Proteomic analysis of dental pulp from deciduous teeth in comparison to permanent teeth: an in-vitro study.

PURPOSE

The aims of this study were to identify proteomic profiles of dental pulp from deciduous teeth and compare the profiles of the two dentitions.

METHODS

Teeth that were caries-free and had normal pulp conditions were collected from twelve healthy individuals. The obtained teeth consisted of deciduous teeth (n = 6) and permanent teeth (n = 6). Proteins were extracted from pulp tissue and then analysed using liquid chromatography-tandem mass spectrometry. MaxQuant was used to identify and quantify proteins from raw mass spectrometry data of the collected deciduous and previously analysed permanent dental pulp. Differentially expressed proteins (DEPs) between the dental pulp of the two dentitions were identified by a statistical analysis conducted using Metaboanalyst with criteria P-value < 0.05 and fold change > 2.

RESULTS

A total of 3,636 proteins were identified in the dental pulp of deciduous teeth. The biological process functional classifications of these proteins were primarily concerned with cellular process, biological regulation, metabolic process and response to stimulus. Dental pulp protein profiles differed significantly between deciduous and permanent teeth, with 736 proteins being differentially expressed, the majority of which were highly expressed in the pulp of deciduous teeth. Pathway analysis indicated DEPs to be involved in tumour necrosis factor (TNF) signalling, nuclear factor kappa B signalling, and odontoclast/osteoclast differentiation.

CONCLUSION

While the dental pulp of deciduous and permanent teeth shares some characteristics, there are also significant differences in protein expression, with the TNF signalling pathway and odontoclast/osteoclast differentiation being promoted in the dental pulp of deciduous teeth.