TY - JOUR
T1 - Antiprion activity of DB772 and related monothiophene- and furan-based analogs in a persistently infected ovine microglia culture system
AU - Dinkel, Kelcey D.
AU - Stanton, James B.
AU - Boykin, David W.
AU - Stephens, Chad E.
AU - Madsen-Bouterse, Sally A.
AU - Schneider, David A.
N1 - Funding Information:
We thank the following people for providing excellent technical support to this project: Juan Muñoz-Gutiérrez, Edith Orozco, Bruce Mathison, and Nancy Kumpula. Kelcey D. Dinkel received support for this project from the National Institute of General Medical Sciences of the National Institutes of Health under award number T32GM008336. This study was also supported by the USDA Agricultural Research Service under CRIS 2090-32000-030-00. This work, including the efforts of Kelcey D. Dinkel, was funded by HHS | National Institutes of Health (NIH) (Biotechnology Training Grant). This work, including the efforts of David A. Schneider, was funded by U.S. Department of Agriculture (USDA) (CRIS 5348-32000-030-00D). This work, including the efforts of James B. Stanton, was funded by University of Georgia Office of the Vice President for Research. This work, including the efforts of James B. Stanton, was funded by USDA Animal Health Formula Funds (1007561 and 1000444).
Publisher Copyright:
Copyright © 2016 Dinkel et al.
PY - 2016/9/1
Y1 - 2016/9/1
N2 - The transmissible spongiform encephalopathies are fatal neurodegenerative disorders characterized by the misfolding of the native cellular prion protein (PrPC) into the accumulating, disease-associated isoform (PrPSc). Despite extensive research into the inhibition of prion accumulation, no effective treatment exists. Previously, we demonstrated the inhibitory activity of DB772, a monocationic phenyl-furan-benzimidazole, against PrPSc accumulation in sheep microglial cells. In an effort to determine the effect of structural substitutions on the antiprion activity of DB772, we employed an in vitro strategy to survey a library of structurally related, monothiophene- and furan-based compounds for improved inhibitory activity. Eighty-nine compounds were screened at 1 μM for effects on cell viability and prion accumulation in a persistently infected ovine microglia culture system. Eleven compounds with activity equivalent to or higher than that of DB772 were identified as preliminary hit compounds. For the preliminary hits, cytotoxicities and antiprion activities were compared to calculate the tissue culture selectivity index. A structure-activity relationship (SAR) analysis was performed to determine molecular components contributing to antiprion activity. To investigate potential mechanisms of inhibition, effects on PrPC and PrPSc were examined. While inhibition of total PrPC was not observed, the results suggest that a potential target for inhibition at biologically relevant concentrations is through PrPC misfolding to PrPSc. Further, SAR analysis suggests that two structural elements were associated with micromolar antiprion activity. Taken together, the described data provide a foundation for deeper investigation into untested DB compounds and in the design of effective therapeutics.
AB - The transmissible spongiform encephalopathies are fatal neurodegenerative disorders characterized by the misfolding of the native cellular prion protein (PrPC) into the accumulating, disease-associated isoform (PrPSc). Despite extensive research into the inhibition of prion accumulation, no effective treatment exists. Previously, we demonstrated the inhibitory activity of DB772, a monocationic phenyl-furan-benzimidazole, against PrPSc accumulation in sheep microglial cells. In an effort to determine the effect of structural substitutions on the antiprion activity of DB772, we employed an in vitro strategy to survey a library of structurally related, monothiophene- and furan-based compounds for improved inhibitory activity. Eighty-nine compounds were screened at 1 μM for effects on cell viability and prion accumulation in a persistently infected ovine microglia culture system. Eleven compounds with activity equivalent to or higher than that of DB772 were identified as preliminary hit compounds. For the preliminary hits, cytotoxicities and antiprion activities were compared to calculate the tissue culture selectivity index. A structure-activity relationship (SAR) analysis was performed to determine molecular components contributing to antiprion activity. To investigate potential mechanisms of inhibition, effects on PrPC and PrPSc were examined. While inhibition of total PrPC was not observed, the results suggest that a potential target for inhibition at biologically relevant concentrations is through PrPC misfolding to PrPSc. Further, SAR analysis suggests that two structural elements were associated with micromolar antiprion activity. Taken together, the described data provide a foundation for deeper investigation into untested DB compounds and in the design of effective therapeutics.
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U2 - 10.1128/AAC.00811-16
DO - 10.1128/AAC.00811-16
M3 - Article
C2 - 27381401
AN - SCOPUS:84983667056
SN - 0066-4804
VL - 60
SP - 5467
EP - 5482
JO - Antimicrobial agents and chemotherapy
JF - Antimicrobial agents and chemotherapy
IS - 9
ER -