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- Liffner, Susanne, et al.
(författare)
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Diagnostics of DNA fragmentation in human spermatozoa: Are sperm chromatin structure analysis and sperm chromatin dispersion tests (SCD-HaloSpermG2 (R)) comparable?
- 2019
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Ingår i: Andrologia. - : WILEY. - 0303-4569 .- 1439-0272. ; 51:8
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Tidskriftsartikel (refereegranskat)abstract
- Men affected with idiopathic infertility often display basic spermiogramme values similar to fertile individuals, questioning the diagnostic impact of the World Health Organization (WHO) thresholds used. This study explored sperm DNA fragmentation in single ejaculates from 14 fertile donors and 42 patients with idiopathic infertility providing semen for assisted reproductive techniques in a university fertility clinic. Each ejaculate was simultaneously studied for sperm DNA fragmentation by the flow cytometer-based sperm chromatin structure analysis (SCSA) and the new light-microscopy-based sperm chromatin dispersion assay (SCD-HaloSpermG2 (R)), before and after sperm selection for in vitro fertilisation with a colloid discontinuous gradient. The WHO semen variables did not differ between groups, but DNA fragmentation after SCSA (DFI) or SCD (SDF) was significantly (p amp;lt; 0.05) higher in patients (DFI: 40.2% +/- 3.0 vs. SDF: 40.3% +/- 1.4) than in fertile donors (DFI: 17.1% +/- 2.1 vs. SDF: 20.9% +/- 2.5). Sperm selection led to lower proportions of DNA-fragmented spermatozoa (DFI: 11.9 +/- 1.7 vs. SCD: 10.0 +/- 0.9, p amp;lt; 0.05). The techniques output correlated highly and significantly (r(2) = 0.82). DNA fragmentation is confirmed as a relevant variable for scrutinising patients with idiopathic infertility, beyond the evidently insufficient WHO semen analyses. Since both techniques yielded similar results, the reduced necessity of complex equipment when running SCD ought to be considered for a clinical setting.
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| 2. |
- Nätt, Daniel, et al.
(författare)
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Human sperm displays rapid responses to diet
- 2019
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Ingår i: PLoS biology. - San Francisco, CA United States : PUBLIC LIBRARY SCIENCE. - 1544-9173 .- 1545-7885. ; 17:12
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Tidskriftsartikel (refereegranskat)abstract
- The global rise in obesity and steady decline in sperm quality are two alarming trends that have emerged during recent decades. In parallel, evidence from model organisms shows that paternal diet can affect offspring metabolic health in a process involving sperm tRNA-derived small RNA (tsRNA). Here, we report that human sperm are acutely sensitive to nutrient flux, both in terms of sperm motility and changes in sperm tsRNA. Over the course of a 2-week diet intervention, in which we first introduced a healthy diet followed by a diet rich in sugar, sperm motility increased and stabilized at high levels. Small RNA-seq on repeatedly sampled sperm from the same individuals revealed that tsRNAs were up-regulated by eating a high-sugar diet for just 1 week. Unsupervised clustering identified two independent pathways for the biogenesis of these tsRNAs: one involving a novel class of fragments with specific cleavage in the T-loop of mature nuclear tRNAs and the other exclusively involving mitochondrial tsRNAs. Mitochondrial involvement was further supported by a similar up-regulation of mitochondrial rRNA-derived small RNA (rsRNA). Notably, the changes in sugar-sensitive tsRNA were positively associated with simultaneous changes in sperm motility and negatively associated with obesity in an independent clinical cohort. This rapid response to a dietary intervention on tsRNA in human sperm is attuned with the paternal intergenerational metabolic responses found in model organisms. More importantly, our findings suggest shared diet-sensitive mechanisms between sperm motility and the biogenesis of tsRNA, which provide novel insights about the interplay between nutrition and male reproductive health.
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