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Mice Treated Subcutaneously with Mouse LPS-Converted PrP res or LPS Alone Showed Brain Gene Expression Profiles Characteristic of Prion Disease. Vet Sci 2021; 8:vetsci8090200. [PMID: 34564594 PMCID: PMC8473295 DOI: 10.3390/vetsci8090200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 11/16/2022] Open
Abstract
Previously, we showed that bacterial lipopolysaccharide (LPS) converts mouse PrPC protein to a beta-rich isoform (moPrPres) resistant to proteinase K. In this study, we aimed to test if the LPS-converted PrPres is infectious and alters the expression of genes related to prion pathology in brains of terminally sick mice. Ninety female FVB/N mice at 5 weeks of age were randomly assigned to 6 groups treated subcutaneously (sc) for 6 weeks either with: (1) Saline (CTR); (2) LPS from Escherichia coli 0111:B4 (LPS), (3) one-time sc administration of de novo generated mouse recombinant prion protein (moPrP; 29-232) rich in beta-sheet by incubation with LPS (moPrPres), (4) LPS plus one-time sc injection of moPrPres, (5) one-time sc injection of brain homogenate from Rocky Mountain Lab (RLM) scrapie strain, and (6) LPS plus one-time sc injection of RML. Results showed that all treatments altered the expression of various genes related to prion disease and neuroinflammation starting at 11 weeks post-infection and more profoundly at the terminal stage. In conclusion, sc administration of de novo generated moPrPres, LPS, and a combination of moPrPres with LPS were able to alter the expression of multiple genes typical of prion pathology and inflammation.
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Striebel JF, Race B, Leung JM, Schwartz C, Chesebro B. Prion-induced photoreceptor degeneration begins with misfolded prion protein accumulation in cones at two distinct sites: cilia and ribbon synapses. Acta Neuropathol Commun 2021; 9:17. [PMID: 33509294 PMCID: PMC7845122 DOI: 10.1186/s40478-021-01120-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 01/09/2021] [Indexed: 12/15/2022] Open
Abstract
Accumulation of misfolded host proteins is central to neuropathogenesis of numerous human brain diseases including prion and prion-like diseases. Neurons of retina are also affected by these diseases. Previously, our group and others found that prion-induced retinal damage to photoreceptor cells in mice and humans resembled pathology of human retinitis pigmentosa caused by mutations in retinal proteins. Here, using confocal, epifluorescent and electron microscopy we followed deposition of disease-associated prion protein (PrPSc) and its association with damage to critical retinal structures following intracerebral prion inoculation. The earliest time and place of retinal PrPSc deposition was 67 days post-inoculation (dpi) on the inner segment (IS) of cone photoreceptors. At 104 and 118 dpi, PrPSc was associated with the base of cilia and swollen cone inner segments, suggesting ciliopathy as a pathogenic mechanism. By 118 dpi, PrPSc was deposited in both rods and cones which showed rootlet damage in the IS, and photoreceptor cell death was indicated by thinning of the outer nuclear layer. In the outer plexiform layer (OPL) in uninfected mice, normal host PrP (PrPC) was mainly associated with cone bipolar cell processes, but in infected mice, at 118 dpi, PrPSc was detected on cone and rod bipolar cell dendrites extending into ribbon synapses. Loss of ribbon synapses in cone pedicles and rod spherules in the OPL was observed to precede destruction of most rods and cones over the next 2–3 weeks. However, bipolar cells and horizontal cells were less damaged, indicating high selectivity among neurons for injury by prions. PrPSc deposition in cone and rod inner segments and on the bipolar cell processes participating in ribbon synapses appear to be critical early events leading to damage and death of photoreceptors after prion infection. These mechanisms may also occur in human retinitis pigmentosa and prion-like diseases, such as AD.
