Exosomal DMBT1 from human urine-derived stem cells facilitates diabetic wound repair by promoting angiogenesis

Abstract

Chronic non-healing wounds represent one of the most common complications of diabetes and need advanced treatment strategies. Exosomes are key mediators of cell paracrine action and can be directly utilized as therapeutic agents for tissue repair and regeneration. Here, we explored the effects of exosomes from human urine-derived stem cells (USC-Exos) on diabetic wound healing and the underlying mechanism.Methods: USCs were characterized by flow cytometry and multipotent differentiation potential analyses. USC-Exos were isolated from the conditioned media of USCs and identified by transmission electron microscopy and flow cytometry. A series of functional assays in vitro were performed to assess the effects of USC-Exos on the activities of wound healing-related cells. Protein profiles in USC-Exos and USCs were examined to screen the candidate molecules that mediate USC-Exos function. The effects of USC-Exos on wound healing in streptozotocin-induced diabetic mice were tested by measuring wound closure rates, histological and immunofluorescence analyses. Meanwhile, the role of the candidate protein in USC-Exos-induced regulation of angiogenic activities of endothelial cells and diabetic wound healing was assessed.Results: USCs were positive for CD29, CD44, CD73 and CD90, but negative for CD34 and CD45. USCs were able to differentiate into osteoblasts, adipocytes and chondrocytes. USC-Exos exhibited a cup- or sphere-shaped morphology with a mean diameter of 51.57 ± 2.93 nm and positive for CD63 and TSG101. USC-Exos could augment the functional properties of wound healing-related cells including the angiogenic activities of endothelial cells. USC-Exos were enriched in the proteins that are involved in regulation of wound healing-related biological processes. Particularly, a pro-angiogenic protein called deleted in malignant brain tumors 1 (DMBT1) was highly expressed in USC-Exos. Further functional assays showed that DMBT1 protein was required for USC-Exos-induced promotion of angiogenic responses of cultured endothelial cells, as well as angiogenesis and wound healing in diabetic mice.Conclusion: Our findings suggest that USC-Exos may represent a promising strategy for diabetic soft tissue wound healing by promoting angiogenesis via transferring DMBT1 protein.

Melatonin alleviates vascular calcification and ageing through exosomal miR‐204/miR‐211 cluster in a paracrine manner

“…By exchange of material such as RNAs, miRNAs, proteins and delivering information, exosomes have been viewed as important mediators of cell‐cell communication . Recipient cells can recycle exosomes back to the extracellular milieu after being taken up by endocytosis . A recent study indicated the paracrine effects of endothelial exosomes .…”

“…46 Recipient cells can recycle exosomes back to the extracellular milieu after being taken up by endocytosis. 47,48 A recent study indicated the paracrine effects of endothelial exosomes. 24 In this study, the exosomes were identified using morphology, size and exosomal markers.…”

Therapeutic Advances of Stem Cell-Derived Extracellular Vesicles in Regenerative Medicine

“…In a mouse model of a skin defect, Fang et al found that hucMSC-EXs contain miR-21, miR-23a, miR-125b, and miR-145, which could synthetically antagonize the TGF-β/Smad2 signaling pathway and inhibit the differentiation and accumulation of myofibroblasts, thus reducing scar formation and promoting wound healing [52]. In another study, Chen et al demonstrated that USC-EXs showed a favorable therapeutic effect on diabetic skin ulcers through that was deleted in malignant brain tumors 1 (DMBT1) [53].…”

Microfluidics‐based on‐a‐chip systems for isolating and analysing extracellular vesicles

“…The endocytic pathway involves the formation of endosomes via a fundamental pathway for the entrance into the cell of large cargoes; the biogenesis of intraluminal vesicles, which are precursors of Exos, in endosomes for the transformation from early endosomes to MVBs, and the fusion between cytomembrane and MVB membrane to release Exos to the outside of the cell. Although initially dismissed as artefacts or “cell debris”, it is now clear that these nano-sized vesicles act as “correspondents” in intercellular communication [18,20,21]. EVs tend to express similar membrane proteins to their parent cells, which could give them potential targeting ability, and, in addition, could make them potential detection targets for use in liquid biopsy.…”