Fig. 6

Quantitative proteomics analysis on urine exosomes using label-free method. A Overview of protein identification and the number of identified spectra, peptides, and proteins after data filtering for search library results. B Gene Ontology (GO) annotation of the subcellular locations of the identified proteins. C Scores plot obtained from partial least squares discriminant analysis (PLS-DA) of identified proteins. D Volcano plot of differentially expressed proteins between the normal aging and NCDs groups, where red indicated upregulated proteins and blue indicated downregulated proteins. E Clusters of Orthologous Groups (COG)/eukaryotic orthologous groups (KOG) analysis of metabolic functions of differentially expressed proteins. Comparing the bubble plot of the significantly enriched KEGG pathways of downregulated proteins (F) and upregulated proteins (G) between the normal aging and NCDs groups. Proteins that were differentially expressed were found using fold change ≥ 2 or FC ≤ 0.5. The Benjamini–Hochberg method was applied to manage the false discovery rate (FDR) and the threshold value set to 0.05. Proteins with a corrected P-value < 0.05 were considered significant