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Orrù CD, Soldau K, Cordano C, Llibre-Guerra J, Green AJ, Sanchez H, Groveman BR, Edland SD, Safar JG, Lin JH, Caughey B, Geschwind MD, Sigurdson CJ. Prion Seeds Distribute throughout the Eyes of Sporadic Creutzfeldt-Jakob Disease Patients. mBio 2018; 9:e02095-18. [PMID: 30459197 PMCID: PMC6247090 DOI: 10.1128/mbio.02095-18] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 10/04/2018] [Indexed: 12/16/2022] Open
Abstract
Sporadic Creutzfeldt-Jakob disease (sCJD) is the most common prion disease in humans and has been iatrogenically transmitted through corneal graft transplantation. Approximately 40% of sCJD patients develop visual or oculomotor symptoms and may seek ophthalmological consultation. Here we used the highly sensitive real-time quaking-induced conversion (RT-QuIC) assay to measure postmortem prion seeding activities in cornea, lens, ocular fluid, retina, choroid, sclera, optic nerve, and extraocular muscle in the largest series of sCJD patient eyes studied by any assay to date. We detected prion seeding activity in 100% of sCJD eyes, representing three common sCJD subtypes, with levels varying by up to 4 log-fold among individuals. The retina consistently showed the highest seed levels, which in some cases were only slightly lower than brain. Within the retina, prion deposits were detected by immunohistochemistry (IHC) in the retinal outer plexiform layer in most sCJD cases, and in some eyes the inner plexiform layer, consistent with synaptic prion deposition. Prions were not detected by IHC in any other eye region. With RT-QuIC, prion seed levels generally declined in eye tissues with increased distance from the brain, and yet all corneas had prion seeds detectable. Prion seeds were also present in the optic nerve, extraocular muscle, choroid, lens, vitreous, and sclera. Collectively, these results reveal that sCJD patients accumulate prion seeds throughout the eye, indicating the potential diagnostic utility as well as a possible biohazard.IMPORTANCE Cases of iatrogenic prion disease have been reported from corneal transplants, yet the distribution and levels of prions throughout the eye remain unknown. This study probes the occurrence, level, and distribution of prions in the eyes of patients with sporadic Creutzfeldt-Jakob disease (sCJD). We tested the largest series of prion-infected eyes reported to date using an ultrasensitive technique to establish the prion seed levels in eight regions of the eye. All 11 cases had detectable prion seeds in the eye, and in some cases, the seed levels in the retina approached those in brain. In most cases, prion deposits could also be seen by immunohistochemical staining of retinal tissue; other ocular tissues were negative. Our results have implications for estimating the risk for iatrogenic transmission of sCJD as well as for the development of antemortem diagnostic tests for prion diseases.
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Affiliation(s)
- Christina D Orrù
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Hamilton, Montana, USA
| | - Katrin Soldau
- Department of Pathology, University of California, San Diego, La Jolla, California, USA
| | - Christian Cordano
- Department of Neurology, Multiple Sclerosis Center, University of California, San Francisco (UCSF), San Francisco, California, USA
| | - Jorge Llibre-Guerra
- Cognitive and Behavioral Research Unit, National Institute of Neurology, Havana, Cuba
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California, USA
| | - Ari J Green
- Department of Neurology, Multiple Sclerosis Center, University of California, San Francisco (UCSF), San Francisco, California, USA
| | - Henry Sanchez
- Department of Pathology, University of California, San Francisco (UCSF), San Francisco, California, USA
| | - Bradley R Groveman
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Hamilton, Montana, USA
| | - Steven D Edland
- Department of Family Medicine & Public Health, University of California, San Diego, La Jolla, California, USA
- Department of Neurosciences, University of California, San Diego, La Jolla, California, USA
| | - Jiri G Safar
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Neurology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Jonathan H Lin
- Department of Pathology, University of California, San Diego, La Jolla, California, USA
| | - Byron Caughey
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Hamilton, Montana, USA
| | - Michael D Geschwind
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California, USA
| | - Christina J Sigurdson
- Department of Pathology, University of California, San Diego, La Jolla, California, USA
- Department of Pathology, Immunology, and Microbiology, University of California, Davis, Davis, California, USA
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Yen CF, Harischandra DS, Kanthasamy A, Sivasankar S. Copper-induced structural conversion templates prion protein oligomerization and neurotoxicity. SCIENCE ADVANCES 2016; 2:e1600014. [PMID: 27419232 PMCID: PMC4942324 DOI: 10.1126/sciadv.1600014] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 05/27/2016] [Indexed: 05/26/2023]
Abstract
Prion protein (PrP) misfolding and oligomerization are key pathogenic events in prion disease. Copper exposure has been linked to prion pathogenesis; however, its mechanistic basis is unknown. We resolve, with single-molecule precision, the molecular mechanism of Cu(2+)-induced misfolding of PrP under physiological conditions. We also demonstrate that misfolded PrPs serve as seeds for templated formation of aggregates, which mediate inflammation and degeneration of neuronal tissue. Using a single-molecule fluorescence assay, we demonstrate that Cu(2+) induces PrP monomers to misfold before oligomer assembly; the disordered amino-terminal region mediates this structural change. Single-molecule force spectroscopy measurements show that the misfolded monomers have a 900-fold higher binding affinity compared to the native isoform, which promotes their oligomerization. Real-time quaking-induced conversion demonstrates that misfolded PrPs serve as seeds that template amyloid formation. Finally, organotypic slice cultures show that misfolded PrPs mediate inflammation and degeneration of neuronal tissue. Our study establishes a direct link, at the molecular level, between copper exposure and PrP neurotoxicity.
