Unraveling the sperm proteome and post-genomic pathways associated with sperm nuclear DNA fragmentation

Abstract

Purpose Sperm DNA fragmentation has been suggested as a marker for infertility diagnosis and prognosis. Hence, understanding its impact on male physiology and post-genomic pathways would be clinically important. We performed the proteomics and functional enrichment analyses of viable spermatozoa from ejaculates with low and high sperm DNA fragmentation to identify protein expression and pathways altered in association with sperm DNA fragmentation. Methods Sperm DNA fragmentation using the Comet assay and the Komet 6.0.1 software was assessed in raw samples from 89 subjects from a human reproduction service. The Low and High sperm DNA fragmentation groups were formed according to the Olive Tail Moment variable. Spermatozoa proteins from these groups were pooled and analyzed by a shotgun proteomic approach (2D nanoUPLC-ESI-MS E ). Differentially expressed proteins were used for a functional enrichment study. Results Two hundred and fifty-seven proteins were identified or quantified in sperm from the Low and High sperm DNA fragmentation groups. Of these, seventy-one proteins were exclusively or overexpressed in the Low group, whereas twenty-three proteins were exclusively or overexpressed in the High group. One hundred and sixty-three proteins were conserved between these groups. We also functionally related the differentially expressed proteins in viable spermatozoa from the groups. Processes such as triacylglycerol metabolism, energy production, protein folding, response to unfolded proteins, and cellular detoxification were found to be altered in these cells. Conclusions Sperm DNA fragmentation is associated with differential protein expression in viable spermatozoa. These proteins may potentially be used as biomarkers for sperm DNA integrity.

Markers for Sperm Freezability and Relevance of Transcriptome Studies in Semen Cryopreservation: A Review

“…These DNA integrity assays have conirmed that the cryopreservation process increases the sperm susceptibility to DNA damage, irrespective of the extender or the protocol type [4,5,8,21,24,32,34,35]. It is worth noting that sperm DNA fragmentation is associated with diferential expression of proteins in the viable sperm populations [36]. Intasqui et al [36] postulated that the overexpression of the sperm proteins in the viable sperm population from ejaculates with high-sperm DNA fragmentation might indicate proteome alterations to compensate defects in sperm motility.…”

“…The ODF2 seems to be essential to ODF assembly, and its overexpression in frozen-thawed boar spermatozoa was associated with reduced post-thaw semen quality [40]. Moreover, AKAP4 and AKAP3 occur in the ibrous sheath of sperm lagellum and are involved in sperm motility and morphology [36]. It has been conirmed that an increase in the expression of either AKAP4 or AKAP3 in frozen-thawed spermatozoa might be associated with their premature capacitation [40].…”

“…It is worth noting that sperm DNA fragmentation is associated with diferential expression of proteins in the viable sperm populations [36]. Intasqui et al [36] postulated that the overexpression of the sperm proteins in the viable sperm population from ejaculates with high-sperm DNA fragmentation might indicate proteome alterations to compensate defects in sperm motility.…”

“…In boar sperm extracts, the levels of outer dense iber 2 (ODF2), A-kinase-anchoring protein 3 or 4 (AKAP3; AKAP4), heatshock protein 90 (HSP90AA1), voltage-dependent anion channel 2 (VDAC2), acrosin-binding protein (ACRBP), and triosephosphate isomerase 1 (TP1) activities were associated with semen freezability [10,40]. Furthermore, ODFs provide a stable and elastic structure to the lagellum of the spermatozoon, supporting its movement and protecting it during the epididymal transit and ejaculation [36,39,40]. The ODF2 seems to be essential to ODF assembly, and its overexpression in frozen-thawed boar spermatozoa was associated with reduced post-thaw semen quality [40].…”

Estrés oxidativo: ¿un estado celular defectuoso para la función espermática?

“…El eyaculado contiene muchas proteínas de importancia para la fecundación, por lo que algunos estudios se han encargado de comparar su composición entre individuos fértiles e infértiles con el objetivo de caracterizarlo (62,63) y asociarlo con la movilidad y la calidad del ADN espermático (64). En el plasma seminal se encuentra una cantidad de antioxidantes, principalmente extracelulares, tanto enzimáticos como no enzimáticos (1), entre los que se incluyen la catalasa, la superóxido dismutasa y el glutatión.…”