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Pal S, Udgaonkar JB. Slow Misfolding of a Molten Globule form of a Mutant Prion Protein Variant into a β-rich Dimer. J Mol Biol 2024; 436:168736. [PMID: 39097185 DOI: 10.1016/j.jmb.2024.168736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Revised: 07/13/2024] [Accepted: 07/30/2024] [Indexed: 08/05/2024]
Abstract
Misfolding of the prion protein is linked to multiple neurodegenerative diseases. A better understanding of the process requires the identification and structural characterization of intermediate conformations via which misfolding proceeds. In this study, three conserved aromatic residues (Tyr168, Phe174, and Tyr217) located in the C-terminal domain of mouse PrP (wt moPrP) were mutated to Ala. The resultant mutant protein, 3A moPrP, is shown to adopt a molten globule (MG)-like native conformation. Hydrogen-deuterium exchange studies coupled with mass spectrometry revealed that for 3A moPrP, the free energy gap between the MG-like native conformation and misfolding-prone partially unfolded forms is reduced. Consequently, 3A moPrP misfolds in native conditions even in the absence of salt, unlike wt moPrP, which requires the addition of salt to misfold. 3A moPrP misfolds to a β-rich dimer in the absence of salt, which can rapidly form an oligomer upon the addition of salt. In the presence of salt, 3A moPrP misfolds to a β-rich oligomer about a thousand-fold faster than wt moPrP. Importantly, the misfolded structure of the dimer is similar to that of the salt-induced oligomer. Misfolding to oligomer seems to be induced at the level of the dimeric unit by monomer-monomer association, and the oligomer grows by accretion of misfolded dimeric units. Additionally, it is shown that the conserved aromatic residues collectively stabilize not only monomeric protein, but also the structural core of the β-rich oligomers. Finally, it is also shown that 3A moPrP misfolds much faster to amyloid-fibrils than does the wt protein.
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Affiliation(s)
- Suman Pal
- Indian Institute of Science Education and Research Pune, Pune 411008, India
| | - Jayant B Udgaonkar
- Indian Institute of Science Education and Research Pune, Pune 411008, India.
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Ribes JM, Patel MP, Halim HA, Berretta A, Tooze SA, Klöhn PC. Prion protein conversion at two distinct cellular sites precedes fibrillisation. Nat Commun 2023; 14:8354. [PMID: 38102121 PMCID: PMC10724300 DOI: 10.1038/s41467-023-43961-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 11/24/2023] [Indexed: 12/17/2023] Open
Abstract
The self-templating nature of prions plays a central role in prion pathogenesis and is associated with infectivity and transmissibility. Since propagation of proteopathic seeds has now been acknowledged a principal pathogenic process in many types of dementia, more insight into the molecular mechanism of prion replication is vital to delineate specific and common disease pathways. By employing highly discriminatory anti-PrP antibodies and conversion-tolerant PrP chimera, we here report that de novo PrP conversion and formation of fibril-like PrP aggregates are distinct in mechanistic and kinetic terms. De novo PrP conversion occurs within minutes after infection at two subcellular locations, while fibril-like PrP aggregates are formed exclusively at the plasma membrane, hours after infection. Phenotypically distinct pools of abnormal PrP at perinuclear sites and the plasma membrane show differences in N-terminal processing, aggregation state and fibril formation and are linked by exocytic transport via synaptic and large-dense core vesicles.
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Affiliation(s)
- Juan Manuel Ribes
- Medical Research Council Prion Unit at UCL, Institute of Prion Diseases, University College London, London, W1W 7FF, UK
| | - Mitali P Patel
- Medical Research Council Prion Unit at UCL, Institute of Prion Diseases, University College London, London, W1W 7FF, UK
| | - Hazim A Halim
- Medical Research Council Prion Unit at UCL, Institute of Prion Diseases, University College London, London, W1W 7FF, UK
| | - Antonio Berretta
- Medical Research Council Prion Unit at UCL, Institute of Prion Diseases, University College London, London, W1W 7FF, UK
| | - Sharon A Tooze
- Molecular Cell Biology of Autophagy Laboratory, the Francis Crick Institute, London, NW1 1BF, UK
| | - Peter-Christian Klöhn
- Medical Research Council Prion Unit at UCL, Institute of Prion Diseases, University College London, London, W1W 7FF, UK.
