Combined omics analysis identifies transmembrane 4 L6 family member 1 as a surface protein marker specific to human mesenchymal stem cells.

Mesenchymal stem cells (MSCs) are promising for cell therapy and regenerative medicine; but their lack of specific markers renders the cell culture at potential contamination risk with other cell types, in particular, fibroblasts. In this study, we mapped 2 differential transcriptome data of MSCs compared, one to mononuclear cells and the other to fibroblasts, onto the membrane proteome data, the analysis of which led to an identification of transmembrane 4 L6 family member 1 (TM4SF1) as a surface protein marker candidate that could discriminate MSCs simultaneously from blood cells and fibroblasts. Our analyses confirmed that TM4SF1 was abundantly expressed on MSCs but neither on other blood/tissue cells nor on fibroblasts.

Cytokine secretion profiling of human mesenchymal stem cells by antibody array.

Mesenchymal stem cells (MSCs) provide not only cell sources for connective tissues but also the control of hematopoiesis and immune response. A multitude of cytokines and growth factors secreted from MSCs are known to confer such multifunctional functionality, but their overall spectrum and the respective expression strength have not been thoroughly illustrated. In this study, we have obtained the comprehensive cytokine secretion profile of human bone marrow (BM)-derived MSCs, with the use of an antibody array recognizing 120 cytokines and chemokines.

Gene and microRNA expression signatures of human mesenchymal stromal cells in comparison to fibroblasts.

Human mesenchymal stromal cells (MSCs) offer great hope for the treatment of tissue degenerative and immune diseases, but their phenotypic similarity to dermal fibroblasts may hinder robust cell identification and isolation from diverse tissue harvests. To identify genetic elements that can reliably discriminate MSCs from fibroblasts, we performed comparative gene and microRNA expression profiling analyses with genome-wide oligonucleotide microarrays. When taken globally, both gene and microRNA expression profiles of MSCs were highly similar to those of fibroblasts, accounting well for their extensive phenotypic and functional overlaps.

Fibroblast activation protein alpha identifies mesenchymal stromal cells from human bone marrow.

Mesenchymal stromal cells (MSCs) have gained widespread popularity in cell therapy, but their development into clinical products has been impeded by the scarcity of cell-specific markers. We previously explored transcriptome and membrane proteome of MSCs, from which fibroblast activation protein alpha (FAP) was recognized as a prime surface marker candidate. The present study showed that FAP was constitutively expressed on MSCs, but not on other cells.