Evaluation of dentin sialophosphoprotein (DSPP) in human dental pulp

Methods: dental pulp was obtained from a healthy third molar (age 17) and expression of DSPP was investigated performing a microarray analysis carried out using high density array containing 21.329 transcripts in replicates. Fluorescent signals were captured by ScanArray 5000 Packard laser scanning, analyzed using the “ScanArray Express” and obtained data were statistically analyzed using the S.A.M. system. A real-time RT-PCR analysis was developed to confirm DSPP expression.

Results: using the S.A.M software we performed statistical analysis of microarray results and shortlisted 546 genes with specific pulp expression, in particular DSPP resulted highly expressed. RT-PCR analysis, carried out to confirm the microarray results, showed positive result, confirming the presence of this transcript in the investigated RNA.

Conclusions: the product of DSPP gene is a phosphorylated parent protein that is cleaved post-translationally into three dentin components: dentin sialoprotein, dentin glycoprotein, and dentin phosphoprotein. These proteins are synthesized and secrete to form components of dentin extracellular matrix. The elevated level of DSPP expression in human dental pulp indicated that it may play an essential role for normal tooth development.