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3
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Pal S, Udgaonkar JB. Mutations of evolutionarily conserved aromatic residues suggest that misfolding of the mouse prion protein may commence in multiple ways. J Neurochem 2023; 167:696-710. [PMID: 37941487 DOI: 10.1111/jnc.16007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 10/25/2023] [Accepted: 10/26/2023] [Indexed: 11/10/2023]
Abstract
The misfolding of the mammalian prion protein from its α-helix rich cellular isoform to its β-sheet rich infectious isoform is associated with several neurodegenerative diseases. The determination of the structural mechanism by which misfolding commences, still remains an unsolved problem. In the current study, native-state hydrogen exchange coupled with mass spectrometry has revealed that the N state of the mouse prion protein (moPrP) at pH 4 is in dynamic equilibrium with multiple partially unfolded forms (PUFs) capable of initiating misfolding. Mutation of three evolutionarily conserved aromatic residues, Tyr168, Phe174, and Tyr217 present at the interface of the β2-α2 loop and the C-terminal end of α3 in the structured C-terminal domain of moPrP significantly destabilize the native state (N) of the protein. They also reduce the free energy differences between the N state and two PUFs identified as PUF1 and PUF2**. It is shown that PUF2** in which the β2-α2 loop and the C-terminal end of α3 are disordered, has the same stability as the previously identified PUF2*, but to have a very different structure. Misfolding can commence from both PUF1 and PUF2**, as it can from PUF2*. Hence, misfolding can commence and proceed in multiple ways from structurally distinct precursor conformations. The increased extents to which PUF1 and PUF2** are populated at equilibrium in the case of the mutant variants, greatly accelerate their misfolding. The results suggest that the three aromatic residues may have been evolutionarily selected to impede the misfolding of moPrP.
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Affiliation(s)
- Suman Pal
- Indian Institute of Science Education and Research Pune, Pune, India
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Hara H, Miyata H, Chida J, Sakaguchi S. Strain-dependent role of copper in prion disease through binding to histidine residues in the N-terminal domain of prion protein. J Neurochem 2023; 167:394-409. [PMID: 37777338 DOI: 10.1111/jnc.15971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 08/28/2023] [Accepted: 09/04/2023] [Indexed: 10/02/2023]
Abstract
The cellular prion protein, PrPC , is a copper-binding protein abundantly expressed in the brain, particularly by neurons, and its conformational conversion into the amyloidogenic isoform, PrPSc , plays a key pathogenic role in prion diseases. However, the role of copper binding to PrPC in prion diseases remains unclear. Here, we fed mice with a low-copper or regular diet and intracerebrally inoculated them with two different mouse-adapted RML scrapie and BSE prions. Mice with a low-copper diet developed disease significantly but only slightly later than those with a regular diet after inoculation with BSE prions, but not with RML prions, suggesting that copper could play a minor role in BSE prion pathogenesis, but not in RML prion pathogenesis. We then generated two lines of transgenic mice expressing mouse PrP with copper-binding histidine (His) residues in the N-terminal domain replaced with alanine residues, termed TgPrP(5H > A)-7342/Prnp0/0 and TgPrP(5H > A)-7524/Prnp0/0 mice, and similarly inoculated RML and BSE prions into them. Due to 2-fold higher expression of PrP(5H > A) than PrPC in wild-type (WT) mice, TgPrP(5H > A)-7524/Prnp0/0 mice were highly susceptible to these prions, compared to WT mice. However, TgPrP(5H > A)-7342/Prnp0/0 mice, which express PrP(5H > A) 1.2-fold as high as PrPC in WT mice, succumbed to disease slightly, but not significantly, later than WT mice after inoculation with RML prions, but significantly so after inoculation with BSE prions. Subsequent secondary inoculation experiments revealed that amino acid sequence differences between PrP(5H > A) and WT PrPSc created no prion transmission barrier to BSE prions. These results suggest that copper-binding His residues in PrPC are dispensable for RML prion pathogenesis but have a minor effect on BSE prion pathogenesis. Taken together, our current results suggest that copper could have a minor effect on prion pathogenesis in a strain-dependent manner through binding to His residues in the N-terminal domain of PrPC .
