Research Paper Volume 15, Issue 5 pp 1237—1256

Figure 3. Senescent MSCs secrete unique EXO miRNA profile. MiRNA content from pre- and senescent MSC secreted EXOs were characterized and examined using immunoblots and microarrays. Pre-senescent and senescent harvested EXOs showed positive expression of EXO surface markers (EEA1, CAV-1, clathrin, β-actin) using immunoblots (A). Many miRNAs that were significantly regulated were positively enriched in senescent MSC EXOs compared to pre-senescent MSC EXOs (senescent vs. pre-senescent) (B). Microarray analysis showed overlapping miRNAs were involved in similar transcriptome pathways. Significant miRNAs that were involved in TGF-β (C), cell cycle regulation (D), and cell adhesion and focal adhesion (E) pathways are listed. DIANA miRPath analysis further showed miRNAs that regulated genes reported in transcriptome analysis (F). Venn diagrams indicate that several miRNAs regulate and target multiple genes in different pathways. miRNA microarray samples were processed (n = 3) and miRNAs were considered significant if p < 0.05 and fold changes are reported as log2 differences.