A high-content screen identifies novel compounds that inhibit stress-induced TDP-43 cellular aggregation and associated cytotoxicity

• Published in: Journal of biomolecular screening Vol. 19; no. 1; pp. 44 - 56
• Main Authors: Boyd, Justin D, Lee, Peter, Feiler, Marisa S, Zauur, Nava, Liu, Min, Concannon, John, Ebata, Atsushi, Wolozin, Benjamin, Glicksman, Marcie A
• Format: Journal Article
• Language: English
• Published: United States 01.01.2014
• Subjects: Animals; Animals, Genetically Modified; Arsenites - pharmacology; Caenorhabditis elegans; Cell Line; DNA-Binding Proteins - antagonists & inhibitors; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Drug Discovery - methods; Drug Evaluation, Preclinical - methods; Gene Expression; Genes, Reporter; High-Throughput Screening Assays; Humans; Neurodegenerative Diseases - drug therapy; Neurodegenerative Diseases - genetics; Neurodegenerative Diseases - metabolism; Neuroprotective Agents - pharmacology; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Small Molecule Libraries; Sodium Compounds - pharmacology; Stress, Physiological - drug effects; high-throughput screen; protein synthesis; aggregation; amyotrophic lateral sclerosis; RNA binding protein; RNA granule
• DOI: 10.1177/1087057113501553
• ISSN: 2472-5552

TDP-43 is an RNA binding protein found to accumulate in the cytoplasm of brain and spinal cord from patients affected with amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Nuclear TDP-43 protein regulates transcription through several mechanisms, and under stressed conditions, it forms cytoplasmic aggregates that co-localize with stress granule (SG) proteins in cell culture. These granules are also found in the brain and spinal cord of patients affected with ALS and FTLD. The mechanism through which TDP-43 might contribute to neurodegenerative diseases is poorly understood. To investigate the pathophysiology of TDP-43 aggregation and to isolate potential therapeutic targets, we screened a chemical library of 75,000 compounds using high-content analysis with PC12 cells that inducibly express human TDP-43 tagged with green fluorescent protein (GFP). The screen identified 16 compounds that dose-dependently decreased the TDP-43 inclusions without significant cellular toxicity or changes in total TDP-43 expression levels. To validate the effect, we tested compounds by Western blot analysis and in a Caenorhabditis elegans model that replicates some of the relevant disease phenotypes. The hits from this assay will be useful for elucidating regulation of TDP-43, stress granule response, and possible ALS therapeutics.