Comparative analysis of secretomes from deciduous and permanent periodontal ligament cells

Abstract

The aims of the present study were to identify and compare the secretomes of human deciduous and permanent periodontal ligament (PDL) cells. Secreted proteins were isolated and identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Antibodies against Tudor domain containing 7 (TDRD7) and Vasorin (VASN) were used for western blot. In addition, we used the cytokine membrane array analysis and enzyme-linked immunosorbent assay (ELISA) was performed for some cytokine (VEGF, EGF, PDGF-BB, SCF, and FGF beta). Collagen type VI, alpha I, collagen type I, alpha I, collagen type III, alpha I, cullin 7, and nuclear factor I/X (CCAAT-binding transcription factor) related to cell growth and/or maintenance were identified in deciduous PDL group. But vasorin (VASN), IGF binding protein 4, and S100 calcium binding protein A9 related to cell communication and signal transduction were identified in permanent PDL group. The secretomes that were upregulated in deciduous PDL tissues were involved in inflammatory or immune reactions (IL-1 alpha, IL-1 beta, IL-2, I-309, IL-12 p40/70, IL-4, MMP1). Proteins related to cell growth and/or maintenance, cell communication; signal transduction, inflammatory or immune reactions were slightly different between permanent PDL and deciduous PDL groups. These results show that humoral factors released from deciduous and permanent PDL cells have different characteristics. Although the findings in our study are not sufficient to explain difference between permanent and deciduous PDL clearly, our study provides clues to develop our understanding of the molecular basis.