1
|
Banks WA, Robinson SM, Diaz-Espinoza R, Urayama A, Soto C. Transport of prion protein across the blood-brain barrier. Exp Neurol 2009; 218:162-7. [PMID: 19422824 PMCID: PMC2806677 DOI: 10.1016/j.expneurol.2009.04.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Revised: 04/22/2009] [Accepted: 04/28/2009] [Indexed: 10/20/2022]
Abstract
The cellular form of the prion protein (PrP(c)) is necessary for the development of prion diseases and is a highly conserved protein that may play a role in neuroprotection. PrP(c) is found in both blood and cerebrospinal fluid and is likely produced by both peripheral tissues and the central nervous system (CNS). Exchange of PrP(c) between the brain and peripheral tissues could have important pathophysiologic and therapeutic implications, but it is unknown whether PrP(c) can cross the blood-brain barrier (BBB). Here, we found that radioactively labeled PrP(c) crossed the BBB in both the brain-to-blood and blood-to-brain directions. PrP(c) was enzymatically stable in blood and in brain, was cleared by liver and kidney, and was sequestered by spleen and the cervical lymph nodes. Circulating PrP(c) entered all regions of the CNS, but uptake by the lumbar and cervical spinal cord, hypothalamus, thalamus, and striatum was particularly high. These results show that PrP(c) has bidirectional, saturable transport across the BBB and selectively targets some CNS regions. Such transport may play a role in PrP(c) function and prion replication.
Collapse
Affiliation(s)
- W A Banks
- GRECC, Veterans Affairs Medical Center-St. Louis, MO, USA.
| | | | | | | | | |
Collapse
|
2
|
Jeffrey M, González L, Espenes A, Press CM, Martin S, Chaplin M, Davis L, Landsverk T, MacAldowie C, Eaton S, McGovern G. Transportation of prion protein across the intestinal mucosa of scrapie-susceptible and scrapie-resistant sheep. J Pathol 2006; 209:4-14. [PMID: 16575799 DOI: 10.1002/path.1962] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
To determine the mechanisms of intestinal transport of infection, and early pathogenesis, of sheep scrapie, isolated gut-loops were inoculated to ensure that significant concentrations of scrapie agent would come into direct contact with the relevant ileal structures (epithelial, lymphoreticular, and nervous). Gut loops were inoculated with a scrapie brain pool homogenate or normal brain or sucrose solution. After surgery, animals were necropsied at time points ranging from 15 min to 1 month and at clinical end point. Inoculum-associated prion protein (PrP) was detected by immunohistochemistry in villous lacteals and in sub-mucosal lymphatics from 15 min to 3.5 h post-challenge. It was also detected in association with dendritic-like cells in the draining lymph nodes at up to 24 h post-challenge. Replication of infection, as demonstrated by the accumulation of disease-associated forms of PrP in Peyer's patches, was detected at 30 days and sheep developed clinical signs of scrapie at 18-22 months post-challenge. These results indicate discrepancies between the routes of transportation of PrP from the inoculum and sites of de novo-generated disease-associated PrP subsequent to scrapie agent replication. When samples of homogenized inoculum were incubated with alimentary tract fluids in vitro, only trace amounts of protease-resistant PrP could be detected by western blotting, suggesting that the majority of both normal and abnormal PrP within the inoculum is readily digested by alimentary fluids.
