Proteomic analysis of the effects of CSF-1 and IL-1 on dental follicle cells

Tooth eruption is a complex physiological process involving both osteogenesis and bone resorption. Signals from the dental follicle (DF) regulate bone remodeling during tooth eruption. Interleukin-1 (IL-1) may be the initial promoter of tooth eruption, whereas colony-stimulating factor-1 (CSF-1) may attract monocytes into the DF and stimulate osteoclast differentiation. In the present study, differential proteomics was employed to explore protein changes in rat DF cells (DFCs) under the effects of CSF-1 and IL-1. A total of 47 protein spots were differentially expressed in rat DFCs, and 40 protein spots were identified by MALDI-TOF-MS. The identified proteins were grouped into functional categories including cytoskeletal proteins, metal-binding proteins, proteins involved in secretion and degradation, cell cycle proteins and stress proteins. In IL-1-induced rat DFCs, 31 proteins were upregulated compared with the control and included heat shock protein -1 (HSP25, also known as HSP27/HSP1), vimentin, TMEM43, the GTP-binding protein Rab-3D, 6-pyruvoyl tetrahydrobiopterin synthase and actin. In total, 7 proteins were downregulated, including serum albumin, GIPC1, DNA primase large subunit, cullin-5 and cyclin-G1. In CSF-1-induced rat DFCs, 3 proteins were upregulated and 7 proteins were downregulated when compared with the controls. The upregulated proteins included the GTP-binding protein Rab-3D and -actin. The downregulated proteins included cullin-5, serum albumin, PDZ domain-containing protein and cyclin-G1. The differential expression of vimentin, actin, HSP25 and Rab-3D was verified by western blotting and reverse transcription-quantitative polymerase chain reaction analyses. The present findings provide an insight into the mechanisms involved in tooth eruption.