Table 1.
Representative surface markers of cell subsets for heterogeneous MSCs.
| Cell subset | Surface marker | Comments | References |
|---|---|---|---|
| Fast growing/multipotent MSCs | Low-affinity nerve growth factor receptor (CD271) | Isolation marker that is downregulated in expanded MSCs | [39, 43, 44, 46, 94] |
| Melanoma cell adhesion molecule (CD146) | A pericyte marker expressed in primary and expanded MSCs | [35, 38, 40, 95, 106] | |
| Neuron-glial antigen 2 (NG2) | Upregulated in expanded MSCs. Similar expression in tri- and bipotent MSCs | [35, 47] | |
| Stage-specific embryonic antigen-4 (SSEA-4) | An embryonic stem cell marker expressed on primitive MSCs | [17, 48, 49] | |
| STRO-1 | Clonogenic MSCs constitute a small fraction of the isolated stromal cells | [36, 37, 107] | |
|
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| Osteogenic MSCs | Tissue nonspecific alkaline phosphatase (TNAP) | Selects for MSCs with increased mineralization and expression of osteogenic-related genes | [67] |
|
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| Chondrogenic MSCs | Neural cell adhesion molecule (CD56) | Isolates chrondroprogenitors but is downregulated in expanded MSCs | [70, 71] |
| Receptor tyrosine kinase-like orphan receptor 2 (ROR2) | Isolates chrondroprogenitors from confluent, undifferentiated MSCs | [65] | |
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| Triploblastic MUSE cells | Stage-specific embryonic antigen-3 (SSEA-3) | Selected cells exhibit triploblastic differentiation at the single-cell level | [74–79] |
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| Immunoregulatory MSCs | Tetherin (bone marrow stromal antigen 2, CD317) | MSCs isolated for tetherin expression have proinflammatory properties and may participate in pathogen clearance | [96] |
| Vascular cell adhesion molecule-1 (CD106) | Selects MSCs that suppress inflammatory cytokine and stimulate regulatory T cells | [98–100] | |
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| Aging MSCs | Decoy TRAIL receptor (CD264) | Upregulated concurrently with p21 and remains elevated through senescence | [16] |
MSCs: mesenchymal stem cells. MUSE: multilineage-differentiating stress enduring.