Proteomic analysis of small extracellular vesicles derived from human ESCs

Tissue-resident stem cell senescence leads to stem cell exhaustion, which is a major cause of physiological and pathological aging. Stem cells-derived extracellular vesicles(SCs-EVs) have been reported to possess therapeutic potential in preclinical studies for diverse diseases. However, whether SCs-EVs could rejuvenate senescent tissue stem cell to prevent age-related disorders still remains unknown. Here, we showed that chronic application of human embryonic stem cells-derived extracellular vesicles (hESCs-sEVs) rescues senescent bone marrow MSCs (BM-MSCs) function and prevents age-related bone loss in aging mice. Transcriptome analysis revealed that hESCs-sEVs treatment up-regulates the expression of genes involved in anti-aging, stem cell proliferation and osteogenic differentiation in BM-MSCs. Furthermore, liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis identified 4122 proteins encapsulated in hESCs-sEVs. Bioinformatics analysis predicated that protein components in the hESCs-sEVs function in a synergistic way to induce the activation of several canonical signaling pathways, including Wnt, Sirtuin, AMPK, PTEN signaling, which results in the up-regulation of anti-aging genes in BM-MSCs and then the recovery of senescent BM-MSCs function. Collectively, our findings reveal the effect of hESCs-sEVs in reversing BM-MSCs senescence and age-related osteogenic dysfunction, and thereby preventing age-related bone loss. Given that hESCs-sEVs could alleviate senescence of tissue-resident stem cells, it might be a promising therapeutic candidate for age-related diseases.