Fig. 2

Sulfur-associated DEGs distinguish classes C1 and C2, along with their differentially enriched functions. A The Venn diagram shows ten overlapping genes between DEGs and sulfur-associated gene sets (i.e., cysteine metabolic process, regulation of sulfur metabolic process, and disulfidptosis gene sets). DEGs: differentially expressed genes between OA and healthy groups. B The violin plot shows the expression of the ten 10 sulfur metabolism-associated DEGs. C The bar graph shows the consistency within each group following consensus cluster analysis. Different colors represent the K-value or the number of groups set in each round of the clustering algorithm. The clustering solution based on K = 2 groups shows a higher intra-group consistency compared to other K values. D The heatmap shows two classes distinguished by consensus cluster analysis based on the 10 sulfur-associated DEGs. E, F Clusters identified by tSNE analysis for the expression profile of all genes. These are labeled with colors for healthy/OA groups (E) or C1/C2 groups (F), and the results suggest a consistency between the two classifications G, H. KEGG (G) and GO (H) enriched functions for the upregulated genes in class C2 (OA-dominated); e.g., cell adhesion molecules, IL-17 signaling pathways, rheumatoid arthritis, extracellular matrix, and leukocyte migration. I, J KEGG (I) and GO (J) enriched functions for genes upregulated in class C1 (healthy-dominated); e.g., tyrosine metabolism, fatty acid degradation, and lipid transport.`