Sperm nuclear DNA fragmentation rate is associated with differential protein expression and enriched functions in human seminal plasma

Authors


Correspondence: Paula Intasqui, Sao Paulo Federal University, R Embau, 231, Sao Paulo, SP 04039-060, Brazil.

e-mail: paula.intasqui@gmail.com

Abstract

Objective

  • To analyse the proteomic profile of seminal plasma with the aim of identifying the proteins and post-genomic pathways associated with sperm DNA fragmentation.

Materials and Methods

  • A cross-sectional study including 89 subjects from a human reproduction service was carried out.
  • All semen samples were assessed for sperm DNA fragmentation using a comet assay.
  • Results from 60 sperm were analysed using Komet 6.0.1 software and the ‘Olive tail moment’ variable was used to stratify these into low and high sperm DNA fragmentation groups.
  • Seminal plasma proteins from the two groups were pooled and used for proteomic analysis.
  • Quantitative data were used for functional enrichment studies.

Results

  • Seventy-two proteins were identified or quantified in seminal plasma. Of these, nine were differentially expressed in the low group and 21 in the high group. Forty-two proteins were conserved between these groups.
  • Functional enrichment analysis indicated that sperm DNA fragmentation was related to functions such as lipoprotein particle remodelling and regulation, fatty acid binding and immune response.
  • Proteins found exclusively in the low group may be involved in correcting spermatogenesis and/or improving sperm function. Proteins in the high group were associated with increased innate immune response, sperm motility and/or maturation and inhibition of mitochondrial apoptosis.

Conclusion

  • Protein expression and post-genomic pathways of seminal plasma differ according to the rate of sperm DNA integrity.

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