Intracellular calcium increase and acrosome reaction in response to progesterone in human spermatozoa are correlated with in-vitro fertilization

Krausz, Csilla; Bonaccorsi, Lorella; Luconi, Michaela; Fuzzi, Beatrice; Criscuoli, Luciana; Pellegrini, Sandra; Forti, Gianni; Baldi, Elisabetta

doi:10.1093/humrep/10.1.120

Cited by 96 publications

(82 citation statements)

References 9 publications

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“…Isolation, sequencing, and further functional characterization of these two protein candidates of nongenomic P receptors are presently under investigation in our laboratory. As we have recently shown that a correlation exists between sperm responsiveness to P and sperm fertilizing ability (29,46), identification and characterization of nongenomic P receptor(s) may be clinically relevant not only in future research in male infertility, but also in the development of new contraceptive tools.…”

Section: Tablementioning

confidence: 99%

Identification and Characterization of Functional Nongenomic Progesterone Receptors on Human Sperm Membrane1

Luconi

Bonaccorsi

Maggi

et al. 1998

The Journal of Clinical Endocrinology &Amp; Metabolism

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The presence of functional nongenomic progesterone (P) receptors in human spermatozoa has been investigated by equilibrium binding studies in intact spermatozoa, ligand blot and Western blot analysis of sperm lysates, as well as determination of the effects of the steroid on sperm intracellular Ca 2ϩ concentrations. Binding experiments were performed using progesterone-11␣-glucuronide-[125 I]iodotyramine as tracer. Computer analysis of competition curves using different steroids as competitors indicated the presence of two distinct binding sites for P. The high affinity site (K d in the nanomolar range) appears to be specific for P, whereas the low affinity one (K d in the micromolar range) binds with equal affinity 11␤-hydroxyprogesterone (11␤OHP) and 17␣-hydroxyprogesterone (17␣OHP). A significant correlation exists among affinity constants (as determined by binding studies) and EC 50 values for the effects of P, 11␤OHP, and 17␣OHP on intracellular Ca 2ϩ in fura-2-loaded spermatozoa, strongly indicating the involvement of P-binding sites in the biological effect of the steroid. In particular, dose-response curves for P were biphasic, with an EC 50 in the nanomolar range and another in the micromolar range. Conversely, curves for 11␤OHP and 17␣OHP were monophasic, with an EC 50 just in the micromolar range. Ligand blot analysis of sperm total lysates performed with peroxidase-conjugated P revealed the presence of two binding proteins of 54 and 57 kDa that were specific for P. Indeed, peroxidase-conjugated P binding was blocked by the simultaneous presence of the unconjugated steroid. Using ␣c262 antibody, which is directed against the P-binding domain of genomic receptor, we detected two proteins of similar molecular mass (54 and 57 kDa), whereas using antibodies directed against the DNA-binding and N-terminal domains of the genomic P receptors, the two proteins were not detected. In addition, p54 and p57 appear to be mostly localized in sperm membranes and virtually absent in the cytoplasm. The involvement of these proteins in the biological effects of P is indicated by the strong inhibitory effect of ␣c262 on P-induced acrosome reaction of capacitated human spermatozoa. (J Clin Endocrinol Metab 83: [877][878][879][880][881][882][883][884][885] 1998) A CROSOME reaction (AR) is an essential event of the process of fertilization. In mammals, physiological AR occurs after interaction with the zona pellucida, the glycoprotein coat overlying the egg plasma membrane (1), and is mediated by specific sperm receptor (2). During the process of fertilization, AR can also be induced by progesterone (P), which is present in high concentrations in the cumulus matrix that surrounds the oocyte and in the follicular fluid (3, 4). In particular, in human spermatozoa, P induces a rapid influx of calcium, calcium-dependent phosphoinositide hydrolysis, an increase in tyrosine phosphorylation of sperm proteins, and chloride efflux, ultimately leading to stimulation of AR (for review, see Ref. 5). In addition, in vitro st...

