Characterization of protein lactylation in relation to cardiac metabolic reprogramming in neonatal mouse hearts

Abstract Background In mammals, the neonatal heart regenerates within a short time after birth, but adults lack this ability. The metabolic patterns of embryonic and adult hearts are completely different. We have shown that metabolic reprogramming is critical for cardiomyocyte proliferation in the neonatal heart. However, the molecular mechanism of metabolic reprogramming in neonatal heart still needs to be explored. Herein, we revealed that cardiac metabolic reprogramming could be regulated by altering global protein lactylation. Results 4D label-free proteomics and Kla omics were performed in postnatal Day 1 (P1), 5 (P5), and 7 (P7) mouse hearts, 2297 Kla sites from 980 proteins were identified, and 1262 Kla sites from 409 proteins were quantified. Functional clustering analysis of proteins with altered Kla sites revealed that the proteins were mainly involved in metabolic processes. The Kla levels in several fatty acid oxidation-related proteins showed high expression at P5, while most glycolysis and cell cycle-related proteins were sustainedly decreased from P1-P7. Furthermore, we verified the Kla levels of several differentially modified proteins, including ACAT1, ACADL, ACADVL, PFKM, PKM and NPM1, by coimmunoprecipitation and Western blotting. Conclusions We reported the first comprehensive Kla map in the neonatal mouse heart, which will aid in understanding the regulatory network of metabolic reprogramming and cardiac regeneration.