Concise Review: The Surface Markers and Identity of Human Mesenchymal Stem Cells

Abstract

The concept of mesenchymal stem cells (MSCs) is becoming increasingly obscure due to the recent findings of heterogeneous populations with different levels of stemness within MSCs isolated by traditional plastic adherence. MSCs were originally identified in bone marrow and later detected in many other tissues. Currently, no cloning based on single surface marker is capable of isolating cells that satisfy the minimal criteria of MSCs from various tissue environments. Markers that associate with the stemness of MSCs await to be elucidated. A number of candidate MSC surface markers or markers possibly related to their stemness have been brought forward so far, including Stro-1, SSEA-4, CD271, and CD146, yet there is a large difference in their expression in various sources of MSCs. The exact identity of MSCs in vivo is not yet clear, although reports have suggested they may have a fibroblastic or pericytic origin. In this review, we revisit the reported expression of surface molecules in MSCs from various sources, aiming to assess their potential as MSC markers and define the critical panel for future investigation. We also discuss the relationship of MSCs to fibroblasts and pericytes in an attempt to shed light on their identity in vivo.

Morphological features of IFN-γ–stimulated mesenchymal stromal cells predict overall immunosuppressive capacity

“…Although we tested fewer MSC lines expanded by this second manufacturing process, this result may indicate that morphological characterization must be performed with each manufacturing process to establish useful criteria for identifying MSC preparations with desired immunosuppressive potential. Similarly, MSCs from other tissue sources (adipose, umbilical cord, dental pulp) may possess tissue-specific morphological phenotypes and responses that will need to be characterized to identify potential morphological quality attributes unique to these cell types (42). As this study tested only three MSC lines produced by this second manufacturing process, further study will be required to confirm that unique morphological profiles are correlated with immunosuppressive capacity in bone marrowderived MSC lines produced by varying sources or manufacturing processes.…”

Stem cell therapy for inflammatory bowel disease

“…The latter terms are defined as plastic adherent cells that must express CD105, CD90, and CD73 but lack not only the expression of pan-leukocyte (CD45), endothelial, or primitive hematopoietic (CD34), monocyte (CD14 or CD11b), or B cell (CD79a or CD19) markers, but also the expression of HLA class II (HLA-DR) surface antigen, and show tri-lineage differentiation into osteoblasts, adipocytes, and chondrocytes [7].…”

Chondrocyte Turnover in Lung Cartilage

“…The minimal criteria for defining MSCs include: (a) remain plastic-adherent under standard culture conditions; (b) express CD73, CD90, and CD105, and lack expression of CD34, CD45, CD14 or CD11b, CD79a or CD19, and HLA-DR surface molecules; and (c) differentiate into osteoblasts, adipocytes, and chondrocytes in vitro [83,84].…”

“…Originally isolated from bone marrow, MSCs have being isolated from other sites including spleen, thymus, muscle, adipose tissue, endometrium, placenta, umbilical cord, umbilical cord blood, peripheral blood, periosteum, periodontal ligament, dental pulp, synovium, synovial fluid, tendons, and cartilage [84,85]. A perivascular location for MSCs has been suggested, correlating these cells with pericytes.…”