chapter  5
26 Pages

Chapter High-Throughput and High-Content Screening for Huntington’s Disease Therapeutics

Since the isolation of the gene and mutation that cause Huntington’s disease (HD) more than a decade ago, there has been optimism that this knowledge would lead to

Introduction ............................................................................................................ 121 High-Throughput Screening .................................................................................. 123

High-Throughput and High-Content Screening ........................................... 123 Chemical Compound Libraries ....................................................................124 Compound Filtering and Library Assembly ................................................. 125 Assembly of Compound Libraries ................................................................ 126

Assay Development ............................................................................................... 126 HTS Assays in HD and Related Polyglutamine Disorders .................................... 128

Aggregation-Based Assays ........................................................................... 130 In Vitro Aggregation Assays ............................................................. 130

Cell-Based Aggregation Assays .................................................................... 131 Fluorescence Resonance Energy Transfer-Based Aggregation Assays ........ 131 Cell Death-Related Assays ........................................................................... 133 Caspase Inhibition-Based Assays ................................................................. 133 PC12 Cell-Based Viability Assays ................................................................ 134 ST14A Cell Viability Assays ........................................................................ 135

High-Content Screening Approaches toward HD .................................................. 136 HTS Achievements ................................................................................................ 138 Challenges in Prioritizing Hit Compounds ............................................................ 139 Small Molecules as Chemical Tools for Understanding HD Mechanisms ............ 141 Future Directions ................................................................................................... 141 References .............................................................................................................. 142

the rapid discovery of therapeutic agents for this fatal and incurable disease [1]. In fact, considerable effort has been invested in HD drug discovery, predominantly in academic environments but also in the biopharmaceutical industry to some certain extent. Historically, however, interest in HD research and development in large pharmaceutical rms has been limited by the relatively small size of the HD patient population (~30,000 affected persons in United States), which has led to the perception that the market size for HD might be too small to justify the investment of substantial resources necessary to bring a new drug to clinical trials. However, there is a growing appreciation for the actual market size of “ rst in class” drugs for otherwise unaddressable diseases, as well as for the idea that HD may prove to be a paradigmatic disease for other, much more prevalent neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease [2].