scholarly journals Matrine Inhibits Mouse Sperm Function by Reducing Sperm [Ca2+]i and Phospho-ERK1/2

2015 ◽  
Vol 35 (1) ◽  
pp. 374-385 ◽  
Author(s):  
Tao Luo ◽  
Qian-xing Zou ◽  
Yuan-qiao He ◽  
Hua-feng Wang ◽  
Na Li ◽  
...  
Keyword(s):  
Acrosome Reaction ◽  
Male Reproduction ◽  
In Vitro Toxicity ◽  
Sperm Function ◽  
Ionophore A23187 ◽  
Epididymal Sperm ◽  
Mouse Sperm ◽  
Extracellular Signal ◽  
Mature Mouse

Background: Matrine is a bioactive alkaloid that has a variety of pharmacological effects and is widely used in Chinese medicine. However, its effects on male reproduction are not well known. In this study, we aimed to investigate the in vitro toxicity of matrine on mature mouse sperm. Methods: Mouse cauda epididymal sperm were exposed to matrine (10-200 µM) in vitro. The viability, motility, capacitation, acrosome reaction and fertilization ability of the mouse sperm were examined. Furthermore, the intracellular calcium concentration ([Ca2+]i), calcium (Catsper) and potassium (Ksper) currents, and phosphorylation of extracellular signal regulated kinases 1/2 (p-ERK1/2) of the sperm were analyzed. Results: After exposure to 100 µM or more of matrine, mouse cauda epididymal sperm exhibited a significant reduction in total motility, progressive motility, linear velocity and acrosome reaction rate induced by Ca2+ ionophore A23187. As a result, the fertilization ability of mouse sperm was remarkably decreased by matrine. Our data further demonstrated that matrine significantly reduced sperm [Ca2+]i and [Ca2+]i-related p-ERK1/2; however, both the CatSper and KSper currents, which are thought to interactively regulate Ca2+ influx in sperm, were not affected by matrine. Conclusion: Our findings indicate that matrine inhibits mouse sperm function by reducing sperm [Ca2+]i and suppressing the phosphorylation of ERK1/2.

scholarly journals Mouse gamete interactions during fertilization in vitro. Chlortetracycline as a fluorescent probe for the mouse sperm acrosome reaction.

1979 ◽  
Vol 83 (3) ◽  
pp. 544-555 ◽  
Author(s):  
P M Saling ◽  
B T Storey
Keyword(s):  
Plasma Membrane ◽  
Fluorescent Probe ◽  
Zona Pellucida ◽  
Acrosome Reaction ◽  
Sperm Head ◽  
Fertilization In Vitro ◽  
Ionophore A23187 ◽  
Mouse Sperm ◽  
Sperm Acrosome

We have developed an assay for detecting the acrosome reaction in mouse sperm using chlortetracycline (CTC) as a fluorescent probe. Sperm known to be intact with nonreacted acrosomes show CTC fluorescence in the presence of Ca2+ over the anterior portion of the sperm head on the plasma membrane covering the acrosome. Sperm which have undergone the acrosome reaction do not show fluorescence on the sperm head. Mouse sperm bind to zonae pellucidae of cumulus-free eggs in vitro in a Ca2+-dependent reaction; these sperm are intact by the CTC assay. Intact sperm bind to mechanically isolated zonae under the same conditions: the egg is apparently unnecessary for this inital reaction. Sperm suspensions, in which greater than 50% of the motile population had completed the acrosome reaction, were prepared by incubation in hyperosmolal medium followed by treatment with the divalent cation ionophore, A23187. Cumulus-free eggs challenged with such sperm suspensions preferentially bind intact sperm; acrosome-reacted sperm do not bind. We conclude that the plasma membrane of the mouse sperm is responsible for recognition of the egg's zona pellucida and that the obligatory sequence of reactions leading to fusion of mouse gametes is binding of the intact sperm to the zona pellucida, followed by the acrosome reaction at the zona surface, followed in turn by sperm penetration of the zona.

scholarly journals Evidence that aggregation of mouse sperm receptors by ZP3 triggers the acrosome reaction.

