Sperm mRNAs and microRNAs as candidate markers for the impact of toxicants on human spermatogenesis: an application to tobacco smoking

Abstract

Spermatozoa contain a complex population of RNAs including messenger RNAs (mRNAs) and small RNAs such as microRNAs (miRNA). It has been reported that these RNAs can be used to understand the mechanisms by which toxicological exposure affects spermatogenesis. The aim of our study was to compare mRNA and miRNA profiles in spermatozoa from eight smokers and eight non-smokers, and search for potential relationships between mRNA and miRNA variation. All men were selected based on their answers to a standard toxic exposure questionnaire, and sperm parameters. Using mRNA and miRNA microarrays, we showed that mRNAs from 15 genes were differentially represented between smokers and non-smokers (p < 0.01): five had higher levels and 10 lower levels in the smokers. For the microRNAs, 23 were differentially represented: 16 were higher and seven lower in the smokers (0.004 ≤ p < 0.01). Quantitative RT-PCR confirmed the lower levels in smokers compared to non-smokers for hsa-miR-296-5p, hsa-miR-3940, and hsa-miR-520d-3p. Moreover, we observed an inverse relationship between the levels of microRNAs and six potential target mRNAs (B3GAT3, HNRNPL, OASL, ODZ3, CNGB1, and PKD2). Our results indicate that alterations in the level of a small number of microRNAs in response to smoking may contribute to changes in mRNA expression in smokers. We conclude that large-scale analysis of spermatozoa RNAs can be used to help understand the mechanisms by which human spermatogenesis responds to toxic substances including those in tobacco smoke.

• Human
• miRNA
• mRNA
• spermatogenesis
• spermatozoa
• tobacco

Acknowledgments

We are grateful to the patients who gave their informed consent for the use of their samples for research. We thank C. Metton and M.J. Fays-Bernardin for technical assistance and Germetheque support. We also thank M. Mitchell for the text revision, and M. Guichaoua for her precious advise.

Declaration of interest

This work was supported by grants from INSERM: Institut National de la Santé Et de la Recherche Médicale and APHM: Assistance Publique – Hôpitaux de Marseille. The Germetheque biobank was supported by grants from the ANR (Agence Nationale de la Recherche), the Agence de la biomedicine, the Centre Hospitalier Universitaire de Toulouse, and APHM (Assistance Publique Hôpitaux de Marseille). All authors declare no declarations of interest and no competing financial interest.

Author contributions

Played a role in the sample collection, the biological experiments, the study design and the manuscript writing: CMG. Had a major role in the bioinformatics data analysis: CL, AB, PR. In charge of microarray and quantitative PCR experiments: GV, MY, NB. Played a role in the patient recruitment: JP, ISM. Direct responsibility for the manuscript: CN, PR. All authors contributed to the writing and revision of the manuscript.

Supplementary material available online Supplementary Figures