Table 1 Summary of the most commonly used biomarkers to identify MSCs from perinatal tissues

1

CD73

(NT5E)

Ecto-5’-nucleotidase

Anchored to the external surface of the cell membrane

Ectoenzyme

(Degrades extracellular AMP into adenosine)^*

Recognized by the ISCT committee

[1, 2, 11,12,13,14]

2

CD90

(Thy-1)

Thymocyte differentiation antigen 1

Anchored to the external surface of the cell membrane

Cell surface receptor that binds to various ligands (e.g., integrins, syndecans, & CD97). The activation of this receptor stimulates signaling pathways that are mainly involved in cell adhesion and migration.

Recognized by the ISCT committee

[15,16,17,18,19,20,21,22]

3

CD105

(TGF-βR3)

Endoglin

or

Transforming growth factor β receptor type 3

Transmembrane glycoprotein

Auxiliary coreceptor for TGF-β1 and β3 ligands^**

Recognized by the ISCT committee

[23,24,25,26,27]

4

Sox2

Sex determining region Y-box 2

Nuclear transcription factor

interacts with Oct4 to form a binary complex that activates the transcription of several pluripotent genes and inhibits the transcription of several differentiation genes.

Member of the pluripotency triad

[28,29,30,31,32,33]

5

Oct4

Octamer-binding transcription factor 4

Nuclear transcription factor

1- interacts with Sox2 to form a binary complex that activates the transcription of several pluripotent genes.

2- interacts with Nanog to form a complex that activates the transcription of the Dnmt1 methyltransferase gene.

Member of the pluripotency triad

[9, 34, 46,47,48,49]

6

Nanog

Nanog

(from Irish mythology Tir nan Og = Land of eternal youth)

Nuclear transcription factor

Interacts with Oct4 to form a complex that activates the transcription of the Dnmt1 methyltransferase gene.^***

Member of the pluripotency triad

[35,36,37,38,39,40,41,42,43,44,45,46,47,48,49]

7

CD29

(ITGβ1)

Integrin beta 1

Transmembrane protein

associates with different integrin alpha subunits to form integrin complex receptors that contribute to various biological processes in different cells. In MSCs, it is mainly involved in cell adhesion and migration.

Widely used marker for perinatal MSCs

[50,51,52,53,54,55,56,57,58,59,60]

8

CD49f

(ITGA6)

Integrin alpha 6

Transmembrane protein

Sustains stemness of the cell by downregulating p53 expression.^****

Widely used marker for perinatal MSCs

[61,62,63,64,65]