1989 ◽  
Vol 108 (6) ◽  
pp. 2163-2168 ◽  
Author(s):  
L Leyton ◽  
P Saling
Keyword(s):  
Acrosome Reaction ◽  
Specific Binding ◽  
Polyclonal Antibodies ◽  
Subsequent Treatment ◽  
Mouse Sperm ◽  
Fab Fragments ◽  
Sperm Binding ◽  
Extracellular Signal ◽  
Acrosomal Exocytosis ◽  
Rabbit Igg

In the mouse, considerable evidence indicates that initial sperm binding to the zona pellucida (ZP) is mediated by ZP3. In addition, this same glycoprotein is also responsible for inducing the acrosome reaction (AR). Whereas the O-linked oligosaccharides of ZP3 appear to mediate sperm-ZP binding, the portion of ZP3 bearing AR activity has not been defined. To try to understand the bifunctional role of ZP3 (binding and AR inducing activities), we have examined the hypothesis that ZP3 aggregates sperm receptor molecules. By analogy with findings in a variety of other extracellular signal transducing systems, including receptors for growth factors and insulin, this aggregation event could initiate the cascade resulting in the AR. To test this hypothesis, we have generated monospecific polyclonal antibodies against ZP2 and against ZP3, and examined the effects of these probes on capacitated sperm incubated in the absence or presence of various ZP protein preparations. For some experiments, we have used proteolytic fragments of ZP3, a preparation known to retain specific binding, but not AR-inducing, activity. We show here that capacitated mouse sperm, incubated with ZP glycopeptides, displayed ARs when incubated subsequently with anti-ZP3 IgG; ARs did not occur when parallel sperm samples were incubated with anti-ZP2 IgG or with anti-ZP3 Fab fragments. When capacitated sperm were treated successively, with (a) ZP3 glycopeptides, (b) anti-ZP3 Fab fragments, and (c) goat anti-rabbit IgG, ARs occurred in the majority of sperm. An alternative approach to examine this hypothesis used ZP proteins obtained from tubal eggs treated previously with bioactive phorbol diester (12-O-tetradecanoyl phorbol-13-acetate [TPA]). This preparation arrests capacitated sperm in an intermediate state of the AR. We demonstrate here that these sperm can be induced to undergo a complete AR by subsequent treatment with anti-ZP3 IgG. Together, these findings are consistent with the hypothesis under examination, and suggest that the aggregation of sperm molecules recognized by ZP3 glycopeptides or by TPA-treated ZP is sufficient to trigger the events that occur during acrosomal exocytosis.

scholarly journals Polyphosphoinositide breakdown and subsequent exocytosis in the Ca2+/ionophore-induced acrosome reaction of mammalian spermatozoa

1989 ◽  
Vol 259 (2) ◽  
pp. 397-406 ◽  
Author(s):  
E R S Roldan ◽  
R A P Harrison
Keyword(s):  
Acrosome Reaction ◽  
Fertilization In Vitro ◽  
Ionophore A23187 ◽  
Bivalent Cation ◽  
Phosphoinositide Breakdown ◽  
Phosphoinositide Cycle ◽  
Phosphatidylinositol 4 ◽  
Sperm Acrosome Reaction ◽  
Sperm Acrosome

An investigation was made of the modifications in phospholipids that occur during the exocytotic event known as the ‘sperm acrosome reaction’. Phospholipids were prelabelled with 32P, and exocytosis was induced with Ca2+ and the ionophore A23187. When incubated with [32P]Pi in various media suitable for supporting sperm survival or fertilization in vitro, spermatozoa from all five species examined (ram, boar, guinea pig, mouse and human) incorporated 32P rapidly into the components of the phosphoinositide cycle. There were differences both between species and between media with respect to the actual rate of incorporation of label, and also between species with respect to other phospholipids labelled. Treatment of spermatozoa with Ca2+ and A23187 to induce the acrosome reaction resulted in a rapid breakdown of phosphatidylinositol 4, 5-bisphosphate and phosphatidylinositol 4-phosphate, which was complete within 3 min; there was also a great increase in labelling of phosphatidate. Occurrence of acrosome reactions in the sperm population was only observed after 5-10 min and reached a maximum response of greater than 90% after more than 30 min. The phosphoinositide breakdown was related to subsequent exocytosis: after EGTA/ionophore treatment, neither inositide breakdown nor exocytosis took place; however, later addition of Ca2+ resulted in immediate inositide breakdown, and exocytosis followed, with a delay relative to Ca2+ addition exactly similar to that following standard Ca2+/ionophore treatment. Neomycin inhibited both inositide breakdown and subsequent exocytosis provided it was added together with Ca2+ and ionophore; however, if the drug was added 3 min after Ca2+ and ionophore (by which time inositide breakdown was already complete), exocytosis was not inhibited. Ca2+ seemed to have several consecutive roles in the acrosome reaction. Low (micromolar) levels of free Ca2+ were needed both for phosphoinositide breakdown and for an event downstream of this breakdown; no other bivalent cation could substitute for Ca2+ in either event, and inositide breakdown was actually inhibited by Mg2+. In addition, millimolar levels of Ca2+ were needed for later stages of exocytosis, although this requirement could be satisfied by Sr2+. We conclude that breakdown of polyphosphoinositides is an essential early process after Ca2+ entry in the chain of events that lead to exocytosis in the mammalian sperm acrosome reaction.

