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A novel small molecule target in human airway smooth muscle for potential treatment of obstructive lung diseases: a staged high-throughput biophysical screening

Steven S An1*, Peter S Askovich2, Thomas I Zarembinski2, Kwangmi Ahn3, John M Peltier2, Moritz von Rechenberg2, Sudhir Sahasrabudhe2 and Jeffrey J Fredberg4

  • * Corresponding author: Steven S An

  • † Equal contributors

Author Affiliations

1 Division of Physiology, Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA

2 Prolexys Pharmaceuticals, Inc., Salt Lake City, UT 84116, USA

3 Division of Biostatistics, Department of Public Health Sciences, Penn State College of Medicine, Hershey, PA 17033, USA

4 Program in Molecular and Integrative Physiological Sciences, Harvard School of Public Health, Boston, MA 02115, USA

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Respiratory Research 2011, 12:8  doi:10.1186/1465-9921-12-8

Published: 13 January 2011



A newly identified mechanism of smooth muscle relaxation is the interaction between the small heat shock protein 20 (HSP20) and 14-3-3 proteins. Focusing upon this class of interactions, we describe here a novel drug target screening approach for treating airflow obstruction in asthma.


Using a high-throughput fluorescence polarization (FP) assay, we screened a library of compounds that could act as small molecule modulators of HSP20 signals. We then applied two quantitative, cell-based biophysical methods to assess the functional efficacy of these molecules and rank-ordered their abilities to relax isolated human airway smooth muscle (ASM). Scaling up to the level of an intact tissue, we confirmed in a concentration-responsive manner the potency of the cell-based hit compounds.


Among 58,019 compound tested, 268 compounds caused 20% or more reduction of the polarized emission in the FP assay. A small subset of these primary screen hits, belonging to two scaffolds, caused relaxation of isolated ASM cell in vitro and attenuated active force development of intact tissue ex vivo.


This staged biophysical screening paradigm provides proof-of-principle for high-throughput and cost-effective discovery of new small molecule therapeutic agents for obstructive lung diseases.