Fig 1.
Summary of previously identified phenotypes underlying the radiation damage response in the murine salivary gland over time following exposure to a single 5 Gy dose.
Abbreviations: h = hours, d = days, DNA = deoxyribonucleic acid, ROS = reactive oxygen species.
Fig 2.
Metabolomic profiling of irradiated parotid salivary glands at days 3 (N = 8), 14 (N = 8), and 30 (N = 8) compared to untreated (N = 4) reveals separation.
A) PLS-DA plot of HILIC phase data. B) PLS-DA plot of RP phase data. C) Heatmap of all metabolites identified in HILIC phase. D) Heatmap of all metabolites identified in RP phase. E) Heatmap of differentially altered metabolites in HILIC phase (Padj<0.05). F) Heatmap of differentially altered metabolites in RP phase (Padj<0.05). Abbreviations: IR = radiation, HILIC = hydrophilic interaction liquid chromatography, RP = reverse phase chromatography.
Table 1.
Summary of the top 100 significant metabolites (Padj<0.05) annotated with metabolite class information at days 3, 14, and 30 IR compared to untreated in HILIC and RP phases.
Table 2.
Gene set enrichment analysis (GSEA) of top 3 pathways enriched at days 3, 14, and 30 IR compared to untreated in HILIC and RP phases using (Padj<0.25) for statistical significance.
Fig 3.
MetaMapp network analysis identifies significant metabolite clusters at day 3 IR.
A) HILIC phase. B) RP phase. Rectangles correspond to individual metabolites, edges denote chemical reactions between the metabolites, and numbers denote the communities that clusters of metabolites belong to. Color indicates Log2 (fold difference)—red denotes upregulated metabolite levels versus untreated and blue denotes downregulated metabolite levels versus untreated. Abbreviations: IR = radiation, HILIC = hydrophilic interaction liquid chromatography, RP = reverse phase chromatography.
Table 3.
Significant (Hypergeometric P-value<0.05) MetaMapp metabolite communities at days 3, 14, and 30 IR compared to untreated in HILIC and RP phases.
Table 4.
Significant (Padj<0.25) weighted correlation network analysis (WGCNA) metabolite modules with pathway enrichment annotation at days 3, 14, and 30 IR compared to untreated in HILIC and RP phases.
Fig 4.
Amino acids connected to mitochondrial metabolism.
A) Individual amino acids analyzed by one-way ANOVA with post-hoc Tukey’s test for multiple comparisons. Letters denote statistical significance between groups, P<0.05. Box plots display the upper quartile, median, and lower quartile with the maximum and minimum values denoted by the whiskers. N = 4 for untreated (UT), N = 8 for day 3 (D3) IR, N = 8 for day 14 (D14) IR, and N = 8 for day 30 (D30) IR. Alanine, cysteine and valine were not detected in our data set. B) Overview of pathways related to amino acid metabolism. Created in BioRender.com. Abbreviations: TCA = tricarboxylic acid.