Physiological Changes: Stem Cells

If one of the major causes of mesenchymal tissue aging is the decreased availability of mesenchymal stem cells, an obvious quick-fix would be to obtain some marrow, and then isolate and culture-expand the mesenchymal stem cells. It has been shown that mesenchymal stem cells can be culture-expanded one billion-fold without affecting their differentiation potential. With this large number of cells, it would seem possible to merely add these cultured mesenchymal stem cells back to blood-stream marrow and other sites serviced by the blood supply, and thereby raise the body level of mesenchymal stem cells. However, although some mesenchymal stem cells that are put back into the blood stream do make it back into the marrow compartment, relatively few do so. Consequently, increasing the body's load of mesenchymal stem cells requires understanding how the cells target to particular locations along the blood-vessel pathways, and then to efficiently transport the cell through the wall of the blood vessel into the tissue. Alternately, by genetically adjusting the mesenchymal stem cells in culture to fix or replace mutated genes, it may be possible to improve the fabrication capacity of the differentiated progeny to maintain tissue integrity and counteract aging-related tissue destruction. Even if these therapeutic approaches fail, it is clear that management of mesenchymal stem cells can have profound effects upon the aging process.