Have you ever wondered how stem cells injected into the body know precisely where to go in the body for healing and regeneration?
Here is an abstract from Giselle Chamberlain, et al, from Leopold Muller Arthritis Research Centre, School of Medicine, Keele University, Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry, Shrops, United Kingdom. The title of this paper – quite a mouthful – is, “Concise Review: Mesenchymal Stem Cells: Their Phenotype, Differentiation Capacity, Immunological Features, and Potential for Homing”
Here’s a small portion: “MSCs [the abbreviation of "mesenchymal stem cells"] are nonhematopoietic stromal cells that are capable of differentiating into, and contribute to the regeneration of, mesenchymal tissues such as bone, cartilage, muscle, ligament, tendon, and adipose. MSCs are rare in bone marrow, representing 1 in 10,000 nucleated cells. Although not immortal, they have the ability to expand manyfold in culture while retaining their growth and multilineage potential.” This is extremely important. They don’t live forever, that’s true, but they can reproduce themselves accurately and dramatically increase their numbers in the lab, which is almost the same thing.
How do you know you’ve got the right type of stem cells? “MSCs are identified by the expression of many molecules including CD105 (SH2) and CD73 (SH3/4) and are negative for the hematopoietic markers CD34, CD45, and CD14.”
Now, this is the fascinating part: “The properties of MSCs make these cells potentially ideal candidates for tissue engineering. It has been shown that MSCs, when transplanted systemically, are able to migrate to sites of injury in animals, suggesting that MSCs possess migratory capacity. However, the mechanisms underlying the migration of these cells remain unclear. Chemokine receptors and their ligands and adhesion molecules play an important role in tissue-specific homing of leukocytes and have also been implicated in trafficking of hematopoietic precursors into and through tissue. Several studies have reported the functional expression of various chemokine receptors and adhesion molecules on human MSCs. Harnessing the migratory potential of MSCs by modulating their chemokine-chemokine receptor interactions may be a powerful way to increase their ability to correct inherited disorders of mesenchymal tissues or facilitate tissue repair in vivo. The current review describes what is known about MSCs and their capacity to home to tissues together with the associated molecular mechanisms involving chemokine receptors and adhesion molecules.”
As clearly shown in this report, Mesenchymal Stem Cells have an internal homing device which will direct the stem cells to a specific area in the body, no matter where they are injected.
Even though it’s not entirely clear how or why it works the way it does, we know that it DOES work, and that further stem cell research will only lead to more practical uses for these safe and powerful cells.