Sperm-borne sncRNAs: potential biomarkers for semen fertility?

Abstract

Semen infertility or sub-fertility, whether in humans or livestock species, remains a major concern for clinicians and technicians involved in reproduction. Indeed, they can cause tragedies in human relationships or have a dramatic overall negative impact on the sustainability of livestock breeding. Understanding and predicting semen fertility issues is therefore crucial and quality control procedures as well as biomarkers have been proposed to ensure sperm fertility. However, their predictive values appeared to be too limited and additional relevant biomarkers are still required to diagnose sub-fertility efficiently. During the last decade, the study of molecular mechanisms involved in spermatogenesis and sperm maturation highlighted the regulatory role of a variety of small non-coding RNAs (sncRNAs) and led to the discovery that sperm sncRNAs comprise both remnants from spermatogenesis and post-testicular sncRNAs acquired through interactions with extracellular vesicles along epididymis. This has led to the hypothesis that sncRNAs may be a source of relevant biomarkers, associated either with sperm functionality or embryo development. This review aims at providing a synthetic overview of the current state of knowledge regarding implication of sncRNA in spermatogenesis defects and their putative roles in sperm maturation and embryo development, as well as exploring their use as fertility biomarkers.

Small Non-Coding RNAs in Male Reproduction

“…Several studies have been conducted to identify differences in the levels of specific types of sperm sncRNAs in sub/infertile versus fertile men. 8 For example, miR-34b/c and miR-449a that are specifically expressed during late phases of spermatogenesis and required for normal production of sperm 57 148 have been reported to have reduced levels in subfertile individuals and infertile patients associated with spermatogenic failure. 149 Other sncRNA classes in addition to miRNAs have also been analyzed, for example, some differentially expressed individual piRNAs have been identified in the sperm samples of asthenozoospermic or oligospermic patients compared to the normozoospermic controls.…”

“…6 Considering the association of aberrant expression of sncRNAs with abnormal sperm production, sncRNAs have clinical relevance as potential indicators or biomarkers of male subfertility/infertility and other disorders of male reproductive health. 7,8 In addition, cumulative Keywords ► small non-coding RNA ► miRNA ► piRNA ► male germline ► sperm ► fertility…”

“…6 Considering the association of aberrant expression of sncRNAs with abnormal sperm production, sncRNAs have clinical relevance as potential indicators or biomarkers of male subfertility/infertility and other disorders of male reproductive health. 7 8 In addition, cumulative evidence shows that sperm sncRNAs can transmit epigenetic information on father's acquired conditions such as metabolic or psychiatric disorders to the offspring; therefore, they not only contribute to male reproductive health but also play a role in the health of the offspring. 9 This further highlights the significance of understanding sncRNA functions in the germline to improve human health.…”

Effects of Feeding 60% Dried Corn Distillers’ Grains or the Equivalent Sulfur as CaSO4 on DNA Integrity and Gene Expression in Yearling Angus Bull Sperm

“…This gene codes the signal recognition particle (SRP) required for co-translational regulation [33]. It has been suggested that rRNAs interact with argonaut (AGO) proteins and potentially silence target genes [34].…”

Multi-omics data integration for the identification of biomarkers for bull fertility

“…However, the levels of predictive accuracy achieved during these studies were insufficient [2][3][4][5][6][7]. As well as genetics and semen parameters, a broad range of epigenetic mechanisms such as DNA methylation, sncRNAs and the ratio between histones and protamines also contribute to male fertility [7][8][9][10][11]. For this reason, epigenetic studies have been the subject of increasing attention in recent years in the context of male fertility, and encouraging results have been obtained [12][13][14][15][16][17][18][19].…”