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Stem cells and stem cell
interventions
Figure l . Stem cells and regenerative medicine
Pluripotent ” 1/ “ewe stem cells \ e cells (e.g., embryonic Sfem Cells) / intestinal °’/55» Z, W cells red blood —> $0 Ce… # liver cells \ muscle X cells
Stem cell interventions Stem cell interventions are used to describe many different types of treatments that use stem cells or cells that come from stem cells. The goal is to use these cells in order to replace tissue that was damaged from injury or disease. How- ever as simple as this may sound, there are major obstacles to the successful use of these kinds of interventions, including the fact that the patient’s body may reject transplanted cells. As with organ transplantation, this generally requires patients to also take drugs that suppress their immune system. For this reason, scientists are excited about induced pluripotent stem cells because they can be created from the cells of the actual patient and, as a result, they may not be rejected after transplantation. Similarly, mesenchymal stem cells might also restrain the immune system and escape rejection (see Box 1).
Stem cells can be transplanted in different ways, for example, through a surgi- cal operation or through injection into the blood stream. The different trans- plantation procedures carry risks, including bleeding, infection, or tissue dam- age. In addition, the transplanted stem cells pose risks. They may form tumors or migrate away from the area they were transplanted to another place in the body and cause unknown side effects.
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The human body contains hundreds of different types of specialized cells such as those that make up muscle, fat, the nervous system, and skin. All of these specialized cells trace their origins back to stem cells. Stem cells can give rise to different types of cells through a process called differentiation. If scientists can turn stem cells into specific cells, they might be able to treat different diseases and injuries by transplanting them into patients — this is a form of regenerative medicine (see Figure I ). For example, if heart muscle is damaged after a heart attack, stem cells might be used to make new heart muscle to be transplanted into the heart to repair it. There are many types of stem cells and they all have unique biological properties (see Box I ).
Stem cells can differentiate into many cell types. Specific cells derived from stem cells can be transplanted into a patient to treat a disease or injury, such as Parkison’s disease, spinal cord injury, Alzheimer’s disease, heart disease, diabetes, and others.
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