Was gibt es Neues zum Thema der DNA Fragmentierung der Spermien ! 04.2010
Wir haben für Sie zum Thema DNA-Fragmentierung bei Spermien die neuesten Veröffentlichungen der letzten zwei Monate zusammengestellt. Die Vielzahl der Publikationen steht für die Aktualität der Thematik.
Die wichtigsten Aussagen werden für jeden Bericht kurz zusammengefasst. Sie können sich den vollständigen Abstract von PubMed hier herunterladen.
Folgende Themen werden besprochen:
- DNA Fragmentierung der Spermien und klinische Ergebnisse.
- DNA Fragmentierung der Spermien in Korrelation zu iatrogenen Schädigungen und zur Methode der Spermienaufbereitung.
- Welche äusseren Ursachen führen zur DNA Fragmentierung der Spermien?
- DNA Fragmentierung und oxidativer Stress.
- Selektion von Spermatozoen ohne DNA Fragmentierung.
1. DNA Fragmentierung der Spermien und klinische Ergebnisse.
Barratt, C.L., Aitken, R.J., Bjorndahl, L., Carrell, D.T., de Boer, P., Kvist, U., Lewis, S.E., Perreault, S.D., Perry, M.J., Ramos, L., et al. (2010).
"Sperm DNA: organization, protection and vulnerability: from basic science to clinical applications--a position report." Hum Reprod.
This article reports the results of the most recent in a series of EHSRE workshops designed to synthesize the current state of the field in Andrology and provide recommendations for future work. The document presents a synthesis of the working group’s understanding of the recent literature and collective discussions on the current state of knowledge of sperm chromatin structure and function during fertilization. It highlights the biological, assay and clinical uncertainties that require further research.
Berlinguer, F., Madeddu, M., Pasciu, V., Succu, S., Spezzigu, A., Satta, V., Mereu, P., Leoni, G.G., and Naitana, S. (2009).
"Semen molecular and cellular features: these parameters can reliably predict subsequent ART outcome in a goat model." Reprod Biol Endocrinol 7, 125.
Using a goat model the authors show that sperm DNA fragmentation has a high predictive value in IVF outcome. The model proposed represents one of the ways to explain the differences found in embryo output following IVF with different semen donors and may represent a useful tool to select the most suitable donors from semen cryopreservation.
2. DNA Fragmentierung der Spermien in Korrelation zu iatrogenen Schädigungen und zur Methode der Spermienaufbereitung.
Koderle, M., Aurich, C., and Schafer-Somi, S. (2009).
„The influence of cryopreservation and seminal plasma on the chromatin structure of dog spermatozoa.“ Theriogenology 72, 1215-1220.
The results of this study show that centrifugation to remove seminal plasma before cryopreservation negatively affected post-thaw motility, the percentage of morphologically abnormal spermatozoa and the percentage of spermatozoa with fragmented DNA.
Ahmad, L., Jalali, S., Shami, S.A., Akram, Z., Batool, S., and Kalsoom, O. (2010).
„Effects of cryopreservation on sperm DNA integrity in normospermic and four categories of infertile males.“ Syst Biol Reprod Med 56, 74-83.
Cryopreservation caused less DNA damage in semen samples prepared using the Percoll density gradient centrifugation method compared to those prepared by swim-up or neat samples.
Semen from fertile patients and normospermic samples from infertile patients showed less sperm DNA fragmentation than teratospermic and asthenoteratozoospermic individuals.
Gosalvez, J., de la Torre, J., Lopez-Fernandez, C., Perez-Gutierrez, L., Ortega, L., Caballero, P., and Nunez, R. (2010).
„DNA fragmentation dynamics in fresh versus frozen thawed plus gradient-isolated human spermatozoa.“ Syst Biol Reprod Med 56, 27-36.
This study compared the rate of sperm DNA fragmentation over a 72 hour period in fresh samples and those that have undergone density-gradient purification followed by freeze-thawing. Manipulation of the sample reduced the variability of sperm DNA fragmentation in the population of samples studied.
This manipulation had variable effects on the levels and rate of fragmentation from one individual to another.
