Multifunctional role of microRNAs in mesenchymal stem cell-derived exosomes in treatment of diseases

Mesenchymal stem cells can be replaced by exosomes for the treatment of inflammatory diseases, injury repair, degenerative diseases, and tumors. Exosomes are small vesicles rich in a variety of nucleic acids [including messenger RNA, Long non-coding RNA, microRNA (miRNA), and circular RNA], proteins, and lipids. Exosomes can be secreted by most cells in the human body and are known to play a key role in the communication of information and material transport between cells. Like exosomes, miRNAs were neglected before their role in various activities of organisms was discovered. Several studies have confirmed that miRNAs play a vital role within exosomes. This review focuses on the specific role of miRNAs in MSC-derived exosomes (MSC-exosomes) and the methods commonly used by researchers to study miRNAs in exosomes. Taken together, miRNAs from MSC-exosomes display immense potential and practical value, both in basic medicine and future clinical applications, in treating several diseases.