Human Mesenchymal Stem Cells Promote Ischemic Repairment and Angiogenesis of Diabetic Foot Through Exosome miRNA-21-5p

Abstract

Background: Diabetic foot is caused by ischemic disease of lower extremities of diabetic patients, and the effective therapy is very limited. Mesenchymal stem cells (MSCs) based cell therapy had been developed into a new treatment strategy for diabetic foot clinically. However, the underlying molecular mechanism remains to be fully addressed. Exosomes secreted by MSCs may play crucial role in the processes of MSCs mediated inhibition of inflammatory microenvironment as well as pro-angiogenesis of ischemic tissue of diabetic foot. Methods: Exosomes were isolated from MSCs using ultra-high centrifugation, and further characterized by the nanoparticle tracking analyzer and flow cytometry. Moreover, RNA sequencing, Western Blot, in vitro cell proliferation, in vivo pro-angiogenesis, as well as ischemic repairment of diabetic foot through rat model were performed to evaluate exosome physiological functions. Results: We found that different inflammatory cytokines (tumor necrosis factor a, vascular cell adhesion molecule-1 and interleukin-6) induced MSCs to secrete exosomes heterogeneously, including exosome size and quantity. Through RNA sequencing, we defined a new proangiogenic miRNA, miRNA-21-5p. Further knockdown and overexpression of miRNA-21-5p by manipulating MSCs validated the biological activity of exosome miRNA-21-5p, including in vitro cell proliferation, in vivo pro-angiogenesis in Chick Chorioallantoic Membrane (CAM) assay, and in vivo pro-angiogenesis experiments (tissue injury and repair) in diabetic rat models. Furthermore, we discovered that exosomemiRNA-21-5p promoted angiogenesis through upregulations of vascular endothelial growth factor receptor (VEGFR) as well as activations of serine/threonine kinase (AKT) and mitogen-activated protein kinase (MAPK). Together, our work suggested miRNA-21-5p could be a novel mechanism by which exosomes promote ischemic tissue repairing and angiogenesis. Meanwhile, miRNA-21-5p could be potentially developed into a new biomarker for exosomes of MSCs to treat diabetic foot. Conclusions: miRNA-21-5p is a new biomarker and a novel mechanism by which exosomes promote ischemic tissue repairing and angiogenesis of diabetic foot. Our work could not only provide new scientific evidences for revealing pro-angiogenesis mechanism of MSCs, but also eventually benefit MSCs-based clinical therapy for diabetic foot of diabetes patients.

Exosome‐transmitted miR‐769‐5p confers cisplatin resistance and progression in gastric cancer by targeting CASP9 and promoting the ubiquitination degradation of p53

“…Exosomal miRNA can be transported to recipient cells and change their phenotype through changes in gene expression. [42][43][44] For example, drugresistant cancer cells may release exosomal miRNAs into the microenvironment, causing the recipient cells to develop drug resistance. [45][46][47] This ability of exosomes shed from tumour-resistant cells to transfer drug-resistant phenotypes to drug-sensitive cells is considered an important mechanism of drug resistance that is mainly spread through drug efflux pumps and miRNAs' transfer.…”

Nonalcoholic Fatty Liver Hepatocyte-Derived lncRNA MALAT1 Aggravates Pancreatic Cell Inflammation via the Inhibition of Autophagy by Upregulating YAP

“…Exosomal Hic-5 regulates osteosarcoma phenotype [25]. Human mesenchymal stem cells promote ischemic repairment and angiogenesis of diabetic foot through exosomal miRNA-21-5p [26]. In NAFLD, stressed/damaged hepatocytes release large amounts of EVs, leading to the development of in ammation, brogenesis, and angiogenesis, which are key pathobiological processes in the progression of liver disease [27].…”

Exosome-transmitted miR-769-5p confers cisplatin resistance and tumorigenesis in gastric cancer by targeting CASP9 and promoting the ubiquitination degradation of p53

“…miRNAs can be encapsulated in exosomes to avoid degradation. Exosomal miRNA can be transported to recipient cells and change their phenotype through changes in gene expression [32][33][34]. For example, drug-resistant cancer cells may release exosomal miRNAs into the microenvironment, causing the recipient cells to develop drug resistance [35][36][37].…”