1
|
Otaki H, Taguchi Y, Nishida N. Conformation-Dependent Influences of Hydrophobic Amino Acids in Two In-Register Parallel β-Sheet Amyloids, an α-Synuclein Amyloid and a Local Structural Model of PrP Sc. ACS OMEGA 2022; 7:31271-31288. [PMID: 36092583 PMCID: PMC9453792 DOI: 10.1021/acsomega.2c03523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
Prions are unconventional pathogens that encode the pathogenic information in conformations of the constituent abnormal isoform of prion protein (PrPSc), independently of the nucleotide genome. Therefore, conformational diversity of PrPSc underlies the existence of many prion strains and species barriers of prions, although the conformational information is extremely limited. Interestingly, differences between polymorphic or species-specific residues responsible for the species/strain barriers are often caused by conservative replacements between hydrophobic amino acids. This implies that subtle differences among hydrophobic amino acids are significant for PrPSc structures. Here we analyzed the influence of different hydrophobic residues on the structures of an in-register parallel β-sheet amyloid of α-synuclein (αSyn) using molecular dynamics (MD) simulation and applied the knowledge from the αSyn amyloid to modeling a local structure of human PrPSc encompassing residues 107-143. We found that mutations equivalent to polymorphisms that cause transmission barriers substantially affect the stabilities of the local structures; for example, the G127V mutation, which makes the host resistant to various human prion diseases, greatly destabilized the local structure of the model amyloid. Our study indicates that subtle differences among hydrophobic side chains can considerably affect the interaction network, including hydrogen bonds, and demonstrates specifically how and in what structures hydrophobic residues can exert unique effects on in-register parallel β-sheet amyloids.
Collapse
Affiliation(s)
- Hiroki Otaki
- Center
for Bioinformatics and Molecular Medicine, Graduate School of Biomedical
Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
| | - Yuzuru Taguchi
- Department
of Molecular Microbiology and Immunology, Graduate School of Biomedical
Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| | - Noriyuki Nishida
- Department
of Molecular Microbiology and Immunology, Graduate School of Biomedical
Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| |
Collapse
|
2
|
Giles K, Olson SH, Prusiner SB. Developing Therapeutics for PrP Prion Diseases. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a023747. [PMID: 28096242 DOI: 10.1101/cshperspect.a023747] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The prototypical PrP prion diseases are invariably fatal, and the search for agents to treat them spans more than 30 years, with limited success. However, in the last few years, the application of high-throughput screening, medicinal chemistry, and pharmacokinetic optimization has led to important advances. The PrP prion inoculation paradigm provides a robust assay for testing therapeutic efficacy, and a dozen compounds have been reported that lead to meaningful extension in survival of prion-infected mice. Here, we review the history and recent progress in the field, focusing on studies validated in animal models. Based on screens in cells infected with mouse-passaged PrP prions, orally available compounds were generated that double or even triple the survival of mice infected with the same prion strain. Unfortunately, no compounds have yet shown efficacy against human prions. Nevertheless, the speed of the recent advances brings hope that an effective therapeutic can be developed. A successful treatment for any neurodegenerative disease would be a major achievement, and the growing understanding that the more common neurodegenerative diseases, including Alzheimer's and Parkinson's, progress by an analogous prion mechanism serves to highlight the importance of antiprion therapeutics.
