Adult (or somatic) stem cells are a type of cells found in organs and tissues of the human body (including the umbilical cord and placenta, just after birth), that have a potential of self-renewal and are able to transform into other types of specialized cells.
What is the function and capabilities of adult stem cells?
The stem cells of an adult human body ensure its normal development, take part in the regeneration of diseased, damaged or worn tissue. Having received a signal that is provoked by any tissue damage or illness, these stem cells begin to divide into the daughter stem cells (one of them remains the stem cell, and the other becomes specialized).
Then, they turn into the cells of damaged tissue and thus restore the balance of an organism. When the tissue runs out of stem cells, then the body sends special bone marrow stem cells to it.
The differentiation potential of adult stem cells is more limited compared to that of embryonic cells (this means that they are able to produce fewer different types of cells). Typically, somatic stem cells generate various cell types for a particular type of tissue or organ in which they are located.
For instance, HCSs (hematopoietic stem cells) are able to give rise to red blood cells, white blood cells, and platelets. Though HCSs cannot generate, let’s say, liver or lung cells.
What are the types of adult stem cells?
These cells can be divided into three main groups:
- hematopoietic (giving rise to all blood cells);
- multipotent mesenchymal (or stromal, that able to differentiate into osteoblasts (bone tissue cells), chondrocytes (cartilage cells), adipocytes (fat cells), cardiomyocytes, nervous tissue, hepatocytes);
- tissue-specific progenitor cells (located in various tissues and organs and responsible for renewing their cell population, that is, they replace dead cells).
Sometimes umbilical cord blood cells are isolated into a separate group of adult stem cells since they are the least differentiated of all cells of a mature organism, that is, they have the highest differentiation potential.
Cord blood stem cells are used to treat more than 70 different diseases, mainly leukemia and other diseases of the blood-forming organs.