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Affiliation(s)
- Hideyuki Hara
- Division of Molecular Neurobiology, The Institute for Enzyme Research (KOSOKEN), Tokushima University, Tokushima, Japan
| | - Hironori Miyata
- Animal Research Center, School of Medicine, University of Occupational and Environmental Health, Yahatanishi, Kitakyushu, Japan
| | - Junji Chida
- Division of Molecular Neurobiology, The Institute for Enzyme Research (KOSOKEN), Tokushima University, Tokushima, Japan
| | - Suehiro Sakaguchi
- Division of Molecular Neurobiology, The Institute for Enzyme Research (KOSOKEN), Tokushima University, Tokushima, Japan
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Lawrence JA, Aguilar-Calvo P, Ojeda-Juárez D, Khuu H, Soldau K, Pizzo DP, Wang J, Malik A, Shay TF, Sullivan EE, Aulston B, Song SM, Callender JA, Sanchez H, Geschwind MD, Roy S, Rissman RA, Trejo J, Tanaka N, Wu C, Chen X, Patrick GN, Sigurdson CJ. Diminished Neuronal ESCRT-0 Function Exacerbates AMPA Receptor Derangement and Accelerates Prion-Induced Neurodegeneration. J Neurosci 2023; 43:3970-3984. [PMID: 37019623 PMCID: PMC10219035 DOI: 10.1523/jneurosci.1878-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 03/22/2023] [Accepted: 03/27/2023] [Indexed: 04/07/2023] Open
Abstract
Endolysosomal defects in neurons are central to the pathogenesis of prion and other neurodegenerative disorders. In prion disease, prion oligomers traffic through the multivesicular body (MVB) and are routed for degradation in lysosomes or for release in exosomes, yet how prions impact proteostatic pathways is unclear. We found that prion-affected human and mouse brain showed a marked reduction in Hrs and STAM1 (ESCRT-0), which route ubiquitinated membrane proteins from early endosomes into MVBs. To determine how the reduction in ESCRT-0 impacts prion conversion and cellular toxicity in vivo, we prion-challenged conditional knockout mice (male and female) having Hrs deleted from neurons, astrocytes, or microglia. The neuronal, but not astrocytic or microglial, Hrs-depleted mice showed a shortened survival and an acceleration in synaptic derangements, including an accumulation of ubiquitinated proteins, deregulation of phosphorylated AMPA and metabotropic glutamate receptors, and profoundly altered synaptic structure, all of which occurred later in the prion-infected control mice. Finally, we found that neuronal Hrs (nHrs) depletion increased surface levels of the cellular prion protein, PrPC, which may contribute to the rapidly advancing disease through neurotoxic signaling. Taken together, the reduced Hrs in the prion-affected brain hampers ubiquitinated protein clearance at the synapse, exacerbates postsynaptic glutamate receptor deregulation, and accelerates neurodegeneration.SIGNIFICANCE STATEMENT Prion diseases are rapidly progressive neurodegenerative disorders characterized by prion aggregate spread through the central nervous system. Early disease features include ubiquitinated protein accumulation and synapse loss. Here, we investigate how prion aggregates alter ubiquitinated protein clearance pathways (ESCRT) in mouse and human prion-infected brain, discovering a marked reduction in Hrs. Using a prion-infection mouse model with neuronal Hrs (nHrs) depleted, we show that low neuronal Hrs is detrimental and markedly shortens survival time while accelerating synaptic derangements, including ubiquitinated protein accumulation, indicating that Hrs loss exacerbates prion disease progression. Additionally, Hrs depletion increases the surface distribution of prion protein (PrPC), linked to aggregate-induced neurotoxic signaling, suggesting that Hrs loss in prion disease accelerates disease through enhancing PrPC-mediated neurotoxic signaling.
