ABSTRACT

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

摘要

组织驻留的干细胞衰老导致干细胞衰竭，这是生理和病理学衰老的主要原因。临床前研究已经报道了干细胞衍生的细胞外囊泡（SC-EVs）具有治疗多种疾病的潜力。然而，SC-EVs是否可以使衰老的组织干细胞恢复活力以预防与年龄有关的疾病仍然是未知的。在这里，我们显示人类胚胎干细胞衍生的小细胞外囊泡（hESC-sEVs）的长期应用可挽救衰老的骨髓间充质干细胞（BM-MSC）的功能，并防止衰老小鼠中与年龄相关的骨质流失。转录组分析显示，hESC-sEVs处理上调了BM-MSC中抗衰老，干细胞增殖和成骨分化相关基因的表达。此外，液相色谱-串联质谱（LC-MS / MS）分析鉴定了hESC-sEV中封装的4122种蛋白质。生物信息学分析预测，hESCs-sEVs中的蛋白质成分以协同方式发挥功能，以诱导多种经典信号通路的激活，包括Wnt，Sirtuin，AMPK，PTEN信号传导，从而导致BM-MSCs中抗衰老基因的上调。然后恢复衰老的BM-MSCs功能。总的来说，我们的发现揭示了hESC-sEVs在逆转BM-MSC衰老和与年龄有关的成骨功能障碍中的作用，从而防止了与年龄有关的骨质流失。由于hESC-sEVs可以减轻组织驻留干细胞的衰老，因此它们可能是与年龄有关的疾病的有希望的治疗候选者。