Fig. 2: PEA-identified proteins and biological functions involved in AMS.

a Volcano plot of PEA-identified DEPs between the AMS4k (n = 10) and AMS1k (n = 10) groups. Proteins with no statistical significance (q value ≥ 0.05, gray dots) and DEPs (q value < 0.05, red dots) with absolute value of log₂FC larger than 0.5 are labeled with gene symbols. b PCA plot based on PEA-identified DEPs. The AMS1k (light red dots) and AMS4k (sky-blue dots) samples were well separated by PCA using the PEA-identified DEPs without missing values (n = 42). c Abundance heatmap and KEGG pathway enrichment diagram of the PEA-identified DEPs. The scaled abundance heatmap of DEPs between the AMS4k and AMS1k groups per sample is shown on the left side. The hierarchical cluster analysis in the heatmap showed that the 47 DEPs could clearly distinguish the AMS4k group (red hierarchical tree) and AMS1k group (blue hierarchical tree), and the DEPs could be separated into cluster 1 (purple hierarchical tree) and cluster 2 (brown hierarchical tree). Dot plots of the KEGG enrichment of the two clusters with p values < 0.05 are presented on the right side. Cytokine–cytokine receptor interactions and the TNF signaling pathway were enriched in cluster 1 (purple fonts), and nitrogen metabolism and the pentose phosphate pathway were mainly enriched in cluster 2 (brown fonts).