Benzo[a]pyrene exposure affect the formation of dental hard tissue via the regulation of glycerophospholipid metabolism

Background Enamel is a profound hard tissue of the tooth, and serves functions including protecting dental hard tissues, assisting in mastication, and contributing to facial aesthetics. The formation of enamel involves multiple stages during growth and development, which is highly susceptible to signaling disruptions. Systemic factors such as perinatal complications, preterm birth, and exposure to environmental chemicals can all contribute to the occurrence of developmental defects of enamel (DDE), adversely affecting normal oral physiological functions and impacting patients' daily lives. However, its pathophysiology remains unclear, making precise prevention difficult. Children with DDE who are not diagnosed and treated early face higher oral health risks. Therefore, in-depth research into the mechanisms by which environmental exposures lead to DDE is crucial for identifying preventive and early intervention strategies to promote oral health in early life. Methods Six-week-old SD rats were used to establish the DDE model induced by benzo[a]pyrene (B[a]P) exposure. Phenotypic analysis was conducted through dual-platform untargeted metabolomics sequencing, transcriptomics sequencing, hematological examination, and Micro CT. All data were evaluated statistically using Student’s tests or one-way ANOVA with the Tukey post hoc test ( P  < 0.05). Results B[a]P exposure affects the development and eruption of rat incisors and molars, which disrupting the enamel deposition and leading to the phenotype of DDE. The formation of DDE is accompanied by disordered lipid metabolism in liver and abnormal phospholipid metabolism in dental epithelial cells. Differential metabolites which enriched in the phospholipid metabolism pathway during the progression of DDE are correlated with transcriptional changes in genes related to enamel formation. Conclusions This study established the rat model of DDE and proved the multifaceted impacts of B[a]P exposure on tooth development and body metabolism, revealing the correlation between changes in phospholipid metabolism and transcriptional alterations of genes related to enamel formation. These findings comfirmed the association between environmental exposures and DDE, and suggested the potential preventive targets for DDE, providing further theoretical support for promoting oral health management in early childhood.