Relationship between phospholipase C zeta immunoreactivity and DNA fragmentation and oxidation in human sperm

OBJECTIVE The study aimed to evaluate the feasibility and reproducibility of measuring phospholipase C zeta (PLCζ) using immunostaining in human sperm and to investigate the relationship between PLCζ immunoreactivity and DNA fragmentation and oxidation in human sperm. METHODS Semen samples were obtained from participants (n=44) and processed by the conventional swim-up method. Sperm concentration, motility, normal form by strict morphology, DNA fragmentation index assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling method and immunofluorescent expression for 8-hydroxy-2'-deoxyguanosine (8-OHdG) and PLCζ were assessed. RESULTS When duplicate PLCζ tests were performed on two sperm samples from each of the 44 participants, similar results were obtained (74.1±9.4% vs. 75.4±9.7%). Two measurements of PLCζ were found to be highly correlated with each other (r=0.759, P<0.001). Immunoreactivity of PLCζ was not associated with donor's age, sperm concentration, motility, and the percentage of normal form as well as DNA fragmentation index. However, immunoreactivity of PLCζ showed a significant negative relationship with 8-OHdG immunoreactivity (r=-0.404, P=0.009). CONCLUSION Measurement of PLCζ by immunostaining is feasible and reproducible. Lower expression of PLCζ in human sperm may be associated with higher sperm DNA oxidation status.