Scientists who study Alzheimer’s disease use animal models of aging and disease in many ways, from identifying mechanisms of disease to rapidly testing new drugs. However, animal models have certain drawbacks. Due in part to differences in anatomy, biochemistry, genetics, and physiology, the disease may manifest slightly differently in animals and humans, and the effects of pharmacological treatments may differ between human and animal cells.
Some limitations of animal models potentially could be overcome by developing human cell models of aging and disease. Scientists have found that human adult fibroblasts (skin cells) and other cell types can be “reprogrammed” into induced pluripotent stem (iPS) cells, which have the capacity to differentiate into any other type of cell. iPS cells offer enormous potential for generating age-specific and disease-specific cells for analyses of aging and disease mechanisms in human cells. In the near term, human iPS cells could be used for disease modeling to provide insight into disease mechanisms and as platforms for drug screening and testing. Eventually, iPS cells may be used for cell and tissue replacement therapies.
In 2011, NIH issued an FOA soliciting research applications on the development of human iPS cells and other reprogrammed cells for aging and Alzheimer’s disease modeling. Findings from these studies could energize the field by providing an inexpensive, renewable, and more precise model for discovery and testing of interventions. For more information, see http://grants.nih.gov/grants/guide/rfa-files/RFA-AG-12-008.html .