TAT-peroxiredoxin 2 Fusion Protein Supplementation Improves Sperm Motility and DNA Integrity in Sperm Samples from Asthenozoospermic Men.

We compared levels of peroxiredoxin 2 in semen samples from normozoospermic and asthenozoospermic men. The potential effects of TAT-peroxiredoxin 2 fusion protein on sperm motility and DNA integrity were also evaluated. Semen samples were obtained from 50 normozoospermic and 50 asthenozoospermic men. Lipid peroxidation of semen was determined using a commercial malondialdehyde kit. Sperm DNA fragmentation was evaluated by TUNEL assay. Western blot and immunofluorescence were performed to detect the amount of peroxiredoxin 2 protein in seminal plasma and spermatozoa. Sperm motility, DNA damage and levels of reactive oxygen species were evaluated after TAT-peroxiredoxin 2 fusion protein supplementation to the sperm suspension for 2 and 12 hours of incubation. In asthenozoospermic semen samples a significantly higher level of malondialdehyde and DNA damage was discovered. However, the expression of peroxiredoxin 2 was significantly lower in seminal plasma and spermatozoa compared with that of normozoospermic men. TAT-peroxiredoxin 2 fusion protein was successfully prepared and delivered to the spermatozoa. Interestingly adding TAT-peroxiredoxin 2 in asthenozoospermic sperm suspension effectively defended against the decrease in progressive motility and the increase in DNA damage. This study shows that supplementation of TAT-peroxiredoxin 2 fusion protein in the sperm suspension from asthenozoospermic men effectively improved sperm motility and DNA integrity by reducing levels of reactive oxygen species. Therefore, we speculate that peroxiredoxin 2 may have an important role as an antioxidant defense in semen and would provide new prevention and therapy alternatives for asthenozoospermia.