Sperm proteomic changes associated to early embryo quality after ICSI

Abstract Research Question Do alterations of human sperm protein profile affect embryo quality? Design The sperm proteins from 27 infertile couples undergoing ICSI were extracted and digested. The resulting peptides were labeled using tandem mass tags (TMT), separated by two-dimensional liquid chromatography (2D-LC), and identified and quantified using tandem mass spectrometry (MS/MS). Subsequently, sperm protein and peptide abundance were correlated with the quality of the ICSI-derived embryos in the subset of idiopathic infertile couples. Finally, these detected correlations were further assessed in the subset of infertile patients with a known factor. Results The abundance of 18 sperm proteins were correlated with embryo quality after ICSI. Remarkably, a high percentage of poor-quality ICSI-derived embryos was associated with the alteration of the chaperonin TCP-1 ring complex, which plays an important role in the folding of many essential proteins. Additionally, the abundance of sperm proteins with a known function in embryogenesis, such as RUBVL1, were also correlated with early embryo quality. Some of the correlations found in this study were validated by using either proteomic data from the infertile patients with a known factor or data from similar published studies. Interestingly, the analysis at the peptide level revealed the association of some correlations with specific post-translational modifications or isoforms. Conclusions Our results support the hypothesis that the sperm proteome plays a role in early embryogenesis. Moreover, several sperm proteins have emerged as potential biomarkers to predict in vitro assisted reproductive technologies (ART) outcome, leading to the possibility to be further developed to improve the diagnostic of idiopathic infertile couples.