Dynamic status of lysosomal cathepsin in bovine oocytes and preimplantation embryos
Dynamic status of lysosomal cathepsin in bovine oocytes and preimplantation embryos
复制标题
DOI：
10.1262/jrd.2019-115
复制
发表时间：
2020-02-01
影响因子：
1.8
通讯作者：
Takahashi, Masashi
中科院分区：
文献类型：
--
作者：
Li, Jianye;Maeji, Mana;Takahashi, Masashi
溶酶体组织蛋白酶，特别是组织蛋白酶B（CTSB），在着床、妊娠和胚胎发育中起重要作用。然而，牛卵母细胞和植入前胚胎中溶酶体组织蛋白酶的动态变化的机制却知之甚少。在本研究中，我们研究了牛卵母细胞和植入前胚胎中CTSB的基因表达、活性和免疫定位以及溶酶体活性的动态变化。几个组织蛋白酶相关基因的基因表达分析后，CTSB，CTSD和CTSZ的转录水平是最高的中期II（MII）的卵母细胞，然后从8细胞胚胎阶段显着下降。CTSB活性在1-细胞期和桑椹期胚胎中显著增加。溶酶体活性在1-细胞和桑椹胚阶段也显著较高，这与CTSB活性一致。然而，CTSB的免疫定位没有显示出类似的CTSB和溶酶体活性的模式。我们还发现CTSB转录本在滋养外胚层（TE）中的表达水平显著高于内细胞团（ICM），而CTSB的活性和免疫定位显示出相反的模式，即在ICM中显著高于TE。通过使用分离的ICM和TE的相同分析证实了这些模式。我们的研究结果表明，溶酶体CTSB在胚胎发育和分化过程中起着关键作用，特别是受精和分化期。
Lysosomal cathepsin, in particular cathepsin B (CTSB), plays an important role in implantation, pregnancy, and embryonic development. However, little is known about the mechanism related to the dynamic status of lysosomal cathepsins in bovine oocytes and preimplantation embryos. In the present study, we investigated the dynamics of gene expression, activity, and immunolocalization of CTSB, as well as the activities of lysosome, in bovine oocytes and preimplantation embryos. After gene expression analysis of several cathepsin-related genes, transcript levels of CTSB, CTSD and CTSZ were highest in Metaphase II (MII) oocytes followed by a significant decrease from the 8-cell embryo stage. Activity of CTSB showed a significant increase in 1-cell and morula stage embryos. Lysosomal activity was also significant higher in 1-cell and morula stages, which was consistent with CTSB activities. However, immunolocalization of CTSB did not show the similar pattern of CTSB and lysosomal activities. We also found significantly higher expression levels of CTSB transcript in the trophectoderm (TE) compared to inner cell mass (ICM), whereas activity and immunolocalization of CTSB showed an opposite pattern, i.e. significantly higher in ICM than TE. These patterns were confirmed by the same analysis using separated ICM and TE. Our results suggest that lysosomal CTSB has a pivotal role during embryonic development and differentiation, especially fertilization and the differentiation period.