Seminal plasma N-glycome as a new biomarker of environmental exposure associated with semen quality

Male infertility, a condition that has during the last decade raised significant concern, is a diagnostically demanding and socially sensitive topic. The number of unsolved issues on infertility etiology, especially potential environmental causes, in couples demonstrates the need for further investigations into infertility biomarkers. Semen parameters are often insufficient for reliable profiling of male infertility. Thus, this study aims to evaluate for the first time seminal plasma N-glycosylation as a biomarker of environmental exposure in semen samples from 82 normozoospermic men and 84 men with abnormal semen parameters and compare it with genome damage measured by DNA fragmentation. We obtained information about chronic exposure to environmental factors from the self-reported questionnaire, and determined sperm DNA fragmentation by sperm chromatin dispersion, while N-glycans were characterized with liquid chromatography-mass spectrometry (LC-MS). Based on previously published results, ten N-glycans were selected. Results show that the selected seminal plasma N-glycans were significantly associated with smoking, exposure to pesticides, air pollution, agents emitted during photocopying, alcohol consumption, and obesity. Some N-glycans showed a simultaneous association with DNA fragmentation, semen parameters, and environmental stressors. These subgroups of N-glycans are new potential candidates for biomonitoring of exposure to different environmental factors in men with semen abnormalities.