LEARN ABOUT ORIGINAL CELL (Part 4)

Author: Dr. Tran Manh Hung , MA, STD
Original English

4. What are adult stem cells?

Adult stem cells are very different from those separated from embryos or fetuses and are present in developed tissues, for example in animals or humans after being born. It is possible to separate these cells from many tissues or organs, including the brain. However, the most common place they can harvest is from the bone marrow located in the middle of the bone tube.

Research and testing on adult stem cells has recently garnered much attention. Scientists discovered the presence of adult stem cells in many tissues, compared to what they previously knew. For example, blood stem cells usually only produce different types of blood cells. However, recent research has shown that some adult stem cells are more adaptable than previously thought. Adult stem cells extracted from mice (adults) can develop skin, muscle and liver cells. This finding led scientists to question whether adult stem cells could be used for transplantation. Although the results are unproven as well as not yet done with human cells. However, scientists are still trying to find a way to stimulate adult stem cells, or even other types of mature cells, to make them more flexible. If successful, the method will provide an additional source of unspecified stem cells.

Furthermore, recently a theory of 'stem cell differentiation' suggests that some adult stem cells may have the potential to produce other types of cells, more than what people still do. think before. This means that stem cells in the bone marrow, originally thought to be the only blood-producing cells, can contribute to the regeneration of damage to the liver, kidneys, heart, lungs and organs. other ruin. If it is possible to control the differentiation of adult stem cells in the laboratory, these cells could become the basis for therapies for treating many incurable diseases.

1. Skin cells are taken from the abdomen of the patient. The nucleus contains the DNA (the genetic basic component) of the patient, taken from skin cells.
2. The nucleus of a patient's cell is implanted in unfertilized egg cells, after the nucleus of the egg has been removed
3. Egg cells reproduce (exponentially) and form stem cells.
4. Stem cells are transferred to a culture plate so that they can develop into the types of cells that patients need to treat his disease, such as liver, nerve, heart, insulin cells. .
5. The cells are injected into the patient, to treat the patient's disease. The human body will not excrete these cells, because they contain his DNA (meaning that the cells all share the same type of DNA, which the immune system will accept).

In recent years, research in the area of ​​adult stem cells has grown tremendously. Adult stem cells can be recovered by tissue taken from patients, nourished in implants and stimulated to develop into a variety of adult cells. The use of stem cells for therapy, instead of embryonic stem cells, has many advantages and carries an important meaning in the field of science, morality and politics.

Generating stem cells from the patient's own tissue can completely eliminate the immune system (immune) problem.

Adult stem cells do not cause malignant tumors (teratomas). The application of adult stem cells in treatment has very few moral problems and completely avoids hot political debates. , related to the use of human embryos ⁵ .

Although this area is particularly attractive, it is also controversial in the scientific community and at the same time requires more thorough research to understand the full potential of mature, dense stem cells. especially compared to embryonic stem cells.

5. What potential do stem cells have?

Most specialized cells of the body cannot be replaced by natural processes if they are severely damaged or infected. Stem cells can be used to create specialized and healthy specialized cells, replacing diseased or malfunctioning cells.

Replacing diseased cells with healthy cells, called cellular therapy, is similar to organ transplantation, instead of organ transplants, only cell cultures are implanted. Some injuries or illnesses can be treated with a whole organ transplantation technique, while the number of people willing to donate is always lacking. Stem cells can be used instead and are a source of recovery for specialized cells.

Donor: Donor
Patient: Patient
Sexually produced totipotent cells (SPT): Total cell produced by reproductive processes
Specialized cells: Specialized cells
Therapeutic Tissue: Tissue for treating diseases
Somatic Cell Nuclear Transfer: Body cell transfer technique
Asexually totipotent cells (APT): The total cell produced without reproduction
Customized therapeutic tissue: Tissue for treating diseases as required

Currently, researchers are investigating the application of embryonic stem cells, fetal stem cells and adult stem cells to provide a source for many specialized cells, such as nerve cells and muscle cells. , blood cells, skin cells, to treat many diseases. For example, for Parkinson's, stem cells are used to create a special type of nerve cell that secretes dopamine (Dopa / dopamine: an abnormal amino acid used in the treatment of Parkinson's disease). These neurons, in theory, can be implanted into patients; where they will re-establish neural networks and rehabilitation, thereby treating the disease.

6. What obstacles must be overcome before the potential application of stem cells will be realized?

One of the first hurdles to overcome, is the difficulty of identifying stem cells in adult tissues that contain many types of cells. The process of identifying and cultivating the right kind of stem cells is often very rare in mature tissue, requiring an arduous process of research.

Second, when stem cells have been identified and removed from tissue, appropriate conditions are needed to stimulate them to differentiate into specialized cells. This work also requires conducting many experiments.

In general, embryonic stem cells and fetal stem cells are thought to have more uses than adult stem cells. However, scientists continue to study the appropriate conditions to differentiate specialized cell embryonic stem cells. Extremely fast growth characteristics of embryonic stem cells make scientists extremely cautious in the process of differentiating them into specialized cells. Otherwise any surviving embryonic stem cells can develop beyond control and tumor formation.

Even when overcoming all of these problems, new problems arise when specialized cells (from stem cells) are transplanted into the human body. They must combine with the person's tissues and organs to learn the necessary functions and get along with the body's natural cells. Cardiac cells, for example, work in culture environments, for example, and may not beat in the same rhythm as the transplanted heart cells themselves. The neurons implanted in the damaged brain are forced to connect to the brain's intricate cellular network to function properly.

However, there is still another challenge, which is the phenomenon of tissue removal. Like organ transplantation techniques, the body's immune cells will treat transplanted cells as "strangers", thereby creating immune reactions that make the transplant unsuccessful and possibly even harm the patient. Cell recipients (transplants) will have to temporarily take drugs to control their immune system, which itself is also very dangerous.

Indeed, research on stem cells and applications in the treatment of diseases is still only at the beginning. However, the results obtained on the study are very promising, researchers believe it is only a matter of time, until similar achievements are achieved for human stem cells.

---

Note:

⁵ . See Maureen L. Condic, 'The Basics About Stem Cells,' First Things (January 2002).

Tra Mi translates
Complete translation of Tran Manh Hung
Copyright © 2008 byTrần Mạnh Hùng

- Part 1 - Part 2 - Part 3 - Part 5 - Part 6