Effect of seminal plasma on capacitation and hyperactivation in human spermatozoa
134
Citation
44
Reference
10
Related Paper
Citation Trend
Abstract:
While hyperactivated motility is known to be a concomitant of capacitation, and a prerequisite for fertilization, the specific interdependence of capacitation and hyperactivation in human spermatozoa has not been investigated. This study was designed to determine the effect of seminal plasma contamination on the expression of hyperactivated motility and the relationship between hyperactivation and capacitation, since seminal plasma contains decapacitation factor(s). Seminal plasma was obtained by centrifugation of aliquots of liquefied semen layered over 1.5 ml 40.5% Percoll and mixed with human tubal fluid (HTF) medium containing 30 mg/ml human serum albumin (HSA) (HTF) to a final concentration of 5% (v/v) seminal plasma (SP). Motile spermatozoa were isolated from the remainder of the semen by swim-up into either HTF or SP medium. Samples were taken from each treatment immediately post-harvest (0 h) and after 60 min at 37 degrees C (1 h) for hyperactivation and capacitation assessment. The treatments were then divided into two portions, centrifuged and resuspended in either HTF or SP, giving HTF control and SP control treatments and two crossover treatments, 1 h HTF then 1 h SP (H/SP) and 1 h SP then 1 h HTF (SP/H). All tubes were incubated for a further 60 min at 37 degrees C before aliquots were taken for hyperactivation and capacitation assessments. Hyperactivation was estimated using an IVOS v10.6t (Hamilton Thorne Research, Beverly, MA, USA) 60 Hz CASA instrument, and capacitation was estimated using the chlortetracycline (CTC) method. The presence of seminal plasma in the capacitation medium for 60-120 min post-swim-up inhibited the development of hyperactivated motility. This inhibition was reversible, and was not prevented by preincubation for 1 h in HTF medium. There was no difference in the CTC binding patterns between treatments at 2 h, indicating that the capacitation-associated membrane changes were not affected by the presence of a low concentration of seminal plasma. There was no correlation between percentage capacitated and percentage hyperactivated spermatozoa for any treatment. Since the proportions of hyperactivated spermatozoa and capacitated spermatozoa were not related, we conclude that the processes leading to hyperactivation and to the membrane changes associated with capacitation are not tightly interlinked and consider this finding to be due to hyperactivated motility being associated with flagellar movement, while the CTC assay assesses changes in the Ca2+ levels of the sperm head plasma membrane.Keywords:
Capacitation
Hyperactivation
Percoll
A complex process of maturation called capacitation is an essential step for spermatozoa to fertilize oocytes. Recent studies have shown that reactive oxygen species (ROS) can enhance the capacitation of human spermatozoa and sperm-zona interaction. We have investigated whether hydrogen peroxide (H2O2) could trigger capacitation of human spermatozoa and the acrosome reaction. The addition of catalase, a specific H2O2 scavenger, at the beginning of the capacitation process decreased the levels of both hyperactivation and induced-acrosome reaction whereas catalase added 15 min before the induction of the acrosome reaction by the calcium ionophore had no effect. Supplementation of the medium with H2O2 resulted in increased levels of hyperactivation and the acrosome reaction, whereas H2O2 added 15 min before induction of the acrosome reaction did not have any stimulatory effect. These results suggest that H2O2 may be involved in the capacitation process of human spermatozoa but not in the acrosome reaction.
Capacitation
Acrosome reaction
Hyperactivation
Cite
Citations (212)
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.
Capacitation
Hyperactivation
Acrosome reaction
Cite
Citations (1)
The aim of this study was to evaluate the effects of Ca2+, BSA, NaHCO3 and PVA on the capacitation-associated time-dependent increase in protein tyrosine phosphorylation, hyperactivation, and acrosome reaction in hamster spermatozoa. Hamster spermatozoa when incubated in TALP, a medium that assists capacitation, showed a time-dependent increase in protein tyrosine phosphorylation that correlated with the capacitated state of the spermatozoa. An absence of Ca2+ or NaHCO3 in the capacitation medium delayed the phosphorylation of the proteins, but without both there was a significant decrease in the phosphorylation of the proteins throughout the period of capacitation. An absence of bovine serum albumin also caused a decrease in the phosphorylation of the proteins but this did not occur if polyvinyl alcohol was substituted for it in the medium. The percentage hyperactivation was not affected in the absence of bovine serum albumin if the medium contained polyvinyl alcohol. However, it was delayed in the absence of NaHCO3 and inhibited in the absence of Ca2+. The absence of NaHCO3 or bovine serum albumin had no effect on the acrosome reaction. These results show that hamster spermatozoa undergo capacitation-associated protein tyrosine phosphrylation similar to that of the spermatozoa of other mammals. However, hamster spermatozoa are unique in that the capacitation-associated protein tyrosine phosphorylation is not absolutely dependent on the presence of Ca2+ and NaHCO3. As far as we know, this study is the first to provide evidence that capacitation-associated protein tyrosine phosphorylation is linked to hyperactivation in hamster spermatozoa.
