Effect of Heparin-Reduced Glutathione on Hamster Sperm DNA Unpacking and Nuclear Swelling

Reyes, R.; Sánchez-Vázquez, M L; Merchant‐Larios, Horacio; Rosado, Adolfo; Delgado, N. M.

doi:10.3109/01485019608988500

Cited by 13 publications

(9 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Our previous results [Delgado et al 2001;Reyes et al 1996;Sánchez-Vázquez et al 1996] and those presented here strengthen the hypothesis that GSH induces disulphide bound reduction between protamines, while the heparin induces sperm nuclei swelling by mediating the release of histone H1. Therefore, we propose that the depletion of histone H1 in bull sperm nuclei is part of nuclear decondensation and swelling that occurs during the remodelling of paternal chromatin after the oocyte fertilization.…”

Section: Discussionsupporting

confidence: 92%

Presence and Release of Bovine Sperm Histone H1 During Chromatin Decondensation by Heparin-Glutathione

Sánchez-Vázquez

Flores-Alonso

Merchant‐Larios

et al. 2008

Systems Biology in Reproductive Medicine

View full text Add to dashboard Cite

During spermatogenesis, changes in sperm nuclear morphology are associated with the replacement of core somatic histones by protamines. Although protamines are the major nucleoproteins of mature sperm, not all species totally replace the histones. Histone H1, along with protamines, mediates chromatin condensation into an insoluble complex that is transcriptionally inactive. In vitro, heparin-reduced glutathione causes sperm decondensation, and the structures formed are morphologically similar to the in vivo male pronucleus. To study the participation of histone H1 in bovine sperm chromatin remodelling, we measured the presence and release of histone H1 by immunofluorescence, acetic acid-urea-triton-polyacrylamide gel electrophoresis, and immunoblotting. Nuclear decondensation was induced by 80 microM heparin and 15.0 mM reduced glutathione (GSH) for 7, 14, and 21 h at 37 degrees C. Additionally, nucleons, composed of nuclei isolated from the sperm, were decondensed with 20.0 microM heparin and 5.0 mM GSH for 4.0 h at 37 degrees C. Controls were incubated in buffer for similar periods of time. Immunofluorescent localization of histone H1 was carried out with mouse monoclonal antibody, and DNA localization was visualized by 0.001% quinacrine staining. Chromatin decondensation was accompanied by increased sperm nuclei and nucleon surface area. We observed that histone H1 was localized exclusively in the nuclei of intact sperm and nucleons. Histone H1 immunofluorescent intensity did not change in control samples but decreased over time in samples treated with heparin-GSH. There was a negative correlation between the surface area of sperm nuclei and immunohistochemical intensity of histone H1 (P < 0.05). Nucleon decondensation showed a similar relationship. By electrophoresis and immunoblotting, we verified the loss of histone H1 from the sperm and nucleons and its release into the incubation media. Based on these results, we propose that histone H1 is present in the bovine sperm nuclei. H1 depletion may participate in chromatin decondensation and nuclear swelling induced by heparin-GSH.

show abstract

Section: Discussionsupporting

confidence: 92%

Presence and Release of Bovine Sperm Histone H1 During Chromatin Decondensation by Heparin-Glutathione

Sánchez-Vázquez

Flores-Alonso

Merchant‐Larios

et al. 2008

Systems Biology in Reproductive Medicine

View full text Add to dashboard Cite

show abstract

“…133 Methods for assessing decondensation must therefore be considered useful for male fertility. Several groups have measured sperm chromatin decondensation by observing changes in size and shape of the sperm head by microscopic examinations when exposed to detergents (mostly sodium dodecylsulphate) and S-S bond reduction (using dithiothreitol), 134,135,136 methods that can predict fertility in vitro. FC offers an excellent possibility to quantity events associated with chromatin decondensation.…”

Section: Changes Induced During Capacitationmentioning

confidence: 99%

Flow cytometry for the assessment of animal sperm integrity and functionality: state of the art