Collapse
Affiliation(s)
- M Jeffrey
- Veterinary Laboratories Agency (VLA)-Lasswade, Pentlands Science Park, Midlothian, UK.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
3
|
Johnson CJ, Phillips KE, Schramm PT, McKenzie D, Aiken JM, Pedersen JA. Prions adhere to soil minerals and remain infectious. PLoS Pathog 2006; 2:e32. [PMID: 16617377 PMCID: PMC1435987 DOI: 10.1371/journal.ppat.0020032] [Citation(s) in RCA: 189] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Accepted: 03/08/2006] [Indexed: 11/30/2022] Open
Abstract
An unidentified environmental reservoir of infectivity contributes to the natural transmission of prion diseases (transmissible spongiform encephalopathies [TSEs]) in sheep, deer, and elk. Prion infectivity may enter soil environments via shedding from diseased animals and decomposition of infected carcasses. Burial of TSE-infected cattle, sheep, and deer as a means of disposal has resulted in unintentional introduction of prions into subsurface environments. We examined the potential for soil to serve as a TSE reservoir by studying the interaction of the disease-associated prion protein (PrPSc) with common soil minerals. In this study, we demonstrated substantial PrPSc adsorption to two clay minerals, quartz, and four whole soil samples. We quantified the PrPSc-binding capacities of each mineral. Furthermore, we observed that PrPSc desorbed from montmorillonite clay was cleaved at an N-terminal site and the interaction between PrPSc and Mte was strong, making desorption of the protein difficult. Despite cleavage and avid binding, PrPSc bound to Mte remained infectious. Results from our study suggest that PrPSc released into soil environments may be preserved in a bioavailable form, perpetuating prion disease epizootics and exposing other species to the infectious agent. Transmissible spongiform encephalopathies (TSEs) are a group of incurable diseases likely caused by a misfolded form of the prion protein (PrPSc). TSEs include scrapie in sheep, bovine spongiform encephalopathy (“mad cow” disease) in cattle, chronic wasting disease (CWD) in deer and elk, and Creutzfeldt-Jakob disease in humans. Scrapie and CWD are unique among TSEs because they can be transmitted between animals, and the disease agents appear to persist in environments previously inhabited by infected animals. Soil has been hypothesized to act as a reservoir of infectivity, because PrPSc likely enters soil environments through urinary or alimentary shedding and decomposition of infected animals. In this manuscript, the authors test the potential for soil to serve as a reservoir for PrPSc and TSE infectivity. They demonstrate that PrPSc binds to a variety of soil minerals and to whole soils. They also quantitate the levels of protein binding to three common soil minerals and show that the interaction of PrPSc with montmorillonite, a common clay mineral, is remarkably strong. PrPSc bound to Mte remained infectious to laboratory animals, suggesting that soil can serve as a reservoir of TSE infectivity.
Collapse
Affiliation(s)
- Christopher J Johnson
- Program in Cellular and Molecular Biology, University of Wisconsin Madison, Madison, Wisconsin, United States of America
- Department of Animal Health and Biomedical Sciences, School of Veterinary Medicine, University of Wisconsin Madison, Madison, Wisconsin, United States of America
| | - Kristen E Phillips
- Molecular and Environmental Toxicology Center, University of Wisconsin Madison, Madison, Wisconsin, United States of America
| | - Peter T Schramm
- Molecular and Environmental Toxicology Center, University of Wisconsin Madison, Madison, Wisconsin, United States of America
| | - Debbie McKenzie
- Department of Animal Health and Biomedical Sciences, School of Veterinary Medicine, University of Wisconsin Madison, Madison, Wisconsin, United States of America
| | - Judd M Aiken
- Program in Cellular and Molecular Biology, University of Wisconsin Madison, Madison, Wisconsin, United States of America
- Department of Animal Health and Biomedical Sciences, School of Veterinary Medicine, University of Wisconsin Madison, Madison, Wisconsin, United States of America
| | - Joel A Pedersen
- Molecular and Environmental Toxicology Center, University of Wisconsin Madison, Madison, Wisconsin, United States of America
- Department of Soil Science, University of Wisconsin Madison, Madison, Wisconsin, United States of America
- * To whom correspondence should be addressed. E-mail:
| |
Collapse
|
4
|
Revault M, Quiquampoix H, Baron MH, Noinville S. Fate of prions in soil: trapped conformation of full-length ovine prion protein induced by adsorption on clays. Biochim Biophys Acta Gen Subj 2005; 1724:367-74. [PMID: 15950385 DOI: 10.1016/j.bbagen.2005.05.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2005] [Revised: 04/25/2005] [Accepted: 05/04/2005] [Indexed: 11/20/2022]
