Changes Of N-glycosylation In Human Serum And IgG After Acute Exercise Fatigue

Objective: Exercise fatigue is a common non-specific symptom and has always been a research hotspot in the field of exercise science.However,there are not many studies on the judgment of the degree of exercise fatigue,and most of the biomarkers used to assess exercise fatigue are related to protein at this stage.Glycosylation is the most common protein posttranslational modification process in organisms and plays a key role in physiological processes such as protein folding and cell communication.Finding changes in N-glycan structure and content after exercise fatigue is crucial for understanding the occurrence of fatigue and discovering relevant biomarkers.Therefore,this study aimed to explore the screening of Nglycan markers associated with exercise fatigue from serum and purified IgG for the assessment and monitoring of exercise fatigue.Methods: A total of 15 college students majoring in physical education were recruited in this study to establish a human acute exercise fatigue model by power cycling,and blood samples were collected before and after exercise.The serum and purified IgG N-glycans before and after exercise fatigue were analyzed by MALDI-TOF-MS,and the changes of serum and IgG N-glycans before and after exercise fatigue were explored from the aspects of single Nglycan and specific glycan characteristics.Results: By mass spectrometry,46 and 26 N-glycans were detected in serum and IgG,respectively.The statistical results showed that there were significant differences between 4serum N-glycans and 2 IgG N-glycans before and after exercise fatigue.In serum,H4N4 was significantly up-regulated after exercise fatigue,and H4N5F1,H5N4S1F1 and H6N5S2F1 were significantly down-regulated after exercise fatigue.Among IgG,H5N5F1 was significantly upregulated after exercise fatigue,and H5N5S1F1 was significantly down-regulated after exercise fatigue.Next,the present study assessed changes in glycosylation profiles of 10 serum and 9IgG N-glycans after exercise fatigue.Statistical results showed that serum changes after exercise fatigue showed a decrease in core fucosylated N-glycans,while IgG showed an increase in digalactosylated N-glycans.Conclusion: The 6 N-glycans discovered can be used as potential markers.Acute exercise fatigue induces changes in serum and IgG N-glycosylation,and serum core fucosylation levels are significantly downregulated after acute exercise fatigue,which is consistent with the glycosyltransferase(FUT8)responsible for core fucosylation.associated with low expression.The level of IgG digalactosylation was significantly up-regulated after acute exercise fatigue,suggesting that anti-inflammatory effects are induced after acute high-intensity exercise and may also be associated with exercise-induced increases in blood pressure.Therefore,revealing the changes of serum and IgG N-glycans before and after exercise fatigue will help to clarify the mechanism of exercise fatigue and provide new perspectives and biomarkers for the study of exercise fatigue.