Capacitation
Hyperactivation
Acrosome reaction
Bovine serum albumin
Golden hamster
Cite
Citations (64)
The ability of strontium (Sr2+) to replace calcium (Ca2+) in maintaining human sperm function has still not been completely characterized. In the present study, acrosome reaction (AR) inducibility in response to human follicular fluid (hFF) was compared in spermatozoa incubated in either Ca2+- or Sr2+-containing media. Other events related to sperm capacitation, such as protein tyrosine phosphorylation and hyperactivation as well as zona pellucida (ZP) recognition under both conditions, were also analyzed. Spermatozoa incubated overnight in the presence of Sr2+ were unable to undergo the AR when exposed to hFF. Nevertheless, when spermatozoa were incubated under this condition and then transferred to medium with Ca2+, sperm response to hFF was similar to that of cells incubated throughout in the presence of Ca2+. The sperm protein tyrosine phosphorylation patterns and the percentages of sperm motility and hyperactivation were similar after incubation in Ca2+- or Sr2+-containing media. Under both conditions, the same binding capacity to homologous ZP was observed. Similar results were obtained when EGTA was added in order to chelate traces of Ca2+ present in Sr2+ medium. From these results, it can be concluded that Sr2+ can replace Ca2+ in supporting capacitation-related events and ZP binding, but not hFF-induced AR of human spermatozoa.
Capacitation
Hyperactivation
Acrosome reaction
EGTA
Follicular fluid
Cite
Citations (22)
In an attempt to understand the role of nitric oxide(NO) in sperm capacitation, in the present study, hamster spermatozoa were used to evaluate the effects of NO on motility, viability, hyperactivation, capacitation and protein tyrosine and serine phosphorylation using specific inhibitors of nitric oxide synthase (NOS); namely L-NAME (N-nito-L-aginine methyl ester) and 7-Ni (7-nitroindazole). The results indicated that L-NAME inhibits sperm motility, hyperactivation and acrosome reaction where as 7-Ni inhibits only hyperactivation and acrosome reaction thus implying that NOS inhibitors exhibit subtle differences with respect to their effects on sperm functions. This study also provides evidence that NOS inhibitors inhibit sperm capacitation by their ability to modulate protein tyrosine phosphorylation. However, the inhibitors had no effect on the protein serine phosphorylation of hamster spermatozoa during capacitation. Thus, these results indicate that NO is required
Capacitation
Hyperactivation
Acrosome reaction
Cite
Citations (19)
Mouse sperm were incubated in medium with or without 24 mM lactate and assessed for 1) motility characteristics including hyperactivation--a computer-assisted motion analysis system was used; 2) capacitation--a chlortetracycline fluorescent dye binding assay was used; and 3) ability to penetrate oocytes. Lactate affected all aspects of motility and delayed the rates of both hyperactivation and capacitation. When a concentration of 8 x 10(3) sperm/ml was used for insemination in vitro, sperm preincubated 60-90 minutes in medium with lactate prior to insemination in lactate-free medium fertilized fewer oocytes than did sperm preincubated in lactate-free medium. Use of a calcium-sensitive electrode demonstrated that lactate chelated appreciable amounts of calcium in the medium. Capacitation was assayed in sperm incubated 60 minutes in medium with various concentrations of lactate or CaCl2. When medium containing lactate was compared to medium without lactate but having a similar level of free calcium, the level of capacitation of sperm incubated with lactate was less than half that of sperm incubated without lactate. These results demonstrate that including 24 mM lactate in the medium can have detrimental effects on mouse sperm hyperactivation and capacitation. The detrimental effects on capacitation are partly but not completely due to the chelation of calcium by lactate.
