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Redox regulation of mammalian sperm capacitation.

O'Flaherty C - Asian J. Androl. (2015 Jul-Aug)

Bottom Line: Both, oxidation of thiols forming disulfide bridges and the increase on thiol content are necessary to regulate different sperm proteins associated with capacitation.Reducing equivalents such as NADH and NADPH are necessary to support capacitation in many species including humans.The dysregulation of PRDXs and of enzymes needed for their reactivation such as thioredoxin/thioredoxin reductase system and glutathione-S-transferases impairs sperm motility, capacitation, and promotes DNA damage in spermatozoa leading to male infertility.

View Article: PubMed Central - PubMed

Affiliation: Urology Research Laboratory, Surgery Department (Urology Division), Faculty of Medicine, McGill University; The Research Institute, McGill University Health Centre, Montréal, Québec, Canada.

ABSTRACT
Capacitation is a series of morphological and metabolic changes necessary for the spermatozoon to achieve fertilizing ability. One of the earlier happenings during mammalian sperm capacitation is the production of reactive oxygen species (ROS) that will trigger and regulate a series of events including protein phosphorylation, in a time-dependent fashion. The identity of the sperm oxidase responsible for the production of ROS involved in capacitation is still elusive, and several candidates are discussed in this review. Interestingly, ROS-induced ROS formation has been described during human sperm capacitation. Redox signaling during capacitation is associated with changes in thiol groups of proteins located on the plasma membrane and subcellular compartments of the spermatozoon. Both, oxidation of thiols forming disulfide bridges and the increase on thiol content are necessary to regulate different sperm proteins associated with capacitation. Reducing equivalents such as NADH and NADPH are necessary to support capacitation in many species including humans. Lactate dehydrogenase, glucose-6-phospohate dehydrogenase, and isocitrate dehydrogenase are responsible in supplying NAD (P) H for sperm capacitation. Peroxiredoxins (PRDXs) are newly described enzymes with antioxidant properties that can protect mammalian spermatozoa; however, they are also candidates for assuring the regulation of redox signaling required for sperm capacitation. The dysregulation of PRDXs and of enzymes needed for their reactivation such as thioredoxin/thioredoxin reductase system and glutathione-S-transferases impairs sperm motility, capacitation, and promotes DNA damage in spermatozoa leading to male infertility.

No MeSH data available.


Related in: MedlinePlus

Inhibition of PRDXs and human sperm capacitation. Percoll density gradient-selected spermatozoa were incubated in BWW medium supplemented with FCSu for 4 h at 37°C in the presence or absence of TSP or MJ33, inhibitors of the 2-Cys PRDXs and of Ca2+-independent phospholipase A2 activity of PRDX6. At the end of the treatment, sperm proteins were supplemented with sample buffer containing dithiothreitol, electrophoresed and blotted with a mouse monoclonal anti-phosphotyrosine antibody (clone 4G10)(Upstate Biotechnology, Inc., (Lake Placid, NY, USA) and with an anti-tubulin antibody as a loading control. All samples are from the same gel. Blots are representative of three separate experiments using semen samples from different healthy donors. FCSu: fetal cord serum ultrafiltrate; TSP: thiostrepton; PRDXs: peroxiredoxins.
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Figure 5: Inhibition of PRDXs and human sperm capacitation. Percoll density gradient-selected spermatozoa were incubated in BWW medium supplemented with FCSu for 4 h at 37°C in the presence or absence of TSP or MJ33, inhibitors of the 2-Cys PRDXs and of Ca2+-independent phospholipase A2 activity of PRDX6. At the end of the treatment, sperm proteins were supplemented with sample buffer containing dithiothreitol, electrophoresed and blotted with a mouse monoclonal anti-phosphotyrosine antibody (clone 4G10)(Upstate Biotechnology, Inc., (Lake Placid, NY, USA) and with an anti-tubulin antibody as a loading control. All samples are from the same gel. Blots are representative of three separate experiments using semen samples from different healthy donors. FCSu: fetal cord serum ultrafiltrate; TSP: thiostrepton; PRDXs: peroxiredoxins.

Mentions: The PRDX family members are attractive candidates in regulating the levels of ROS for physiological functions because of their abundance and strategic localizations.8687 Human spermatozoa incubated under capacitating conditions with fetal cord serum ultrafiltrate in the presence of thiostrepton, an inhibitor of 2-Cys PRDXs,107 showed reduced levels of tyrosine phosphorylation in a dose-dependent manner compared with controls in the absence of the inhibitor (Figure 5). These results indicate the need for active 2-Cys PRDXs to assure tyrosine phosphorylation during capacitation, possibly by regulating ROS action.


