Early osteogenic differential protein profile detected by proteomic analysis in human periodontal ligament cells

Human periodontal ligament cells play a pivotal role in maintaining periodontal ligament space, contain progenitors that are able to differentiate into cementoblasts/osteoblasts and have a tremendous potential to regenerate periodontal tissue. However, the exact molecular mechanisms governing the differentiation mechanisms of progenitors in periodontal ligament cells remain largely unknown. This study was carried out to investigate the differentially expressed proteins involved in the osteogenic differentiation of progenitors presented in periodontal ligament cells.

Using two-dimensional gel electrophoresis, mass spectrometry and peptide mass fingerprinting, we analyzed the differential protein profiles of periodontal ligament cells undergoing mineralization.

Compared with undifferentiated periodontal ligament cells, 61 proteins in periodontal ligament cells undergoing differentiation showed at least a 1.5-fold change in intensity, of which 29 differentially expressed proteins were successfully identified by matrix-assisted laser-desorption ionization time-of-flight mass spectrometry. The expression of some of the identified proteins was further confirmed by western blotting and reverse transcription-polymerase chain reaction analysis. The identified proteins were cytoskeleton proteins and cytoskeleton-associated proteins, nuclear proteins and cell membrane-bound molecules.

Our results suggest that the proteins identified in this study may be associated with the unique function of periodontal ligament cells in maintaining periodontal tissue homeostasis, thus providing a comprehensive reference for understanding and investigating in greater detail the molecular mechanisms of periodontal ligament cells involved in periodontal regeneration.