Collapse
Affiliation(s)
- Kurt Giles
- Institute for Neurodegenerative Diseases, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, California 94143.,Department of Neurology, University of California, San Francisco, San Francisco, California 94143
| | - Steven H Olson
- Institute for Neurodegenerative Diseases, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, California 94143.,Department of Neurology, University of California, San Francisco, San Francisco, California 94143
| | - Stanley B Prusiner
- Institute for Neurodegenerative Diseases, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, California 94143.,Department of Neurology, University of California, San Francisco, San Francisco, California 94143.,Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, California 94143
| |
Collapse
|
3
|
Brandner S, Jaunmuktane Z. Prion disease: experimental models and reality. Acta Neuropathol 2017; 133:197-222. [PMID: 28084518 PMCID: PMC5250673 DOI: 10.1007/s00401-017-1670-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/04/2017] [Accepted: 01/05/2017] [Indexed: 01/04/2023]
Abstract
The understanding of the pathogenesis and mechanisms of diseases requires a multidisciplinary approach, involving clinical observation, correlation to pathological processes, and modelling of disease mechanisms. It is an inherent challenge, and arguably impossible to generate model systems that can faithfully recapitulate all aspects of human disease. It is, therefore, important to be aware of the potentials and also the limitations of specific model systems. Model systems are usually designed to recapitulate only specific aspects of the disease, such as a pathological phenotype, a pathomechanism, or to test a hypothesis. Here, we evaluate and discuss model systems that were generated to understand clinical, pathological, genetic, biochemical, and epidemiological aspects of prion diseases. Whilst clinical research and studies on human tissue are an essential component of prion research, much of the understanding of the mechanisms governing transmission, replication, and toxicity comes from in vitro and in vivo studies. As with other neurodegenerative diseases caused by protein misfolding, the pathogenesis of prion disease is complex, full of conundra and contradictions. We will give here a historical overview of the use of models of prion disease, how they have evolved alongside the scientific questions, and how advancements in technologies have pushed the boundaries of our understanding of prion biology.
Collapse
Affiliation(s)
- Sebastian Brandner
- Department of Neurodegenerative Disease, UCL Institute of Neurology and Division of Neuropathology, The National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, Queen Square, London, WC1N 3BG UK
| | - Zane Jaunmuktane
- Department of Neurodegenerative Disease, UCL Institute of Neurology and Division of Neuropathology, The National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, Queen Square, London, WC1N 3BG UK
| |
Collapse
|
4
|
Prusiner SB, Woerman AL, Mordes DA, Watts JC, Rampersaud R, Berry DB, Patel S, Oehler A, Lowe JK, Kravitz SN, Geschwind DH, Glidden DV, Halliday GM, Middleton LT, Gentleman SM, Grinberg LT, Giles K. Evidence for α-synuclein prions causing multiple system atrophy in humans with parkinsonism. Proc Natl Acad Sci U S A 2015; 112:E5308-17. [PMID: 26324905 PMCID: PMC4586853 DOI: 10.1073/pnas.1514475112] [Citation(s) in RCA: 515] [Impact Index Per Article: 57.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Prions are proteins that adopt alternative conformations that become self-propagating; the PrP(Sc) prion causes the rare human disorder Creutzfeldt-Jakob disease (CJD). We report here that multiple system atrophy (MSA) is caused by a different human prion composed of the α-synuclein protein. MSA is a slowly evolving disorder characterized by progressive loss of autonomic nervous system function and often signs of parkinsonism; the neuropathological hallmark of MSA is glial cytoplasmic inclusions consisting of filaments of α-synuclein. To determine whether human α-synuclein forms prions, we examined 14 human brain homogenates for transmission to cultured human embryonic kidney (HEK) cells expressing full-length, mutant human α-synuclein fused to yellow fluorescent protein (α-syn140*A53T-YFP) and TgM83(+/-) mice expressing α-synuclein (A53T). The TgM83(+/-) mice that were hemizygous for the mutant transgene did not develop spontaneous illness; in contrast, the TgM83(+/+) mice that were homozygous developed neurological dysfunction. Brain extracts from 14 MSA cases all transmitted neurodegeneration to TgM83(+/-) mice after incubation periods of ∼120 d, which was accompanied by deposition of α-synuclein within neuronal cell bodies and axons. All of the MSA extracts also induced aggregation of α-syn*A53T-YFP in cultured cells, whereas none of six Parkinson's disease (PD) extracts or a control sample did so. Our findings argue that MSA is caused by a unique strain of α-synuclein prions, which is different from the putative prions causing PD and from those causing spontaneous neurodegeneration in TgM83(+/+) mice. Remarkably, α-synuclein is the first new human prion to be identified, to our knowledge, since the discovery a half century ago that CJD was transmissible.