Capacitation
Hyperactivation
Cite
Citations (23)
Hyperactivation
Capacitation
Cite
Citations (53)
Mammalian sperm differ widely in sperm morphology, and several explanations have been presented to account for this diversity. Less is known about variation in sperm physiology and cellular processes that can give sperm cells an advantage when competing to fertilize oocytes. Capacitation of spermatozoa, a process essential for mammalian fertilization, correlates with changes in motility that result in a characteristic swimming pattern known as hyperactivation. Previous studies revealed that sperm motility and velocity depend on the amount of ATP available and, therefore, changes in sperm movement occurring during capacitation and hyperactivation may involve changes in sperm bioenergetics. Here, we examine differences in ATP levels of sperm from three mouse species (genus
Hyperactivation
Capacitation
Bioenergetics
Cite
Citations (27)
After leaving the testis, mammalian spermatozoa from many species are morphologically differentiated but have acquired neither progressive motility nor the ability to fertilize a metaphase II-arrested egg. During epididymal transit, sperm acquire the ability to move progressively; however, they are still fertilization incompetent. Fertilization capacity is gained after residence in the female tract for a finite period of time. The physiological changes that confer on the sperm the ability to fertilize are collectively called ‘‘capacitation.’’ Capacitation was first described and defined independently by Chang [1, 2] and Austin [3, 4]. The definition of this poorly understood phenomenon has been modified and narrowed over the years. Although fertilization still represents the benchmark endpoint of a capacitated sperm, the ability of the sperm to undergo a regulated acrosome reaction (e.g., in response to the zona pellucida) can be taken as an earlier, upstream endpoint of this extratesticular maturational event. It must be stressed at this point that capacitation is also correlated with changes in sperm motility patterns, designated as sperm hyperactivation, in a number of species [5, 6]. There are examples of cases in which capacitation and hyperactivation can be dissociated experimentally [7], but one cannot yet argue that hyperactivation of motility represents an event completely independent of the capacitation process [6]. Therefore, when one attempts to understand the process of capacitation at the molecular level, it is necessary to consider events occurring both in the head (i.e., acrosome reaction) and in the tail (i.e., motility changes). The physiological site of capacitation in vivo is the oviduct or the uterus, depending on the species [5]. However, capacitation in vitro has been accomplished using cauda and/or ejaculated sperm incubated under a variety of conditions in defined media that mimic the electrolyte composition of the oviduct fluid. In most cases, these media contain energy substrates such as pyruvate, lactate, and glucose (depending on the species); a protein source that usually is serum albumin; NaHCO3; and Ca21. The action of these media components to promote capacitation at the molecular level is poorly understood and will be discussed in this review. This review is not intended to provide an ex-
Capacitation
Hyperactivation
Acrosome reaction
Pronucleus
Cite
Citations (489)
While hyperactivated motility is known to be a concomitant of capacitation, and a prerequisite for fertilization, the specific interdependence of capacitation and hyperactivation in human spermatozoa has not been investigated. This study was designed to determine the effect of seminal plasma contamination on the expression of hyperactivated motility and the relationship between hyperactivation and capacitation, since seminal plasma contains decapacitation factor(s). Seminal plasma was obtained by centrifugation of aliquots of liquefied semen layered over 1.5 ml 40.5% Percoll and mixed with human tubal fluid (HTF) medium containing 30 mg/ml human serum albumin (HSA) (HTF) to a final concentration of 5% (v/v) seminal plasma (SP). Motile spermatozoa were isolated from the remainder of the semen by swim-up into either HTF or SP medium. Samples were taken from each treatment immediately post-harvest (0 h) and after 60 min at 37 degrees C (1 h) for hyperactivation and capacitation assessment. The treatments were then divided into two portions, centrifuged and resuspended in either HTF or SP, giving HTF control and SP control treatments and two crossover treatments, 1 h HTF then 1 h SP (H/SP) and 1 h SP then 1 h HTF (SP/H). All tubes were incubated for a further 60 min at 37 degrees C before aliquots were taken for hyperactivation and capacitation assessments. Hyperactivation was estimated using an IVOS v10.6t (Hamilton Thorne Research, Beverly, MA, USA) 60 Hz CASA instrument, and capacitation was estimated using the chlortetracycline (CTC) method. The presence of seminal plasma in the capacitation medium for 60-120 min post-swim-up inhibited the development of hyperactivated motility. This inhibition was reversible, and was not prevented by preincubation for 1 h in HTF medium. There was no difference in the CTC binding patterns between treatments at 2 h, indicating that the capacitation-associated membrane changes were not affected by the presence of a low concentration of seminal plasma. There was no correlation between percentage capacitated and percentage hyperactivated spermatozoa for any treatment. Since the proportions of hyperactivated spermatozoa and capacitated spermatozoa were not related, we conclude that the processes leading to hyperactivation and to the membrane changes associated with capacitation are not tightly interlinked and consider this finding to be due to hyperactivated motility being associated with flagellar movement, while the CTC assay assesses changes in the Ca2+ levels of the sperm head plasma membrane.
Capacitation
Hyperactivation
Percoll
Cite
Citations (134)