43.6: iPS Cell Differentiation
The ability of induced pluripotent stem cells or iPSCs to differentiate into most body cell types has stimulated repair and regenerative medicine research over the past few decades. iPSC-derived blood cells, hepatocytes, beta islet cells, cardiomyocytes, neurons, and other cell types can repair injuries or regenerate damaged tissue in diseases such as diabetes and neurodegenerative disorders.
iPSCs have been successfully used to treat age-related macular degeneration (AMD), a form of blindness. This disorder is caused by the loss of retinal pigment epithelium (RPE) due to aging. Skin cells from an AMD patient were isolated and reprogrammed to form iPSCs, which were then differentiated into RPE cells. When these newly formed RPE cells were transplanted into the patient's retina, they restored the patient's vision.
iPSCs have shown potential for treating sickle cell anemia using a patient's own cells. Researchers reprogrammed the bone marrow stromal cells of a sickle cell anemia patient to form iPSCs. The mutation that causes the sickle cell phenotype in iPSCs was corrected using the CRISPR-Cas system. These iPSCs, when differentiated into erythroid cells, expressed the normal β-globin protein.
iPSC-derived cells are also being explored for their potential in cancer therapy. Tissues destroyed in a cancer patient due to radiation or chemotherapy can be replaced using cells differentiated from the patient's cells. However, attempts to transplant such iPSC-derived cells have not to date been successful.