Abstract：
Couples increasingly experience infertility and seek help from assisted reproductive techniques to become pregnant. However, 5%-15% of the couples that are selected for in vitro fertilisation (IVF) experience a total fertilisation failure (TFF), where no zygotes develop despite oocytes and semen parameters appear to be normal. We hypothesise that TFF during IVF could be related to improper membrane fusion of gametes.
To investigate the membrane integrity and fusion proteins in spermatozoa from men in couples experiencing TFF.
A total of 33 infertile couples, 17 of which experienced TFF during IVF and 16 matched control couples with normal IVF fertilisation rates, were selected and the men re-called to deliver an additional semen sample. Proteins involved in gamete membrane fusion on spermatozoa (IZUMO1, SPESP1 and Syncytin-1) as well as O-glycosylation patterns (Tn and GALNT3), were investigated by immunofluorescence. The DNA fragmentation index, acrosomal integrity and viability of spermatozoa were determined by flow and image cytometry.
No significant changes in the expression of GALNT3, Tn and Syncytin-1 were observed between the TFF and control groups. The fraction of spermatozoa expressing SPESP1, the median IZUMO1 staining intensity, and the percentage of viable acrosome-intact spermatozoa were significantly lower in the TFF group compared to controls. Furthermore, following progesterone-induced acrosomal exocytosis, a significant difference in the fraction of spermatozoa expressing SPESP1 and the median IZUMO1 staining intensity were observed between the control and TFF group.
Our results indicate that acrosomal exocytosis, IZUMO1 and SPESP1 expression in spermatozoa could play a crucial role in achieving fertilisation during IVF. However, the size of our cohort was quite small, and our results need to be validated with quantitative methods in larger cohorts.
To investigate the membrane integrity and fusion proteins in spermatozoa from men in couples experiencing TFF.
A total of 33 infertile couples, 17 of which experienced TFF during IVF and 16 matched control couples with normal IVF fertilisation rates, were selected and the men re-called to deliver an additional semen sample. Proteins involved in gamete membrane fusion on spermatozoa (IZUMO1, SPESP1 and Syncytin-1) as well as O-glycosylation patterns (Tn and GALNT3), were investigated by immunofluorescence. The DNA fragmentation index, acrosomal integrity and viability of spermatozoa were determined by flow and image cytometry.
No significant changes in the expression of GALNT3, Tn and Syncytin-1 were observed between the TFF and control groups. The fraction of spermatozoa expressing SPESP1, the median IZUMO1 staining intensity, and the percentage of viable acrosome-intact spermatozoa were significantly lower in the TFF group compared to controls. Furthermore, following progesterone-induced acrosomal exocytosis, a significant difference in the fraction of spermatozoa expressing SPESP1 and the median IZUMO1 staining intensity were observed between the control and TFF group.
Our results indicate that acrosomal exocytosis, IZUMO1 and SPESP1 expression in spermatozoa could play a crucial role in achieving fertilisation during IVF. However, the size of our cohort was quite small, and our results need to be validated with quantitative methods in larger cohorts.
摘要：
夫妻越来越多地经历不孕症，并寻求辅助生殖技术的帮助以怀孕。然而,选择进行体外受精（IVF）的夫妇中有5％-15％经历了完全受精失败（TFF），尽管卵母细胞和精液参数似乎正常，但没有受精卵发育。我们假设IVF期间的TFF可能与配子的膜融合不当有关。
研究经历TFF的男性精子中的膜完整性和融合蛋白。
共有33对不孕夫妇,其中17对在IVF期间经历了TFF，16对具有正常IVF受精率的配对对照夫妇，被选中，男性再次打电话来提供额外的精液样本。参与精子配子膜融合的蛋白质（IZUMO1，SPESP1和Syncytin-1）以及O-糖基化模式（Tn和GALNT3），通过免疫荧光进行了研究。DNA片段化指数,通过流式细胞术和图像细胞术确定精子的顶体完整性和活力。
在TFF组和对照组之间没有观察到GALNT3、Tn和Syncytin-1表达的显著变化。精子表达SPESP1的部分，中位数IZUMO1染色强度，与对照组相比，TFF组有活力的顶体完整精子的百分比显着降低。此外，孕酮诱导的顶体胞吐后，在对照组和TFF组之间观察到表达SPESP1的精子分数和中位数IZUMO1染色强度的显着差异。
我们的结果表明顶体胞吐，精子中IZUMO1和SPESP1的表达可能在IVF期间实现受精中起关键作用。然而,我们的队伍规模很小，我们的结果需要在更大的队列中使用定量方法进行验证.
研究经历TFF的男性精子中的膜完整性和融合蛋白。
共有33对不孕夫妇,其中17对在IVF期间经历了TFF，16对具有正常IVF受精率的配对对照夫妇，被选中，男性再次打电话来提供额外的精液样本。参与精子配子膜融合的蛋白质（IZUMO1，SPESP1和Syncytin-1）以及O-糖基化模式（Tn和GALNT3），通过免疫荧光进行了研究。DNA片段化指数,通过流式细胞术和图像细胞术确定精子的顶体完整性和活力。
在TFF组和对照组之间没有观察到GALNT3、Tn和Syncytin-1表达的显著变化。精子表达SPESP1的部分，中位数IZUMO1染色强度，与对照组相比，TFF组有活力的顶体完整精子的百分比显着降低。此外，孕酮诱导的顶体胞吐后，在对照组和TFF组之间观察到表达SPESP1的精子分数和中位数IZUMO1染色强度的显着差异。
我们的结果表明顶体胞吐，精子中IZUMO1和SPESP1的表达可能在IVF期间实现受精中起关键作用。然而,我们的队伍规模很小，我们的结果需要在更大的队列中使用定量方法进行验证.
