Lactylation of nucleus pulposus cells

Nucleus pulposus (NP) resides in hypoxic microenvironment due to the avascular structure of intervertebral disc (IVD). Intracellular lactate drives lysine lactylation (Kla) as a newly epigenetic modification. However, the impact of Kla on NPCs remains unknown. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), we showed a global lactylome profiling on NPCs cultured in normoxia and hypoxia environment and found that 3510 lactylation sites on 1052 proteins in NPCs on non-histone proteins. Moreover, there are 18 proteins with 129 Kla sites exclusively detected in the normoxia group, and 117 Kla sites in 27 proteins were specific in hypoxia group. Together, our dates reveals that Kla plays an important role in regulating cellular metabolism and may contribute to IDD progression.