title: Inhibition of cathepsin B activity reduces apoptosis by preventing cytochrome c release from mitochondria in porcine parthenotes.
abstract: Cathepsin B, a lysosomal cysteine protease of the papain family, has recently been implicated in the quality and developmental competence of bovine preimplantation embryos. In this study, to determine whether inhibition of cathepsin B activity can improve porcine oocyte maturation and early embryo developmental competence, we supplemented in vitro maturation or embryo culture media with E-64, a cathepsin B inhibitor. Cathepsin B activity was high in poor quality germinal vesicle stage oocytes, but no differences in mRNA expression or protein localization were observed between good and poor quality oocytes, which were categorized based on morphology. Following treatment with 1 μM E-64, cathepsin B activity sharply decreased in 4-cell and blastocyst stage embryos. E-64 had no effect on cell number but significantly (P < 0.05) increased blastocyst formation and decreased the number of apoptotic cells in blastocysts. It also significantly (P < 0.05) enhanced mitochondrial membrane potential in blastocysts, reducing the release of cytochrome c and resulting in decreased expression of Caspase-3 and Caspase-9. In conclusion, inhibition of cathepsin B activity in porcine parthenotes using 1 μM E-64 resulted in attenuation of apoptosis via a reduction in the release of cytochrome c from mitochondria.
authors.affiliation: Department of Animal Sciences, Chungbuk National University, Chungbuk 361-763, Republic of Korea.
authors.forename: Seon-Hyang
authors.initials: SH
authors.lastname: Kim
authors.forename: Ming-Hui
authors.initials: MH
authors.lastname: Zhao
authors.forename: Shuang
authors.initials: S
authors.lastname: Liang
authors.forename: Xiang-Shun
authors.initials: XS
authors.lastname: Cui
authors.forename: Nam-Hyung
authors.initials: NH
authors.lastname: Kim
mesh_terms: D000003:Abattoirs; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001755:Blastocyst / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D053148:Caspase 3 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D053453:Caspase 9 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D061945:Caspase Inhibitors / Q000494:pharmacology*; D002401:Cathepsin B / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004477:Ectogenesis / Q000187:drug effects*; D046149:Embryo Culture Techniques / Q000662:veterinary; D004794:Enzyme Repression / Q000187:drug effects; D005260:Female; D059471:In Vitro Oocyte Maturation Techniques / Q000662:veterinary; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D053652:Nuclear Transfer Techniques / Q000662:veterinary; D009866:Oogenesis / Q000187:drug effects*; D010312:Parthenogenesis; D056910:Republic of Korea; D034421:Sus scrofa
chemical_list: D061945:Caspase Inhibitors; D053148:Caspase 3; D053453:Caspase 9; D002401:Cathepsin B; D007930:Leucine; C024974:E 64