Sperm DNA fragmentation and oxidation are independent of malondialdheyde

Abstract

BackgroundThere is clinical evidence to show that sperm DNA damage could be a marker of sperm quality and extensive data exist on the relationship between DNA damage and male fertility status. Detecting such damage in sperm could provide new elements besides semen parameters in diagnosing male infertility. We aimed to assess sperm DNA fragmentation and oxidation and to study the association between these two markers, routine semen parameters and malondialdehyde formation.MethodsSemen samples from 55 men attending the Histology-Embryology Laboratory of Sfax Faculty of Medicine, Tunisia, for semen investigations were analysed for sperm DNA fragmentation and oxidation using flow cytometry. The Sperm was also assessed spectrophotometrically for malondialdehyde formation.ResultsWithin the studied group, 21 patients were nonasthenozoospermic (sperm motility ≥ 50%) and 34 patients were considered asthenozoospermic (sperm motility < 50%). A positive correlation was found between sperm DNA fragmentation and oxidation (p = 0.01; r = 0.33). We also found a negative correlation between sperm DNA fragmentation and some sperm parameters: total motility (p = 0.001; r = -0.43), rapid progressive motility (type a motility) (p = 0.04; r = -0.27), slow progressive motility (type b motility) (p = 0.03; r = -0.28), and vitality (p < 0.001; r = -0.65). Sperm DNA fragmentation was positively correlated with coiled tail (p = 0.01; r = 0.34). The two parameters that were found to be correlated with oxidative DNA damage were leucocytes concentrations (p = 0.01; r = 0.38) and broken neck (p = 0.02; r = 0.29). Sperm MDA levels were negatively correlated with sperm concentration (p < 0.001; r = -0.57), total motility (p = 0.01; r = -0.35) and type a motility (p = 0.03; r = -0.32); but not correlated with DNA fragmentation and DNA oxidation.ConclusionsOur results support the evidence that oxidative stress plays a key role in inducing DNA damage; but nuclear alterations and malondialdehyde don't seem to be synchronous.

Development of a specific method to evaluate 8-hydroxy,2-deoxyguanosine in sperm nuclei: relationship with semen quality in a cohort of 94 subjects

“…the malondialdehyde in the semen of a group of patients similar to this study. Intriguingly, in the study by Zribi et al (2011), sperm levels of spermatozoa were associated with poor sperm motility whereas those of 8-OHdG were not.…”

“…Although we cannot exclude that, in the current commercial kits, avidin has been engineered to reduce the non-specific binding (Takakura et al 2012), in our hands, the co-incubation of BP-F with 8-OHdG did not result in a decrease of the fluorescence signal to sperm nuclei. It is possible that, at variance with DNA macromolecules and cultured somatic cells (employed in the study by Struthers et al (1998)), in the highly compacted sperm chromatin, the specific binding between BP-F and 8-OHdG, if any, is masked by the fluorescence due to non-specific interactions and/or that it can be unmasked only when chromatin is heavily oxidized as in the cases of treatment with huge concentrations of H 2 O 2 (Zribi et al 2011) or Fenton reaction induction ). In line with this conclusion is the finding (Zribi et al 2011) that the amount of 8-OHdG assessed by the oxyDNA kit does not associate with that of another marker of OS, i.e.…”

“…It is possible that, at variance with DNA macromolecules and cultured somatic cells (employed in the study by Struthers et al (1998)), in the highly compacted sperm chromatin, the specific binding between BP-F and 8-OHdG, if any, is masked by the fluorescence due to non-specific interactions and/or that it can be unmasked only when chromatin is heavily oxidized as in the cases of treatment with huge concentrations of H 2 O 2 (Zribi et al 2011) or Fenton reaction induction ). In line with this conclusion is the finding (Zribi et al 2011) that the amount of 8-OHdG assessed by the oxyDNA kit does not associate with that of another marker of OS, i.e. the malondialdehyde in the semen of a group of patients similar to this study.…”

“…Furthermore a negative correlation between sperm count/density and OS was observed in some reports (Ni et al 1997, Shen et al 1999, however failing to reveal a relationship with motility (Shen et al 1999) and motility and morphology (Ni et al 1997). Finally, some authors found no correlation between oxidative damage and semen quality , Montjean et al 2010, Zribi et al 2011. These discrepancies may originate from the use of different techniques, and/or targets, to reveal OS in semen.…”

Effects of reduced seminal enzymatic antioxidants on sperm DNA fragmentation and semen quality of Tunisian infertile men

“…Recently, sperm DNA integrity has been regarded as a more accurate and precise biologic marker of male fertility since an intact DNA is necessary for the correct transmission of genetic material to the next generation [40]. It is well known that DNA damage in spermatozoa, characterized by single or double stranded DNA breaks/fragmentation, occurs during late spermatogenesis as a consequence of endogenous factors present in the testis/epididymis, or due to exogenous factors present after ejaculation [21,30].…”