Other researchers have been able to isolate stem cells from the brains of dead people and grow them in the laboratory; Not only in embryos
by Yanai Ofran *
On the card of the Association for the Promotion of Transplants in Israel (AD), the potential organ donor is invited to mark the organs he is donating. It may soon be necessary to reprint these cards and add, between the cornea and the heart, another option - a brain. This is one of the conclusions of a scientific discovery published this week: a team of doctors and scientists from California managed to isolate stem cells from the brains of dead people and grow them in the laboratory.
Stem cells are the blockbuster hit in biotechnology. These are omnipotent cells capable of developing into different types of tissues. The ultimate stem cell is, of course, a fertilized egg, from which all cell types develop. But over the years several other types of stem cells have been discovered. In the bone marrow, for example, there are cells that can become red blood cells, white blood cells or any other type of blood system cells or immune cells.
The hopes placed by researchers in stem cells can surprise even those with a developed imagination. One of the proposals, for example, is to use these cells to grow organs for transplantation in the laboratory. Meanwhile, until these ideas mature, doctors and researchers are conducting experimental treatments using stem cells taken from fetuses after abortions. Transplants of stem cells from the brains of fetuses have already been performed in Parkinson's patients and stroke victims, and there are plans to transplant such cells in Alzheimer's patients as well. The idea is simple - various diseases cause the inevitable death of brain cells. The stem cells will be able to reach the damaged place and replace the dead cells. Thus, the researchers hope, it will be possible with a simple operation to cure paralysis, cognitive impairments and also Alzheimer's or Parkinson's.
Diabetes can be a result of pancreatic cell death. Even in this type of diabetes there are those who suggest treating it with the help of stem cells. In recent weeks, it has even been reported that stem cells are being used to repair the damage left behind by heart attacks. Almost every day a new idea for possible uses of stem cells is published in the medical press.
But the opposition to this technology is imbued with a fervor that is no less than that of the supporters. Almost all new treatments use stem cells of embryonic origin.
The deadly confluence of revolutionary medical care, genetic engineering and abortion has conservative politicians and ethics experts on their toes. Different parliaments in the world are at different stages of legislation designed to limit, if not completely ban, research in embryonic stem cells.
This is one of the reasons for researchers' desperate search for other places where evolution has hidden stem cells. This week it seems that the search ended successfully. Researchers from California managed to isolate stem cells from the brains of dead people, and researchers from New York and Yale University located omnipotent cells in the bodies of adults.
One of the revolutionary discoveries of recent years was the fact that the adult brain has brain stem cells. Although these are cells with limited developmental potential (they cannot become pancreatic cells or skin cells), they are capable of becoming any type of brain cell (and there are dozens of types of brain cells).
The team that conducted the study, led by Theo Palmer, was able to isolate such cells from the brains of people who had died and grew them in laboratory cultures. The cells multiplied at a rate similar to that of stem cells from fetal brains. In one case, the researchers were able to isolate stem cells from the brain two days after death. In an article published in the journal Nature, the researchers admit that it is still unclear whether the cells isolated from the dead will have as high a therapeutic potential as fetal cells. Meanwhile the results are visible
promise
The second study, which was reported this week in the journal "Cell" is much more surprising. The researchers, led by Diane Kraus, tried to locate stem cells in the bodies of adult mammals. A difficult debate has raged in recent years surrounding the question of whether an adult's bone marrow contains omnipotent stem cells, that is, stem cells that can become not only any blood cell, but also a liver cell, a lung cell, or a skin cell. It is difficult to decide the debate because even if there are such cells in the bone marrow, they are very few and difficult to locate. Kraus' team was able to locate such cells in mice. According to the prevailing theories in developmental biology, it is very likely that these results are also true in relation to humans.
Kraus and her colleagues took bone marrow cells from a male mouse and transplanted them into the bone marrow of female mice. The transplanted cells had Y chromosomes, found only in males, and thus it was possible to track them. The researchers hypothesized that the non-stem cells would exit the bone marrow into the circulation and disappear over time. Male cells that would eventually remain in the bone marrow, they hypothesized, would be the stem cells. After a long period of time, the researchers isolated from the bone marrow of one of the mice a male cell that was suspected to be a stem cell. This cell was transplanted into another mouse. After a few months, male cells were discovered in the liver, lungs, digestive tract and skin of the same mouse. These were the descendants of the stem cell implanted in her bone marrow.
The surprising conclusion of this study is that in the body of adult mammals, stem cells with great developmental potential can be found. But in order to control them (for example, to use them in gene therapy) you need to understand what exactly they do in the body of an adult, and that will probably take at least a few years.
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