scholarly journals Capacitation-associated protein tyrosine phosphorylation and membrane fluidity changes are impaired in the spermatozoa of asthenozoospermic patients

Reproduction ◽  
2005 ◽  
Vol 129 (6) ◽  
pp. 697-705 ◽  
Author(s):  
Mariano G Buffone ◽  
Juan C Calamera ◽  
Sandra V Verstraeten ◽  
Gustavo F Doncel
Keyword(s):  
Membrane Fluidity ◽  
Tyrosine Phosphorylation ◽  
Plasma Membranes ◽  
Phosphodiesterase Inhibitor ◽  
Human Sperm ◽  
Computer Assisted ◽  
Protein Tyrosine Phosphorylation ◽  
Membrane Composition ◽  
Protein Tyrosine ◽  
Camp Analog

Sperm protein tyrosine phosphorylation has been associated with capacitation, motility changes, zona binding, and fertilizing ability. We previously demonstrated that gradient-isolated human sperm subpopulations differ in their plasma membrane composition, their ability to phosphorylate proteins in tyrosine residues, and their capacity to undergo hyperactivation. In this study, we have characterized capacitation-associated changes in protein tyrosine phosphorylation and membrane fluidity in spermatozoa of asthenozoospermic and normozoospermic patients consulting for infertility. Semen samples were studied at baseline and after a capacitating incubation with or without the addition of a permeable cAMP analog and a phosphodiesterase inhibitor. Basic sperm and computer-assisted motion parameters, hyperactivation, protein tyrosine phosphorylation (immunofluorescence and Western blot), and membrane fluidity (fluorescent Laurdan probe) were the main study parameters. In comparison with normozoospermic and proven-fertile donor semen, asthenozoospermic samples showed lower motility, velocity, and amplitude of lateral head displacement, both originally and after a 6-h capacitating incubation. Unlike those in normal samples, asthenozoospermic spermatozoa were unable to increase protein tyrosine phosphorylation during capacitation. Such impairment, however, was overcome when they were incubated with a membrane-permeable cAMP analog and a phosphodiesterase inhibitor, indicating a possible membrane defect. Confirming this hypothesis, plasma membranes of asthenozoospermic sperm showed decreased fluidity (increased Laurdan polarization), even after a capacitating incubation. In conclusion, spermatozoa from functional asthenozoospermic samples may owe their poor motility, and their inability to properly capacitate and develop hyperactivation, to an impairment in the tyrosine phosphorylation of critical proteins caused by decreased membrane fluidity. These findings suggest a molecular pathogenetic mechanism for a common seminal pathology associated with male infertility.

scholarly journals pH-dependent effects of procaine on equine gamete activation†

2019 ◽  
Vol 101 (5) ◽  
pp. 1056-1074 ◽  
Author(s):  
Bart Leemans ◽  
Tom A E Stout ◽  
Ann Van Soom ◽  
Bart M Gadella
Keyword(s):  
Tyrosine Phosphorylation ◽  
Computer Assisted ◽  
Cell Organelle ◽  
Protein Tyrosine Phosphorylation ◽  
Weak Base ◽  
Cell Organelles ◽  
Protein Tyrosine ◽  
Sperm Analysis ◽  
Ph Dependent ◽  
Camp Levels

Abstract Procaine directly triggers pH-dependent cytokinesis in equine oocytes and induces hypermotility in stallion spermatozoa, an important event during capacitation. However, procaine-induced hyperactivated motility is abolished when sperm is washed to remove the procaine prior to sperm-oocyte co-incubation. To understand how procaine exerts its effects, the external Ca2+ and Na+ and weak base activity dependency of procaine-induced hyperactivation in stallion spermatozoa was assessed using computer-assisted sperm analysis. Percoll-washed stallion spermatozoa exposed to Ca2+-depleted (+2 mM EGTA) procaine-supplemented capacitating medium (CM) still demonstrated hyperactivated motility, whereas CM without NaCl or Na+ did not. Both procaine and NH4Cl, another weak base, were shown to trigger a cytoplasmic pH increase (BCECF-acetoxymethyl (AM)), which is primarily induced by a pH rise in acidic cell organelles (Lysosensor green dnd-189), accompanied by hypermotility in stallion sperm. As for procaine, 25 mM NH4Cl also induced oocyte cytokinesis. Interestingly, hyperactivated motility was reliably induced by 2.5–10 mM procaine, whereas a significant cytoplasmic cAMP increase and tail-associated protein tyrosine phosphorylation were only observed at 10 mM. Moreover, 25 mM NH4Cl did not support the latter capacitation characteristics. Additionally, cAMP levels were more than 10× higher in boar than stallion sperm incubated under similar capacitating conditions. Finally, stallion sperm preincubated with 10 mM procaine did not fertilize equine oocytes. In conclusion, 10 mM procaine causes a cytoplasmic and acidic sperm cell organelle pH rise that simultaneously induces hyperactivated motility, increased levels of cAMP and tail-associated protein tyrosine phosphorylation in stallion spermatozoa. However, procaine-induced hypermotility is independent of the cAMP/protein tyrosine phosphorylation pathway.

