Pezhman M, Hosseini S M, Ostadhosseini S, Rouhollahi Varnosfaderani Sh, Sefid F, Nasr-Esfahani M H
Department of Reproductive Biotechnology, Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, ACECR, Royan St., Salman St., Khorasgan, Jey St, Isfahan, 8159358686, Iran.
Department of Biology, Faculty of Science, Nour Danesh Institute of Higher Education, Isfahan, Meymeh, Iran.
BMC Dev Biol. 2017 Jul 4;17(1):10. doi: 10.1186/s12861-017-0152-2.
Cathepsin B is a lysosomal cysteine protease involved in apoptosis and oocytes which have lower developmental competence show higher expression of Cathepsin B. Furthermore, expression of Cathepsin B show a decreasing trend from oocyte toward blastocyst stage.
Present study assessed the effect of cathepsin B inhibitor, E-64, on developmental competency and cryo-survival of pre-implantation ovine IVF derived embryos. Cathepsin B inhibitor was added during day 3 to 8 of development. One μM E-64 was defined as the optimal concentration required for improving blastocyst rate. This concentration also reduced DNA fragmentation and BAX as apoptotic markers while increasing total cell number per blastocyst and improving anti-apoptotic marker, the BCL2. We further showed that addition of 1.0 μM of E-64 during day 3 to 8 of development improved re-expansion and hatching rates of blastocysts post vitrification. E-64 also reduced rate of DNA fragmentation and BAX expression and increased total cell number per blastocyst and BCL2 expression post vitrification. However, addition of E-64 post vitrification reduced the hatching rate.
Therefore, it can be concluded that inhibition of cathepsin B in IVC, not only improves quality and quantity of blastocysts but also improves the cryo-survival of in vitro derived blastocysts.
组织蛋白酶B是一种溶酶体半胱氨酸蛋白酶，参与细胞凋亡，发育能力较低的卵母细胞中组织蛋白酶B的表达较高。此外，从卵母细胞到囊胚阶段，组织蛋白酶B的表达呈下降趋势。
本研究评估了组织蛋白酶B抑制剂E-64对体外受精的绵羊植入前胚胎发育能力和冷冻存活率的影响。在发育的第3天至第8天添加组织蛋白酶B抑制剂。1μM E-64被确定为提高囊胚率所需的最佳浓度。该浓度还降低了作为凋亡标志物的DNA片段化和BAX水平，同时增加了每个囊胚的总细胞数，并改善了抗凋亡标志物BCL2的水平。我们进一步表明，在发育的第3天至第8天添加1.0μM E-64可提高玻璃化后囊胚的再扩张率和孵化率。E-64还降低了玻璃化后DNA片段化率和BAX表达水平，增加了每个囊胚的总细胞数和BCL2表达水平。然而，玻璃化后添加E-64会降低孵化率。
因此，可以得出结论，抑制体外培养中的组织蛋白酶B，不仅能提高囊胚的质量和数量，还能提高体外培养囊胚的冷冻存活率。
