Human stem cells can be divided into three categories.
At present, there are three key areas of stem cell research: adult stem cells, embryonic stem cells and induced pluripotent stem cells. Around the world, researchers are investigating the possible stem cell solutions and cures for some life threatening diseases like Lou Gehrig disease, blood disorders and heart disease.
According to some researchers, supplementation of any surgery with stem cell treatment can help patient heal rapidly. Most researchers believe that adult stem cells are promising and less controversial than embryonic stem cells.
Here are some basic facts that you need to know about adult stem cells:
1. Stem cells never truly shut down – Stem cells, the unspecialized cells, have the capability of renewing themselves by the process of cell division. They can regenerate even after years of inactivity. They can regenerate even after years of inactivity.
2. Stem cells can virtually divide into any cell type – Under specific experimental or physiologic conditions, stems cells can be induced to transform into virtually any tissue or organ specific cells. This process can be carried out in laboratory and can also take place naturally in the body – in bone marrow, gut and even in organs like the heart.
3. Adult stem cells are present in several places in the body – Research on adult stem cells dates as far back as the 1950s, when researchers discovered that bone marrow had at least two types of stem cells: hematopoetic stem cells, responsible for formation all types of blood cells and mesenchymal stem cells, which can generate fat, bone and cartilage cells.
Later in the 1990s, scientists discovered that even brain, the highly specialized organ of our body, contained stem cells.
These stem cells reside in specific areas called ‘stem cell niche‘.
4. The number of stem cells declines as you age – In every tissue, a specific number of stem cells are present that is very small as compared to the number of cells that make up the body.
According to surgeon C. Thomas Vangsness, ‘Your body has 70 to 100 trillion cells. About one in a million cells are specialized stem cells, maybe one in 100,000 if you are younger.’
Once the stem cells are removed from the body their capability to divide is limited which presents a major problem when the scientists need to generate large quantities of stem cells.
Scientists are trying to rectify this problem and to manipulate the stem cells to form specific cell types so that they can be used to treat disease or injury.
5. Trans-differentiation – As per various experiments conducted, certain adult stem cell types can differentiate into cell types seen in organs or tissues other than those expected from the cells’ predicted lineage, eg., blood-forming cells that differentiate into cardiac muscle cells or brain stem cells that differentiate into blood cells, and so forth.
Making use of this phenomenon, scientists are now trying to reprogram the available stem cells into other cell types which might well have been lost or damaged in the individual due to disease.
6. Stem cells can revolutionize transplantation – Adult stem cells are believed less likely to induce transplantation rejection as patients own cells are grown in culture media and then reintroduced in him. This is particularly advantageous as immunosuppressive drugs can be circumvented, which themselves have deleterious effects.
There are few other sources of adult stem cells including adipose tissue, umbilical cord blood and tissue, placenta, and amniotic fluid. For allogenic transplantations stem cells from umbilical cord blood and tissue are believed to be carrying minimal to no risk of rejection due to their lack of specific surface antigens.
Our immune system recognizes the foreign bodies based on these surface antigens so these premature cells lacking the surface antigens can escape the host’s immune system.
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