A joint research group between Assistant Professor Yuya Kunizaki of the Graduate School of Medicine, Kyushu University and Albert Einstein Medical University (USA) can classify mesenchymal stem cells, which are the basis of bones, by gene and protein expression patterns. For the first time in the world, it was revealed that it produces different cytokines (substances for maintaining hematopoietic stem cells).This is said to have elucidated a part of the complicated maintenance mechanism of stem cells in the living body.
Stem cells are cells that have the ability to form all the cells and organs of living organisms.Organisms are born from a single cell (stem cell) in the early stages of development.Recent studies have revealed the existence of "organ-specific stem cells" capable of regenerating such organs not only in the fetal period but also in all adult organs.These cells have the ability to proliferate indefinitely throughout their lives, and many cells usually exist in a "sleeping state" and proliferate and differentiate as needed, such as during injury.
Stem cells can remain "sleeping" only in a special environment called a "niche."In human blood, there are cells (hematopoietic stem cells) that are the source of all blood cells, and they are mainly present in the bone marrow.The original mesenchymal stem cells, such as bone, were known as their "niche" cells, but the detailed mechanism was unknown.
This time, the mesenchymal stem cells that make up the "hematopoietic stem cell niche" can be roughly divided into two types of cells (NG2-positive cells and leptin receptor-positive cells) based on their distribution and expressed proteins, and these cells are each. It was found that they produce different cytokines and form different environments.This discovery is expected to contribute to the development of an efficient amplification method for hematopoietic stem cells and, by extension, the acceleration of regenerative medicine.