Perez-Llano, B., Lopez-Fernandez, C., Garcia-Casado, P., Arroyo, F., Gosalbez, A., Sala, R., and Gosalvez, J. (2010).
„Dynamics of sperm DNA fragmentation in the swine: Ejaculate and temperature effects.“ Anim Reprod Sci.
The dynamics of sperm DNA fragmentation were measured in boar ejaculates. In some ejaculates no rise in DNA fragmentation was observed, whereas in others, the sperm DNA fragmentation process was triggered during the initial days of the experiment. Storage of the samples at 37°C diminished sperm DNA quality compared to storage at 15°C.
A two-tail comet assay indicated that at time zero existing DNA damage mainly consisted of double stranded DNA breakage. During storage, DNA damage affected one of the DNA strands until a second wave of DNA damage, in which there was both single and double stranded DNA damage.
3. Welche äusseren Ursachen führen zur DNA Fragmentierung der Spermien?
Calogero, A., Polosa, R., Perdichizzi, A., Guarino, F., La Vignera, S., Scarfia, A., Fratantonio, E., Condorelli, R., Bonanno, O., Barone, N., et al. (2009).
„Cigarette smoke extract immobilizes human spermatozoa and induces sperm apoptosis.“ Reprod Biomed Online 19, 564-571.
Spermatozoa from healthy, non-smoking men with normal semen parameters were subjected to graded concentrations of cigarette smoke extract. This caused a suppression of sperm motility, increased the number of spermatozoa with mitochondrial membrane potential and increased the number of spermatozoa with sperm DNA fragmentation.
Du Plessis, S.S., Cabler, S., McAlister, D.A., Sabanegh, E., and Agarwal, A. (2010).
„The effect of obesity on sperm disorders and male infertility.“ Nat Rev Urol.
Review article that summarizes the results of several studies for the cause of infertility in overweight men. One of the explanations highlighted is that obesity causes increased scrotal temperatures that ultimately cause an increase in DNA fragmentation and impairment of other semen parameters.
Hourcade, J.D., Perez-Crespo, M., Fernandez-Gonzalez, R., Pintado, B., and Gutierrez-Adan, A. (2010).
„Selection against spermatozoa with fragmented DNA after postovulatory mating depends on the type of damage.“ Reprod Biol Endocrinol 8, 9.
This study, conducted in an animal model, suggests that in postovulatory mating there is a preliminary general selection mechanism against spermatozoa with low motility and fragmented DNA during the transport through the female reproductive tract and in zona pellucida binding.
The ability of the zona pellucida to prevent fertilization by spermatozoa with fragmented DNA depends on the source of DNA damage. In this case, the zona pellucida was able to prevent fertilization by spermatozoa with fragmented DNA when the damage was induced by scrotal heat stress but not when induced by radiation with gamma rays.
Sakkas, D., and Alvarez, J.G. (2010).
„Sperm DNA fragmentation: mechanisms of origin, impact on reproductive outcome, and analysis.“ Fertil Steril 93, 1027-1036.
Review article that summarizes the mechanisms responsible for DNA fragmentation and the impact that this parameter has on clinical outcome of assisted reproduction.
Zini, A., Azhar, R., Baazeem, A., and Gabriel, M.S. (2010).
„Effect of microsurgical varicocelectomy on human sperm chromatin and DNA integrity: a prospective trial.“ Int J Androl.
This article shows that sperm DNA fragmentation decreases significantly following varicocelectomy.
4. DNA Fragmentierung und oxidativer Stress.
Libman, J., Gabriel, M.S., Sairam, M.R., and Zini, A. (2010).
„Catalase can protect spermatozoa of FSH receptor knock-out mice against oxidant-induced DNA damage in vitro.“ Int J Androl.
The objective of this study was to investigate the susceptibility of spermatozoa to oxidative damage and the protective effect of the antioxidant catalase in wild-type and FSH receptor knock-out mice. In the knock-out mice, catalase protected spermatozoa from DNA damage.
Mahfouz, R., Sharma, R., Thiyagarajan, A., Kale, V., Gupta, S., Sabanegh, E., and Agarwal, A. (2010).