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Affiliation(s)
- Chi-Fu Yen
- Department of Electrical and Computer Engineering, Iowa State University, Ames, IA 50011, USA
| | - Dilshan S. Harischandra
- Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Anumantha Kanthasamy
- Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Sanjeevi Sivasankar
- Department of Electrical and Computer Engineering, Iowa State University, Ames, IA 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA
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EGCG-mediated autophagy flux has a neuroprotection effect via a class III histone deacetylase in primary neuron cells. Oncotarget 2016; 6:9701-17. [PMID: 25991666 PMCID: PMC4496391 DOI: 10.18632/oncotarget.3832] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 03/26/2015] [Indexed: 01/04/2023] Open
Abstract
Prion diseases caused by aggregated misfolded prion protein (PrP) are transmissible neurodegenerative disorders that occur in both humans and animals. Epigallocatechin-3-gallate (EGCG) has preventive effects on prion disease; however, the mechanisms related to preventing prion diseases are unclear. We investigated whether EGCG, the main polyphenol in green tea, prevents neuron cell damage induced by the human prion protein. We also studied the neuroprotective mechanisms and proper signals mediated by EGCG. The results showed that EGCG protects the neuronal cells against human prion protein-induced damage through inhibiting Bax and cytochrome c translocation and autophagic pathways by increasing LC3-II and reducing and blocking p62 by using ATG5 small interfering (si) RNA and autophagy inhibitors. We further demonstrated that the neuroprotective effects of EGCG were exhibited by a class III histone deacetylase; sirt1 activation and the neuroprotective effects attenuated by sirt1 inactivation using sirt1 siRNA and sirtinol. We demonstrated that EGCG activated the autophagic pathways by inducing sirt1, and had protective effects against human prion protein-induced neuronal cell toxicity. These results suggest that EGCG may be a therapeutic agent for treatment of neurodegenerative disorders including prion diseases.
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Long time remodeling during retinal degeneration evaluated by optical coherence tomography, immunocytochemistry and fundus autofluorescence. Exp Eye Res 2015; 150:122-34. [PMID: 26521765 DOI: 10.1016/j.exer.2015.10.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Revised: 10/13/2015] [Accepted: 10/15/2015] [Indexed: 01/16/2023]
Abstract
PURPOSE To characterize the relationship between fundus autofluorescence (FAF), Optical Coherence Tomography (OCT) and immunohistochemistry (IHC) over the course of chronic retinal degeneration in the P23H rat. METHODS Homozygous albino P23H rats, Sprague-Dawley (SD) rats as controls and pigmented Long Evans (LE) rats were used. A Spectralis HRA OCT system was used for scanning laser ophthalmoscopy (SLO) imaging OCT and angiography. To determine FAF, fluorescence was excited using diode laser at 488 nm. A fast retina map OCT was performed using the optic nerve as a landmark. IHC was performed to correlate with the findings of OCT and FAF changes. RESULTS During the course of retinal degeneration, the FAF pattern evolved from some spotting at 2 months old to a mosaic of hyperfluorescent dots in rats 6 months and older. Retinal thicknesses progressively diminished over the course of the disease. At later stages of degeneration, OCT documented changes in the retinal layers, however, IHC better identified the cell loss and remodeling changes. Angiography revealed attenuation of the retinal vascular plexus with time. CONCLUSION We provide for the first time a detailed long-term analysis of the course of retinal degeneration in P23H rats using a combination of SLO and OCT imaging, angiography, FAF and IHC. Although, the application of noninvasive methods enables longitudinal studies and will decrease the number of animals needed for a study, IHC is still an essential tool to identify retinal changes at the cellular level.
