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Kang SG, Kim C, Aiken J, Yoo HS, McKenzie D. Dual MicroRNA to Cellular Prion Protein Inhibits Propagation of Pathogenic Prion Protein in Cultured Cells. Mol Neurobiol 2017; 55:2384-2396. [PMID: 28357807 DOI: 10.1007/s12035-017-0495-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 03/14/2017] [Indexed: 01/08/2023]
Abstract
Prion diseases are fatal transmissible neurodegenerative disorders affecting humans and various mammals. In spite of intensive efforts, there is no effective cure or treatment for prion diseases. Cellular forms of prion protein (PrPC) is essential for propagation of abnormal isoforms of prion protein (PrPSc) and pathogenesis. The effect of an artificial dual microRNA (DmiR) on PrPC suppression and resultant inhibition of prion replication was determined using prion-infectible cell cultures: differentiated C2C12 culture and primary mixed neuronal and glial cells culture (MNGC). Processing of DmiR by prion-susceptible myotubes, but not by reserve cells, in differentiated C2C12 culture slowed prion replication, implying an importance of cell type-specific PrPC targeting. In MNGC, reduction of PrPC with DmiR was effective for suppressing prion replication. MNGC lentivirally transduced with non-targeting control miRNAs (scrambled) reduced prion replication at a level similar to that with a synthetic analogue of viral RNA, poly I:C. The results suggest that a synergistic combination of the immunostimulatory RNA duplexes (miRNA) and PrPC silencing with DmiR might augment a therapeutic potential of RNA interference.
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Affiliation(s)
- Sang-Gyun Kang
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB, Canada.,Department of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton, AB, Canada
| | - Chiye Kim
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB, Canada.,Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Judd Aiken
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB, Canada.,Department of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton, AB, Canada
| | - Han Sang Yoo
- Department of Infectious Diseases, College of Veterinary Medicine, BK21 PLUS, Seoul National University, Seoul, 08826, Republic of Korea.
| | - Debbie McKenzie
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB, Canada. .,Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada.
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Silber BM, Gever JR, Rao S, Li Z, Renslo AR, Widjaja K, Wong C, Giles K, Freyman Y, Elepano M, Irwin JJ, Jacobson MP, Prusiner SB. Novel compounds lowering the cellular isoform of the human prion protein in cultured human cells. Bioorg Med Chem 2014; 22:1960-72. [PMID: 24530226 DOI: 10.1016/j.bmc.2014.01.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 12/23/2013] [Accepted: 01/01/2014] [Indexed: 11/20/2022]
Abstract
PURPOSE Previous studies showed that lowering PrP(C) concomitantly reduced PrP(Sc) in the brains of mice inoculated with prions. We aimed to develop assays that measure PrP(C) on the surface of human T98G glioblastoma and IMR32 neuroblastoma cells. Using these assays, we sought to identify chemical hits, confirmed hits, and scaffolds that potently lowered PrP(C) levels in human brains cells, without lethality, and that could achieve drug concentrations in the brain after oral or intraperitoneal dosing in mice. METHODS We utilized HTS ELISA assays to identify small molecules that lower PrP(C) levels by ≥30% on the cell surface of human glioblastoma (T98G) and neuroblastoma (IMR32) cells. RESULTS From 44,578 diverse chemical compounds tested, 138 hits were identified by single point confirmation (SPC) representing 7 chemical scaffolds in T98G cells, and 114 SPC hits representing 6 scaffolds found in IMR32 cells. When the confirmed SPC hits were combined with structurally related analogs, >300 compounds (representing 6 distinct chemical scaffolds) were tested for dose-response (EC₅₀) in both cell lines, only studies in T98G cells identified compounds that reduced PrP(C) without killing the cells. EC₅₀ values from 32 hits ranged from 65 nM to 4.1 μM. Twenty-eight were evaluated in vivo in pharmacokinetic studies after a single 10 mg/kg oral or intraperitoneal dose in mice. Our results showed brain concentrations as high as 16.2 μM, but only after intraperitoneal dosing. CONCLUSIONS Our studies identified leads for future studies to determine which compounds might lower PrP(C) levels in rodent brain, and provide the basis of a therapeutic for fatal disorders caused by PrP prions.
