Depression currently affects about 280 million people worldwide and its prevalence has been increasing dramatically, especially among the young and people of reproductive age, which consequently leads to an increase in antidepressant consumption. Antidepressants are associated with sexual dysfunction in both men and women; however, their role in male fertility has been scarcely studied. Fluoxetine and sertraline, two serotonin reuptake inhibitors (SSRIs), are among the most prescribed antidepressants worldwide. To determine their possible effects, human sperm cells were exposed to either sertraline or fluoxetine at concentrations previously found in blood and seminal fluid of patients undergoing treatment. Spermatozoa were incubated for up to 24 h at 37°C and 5% CO 2 , and important functional parameters such as sperm motility, viability, mitochondrial membrane potential, cellular reactive oxygen species (ROS) production, chromatin/DNA integrity, acrosome status, and tyrosine phosphorylation were assessed. At low levels, fluoxetine consistently decreased progressive motility throughout time while promoting fluctuations in ROS levels and sperm capacitation. Nevertheless, it did not affect viability, mitochondrial membrane potential, acrosome reaction nor chromatin/DNA integrity. Sertraline, on the other hand, had little to nonsignificant impact at low doses, but affected almost all tested parameters at supratherapeutic concentrations. Altogether, our results suggest that both antidepressants may impair sperm function, possibly through different mechanisms of action, but fluoxetine is the only exhibiting mild negative effects at doses found in vivo .
Humans ; Male ; Spermatozoa/drug effects* ; Fluoxetine/pharmacology* ; Sperm Motility/drug effects* ; Sertraline/pharmacology* ; Reactive Oxygen Species/metabolism* ; Antidepressive Agents/pharmacology* ; Membrane Potential, Mitochondrial/drug effects* ; Sperm Capacitation/drug effects* ; Selective Serotonin Reuptake Inhibitors/pharmacology* ; Cell Survival/drug effects* ; Acrosome Reaction/drug effects*

Prior to fertilization sperm has to undergo an activation process known as capaciation, leading to the acrosome reaction. Till now, little is known about the mechanism for preventing premature capacitation in sperm although decapacitation factors from various sources have been thought to be involved. In this study, we report that NYD-SP27, an isoform of phospholipase C Zeta 1 (PLCZ1), is localized to the sperm acrosome in mouse and human spermatozoa by immunofluorescence using a specific antibody. Western blot and double staining analyses show NYD-SP27 becomes detached from sperm, as they undergo capacitation and acrosome reaction. The absence of HCO3-, a key factor in activating capacitation, from the capacitation-inducing medium prevents the loss of NYD-SP27 from sperm. The anti-NYD-SP27 antibody also prevents the loss of NYD-SP27 from sperm, reduced the number of capacitated sperm, inhibited the acrosome reaction induced by ATP and progesterone, and inhibited agonist-induced PLC-coupled Ca2+ mobilization in sperm, which can be mimicked by the PLC inhibitor, U73122. These data strongly suggest that NYD-SP27 is a physiological inhibitor of PLC that acts as an intrinsic decapacitation factor in sperm to prevent premature capacitation and acrosome reaction.
Acrosome ; drug effects ; metabolism ; Acrosome Reaction ; physiology ; Adult ; Animals ; Calcium ; metabolism ; Fluorescent Antibody Technique, Indirect ; Humans ; Immune Sera ; pharmacology ; Male ; Mice ; Middle Aged ; Phosphoinositide Phospholipase C ; immunology ; metabolism ; Sperm Capacitation ; drug effects ; physiology ; Spermatozoa ; drug effects ; metabolism

OBJECTIVETo investigate the possible involvement of calmodulin in mouse sperm capacitation.

METHODSCalmodulin antagonists W7 at the concentrations of 50, 100 and 200 micromol/L and calmidazolium (CZ) at the concentrations of 10, 20 and 30 micromol/ L, were coincubated with mouse sperm for 2 hours, respectively. The percentage of pattern B sperm was measured by chlorotetracycline staining. Then the sperm were coincubated with 100 micromol/L W7 or 10 micromol/L calmidazolium (CZ) before acrosome reaction was induced by 5 micromol/L progesterone and evaluated by the same method.

RESULTSAfter the treatment of the sperm with different concentrations of CZ or W7, the percentages of pattern B sperm decreased in a dose-dependent manner, significantly different from the control (P < 0.05). There was a statistic difference in the rate of acrosome reaction between the experiment and the control group (P < 0.01).

CONCLUSIONCalmodulin is a key protein involved in mouse sperm capacitation.

Animals ; Calmodulin ; antagonists & inhibitors ; Enzyme Inhibitors ; pharmacology ; Imidazoles ; pharmacology ; Male ; Mice ; Mice, Inbred ICR ; Sperm Capacitation ; drug effects ; Sperm Count ; Sperm Motility ; drug effects ; Spermatids ; cytology ; drug effects ; physiology

AIMTo investigate if the phytoestrogen, genistein, affects essential functions of cryopreserved bovine spermatozoa.

