The Emerging Role of Mesenchymal Stem Cell Secretome in Cartilage Regeneration

Articular cartilage has a limited capacity to repair following injury. As a result, cartilage injuries often progress to serious joint disorders such as osteoarthritis. Mesenchymal stem cells (MSCs) are currently being evaluated in clinical trials as the therapeutic cell source for treatment of cartilage lesions and osteoarthritis. In addition to their differentiation potential, it is widely accepted that the beneficial actions of MSCs can also be mediated by their secretome. Of note, it has been demonstrated that MSCs are able to secrete a broad range of trophic factors and matrix molecules in their secretome to modulate the injured tissue environment and direct regenerative processes including cell migration, proliferation and differentiation to mediate overall tissue regeneration. The study of MSC secretome not only allows a better mechanistic understanding of the role of MSCs in tissue repair and disease treatment, but also enables the potential development of the next-generation, ready-to-use, highlyamenable and ‘cell-free’ therapeutics for clinical application. In this chapter, we present the latest understanding of MSC secretome and its components as a new paradigm for the treatment of cartilage lesions and osteoarthritis.

Keywords: Cartilage, Exosomes, Extracellular vesicles, Immunomodulation, Mesenchymal stem cells, Osteoarthritis, Secretome, Tissue regeneration.