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Affiliation(s)
- B Michael Silber
- Institute for Neurodegenerative Diseases, University of California, San Francisco, United States; Department of Neurology, University of California, San Francisco, United States; Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, United States
| | - Joel R Gever
- Institute for Neurodegenerative Diseases, University of California, San Francisco, United States; Department of Neurology, University of California, San Francisco, United States
| | - Satish Rao
- Institute for Neurodegenerative Diseases, University of California, San Francisco, United States; Department of Neurology, University of California, San Francisco, United States
| | - Zhe Li
- Institute for Neurodegenerative Diseases, University of California, San Francisco, United States; Department of Neurology, University of California, San Francisco, United States
| | - Adam R Renslo
- Small Molecule Discovery Center, University of California, San Francisco, United States; Department of Pharmaceutical Chemistry, University of California, San Francisco, United States
| | - Kartika Widjaja
- Institute for Neurodegenerative Diseases, University of California, San Francisco, United States
| | - Casper Wong
- Institute for Neurodegenerative Diseases, University of California, San Francisco, United States
| | - Kurt Giles
- Institute for Neurodegenerative Diseases, University of California, San Francisco, United States; Department of Neurology, University of California, San Francisco, United States
| | - Yevgeniy Freyman
- Institute for Neurodegenerative Diseases, University of California, San Francisco, United States
| | - Manuel Elepano
- Institute for Neurodegenerative Diseases, University of California, San Francisco, United States
| | - John J Irwin
- Department of Pharmaceutical Chemistry, University of California, San Francisco, United States
| | - Matthew P Jacobson
- Institute for Neurodegenerative Diseases, University of California, San Francisco, United States; Department of Pharmaceutical Chemistry, University of California, San Francisco, United States
| | - Stanley B Prusiner
- Institute for Neurodegenerative Diseases, University of California, San Francisco, United States; Department of Neurology, University of California, San Francisco, United States.
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Mays CE, Ryou C. Plasminogen stimulates propagation of protease-resistant prion protein in vitro. FASEB J 2010; 24:5102-12. [PMID: 20732953 DOI: 10.1096/fj.10-163600] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
To clarify the role of plasminogen as a cofactor for prion propagation, we conducted functional assays using a cell-free prion protein (PrP) conversion assay termed protein misfolding cyclic amplification (PMCA) and prion-infected cell lines. Here, we report that plasminogen stimulates propagation of the protease-resistant scrapie PrP (PrP(Sc)). Compared to control PMCA conducted without plasminogen, addition of plasminogen in PMCA using wild-type brain material significantly increased PrP conversion, with an EC(50) = ∼56 nM. PrP conversion in PMCA was substantially less efficient with plasminogen-deficient brain material than with wild-type material. The activity stimulating PrP conversion was specific for plasminogen and conserved in its kringle domains. Such activity was abrogated by modification of plasminogen structure and interference of PrP-plasminogen interaction. Kinetic analysis of PrP(Sc) generation demonstrated that the presence of plasminogen in PMCA enhanced the PrP(Sc) production rate to ∼0.97 U/μl/h and reduced turnover time to ∼1 h compared to those (∼0.4 U/μl/h and ∼2.5 h) obtained without supplementation. Furthermore, as observed in PMCA, plasminogen and kringles promoted PrP(Sc) propagation in ScN2a and Elk 21(+) cells. Our results demonstrate that plasminogen functions in stimulating conversion processes and represents the first cellular protein cofactor that enhances the hypothetical mechanism of prion propagation.
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Affiliation(s)
- Charles E Mays
- Sanders-Brown Center on Aging and Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA
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Pulford B, Reim N, Bell A, Veatch J, Forster G, Bender H, Meyerett C, Hafeman S, Michel B, Johnson T, Wyckoff AC, Miele G, Julius C, Kranich J, Schenkel A, Dow S, Zabel MD. Liposome-siRNA-peptide complexes cross the blood-brain barrier and significantly decrease PrP on neuronal cells and PrP in infected cell cultures. PLoS One 2010; 5:e11085. [PMID: 20559428 PMCID: PMC2885418 DOI: 10.1371/journal.pone.0011085] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 05/20/2010] [Indexed: 01/23/2023] Open
Abstract
Background Recent advances toward an effective therapy for prion diseases employ RNA interference to suppress PrPC expression and subsequent prion neuropathology, exploiting the phenomenon that disease severity and progression correlate with host PrPC expression levels. However, delivery of lentivirus encoding PrP shRNA has demonstrated only modest efficacy in vivo. Methodology/Principal Findings Here we describe a new siRNA delivery system incorporating a small peptide that binds siRNA and acetylcholine receptors (AchRs), acting as a molecular messenger for delivery to neurons, and cationic liposomes that protect siRNA-peptide complexes from serum degradation. Conclusions/Significance Liposome-siRNA-peptide complexes (LSPCs) delivered PrP siRNA specifically to AchR-expressing cells, suppressed PrPC expression and eliminated PrPRES formation in vitro. LSPCs injected intravenously into mice resisted serum degradation and delivered PrP siRNA throughout the brain to AchR and PrPC-expressing neurons. These data promote LSPCs as effective vehicles for delivery of PrP and other siRNAs specifically to neurons to treat prion and other neuropathological diseases.
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Affiliation(s)
- Bruce Pulford
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Natalia Reim
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Aimee Bell
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Jessica Veatch
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Genevieve Forster
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Heather Bender
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Crystal Meyerett
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Scott Hafeman
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Brady Michel
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Theodore Johnson
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - A. Christy Wyckoff
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Gino Miele
- Pfizer Global Research & Development, Translational Medicine Research Collaboration, Dundee, Scotland
| | - Christian Julius
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Jan Kranich
- Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Alan Schenkel
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Steven Dow
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Mark D. Zabel
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
- * E-mail:
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