Decreased protein tyrosine phosphorylation and membrane fluidity in spermatozoa from infertile men with varicocele

2006 ◽  
Vol 73 (12) ◽  
pp. 1591-1599 ◽  
Author(s):  
M.G. Buffone ◽  
S. Brugo-Olmedo ◽  
J.C. Calamera ◽  
S.V. Verstraeten ◽  
F. Urrutia ◽  
...  
Keyword(s):  
Membrane Fluidity ◽  
Tyrosine Phosphorylation ◽  
Protein Tyrosine Phosphorylation ◽  
Protein Tyrosine ◽  
Infertile Men

Luteinizing hormone modulates intracellular calcium, protein tyrosine phosphorylation and motility during human sperm capacitation

2017 ◽  
Vol 483 (2) ◽  
pp. 834-839 ◽  
Author(s):  
Aideé S. López-Torres ◽  
María E. González-González ◽  
Esperanza Mata-Martínez ◽  
Fernando Larrea ◽  
Claudia L. Treviño ◽  
...  
Keyword(s):  
Luteinizing Hormone ◽  
Intracellular Calcium ◽  
Tyrosine Phosphorylation ◽  
Human Sperm ◽  
Protein Tyrosine Phosphorylation ◽  
Sperm Capacitation ◽  
Protein Tyrosine

scholarly journals Cholecystokinin receptors regulate sperm protein tyrosine phosphorylation via uptake of HCO3−

Reproduction ◽  
2015 ◽  
Vol 150 (4) ◽  
pp. 257-268 ◽  
Author(s):  
Yuchuan Zhou ◽  
Yanfei Ru ◽  
Huijuan Shi ◽  
Yanjiao Wang ◽  
Bin Wu ◽  
...  
Keyword(s):  
Tyrosine Phosphorylation ◽  
Human Sperm ◽  
Peptide Hormone ◽  
Mature Sperm ◽  
Protein Tyrosine Phosphorylation ◽  
Sperm Capacitation ◽  
Protein Tyrosine ◽  
Cck Receptors ◽  
Cck2 Receptor

Cholecystokinin (CCK), a peptide hormone and a neurotransmitter, was detected in mature sperm two decades ago. However, the exact role of CCK and the types of CCK receptors (now termed CCK1 and CCK2) in sperm have not been identified. Here, we find that CCK1 and CCK2 receptors are immunolocalized to the acrosomal region of mature sperm. The antagonist of CCK1 or CCK2 receptor strongly activated the soluble adenylyl cyclase/cAMP/protein kinase A signaling pathway that drives sperm capacitation-associated protein tyrosine phosphorylation in dose- and time-dependent manners. But these actions of stimulation were abolished when sperm were incubated in the medium in the absence of HCO3−. Further investigation demonstrated that the inhibitor of CCK1 or CCK2 receptor could accelerate the uptake of HCO3−and significantly elevate the intracellular pH of sperm. Interestingly, the synthetic octapeptide of CCK (CCK8) showed the same action and mechanism as antagonists of CCK receptors. Moreover, CCK8 and the antagonist of CCK1 or CCK2 receptor were also able to accelerate human sperm capacitation-associated protein tyrosine phosphorylation by stimulating the influx of HCO3−. Thus, the present results suggest that CCK and its receptors may regulate sperm capacitation-associated protein tyrosine phosphorylation by modulating the uptake of HCO3−.

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