Epidermis Growth Factor promotes bone marrow recovery
Hematopoietic (hematopoietic) cells of the bone marrow, whose function is to constantly renew blood cells, are very sensitive to the effects of radiation. Protecting these cells or accelerating their recovery can help improve the condition of patients who have undergone bone marrow transplantation or radiation during antitumor radiotherapy, as well as those exposed as a result of an accident.
Unexpectedly, Duke University researchers working under the guidance of Professor John Chute have found that the hematopoietic cells of genetically modified mice, whose bone marrow is characterized by excessive synthesis of epidermal growth factor, are protected from the harmful effects of radiation.
At the beginning of their work, the authors used mice with the deletion of two genes that control the death of endothelial cells lining the inner surface of blood vessels. It is believed that these cells are involved in the management of hematopoietic cells. The blood vessels and hematopoietic system of such mice suffered less from exposure to high doses of radiation, which improved the survival of animals.
Analysis of the secretion released by the endothelial cells of the bone marrow of such animals showed that the content of epidermal growth factor in it exceeds the indicators characteristic of ordinary animals by 18 times. After receiving these unexpected data, the authors decided to test whether the epidermal growth factor could directly stimulate the division of hematopoietic cells in the bone marrow of irradiated mice. It turned out that the proliferation stimulated in this way provides a population of cells that successfully restore the hematopoiesis of animals whose bone marrow was previously destroyed by radioactive irradiation.
After that, the authors conducted a series of experiments in which they injected animals prepared for bone marrow transplantation with three variants of cell populations. One group of mice was injected with ordinary bone marrow cells, the second group – bone marrow cells of animals previously irradiated and injected with epidermis growth factor; and the third group – bone marrow cells of irradiated animals injected with saline solution.
The best results of bone marrow restoration were observed in the first group of animals. At the same time, the administration of epidermis growth factor to irradiated donors increased the rate of engraftment of their cells in the bone marrow of recipients by 20 times, compared with the introduction of saline solution.
Additional experiments showed that the introduction of epidermal growth factor improved the survival of animals exposed to a high dose of radiation. Thus, in the group of mice that received an injection of epidermal growth factor after irradiation, 93% of the animals survived, whereas in the control group that received an injection of saline solution, only 53% of the animals survived.
According to Professor Chute, apparently, the epidermis growth factor, whose effect on the vital activity of hematopoietic cells was not previously known, suppresses the activity of the PUMA protein, which usually triggers cell death after exposure to radiation.
Chute notes that to date, only the first steps have been taken to understand the mechanisms by which the epidermal growth factor stimulates the proliferation of hematopoietic cells, but the results indicate that in the future it may become a means to accelerate the restoration of the hematopoietic system in cancer patients who have undergone chemotherapy or radiotherapy.
Article by Phuong L Doan et al. Epidermal growth factor aids stem cell regeneration after radiation damage is published in the journal Nature Medicine.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on Medical Xpress materials:
Epidermal growth factor aids stem cell regeneration after radiation damage.
06.02.2013