We are now increasingly able to comprehend what happens due to the shortening of the telomeres in the cell caused by aging and the resulting loss in functioning and regeneration potential of the stem cells. Our ideal aim is to slow down the aging process and to improve the regeneration potential of the aging organism as well as to prevent increased tumor development. To do this, we need to break down these processes in detail and understand the function of stem cells in the aging process. This knowledge should help us find out how to steer the various signal proteins “intelligently” to our benefit.
Stem cells are an important area of research. In Germany, scientists are concentrating more and more on adult stem cells due to the ethic qualms about using embryonic stem cells. However, the issue of ethics is not the only problem with embryonic stem cells. Because of their capability to differentiate into all types of tissue and cell, they theoretically offer huge application potential. In reality, however, it is difficult in clinical applications to get the embryonic cells to the right place, to make them produce only the desired cell type and not cause any unwanted degenerations.
It could therefore be an advantage for scientists to use their own organ-specific stem cells. Firstly, these adult stem cells are already at the place where they are needed, and secondly, they can only differentiate into a few organ-specific cell types. This reduces the probability of cell degeneration.
In hospitals, this possibility is already being used by transplanting patients’ own or foreign hematopoietic stem cells. Chemotherapy and radiation used to treat cancer also kill off other frequently dividing cells such as hair cells and those of the immune and hematopoietic system. The stem cells are taken from the patient before treatment and given back afterwards to restore the function of the immune and hematopoietic system.
This is also how, for example, leukemia is cured, by doctors transplanting bone marrow stem cells from a healthy donor. This method of stem cell transplantation is intrinsically quite easy, as the cells can be distributed via the bloodstream. However, it is not as easy to do in solid organs such as the liver. It would be a great advantage here to be able to use stem cells of the organ itself.
Telomeres are not the only reason for aging. It is also caused by substances naturally produced in the body such as soluble factors, cytokines and hormones circulating in the blood. As we grow older, there are changes in the way they are released and in the ability of our body to react. This leads to a deterioration of the function of the cells or whole organs. This is another area that needs researching in more detail. As such endogenous substances are detectable in our blood, they have the potential to serve as biomarkers, giving us information on the “age” of an organ or the whole organism.