Role of Glycolysis/Gluconeogenesis and HIF-1 Signaling Pathways in Rats with Dental Fluorosis Integrated Proteomics and Metabolomics Analysis

Abstract

Fluoride is widely distributed, and excessive intake will lead to dental fluorosis. In this study, six offspring rats administrated 100 mg/L sodium fluoride were defined as the dental fluorosis group, and eight offspring rats who received pure water were defined as the control group. Differentially expressed proteins and metabolites extracted from peripheral blood were identified using the liquid chromatography tandem mass spectrometry and gas chromatography mass spectrometry, with the judgment criteria of fold change >1.2 or <0.83 and p < 0.05. A coexpression enrichment analysis using OmicsBean was conducted on the identified proteins and metabolites, and a false discovery rate (FDR) < 0.05 was considered significant. Human Protein Atlas was used to determine the subcellular distribution of hub proteins. The Gene Cards was used to verify results. A total of 123 up-regulated and 46 down-regulated proteins, and 12 up-regulated and 2 down-regulated metabolites were identified. The significant coexpression pathways were the HIF-1 (FDR = 1.86 × 10−3) and glycolysis/gluconeogenesis (FDR = 1.14 × 10−10). The results of validation analysis showed the proteins related to fluorine were mainly enriched in the cytoplasm and extrinsic component of the cytoplasmic side of the plasma membrane. The HIF-1 pathway (FDR = 1.01 × 10−7) was also identified. Therefore, the HIF-1 and glycolysis/gluconeogenesis pathways were significantly correlated with dental fluorosis.

Keywords: HIF-1 pathway; dental fluorosis; fluoride; glycolysis/gluconeogenesis pathway.

Figure 1

Establishment of animal model for dental fluorosis, (a) shows normal dental of mice (n = 8) and (b) shows dental fluorosis of mice (n = 6). The differentially expressed proteins and metabolites extracted from peripheral blood using the liquid chromatography tandem mass spectrometry and gas chromatography mass spectrometry, the fold change >1.2 or <0.83 and p < 0.05 were considered significant. A total of 169 differentially expressed proteins and 14 differentially expressed metabolites were obtained. The volcano of proteomics (c) and metabolomics (d) in the dental fluorosis group and control group.

Figure 2

The top 15 coexpression KEGG pathways integrated proteomics and metabolomics using the OmicsBean, FDR < 0.05 (a). Proteins and metabolites interaction network diagram obtained from the OmicsBean platform show the differentially expressed proteins and metabolites related to the HIF-1 signaling pathway and glycolysis/gluconeogenesis pathway in the dental fluorosis group and control group (b). The samples included 6 dental fluorosis rats and 8 normal dental rats.

Figure 3

Gene ontology (biological process, cellular component, and molecular function) enrichment analysis was conducted between proteomics and metabolomics. The samples included 6 dental fluorosis rats and 8 normal dental rats.

Figure 4

The top 10 gene ontology (a) and top 15 KEGG pathways (b) enrichment analysis of fluoride-related genes using oebiotech, and the fluoride-related genes are obtained from Gene Cards (https://www.genecards.org/; accessed on 18 April 2022) with a score greater than 1.5.