Effect of exosomes from adipose-derived stem cells on the apoptosis of Schwann cells in peripheral nerve injury

Aims Recovery after peripheral nerve injury (PNI) is often difficult, and there is no optimal treatment. Schwann cells (SCs) are important for peripheral nerve regeneration, so SC-targeting treatments have gained importance. Adipose-derived stem cells (ADSCs) and their exosomes can promote peripheral nerve repair, but their interactions with SCs are unclear. Methods Purified SCs from sciatic nerve injury sites were harvested, and apoptosis and proliferation of SCs at post-PNI 24 hours were analyzed. The effects of coculture with ADSCs and different concentrations of ADSC-derived exosomes (ADSC-Exo) were studied through in vitro experiments by flow cytometry, CCK8 assay, immunofluorescence staining, and histological analysis. The expression of the apoptosis-related genes Bcl-2 and Bax was also analyzed by qRT-PCR. Results ADSC-Exo reduced the apoptosis of SCs after PNI by upregulating the anti-apoptotic Bcl-2 mRNA expression and downregulating the pro-apoptotic Bax mRNA expression. Further, it also improved the proliferation rate of SCs. This effect was confirmed by the morphological and histological findings in PNI model rats. Conclusion Our results present a novel exosome-mediated mechanism for ADSC-SC cross talk that reduces the apoptosis and promotes the proliferation of SCs and may have therapeutic potential in the future.