The Role of Exosomal Vimentin in Mediating Wound Healing

Despite great advances in tissue engineering and regenerative medicine,impaired wound healing is still a challenging clinical problem. Accumulating evidence demonstrates the ability of extracellular vesicles and specifically, exosomes in regenerative therapy and tissue engineering. Previous studies showed that adipose stem cell-derived exosomes have great potential in accelerating cutaneous wound healing by affecting fibroblast activities. It has been shown that vimentin serves as a coordinator of the healing process. Interestingly, vimentin has been reported to be detectable in exosomes from different cell types which we called exosomal vimentin. Therefore, we hypothesized that vimentin incorporated into the exosomes may contribute to mediating fibroblast activities in wound healing.
During my Ph.D. thesis, we revealed the active and necessary role of exosomal vimentin in promoting wound healing. Our results revealed that exosomal vimentin from adipocyte progenitor cells acts as a promoter of fibroblast proliferation, migration, and ECM secretion. Our results suggested that exosomes can serve as an efficient transportation system to deliver and internalize vimentin into target cells, while vimentin could have an impact on exosome transportation, internalization, and cell communication. Furthermore, our findings revealed that during mechanical stress such as osmotic imbalance, exosomal vimentin can protect fibroblasts against stress and inhibit stress induced apoptosis. These data suggest that exosomes could be considered either as a stress modifier to restore the osmotic balance or as a conveyer of stress to induce osmotic stress-driven conditions. In conclusion, our in vitro and in vivo experiments provide evidence that exosomal vimentin shortens the healing time and reduces scar formation.