The Role And Mechanism Of Mitochondria And Mitophagy In Asthenospermia

ObjectiveIn order to provide new therapeutic theory evidence for the asthenospermia(AZS)patients in China,this study observe the phenomenon of autophagy and mitophaghy of ejaculated sperm in the male patients with AZS,and determine the role of mitochondria and their autophagy among patients with different level of AZS in China.MethodsAccording to the WHO manual(the 5th edition),published in 2010,semen samples were collected from the Andrology clinics in the People's hospital which affiliated to Hubei University of Medicine,and were divided into 4 group,the normal control group,mild group,moderate group and severe group(30 cases in each group).After fixing the specimens of each group by the electron microscope fixative solution,electron microscope detection was performed to analyze the number and morphology of mitochondria and the distribution of autophagosomes in the sperm of each group.The concentration curves of T-SOD and MDA in sperm plasma were detected using Percoll gradient centrifugation method.The relationship between sperm motility and mitochondrial damage was evaluated by the above comprehensive indexes.Western-blot method was used to judge the expression of TOM20,p62,LC3 and other proteins related to mitochondrial autophagy.LC3 and mitochondrial fluorescence spots in sperm were detected by confocal laser microscopy to exam if autophagy in sperm is the idiopathic mitochondrial autophagy.ResultsThe concentration of MDA showed a trend of drop rapidly after a progressive increasing in the sperm among different level of AZS,but still higher than normal control group(P <0.05),T-SOD concentration showed a decreasing tendency,the severe AZS group is higher than the moderate group,but is still lower than the normal control group.The results of electron microscopy showed that the number of mitochondria decreased significantly,the distribution of mitochondria tended to be scattered and the mitochondria was formed by malformed mitochondria and autophagic vesicles with the increase level of AZS.The results of immunofluorescence and western blot indicated that there is a different distribution of mitochondria and the level of autophagy in the sperm among the different groups,and they have the characteristics of co-localization and both of them correlated negatively with the level of AZS(P < 0.05).Conclusions1.Mitochondrial autophagy is an active process in human sperm.The activation of autophagy plays an active role in human sperm physiological activities,maintaining and regulating sperm motility.2.Mitochondrial autophagy plays different roles in different level of AZS.When the level of AZS reaches a certain level,resulting uncontrolled regulation on sperm motility by mitochondrial autophagy,the sperm motility decreased in a collapsed manner.