Mesenchymal stem cells
Specialized cells can divide. But are the result of cell division with exactly the same functions that were inherent to the cell-predecessor. More recently, it was thought that tissue repair after injury is carried out by the division of specialized cells.
And only in the light of the latest research it was found that the growth of tissues, their constant update and recovery occurs due to special cells called stem.
They do not have any specific features and differences. Depending on the conditions in which they find themselves, stem cells can transform into specialized cells of organs and tissues.
Community stem cells as uniform in appearance, and the ability of individual cells to differentiation (manifestation of properties and functions of specialized cells). The most pronounced ability to form almost any body cell endowed with stem cells isolated from tissues of embryos.
Only here to use them the majority of scientists refuses, as it is associated with a large number of ethical standards, and in some countries, and restrictions on conducting such experiments at the legislative level.
Then, in their activity and ability to form different types of specialized cells, followed by cells from umbilical cord blood, the umbilical cord and placenta.
Already here they often have their primary specialization:
- hematopoietic stem cells are involved in the formation of red blood cells, their development in the laboratory can still be sent in the direction of education neurocyton or connective tissue cells, but these cells are often only resemble specialized cells and cannot perform all their functions;
- mesenchymal stem cells give rise to cell lines adipose, bone, lung, liver, cartilage, bone and other tissues.
The use of hematopoietic stem cells has no to Kogon is news. The presence of HSC in the bone marrow after transplantation in the recipient’s body (the patient, which transplanted donor bone marrow) restore hematopoiesis in patients with leukemia, leukemia and other blood diseases.
The study of mesenchymal stem cells and their use for the treatment of various diseases has begun relatively recently. A number of studies have reached a phase when mesenchymal stem cells were injected people with various diseases. But none of the methods have not received wide distribution.
The sources of material
In adults, a number of such cells can be identified from:
- red sluggish brain;
- subcutaneous fat;
- the blood taken from a vein.
There are mesenchymal stem cells in virtually any tissue, but of the three above places to of the easiest. A sample of bone marrow taken from the iliac wing (one of the bones of the pelvis) bones. This requires the holding of local anesthesia. At the injection site remains the only needle mark that heals without a trace.
To obtain a sufficient amount of adipose tissue is also is not difficult. This can be done during the procedure or liposuction through small incisions in the thigh or stomach. The contents of stem cells in adult tissues is only from 0.001 to 0.01%.
But this small number is not a problem for scientists, as stem cells that are placed in the special conditions, continuously divided. This means that in the laboratory it is possible to obtain a sufficient amount of material.
Video: What are stem cells
How to operate the MSC?
The maximum concentration of mesenchymal stem cells found in the bone marrow. If progenitor cells, which are located directly in the tissues is insufficient, a number of them comes out of the tap brain and in the blood stream migrate to the injury site.
Reaching the goal, they are fixed in the tissues began to share. When the number of newly formed cells is sufficient to restore the damaged tissues, from stem cells spontaneously transformed into specialized, specific on.
As in the damage are also mesenchymal in addition to hematopoietic stem cells, aktiviziruyutsya the process of increasing the number of vessels needed to improve blood supply to the tissues.
Mesenchymal not only actively share. They also secrete large amounts of biologically active substances which accelerate the reactions of metabolism in tissues, activates the existing highly specialized cells.
For example, the introduction of only 3% grown from stem cells to hepatocytes in the liver tissue, diseased cirrhotic process, leads to a significant relief of the patient.
There are two reasons:
- new young cells actively divide and perform their functions;
- introduced cells secrete a substance that activates its own liver cells.
Effect on the immune system
We should also mention the ability of mesenchymal stem cells to suppress the activity of the immune system.
Usually the main problem of transplantation is:
- reaction «host versus graft» when the immune system «attacks» the transplanted organ or tissue;
- reaction «transplant against host», when the transplanted bone marrow cells, begin to «fight» with the recipient’s body.
Transplanted mesenchymal stem cells inhibit the activity of T-lymphocytes, key cells of the immune system of the recipient, which are responsible for recognition of foreign agents.