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Macedo B, Millen TA, Braga CACA, Gomes MPB, Ferreira PS, Kraineva J, Winter R, Silva JL, Cordeiro Y. Nonspecific Prion Protein–Nucleic Acid Interactions Lead to Different Aggregates and Cytotoxic Species. Biochemistry 2012; 51:5402-13. [DOI: 10.1021/bi300440e] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Bruno Macedo
- Faculdade de Farmacia, Universidade Federal do Rio de Janeiro, RJ 21941-590,
Rio de Janeiro, Brazil
| | - Thiago A. Millen
- Instituto de Bioquimica Medica, Universidade Federal do Rio de Janeiro, Rio de Janeiro,
Brazil
| | - Carolina A. C. A. Braga
- Instituto de Bioquimica Medica, Universidade Federal do Rio de Janeiro, Rio de Janeiro,
Brazil
| | - Mariana P. B. Gomes
- Faculdade de Farmacia, Universidade Federal do Rio de Janeiro, RJ 21941-590,
Rio de Janeiro, Brazil
| | - Priscila S. Ferreira
- Instituto de Bioquimica Medica, Universidade Federal do Rio de Janeiro, Rio de Janeiro,
Brazil
| | - Julia Kraineva
- Faculty of Chemistry,
Physical
Chemistry I, Dortmund University, Dortmund,
Germany
| | - Roland Winter
- Faculty of Chemistry,
Physical
Chemistry I, Dortmund University, Dortmund,
Germany
| | - Jerson L. Silva
- Instituto de Bioquimica Medica, Universidade Federal do Rio de Janeiro, Rio de Janeiro,
Brazil
| | - Yraima Cordeiro
- Faculdade de Farmacia, Universidade Federal do Rio de Janeiro, RJ 21941-590,
Rio de Janeiro, Brazil
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Liu YH, Han YL, Song J, Wang Y, Jing YY, Shi Q, Tian C, Wang ZY, Li CP, Han J, Dong XP. Heat shock protein 104 inhibited the fibrillization of prion peptide 106–126 and disassembled prion peptide 106–126 fibrils in vitro. Int J Biochem Cell Biol 2011; 43:768-74. [DOI: 10.1016/j.biocel.2011.01.022] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Revised: 01/21/2011] [Accepted: 01/28/2011] [Indexed: 11/30/2022]
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Microcebus murinus retina: a new model to assess prion-related neurotoxicity in primates. Neurobiol Dis 2010; 39:211-20. [PMID: 20399858 DOI: 10.1016/j.nbd.2010.04.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Revised: 04/06/2010] [Accepted: 04/09/2010] [Indexed: 11/28/2022] Open
Abstract
No effective treatment currently exists for prion diseases and therefore the development of experimental non-human primate models of prion neurotoxicity, to better understand the underlying mechanism and to test new treatments relevant to humans, represents an urgent medical need. However, the establishment of such models is challenging due to animal welfare and cost considerations. We describe here the use of Microcebus murinus retina, in primary cultures and in vivo, as a new experimental primate model to rapidly examine the effects in the central nervous system of PrP(106-126), a neurotoxic fragment of the human prion protein. We demonstrate that PrP(106-126) triggered rod photoreceptor cell loss by apoptosis and a change in morphology of microglial cells in mixed neuronal-glial cultures of retinal cells. In addition, 2days after intravitreal injection of PrP(106-126), retinas showed a significant increase in the number of apoptotic nuclei, mainly in the ganglion cell layer.
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Smith JD, Greenlee JJ, Hamir AN. Altered electroretinogram b-wave in a Suffolk sheep experimentally infected with scrapie. Vet Rec 2009; 165:179-81. [DOI: 10.1136/vr.165.6.179] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- J. D. Smith
- Virus and Prion Diseases of Livestock Research Unit; National Animal Disease Center; United States Department of Agriculture; Agricultural Research Service; Ames IA 50010 USA
| | - J. J. Greenlee
- Virus and Prion Diseases of Livestock Research Unit; National Animal Disease Center; United States Department of Agriculture; Agricultural Research Service; Ames IA 50010 USA
| | - A. N. Hamir
- Virus and Prion Diseases of Livestock Research Unit; National Animal Disease Center; United States Department of Agriculture; Agricultural Research Service; Ames IA 50010 USA
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Core structure of amyloid fibrils formed by residues 106-126 of the human prion protein. Structure 2009; 17:417-26. [PMID: 19278656 DOI: 10.1016/j.str.2008.12.018] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Revised: 11/24/2008] [Accepted: 12/21/2008] [Indexed: 11/21/2022]
Abstract
Peptides comprising residues 106-126 of the human prion protein (PrP) exhibit many features of the full-length protein. PrP(106-126) induces apoptosis in neurons, forms fibrillar aggregates, and can mediate the conversion of native cellular PrP (PrP(C)) to the scrapie form (PrP(Sc)). Despite a wide range of biochemical and biophysical studies on this peptide, including investigation of its propensity for aggregation, interactions with cell membranes, and PrP-like toxicity, the structure of amyloid fibrils formed by PrP(106-126) remains poorly defined. In this study we use solid-state nuclear magnetic resonance to define the secondary and quaternary structure of PrP(106-126) fibrils. Our results reveal that PrP(106-126) forms in-register parallel beta sheets, stacked in an antiparallel fashion within the mature fibril. The close intermolecular contacts observed in the fibril core provide a rational for the sequence-dependent behavior of PrP(106-126), and provide a basis for further investigation of its biological properties.
