The Institute of Biochemistry and Cell Biology of the Chinese Academy of Sciences ( abbreviated as the Institute of Biochemistry and Cell Research of the Chinese Academy of Sciences ) announced that the Zhoubo Research Group and the Zheng Junke Research Group of Shanghai Jiaotong University have published cooperation in the internationally renowned academic journal The EMBO Journal. The research paper reveals for the first time the important regulatory function of luteinizing hormone, which is secreted by human puberty, in the stable maintenance of hematopoietic stem cell numbers.
Like tumor cells, stem cells have the potential to proliferate in vivo. However, unlike tumor cells, the number of adult stem cells in each tissue is in a state of strict regulation. Hematopoietic stem cells in the bone marrow are the primary progenitor cells responsible for the production of all blood cells in the human body. Studies have shown that after birth, hematopoietic stem cells in the bone marrow enter a high-speed expansion phase, and with the onset of puberty, this development progresses into the "brake brake" phase, and the number of hematopoietic stem cells begins to gradually stabilize. However, to date, scientists are still ignorant of how the body regulates the number of these adult stem cells, and the biological significance of this quantitative regulation is even more inconspicuous.
Luteinizing hormone is a hormone secreted by the pituitary gland since puberty. Its "work" is involved in regulating the maturation of the reproductive system, but in this study, researchers have discovered another function of luteinizing hormone - - Regulate the number of hematopoietic stem cells in adolescent mice and maintain the stability of hematopoietic stem cells. Studies have shown that the ability of bone marrow hematopoietic stem cells to induce luteinizing hormone increases exponentially during puberty. The researchers further found that the "receptor protein" that induces luteinizing hormone is directly expressed on the cell surface of hematopoietic stem cells. Once hematopoietic stem cells lose their "induction" to luteinizing hormone, they will continue to expand during puberty, eventually leading to excessive hematopoiesis and leukocytosis in the bone marrow, which is followed by an acceleration of the leukemia process.
Subsequently, animal experiments showed that if the hematopoietic stem cells of mice could not "sensitize" to the pubertal luteinizing hormone by genetic modification, the hematopoietic stem cells in the mouse bone marrow would be over-expanded, and the peripheral blood leukocytes increased abnormally, which directly proved Luteinizing hormone plays a key role in regulating hematopoietic stem cell function. In addition, the researchers also found that blocking the luteinizing hormone signal will accelerate the onset of leukemia.
It is reported that this work reveals a hidden biological clock in the body: once hematopoietic stem cells enter puberty, they will be "emergency braking". If this "brake" is broken, it will cause blood diseases and even leukemia. How to use this "brake system" to intervene or prevent the leukemia process remains to be further studied by scientists.