Molecular characterization of seminal extracellular vesicles, spermatozoa and seminal plasma in varicocele and its association with seminal inflammatory aspects

Abstract

Varicocele decreases the seminal and functional quality of sperm and the proteome profile of seminal plasma, for example, we observed an increase in the levels of inflammatory proteins. It is essential to understand the intrinsic mechanisms of transfer and regulation of protein expression present in semen, in addition to establishing inflammatory patterns. Spermatozoa are exposed to extracellular vesicles (EV) during epididymal transit and after ejaculation. EV have their own protein composition, which may be essential for the transport and transfer of proteins and microRNAs and play important roles in spermatozoa, including control of the translation of messenger RNA into proteins. Therefore, the hypotheses of the present project are: varicocele determines changes in seminal inflammatory pathways, the expression of regulatory microRNAs observed in semen, the composition of proteins secreted apocrically in seminal plasma (as EV). In order to verify our hypothesis, the main objective of this project is to study seminal inflammatory aspects and their role in varicocele. To do this we will have four study groups (n=50/group): (i) Men without varicocele (control), (ii) With varicocele and normal semen, and (iii) With varicocele and altered semen. In these groups, we will verify inflammatory protein pathways in seminal plasma, using a multiplex analysis (MAGPIX - Millipore), the study of miRNA of seminal plasma and spermatozoa will be carried out using the Next generation sequencing technique and the microRNAs found to be related to inflammation will undergo a confirmatory analysis by qRT-PCR. We will also study the proteome of EV in seminal plasma and sperm by mass spectrometry using a gel-free label-free approach. With the results of the present project, we intend to generate knowledge about altered proteomic pathways in male infertility (to be added to that generated by previous studies). (AU)