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12
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Lechauve C, Rezaei H, Celier C, Kiger L, Corral-Debrinski M, Noinville S, Chauvierre C, Hamdane D, Pato C, Marden MC. Neuroglobin and prion cellular localization: investigation of a potential interaction. J Mol Biol 2009; 388:968-77. [PMID: 19327369 DOI: 10.1016/j.jmb.2009.03.047] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Revised: 02/18/2009] [Accepted: 03/18/2009] [Indexed: 11/25/2022]
Abstract
Neuroglobin (Ngb) and the cellular prion protein (PrP(c)), proteins of unknown function in the nervous system, are known to be expressed in the retina and have been observed in different rat retinal cells. The retina is the site of the highest concentration for Ngb, a heme protein of similar size and conformation to myoglobin. In this study, we demonstrated by immunohistochemical analysis of retinal colocalization of Ngb and PrP(c) in the ganglion cell layer. Considering for these two a common protective role in relation to oxidative stress and a possible transient contact during migration of PrP(c) through the eye or upon neuronal degradation, we undertook in vitro studies of the interaction of the purified proteins. Mixing these two proteins leads to rapid aggregation, even at submicromolar concentrations. As observed with the use of dynamic light scattering, particles comprising both proteins evolve to hundreds of nanometers within several seconds, a first report showing that PrP(c) is able to form aggregates without major structural changes. The main effect would then appear to be a protein-protein interaction specific to the surface charge of the Ngb protein with PrP(c) N-terminal sequence. A dominant parameter is the solvent ionic force, which can significantly modify the final state of aggregation. PrP(c), normally anchored to the cell membrane, is toxic in the cytoplasm, where Ngb is present; this could suggest an Ngb function of scavenging proteins capable of forming deleterious aggregates considering a charge complementarity in the complex.
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Affiliation(s)
- Christophe Lechauve
- INSERM U779, Universités Paris VI et XI, Hopital de Bicêtre, Le Kremlin-Bicêtre, France
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Barhoum R, Martínez-Navarrete G, Corrochano S, Germain F, Fernandez-Sanchez L, de la Rosa EJ, de la Villa P, Cuenca N. Functional and structural modifications during retinal degeneration in the rd10 mouse. Neuroscience 2008; 155:698-713. [PMID: 18639614 DOI: 10.1016/j.neuroscience.2008.06.042] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2008] [Revised: 06/11/2008] [Accepted: 06/11/2008] [Indexed: 10/21/2022]
Abstract
Mouse models of retinal degeneration are useful tools to study therapeutic approaches for patients affected by hereditary retinal dystrophies. We have studied degeneration in the rd10 mice both by immunocytochemistry and TUNEL-labeling of retinal cells, and through electrophysiological recordings. The cell degeneration in the retina of rd10 mice produced appreciable morphological changes in rod and cone cells by P20. Retinal cell death is clearly observed in the central retina and it peaked at P25 when there were 800 TUNEL-positive cells per mm(2). In the central retina, only one row of photoreceptors remained in the outer nuclear layer by P40 and there was a remarkable deterioration of bipolar cell dendrites postsynaptic to photoreceptors. The axon terminals of bipolar cells also underwent atrophy and the inner retina was subject to further changes, including a reduction and disorganization of AII amacrine cell population. Glutamate sensitivity was tested in rod bipolar cells with the single cell patch-clamp technique in slice preparations, although at P60 no significant differences were observed with age-matched controls. Thus, we conclude that rod and cone degeneration in the rd10 mouse model is followed by deterioration of their postsynaptic cells and the cells in the inner retina. However, the functional preservation of receptors for photoreceptor transmission in bipolar cells may open new therapeutic possibilities.
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Affiliation(s)
- R Barhoum
- Departamento de Fisiología, Universidad de Alcalá, Alcalá de Henares 28871, Spain
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Crozet C, Beranger F, Lehmann S. Cellular pathogenesis in prion diseases. Vet Res 2008; 39:44. [DOI: 10.1051/vetres:2008021] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2007] [Accepted: 04/15/2008] [Indexed: 01/15/2023] Open
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