title: Antiprion compounds that reduce PrP(Sc) levels in dividing and stationary-phase cells.
abstract: During prion diseases, a normally benign, host protein, denoted PrP(C), undergoes alternative folding into the aberrant isoform, PrP(Sc). We used ELISA to identify and confirm hits in order to develop leads that reduce PrP(Sc) in prion-infected dividing and stationary-phase mouse neuroblastoma (ScN2a-cl3) cells. We tested 52,830 diverse small molecules in dividing cells and 49,430 in stationary-phase cells. This led to 3100 HTS and 970 single point confirmed (SPC) hits in dividing cells, 331 HTS and 55 confirmed SPC hits in stationary-phase cells as well as 36 confirmed SPC hits active in both. Fourteen chemical leads were identified from confirmed SPC hits in dividing cells and three in stationary-phase cells. From more than 682 compounds tested in concentration-effect relationships in dividing cells to determine potency (EC50), 102 had EC50 values between 1 and 10 μM and 50 had EC50 values of <1 μM; none affected cell viability. We observed an excellent correlation between EC50 values determined by ELISA and Western immunoblotting for 28 representative compounds in dividing cells (R(2)=0.75; p <0.0001). Of the 55 confirmed SPC hits in stationary-phase cells, 23 were piperazine, indole, or urea leads. The EC50 values of one indole in stationary-phase and dividing ScN2a-cl3 cells were 7.5 and 1.6 μM, respectively. Unexpectedly, the number of hits in stationary-phase cells was ~10% of that in dividing cells. The explanation for this difference remains to be determined.
authors.affiliation: Institute for Neurodegenerative Diseases, University of California, San Francisco, CA 94143, United States; Department of Neurology, University of California, San Francisco, CA 94143, United States; Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143, United States.
authors.forename: B Michael
authors.initials: BM
authors.lastname: Silber
authors.forename: Joel R
authors.initials: JR
authors.lastname: Gever
authors.forename: Zhe
authors.initials: Z
authors.lastname: Li
authors.forename: Alejandra
authors.initials: A
authors.lastname: Gallardo-Godoy
authors.forename: Adam R
authors.initials: AR
authors.lastname: Renslo
authors.forename: Kartika
authors.initials: K
authors.lastname: Widjaja
authors.forename: John J
authors.initials: JJ
authors.lastname: Irwin
authors.forename: Satish
authors.initials: S
authors.lastname: Rao
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Jacobson
authors.forename: Sina
authors.initials: S
authors.lastname: Ghaemmaghami
authors.forename: Stanley B
authors.initials: SB
authors.lastname: Prusiner
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D051379:Mice; D015394:Molecular Structure; D018620:PrPSc Proteins / Q000378:metabolism*; D054852:Small Molecule Libraries / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D018620:PrPSc Proteins; D054852:Small Molecule Libraries
keywords: Antiprion compounds; Dividing and stationary-phase brain cells; PrP(Sc)