In vitro fertilisation of Chinese hamster oocytes by spermatozoa that have undergone ionophore A23187-induced acrosome reaction, and their subsequent development into blastocysts

Zygote ◽  
1996 ◽  
Vol 4 (2) ◽  
pp. 93-99 ◽  
Author(s):  
Hiroyuki Tateno ◽  
Yujiroh Kamiguchi
Keyword(s):  
Gas Phase ◽  
Acrosome Reaction ◽  
Chinese Hamster ◽  
Subsequent Development ◽  
In Vitro Fertilisation ◽  
Ionophore A23187 ◽  
Cell Stage ◽  
Developmental Arrest ◽  
Potential Use

SummaryTo enhance potential use of the Chinese hamster, Cricetulus griseus, in developmental and cytogenetic studies of mammalian gametes and embryos, techniques for in vitro fertilisation and embryo culture were developed in the species. Spermatozoa were recovered from the vasa deferentia of mature males, and incubated in modified TYH medium for 1 h at 37°C under 5% CO2 in air. They were then treated with ionophore A23187 (20¼M) for 10min to induce the acrosome reaction. Following ionophore treatment, superovulated oocytes were collected from hormonally stimulated females and incubated with the acrosome-reacted spermatozoa for 2 h at 37°C under 5% CO2 in air. In this study, 245 oocytes ova (98.0%) were determined to be monospermic. The monospermic ova were then cultured in TYH supplemented with 1mM hypotaurine under the same gas phase. Within 30h of fertilisation, 182 ova (93.8%) cleaved to the 2-cell stage, and subsequently 163 ova (84.0%) developed beyond the 2-cell stage. Thus, obstinate developmental arrest at the 2-cell stage(‘2-cell block’) was not observed in this species. Ultimately, 65.5% of monospermic ova reached morula to blastocyst stages.

In vitro induction of the acrosome reaction in ovine spermatozoa by calcium ionophore A23187

2003 ◽  
Vol 51 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Ö. Uçar ◽  
T. J. Parkinson
Keyword(s):  
Phase Contrast ◽  
Acrosome Reaction ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Contrast Microscopy ◽  
The Relationship ◽  
In Vitro Induction ◽  
Artificial Vagina

The relationship between concentration of calcium ionophore A23187 and incubation time upon the proportion of spermatozoa undergoing acrosome reaction (AR) in vitro was investigated in rams from a commercial artificial insemination (AI) program. Two ejaculates were collected by artificial vagina from each of nine rams of three breeds (Finn Dorset, Charolais and Suffolk) aged 8-36months. Each ejaculate was diluted in a skimmed milk extender. Spermatozoa were thereafter incubated for 45 or 60min in modified Tyrode's medium (TALP) which contained either zero, 0.1 or 1.0µM/l A23187. After fixing in 10% formaldehyde, the number of spermatozoa that had undergone AR was determined by phase contrast microscopy. In pre-incubation samples, 21.3± 3.3% of spermatozoa had undergone AR. Percentages of acrosome reacted spermatozoa were significantly (P<0.001) increased after incubation with A23187. After incubation with 0.1µM/l A23187 for 45 and 60min there were 22.4±3.0% and 31.7±4.3% acrosome reacted spermatozoa, respectively. After incubation with 1.0µM/l A23187 for 45 and 60min there were 46.2±6.5% and 53.8±5.9% acrosome reacted spermatozoa, whilst corresponding numbers in control samples were 17.0±2.7% and 22.3±4.2%. There was also a significant (P<0.001) effect of individual animals upon the responses to different concentrations of A23187. These findings indicate that (i) A23187 can be used to assess the AR of ovine spermatozoa in vitro and (ii) there are effects of individual animals upon the proportion of spermatozoa undergoing AR.

