Insights into the Effects of Mesenchymal Stem Cell-Derived Secretome in Parkinson's Disease.

Mesenchymal stem cell (MSC)-derived secretome demonstrated therapeutic effects like those reported after MSCs transplantation. MSC-derived secretome may avoid various side effects of MSC-based therapy, comprising undesirable differentiation of engrafted MSCs and potential activation of the allogeneic immune response. MSC-derived secretome comprises soluble factors and encapsulated extravesicles (EVs). MSC-derived EVs comprise microvesicles, apoptotic bodies, and exosomes. In this review, we focus on the recent insights into the effects of MSC-derived secretome in Parkinson's disease (PD). In particular, MSC-derived secretome and exosomal components counteracted neuroinflammation and enhanced antioxidant capacity and neurotrophic factors expression. In light of the insights reported in this review, MSC-derived secretome or their released exosomes may be used as a potential therapeutic approach or as adjuvant therapy to counteract the disease progression and improve PD symptoms. Also, MSC-derived secretome may be used as a vehicle in cell transplantation approaches to enhance the viability and survival of engrafted cells. Furthermore, since exosomes can cross the blood-brain barrier, they may be used as biomarkers of neural dysfunction. Further studies are necessary to fully characterize the bioactive molecules present in the secretome and to create a new, effective, cell-free therapeutic approach towards a robust clinical outcome for PD patients.