Germ cell apoptosis in men with complete and incomplete spermiogenesis failure

Area of Science:

• Reproductive Biology
• Cell Biology
• Andrology

Background:

• Nonobstructive azoospermia presents challenges for male fertility treatments.
• Spermatid conception programs aim to utilize advanced germ cells for fertilization.
• Understanding germ cell apoptosis is crucial for assessing reproductive potential.

Purpose of the Study:

• To evaluate germ cell apoptosis in men with nonobstructive azoospermia undergoing spermatid conception.
• To compare apoptosis frequencies between complete and incomplete spermiogenesis failure.
• To correlate apoptosis markers with spermatid conception success.

Main Methods:

• Analysis of testicular biopsy samples from 11 men with nonobstructive azoospermia.
• Assessment of germ cell apoptosis using terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) and annexin-V binding.
• Double-fluorescence labelling combined with proacrosin immunocytochemistry to identify germ cells.

Main Results:

• Patients with complete spermiogenesis failure showed significantly higher frequencies of apoptosis in primary spermatocytes and round spermatids compared to incomplete failure.
• Apoptosis-related phosphatidylserine externalization was infrequent until advanced spermatogenesis stages.
• High DNA damage in round spermatids correlated with lower spermatid conception success rates.

Conclusions:

• Elevated germ cell apoptosis, particularly DNA damage in round spermatids, is associated with complete spermiogenesis failure.
• The limited externalization of phosphatidylserine suggests potential phagocytosis resistance in early apoptotic germ cells.
• Apoptosis evaluation can serve as a predictive marker for spermatid conception outcomes in infertile men.