Comparative proteomic analysis of dental cementum from deciduous and permanent teeth

Abstract

It has been suggested that there are histological and functional distinctions between the periodontal tissue of deciduous and permanent teeth. Thus, we hypothesized that extracellular matrix of cementum from deciduous and permanent teeth display differences in the constitutive expression of genes/proteins involved with periodontal tissue homeostasis. Deciduous (n=6) and permanent (n=6) teeth were obtained to generate their dental cementum (DC) proteomes for comparative analysis. DC samples were denatured, followed by protein extraction reduction, alkylation and digestion for analysis by LC/MS-MS. Data analysis showed that a total of 510 proteins were identified for DC harvested from deciduous and permanent teeth, with 123 (24.1%) proteins found exclusively in deciduous DC and 128 (25.1%) proteins exclusively expressed in permanent DC. Sixty (23.2%) proteins were differentially expressed by the beta-binomial statistical test (p<0.05), including myeloperoxidase (MPO), decorin (DCN) and osteocalcin (BGLAP). Next, we propose to conclude the bioinformatics analysis and to validate our proteome findings using immunohistochemistry (IHC) working in collaboration with Dr. Brian L. Foster, Department of Biosciences - The Ohio State University - College of Dentistry, who has extensive experience with IHC assays and has been a long time collaborator. Selected proteins, including MPO, DCN, BGLAP, osteopontin, alkaline phosphatase, bone sialoprotein and periostin identified by proteomic analysis will be confirmed by IHC in decalcified section from deciduous (n=3) and permanent (n=3) teeth. (AU)