Paternal Sperm DNA Damage During Capacitation And Acrosome Reaction Is Increased In Patients With Unexplained Recurrent Spontaneous Abortion

Objective:to explore the realationship between the recurrent spontaneous abortion(RSA) and sperm DNA damage and its possible mechanism during capacitation andacrosome reaction in vitro.Methods:we firstly studied25men whose partners had a history of unexplained RSA(RSA group;n=25) and25healthy men (control group; n=25) using sperm chromatinstructure assay (SCSA) during capacitation and acrosome reaction in vitro.To explorethe possible mechanism,and then we tested the sperm intracellular ROS levels beforeand after the induced acrosome reaction.the unexplained recurrent abortion group (n=25) and the normal fertility group (n=25) of sperm, have been respectively proven toliquid and calcium ionophore A23187(IA) for0.5h,1h,2h,4h after inductiontreatment. At last coomassie brilliant blue for detecting different time points ofacrosome reaction rate. And flow cytometry instrument for testing different time pointsof DFI and ROS.Results:During incubation of the semen at37℃, the sperm DNA damage in RSA andcontrol groups were examined at0.5h,1h,2h and4h by SCSA. Although DFI in RSAgroup was constantly higher than that in the control, the DFI values in both groupsremained relatively stable. Moreover, the increased rate of DFI values were similar in both RSA and control groups. In the process of induced capacitation and acrosomereaction in vitro, the DNA damage was also examined in the both group at the time of0.5h,1h,2h and4h. The DFI values in both groups increased time. ComparIing the rateof DFI increase between the two groups, we found that the rate of DFI increase in RSAgroup was significantly higher than that in control group4hours after the acrosomereaction (P=0.042).At the same time,we tested ROS levels in semen of the RSA andcontrol groups after the liquefaction. The semen ROS levels in all samples wereexamined by MDA method, and no difference were found in the whole process ofincubation. Then, the semen samples were stained with PIand DHR123, and checkedby flow cytometry to examine the sperm ROS. During the incubation period at37℃,the intracellular ROS levels in RSA and control groups significantly increased after2hours, and both groups were in the same increase rate. However, after the process ofcapacitation and acrosome reaction, we found that the of intracellular was higher inRSA group than that in the control group at4hour time point.Conclusion:Unexplained recurrent miscarriage and sperm DNA damage have a certaincorrelation.Patients with unexplained recurrent miscarriage spouses will produce moresperm DNA damage in the process of capacity and acrosome reaction. Its mechanismmay be anti-oxidationand oxidation system imbalance in vitro capacition and acrosomereaction processin, resulting in reactive oxygen species increased, damage to spermintegrity, chromosome DNA rupture.