Ghent-Fertility and Stem Cell Team (G-FaST), Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium.
Ghent University (UGent Honours Programme in Life Sciences), Ghent, Belgium.
Reprod Biomed Online. 2019 Apr;38(4):497-507. doi: 10.1016/j.rbmo.2018.12.035. Epub 2018 Dec 23.
Can oocyte-related activation deficiencies be evaluated in oocytes that failed to fertilize after intracytoplasmic sperm injection (ICSI) combined with assisted oocyte activation (AOA)?
Evaluation of the spindle-chromosome complexes and intracellular distribution of inositol trisphosphate type 1 receptors (IP3R1) in in-vitro matured (IVM) and failed-to-fertilize oocytes from patients undergoing AOA. Assessment of the oocyte-related Ca releasing capacity in response to Ca ionophores and sperm microinjection in oocytes that failed to fertilize after ICSI or ICSI-AOA.
IVM oocytes from patients undergoing conventional ICSI (control) and ICSI-AOA (study group) revealed a similar normalcy of spindle-chromosome complexes and distribution patterns of IP3R1. Failed-to-fertilize oocytes from both groups showed significant differences in proportion of normal or abnormal spindle-chromosome complex conformations. However, migration of IP3R1 was identified in a higher proportion of failed-to-fertilize oocytes after ICSI-AOA than after conventional ICSI. It was further observed that oocytes which failed to fertilize, either after ICSI or ICSI-AOA, mostly retain their capacity to respond to stimuli such as exposure to Ca ionophores or to sperm microinjection.
Evaluation of spindle-chromosome normalcy and distribution of IP3R1 does not help identify the presence of Ca releasing deficiencies in these oocytes. However, oocyte Ca analysis adds value in identifying Ca releasing incapacity of oocytes that failed to fertilize after ICSI or ICSI-AOA. Some patients experiencing fertilization failure after ICSI-AOA present with a suspected activation deficiency downstream of the Ca machinery, which cannot be overcome by ICSI-AOA based on the use of Ca ionophores.
卵母细胞相关激活缺陷能否在卵母细胞受精失败后进行胞浆内精子注射（ICSI）结合辅助卵母细胞激活（AOA）时进行评估？
评估接受 AOA 的患者体外成熟（IVM）和受精失败卵母细胞中的纺锤体-染色体复合物和肌醇 1,4,5-三磷酸受体 1（IP3R1）的细胞内分布。评估受精失败的卵母细胞对钙离子载体和精子微注射的 Ca 释放能力，这些卵母细胞在 ICSI 或 ICSI-AOA 后未受精。
接受常规 ICSI（对照组）和 ICSI-AOA（研究组）的 IVM 卵母细胞显示出相似的纺锤体-染色体复合物正常性和 IP3R1 分布模式。两组受精失败的卵母细胞在正常或异常纺锤体-染色体复合物构象的比例上均存在显著差异。然而，在 ICSI-AOA 后，与常规 ICSI 相比，更多的受精失败卵母细胞中观察到 IP3R1 的迁移。进一步观察到，无论是在 ICSI 还是 ICSI-AOA 后受精失败的卵母细胞，大多数仍保留对刺激的反应能力，例如暴露于钙离子载体或精子微注射。
评估纺锤体-染色体正常性和 IP3R1 的分布并不能帮助识别这些卵母细胞中 Ca 释放缺陷的存在。然而，卵母细胞 Ca 分析有助于识别在 ICSI 或 ICSI-AOA 后受精失败的卵母细胞的 Ca 释放能力不足。一些在 ICSI-AOA 后经历受精失败的患者表现出 Ca 机制下游的可疑激活缺陷，这不能通过基于使用钙离子载体的 ICSI-AOA 来克服。
