Exosome Content-Mediated Signaling Pathways in Multiple Sclerosis

Exosomes are small extracellular vesicles with a complex lipid-bilayer surface and 30-150 nm diameter. These vesicles play a critical role in intercellular signaling networks during physiopathological processes through data trafficking and cell reprogramming. It has been demonstrated that exosomes are involved in a variety of central nervous system (CNS) disorders such as multiple sclerosis (MS). Exosome mediators' cell-to-cell communication is possibly by delivering their contents such as proteins, RNAs (coding and non-coding), DNAs (mitochondrial and genomic), and transposable elements to the target cells. Exosomal microRNAs (miRNAs) differ in their expression patterns in MS disease, thereby providing novel diagnostic and prognostic biomarkers and therapeutic options for better treatment of MS disease. Furthermore, these microvesicles are non-immunogenic and non-toxic therapeutic tools for transferring miRNAs across the blood-brain barrier (BBB). Collectively, exosomes could be used as novel drug delivery devices for the treatment of MS patients. This review summarized research regarding the exosomes from serum, plasma, PBMC, and other cells in MS patients and experimental models. We also provide a critical view of exosome content-mediated signaling pathways in MS, including TNF-α, TGF-β, NF-κB, and Wnt pathways. The use of exosomes as a therapeutic potential in MS has also been discussed.