Prions are infectious proteins that cause age-dependent neurodegeneration in humans and animals. The accumulation of an alternatively folded isoform of the prion protein (PrPSc) in the brains of humans and animals is the hallmark of the prion disorders that include Creutzfeldt-Jakob disease (CJD). The prion diseases are invariably fatal and no effective treatment exists. In this application, we propose to continue our studies directed toward devising effective medications for the treatment of CJD. Toward this goal, we want to identify several compounds that either alone or in combination substantially prolong the incubation times in transgenic mice. A model for our proposed research is reflected in our earlier work with bigenic mouse expressing an inducible PrP transgene. These studies showed a substantial prolongation of the incubation time by doxycycline-mediated inhibition of PrPc expression. Toward achieving this goal, we plan to adapt human (Hu) prion protein (PrP) based assays to the High Throughput Screening (HTS) of chemical libraries. Initially, we plan to continue using prion-infected mouse (Mo) neuroblastoma cells designated ScN2a for HTS studies. At the same time, we propose to use uninfected, human (Hu) glioblastoma cells in our HTS search for compounds that decrease HuPrPc levels. In addition, we propose to create cultured cells that propagate either wt Hu or chimeric Hu/Mo CJD prions. These novel cell lines will be used for HTS of chemical libraries. In the proposed studies, both protease-sensitive (s) and resistant (r) PrPSc will be measured in both dividing and non-dividing cells. Potent, non-toxic lead compounds with anti-prion activity will be chemically and computationally optimized by appropriate Structure-Activity-Relationship (SAR) studies. Some computational analyses will focus on the permeability of lead compounds across the bloodbrain- barrier (BBB) and other computational studies on the formation of PrPSc as well as structural models of this protein. Because of problems that plague prion-infected cultured cell assays, we propose to develop additional assays for HTS that include adaptation of an amyloid seeding assay (ASA) using HuPrPSc to seed the polymerization of recombinant (rec) HuPrP as well as a humanized version of a fluorescence polarization (FP) assay that measures the binding of PrP peptides to HuPrPSc. We also propose to use transgenic (Tg) mice expressing either a chimeric Hu/Mo PrP or wt HuPrP that are susceptible to Hu CJD prions. One line of Tg mice exhibits incubation times of ~80 days and these animals should greatly facilitate our studies.

Public Health Relevance

The ultimate goal of these studies is to develop drugs that cure human prion disorders including CJD. The successful development of a therapeutic for CJD would have important implications for creating meaningful treatments for other age-dependent neurodegenerative diseases that include Alzheimer's disease.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Program Projects (P01)
Project #
5P01AG021601-10
Application #
8433348
Study Section
Special Emphasis Panel (ZAG1-ZIJ-7 (J1))
Program Officer
Mackiewicz, Miroslaw
Project Start
2003-06-01
Project End
2014-02-28
Budget Start
2013-04-15
Budget End
2014-02-28
Support Year
10
Fiscal Year
2013
Total Cost
$1,783,370
Indirect Cost
$629,085
Name
University of California San Francisco
Department
Neurology
Type
Schools of Medicine
DUNS #
094878337
City
San Francisco
State
CA
Country
United States
Zip Code
94143
Lexa, Katrina W; Dolghih, Elena; Jacobson, Matthew P (2014) A structure-based model for predicting serum albumin binding. PLoS One 9:e93323
Silber, B Michael; Gever, Joel R; Rao, Satish et al. (2014) Novel compounds lowering the cellular isoform of the human prion protein in cultured human cells. Bioorg Med Chem 22:1960-72
Bettcher, B M; Gelfand, J M; Irani, S R et al. (2014) More than memory impairment in voltage-gated potassium channel complex encephalopathy. Eur J Neurol 21:1301-10
Stöhr, Jan; Condello, Carlo; Watts, Joel C et al. (2014) Distinct synthetic A? prion strains producing different amyloid deposits in bigenic mice. Proc Natl Acad Sci U S A 111:10329-34
Minikel, Eric Vallabh; Zerr, Inga; Collins, Steven J et al. (2014) Ascertainment bias causes false signal of anticipation in genetic prion disease. Am J Hum Genet 95:371-82
Irani, Sarosh R; Gelfand, Jeffrey M; Bettcher, Brianne M et al. (2014) Effect of rituximab in patients with leucine-rich, glioma-inactivated 1 antibody-associated encephalopathy. JAMA Neurol 71:896-900
Watts, Joel C; Giles, Kurt; Patel, Smita et al. (2014) Evidence that bank vole PrP is a universal acceptor for prions. PLoS Pathog 10:e1003990
Watts, Joel C; Prusiner, Stanley B (2014) Mouse models for studying the formation and propagation of prions. J Biol Chem 289:19841-9
Watts, Joel C; Condello, Carlo; Stöhr, Jan et al. (2014) Serial propagation of distinct strains of A? prions from Alzheimer's disease patients. Proc Natl Acad Sci U S A 111:10323-8
Li, Zhe; Gever, Joel; Rao, Satish et al. (2013) Discovery and Preliminary SAR of Arylpiperazines as Novel, Brainpenetrant Antiprion Compounds. ACS Med Chem Lett 4:397-401

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