Abstract
Studying the mechanism of retention of ovine prion protein in soils will tackle the environmental aspect of potential dissemination of scrapie infectious agent. We consider the surface-induced conformational changes that the recombinant ovine prion protein (ovPrP) may undergo under different pH conditions when interacting with soil minerals of highly adsorptive capacities such as montmorillonite. The conformational states of the full-length ovine prion protein adsorbed on the electronegative clay surface are compared to its solvated state in deuterated buffer in the pD range 3.5-9, using FTIR spectroscopy. The in vitro pH-induced conversion of the alpha-helical monomer of ovPrP into oligomers of beta-like structure prone to self-aggregation does not occur when the protein is adsorbed on the clay surface. The conformation of the trapped ovPrP molecules on montmorillonite is pH-independent and looks like that of the ovPrP solvated state at pD higher than 7, suggesting the major role of Arg and Lys residues in the electrostatic origin of adsorption. The uneven distribution of positively and negatively charged residues of the ovPrP protein would promote a favored orientation of the protein towards the clay, so that not only the basic residues embedded in the N-terminal flexible part but also external basic residues in the globular part of the protein might participate to the attractive interaction. From these results, it appears unlikely that the interaction of normal prions (PrP(C)) with soil clay surfaces could induce a change of conformation leading to the pathogenic form of prions (PrP(Sc)).
Collapse
Affiliation(s)
- M Revault
- Laboratoire de Dynamique, Interactions et Réactivité CNRS-Université Pierre et Marie Curie, UMR 7075, 2 rue Henri Dunant, 94320 Thiais, France
| | | | | | | |
Collapse
|
5
|
Mabbott N, Turner M. Prions and the blood and immune systems. Haematologica 2005; 90:542-8. [PMID: 15820951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023] Open
Abstract
Prion diseases take a number of forms in animals and humans. They are caused by conformational change in widely expressed prion protein leading to the formation of intracellular aggregates. Although the main focus of disease is the central nervous system, it is known that involvement of the immune system occurs in peripherally transmitted disease in particular. Animal experiments suggest that in some prion diseases follicular dendritic cells in the germinal centers are a major site of initial accumulation, and that abnormal prion protein and infectivity are detectable in peripheral lymphoid tissue from the earliest phase of disease. This raises the possibility that in a human peripherally transmitted prion disease like variant Creutzfeldt-Jakob disease, further transmission could occur through blood or tissue products or contamination of surgical instrumentation. Indeed two recent reports confirm that this disease has been transmitted by blood, raising significant public health concerns.
Collapse
|
6
|
|
7
|
Abstract
In this article we give an overview of the transmissible spongiform encephalopathies, with emphasis on the evidence for the distribution of abnormal prions in tissues. The normal prion protein is distributed ubiquitously throughout human body tissues. Endogenous expression of the normal prion protein, as well as auxiliary proteins, plays a part in accumulation of the abnormal prion protein. As exemplified by variant Creutzfeldt-Jakob disease (vCJD) the abnormal prion protein can accumulate in the host lymphoid system, in particular the follicular dendritic cells. The route for the disease-related prion neuroinvasion is likely to involve the peripheral nervous system. An alternative route may involve blood constituents. Both animal studies and studies on vCJD patients suggest a potential for abnormal prion distribution in several peripheral tissues other than the lymphoreticular system. In human beings the abnormal prion has been reported in the brain, tonsils, spleen, lymph node, retina, and proximal optic nerve. Infectivity, although present in peripheral tissues, is at lower levels than in the central nervous system (CNS). Animal models suggest that the growth of infectivity in the CNS is likely to be gradual with maximum values during the clinical phase of disease. That tissues may harbour the abnormal prion, at different levels of infectivity, during the incubation period of the disease raises concerns of iatrogenic transmission of the disease either after surgery, blood transfusion, or accidental organ transplantation from donors in the preclinical phase of the disease.
