Effects of extracellular adenosine 5 '-triphosphate on human sperm motility
ABSTRACT Extracellular adenosine 5'-triphosphate (ATP) previously has been shown to increase the fertilization percentage in human in vitro fertilization (IVF) performed for male factor infertility. The objective of this study is to determine the effects of extracellular adenosine 5'-triphosphate (ATPe) on human sperm function by examining its effects on end points of sperm capacitation. Sperm obtained from healthy volunteers with normal semen parameters, asthenozoospermic men, and cryopreserved samples were incubated in medium with or without 2.5 mM ATPe. The effects of ATPe on acrosomal exocytosis, protein tyrosine phosphorylation, and sperm motility parameters were quantified. Although ATPe did not affect acrosomal exocytosis or protein tyrosine phosphorylation in sperm from healthy donors, it significantly altered several motility parameters, with the largest effects manifested in increased curvilinear velocity and percentage hyperactivation. ATPe similarly affected sperm selected for poor motility and thawed cryopreserved sperm but to a lesser extent than its effects on sperm with normal motility. ATPe increased straight-line velocity and linearity of sperm obtained from asthenozoospermic men. Human sperm motility characteristics are altered by ATPe; this finding may explain its previously reported beneficial effect on human IVF. These results suggest that ATPe could constitute a new therapeutic modality in the treatment of male infertility.
SourceAvailable from: Gilles Kauffenstein[Show abstract] [Hide abstract]
ABSTRACT: In this work we report that Entpd1-/- mice, deficient for the ectonucleotidase nucleoside triphosphate diphosphohydrolase-1 (NTPDase1), produce smaller litters (27% reduction) compared to wild type C57BL6 animals. This deficit is linked to reduced in vivo oocytes fertilization by Entpd1-/- males (61±11% vs. 88±7% for Entpd1+/+). Normal epididymal sperm count, spermatozoa morphology, capacitation and motility and reduced ejaculated sperm number (2.4±0.5 vs. 3.7±0.4 million for Entpd1+/+) pointed on vas deferens dysfunction. NTPDase1 was localized by immunofluorescence in the tunica muscularis of vas deferens. Its absence resulted in a major ATP hydrolysis deficiency as observed in situ by histochemistry and in primary smooth muscle cell cultures. In vitro, Entpd1-/- vas deferens displayed an exacerbated contraction to ATP, a diminished response to its non-hydrolysable analogue abMeATP, and a reduced contraction to electrical field stimulation suggesting an altered P2X1 receptor function with a propensity to desensitize. This functional alteration was accompanied with a 3-fold decrease in P2X1 protein expression in Entpd1-/- vas deferens with no variation in mRNA levels. Accordingly, exogenous nucleotidase activity was required to fully preserve P2X1 receptor activation by ATP in vitro. Our study demonstrates that NTPDase1 is required to maintain normal P2X1 receptor functionality in vas deferens and that its absence leads to impaired peristalsis, reduced spermatozoa concentration in the semen, and eventually reduced fertility. This suggests that alteration of NTPDase1 activity impacts on ejaculation efficacy and male fertility. This work may contribute to unveil causes of infertility and open new therapeutic potentials.Journal of Biological Chemistry 08/2014; 289(41). DOI:10.1074/jbc.M114.604082 · 4.60 Impact Factor
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ABSTRACT: There are multiple roles for purinergic signalling in both male and female reproductive organs. ATP, released as a cotransmitter with noradrenaline from sympathetic nerves, contracts smooth muscle via P2X1 receptors in vas deferens, seminal vesicles, prostate and uterus, as well as in blood vessels. Male infertility occurs in P2X1 receptor knockout mice. Both short- and long-term trophic purinergic signalling occurs in reproductive organs. Purinergic signalling is involved in hormone secretion, penile erection, sperm motility and capacitation, and mucous production. Changes in purinoceptor expression occur in pathophysiological conditions, including pre-eclampsia, cancer and pain.Purinergic Signalling 11/2013; 10(1). DOI:10.1007/s11302-013-9399-7 · 3.51 Impact Factor
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ABSTRACT: Ubiquinol-cytochrome-c reductase core protein 2 (UQCRC2) is a component of ubiquinol-cytochrome c reductase complex that is known to correlate with male fertility via spermatogenesis. Simultaneously, nutlin-3a is a small molecule antagonist of mouse double minute 2 repressor (MDM2), activate p53 and induce apoptosis responsible for spermatogenesis. To date, however there are no known effects of nutlin-3a on reproduction. Therefore, present study was designed to investigate the effect of nutlin-3a on male fertility via UQCRC2. In this in vitro trial with mice spermatozoa, we utilized CASA, CTC staining, ATP assay, western blotting, and IVF to measure the main study outcome. The short-term exposure of spermatozoa in nutlin-3a decreases sperm motion kinematics, intracellular ATP production, capacitation, the acrosome reaction, UQCRC2, and tyrosine phosphorylation (TYP) of sperm proteins in a dose-dependent manner. Notably, the decreased UQCRC2 and TYP were associated with reduced sperm kinematics, ATP production, and capacitation, which ultimately led to adverse effects on male fertility such as poor fertilization rates and embryo development. Thus, nutlin-3a may be considered as a potential male contraceptive agent due to its ability to decrease fertility secondary to changes in overall sperm physiology and embryonic development. However, the results of this preliminary study have to be confirmed by additional independent trial.PLoS ONE 10/2013; 8(10):e76959. DOI:10.1371/journal.pone.0076959 · 3.53 Impact Factor