Aboelenain Mansour, Balboula Ahmed Zaky, Kawahara Manabu, El-Monem Montaser Abd, Zaabel Samy Moawad, Kim Sung-Woo, Nagano Masashi, Takahashi Masashi
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.
Laboratory of Animal Breeding and Reproduction, Department of Animal Science, Graduate School of Agriculture, Hokkaido University, Hokkaido, 060-8589, Japan.
Theriogenology. 2017 Mar 15;91:127-133. doi: 10.1016/j.theriogenology.2016.12.022. Epub 2016 Dec 23.
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.
最近，在体外成熟（IVM）和培养（IVC）过程中抑制组织蛋白酶B（CTSB）的活性提高了牛卵母细胞和胚胎的发育能力及质量。E-64是一种广泛用于抑制CTSB活性的抑制剂，然而，E-64不仅抑制CTSB活性，还抑制包括组织蛋白酶L（CTSL）、木瓜蛋白酶、钙蛋白酶和胰蛋白酶在内的其他蛋白酶的活性。维生素B6的催化活性形式吡哆醇在多个细胞过程中起关键作用，并且有能力抑制CTSB活性。然而，吡哆醇在牛卵母细胞IVM过程中是否具有改善作用仍然未知。在本研究中，我们调查了IVM期间补充吡哆醇对牛卵母细胞发育能力和所产生囊胚质量的影响。向成熟培养基中补充吡哆醇显著降低了牛卵丘细胞和卵母细胞中CTSB的活性。此外，吡哆醇提高了囊胚率和孵化囊胚率。此外，IVM期间吡哆醇的存在还通过增加总细胞数以及降低CTSB mRNA表达和凋亡率，显著提高了所产生胚胎的质量。这些结果表明，吡哆醇是提高牛卵母细胞发育能力和后续胚胎质量的一种有前景的工具。
