Increased sperm chromatin decondensation in selected nonapoptotic spermatozoa of patients with male infertility

Abstract

To evaluate the sperm chromatin decondensation (SCD) rates of the annexin-negative (nonapoptotic) sperm fraction of patients with infertility using hamster intracytoplasmic sperm injection (H-ICSI). In healthy donors, the depletion of apoptotic sperm using annexin V-based magnetic-activated cell separation (MACS) enhances hamster oocyte sperm penetration but does not increase SCD rates following H-ICSI. A prospective-controlled study. Male infertility clinic, European Academy of Andrology Center Leipzig. Twenty-one male infertility patients with subnormal spermiogram. Spermatozoa were separated by Annexin V-MACS. Apoptosis signaling (disruption of transmembrane mitochondrial potential, transmembrane mitochondrial potential [TMP], and activation of caspases-3 [CP3]) and SCD rates of human spermatozoa after hamster intracytoplasmic sperm injection. Infertility patients showed high levels of sperm with active CP3 and disrupted TMP, which correlated negatively with SCD rates. Annexin V-MACS resulted in a significant enrichment of spermatozoa with inactive CP3 and intact TMP in the annexin-negative fraction. Similarly, annexin-negative sperm had the highest SCD rates following H-ICSI compared with controls and annexin-positive sperm. These results suggest that nonapoptotic spermatozoa prepared by annexin V-MACS display higher early fertilization potential following ICSI. The technique should be evaluated in a clinical setting for its impact on ICSI outcomes in patients diagnosed with infertility.