Oral Presentation ESA-SRB-ANZOS 2025 in conjunction with ENSA

Advancing understanding of the protein composition of human seminal extracellular vesicles (128630)

Cottrell T Tamessar 1 2 3 , Shanu Parameswaran 1 2 , Elizabeth Torres-Arce 1 2 , Judith Weidenhofer 4 5 , Hui-Ming Zhang 6 , Jessica E Mulhall 1 2 , Sarah A Robertson 7 , Elizabeth G Bromfield 1 2 8 , Brett Nixon 1 2 , David J Sharkey 7 , David A Skerrett-Byrne 2 9 10 11 , John E Schjenken 1 2
  1. Centre for Reproductive Science, School of Environmental and Life Sciences, College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW, Australia
  2. Hunter Medical Research Institute, Infertility and Reproduction Research Program, New Lambton Heights, New South Wales, Australia
  3. Systems Biology Research Center, School of Bioscience, University of Skovde, Skovde, Sweden
  4. School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, University of Newcastle, Ourimbah, New South Wales, Australia
  5. Hunter Medical Research Institute, Precision Medicine Research Program, New Lambton Heights, New South Wales, Australia
  6. Central Analytical Facility, Research and Innovation division, University of Newcastle, Callaghan, NSW, Australia
  7. The Robinson Research Institute and School of Biomedicine, University of Adelaide, Adelaide, South Australia, Australia
  8. School of Biosciences, Faculty of Science, Bio21 Institute, The University of Melbourne, Parkville, Victoria, Australia
  9. School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, University of Newcastle, Callaghan, NSW, Australia
  10. Institute of Experimental Genetics, German Research Centre for Environmental Health, Helmholtz Zentrum Munchen, Neuherberg, Germany
  11. German Centre for Diabetes Research (DZD), Neuherberg, Germany

Seminal extracellular vesicles (SEVs) carry a diverse array of bioactive molecules, including proteins, lipids, and nucleic acids, which influence sperm function and are implicated in modulating the female reproductive tract immune response after intromission. However, the full spectrum of SEV cargo involved in these processes remains incompletely defined. Here, we employed label-free quantitative high-resolution mass spectrometry to characterize the human SEV proteome, identifying 5,079 associated proteins. As the male reproductive tract origins of SEVs are still poorly understood, we first used the Human Protein Atlas Tissue Based Map of the Human Proteome to predict the male reproductive tract origin of the top 20 most abundant proteins. SEV proteins were thereby categorised as seminal vesicle-enriched (5/20 proteins), prostate-enriched (3/20 proteins), or no specific tissue enrichment (12/20 proteins) providing compelling evidence that in addition to the prostate, the seminal vesicles are a major contributor to the SEV pool. To explore the functions of SEV proteins, bioinformatic analysis using Ingenuity Pathway Analysis revealed enrichment in sperm- and immune-related functions, consistent with the predicted roles of SEV in events surrounding conception. Notably, we identified several proteins with established roles in sperm physiology and immune signalling that had not previously been postulated to be SEV signalling mediators. These included; Adenylate kinase isoenzyme (AK)2/9, calcium-binding tyrosine-phosphorylation regulated protein (CABYR), implicated in sperm motility, and immune regulators such as the toll-like receptor 4 ligand, high mobility group protein B1 (HMGB1), and the nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) inhibitor epsilon (NFκBIE). Interestingly, many other SEV proteins were associated with protein translation functions, potentially contributing to sperm survival and function in the female reproductive tract. Altogether, these findings expand the known SEV proteome and highlight proteins that may influence both male and female reproductive capacity.