Mesenchymal Stem Cells in Neurodegenerative Diseases
Katsuda, T., et al. (2015). “Potential application of extracellular vesicles of human adipose tissue-derived mesenchymal stem cells in Alzheimer’s disease therapeutics.” Methods Mol Biol 1212: 171-181. In the last 20 years, extracellular vesicles (EVs) have attracted attention as versatile cell-cell communication mediators. The biological significance of EVs remains to be fully elucidated, but many reports have suggested that the functions of EVs mirror, at least in part, those of the cells from which they originate. Mesenchymal stem cells (MSCs) are a type of adult stem cell that can be isolated from connective tissue including bone marrow and adipose tissue and have emerged as an attractive candidate for cell therapy applications. Accordingly, an increasing number of reports have shown that EVs derived from MSCs have therapeutic potential in multiple diseases. We recently reported a novel therapeutic potential of EVs secreted from human adipose tissue-derived MSCs (hADSCs) (also known as adipose tissue-derived stem cells; ASCs) against Alzheimer’s disease (AD). We found that hADSCs secrete exosomes carrying enzymatically active neprilysin, the most important beta-amyloid peptide (Abeta)-degrading enzyme in the brain. In this chapter, we describe a method by which to evaluate the therapeutic potential of hADSC-derived EVs against AD from the point of view of their Abeta-degrading capacity.
Exosomes are extracellular vesicles with diameters of 30-100nm that are key for intercellular communication. Almost all types of cells, including dendritic cells, T cells, mast cells, epithelial cells, neuronal cells, adipocytes, mesenchymal stem cells, and platelets, can release exosomes. Exosomes are present in human body fluids, such as urine, amniotic fluid, malignant ascites, synovial fluid, breast milk, cerebrospinal fluid, semen, saliva, and blood. Exosomes have biological functions in immune response, antigen presentation, intercellular communication, and RNA and protein transfer. This review provides a brief overview of the origin, morphological characteristics, enrichment and identification methods, biological functions, and applications in tissue engineering and neurological diseases of exosomes.