Self-renewal - the ability to go through numerous cycles of cell division while maintaining the undifferentiated state.The rigorous definition of a stem cell requires that it possesses two properties: In recent years the concept of adult stem cell has transformed to include the theory that stem cells reside in many adult tissues and that these unique reservoir of adult stem cells are not only responsible for the normal reparative and regenerative processes but are also considered to be a prime target for genetic and epigenetic changes culminating to many abnormal conditions including cancer. Consequently, more US government funding is being provided for adult stem cell research. The use of adult stem cells in research and therapy is not as controversial as embryonic stem cells, because the production of adult stem cells does not require the destruction of an embryo. Īdult stem cell treatments have been used for many years to treat successfully leukemia and related bone/blood cancers through bone marrow transplants. In mice, pluripotent stem cells can be directly generated from adult fibroblast cultures. Ī great deal of adult stem cell research has focused on clarifying their capacity to divide or self-renew indefinitely and their differentiation potential. Most adult stem cells are lineage-restricted ( multipotent) and are generally referred to by their tissue origin ( mesenchymal stem cell, adipose-derived stem cell, endothelial stem cell, etc.). Pluripotent adult stem cells are rare and generally small in number but can be found in a number of tissues including umbilical cord blood. Consequently, adult stem therapies require a stem cell source of the specific lineage needed and harvesting and or culturing them up to the numbers required is a challenge. Different types of adult stem cells are capable of transdifferentiation more than others, and for many there is no evidence of its occurrence. The ability of a stem cell of one lineage to become another lineage is called transdifferentiation. Adult stem cells, similar to embryonic stem cells, have the ability to differentiate into more than one cell type, but unlike embryonic stem cells they are often restricted to certain lineages. They have mainly been studied in humans and model organisms such as mice and rats.ĭue to the ability of adult stem cells to be harvested from the patient, their therapeutic potential is the focus of much research. Adult stem cells can be isolated from a tissue sample obtained from an adult.
Unlike embryonic stem cells, the use of adult stem cells in research and therapy is not controversial because the production of adult stem cells does not require the destruction of an embryo. Research into adult stem cells has been fueled by their abilities to divide or self-renew indefinitely and generate all the cell types of the organ from which they originate - potentially regenerating the entire organ from a few cells. Also known as somatic (from Greek Σωματικóς, of the body) stem cells, they can be found in children, as well as adults. A - stem cells are red B - progenitor cell C - differentiated cell 1 - symmetric stem cell division 2 - asymmetric stem cell division 3 - progenitor division 4 - terminal differentiationĪdult stem cells are undifferentiated cells found throughout the body that divide to replenish dying cells and regenerate damaged tissues.
0 kommentar(er)