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Affiliation(s)
- Jessica A Lawrence
- Department of Pathology, University of California, San Diego, La, Jolla, California, 92093
| | - Patricia Aguilar-Calvo
- Department of Pathology, University of California, San Diego, La, Jolla, California, 92093
| | - Daniel Ojeda-Juárez
- Department of Pathology, University of California, San Diego, La, Jolla, California, 92093
| | - Helen Khuu
- Department of Pathology, University of California, San Diego, La, Jolla, California, 92093
| | - Katrin Soldau
- Department of Pathology, University of California, San Diego, La, Jolla, California, 92093
| | - Donald P Pizzo
- Department of Pathology, University of California, San Diego, La, Jolla, California, 92093
| | - Jin Wang
- Department of Pathology, University of California, San Diego, La, Jolla, California, 92093
| | - Adela Malik
- Department of Pathology, University of California, San Diego, La, Jolla, California, 92093
| | - Timothy F Shay
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125
| | - Erin E Sullivan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125
| | - Brent Aulston
- Department of Neurosciences, University of California, San Diego, La Jolla, California 92093
| | - Seung Min Song
- Department of Pathology, University of California, San Diego, La, Jolla, California, 92093
| | - Julia A Callender
- Department of Pathology, University of California, San Diego, La, Jolla, California, 92093
| | - Henry Sanchez
- Department of Pathology, University of California, San Francisco, San Francisco, California 94143
| | - Michael D Geschwind
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California 94143
| | - Subhojit Roy
- Department of Pathology, University of California, San Diego, La, Jolla, California, 92093
- Department of Neurosciences, University of California, San Diego, La Jolla, California 92093
| | - Robert A Rissman
- Department of Neurosciences, University of California, San Diego, La Jolla, California 92093
| | - JoAnn Trejo
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093
| | - Nobuyuki Tanaka
- Division of Tumor Immunobiology, Miyagi Cancer Center Research Institute, Natori 981-1293, Japan
- Division of Tumor Immunobiology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Chengbiao Wu
- Department of Neurosciences, University of California, San Diego, La Jolla, California 92093
| | - Xu Chen
- Department of Neurosciences, University of California, San Diego, La Jolla, California 92093
| | - Gentry N Patrick
- Department of Biology, University of California, San Diego, La Jolla, California 92093
| | - Christina J Sigurdson
- Department of Pathology, University of California, San Diego, La, Jolla, California, 92093
- Department of Pathology, Microbiology, and Immunology, University of California, Davis, Davis, California 95616
- Department of Medicine, University of California, San Diego, La Jolla, California 92093
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Loss of small GTPase Rab7 activation in prion infection negatively affects a feedback loop regulating neuronal cholesterol metabolism. J Biol Chem 2023; 299:102883. [PMID: 36623732 PMCID: PMC9926124 DOI: 10.1016/j.jbc.2023.102883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 12/11/2022] [Accepted: 12/14/2022] [Indexed: 01/09/2023] Open
Abstract
Prion diseases are fatal and infectious neurodegenerative diseases that occur in humans and animals. They are caused by the misfolding of the cellular prion protein PrPc into the infectious isoform PrPSc. PrPSc accumulates mostly in endolysosomal vesicles of prion-infected cells, eventually causing neurodegeneration. In response to prion infection, elevated cholesterol levels and a reduction in membrane-attached small GTPase Rab7 have been observed in neuronal cells. Here, we investigated the molecular events causing an impaired Rab7 membrane attachment and the potential mechanistic link with elevated cholesterol levels in prion infection. We demonstrate that prion infection is associated with reduced levels of active Rab7 (Rab7.GTP) in persistently prion-infected neuronal cell lines, primary cerebellar granular neurons, and neurons in the brain of mice with terminal prion disease. In primary cerebellar granular neurons, levels of active Rab7 were increased during the very early stages of the prion infection prior to a significant decrease concomitant with PrPSc accumulation. The reduced activation of Rab7 in prion-infected neuronal cell lines is also associated with its reduced ubiquitination status, decreased interaction with its effector RILP, and altered lysosomal positioning. Consequently, the Rab7-mediated trafficking of low-density lipoprotein to lysosomes is delayed. This results in an impaired feedback regulation of cholesterol synthesis leading to an increase in cholesterol levels. Notably, transient overexpression of the constitutively active mutant of Rab7 rescues the delay in the low-density lipoprotein trafficking, hence reducing cholesterol levels and attenuating PrPSc propagation, demonstrating a mechanistic link between the loss of Rab7.GTP and elevated cholesterol levels.
