Mechanisms and clinical correlates of sperm DNA damage

Abstract

Among the different DNA anomalies that can be present in the male gamete, DNA fragmentation is the most frequent, particularly in infertile subjects. There is now consistent evidence that a sperm containing fragmented DNA can be alive, motile, morphologically normal and able to fertilize an oocyte. There is also evidence that the oocyte is able to repair DNA damage; however, the extent of this repair depends on the type of DNA damage present in the sperm, as well as on the quality of the oocyte. Thus, it is important to understand the possible consequences of sperm DNA fragmentation (SDF) for embryo development, implantation, pregnancy outcome and the health of progeny conceived, both naturally and by assisted reproductive technology (ART). At present, data on the consequences of SDF for reproduction are scarce and, in many ways, inconsistent. The differences in study conclusions might result from the different methods used to detect SDF, the study design and the inclusion criteria. Consequently, it is difficult to decide whether SDF testing should be carried out in fertility assessment and ART. It is clear that there is an urgent need for the standardisation of the methods and for additional clinical studies on the impact of SDF on ART outcomes.

Effects of aging on the male reproductive system

“…Low and medium concentrations of ROS are involved in cellular defense against infection agents, signal transduction, and response against mitogens, carboxylation, peroxidation, Pasqualotto et al [28] 0.03 ml [33] and reduction of ribonucleotides; however, high levels of ROS lead to various cellular damage [54][55][56][57][58][59]. ROS induced DNA damage involves base modifications, abasic sites, single strand (ss) and double strand (ds) DNA breaks, and DNA protein cross-links [60][61][62].…”

Protective effects of exogenous gangliosides on ROS-induced changes in human spermatozoa

“…4,15,71,72 Recent studies have shown that DNA fragmentation can be primarily attributed to cryopreservation-induced ROS. [73][74][75] In contrast to superoxide anion, the more stable H 2 O 2 readily crosses the plasma membrane and is responsible for DNA oxidative damage. 76 Because DNA integrity is essential for achieving fertilisation and enabling embryo development in assisted reproductive technologies, the preservation of DNA during cryostorage is of extreme importance.…”

Intervention improves assisted conception intracytoplasmic sperm injection outcomes for patients with high levels of sperm DNA fragmentation: a retrospective analysis

“…The use of flow cytometry in SCSA makes standardization difficult because of a degree of user-dependent skill and data interpretation. There is a need for standardization of SDF testing and further studies that assess the clinical relevance of SDF (Tamburrino et al, 2012;Drobnis & Johnson, 2015).…”