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Medium-throughput Screening Assays for Assessment of Effects on Ca2+-Signaling and Acrosome Reaction in Human Sperm
Published on: March 1, 2019
Relationship between sperm apoptosis signalling and oocyte penetration capacity
S Grunewald1, T M Said, U Paasch
1Department of Dermatology/Andrology Unit, European Academy of Andrology (EAA) Training Center, University of Leipzig, Leipzig, Germany.
International Journal of Andrology
|June 19, 2007
Summary
Human sperm showing signs of apoptosis, like externalized phosphatidylserine (EPS) and caspase activation, have reduced oocyte penetration capacity. Excluding these sperm may improve assisted reproduction success rates.
Area of Science:
- Reproductive Biology
- Cellular Biology
- Spermatozoa Function
Background:
- Human sperm can exhibit apoptosis-like features, including externalization of phosphatidylserine (EPS) and mitochondrial potential disruption.
- Caspase activation is also observed in human spermatozoa, indicating potential programmed cell death pathways.
Purpose of the Study:
- To investigate the association between apoptosis cascade activation in human sperm and their oocyte penetration capacity.
- To determine if apoptosis markers in sperm correlate with success in the zona-free hamster oocyte penetration assay (SPA).
Main Methods:
- Semen samples from 76 donors were analyzed using the zona-free hamster oocyte penetration assay (SPA).
- Apoptosis signalling was assessed via flow cytometry, measuring EPS, disrupted mitochondrial membrane potential (MMP), and activated caspase-3.
- Sperm underwent double density gradient centrifugation and capacitation for 3 hours prior to SPA.
Main Results:
- Semen samples with subnormal SPA (<20% penetrated oocytes) showed significantly higher levels of sperm with EPS, disrupted MMP, and activated caspase-3 compared to samples with normal SPA (>20%).
- All three measured apoptosis markers (EPS, disrupted MMP, activated caspase-3) demonstrated a significant negative correlation with sperm-oocyte penetration percentage (p < 0.01).
Conclusions:
- Apoptosis-related signalling in human sperm is negatively associated with their ability to penetrate oocytes.
- Excluding sperm exhibiting these apoptosis-related features could potentially enhance the success rates of assisted reproductive technologies (ART) like IUI and IVF.
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