Redox regulation of mammalian sperm capacitation.

O'Flaherty C - Asian J. Androl. (2015 Jul-Aug)

Inhibition of PRDXs and human sperm capacitation. Percoll density gradient-selected spermatozoa were incubated in BWW medium supplemented with FCSu for 4 h at 37°C in the presence or absence of TSP or MJ33, inhibitors of the 2-Cys PRDXs and of Ca2+-independent phospholipase A2 activity of PRDX6. At the end of the treatment, sperm proteins were supplemented with sample buffer containing dithiothreitol, electrophoresed and blotted with a mouse monoclonal anti-phosphotyrosine antibody (clone 4G10)(Upstate Biotechnology, Inc., (Lake Placid, NY, USA) and with an anti-tubulin antibody as a loading control. All samples are from the same gel. Blots are representative of three separate experiments using semen samples from different healthy donors. FCSu: fetal cord serum ultrafiltrate; TSP: thiostrepton; PRDXs: peroxiredoxins.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492048&req=5

Figure 5: Inhibition of PRDXs and human sperm capacitation. Percoll density gradient-selected spermatozoa were incubated in BWW medium supplemented with FCSu for 4 h at 37°C in the presence or absence of TSP or MJ33, inhibitors of the 2-Cys PRDXs and of Ca2+-independent phospholipase A2 activity of PRDX6. At the end of the treatment, sperm proteins were supplemented with sample buffer containing dithiothreitol, electrophoresed and blotted with a mouse monoclonal anti-phosphotyrosine antibody (clone 4G10)(Upstate Biotechnology, Inc., (Lake Placid, NY, USA) and with an anti-tubulin antibody as a loading control. All samples are from the same gel. Blots are representative of three separate experiments using semen samples from different healthy donors. FCSu: fetal cord serum ultrafiltrate; TSP: thiostrepton; PRDXs: peroxiredoxins.
Mentions: The PRDX family members are attractive candidates in regulating the levels of ROS for physiological functions because of their abundance and strategic localizations.8687 Human spermatozoa incubated under capacitating conditions with fetal cord serum ultrafiltrate in the presence of thiostrepton, an inhibitor of 2-Cys PRDXs,107 showed reduced levels of tyrosine phosphorylation in a dose-dependent manner compared with controls in the absence of the inhibitor (Figure 5). These results indicate the need for active 2-Cys PRDXs to assure tyrosine phosphorylation during capacitation, possibly by regulating ROS action.

Bottom Line: Both, oxidation of thiols forming disulfide bridges and the increase on thiol content are necessary to regulate different sperm proteins associated with capacitation.Reducing equivalents such as NADH and NADPH are necessary to support capacitation in many species including humans.The dysregulation of PRDXs and of enzymes needed for their reactivation such as thioredoxin/thioredoxin reductase system and glutathione-S-transferases impairs sperm motility, capacitation, and promotes DNA damage in spermatozoa leading to male infertility.

View Article: PubMed Central - PubMed

Affiliation: Urology Research Laboratory, Surgery Department (Urology Division), Faculty of Medicine, McGill University; The Research Institute, McGill University Health Centre, Montréal, Québec, Canada.

ABSTRACT
Capacitation is a series of morphological and metabolic changes necessary for the spermatozoon to achieve fertilizing ability. One of the earlier happenings during mammalian sperm capacitation is the production of reactive oxygen species (ROS) that will trigger and regulate a series of events including protein phosphorylation, in a time-dependent fashion. The identity of the sperm oxidase responsible for the production of ROS involved in capacitation is still elusive, and several candidates are discussed in this review. Interestingly, ROS-induced ROS formation has been described during human sperm capacitation. Redox signaling during capacitation is associated with changes in thiol groups of proteins located on the plasma membrane and subcellular compartments of the spermatozoon. Both, oxidation of thiols forming disulfide bridges and the increase on thiol content are necessary to regulate different sperm proteins associated with capacitation. Reducing equivalents such as NADH and NADPH are necessary to support capacitation in many species including humans. Lactate dehydrogenase, glucose-6-phospohate dehydrogenase, and isocitrate dehydrogenase are responsible in supplying NAD (P) H for sperm capacitation. Peroxiredoxins (PRDXs) are newly described enzymes with antioxidant properties that can protect mammalian spermatozoa; however, they are also candidates for assuring the regulation of redox signaling required for sperm capacitation. The dysregulation of PRDXs and of enzymes needed for their reactivation such as thioredoxin/thioredoxin reductase system and glutathione-S-transferases impairs sperm motility, capacitation, and promotes DNA damage in spermatozoa leading to male infertility.

No MeSH data available.


Related in: MedlinePlus