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Noori L, Filip K, Nazmara Z, Mahakizadeh S, Hassanzadeh G, Caruso Bavisotto C, Bucchieri F, Marino Gammazza A, Cappello F, Wnuk M, Scalia F. Contribution of Extracellular Vesicles and Molecular Chaperones in Age-Related Neurodegenerative Disorders of the CNS. Int J Mol Sci 2023; 24:ijms24020927. [PMID: 36674442 PMCID: PMC9861359 DOI: 10.3390/ijms24020927] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/22/2022] [Accepted: 12/30/2022] [Indexed: 01/06/2023] Open
Abstract
Many neurodegenerative disorders are characterized by the abnormal aggregation of misfolded proteins that form amyloid deposits which possess prion-like behavior such as self-replication, intercellular transmission, and consequent induction of native forms of the same protein in surrounding cells. The distribution of the accumulated proteins and their correlated toxicity seem to be involved in the progression of nervous system degeneration. Molecular chaperones are known to maintain proteostasis, contribute to protein refolding to protect their function, and eliminate fatally misfolded proteins, prohibiting harmful effects. However, chaperone network efficiency declines during aging, prompting the onset and the development of neurological disorders. Extracellular vesicles (EVs) are tiny membranous structures produced by a wide range of cells under physiological and pathological conditions, suggesting their significant role in fundamental processes particularly in cellular communication. They modulate the behavior of nearby and distant cells through their biological cargo. In the pathological context, EVs transport disease-causing entities, including prions, α-syn, and tau, helping to spread damage to non-affected areas and accelerating the progression of neurodegeneration. However, EVs are considered effective for delivering therapeutic factors to the nervous system, since they are capable of crossing the blood-brain barrier (BBB) and are involved in the transportation of a variety of cellular entities. Here, we review the neurodegeneration process caused mainly by the inefficiency of chaperone systems as well as EV performance in neuropathies, their potential as diagnostic biomarkers and a promising EV-based therapeutic approach.
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Affiliation(s)
- Leila Noori
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90127 Palermo, Italy
- Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran 1417653761, Iran
| | - Kamila Filip
- Department of Biology, Institute of Biology and Biotechnology, College of Natural Sciences, University of Rzeszow, 35959 Rzeszow, Poland
| | - Zohreh Nazmara
- Department of Neuroscience and Addiction Studies, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran 1417653761, Iran
| | - Simin Mahakizadeh
- Department of Anatomy, School of Medicine, Alborz University of Medical Sciences, Karaj 3149779453, Iran
| | - Gholamreza Hassanzadeh
- Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran 1417653761, Iran
- Department of Neuroscience and Addiction Studies, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran 1417653761, Iran
| | - Celeste Caruso Bavisotto
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90127 Palermo, Italy
- Euro-Mediterranean Institute of Science and Technology (IEMEST), 90139 Palermo, Italy
- Correspondence: (C.C.B.); (F.S.)