Collapse
Affiliation(s)
- Stanley B Prusiner
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA 94143; Department of Neurology, University of California, San Francisco, CA 94143; Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143;
| | - Amanda L Woerman
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA 94143
| | - Daniel A Mordes
- C. S. Kubik Laboratory for Neuropathology, Department of Pathology, Massachusetts General Hospital, Boston, MA 02114
| | - Joel C Watts
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA 94143; Department of Neurology, University of California, San Francisco, CA 94143
| | - Ryan Rampersaud
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA 94143
| | - David B Berry
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA 94143
| | - Smita Patel
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA 94143
| | - Abby Oehler
- Department of Pathology, University of California, San Francisco, CA 94143
| | - Jennifer K Lowe
- Center for Neurobehavioral Genetics, Center for Autism Research and Treatment, and Department of Neurology, University of California, Los Angeles, CA 90095
| | - Stephanie N Kravitz
- Center for Neurobehavioral Genetics, Center for Autism Research and Treatment, and Department of Neurology, University of California, Los Angeles, CA 90095
| | - Daniel H Geschwind
- Center for Neurobehavioral Genetics, Center for Autism Research and Treatment, and Department of Neurology, University of California, Los Angeles, CA 90095; Department of Human Genetics, University of California, Los Angeles, CA 90095
| | - David V Glidden
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA 94143
| | - Glenda M Halliday
- School of Medical Science, Faculty of Medicine, University of New South Wales, and Neuroscience Research Australia, Randwick, NSW 2031, Australia
| | - Lefkos T Middleton
- Ageing Research Unit, School of Public Health, Imperial College London, London SW7 2AZ, United Kingdom
| | - Steve M Gentleman
- Centre for Neuroinflammation and Neurodegeneration, Department of Medicine, Imperial College London, London SW7 2AZ, United Kingdom
| | - Lea T Grinberg
- Department of Neurology, University of California, San Francisco, CA 94143; Memory and Aging Center, University of California, San Francisco, CA 94143
| | - Kurt Giles
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA 94143; Department of Neurology, University of California, San Francisco, CA 94143
| |
Collapse
|
5
|
Watts JC, Giles K, Serban A, Patel S, Oehler A, Bhardwaj S, Guan S, Greicius MD, Miller BL, DeArmond SJ, Geschwind MD, Prusiner SB. Modulation of Creutzfeldt-Jakob disease prion propagation by the A224V mutation. Ann Neurol 2015; 78:540-53. [PMID: 26094969 DOI: 10.1002/ana.24463] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 06/17/2015] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Mutations in the gene encoding the prion protein (PrP) are responsible for approximately 10 to 15% of cases of prion disease in humans, including Creutzfeldt-Jakob disease (CJD). Here, we report on the discovery of a previously unreported C-terminal PrP mutation (A224V) in a CJD patient exhibiting a disease similar to the rare VV1 subtype of sporadic (s) CJD and investigate the role of this mutation in prion replication and transmission. METHODS We generated transgenic (Tg) mice expressing human PrP with the V129 polymorphism and A224V mutation, denoted Tg(HuPrP,V129,A224V) mice, and inoculated them with different subtypes of sCJD prions. RESULTS Transmission of sCJD VV2 or MV2 prions was accelerated in Tg(HuPrP,V129,A224V) mice, compared to Tg(HuPrP,V129) mice, with incubation periods of ∼110 and ∼210 days, respectively. In contrast, sCJD MM1 prions resulted in longer incubation periods in Tg(HuPrP,V129,A224V) mice, compared to Tg(HuPrP,V129) mice (∼320 vs. ∼210 days). Prion strain fidelity was maintained in Tg(HuPrP,V129,A224V) mice inoculated with sCJD VV2 or MM1 prions, despite the altered replication kinetics. INTERPRETATION Our results suggest that A224V is a risk factor for prion disease and modulates the transmission behavior of CJD prions in a strain-specific manner, arguing that residues near the C-terminus of PrP are important for controlling the kinetics of prion replication.
