title: Pyridoxine supplementation during oocyte maturation improves the development and quality of bovine preimplantation embryos.
abstract: Recently, inhibition of cathepsin B (CTSB) activity during in vitro maturation (IVM) and culture (IVC) improved the developmental competence and quality of bovine oocytes and embryos. E-64 is a widely used inhibitor to inhibit CTSB activity, however, E-64 inhibits not only CTSB activity but also the activities of other proteases including cathepsin L (CTSL), papain, calpain, and trypsin. Pyridoxine, the catalytically active form of vitamin B6, plays a crucial role in several cellular processes and has the ability to inhibit CTSB activity. However, whether pyridoxine has an improving effect during IVM of bovine oocytes is still unknown. In this study, we investigated the effect of pyridoxine supplementation during IVM on the developmental competence of bovine oocytes and the quality of the produced blastocysts. Supplementation of pyridoxine to the maturation medium significantly decreased the activity of CTSB in both bovine cumulus cells and oocytes. Moreover, pyridoxine improved both the blastocyst and hatched blastocyst rates. In addition, the presence of pyridoxine during IVM also significantly improved the quality of the produced embryos by increasing the total cell number as well as decreasing the CTSB mRNA expression and apoptotic rate. These results indicate that pyridoxine is a promising tool to improve the developmental competence of bovine oocytes and subsequent embryo quality.
authors.affiliation: Laboratory of Animal Breeding and Reproduction, Department of Animal Science, Graduate School of Agriculture, Hokkaido University, Hokkaido, 060-8589, Japan; Department of Theriogenology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, 35516, Egypt.
authors.forename: Mansour
authors.initials: M
authors.lastname: Aboelenain
authors.affiliation: Laboratory of Animal Breeding and Reproduction, Department of Animal Science, Graduate School of Agriculture, Hokkaido University, Hokkaido, 060-8589, Japan; Department of Theriogenology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, 35516, Egypt.
authors.forename: Ahmed Zaky
authors.initials: AZ
authors.lastname: Balboula
authors.affiliation: Laboratory of Animal Breeding and Reproduction, Department of Animal Science, Graduate School of Agriculture, Hokkaido University, Hokkaido, 060-8589, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Kawahara
authors.affiliation: Department of Theriogenology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, 35516, Egypt.
authors.forename: Abd
authors.initials: A
authors.lastname: El-Monem Montaser
authors.affiliation: Department of Theriogenology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, 35516, Egypt.
authors.forename: Samy Moawad
authors.initials: SM
authors.lastname: Zaabel
authors.affiliation: National Institute of Animal Science, Animal Genetic Resources Research Center, Namwon, 55717, South Korea.
authors.forename: Sung-Woo
authors.initials: SW
authors.lastname: Kim
authors.affiliation: Laboratory of Theriogenology, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, 060-0818, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Nagano
authors.affiliation: Laboratory of Animal Breeding and Reproduction, Department of Animal Science, Graduate School of Agriculture, Hokkaido University, Hokkaido, 060-8589, Japan. Electronic address: mmasashi@anim.agr.hokudai.ac.jp.
authors.forename: Masashi
authors.initials: M
authors.lastname: Takahashi
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000187:drug effects*; D002401:Cathepsin B / Q000037:antagonists & inhibitors; D002417:Cattle; D047108:Embryonic Development / Q000187:drug effects*; D059471:In Vitro Oocyte Maturation Techniques / Q000662:veterinary*; D011736:Pyridoxine / Q000494:pharmacology*
chemical_list: D002401:Cathepsin B; D011736:Pyridoxine
keywords: Bovine oocytes; Cathepsin B; Developmental competence; In vitro maturation; Pyridoxine