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Redox regulation of mammalian sperm capacitation.

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

Bottom Line: Redox signaling during capacitation is associated with changes in thiol groups of proteins located on the plasma membrane and subcellular compartments of the spermatozoon.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.

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

Sources of NAD(P)H for production of ROS during bovine sperm capacitation. The physiological inducer heparin promotes activation of the sperm oxidase in bull spermatozoa. The ICDHcyt and of LDH-C4cyt supply NADPH and NADH necessary for producing ROS. ROS: reactive oxygen species; ICDHcyt: cytosolic isoforms of isocitrate dehydrogenase; LDH-C4cyt: cytosolic lactate dehydrogenase C4.
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Figure 4: Sources of NAD(P)H for production of ROS during bovine sperm capacitation. The physiological inducer heparin promotes activation of the sperm oxidase in bull spermatozoa. The ICDHcyt and of LDH-C4cyt supply NADPH and NADH necessary for producing ROS. ROS: reactive oxygen species; ICDHcyt: cytosolic isoforms of isocitrate dehydrogenase; LDH-C4cyt: cytosolic lactate dehydrogenase C4.

Mentions: The in vivo supply of NADPH could be accomplished by two different enzymes: glucose 6-phosphate dehydrogenase (G6PDH) and isocitrate dehydrogenase (ICDH) (Figure 4). Both enzymes are present in the cytosol of spermatozoa; however, their presence will vary depending on the species under study. For instance, G6PDH is present in human7273 but absent in bull spermatozoa.7074 The presence of ICDH activity was found in bull spermatozoa and its inhibitor, oxalomalate, prevented sperm capacitation, suggesting an important role for this dehydrogenase to activate bull spermatozoa.70 Proteomics studies by different laboratories also confirmed the presence of ICDH in human spermatozoa;567576 whether the ICDH is involved in human sperm capacitation remains unknown.


Redox regulation of mammalian sperm capacitation.

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

Sources of NAD(P)H for production of ROS during bovine sperm capacitation. The physiological inducer heparin promotes activation of the sperm oxidase in bull spermatozoa. The ICDHcyt and of LDH-C4cyt supply NADPH and NADH necessary for producing ROS. ROS: reactive oxygen species; ICDHcyt: cytosolic isoforms of isocitrate dehydrogenase; LDH-C4cyt: cytosolic lactate dehydrogenase C4.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 4: Sources of NAD(P)H for production of ROS during bovine sperm capacitation. The physiological inducer heparin promotes activation of the sperm oxidase in bull spermatozoa. The ICDHcyt and of LDH-C4cyt supply NADPH and NADH necessary for producing ROS. ROS: reactive oxygen species; ICDHcyt: cytosolic isoforms of isocitrate dehydrogenase; LDH-C4cyt: cytosolic lactate dehydrogenase C4.
Mentions: The in vivo supply of NADPH could be accomplished by two different enzymes: glucose 6-phosphate dehydrogenase (G6PDH) and isocitrate dehydrogenase (ICDH) (Figure 4). Both enzymes are present in the cytosol of spermatozoa; however, their presence will vary depending on the species under study. For instance, G6PDH is present in human7273 but absent in bull spermatozoa.7074 The presence of ICDH activity was found in bull spermatozoa and its inhibitor, oxalomalate, prevented sperm capacitation, suggesting an important role for this dehydrogenase to activate bull spermatozoa.70 Proteomics studies by different laboratories also confirmed the presence of ICDH in human spermatozoa;567576 whether the ICDH is involved in human sperm capacitation remains unknown.

Bottom Line: Redox signaling during capacitation is associated with changes in thiol groups of proteins located on the plasma membrane and subcellular compartments of the spermatozoon.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.

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