Supplementation of cryopreservation medium with TAT-Peroxiredoxin 2 fusion protein improves human sperm quality and function.

OBJECTIVE: To investigate the potential effects of TAT-PRDX2 protein supplementation to the cryopreservation medium on post-thaw sperm quality and function. DESIGN: In vitro prospective study. SETTING: Medical university hospital. PATIENT(S): Fifty normozoospermic, 50 asthenozoospermic, and 50 oligoasthenozoospermic men undergoing semen analysis for couple infertility. INTERVENTION(S): Each semen sample was divided into three aliquots: fresh, cryopreserved control (without additive), and cryopreserved with TAT-PRDX2 protein. MAIN OUTCOME MEASURE(S): Sperm motility, viability, mitochondrial potential, and DNA damage as well as reactive oxygen species (ROS) levels and lipid peroxidation were analyzed. Acrosome reaction and zona-free hamster oocyte penetration tests were performed to assess the fertilization ability of cryopreserved spermatozoa. RESULT(S): In normozoospermic and asthenozoospermic groups, the addition of 150 µg/mL TAT-PRDX2 significantly reduced intracellular ROS and malondialdehyde levels and enhanced post-thaw sperm motility and viability when compared with the cryopreserved control of the respective groups but did not produce any significant protective effect in the oligoasthenozoospermic group. Mitochondrial potential was significantly increased, whereas DNA fragmentation was significantly decreased, after TAT-PRDX2 supplementation only in the asthenozoospermic group when compared with the cryopreserved control. Although the penetration rate and the penetration index were not markedly improved, TAT-PRDX2 supplementation obviously reduced spontaneous acrosome reaction and increased calcium ionophore-induced acrosome reaction in the normozoospermic and asthenozoospermic groups. CONCLUSION(S): TAT-PRDX2 protein effectively exerted cryoprotective effects on spermatozoa by reducing intracellular ROS level and thereby improved post-thaw sperm quality and function, especially for asthenozoospermic samples. TAT-PRDX2 protein is a promising additive for developing a new and highly efficient semen cryoprotectant.

Papain-Based Vaccination Modulates Schistosoma mansoni Infection-Induced Cytokine Signals.

We have previously shown that immunization of outbred rodents with cysteine peptidases-based vaccine elicited type 2-biased immune responses associated with consistent and reproducible protection against challenge Schistosoma mansoni. We herein start to elucidate the molecular basis of C57BL/6 mouse resistance to S. mansoni following treatment with the cysteine peptidase, papain. We evaluated the early cytokine signals delivered by epidermal, dermal, and draining lymph node cells of naïve, and S. mansoni -infected mice treated 1 day earlier with 0 or 50 µg papain, or immunized twice with papain only (10 µg/mouse), papain-free recombinant S. mansoni glyceraldehyde 3-phosphate dehydrogenase and 2-Cys peroxiredoxin peptide (10 and 15 µg/mouse, respectively = antigen Mix), or papain-adjuvanted antigen Mix. Schistosoma mansoni infection induced epidermal and lymph node cells to release type 1, type 2 and type 17 cytokines, known to counteract each other. Expectedly, humoral immune responses were negligible until patency. Papain pretreatment or papain-based vaccination diminished or shut off S. mansoni infection early induction of type 1, type 17 and type 2 cytokines except for thymic stromal lymphopoietin and programmed the immune system towards a polarized type 2 immune milieu, associated with highly significant (P < 0.005 - <0.0001) resistance to S. mansoni infection.

Repeated administration of PEP-1-Cu,Zn-superoxide dismutase and PEP-1-peroxiredoxin-2 to senescent mice induced by D-galactose improves the hippocampal functions.

