Lab. Microscopía Electrónica, Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, México.
Lab. Biología Molecular del Cáncer, Laboratorio 6, 2º piso. UMIEZ, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, Ciudad de México, México.
J Histochem Cytochem. 2019 Dec;67(12):873-889. doi: 10.1369/0022155419881127. Epub 2019 Oct 4.
Oocyte cell death is a normal process in the mammalian ovary during follicular growth. Recent reports have demonstrated the presence of pro-apoptotic and pro-autophagic proteins during oocyte elimination. The goal of this study was to identify the interactions between proteins involved in different types of programmed cell death in the same oocyte during follicular atresia. We evaluated the presence of Beclin 1 and its interaction with the pro-apoptotic proteins active caspase-3, Bax, and Bak by means of histochemical observations, ultrastructural immunodetection, and immunoprecipitation techniques in ovaries from prepubertal (28- and 33-day-old), juvenile (40-day-old), and young adult (90-day-old) rats. In this study, we identified that oocyte elimination occurred with a high quantity of pro-autophagic protein Beclin 1 and increased the presence of the pro-apoptotic proteins active caspase-3, Bax, and Bak. Conversely, the antiapoptotic protein Bcl-2 was reduced in oocytes from atretic follicles. In addition, Beclin 1 was shown to interact with active caspase-3 and Bax. Our results suggest that the increase in Beclin 1 is directly related to the rise of pro-apoptotic proteins, which could promote the apoptotic process during oocyte elimination.
卵母细胞细胞死亡是哺乳动物卵巢在卵泡生长过程中的一种正常现象。最近的报告表明，在卵母细胞排除过程中存在促凋亡和自噬蛋白。本研究的目的是鉴定在卵泡闭锁过程中同一卵母细胞中不同类型程序性细胞死亡相关蛋白之间的相互作用。我们通过组织化学观察、超微结构免疫检测和免疫沉淀技术，评估了在幼鼠（28 天和 33 天龄）、幼年鼠（40 天龄）和青年鼠（90 天龄）卵巢中 Beclin 1 及其与促凋亡蛋白活性半胱天冬酶-3、Bax 和 Bak 的相互作用的存在。在这项研究中，我们发现卵母细胞的消除伴随着大量的自噬蛋白 Beclin 1 的产生，并且促凋亡蛋白活性半胱天冬酶-3、Bax 和 Bak 的存在增加。相反，在闭锁卵泡中的卵母细胞中，抗凋亡蛋白 Bcl-2 减少。此外，Beclin 1 被证明与活性半胱天冬酶-3 和 Bax 相互作用。我们的结果表明，Beclin 1 的增加与促凋亡蛋白的增加直接相关，这可能促进卵母细胞消除过程中的凋亡过程。
