Evaluation of poly(ADP-ribose) polymerase cleavage (cPARP) in ejaculated human sperm fractions after induction of apoptosis

Objective: To examine the presence of cleaved poly(ADP-ribose) polymerase(s) (cPARP) in ejaculated spermatozoa and determine cPARP levels following exposure to chemical or oxidative stress. Design: Prospective pilot study. Setting: Tertiary care academic hospital. Patient(s): Eight healthy men. Intervention(s): Semen specimens were collected, prepared with double-density-gradient centrifugation, and divided into control, hydrogen peroxide (H2O2), H2O2 + 3-aminobenzamide (3-ABA), staurosporine (STS), and STS + 3-ABA treated groups. Main Outcome Measure(s): Cleaved PARP and apoptosis markers by flow cytometry. Result(s): Cleaved PARP was detected in both neat and mature fractions. The cPARP levels were similar in both mature and immature spermatozoa. In combined mature and immature fractions, a higher percentage of late apoptotic sperm was seen in STS + 3-ABA versus STS. Higher levels of late apoptotic spermatozoa were seen in immature versus mature fractions within STS and STS + 3-ABA groups. Lower levels of cPARP were seen in immature versus mature fractions in H2O2, and H2O2 + 3-ABA treated groups. Cleaved PARP was related to activated caspase-3. Conclusion(s): Cleaved PARP is present in ejaculated human spermatozoa. Poly(ADP-ribose) polymerase inhibitors may play a different role in chemical versus oxidative stress-induced sperm damage. (Fertil Steril (R) 2009;91:2210-20. (C) 2009 by American Society for Reproductive Medicine.)