MSC-Derived Exosomes-Based Therapy for Peripheral Nerve Injury: A Novel Therapeutic Strategy

Abstract

Although significant advances have been made in synthetic nerve conduits and surgical techniques, complete regeneration following peripheral nerve injury (PNI) remains far from optimized. The repair of PNI is a highly heterogeneous process involving changes in Schwann cell phenotypes, the activation of macrophages, and the reconstruction of the vascular network. At present, the efficacy of MSC-based therapeutic strategies for PNI can be attributed to paracrine secretion. Exosomes, as a product of paracrine secretion, are considered to be an important regulatory mediator. Furthermore, accumulating evidence has demonstrated that exosomes from mesenchymal stem cells (MSCs) can shuttle bioactive components (proteins, lipids, mRNA, miRNA, lncRNA, circRNA, and DNA) that participate in almost all of the abovementioned processes. Thus, MSC exosomes may represent a novel therapeutic tool for PNI. In this review, we discuss the current understanding of MSC exosomes related to peripheral nerve repair and provide insights for developing a cell-free MSC therapeutic strategy for PNI.

Figure 1

Biogenesis and uptake of exosomes. Endosomes are formed by an invagination in the plasma membrane of cells. As endosomes mature, the endosomal membrane constantly buds inward to form multivesicular bodies (MVBs). Exosomes are released through the fusion of multivesicular bodies with the plasma membrane. Once an exosome is released, receptor cells uptake the exosome through endocytosis, membrane fusion, or receptor-mediated internalization.