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Section: Tablementioning

confidence: 99%

Identification and Characterization of Functional Nongenomic Progesterone Receptors on Human Sperm Membrane1

Luconi

Bonaccorsi

Maggi

et al. 1998

The Journal of Clinical Endocrinology &Amp; Metabolism

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“…Spermatozoa were washed from seminal plasma and prepared by the swim-up procedure as described previously [16]. In some experiments, spermatozoa were separated on a Percoll gradient as described [5,17].…”

Section: Preparation Of Spermatozoamentioning

confidence: 99%

Tyrosine kinase inhibition reduces the plateau phase of the calcium increase in response to progesterone in human sperm

et al. 1995

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Progesterone (P) has previously been shown to induce a rapid increase in [Ca2+]i as well as tyrosine pbosphorylation of proteins in human spermatozoa. Both these effects are essential for induction of the acrosome reaction by P. We investigated a possible relationship between the P-induced calcium increase and tyrosine kinase activation, by evaluating the effect of the tyrosine kinase inhibitor genistein on these two effects. We found that preincubation with genistein abolished P-induced tyrosine phosphorylation of two sperm proteins of 97 and 75 kDa molecular weight and significantly inhibited the plateau phase of P-induced [CaZ÷]i increase without affecting the peak phase. Conversely, the plateau phase was enhanced by the tyrosine phosphatase inhibitor Na3VO 4. The effect of genistein was specific for P, since no inhibition was observed on the [Ca2+]i increase induced by thapsigargin, an inhibitor of endoplasmic Ca2+-ATPase previously shown to mobilize Ca 2+ in spermatozoa. These results indicate that tyrosine kinase activation is involved in the generation of the plateau phase of Ca 2+ influx induced by P, and suggest the possibility that two different pathways are involved in the induction of Ca 2+ entry by P in human sperm.

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“…In humans, male factor infertility is highly correlated with failure of AR and/or the events that activate AR (1)(2)(3)(4). It is believed that the primary activator of AR in mammals is binding of the spermatozoon to the ZP (5), although AR can also be induced by progesterone (6 -8).…”

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confidence: 99%

Identification and Localization of T-type Voltage-operated Calcium Channel Subunits in Human Male Germ Cells

Jagannathan

Punt

et al. 2002

Journal of Biological Chemistry

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Low voltage activated, voltage-operated Ca2؉ channels are expressed in rodent male germ cells and are believed to be pivotal in induction of the acrosome reaction in mouse spermatozoa. However, in humans, very little is known about expression of voltage-operated Ca 2؉ channels in male germ cells or their function. We have used reverse transcription-polymerase chain reaction, in situ hybridization, and patch clamp recording to investigate the expression of low voltage activated voltage-operated Ca 2؉ channels in human male germ cells. We report that full-length transcripts for both ␣ 1G and ␣ 1H low voltage activated channel subunits are expressed in human testis. Multiple isoforms of ␣ 1G are present in the testis and at least two isoforms of ␣ 1H , including a splice variant not previously described in the human. Transcripts for all the isoforms of both ␣ 1G and ␣ 1H were detected by reverse transcription-polymerase chain reaction on mRNA isolated from human spermatogenic cells. In situ hybridization for ␣ 1G and ␣ 1H localized transcripts both in germ cells and in other cell types in the testis. Within the seminiferous tubules, ␣ 1H was detected primarily in germ cells. Using the whole cell patch clamp technique, we detected T-type voltageoperated Ca 2؉ channel currents in isolated human male germ cells, although the current amplitude and frequency of occurrence were low in comparison to the occurrence of T-currents in murine male germ cells. We conclude that low voltage activated voltage-operated Ca 2؉ channels are expressed in cells of the human male germ line.

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Intracellular calcium increase and acrosome reaction in response to progesterone in human spermatozoa are correlated with in-vitro fertilization

Cited by 96 publications

References 9 publications

Identification and Characterization of Functional Nongenomic Progesterone Receptors on Human Sperm Membrane1

Identification and Characterization of Functional Nongenomic Progesterone Receptors on Human Sperm Membrane1

Tyrosine kinase inhibition reduces the plateau phase of the calcium increase in response to progesterone in human sperm

Identification and Localization of T-type Voltage-operated Calcium Channel Subunits in Human Male Germ Cells

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