METHODSThe effect of genistein upon motility was assessed by computer-assisted motion analysis. Hemizona assay was performed to detect the ability of spermatozoa binding to the zona pellucida. The inducibility of the acrosome reaction using progesterone and ZP3-6 peptide was analysed by fluorescein-conjugated Pisum sativum agglutinin (FITC-PSA)/Hoechst 33258 double staining. Capacitation after incubation with genistein was assessed by the chlortetracycline (CTC) assay. Immunoblots showed the pattern of protein tyrosine phosphorylation of cryopreserved bovine spermatozoa.

RESULTSImmunodetection of tyrosine-phosphorylated proteins showed that genistein did not affect tyrosine phosphorylation in cryopreserved bovine spermatozoa. However, genistein significantly reduced the progesterone- and ZP3-6 peptide-mediated induction of the acrosome reaction and led to a dose-dependent inhibition of sperm-zona pellucida binding; while sperm motility and capacitation were not affected by this phytoestrogen, as indicated by computer-assisted sperm motion analysis and the CTC assay, respectively.

CONCLUSIONOur results suggest that in cryopreserved bovine spermatozoa, genistein affects a protein tyrosine phosphorylation-independent signal transduction pathway that is involved in sperm capacitation, the acrosome reaction and sperm-zona pellucida binding.

Acrosome Reaction ; drug effects ; physiology ; Animals ; Cattle ; Enzyme Inhibitors ; pharmacology ; Genistein ; pharmacology ; Male ; Protein-Tyrosine Kinases ; antagonists & inhibitors ; Sperm Capacitation ; drug effects ; physiology ; Zona Pellucida ; drug effects ; physiology

OBJECTIVETo study the mechanism of uPA improving sperm capacitation by investigating the effect of uPA on the mitochondrial function of mouse capacitated-sperm in vitro.

METHODSMitochondrial function of mouse capacitated-spermatozoa was evaluated through the assessment of mitochondrial membrane potential using JC-1 performed by flow cytometer and fluorescent microscope respectively. The experiment and the control groups were designed according to the presence or absence of uPA, each divided into 5 subgroups based on the different time of uPA treatment (or BWW in the control groups) at 0, 5, 15, 30 and 60 min respectively.

RESULTS(1) Compared with that at 0 min, the mean fluorescence intensity of JC-1 within the spermatozoal body and the percentage of orange-red colored spermatozoa in the experiment group were increased significantly at 5 and 15 min respectively after uPA incubation (P < 0.05). (2) The mean fluorescence intensity of JC-1 within the spermatozoal body at 15, 30 and 60 min and the percentage of orange-red colored spermatozoa at 5 and 15 min in the group were significantly higher than those in the control group (P < 0.05).

CONCLUSIONuPA could increase the mitochondrial membrane potential of mouse capacitated-spermatozoa in vitro, and maintain it at a high level for a certain period of time. By enhancing sperm mitochondrial function, uPA may provide sufficient energy for capacitated-spermatozoa to increase their motility and change their motor pattern, which might be one of the therapeutic mechanisms of uPA on male infertility.

Animals ; Flow Cytometry ; Fluorescent Dyes ; Male ; Membrane Potential, Mitochondrial ; drug effects ; Mice ; Mice, Inbred Strains ; Sperm Capacitation ; Sperm Motility ; Spermatozoa ; drug effects ; physiology ; Urokinase-Type Plasminogen Activator ; pharmacology

To investigate the function of testis sperm binding protein (TSBP) in sperm capacitation and acrosome reaction, the effect of the recombinant TSBP on the activity of protein kinase A was detected in the transfected cell line. With the use of prokaryotic expressing plasmid pGEX-5X-1/tsbp as template, the novel gene tsbp was amplified by PCR and a eukaryotic expressing vector pcDNA3.1/myc-His(-)B/tsbp was constructed. DNA sequencing and restriction endonuclease digestion analysis indicated that the eukaryotic expression vector pcDNA3.1/myc-His(-)B/tsbp had been constructed successfully. After the recombinant plamid being transfected into HEK293 cells, Western blot verified the expression of tsbp. Fusion protein His6-TSBP was purified from the cell lysate by immobilized metal-ion affinity chromatography (IMAC). Radioautograph revealed a higher PKA activity in the transfected HEK293 cells than in the control group, which indicates that TSBP can increase the activity of PKA.
Acrosome Reaction ; drug effects ; Cell Line ; Cyclic AMP-Dependent Protein Kinases ; drug effects ; Humans ; Male ; Recombinant Proteins ; biosynthesis ; genetics ; pharmacology ; Seminal Plasma Proteins ; biosynthesis ; genetics ; pharmacology ; Sperm Capacitation ; drug effects

OBJECTIVETo explore the effect of nitric oxide (NO) on human sperm capacitation and acrosome reaction (AR).