Collapse
Affiliation(s)
- I Ramasamy
- Communicable Diseases and Environmental Health Branch, Department of Health, Canberra, ACT, Australia.
| | | | | | | |
Collapse
|
8
|
Numao N, Noguchi N, Eguchi Y, Watanabe S, Fukui T, Kamino T, Shimozono N, Yamazaki A, Kobayashi S, Sasatsu M. Novel biological activity of the region (106-126) on human prion sequence. Biol Pharm Bull 2003; 26:229-32. [PMID: 12576685 DOI: 10.1248/bpb.26.229] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We report that the synthetic peptide Prp106-126 (KTNMKHMAGAAAAGAVVGGLG-COOH) and the reversed peptide Prp126-106 (GLGGVVAGAAAAGAMHKMNTK-COOH) of human prion (hPrp) can express the decarboxylase activity for oxaloacetate in the presence of trifluoroethanol, similar to that of Oxaldie 1 (LAKLLKALAKLLKK-CONH2) reported previously. The degree of the relative activity of Prp106-126 and Prp126-106 to Oxaldie 1 is 0.47 and 0.21, respectively. Based on this experimental result, we applied the informational system method (ISM) developed by Veljkovic et al. to the amino acid sequence of Prp106-126 and Prp126-106 to extract a common factor. The same spectra were obtained, indicating that the same periodicity may be conserved on their sequences, as a necessary factor for expressing the same biological activity, irrespective of the orientation of the primary sequence.
Collapse
|
9
|
Abstract
The aetiological agent of prion disease is proposed to be an aberrant isoform of the cell surface glycoprotein known as the prion protein (PrP(c)). This pathological isoform (PrP(Sc)) is abnormally deposited in the extracellular space of diseased CNS. Neurodegeneration in these disease has been shown to be associated with accumulation of PrP(Sc) in affected tissue. To investigate the possible uptake mechanisms that may be required for PrP(Sc)-induced neurodegeneration we studied the cellular trafficking of the neurotoxic fragment, PrP106-126. We were able to detect, by fluorescence microscopy, PrP106-126 inclusions in murine neurones, astrocytes and microglia in vitro. These inclusions were abundant after 24 hour exposure and still present 48h post-exposure. Shorter exposure times yielded only occasional cells with inclusions. Large extracellular aggregates of PrP106-126 could also be detected, which appeared in a time dependent manner. The appearance of inclusions or aggregates was not dependent on PrP(c) expression as determined by exposure of peptides from PrP-null mice. Using transmission electron microscopy and gold particle detection, positively labelled osmiophilic inclusions of peptide could be detected in the cytoplasm of exposed cells. These results demonstrate that cultured cells are capable of sequestering PrP106-126 and may indicate uptake pathways for PrP(Sc) in various cell types. Toxicity of PrP106-126 may thus be mediated via a sequestration pathway that is not effective for this peptide in PrP-null cells.
Collapse
Affiliation(s)
- S J McHattie
- Biomedical Sciences, Queen Mary and Westfield College, Mile End Road, London E1 4NS, UK
| | | | | |
Collapse
|
10
|
Abstract
Prion titres were measured in the lungs and brains of Syrian hamsters after intraperitoneal inoculation with sucrose gradient-purified 263K prions (approximately 10(8) LD50). Prions were detected in the lung of one hamster on day 7, but were not detected in the lungs of any other hamster until day 71. Prions were detected in the lungs of all hamsters sampled thereafter but titres remained low through day 127. Prions were first detected in the brain on day 35 and brain titres increased exponentially until day 127 with a doubling time of about 4.5 days. On day 133, titres averaged 10(8.0) LD50/g in brain and 10(5.0) LD50/g in lung. Two out of the five remaining hamsters were clinically normal but prion titres were not significantly different from those in the clinically affected hamsters. Thus, significant prion titres may be found outside the CNS in clinically normal hamsters.
Collapse
Affiliation(s)
- D C Bolton
- Department of Molecular Biology, New York State Institute for Basic Research, Office of Mental Retardation and Developmental Disabilities, Staten Island 10314, USA.
| |
Collapse
|