Suppressing glycogen storage with small molecule inhibitors as a therapeutic approach to Lafora disease Lafora disease is a fatal childhood-onset, progressive epilepsy caused by mutations at either the EPM2A or EPM2B genes and for which no cure is currently available. Much has been learned of the disease in the last decade that can help guide new approaches to effective therapies. A consistent feature is the accumulation of insoluble deposits, called Lafora bodies, in many tissues and, of special significance, in neurons in the brain. Lafora bodies contain polyglucosan, an abnormal glycogen-like compound that is less branched and less soluble than normal glycogen. In mouse models of Lafora disease, laforin-/- and malin-/- mice, genetic depletion or elimination of glycogen was shown to decrease the formation of Lafora bodies and to alleviate indicators of the disease. Therefore, current thinking is that the formation of Lafora bodies is causative of the disease and suppression of their formation would represent a promising approach as a therapy. In this project, we propose to reduce glycogen stores in the brain by developing small molecule inhibitors of its accumulation.
Aim 1 : Identification and validation of small molecule glycogen synthase inhibitors. We are searching for active site and allosteric site inhibitors of glycogen synthase by high-throughput screens (HTS) using novel assays. Positives from the above screens will be validated in vitro and analyzed by the Medicinal Chemistry Core for favorable ADME their potential to cross the blood brain barrier (BBB).
Aim 2. Medicinal chemistry optimization. Prioritized hits from Aim 1 will be further validated for activity through direct synthesis and a limited set of related analogs will either be purchased or synthesized to evaluate a range of sub-structures, substituents, and/or substitution patterns for activity by the in vitro analyses described in Aim 1. Preliminary structure-activity relationships (SAR) will inform on the potential for further pre-clinical development.
Aim 3 : Cell-based assay of glycogen accumulation, toxicity and preliminary pharmacokinetics. We have developed two novel plate-based assays to monitor cellular glycogen levels in glycogen accumulating cell lines. The assays will be applied to evaluate and validate glycogen synthase inhibitors identified in Aim 1 and could also be developed as an alternative for HTS of compound libraries to identify novel inhibitors at the cellular level. The most promising candidates will be advanced for toxicology and pharmacokinetic analyses in mice.
Aim 4 : Testing inhibitors of glycogen accumulation in mouse models of Lafora disease. Compounds identified in previous Aims that show most promise will be tested in laforin-/- and malin-/- mice to assess their effects on Lafora body formation, neurodegeneration and behavioral impairment associated with the disease. Any compounds making it to this stage will be candidates for further development via NINDS drug development programs of the IGNITE/BLUEPRINT initiatives, such as PAR-15-071.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Program Projects (P01)
Project #
5P01NS097197-02
Application #
9309109
Study Section
National Institute of Neurological Disorders and Stroke Initial Review Group (NSD)
Project Start
Project End
Budget Start
2017-07-01
Budget End
2018-06-30
Support Year
2
Fiscal Year
2017
Total Cost
Indirect Cost
Name
University of Kentucky
Department
Type
DUNS #
939017877
City
Lexington
State
KY
Country
United States
Zip Code
40526
Ahonen, Saija; Seath, Ian; Rusbridge, Clare et al. (2018) Nationwide genetic testing towards eliminating Lafora disease from Miniature Wirehaired Dachshunds in the United Kingdom. Canine Genet Epidemiol 5:2
Gentry, Matthew S; Guinovart, Joan J; Minassian, Berge A et al. (2018) Lafora disease offers a unique window into neuronal glycogen metabolism. J Biol Chem 293:7117-7125
Augé, Elisabet; Pelegrí, Carme; Manich, Gemma et al. (2018) Astrocytes and neurons produce distinct types of polyglucosan bodies in Lafora disease. Glia 66:2094-2107
Sanz, Pascual; Viana, Rosa; Garcia-Gimeno, Maria Adelaida (2018) AMPK Protein Interaction Analyses by Yeast Two-Hybrid. Methods Mol Biol 1732:143-157
Rubio-Villena, Carla; Viana, Rosa; Bonet, Jose et al. (2018) Astrocytes: new players in progressive myoclonus epilepsy of Lafora type. Hum Mol Genet 27:1290-1300
Brewer, M Kathryn; Gentry, Matthew S (2018) The 3rd International Lafora Epilepsy Workshop: Evidence for a cure. Epilepsy Behav 81:125-127
Sánchez, Marina P; García-Cabrero, Ana M; Sánchez-Elexpuru, Gentzane et al. (2018) Tau-Induced Pathology in Epilepsy and Dementia: Notions from Patients and Animal Models. Int J Mol Sci 19:
Kuchtová, Andrea; Gentry, Matthew S; Jane?ek, Štefan (2018) The unique evolution of the carbohydrate-binding module CBM20 in laforin. FEBS Lett 592:586-598
García-Gimeno, Maria Adelaida; Knecht, Erwin; Sanz, Pascual (2018) Lafora Disease: A Ubiquitination-Related Pathology. Cells 7:
Nitschke, Felix; Ahonen, Saija J; Nitschke, Silvia et al. (2018) Lafora disease - from pathogenesis to treatment strategies. Nat Rev Neurol 14:606-617

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