Oxidative stress initiates age-related reduction in hippocampal neurogenesis and the use of antioxidants has been proposed as an effective strategy to prevent or attenuate the reduction of neurogenesis in the hippocampus. In the present study, we investigated the effects of Cu,Zn-superoxide dismutase (SOD1) and/or peroxiredoxin-2 (PRX2) on cell proliferation and neuroblast differentiation in the dentate gyrus in a model of D-galactose-induced aging model. For this study, we constructed an expression vector, PEP-1, fused PEP-1 with SOD1 or PRX2, and generated PEP-1-SOD1 and PEP-1-PRX2 fusion protein. The aging model was induced by subcutaneous injection of D-galactose (100 mg/kg) to 6-week-old male mice for 10 weeks. PEP-1, PEP-1-SOD1 and/or PEP-1-PRX2 fusion protein was intraperitoneally administered to these mice at 13-week-old once a day for 3 weeks and sacrificed at 30 min after the last administrations. The administration of PEP-1-SOD1 and/or PEP-1-PRX2 significantly improved D-galactose-induced deficits on the escape latency, swimming speeds, platform crossings, spatial preference for the target quadrant in Morris water maze test. In addition, the administration of PEP-1-SOD1 and/or PEP-1-PRX2 ameliorated D-galactose-induced reductions of cell proliferation and neuroblast differentiation in the dentate gyrus and significantly reduced D-galactose-induced lipid peroxidation in the hippocampus. These effects were more prominent in the PEP-1-SOD1-treated group with PEP-1-PRX2. These results suggest that a SOD1 and/or PRX2 supplement to aged mice could improve the memory deficits, cell proliferation and neuroblast differentiation in the dentate gyrus of D-galactose induced aged mice by reducing lipid peroxidation.

[Modified peroxiredoxins as prototypes of drugs a powerful antioxidant].

The possibility of using modified peroxyredoxins as powerful antioxidant agents has been considered. Peroxyredoxins immobilized on perfluorocarbon emulsions and PTD-modified peroxyredoxins have been studied. It has been shown that peroxyredoxins efficiently bind to particles of perfluorocarbon emulsions, while maintaining their antioxidant properties. A panel of PTD-modified peroxyredoxins has been created and peroxyredoxins most effective both in antioxidant properties and the ability to penetrate cells have been selected. The modified peroxyredoxins obtained may serve as the basis for the design of drug with powerful antioxidant action.

TAT-mediated peroxiredoxin 5 and 6 protein transduction protects against high-glucose-induced cytotoxicity in retinal pericytes.

AIMS: Hyperglycemia-induced oxidative stress is implicated in pericyte apoptosis seen in diabetic retinopathy. The six mammalian Peroxiredoxins (PRDXs) comprise a novel family of antioxidative proteins that negatively regulate oxidative stress-induced apoptosis by controlling reactive oxygen species (ROS) levels. MAIN METHODS: Sprague-Dawley rats were used to detect the retinal expressions of PRDXs1-6. Pig pericytes cultured in high-glucose medium were used to monitor the protective effect of PRDX5 and 6 against high-glucose-associated change. Recombinant PRDX5 and 6 proteins were linked to the Trans-Activating Transduction (TAT) domain from HIV-1 TAT protein for their efficient delivery into cells/tissues. KEY FINDINGS: We found higher expression of PRDX5 and 6 mRNAs and PRDX5 and 6 proteins in retina than the other Prdxs (Prdx1-4). Western blotting affirmed the intracellular presence of TAT-linked proteins and revealed the efficient transduction of TAT-HA-PRDX5 and 6 in these cells. Extrinsic supply of TAT-HA-PRDX5 and 6 proteins inhibited the oxidative stress-induced DNA damage after high-glucose exposure in pig pericytes. The cell survival and apoptosis assay revealed that extrinsic supply of TAT-HA-PRDX5 and 6 proteins was responsible for inhibiting hyperglycemia-induced pericyte apoptosis. SIGNIFICANCE: Results suggest that delivery of PRDX5 and 6 might protect hyperglycemia-induced pericyte loss to inhibit oxidative stress.