Isolation of Mesenchymal Stem Cells (MSC) from Human Adenoid Tissue

Objectives: Mesenchymal stem cells (MSCs) are multipotent progenitor cells that originally derived from bone marrow. Clinical use of bone marrow‐derived MSC is difficult due to morbidity and low MSC abundance and isolation efficiency. Recently, MSCs have been isolated from various adult tissues. Here we report the isolation of adenoid tissue‐derived MSCs (A‐MSCs) and their characteristics. Methods: We compared the surface markers, morphologies, and differentiation and proliferation capacities of previously established tonsil‐derived MSCs (T‐MSCs) with cells isolated from adenoid tissue. The immunophenotype of A‐MSCs was investigated upon interferon (IFN)‐Î3 stimulation. Results: Both T‐MSCs and A‐MSCs showed negative CD45, CD31 HLA‐DR, and positive CD 90, CD44, and CD73 expression. A‐MSCs were fibroblast‐like, spindle‐shaped non‐adherent cells, similar to T‐MSCs. Adipogenesis was observed in A‐MSCs by the formation of lipid droplets after Oil Red O staining. Osteogenesis was observed by the formation of the matrix mineralization in Alizarin Red staining. Chondrogenesis was observed by the accumulation of sulfated glycosaminoglycan‐rich matrix in collagen type II staining. These data were similar to those of T‐MSCs. Expression of marker genes (ie, adipogenesis; lipoprotein lipase, proliferator‐activator receptor‐gamma, osteogenesis; osteocalcin, alkaline phasphatase, chondrogenesis; aggrecan, collagen type II α1) in A‐MSCs were not different from those in T‐MSCs. Conclusions: A‐MSCs possess the characteristics of MSCs in terms of morphology, multipotent differentiation capacity, cell surface markers, and immunogeneity. Therefore, A‐MSCs fulfill the definition of MSCs and represent an alternate source of MSCs.