Relationship between Sperm Vacuoles, Morphology, DNA Damage, Chromatin State, and Oxidative Stress [7B

Abstract

INTRODUCTION: Some studies found that the presence of sperm nuclear vacuoles is positively correlated with DNA fragmentation. Our objectives are: 1) Evaluate the quantity and size of vacuoles and their association with morphology, DNA damage, and chromatin compaction in semen from men who underwent assisted reproductive treatments; and 2) Investigate the effect of oxidative stress on DNA fragmentation. METHODS: Semen samples from 75 men were analyzed and the number and size of vacuoles, DNA fragmentation, and chromatin compaction state were determined via MSOME, TUNEL, and acridine orange (AO) respectively. Furthermore, the level of vitality, DNA fragmentation, and chromatin compaction were evaluated prior to and after 4 hours of oxidative stress (H202). RESULTS: In the Kruger ≥4% population, spermatozoa with one or more vacuoles that covered >20% of the nuclear surface had more DNA fragmentation compared to those that covered less. Also, spermatozoa with 1 large or several vacuoles had a chromatin compaction state that was more susceptible to acid-induced DNA denaturation compared to those with other vacuoles pattern. In the Kruger<4% population, there is no difference in DNA fragmentation between spermatozoa with or without vacuoles. After 4 hours, H2O2 did not affect the spermatozoa vitality but did increased the DNA fragmentation. CONCLUSION: In patients with Kruger ≥14%, selecting a spermatozoon without vacuoles for ICSI may result in one with less DNA fragmentation. In patients with Kruger<4%, vacuoles should not be a factor in spermatozoon selection; time spent examining vacuoles may increase exposure to oxidative stress resulting in greater DNA damage.