title: N-acetyl cysteine prolonged the developmental ability of mouse two-cell embryos against oxidative stress at refrigerated temperatures.
abstract: Cold storage of two-cell embryos at refrigerated temperatures is a useful means to ship genetically engineered mice. We previously reported that M2 medium maintained the developmental ability of two-cell embryos for 48 h at 4 °C, and offspring were obtained from embryos transported by a courier service under refrigerated temperatures. The limitation of 48 h practically restricts the shipping destination of the embryos. To enhance the applicability of the cold-storage technique, prolonging the time to maintain developmental ability of the embryos is required. Oxidative stress may be a cause of the declining developmental ability of cold-stored embryos. However, the effect of oxidative stress on developmental ability of embryos has not been investigated. We examined intracellular glutathione (GSH) levels of cold-stored two-cell embryos to evaluate the effect of oxidative and investigated the efficacy of adding N-acetyl cysteine (NAC) to the preservation medium on the developmental ability of cold-stored embryos and transported two-cell embryos at refrigerated temperatures. Intracellular GSH levels of two-cell embryos decreased by cold storage for longer than 72 h, whereas NAC recovered this reduction and improved the developmental ability of embryos cold-stored for 96 h. In the transport experiment, the developmental rate of transported two-cell embryos to offspring was increased by adding NAC to the preservation medium. We found that NAC prolonged the storage period of two-cell embryos and maintained the developmental ability by alleviating the reduction of intracellular GSH. These findings will improve the technique of cold-storage of two-cell embryos to facilitate efficient transport of genetically engineered mice worldwide.
authors.affiliation: Division of Reproductive Engineering, Center for Animal Resources and Development (CARD), Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto, 860-0811, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Horikoshi
authors.affiliation: Division of Reproductive Engineering, Center for Animal Resources and Development (CARD), Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto, 860-0811, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Takeo
authors.affiliation: Division of Reproductive Engineering, Center for Animal Resources and Development (CARD), Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto, 860-0811, Japan. Electronic address: nakagata@kumamoto-u.ac.jp.
authors.forename: Naomi
authors.initials: N
authors.lastname: Nakagata
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology*; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D003080:Cold Temperature; D015925:Cryopreservation / Q000379:methods*; D004622:Embryo, Mammalian; D005260:Female; D005978:Glutathione / Q000378:metabolism; D008297:Male; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D018384:Oxidative Stress / Q000187:drug effects
chemical_list: D000975:Antioxidants; D005978:Glutathione; D000111:Acetylcysteine
keywords: Cold storage; Intracellular GSH; Mouse; N-acetyl cysteine; Two-cell embryo