scholarly journals Increased calcium-ion influx is a component of capacitation of spermatozoa

1978 ◽  
Vol 172 (3) ◽  
pp. 549-556 ◽  
Author(s):  
J P Singh ◽  
D F Babcock ◽  
H A Lardy
Keyword(s):  
Calcium Ion ◽  
Time Course ◽  
Acrosome Reaction ◽  
Local Anaesthetics ◽  
Defined Medium ◽  
Ionophore A23187 ◽  
Net Uptake ◽  
Ion Influx ◽  
Triton X

Capacitation (modifications required for gamete fusion) is produced by incubating guinea-pig spermatozoa in vitro in a chemically defined medium. It is shown that during such incubation a net uptake of Ca2+ by the sperm occurs in two distinguishable phases. An initial loose association of Ca2+, possibly to surface sites, is unaffected by agents (Mg2+, inhibitors of mitochondiral function) that prevent or delay the exocytotic spermatozoal acrosome reaction. The time course of a secondary Ca2+ uptake parallels or slightly precedes the time course of the acrosome reaction. This parallelism is maintained during a variety of treatments that either expedite (local anaesthetics, ionophore A23187, Triton X-100) or delay (Mg2+, low external Ca2+) the acrosome reaction. We conclude that the secondary Ca2+ influx described herein apparently serves to link alterations of the spermatozoal membrane to subsequent contractile and secretory components of the capacitation sequence.

Effects of the environmental endocrine disruptors di-2-ethylhexyl phthalate and mono-2-ethylhexyl phthalate on human sperm function in vitro

2020 ◽  
Vol 32 (6) ◽  
pp. 629
Author(s):  
Xinyi Sun ◽  
Wenqiong Chen ◽  
Shiqi Weng ◽  
Tingting Pan ◽  
Xiaonian Hu ◽  
...  
Keyword(s):  
Tyrosine Phosphorylation ◽  
Membrane Integrity ◽  
Human Sperm ◽  
Male Reproduction ◽  
Human Spermatozoa ◽  
Mitochondrial Activity ◽  
Sperm Function ◽  
Endocrine Disrupting Chemical ◽  
Ethylhexyl Phthalate

Di-2-ethylhexyl phthalate (DEHP), a plastic-derived, endocrine-disrupting chemical, has been shown to exhibit male reproductive toxicity. However, its effects on human mature spermatozoa are largely unknown. In this study we investigated the invitro effects of DEHP and mono-2-ethylhexyl phthalate (MEHP; the main metabolite of DEHP) on sperm function and the mechanisms involved. Human spermatozoa were exposed to phthalates invitro at the doses that cover the concentrations detected in human semen: 20nM–8 μM DEHP, 1nM–20 μM MEHP or a mixture of 20nM–8 μM DEHP and 1nM–20 μM MEHP. DEHP and MEHP, alone or in combination, had no effect on the viability, membrane integrity, motility, homeostasis of reactive oxygen species or mitochondrial activity of human spermatozoa. Interestingly, 1nM–20 μM MEHP and combinations of 20nM–8 μM DEHP and 1nM–20 μM MEHP enhanced penetration ability, hyperactivation and the spontaneous acrosome reaction of human spermatozoa, and increased intracellular free Ca2+ concentrations ([Ca2+]i) and tyrosine phosphorylation, two key signalling pathways that regulate sperm function. The findings of this study suggest that invitro exposure to MEHP metabolised from DEHP affects human sperm function by inducing increases in sperm [Ca2+]i and tyrosine phosphorylation, which adds to our understanding of the effects of DEHP on male reproduction.

scholarly journals Ejaculated Mouse Sperm Enter Cumulus-Oocyte Complexes More Efficiently In Vitro than Epididymal Sperm

PLoS ONE ◽  
2015 ◽  
Vol 10 (5) ◽  
pp. e0127753 ◽  
Author(s):  
Honggang Li ◽  
Pei-hsuan Hung ◽  
Susan S. Suarez
Keyword(s):  
Epididymal Sperm ◽  
Mouse Sperm
Sign in / Sign up

Export Citation Format

Share Document