Seminal Plasma Protein N-Glycan Peaks Are Potential Predictors of Semen Pathology and Sperm Chromatin Maturity in Men

Tihana Maric,Ana Katusic Bojanac,Tea Petrovic,Evangelini Evgeni,Aleksandra Fucic,Gordan Lauc,Irena Trbojevic-Akmacic,Marco Bruzzone,Ana Matijevic,Iwona Wójcik,Marcello Ceppi,Davor Jezek

doi:10.3390/life11090989

Abstract

Background: Male infertility is increasingly becoming a health and demographic problem. While it may originate from congenital or acquired diseases, it can also result from environmental exposure. Hence, the complexity of involved molecular mechanisms often requires a multiparametric approach. This study aimed to associate semen parameters with sperm DNA fragmentation, chromatin maturity and seminal plasma protein N-glycosylation. Methods: The study was conducted with 166 participants, 20–55 y old, 82 normozoospermic and 84 with pathological diagnosis. Sperm was analyzed by Halosperm assay and aniline blue staining, while seminal plasma total protein N-glycans were analyzed by ultra-high-performance liquid chromatography. Results: Sperm DNA fragmentation was significantly increased in the pathological group and was inversely correlated with sperm motility and viability. Seminal plasma total protein N-glycans were chromatographically separated in 37 individual peaks. The pattern of seminal plasma N-glycan peaks (SPGP) showed that SPGP14 significantly differs between men with normal and pathological semen parameters (p < 0.001). The multivariate analysis showed that when sperm chromatin maturity increases by 10%, SPGP17 decreases by 14% while SPGP25 increases by 25%. Conclusion: DNA integrity and seminal plasma N-glycans are associated with pathological sperm parameters. Specific N-glycans are also associated with sperm chromatin maturity and have a potential in future fertility research and clinical diagnostics.

Highlights

Male infertility, defined as the inability of a fertile female partner to achieve pregnancy, affects approximately 7% of men worldwide and has risen globally in the past few decades [1,2]
We confirmed previous studies that indicate the importance of sperm DNA fragmentation testing and the strong inverse correlation of DNA fragmentation index (DFI) and sperm motility and viability
We detected the novel total protein seminal plasma N-glycan peak SPGP14, whose reduction showed a significant tendency towards pathological semen parameters

Summary

Introduction

Male infertility, defined as the inability of a fertile female partner to achieve pregnancy, affects approximately 7% of men worldwide and has risen globally in the past few decades [1,2]. Its inadequacy in explaining and understanding subtle mechanistic changes in cellular or seminal characteristics that differentiate fertile from infertile subjects requires further development of diagnostic approaches [7,8]. This is especially important for assisted reproductive technology (ART) where prognostic markers of the successful outcome are not always correlated with the ones that define male fertility potential and require additional seminal analysis with more complex prediction models [9]. This study aimed to associate semen parameters with sperm DNA fragmentation, chromatin maturity and seminal plasma protein N-glycosylation. Specific N-glycans are associated with sperm chromatin maturity and have a potential in future fertility research and clinical diagnostics

Objectives

Methods

Discussion

Conclusion