Proteomic Investigation of Human Dental Pulp to Identify Individuals Who Are Pregnant

Biomolecules preserved in dental pulp are increasingly being used to identify individuals in the context of forensics and archaeology. Despite the vast amount of research into host and pathogen DNA, the potential use of physiologically informative proteins preserved in dental pulp has rarely been studied. Here, we hypothesized that pregnancy-specific proteins circulating in the blood could be identified from the dental pulp of postpartum individuals and this was investigated using eight human third molars extracted from four postpartum and three control individuals during clinical treatment. A total of 885 proteins were identified from these eight dental pulp samples using liquid chromatography coupled tandem mass spectrometry, whose gene ontology compositions were similar to previous studies. However, despite our hypothesis, pregnancy-specific proteins were not identified from the dental pulp of postpartum individuals (n = 5, 4-12 months postpartum). Although the dental pulp proteomes obtained from three individuals postpartum ≤6 months were distinct from those of other individuals by principal component analysis (PCA), their driving proteins were less evident. Although our hypothesis was not supported, sample collection, protein extraction, and mass spectrometry analysis could be improved to explore the forensic application of detecting pregnancy-specific proteins in dental pulp.