title: Discovery of 1,3,4-oxidiazole scaffold compounds as inhibitors of superoxide dismutase expression.
abstract: The treatment of neurodegenerative diseases is difficult because of multiple etiologies and the interplay of genetics and environment as precipitating factors. In the case of amyotrophic lateral sclerosis (ALS), we have knowledge of a handful of genes that cause disease when mutated. However, drugs to counteract the effect of genetic mutations have not yet been found. One of the causative genes, Cu, Zn-superoxide dismutase (SOD1) is responsible for about 10-15% of the genetically linked autosomal dominant disease. Our rationale was that compounds that reduce expression of the mutant protein would be beneficial to slow onset and/or disease progression. We screened candidate compounds using a cell-based in vitro assay for those that reduce mutant SOD1 (G93A) protein expression. This led to the discovery of 2-[3-iodophenyl)methylsulfanyl]-5pyridin-4-yl-1,3,4-oxadiazole, a known protein kinase inhibitor that decreases G93A-SOD1 expression in vitro and in the brain and spinal cord in vivo. However, this compound has a biphasic dose response curve and a likely toxophore which limit its therapeutic window for chronic disease such as ALS. Therefore, we designed and tested a focused library of analogs for their ability to decrease SOD1 expression in vitro. This exercise resulted in the identification of a lead compound with improved drug-like characteristics and activity. Development of small molecules that reduce the expression of etiologically relevant toxic proteins is a strategy that may also be extended to familial ALS linked to gain of function mutations in other genes.
authors.affiliation: Department of Molecular Pharmacology & Biological Chemistry, Northwestern University, 303 E. Chicago Ave, Chicago, IL 60611, United States. Electronic address: t-lukas@northwestern.edu.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Lukas
authors.affiliation: The Center for Molecular Innovation and Drug Discovery, Silverman Hall, Evanston, IL 60208, United States. Electronic address: ges480@northwestern.edu.
authors.forename: Gary E
authors.initials: GE
authors.lastname: Schiltz
authors.affiliation: Department of Neurology, Northwestern University, Chicago, IL 60611, United States. Electronic address: harrat75@gmail.com.
authors.forename: Hasan
authors.initials: H
authors.lastname: Arrat
authors.affiliation: The Center for Molecular Innovation and Drug Discovery, Silverman Hall, Evanston, IL 60208, United States; Department of Chemistry, The Center for Molecular Innovation and Drug Discovery, Silverman Hall, Evanston, IL 60208, United States. Electronic address: Scheidt@northwestern.edu.
authors.forename: Karl
authors.initials: K
authors.lastname: Scheidt
authors.affiliation: Department of Neurology, Northwestern University, Chicago, IL 60611, United States. Electronic address: t-siddique@northwestern.edu.
authors.forename: Teepu
authors.initials: T
authors.lastname: Siddique
mesh_terms: D000818:Animals; D002460:Cell Line; D004353:Drug Evaluation, Preclinical; D005786:Gene Expression Regulation / Q000187:drug effects*; D051379:Mice; D010069:Oxadiazoles / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D054852:Small Molecule Libraries / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D013482:Superoxide Dismutase / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D010069:Oxadiazoles; D054852:Small Molecule Libraries; C583463:1,3,4-oxadiazole; D013482:Superoxide Dismutase
keywords: Amyotrophic lateral sclerosis; Chemical synthesis; Hit-to-lead; Inhibitor; Pharmacokinetics; Superoxide dismutase; Transgenic mouse