Identification of histone deacetylase inhibitors for reversing gene expression profiles in Huntington's disease striatal cells
Final Report Abstract
Huntington’s disease (HD) is the most prevalent autosomal inherited neurodegenerative disorder, which is characterized by progressive motor dysfunction, cognitive deterioration and psychiatric disturbances. To date, there are no human HD neuronal cell models available for drug screening. For this reason we aimed to generate neurons from human induced pluripotent stem (iPS) cells originally derived from patient specific fibroblasts which will serve as a human neuronal model for Huntington’s disease. Using this neuronal model, a list of compounds with distinct specificities for different HDACs were to be tested as potential therapeutics for HD. The compounds comprise a novel class of HDAC inhibitors (pimelic diphenylamides), which do not exhibit the toxicity profiles reported for other HDAC inhibitors. This class of inhibitors was previously identified in our laboratory and studies indicate that at least one member of these molecules shows clinical efficacy in a mouse model for HD. Because of several obstacles, the study could not be finished in the given time frame. Instead of using the commercially available iPS cells from the Harvard Stem Cell Institute, it was necessary to generate and fully characterize HD iPS cells derived from patient specific fibroblasts. HD fibroblasts were successfully reprogrammed and the established HD iPS cells were characterized by realtime- PCR, immunocytochemistry, microarray, teratoma assay and karyotyping. No changes in repeat lengths did occur during reprogramming and further passaging of HD iPS cells. The HD iPS cells could be differentiated into a high population of TUJ1 and MAP2 positive cells as shown by immunocytochemistry and FACS. Due to a high variability in the differentiating process and the characteristic of the HD iPS clone it was not possible to generate a high enough population of neuronal cells for the drug screening assays thus far.