Collapse
Affiliation(s)
- Joel C Watts
- Institute for Neurodegenerative Diseases.,Departments of Neurology
| | - Kurt Giles
- Institute for Neurodegenerative Diseases.,Departments of Neurology
| | - Ana Serban
- Institute for Neurodegenerative Diseases
| | | | | | | | - Shenheng Guan
- Institute for Neurodegenerative Diseases.,Pharmaceutical Chemistry
| | - Michael D Greicius
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA
| | | | | | | | - Stanley B Prusiner
- Institute for Neurodegenerative Diseases.,Departments of Neurology.,Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA
| |
Collapse
|
6
|
Magnusson K, Simon R, Sjölander D, Sigurdson CJ, Hammarström P, Nilsson KPR. Multimodal fluorescence microscopy of prion strain specific PrP deposits stained by thiophene-based amyloid ligands. Prion 2014; 8:319-29. [PMID: 25495506 PMCID: PMC4601348 DOI: 10.4161/pri.29239] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The disease-associated prion protein (PrP) forms aggregates which vary in structural conformation yet share an identical primary sequence. These variations in PrP conformation are believed to manifest in prion strains exhibiting distinctly different periods of disease incubation as well as regionally specific aggregate deposition within the brain. The anionic luminescent conjugated polythiophene (LCP), polythiophene acetic acid (PTAA) has previously been used to distinguish PrP deposits associated with distinct mouse adapted strains via distinct fluorescence emission profiles from the dye. Here, we employed PTAA and 3 structurally related chemically defined luminescent conjugated oligothiophenes (LCOs) to stain brain tissue sections from mice inoculated with 2 distinct prion strains. Our results showed that in addition to emission spectra, excitation, and fluorescence lifetime imaging microscopy (FLIM) can fruitfully be assessed for optical distinction of PrP deposits associated with distinct prion strains. Our findings support the theory that alterations in LCP/LCO fluorescence are due to distinct conformational restriction of the thiophene backbone upon interaction with PrP aggregates associated with distinct prion strains. We foresee that LCP and LCO staining in combination with multimodal fluorescence microscopy might aid in detecting structural differences among discrete protein aggregates and in linking protein conformational features with disease phenotypes for a variety of neurodegenerative proteinopathies.
Collapse
Affiliation(s)
- Karin Magnusson
- a Department of Chemistry ; Linköping University ; Linköping , Sweden
| | | | | | | | | | | |
Collapse
|
7
|
Watts JC, Prusiner SB. Mouse models for studying the formation and propagation of prions. J Biol Chem 2014; 289:19841-9. [PMID: 24860095 DOI: 10.1074/jbc.r114.550707] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Prions are self-propagating protein conformers that cause a variety of neurodegenerative disorders in humans and animals. Mouse models have played key roles in deciphering the biology of prions and in assessing candidate therapeutics. The development of transgenic mice that form prions spontaneously in the brain has advanced our understanding of sporadic and genetic prion diseases. Furthermore, the realization that many proteins can become prions has necessitated the development of mouse models for assessing the potential transmissibility of common neurodegenerative diseases. As the universe of prion diseases continues to expand, mouse models will remain crucial for interrogating these devastating illnesses.
Collapse
Affiliation(s)
- Joel C Watts
- From the Institute for Neurodegenerative Diseases and the Department of Neurology, University of California, San Francisco, California 94143
| | - Stanley B Prusiner
- From the Institute for Neurodegenerative Diseases and the Department of Neurology, University of California, San Francisco, California 94143
| |
Collapse
|
8
|
Abstract
Prions are proteins that acquire alternative conformations that become self-propagating. Transformation of proteins into prions is generally accompanied by an increase in β-sheet structure and a propensity to aggregate into oligomers. Some prions are beneficial and perform cellular functions, whereas others cause neurodegeneration. In mammals, more than a dozen proteins that become prions have been identified, and a similar number has been found in fungi. In both mammals and fungi, variations in the prion conformation encipher the biological properties of distinct prion strains. Increasing evidence argues that prions cause many neurodegenerative diseases (NDs), including Alzheimer's, Parkinson's, Creutzfeldt-Jakob, and Lou Gehrig's diseases, as well as the tauopathies. The majority of NDs are sporadic, and 10% to 20% are inherited. The late onset of heritable NDs, like their sporadic counterparts, may reflect the stochastic nature of prion formation; the pathogenesis of such illnesses seems to require prion accumulation to exceed some critical threshold before neurological dysfunction manifests.
