Spinal muscular atrophy (SMA) is an autosomal recessive disorder characterized by progressive muscle weakness due to deterioration of motor neurons. SMA results from homozygous mutation of the SMN (survival motor neuron) 1 gene. A nearly identical copy, SMN2, fails to protect from development of SMA as its major mRNA undergoes alternative splicing that encodes for an unstable SMN protein. This alternative spliced product excludes exon 7. A small fraction of the SMN2 transcripts include exon 7 and encode the same SMN protein as does SMN1. ? ? This application describes a two-year hit-to-lead discovery program to identify drug-like compounds that increase intracellular SMN protein levels. Using a redesigned, improved, and validated cell-based reporter assay, the investigators identified activators of SMN protein expression from a library of 115,000 diverse chemical entities.
Specific Aim 1 of this project is to evaluate the biological activity of these hits in SMA cell culture models and determine the mechanism of action for each compound.
Specific Aim 2 will then strives to define structure activity relationships (SAR) for lead optimization, and test available structural analogues or synthesize a small focused library of related compounds to increase activity and drug-like characteristics of the lead compounds. ? ? Importantly, the application merges the experience and capabilities of the laboratories investigating the molecular biology of SMA with the expertise of a Center devoted to the development of novel therapies for neurodegenerative diseases that reproduces a drug company approach to identify pharmacologically active compounds. The predicted outcome of this application is the identification and characterization of chemically suitable compounds with nanomolar activities in cell-based assays that can be entered into a preclinical program in SMA mouse models. The ultimate goal is to develop an effective drug for treatment of spinal muscular atrophy, the leading genetic cause of infant mortality. ? ? ?

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21HD057402-01
Application #
7361787
Study Section
Special Emphasis Panel (ZHD1-MRG-C (02))
Program Officer
Zajicek, Anne
Project Start
2008-02-01
Project End
2010-01-31
Budget Start
2008-02-01
Budget End
2009-01-31
Support Year
1
Fiscal Year
2008
Total Cost
$225,000
Indirect Cost
Name
University of Massachusetts Medical School Worcester
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
603847393
City
Worcester
State
MA
Country
United States
Zip Code
01655
Rietz, Anne; Li, Hongxia; Quist, Kevin M et al. (2017) Discovery of a Small Molecule Probe That Post-Translationally Stabilizes the Survival Motor Neuron Protein for the Treatment of Spinal Muscular Atrophy. J Med Chem 60:4594-4610
Choi, Sungwoon; Calder, Alyssa N; Miller, Eliza H et al. (2017) Optimization of a series of heterocycles as survival motor neuron gene transcription enhancers. Bioorg Med Chem Lett 27:5144-5148
Calder, Alyssa N; Androphy, Elliot J; Hodgetts, Kevin J (2016) Small Molecules in Development for the Treatment of Spinal Muscular Atrophy. J Med Chem 59:10067-10083
Cherry, Jonathan J; Osman, Erkan Y; Evans, Matthew C et al. (2013) Enhancement of SMN protein levels in a mouse model of spinal muscular atrophy using novel drug-like compounds. EMBO Mol Med 5:1103-18
Cherry, Jonathan J; Evans, Matthew C; Ni, Jake et al. (2012) Identification of novel compounds that increase SMN protein levels using an improved SMN2 reporter cell assay. J Biomol Screen 17:481-95