Atlas of lysine propionylation in the human right atrium reveals ALDH6A1-NADH pathway involved in the new-onset atrial fibrillation in aging after coronary artery bypass grafting

Lysine propionylation modification (Kpr) plays an important role in the pathogenesis of several cardiovascular diseases, but the role of Kpr in postoperative atrial fibrillation (POAF) is unclear. Here, we established an atlas of proteomics and propionylation proteomics in the atrial appendage tissues from 28 aging CABG patients, exploring the role of Kpr proteins in the occurrence of POAF. The Kpr of ALDH6A1 was most significantly increased on Lys113 (2.25 folds). The activity of ALDH6A1 increased due to higher binding energy of propionylated ALDH6A1 and NAD+, causing an increase in NADH levels in cells and triggering abnormal energy metabolism. Furthermore, the increase in NADH levels triggered the accumulation of reactive oxygen species, which may cause oxidative stress and cardiac electrical remodeling, resulting in the development of AF. This study reveals the important role of ALDH6A1-NADH pathway in POAF, and provides new insights for exploring the pathogenesis of POAF in CABG.