 (POU domain, class 5, transcription factor 1). However, treatment with 20 nM GT1b significantly (P < 0.05) increased the expression of POU5F1. Finally, embryonic developmental data showed no significant differences in the two experiments (parthenogenesis and in vitro fertilization). In conclusion, the results of the present study indicated that GT1b plays an important role in increasing the nuclear maturation rate and decreasing the intracellular ROS levels during IVM. However, GT1b inhibited maturation of the cytoplasm by maintaining intracellular Ca(2+) in the process of oocyte maturation regardless of the cell cycle stage. Therefore, GT1b is thought to act on another mechanism that controls intracellular Ca(2+).
authors.affiliation: Laboratory of Veterinary Embryology and Biotechnology, College of Veterinary Medicine, Chungbuk National University, Chungbuk 362-763, South Korea.
authors.forename: Seon-Ung
authors.initials: SU
authors.lastname: Hwang
authors.forename: Yubyeol
authors.initials: Y
authors.lastname: Jeon
authors.forename: Junchul David
authors.initials: JD
authors.lastname: Yoon
authors.forename: Lian
authors.initials: L
authors.lastname: Cai
authors.forename: Eunhye
authors.initials: E
authors.lastname: Kim
authors.forename: Hyunju
authors.initials: H
authors.lastname: Yoo
authors.forename: Kyu-Jun
authors.initials: KJ
authors.lastname: Kim
authors.forename: Kyu Mi
authors.initials: KM
authors.lastname: Park
authors.forename: Minghui
authors.initials: M
authors.lastname: Jin
authors.forename: Hyunggee
authors.initials: H
authors.lastname: Kim
authors.forename: Sang-Hwan
authors.initials: SH
authors.lastname: Hyun
mesh_terms: D000818:Animals; D002118:Calcium / Q000032:analysis; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro; D005732:Gangliosides / Q000502:physiology*; D005978:Glutathione / Q000032:analysis; D059471:In Vitro Oocyte Maturation Techniques; D012333:RNA, Messenger / Q000032:analysis; D017382:Reactive Oxygen Species; D060888:Real-Time Polymerase Chain Reaction; D043782:Receptor, Bradykinin B2 / Q000032:analysis; D013552:Swine / Q000502:physiology*
chemical_list: D005732:Gangliosides; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D043782:Receptor, Bradykinin B2; C016481:trisialoganglioside GT1; D005978:Glutathione; D002118:Calcium