I’d like to start the series of posts dedicated to mesenchymal stem cells (MSC) definition and assays. The controversy persists in the field, because there is no agreement about proper definition of MSC among professionals. I hope this series of posts will spark discussion and help us to clarify some issues.
Today I’d like to focus on historical aspects of defining the term of MSC.
Alexander Friedenstein in his earlier series of work in 60-70s identified new kind of clonal osteogenic progenitors in bone marrow stroma. He started to use the term: “osteogenic stem cells“. Later he was able to show that single stromal cell can give the colony- forming unit-fibroblast (CFU-F), the clonal progeny of which can give multiple skeletal tissues.
He created a concept and proposed the term of “stromal stem cells“. Today he widely credited for discovery of a new (second) type of bone marrow stem cells, different from hematopoietic.
In 1991 Arnold Caplan proposed to apply the term “mesenchymal stem cells” to the type of cells, described by Friedenstein group. This term became widely adopted, especially after the “human study” by Mark Pittinger and colleagues, published in 1999.