A high-content drug screening strategy to identify protein level modulators for genetic diseases: a proof-of-principle in Autosomal Dominant LeukoDystrophy (ADLD)

In genetic diseases, the most prevalent mechanism of pathogenicity is an altered expression of dosage-sensitive genes. Drugs that restore physiological levels of these genes should be effective in treating the associated conditions. We developed a screening strategy, based on a bicistronic dual-reporter vector, for identifying compounds that modulate proteins levels, and used it in a pharmacological screening approach. To provide a proof-of-principle, we chose Autosomal Dominant LeukoDystrophy (ADLD), an ultra-rare adult-onset neurodegenerative disorder caused by lamin B1 (LMNB1) overexpression. We used a stable CHO cell line simultaneously expresses an AcGFP reporter fused to LMNB1 and a Ds-Red normalizer. Using high-content imaging analysis, we screened a library of 717 biologically active compounds and approved drugs, and identified alvespimycin, an HSP90 inhibitor, as a positive hit. We confirmed that alvespimycin can reduce LMNB1 levels by 30-80% in five different cell lines (fibroblasts, NIH3T3, CHO, COS-7 and rat primary glial cells). In ADLD fibroblasts, alvespimycin reduced cytoplasmic LMNB1 by about 50%. We propose this approach for effectively identifying potential drugs for treating genetic diseases associated with deletions/duplications, and paving the way towards phase II clinical trials. This article is protected by copyright. All rights reserved.