Collapse
Affiliation(s)
- Stanley B Prusiner
- Institute for Neurodegenerative Diseases and Department of Neurology, University of California, San Francisco, California 94143;
| |
Collapse
|
9
|
Watts JC, Giles K, Patel S, Oehler A, DeArmond SJ, Prusiner SB. Evidence that bank vole PrP is a universal acceptor for prions. PLoS Pathog 2014; 10:e1003990. [PMID: 24699458 PMCID: PMC3974871 DOI: 10.1371/journal.ppat.1003990] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 01/28/2014] [Indexed: 12/29/2022] Open
Abstract
Bank voles are uniquely susceptible to a wide range of prion strains isolated from many different species. To determine if this enhanced susceptibility to interspecies prion transmission is encoded within the sequence of the bank vole prion protein (BVPrP), we inoculated Tg(M109) and Tg(I109) mice, which express BVPrP containing either methionine or isoleucine at polymorphic codon 109, with 16 prion isolates from 8 different species: humans, cattle, elk, sheep, guinea pigs, hamsters, mice, and meadow voles. Efficient disease transmission was observed in both Tg(M109) and Tg(I109) mice. For instance, inoculation of the most common human prion strain, sporadic Creutzfeldt-Jakob disease (sCJD) subtype MM1, into Tg(M109) mice gave incubation periods of ∼200 days that were shortened slightly on second passage. Chronic wasting disease prions exhibited an incubation time of ∼250 days, which shortened to ∼150 days upon second passage in Tg(M109) mice. Unexpectedly, bovine spongiform encephalopathy and variant CJD prions caused rapid neurological dysfunction in Tg(M109) mice upon second passage, with incubation periods of 64 and 40 days, respectively. Despite the rapid incubation periods, other strain-specified properties of many prion isolates—including the size of proteinase K–resistant PrPSc, the pattern of cerebral PrPSc deposition, and the conformational stability—were remarkably conserved upon serial passage in Tg(M109) mice. Our results demonstrate that expression of BVPrP is sufficient to engender enhanced susceptibility to a diverse range of prion isolates, suggesting that BVPrP may be a universal acceptor for prions. Prions are infectious proteins that cause devastating neurodegenerative diseases in both humans and animals. Unlike other rodents, bank voles are highly susceptible to prions from many different species, suggesting that bank voles do not impose a “species barrier,” which normally restricts the transmission of prions from one species to another. We were curious as to whether the unprecedented promiscuity of bank voles for prions is due to the specific prion protein sequence expressed, or to some other factor inherent to bank vole physiology. To answer this question, we inoculated transgenic mice that express bank vole prion protein [Tg(BVPrP) mice] with a diverse set of prions deriving from eight different species. Like bank voles, Tg(BVPrP) mice were highly susceptible to prions from all species tested, demonstrating that the BVPrP sequence mediates the enhanced susceptibility of bank voles to prions. Because the amino acid sequences of mouse and BVPrP differ at only eight positions, our results demonstrate that alterations to a small subset of residues within PrP can have a profound effect on the susceptibility of an organism to prions from another species.
