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

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 Angiotensin II-induced protein tyrosine phosphorylation in neonatal rat cardiac fibroblasts.

1994 ◽  
Vol 269 (30) ◽  
pp. 19626-19632
Author(s):  
W. Schorb ◽  
T.C. Peeler ◽  
N.N. Madigan ◽  
K.M. Conrad ◽  
K.M. Baker
Keyword(s):  
Angiotensin Ii ◽  
Tyrosine Phosphorylation ◽  
Cardiac Fibroblasts ◽  
Neonatal Rat ◽  
Protein Tyrosine Phosphorylation ◽  
Protein Tyrosine
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