Unipotent, Multipotent,Pluripotent and Totipotent Stem Cells
UNIPOTENT
While researchers have focused attention more closely on totipotent and pluripotent stem cells, unipotent stem cells have not received the same attention and research. However they have vast potential to treat serious health conditions. A unipotent stem cell refers to a cell that can differentiate along only one lineage. The word 'uni' itself is derived from the Latin word 'unus,' meaning one. Found in adult tissues, a unipotent stem cell, in comparison with other types of stem cells, has the lowest differentiation potential. This means that the cell has the capacity to differentiate into only one type of cell or tissue, which is lower in potential compared to stem cells that give rise to a broad range of cell types. Although the unipotent adult stem cells in the body's tissues will only give rise to one cell type, they still have the important property of self-renewal that is common in all stem cells.Despite their differentiation potential being limited, unipotent cells still have vast therapeutic potential to treat injuries and diseases.Unipotent Stem Cells are different from other stems cells due to a unique property of stem cells is their ability to differentiate, which means they can form specialized cells. Another special property is their ability to proliferate, or divide repeatedly. As mentioned, unipotent stem cells have a very limited ability to differentiate relative to other stem cells such as pluripotent, totipotent or multipotent cells. Their ability to self-renew, however, does make them a valuable candidate for therapeutic use in treating disease. They are thus able to generate healthy and viable cells for transplant purposes. Limitations of this technology,is that it is extremely time consuming. It can take several weeks to grow a sufficiently sized piece of skin. Skin is an initial barrier to disease so the pressure to promote healing and replace burned skin is high as well as very time sensitive. Improved research into the ideal conditions to encourage unipotent stem cell growth should hopefully ensure that the success of this form of therapy grows. |
MULTIPOTENT
A multipotent stem cell can give rise to other types of cells but it is limited in its ability to differentiate. These other types of cells are also limited in numbers. Examples of multipotent stem cells include those in the brain that give rise to different neural cells and glia or haematopoietic cells, which can give rise to different blood cell types, but they can't create brain cells. Bone marrow also contains multipotent stem cells that give rise to all blood cell types but not other cells.Hence, adult stem cells are considered multipotent because their specialization potential is limited to one or more cell lines. However, a multipotent stem cell known as a mesenchymal stem cell can give rise to several cell types. This particular stem cell has been found to give rise to bone, muscle, cartilage, fat, and other similar tissues. Multipotent stem cells are able to produce specific cell types. These vary from stem cells such as pluripotent ones which can give rise to almost any cell type, or totipotent ones which can give rise to any cell, including the potential to create a complete organism. Pluripotent stem cells undergo specialization into multipotent stem cells, and then multipotent stem cells give rise to cells with a specific purpose and function. Multipotent stem cells can be likened to a family-although they do give rise to different cells, the cells themselves are within a certain family and therefore, are closely related. |
PLURIPOTENT
Pluripotent stem cells have the remarkable capacity to grow into all of the different cells of the body. These cells can also be grown in the laboratory in a primitive undifferentiated state. While extremely valuable for research, controlling this incredible regenerative capacity is not straightforward. There are several key types of pluripotent stem cells:
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TOTIPOTENT
Totipotent stem cells are perhaps the most versatile of the stem cell types. A totipotent zygote cell is created when a single celled sperm and egg unite. A totipotent fertilised egg has the potential to give rise to virtually all human cells, such as nerve or heart. It is during the early cell divisions in embryonic development that more totipotent cells are produced. Within several days, these totipotent cells divide and create replicas, therefore producing more totipotent cells. It is after approximately four days that the cells begin to specialise into pluripotent cells, which can go on to specialise further but can't ever produce an entire organism as totipotent cells can. Basically, the pluripotent stem cell can do everything the totipotent one can except for creating an entire organism. |