Hossain¹,

Johannisson²,

Wallgren³

et al. 2011

Asian J Androl

143

120

View full text Add to dashboard Cite

Flow cytometry is now a recognized methodology within animal spermatology, and has moved from being a research tool to become routine in the assessment of animal semen destined to breeding. The availability of 'bench-top' flow cytometers and of newer and versatile markers for cell structure and function had allowed the instrumentation to measure more sperm parameters, from viability to reactiveness when exposed to exogenous stimuli, and to increase our capabilities to sort spermatozoa for potential fertilizing capacity, or chromosomal sex. The present review summarizes the state of the art regarding flow cytometry applied to animal andrology, albeit keeping an open comparative intent. It critically evaluates the present and future capabilities of flow cytometry for the diagnostics of potential fertility and for the development of current reproductive technologies such as sperm freezing, sperm selection and sperm sorting. The flow cytometry methods will probably further revolutionize our understanding of the sperm physiology and their functionality, and will undoubtedly extend its application in isolating many uncharacterized features of spermatozoa. However, continuous follow-up of the methods is a necessity owing to technical developments and the complexity of mapping spermatozoa.

show abstract

“…It has been proposed that glutathione, which is present in the egg cytoplasm, provides the reducing equivalents for the reduction of the disulfide bonds [18]. Under in vitro conditions, heparin-reduced glutathione does cause sperm decondensation [22]. The possibility that mitochondria, located in the middle piece of the spermatozoan, might be involved in decondensation via a lactate/pyruvate shuttle system [23] has also been considered.…”

Section: Introductionmentioning

confidence: 99%

Proposed mechanism for sperm chromatin condensation/decondensation in the male rat

Chapman

Michael

2003

Reprod Biol Endocrinol

View full text Add to dashboard Cite

Condensation of sperm chromatin occurs after spermatozoa have left the caput epididymis and are in transit to the cauda epididymis, during which time large numbers of disulfide bonds are formed. The formation of these disulfide bonds requires the repeated oxidation of the cofactor, NAD(P)H. To date, the means by which this oxidation is achieved has yet to be elucidated. Spermatozoa lose the bulk of their cytoplasm prior to leaving the testis; and, as a result, any shuttle systems for removing and transferring reducing equivalents into the mitochondria are unlikely to be operational. In an apparent preparation for the loss of cytoplasm, however, the following events occur during spermatogenesis. First, androgen-binding protein (ABP) is produced by the Sertoli cells of the testis; second, high affinity binding sites for ABP are inserted into the membrane surrounding the nucleus; and third, a nuclear location is acquired for the enzyme, 3α-hydroxysteroid dehydrogenase (3α-HSD).We propose that after the loss of cytoplasm, the nuclear region of spermatozoa is directly accessible to constituents contained in the lumen of the caput epididymis. As a consequence, luminal ABP attaches itself to the nuclear membrane via its binding sites, and is internalized. After internalization, ABP exerts its principle function, which is to bind to luminal 5α-dihydrotestosterone (5α-DHT), thereby ensuring its availability to the enzyme, 3α-HSD. In the conversion of 5α-DHT to 3α-androstanediol (3α-Diol), NAD(P)H is oxidized. Spermatozoa that reach the cauda epididymis have fully condensed chromatin. In addition, the nuclear region retains appreciable amounts of 5α-DHT and 3α-Diol, both bound to ABP. During fertilization, the bound 3α-Diol is converted back to 5α-DHT, reducing equivalents are transferred to NAD(P) + , and disulfide bonds are broken.IVF clinics report that spermatozoa with incompletely condensed chromatin have a low percentage of fertilization. If our proposed mechanism for chromatin condensation/decondensation is borne out by further research, IVF clinics might consider preincubating spermatozoa with 5α-DHT in order to increase the efficiency of fertilization.

show abstract

Effect of Heparin-Reduced Glutathione on Hamster Sperm DNA Unpacking and Nuclear Swelling

Cited by 13 publications

References 46 publications

Presence and Release of Bovine Sperm Histone H1 During Chromatin Decondensation by Heparin-Glutathione

Presence and Release of Bovine Sperm Histone H1 During Chromatin Decondensation by Heparin-Glutathione

Flow cytometry for the assessment of animal sperm integrity and functionality: state of the art

Proposed mechanism for sperm chromatin condensation/decondensation in the male rat

Contact Info

Product

Resources

About