„Semen characteristics and sperm DNA fragmentation in infertile men with low and high levels of seminal reactive oxygen species.“ Fertil Steril.
The objective of this study was to investigate the semen characteristics in infertile men with high levels of reactive oxygen species. These patients showed higher levels of sperm DNA fragmentation, poorer motility, and a higher incidence of leukocytospermia that controls.
Santiso, R., Tamayo, M., Gosalvez, J., Meseguer, M., Garrido, N., and Fernandez, J.L. (2010).
"Simultaneous determination in situ of DNA fragmentation and 8-oxoguanine in human sperm." Fertil Steril 93, 314-318.
In this study, DNA fragmentation and oxidative DNA damage were simultaneously determined in the same sperm cell. In all samples examined, increased levels of 8-oxoguanine (the marker for oxidative DNA damage) were only present in those spermatozoa with fragmented DNA, suggesting a link between both types of damage.
Tremellen, K., and Tunc, O. (2010).
„Macrophage activity in semen is significantly correlated with sperm quality in infertile men.“ Int J Androl.
In this study the authors measured the levels of semen neopterin, a molecule released from activated macrophages, as a marker for macrophage activity in the male reproductive tract. Such activity is known to cause sperm DNA damage through the generation of reactive oxygen species. Increased levels of neopterin were found in asymptomatic subjects with male factor infertility compared to fertile control patients. Furthermore, seminal plasma neopterin concentration was significantly correlated with sperm oxidative stress, DNA fragmentation and apoptosis.
5. Selektion von Spermatozoen ohne DNA Fragmentierung.
Lee, T.H., Liu, C.H., Shih, Y.T., Tsao, H.M., Huang, C.C., Chen, H.H., and Lee, M.S. (2010).
„Magnetic-activated cell sorting for sperm preparation reduces spermatozoa with apoptotic markers and improves the acrosome reaction in couples with unexplained infertility.“ Hum Reprod.
This study investigated the effect of magnetic-activated cell sorting (MACS) on semen collected from couples with unexplained infertility. This technique significantly reduced apoptotic markers including sperm DNA fragmentation. After MACS the spermatozoa also responded significantly better in the induced acrosome reaction test suggesting a higher fertilization potential than controls.
Polak de Fried, E., and Denaday, F. (2010).
„Single and twin ongoing pregnancies in two cases of previous ART failure after ICSI performed with sperm sorted using annexin V microbeads.“ Fertil Steril.
This paper describes two successful case studies of couples treated by intracytoplasmic sperm injection following annexin V sperm sorting. In one case, the male was diagnosed with asthenoteratozoospermia and elevated sperm DNA fragmentation levels. In the other case, the male was diagnosed with teratozoospermia and abnormal caspase-3.
Rawe, V.Y., Boudri, H.U., Sedo, C.A., Carro, M., Papier, S., and Nodar, F. (2010).
„Healthy baby born after reduction of sperm DNA fragmentation using cell sorting before ICSI.“ Reprod Biomed Online 20, 320-323.
This paper describes the successful case study of a couple treated by intracytoplasmic sperm injection following magnetic-activated cell sorting with annexin V microbeads. In this case, sperm DNA fragmentation was significantly reduced after sorting.
Tarozzi, N., Nadalini, M., Bizzaro, D., Serrao, L., Fava, L., Scaravelli, G., and Borini, A. (2009).
"Sperm-hyaluronan-binding assay: clinical value in conventional IVF under Italian law." Reprod Biomed Online 19 Suppl 3, 35-43.
This study demonstrates that the sperm hyaluronan-binding assay is able to select a population of spermatozoa with significantly reduced DNA fragmentation. However, the authors observed no correlation between hyaluronan binding and fertilization, cleavage, good-quality embryos, implantation, clinical pregnancy, miscarriages and biochemical pregnancy rates.
Yagci, A., Murk, W., Stronk, J., and Huszar, G. (2010).
Spermatozoa Bound to Solid State Hyaluronic Acid Show Chromatin Structure with High DNA Chain Integrity: An Acridine Orange Fluorescence Study. J Androl.
This study demonstrates that sperm cells that have the ability to bind to hyaluronic acid have lower sperm DNA fragmentation.
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