Comprehensive Analysis of Lysine β-Hydroxybutyrylation Modification in Ischemia–Reperfusion Injury in Mouse Heart Transplantation

Background. Ischemia–reperfusion (I/R) is an inevitable adverse outcome after heart transplantation, ultimately leading to graft dysfunction and affecting patient survival. Lysine β-hydroxybutyrylation (Kbhb) is a newly identified form of posttranslational modification that has been shown to be correlated with several cardiovascular diseases. This research sought to analyze the changes in Kbhb protein expression in myocardial tissues of mice with cold ischemia and reperfusion of the heart and to investigate its potential mechanisms. Methods. The myocardial cold ischemia–reperfusion model was constructed using heterotopic abdominal heart transplantation in syngeneic C57/BL6J mice, and the myocardial tissue samples from 6 mice were examined using a combination of liquid chromatography-tandem mass spectrometry. Results. After I/R, 43 upregulated and 18 downregulated proteins were identified. Among these, there were 50 upregulated and 18 downregulated Kbhb sites, including Ttn_K16192, Septin9_K355, and Auh_K186. Kyoto Encyclopedia of Genes and Genomes and protein–protein interaction network analyses indicated significant enrichment of differentially modified proteins in myocardial contraction and energy metabolism. Conclusions. The differential expression of Kbhb-modified proteins revealed their potential roles in cold I/R injury after cardiac transplantation, laying the foundation for further exploration of the biological functions and clinical relevance.