METHODSDifferent concentrations of sodium nitroprusside (SNP) were added to the sperm suspension from 48 healthy fertile men, and the suspension was incubated in 1 x Earle at 37 degrees C for 1 hour. Progesterone was used to induce AR for 15, 30, 45 and 60 min, and then acid phosphatase (ACP) activity in the suspension before and after capacitation and at different time of AR was measured by p-nitrophenyl sodium phosphate assay. In the meantime, sperm motile parameters were assayed by CASA to observe sperm capacitation and AR.

RESULTSACP activity and sperm motile parameters increased in the 50 approximately 100 nmol/L NO concentration group, showed no significant variation in the 150 approximately 200 nmol/L group, and decreased in the 250 approximately 300 nmol/L group.

CONCLUSIONNO can facilitate sperm capacitation, AR and sperm motile parameters in low concentration and suppress them in high concentration. ACP activity assay of sperm is an objective and reliable method to evaluate sperm capacitation and AR in whole sperm population.

Acid Phosphatase ; metabolism ; Acrosome Reaction ; drug effects ; physiology ; Adult ; Dose-Response Relationship, Drug ; Humans ; Male ; Nitric Oxide ; physiology ; Nitric Oxide Donors ; pharmacology ; Nitroprusside ; pharmacology ; Sperm Capacitation ; drug effects ; physiology ; Sperm Motility ; drug effects ; physiology ; Spermatozoa ; enzymology

Systematical studies are lacking on the influencing factors and mechanisms of the heparin enhanced sperm capacitation, although many studies have shown that heparin enhanced sperm capacitation. The effect of heparin concentration and exposure time, incubation temperature and co-culture with oviductal epithelial cells or cumulus cells on goat sperm capacitation were investigated in this study. The motility, membrane and acrosome integrity and capacitated percentage of goat spermatozoa were assessed after different heparin treatments, and rates of fertilization and embryo cleavage were compared after in vitro insemination of oocytes with spermatozoa capacitated by different heparin treatments. The major results are summarized as follows: 1) When spermatozoa were capacitated with heparin at 5, 10, 25, 50 and 100 microg/mL for 45 min, 50 and 100 microg/mL heparin treatments produced the highest capacitated percentages of 55% and 56%, respectively, but the percentage of spermatozoa with intact acrosomes in the 100 microg/mL heparin treatment decreased significantly (P < 0.05) in comparison with that in the control group, indicating that the optimal heparin concentration for goat sperm capacitation would be 50 microg/mL. 2) Capacitated percentage of spermatozoa increased with extension of treatment time when goat sperm were treated with 50 microg/mL heparin for 0, 10, 20, 30, 45, 60 or 120 min. Although heparin treatments for 45 to 120 min did not differ significantly (P > 0.05) in capacitated sperm percentages, sperm motility and membrane integrity decreased significantly when treated with heparin for 120 min. This suggested that the optimal exposure time of heparin at 50 microg/mL for goat sperm capacitation would be 45 to 60 min. 3) Significantly higher capacitated percentages of spermatozoa were obtained when goat sperm were treated at 42 and 38.5 degrees C than at 15 and 37 degrees C, but sperm motility and acrosome integrity were significantly lower when spermatozoa were treated at 42 degrees C than they were treated at other temperatures. Temperature of 38.5 degrees C would, therefore, be the optimal temperature for goat sperm capacitation. 4) The capacitated percentage of spermatozoa was significantly higher when goat sperm were co-cultured with oviductal epithelial cells than when treated with heparin alone or co-cultured with cumulus cells, but sperm motility and membrane and acrosome integrity did not differ significantly among the three treatments. Rates of fertilization (91.3%) and cleavage (72.2%) were significantly higher in the oviductal epithelial cell co-culture group than those in the heparin alone group. This indicated that co-culture with oviductal epithelial cells significantly enhanced goat sperm capacitation by heparin treatment.
Acrosome Reaction ; drug effects ; physiology ; Animals ; Coculture Techniques ; Epithelial Cells ; cytology ; Fallopian Tubes ; cytology ; Female ; Fertilization in Vitro ; Goats ; Heparin ; pharmacology ; Male ; Sperm Capacitation ; drug effects ; physiology ; Sperm Motility ; Spermatozoa ; cytology ; physiology

Sperm must be capacitated before sperm-ovum fusion. Capacitation was once considered as hyperactivation. But now many investigators thought that capacitation wasn't equal to hyperactivation, and that sperm hyperactivation might be a moiety of capacitation or the result of capacitation. In the present, the methods used to study sperm capacitation include fertilization in vitro, induction of sperm acrosome reaction, FITC-labeled chlortetracycline and plant hemoagglutinin. The studies on sperm capacitation in vitro mainly focused on the inductive substances of sperm capacitation and subsequent results analysis. It could lay foundation for the manifestation of molecular mechanism of sperm capacitation and destination of sperm capacitation in molecular levels.
Adenylyl Cyclases ; physiology ; Bicarbonates ; metabolism ; Calcium ; metabolism ; Humans ; Male ; Phosphorylation ; Sperm Capacitation ; drug effects ; physiology ; Sperm Motility