Collapse
Affiliation(s)
- Joel C Watts
- Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California, United States of America; Department of Neurology, University of California, San Francisco, San Francisco, California, United States of America
| | - Kurt Giles
- Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California, United States of America; Department of Neurology, University of California, San Francisco, San Francisco, California, United States of America
| | - Smita Patel
- Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California, United States of America
| | - Abby Oehler
- Department of Pathology, University of California, San Francisco, San Francisco, California, United States of America
| | - Stephen J DeArmond
- Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California, United States of America; Department of Pathology, University of California, San Francisco, San Francisco, California, United States of America
| | - Stanley B Prusiner
- Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California, United States of America; Department of Neurology, University of California, San Francisco, San Francisco, California, United States of America
| |
Collapse
|
10
|
Abstract
There is not a single pharmaceutical that halts or even slows any neurodegenerative disease. Mounting evidence shows that prions cause many neurodegenerative diseases, and arguably, scrapie and Creutzfeldt-Jakob disease prions represent the best therapeutic targets. We report here that the previously identified 2-aminothiazoles IND24 and IND81 doubled the survival times of scrapie-infected, wild-type mice. However, mice infected with Rocky Mountain Laboratory (RML) prions, a scrapie-derived strain, and treated with IND24 eventually exhibited neurological dysfunction and died. We serially passaged their brain homogenates in mice and cultured cells. We found that the prion strain isolated from IND24-treated mice, designated RML[IND24], emerged during a single passage in treated mice. Although RML prions infect both the N2a and CAD5 cell lines, RML[IND24] prions could only infect CAD5 cells. When passaged in CAD5 cells, the prions remained resistant to high concentrations of IND24. However, one passage of RML[IND24] prions in untreated mice restored susceptibility to IND24 in CAD5 cells. Although IND24 treatment extended the lives of mice propagating different prion strains, including RML, another scrapie-derived prion strain ME7, and chronic wasting disease, it was ineffective in slowing propagation of Creutzfeldt-Jakob disease prions in transgenic mice. Our studies demonstrate that prion strains can acquire resistance upon exposure to IND24 that is lost upon passage in mice in the absence of IND24. These data suggest that monotherapy can select for resistance, thus intermittent therapy with mixtures of antiprion compounds may be required to slow or stop neurodegeneration.
Collapse
|
11
|
Tamgüney G, Giles K, Oehler A, Johnson NL, DeArmond SJ, Prusiner SB. Chimeric elk/mouse prion proteins in transgenic mice. J Gen Virol 2012; 94:443-452. [PMID: 23100369 DOI: 10.1099/vir.0.045989-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Chronic wasting disease (CWD) of deer and elk is a highly communicable neurodegenerative disorder caused by prions. Investigations of CWD are hampered by slow bioassays in transgenic (Tg) mice. Towards the development of Tg mice that will be more susceptible to CWD prions, we created a series of chimeric elk/mouse transgenes that encode the N terminus of elk PrP (ElkPrP) up to residue Y168 and the C terminus of mouse PrP (MoPrP) beyond residue 169 (mouse numbering), designated Elk3M(SNIVVK). Between codons 169 and 219, six residues distinguish ElkPrP from MoPrP: N169S, T173N, V183I, I202V, I214V and R219K. Using chimeric elk/mouse PrP constructs, we generated 12 Tg mouse lines and determined incubation times after intracerebral inoculation with the mouse-passaged RML scrapie or Elk1P CWD prions. Unexpectedly, one Tg mouse line expressing Elk3M(SNIVVK) exhibited incubation times of <70 days when inoculated with RML prions; a second line had incubation times of <90 days. In contrast, mice expressing full-length ElkPrP had incubation periods of >250 days for RML prions. Tg(Elk3M,SNIVVK) mice were less susceptible to CWD prions than Tg(ElkPrP) mice. Changing three C-terminal mouse residues (202, 214 and 219) to those of elk doubled the incubation time for mouse RML prions and rendered the mice resistant to Elk1P CWD prions. Mutating an additional two residues from mouse to elk at codons 169 and 173 increased the incubation times for mouse prions to >300 days, but made the mice susceptible to CWD prions. Our findings highlight the role of C-terminal residues in PrP that control the susceptibility and replication of prions.
Collapse
Affiliation(s)
- Gültekin Tamgüney
- Department of Neurology, University of California, San Francisco, CA, USA.,Institute for Neurodegenerative Diseases, University of California, San Francisco, CA, USA
| | - Kurt Giles
- Department of Neurology, University of California, San Francisco, CA, USA.,Institute for Neurodegenerative Diseases, University of California, San Francisco, CA, USA
| | - Abby Oehler
- Department of Pathology, University of California, San Francisco, CA, USA
| | - Natrina L Johnson
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA, USA
| | - Stephen J DeArmond
- Department of Pathology, University of California, San Francisco, CA, USA.,Institute for Neurodegenerative Diseases, University of California, San Francisco, CA, USA
| | - Stanley B Prusiner
- Department of Neurology, University of California, San Francisco, CA, USA.,Institute for Neurodegenerative Diseases, University of California, San Francisco, CA, USA
| |
Collapse
|