Site-specific N-glycan Analysis of Neonatal Mouse Hearts

The heart of a newborn mouse has an exceptional capacity to regenerate from myocardial injury but lose it after a week of life, which has been utilized as a valuable model to explore the cues for heart regeneration. More and more researches indicated that glycoprotein played an important role in cardiac regeneration. Elucidating the glycosylation processes associated with heart regeneration will be beneficial for the molecular mechanism studies of heart regeneration as well as discovery of potential therapeutic strategies for human cardiac diseases. In this work, an integrated glycoproteomic and proteomic analysis were performed to investigate the differences in glycoprotein abundances and site-specific glycosylation occupancy between neonatal day 1 (P1) and day 7 (P7) of mouse hearts. The intact glycoepeptides were enriched and identified in both P1 and P7 hearts. To screen for differentially regulated glycoproteins, we compared the expression levels of intact glycopeptides between P1 and P7 hearts using label free quantification. Eventually, the glycosylation occupancy of site-specific N-glycans were obtained by comparing the alterations of intact glycopeptides with their corresponding protein expression levels obtained from global proteomic analysis. These altered glycosylation patterns among proteins between P1 and P7 mouse hearts have a significant potential to aid our understanding of the regenerative capacity loss in neonatal mouse hearts during the first week, thus leading to novel therapeutic approaches to recover the capacity.