Thanks to this transplanted stem cells reproduce and differenziata, replacing the damaged cells of organs but do not cause rejection reactions.
But if the risk of rejection is reduced or reduced to zero, there is no problem in the selection of donors, you can take stem cells from any donor and transplanted to any recipient. The most optimistic forecasts of scientists in the future transplantation will become as easy as buying drugs in a pharmacy.
What can be treated
Currently using mesenchymal stem cells have successfully treated diabetes type 2 diabetes. Being developed for the treatment of diabetes mellitus type 1. In many cases, thanks to scientists transplant lab-grown cells of the islets of Langerhans (the part of the pancreas responsible for insulin production) managed to establish the production of insulin in the body, reduce insulin resistance and normalize blood sugar.
- Treatment of liver diseases.
Research in this area are conducted in two directions. The first is transplanting propagated in the laboratory of liver cells. The second is the growing body directly in the laboratory, and then transplanting it into the patient’s body.
- The restoration of the structure and function of the heart.
Transplantation of mesenchymal stem cells is now used as one of the stages of a number of heart operations, such as restoration of patency of the valves, the elimination of insufficiency of heart valves, closure of the oval window, and so on.
- The restoration of joint cartilage and bone.
To restore articular cartilage are two main methods of stem cell transplantation. The first involves the introduction of stem cells directly into the joint cavity by means of injection. The second method is more time-consuming: articular cartilage grown in the laboratory, and then in the plate is transplanted to the site of the destroyed sections.
Naturally, the possibility of transplantation of stem cells does not end, but the rest of the study this case in more distant future.
The role of MSCS in the development and maintenance of neoplastic processes in the body
If we are talking about cancer and participation in the development of neoplastic processes of mesenchymal stem cells, it is necessary to recall two models that are the key:
- the model of cancer stem cells;
- a participatory model of normal stem cells in the processes of growth of tumors and formation of metastases.
Cancer stem cells
There is no doubt that any tumor grows from a single cell. This cage is nothing more than a stem cell, genetic machinery that has been damaged by any of the influences (chemical, viral agent, etc.). Such a «defective» cell at the initial stage, gives an unlimited growth of abnormal tissue. In this part of the newly formed cells remain stem without any specific functions, and part differentialsa and lose the ability to unlimited growth.
The importance of the model of cancer stem cells in which scientists have had the opportunity to explain why after many years after treatment may begin to grow again, and why is it so difficult to fight metastases and the metastasis of the tumor.
On the basis of this model is now being developed, such treatments that will kill not only differentiated tumor cells but also the stem cells, which began the cancer growth.
Influence on tumor growth
As we have already mentioned above, stem cells not only actively share, but also produce a number of substances that accelerate the growth of blood vessels, metabolism in the tissues, inhibit the immune response. All of this may ultimately contribute to tumor development and active dissemination.
In animal experiments the introduction of the melanoma cells (one of the most malignant types of cancer) into the bloodstream together with mesenchymal stem cells accelerate the development of cancer process in the body, quickly leading to death.
Mesenchymal stem cells in cosmetology
Now, even in Russia there are companies that are engaged in transplantation of stem cells to rejuvenate. This technique is often presented as advanced science technology, the first step in providing the people of immortality.
Having tried all cosmetics and cosmetic techniques, each of the people coming to the realization the necessity of «aging beautifully» or to resort to plastic surgery. And there is often a desire to abandon a proven, but traumatic and painful method of rejuvenation, which is a plastic surgery in favor of multiple superficial injections, which they will bring directly into the skin.
By agreeing to these procedures, you must understand that at the present time the practical use of stem cells ahead of the work on their research and study. It is possible that the introduction of his own person reproduced in the laboratory stem cells, will not bring harm. But just as possible that the doctor will put you on a kind of an experiment, introducing the drug, which has not been studied, and which can give very different results, including unexpected for the doctor.
The main risk associated with the cultivation of mesenchymal stem cells is that in the unusual environment of stem cells even with a normal genotype can undergo oncogenic transformation.
To run such a risk can be the case when there are significant defects of the skin formed on the burn or injury, when to close the defect using other methods is not possible.