Elevating intracellular calcium levels in human sperm using an internal calcium ATPase inhibitor, 2,5-di(tert-butyl) hydroquinone (TBQ), initiates capacitation and the acrosome reaction but only in the presence of extracellular calcium

Prostaglandins (PGs) have been reported to be present in the seminal fluid and cervical mucus, affecting different stages of sperm maturation from spermatogenesis to the acrosome reaction. This study assessed the effects of low physiological PGE2 and PGF2α concentrations on human sperm motility and on the ability of the spermatozoa to bind to the zona pellucida (ZP). Human spermatozoa were isolated from seminal samples with normal concentration and motility parameters and incubated with 1 μM PGE2, 1 μM PGF2α or control solution to determine sperm motility and the ability to bind to human ZP. The effects of both PGs on intracellular calcium levels were determined. Incubation for 2 or 18 h with PGE2 or PGF2α resulted in a significant (P < 0.05) increase in the percentage of spermatozoa with progressive motility. In contrast with PGF2α, PGE2 alone induced an increase in sperm intracellular calcium levels; however, the percentage of sperm bound to the human ZP was doubled for both PGs. These results indicate that incubation of human spermatozoa with low physiological levels of PGE2 or PGF2α increases sperm functions and could improve conditions for assisted reproduction protocols.

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β-Elemene Inhibits Human Sperm Function by Affecting Sperm Vitality and Intracellular Calcium

Cellular Physiology and Biochemistry ◽

10.1159/000495821 ◽

2018 ◽

Vol 51 (5) ◽

pp. 2019-2029 ◽

Cited By ~ 1

Author(s):

Wen Chen ◽

Shi-qi Weng ◽

Meng-ge Lv ◽

Wen-qiong Chen ◽

Zhuo-fei Bi ◽

...

Keyword(s):

Intracellular Calcium ◽

Acrosome Reaction ◽

A549 Cells ◽

Human Sperm ◽

Underlying Mechanism ◽

Computer Assisted ◽

Sperm Function ◽

Dependent Manner ◽

Sperm Analysis

Background/Aims: β-Elemene is a bioactive sesquiterpene compound that exhibits a potent anti-tumor effect and is used in various clinical applications. However, little is known about its effect on the male reproductive system. The objective of this study was to investigate the in vitro actions of β-elemene on human sperm function and elucidate the underlying mechanism. Methods: The cytotoxicity of β-elemene toward MCF-10A, MDA-MD-231, and A549 cells was evaluated with cell proliferation and colony formation assays. Additionally, human sperm were treated with different concentrations (0, 10, 20, 40, 80, 160, and 320 µM) of β-elemene in vitro. The characteristics in human sperm essential for fertilization, including vitality, motility, capacitation, acrosome reaction, responsiveness to progesterone, and intracellular calcium concentration ([Ca2+]i) were examined with a computer-assisted sperm analysis system, chlortetracycline staining, and a fluorescent Ca2+ indicator. Results: A comprehensive evaluation of sperm motility, especially hyperactivated motility, revealed that treatments with 40–320 μM β-elemene decreased human sperm vitality, motility (total motility, progressive motility, and curvilinear velocity), and penetrating ability in a dose-dependent manner, but were non-toxic or minimally toxic toward MCF-10A, MDA-MD-231, and A549 cells. Although 10 and 20 μM β-elemene did not affect sperm vitality and motility, these concentrations increased the spontaneous acrosome reaction and inhibited progesterone-induced sperm functions by affecting sperm [Ca2+]i. Conclusion: These results suggest that β-elemene inhibits human sperm function by affecting sperm vitality and [Ca2+]i. These observations must be considered when using β-elemene to treat cancer patients who may wish to preserve their fertility.

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Effect of fibronectin on proteasome activity, acrosome reaction, tyrosine phosphorylation and intracellular calcium concentrations of human sperm

Human Reproduction ◽

10.1093/humrep/dem023 ◽

2007 ◽

Vol 22 (5) ◽

pp. 1420-1430 ◽

Cited By ~ 32

Author(s):

Emilce S. Diaz ◽

Milene Kong ◽

Patricio Morales

Keyword(s):

Intracellular Calcium ◽

Tyrosine Phosphorylation ◽

Acrosome Reaction ◽

Human Sperm ◽

Proteasome Activity

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Hyaluronic acid enhances induction of the acrosome reaction of human sperm through interaction with the PH-20 protein

Zygote ◽

10.1017/s0967199498000021 ◽

1998 ◽

Vol 6 (2) ◽

pp. 103-111 ◽

Cited By ~ 47

Author(s):

Khalida Sabeur ◽

Gary N. Cherr ◽

Ashley I. Yudin ◽

James W. Overstreet

Keyword(s):

Hyaluronic Acid ◽

Intracellular Calcium ◽

Direct Effect ◽

Zona Pellucida ◽

Acrosome Reaction ◽

Human Sperm ◽

Enhancing Effect ◽

Fab Fragments ◽

Progesterone Treatment ◽

Data Support

When capacitated human sperm were treated with hyaluronic acid (HA) for 30 min prior to the addition of progesterone or solubilised human zonae pellucidae, there was a significant increase in the percentage of acrosome reactions. Progesterone treatment alone increased acrosome reactions from 10.5% to 21.8% and pretreatment with 100 µg/ml HA resulted in 33.0% acrosome reactions. With zonae pellucidae treatment alone the increase was from 9.0% to 23.5% and with HA pretreatment it was 48.8%. HA treatment alone had no direct effect on acrosome reactions, and the enhancing effect of HA was not removed when sperm were washed prior to the addition of either acrosome reaction agonist. Experiments with sperm 5 min after HA treatment demonstrated that enhancement of acrosome reactions was apparent as early as 1 min after addition of zonae and within 5 min after addition of progesterone. When sperm were pretreated with Fab fragments of anti-PH-20 IgG, then with HA and then with progesterone or zonae pellucidae, there was no enhancement of the acrosome reaction. Fab treatment did not induce acrosome reactions and did not interfere with the action of either agonist in the absence of HA. Sperm that were treated with HA had significantly higher intracellular calcium levels, and pretreatment with Fab reduced this increase to 42.7%. Addition of progesterone to HA-treated sperm was followed by another large increase in intracellular calcium, which was lower when sperm were pretreated with Fab. These results suggest that HA interacts with the PH-20 protein to increase basal levels of intracellular calcium and thereby potentiates the acrosome reaction. The data support the hypothesis that HA in the cumulus matrix may act to prime the fertilising sperm for induction of the acrosome reaction by constituents of the cumulus and/or zona pellucida.

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