Høst E, Mikkelsen A L, Lindenberg S, Smidt-Jensen S
Ciconia Research and Development Aps, Herlev Amtssygehus, University of Copenhagen, Denmark.
Acta Obstet Gynecol Scand. 2000 Nov;79(11):936-40.
The purpose of this study was to determine the incidence of apoptosis in cumulus cells, and correlate these findings with the maturation stage, fertilization rate and embryo score of the corresponding oocyte, in couples undergoing ICSI due to a male factor.
The study group consisted of 21 couples where ICSI was performed. The total number of oocyte-cumulus complexes retrieved was 164. Sperm samples were assessed according to the WHO manual, morphology according to the strict criteria and for the presence of apoptosis. The degree of apoptotic DNA fragmentation was determined using the free 3'OH DNA termini in situ with chemically labeled and unlabeled nucleotides. The study was blinded for the technician involved in the assessments of apoptosis in the cumulus cells, apoptosis and morphology in spermatozoa. Ovarian hyperstimulation was carried out according to a long down regulation protocol using GnRH, recFSH and hCG. A maximum of 3 embryos were transferred on day 2 after ICSI.
This study demonstrated that the incidence of apoptosis was significantly higher in cumulus cells from germinal vesicle and metaphase I oocytes compared to cumulus cells from metaphase II oocytes (p<0.0001). Non-fertilized metaphase II oocytes showed significantly higher incidence of apoptosis in cumulus cells compared to fertilized metaphase II oocytes (p=0.0082). Furthermore, apoptosis in spermatozoa had an impact on the embryo score (p=0.0087).
Comparing apoptosis in cumulus cells with maturity of the corresponding oocytes, a significantly higher degree was found related to immature oocytes. Apoptosis in cumulus cells from human metaphase II oocytes impaired the fertilization rate. The degree of fragmentation in the embryo might be correlated to apoptosis in the spermatozoa.
本研究旨在确定因男性因素接受卵胞浆内单精子注射（ICSI）的夫妇中，卵丘细胞凋亡的发生率，并将这些结果与相应卵母细胞的成熟阶段、受精率和胚胎评分相关联。
研究组由21对接受ICSI的夫妇组成。共获取164个卵母细胞 - 卵丘复合体。根据世界卫生组织手册评估精子样本，按照严格标准评估形态并检测凋亡情况。使用化学标记和未标记的核苷酸原位检测游离3'OH DNA末端，以确定凋亡DNA片段化程度。参与评估卵丘细胞凋亡、精子凋亡和形态的技术人员对研究进行盲法操作。采用促性腺激素释放激素（GnRH）、重组促卵泡素（recFSH）和人绒毛膜促性腺激素（hCG），按照长方案进行卵巢超刺激。ICSI后第2天最多移植3个胚胎。
本研究表明，与来自减数第二次分裂中期（MII）卵母细胞的卵丘细胞相比，来自生发泡期和减数第一次分裂中期（MI）卵母细胞的卵丘细胞凋亡发生率显著更高（p<0.0001）。未受精的MII卵母细胞的卵丘细胞凋亡发生率显著高于受精的MII卵母细胞（p = 0.0082）。此外，精子凋亡对胚胎评分有影响（p = 0.0087）。
将卵丘细胞凋亡与相应卵母细胞的成熟度进行比较，发现与未成熟卵母细胞相关的凋亡程度显著更高。人MII卵母细胞的卵丘细胞凋亡会损害受精率。胚胎的碎片化程度可能与精子凋亡相关。
