How do stem cells turn into other cells?
I cannot find a reputable source!!! Some sites say that they need to be programmed, some say that a way hasn't been discovered, my brother thinks the stem cells either get "orders" (fetus) or change after put next to another cell.
I did find an article that said that stem cells are present in menstrual fluid... Does this mean that there could be a way I could use my period to heal my acne scars? How would I do this? I know it's a little vulgar, but acne scars suck!
Update:But how does a stem cell BECOME a different cell? You completely missed my question
Comments
I am a biology major and from what I understand scientists do not entirely understand how a stem cell becomes differentiated. However they still know a lot about what is happening! There is often a change in the epigenetics of a cell. What does this mean? Basically not all of the genes inside of a cell are being transcribed and different cells transcribe different genes more than other genes. The cell has what are called histone proteins that wrap around the DNA. The cell can modify the histone proteins which results in the DNA being coiled tighter. If the DNA is coiled to much then the DNA can not be transcribed. So as cells differentiate different parts of the DNA is coiled in different areas resulting in different cells. By only using certain genes a cell will be different from another cell that uses different genes.
How does a certain cell know which type of cell to turn into? That is what scientists are not entirely sure about. They believe that for the most part the cells respond to different signals. Different signals will result in the cell differentiating into a specific type of cell. The signals could be directly from neighboring cells (what your brother thinks), or the signals could be sent from a far away cell. These signals "program" the cell and let it know which type of cell to become.
Another thing to realize is that there are lots of different types of stem cells. There are totipotent (potential to become anything) stem cells. These cells can be come any type of cell in the body (embryonic stem cells). These totipotent stem cells divide and make more stem cells. These stem cells however might only be able to become connect tissue cells and not neurons. However these stem cells could become osteoblasts, fibroblasts, adipocytes etc. These types of stem cells are called pluripotent (potential to become many things). These stem cells make other stem cells that have less and less capability of becoming other cells until eventually they are still stem cells but they can only become one type of cell. For example there are skin stem cells that no matter what will only make skin cells. This the type of stem cell in the menstrual fluid. So even though it is a stem cell it can only become one type of cell (probably uterine lining) and would not be able to fix your acne scars
as you know, stem cells can develop into the various tissues that our body needs. differentiation, the process of becoming a 'mature' cell involves a lot of different factors, genetics, mutations, growth factors, position of the cell at a specific time of development, etc.
before the formation of a blastocyst, the cells are already positioned according to the planes of the cluster of cells. so, from early on, growth factors, hormones, other proteins are already converting the very first stem cells to cells that are beginning to differentiate.
as we age, we lose the quantity of stem cells in our bodies due to changes in hormonal or growth factor concentrations.
"Stem cells can give rise to specialized cells. When unspecialized stem cells give rise to specialized cells, the process is called differentiation. While differentiating, the cell usually goes through several stages, becoming more specialized at each step. Scientists are just beginning to understand the signals inside and outside cells that trigger each stem of the differentiation process. The internal signals are controlled by a cell's genes, which are interspersed across long strands of DNA, and carry coded instructions for all cellular structures and functions. The external signals for cell differentiation include chemicals secreted by other cells, physical contact with neighboring cells, and certain molecules in the microenvironment. The interaction of signals during differentiation causes the cell's DNA to acquire epigenetic marks that restrict DNA expression in the cell and can be passed on through cell division." quote from bottom web site
Stem cells are the body's raw materials — cells from which all other cells with specialized functions are generated. Under the right conditions in the body or a laboratory, stem cells divide to form more cells, called daughter cells. These daughter cells either become new stem cells (self-renewal) or become specialized cells (differentiation) with a more specific function, such as blood cells, brain cells, heart muscle or bone. Stem cells are unique — no other cell in the body has the natural ability to generate new cell types.
Cell-cell signaling and consequent internal biochemical pathways that activate/inactivate various transcription factors that regulate gene expression of certain genes.
For example, erythropoietin is what's responsible for causing a common myeloid progenitor (an adult stem cell in the bone marrow) to differentiate into an erythrocyte (red blood cell).
Stem cells can turn into a variety of different cells by the process of "differentation". In a way, they are being programmed!
hope this helps!