Fig. 1

Nucleotide metabolism centered around adenosine is significantly elevated in SSc. (A) Clinical characteristics of SSc patients (n = 35). (B-D) Orthogonal projections to latent structures-discriminant analysis (OPLS-DA) showing group distribution (B), volcano plot representing differentially expressed metabolites (C) and Z-score plot showing significantly upregulated and downregulated metabolites (D) of plasma samples from SSc patients (n = 35) and HC (n = 14) groups. (E) Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis based on significantly upregulated metabolites of SSc patients. (F) Differential metabolites in the nucleotide metabolism pathway of SSc patients compared to HC. (G) Schematic representation of ATP to adenosine hydrolysis pathway. Arrowheads indicate significantly upregulated metabolites in SSc patients. (H) Plasma adenosine concentrations in SSc patients (n = 20) and HC (n = 15). Error bar represents mean +/- SD range. *P < 0.05; HC, healthy control