Molecular mechanism of fluoride toxicity to ameloblasts based on bioinformatics method / 中华地方病学杂志

ABSTRACT

Objective:To explore the molecular mechanism of fluoride toxicity to ameloblasts.Methods:Mouse ameloblast cell line (LS8 cells) was taken and divided into control group [0.0 mmol/L sodium fluoride (NaF)] and fluoride exposed group (1.6 mmol/L NaF) according to the final concentration of NaF. Transcriptome sequencing was performed to screen differentially expressed genes (DEGs), and gene ontology (GO) analysis and gene set enrichment analysis (GSEA) were performed on DEGs. The STRING database was used to construct the protein-protein interaction (PPI) network of DEGs, and Cytoscape 3.8.0 software was used to visualize the PPI network to screen key modules and key genes. At the same time, real-time fluorescence quantitative PCR was used to detect the mRNA expression level of key genes, and the key genes were verified by gene expression database (GEO database).Results:Compared with the control group, there were 709 DEGs in the fluoride exposed group, including 223 up-regulated genes and 486 down-regulated genes. The GO analysis of DEGs mainly involved molecular functions such as receptor-ligand activity, cell adhesion molecule binding, structural components of extracellular matrix, cellular components such as collagen of extracellular matrix, receptor complex, membrane raft, biological processes such as external packaging structure organization, extracellular structure organization, and extracellular matrix organization. The GSEA of the whole gene set found that the interleukin-17 (IL-17) signaling pathway, ribosome biogenesis in eukaryotes, and the nuclear factor kappa-B (NF-κB) signaling pathway were activated, while fatty acid degradation, pyruvate metabolism and fatty acid metabolism were inhibited. After constructing PPI network, three key modules and four key genes [typeⅠcollagen α1 (Col1a1), typeⅠcollagen α2 (Col1a2), typeⅤcollagen α1 (Col5a1) and fibrinogen 1 (Fbn1)] were obtained. Compared with the control group, the mRNA expression levels of Col1a1, Col1a2, Col5a1 and Fbn1 in LS8 cells of the fluoride exposed group were significantly decreased ( P < 0.05), which was consistent with the change trend of gene expression in the GEO database. Conclusion:Key genes such as Col1a1, Col1a2, Col5a1, Fbn1, and signaling pathways such as IL-17 and NF-κB, which are screened by bioinformatics method, may be closely related to the toxic effects of fluoride on ameloblasts.