[ATM/H2AX and repair of sperm-DNA damage during cryopreservation]

Semen cryopreservation is an important method in assisted reproductive technology, but meanwhile it is complicated by cryodamage to spermatozoa. Mechanisms behind the cryodamage to spermatozoa are thought to be multifactorial, and the excessive generation of reactive oxygen species (ROS) has been suggested as a major contributing factor. DNA-damaged sperm is also capable of fertilizing oocytes, significantly affecting the outcome of reproduction. As a sensor of DNA damage responses, protein kinase ATM (ataxia telangiectasia mutated) can be initiated through rapid intermolecular autophosphorylation induced by DNA damage, phosphorylate various proteins, and amplify the responses to DNA damage. After DNA damage, histone H2AX is activated by ATM, which contributes to the repair of sperm-DNA damage after fertilization and regulates the cell cycle during embryo development. Given the important role of the ATM/H2AX signaling pathway in the response to and repair of DNA damage induced by oxidative stress, it may mediate the repair of sperm-DNA damage resulting from cryopreservation.