Cyclic nucleotide phosphodiesterases in human spermatozoa and seminal fluid: Presence of an active PDE10A in human spermatozoa.
Cyclic adenosine monophosphate (cAMP) plays a crucial role as a signaling molecule for sperm functions such as capacitation, motility and acrosome reaction. It is well known that cAMP degradation by phosphodiesterase (PDE) enzyme has a major impact on sperm functions. The present study was undertaken to characterize cAMP-PDE activity in human semen.



cAMP-PDE activity was measured in human sperm and seminal plasma using family specific PDE inhibitors. Three sperm fractionation methods were applied to assess cAMP-PDE activity in spermatozoa. Western blots were used to validate the presence of specific family in sperm and seminal plasma.



Using three sperm fractionation methods, we demonstrated that in human sperm, the major cAMP-PDE activity is papaverine-sensitive and thus ascribed to PDE10. In seminal plasma, total cAMP-PDE activity was 1.14±0.39fmol of cAMP hydrolyzed per minute per μg of protein. Using specific inhibitors, we showed that the major cAMP-PDE activity found in human seminal plasma is ascribed to PDE4 and PDE11. Western blot analysis, immunoprecipitation with a specific monoclonal antibody, and mass spectrometry confirmed the presence of PDE10 in human spermatozoa.



This study provides the first demonstration of the presence of functional PDE10 in human spermatozoa and functional PDE4 and PDE11 in human seminal plasma.



Since the contribution of cyclic nucleotides in several sperm functions is well known, the finding that PDE10 is an active enzyme in human spermatozoa is novel and may lead to new insight into fertility.
Centre de recherche en reproduction, développement et santé intergénérationnelle, Département d'obstétrique, gynécologie et reproduction, Centre de recherche du CHU de Québec-Université Laval, 2705 Boul. Laurier, Québec G1V 4G2, Canada.
Loïze
L
Maréchal
Centre de recherche en reproduction, développement et santé intergénérationnelle, Département des Sciences Animales, Faculté des sciences de l'agriculture et de l'alimentation, Université Laval, Québec G1V 0A6, Québec, Canada.
Christine
C
Guillemette
Centre de recherche en reproduction, développement et santé intergénérationnelle, Département d'obstétrique, gynécologie et reproduction, Centre de recherche du CHU de Québec-Université Laval, 2705 Boul. Laurier, Québec G1V 4G2, Canada.
Serge
S
Goupil
L'Alliance Boviteq Inc, 19320 Grand rang St-François, Saint-Hyacinthe, Québec J2T 5H1, Canada.
Patrick
P
Blondin
Centre de recherche en reproduction, développement et santé intergénérationnelle, Département d'obstétrique, gynécologie et reproduction, Centre de recherche du CHU de Québec-Université Laval, 2705 Boul. Laurier, Québec G1V 4G2, Canada.
Pierre
P
Leclerc
Centre de recherche en reproduction, développement et santé intergénérationnelle, Département des Sciences Animales, Faculté des sciences de l'agriculture et de l'alimentation, Université Laval, Québec G1V 0A6, Québec, Canada. Electronic address: Francois.Richard@fsaa.ulaval.ca.
François J
FJ
Richard
D020101:Acrosome Reaction / Q000187:drug effects / Q000502:physiology; D000595:Amino Acid Sequence; D001826:Body Fluids / Q000187:drug effects / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism*; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4 / Q000378:metabolism; D006801:Humans; D008297:Male; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D012661:Semen / Q000187:drug effects / Q000378:metabolism*; D016415:Sequence Alignment; D013075:Sperm Capacitation / Q000187:drug effects / Q000502:physiology; D013081:Sperm Motility / Q000187:drug effects / Q000502:physiology; D013094:Spermatozoa / Q000187:drug effects / Q000378:metabolism*
D010726:Phosphodiesterase Inhibitors; D000242:Cyclic AMP; C119843:PDE10A protein, human; D010727:Phosphoric Diester Hydrolases; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4
Phosphodiesterase; Seminal plasma; Spermatozoa