| | - Fabio Bucchieri
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90127 Palermo, Italy
| | - Antonella Marino Gammazza
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90127 Palermo, Italy
| | - Francesco Cappello
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90127 Palermo, Italy
- Euro-Mediterranean Institute of Science and Technology (IEMEST), 90139 Palermo, Italy
| | - Maciej Wnuk
- Department of Biotechnology, Institute of Biology and Biotechnology, College of Natural Sciences, University of Rzeszow, 35959 Rzeszow, Poland
| | - Federica Scalia
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90127 Palermo, Italy
- Euro-Mediterranean Institute of Science and Technology (IEMEST), 90139 Palermo, Italy
- Correspondence: (C.C.B.); (F.S.)
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Pal S, Udgaonkar JB. Evolutionarily Conserved Proline Residues Impede the Misfolding of the Mouse Prion Protein by Destabilizing an Aggregation-competent Partially Unfolded Form. J Mol Biol 2022; 434:167854. [PMID: 36228749 DOI: 10.1016/j.jmb.2022.167854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 10/04/2022] [Accepted: 10/04/2022] [Indexed: 11/06/2022]
Abstract
The misfolding of the prion protein has been linked to several neurodegenerative diseases. Despite extensive studies, the mechanism of the misfolding process remains poorly understood. The present study structurally delineates the role of the conserved proline residues present in the structured C-terminal domain of the mouse prion protein (moPrP) in the misfolding process. It is shown that mutation of these Pro residues to Ala leads to destabilization of the native (N) state, and also to rapid misfolding. Using hydrogen-deuterium exchange (HDX) studies coupled with mass spectrometry (MS), it has been shown that the N state of moPrP is in rapid equilibrium with a partially unfolded form (PUF2*) at pH 4. It has been shown that the Pro to Ala mutations make PUF2* energetically more accessible from the N state by stabilizing it relative to the unfolded (U) state. The apparent rate constant of misfolding is found to be linearly proportional to the extent to which PUF2* is populated in equilibrium with the N state, strongly indicating that misfolding commences from PUF2*. It has also been shown that the Pro residues restrict the boundary of the structural core of the misfolded oligomers. Overall, this study highlights how the conserved proline residues control misfolding of the prion protein by modulating the stability of the partially unfolded form from which misfolding commences.
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Affiliation(s)
- Suman Pal
- Indian Institute of Science Education and Research, Pune, India
| | - Jayant B Udgaonkar
- Indian Institute of Science Education and Research, Pune, India; National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru, India.
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Dar GH, Badierah R, Nathan EG, Bhat MA, Dar AH, Redwan EM. Extracellular vesicles: A new paradigm in understanding, diagnosing and treating neurodegenerative disease. Front Aging Neurosci 2022; 14:967231. [PMID: 36408114 PMCID: PMC9669424 DOI: 10.3389/fnagi.2022.967231] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 09/29/2022] [Indexed: 08/27/2023] Open
Abstract
Neurodegenerative disorders (NDs) are becoming one of the leading causes of disability and death across the globe due to lack of timely preventions and treatments. Concurrently, intensive research efforts are being carried out to understand the etiology of these age-dependent disorders. Extracellular vesicles (EVs)-biological nanoparticles released by cells-are gaining tremendous attention in understanding their role in pathogenesis and progression of NDs. EVs have been found to transmit pathogenic proteins of NDs between neurons. Moreover, the ability of EVs to exquisitely surmount natural biological barriers, including blood-brain barrier and in vivo safety has generated interest in exploring them as potential biomarkers and function as natural delivery vehicles of drugs to the central nervous system. However, limited knowledge of EV biogenesis, their heterogeneity and lack of adequate isolation and analysis tools have hampered their therapeutic potential. In this review, we cover the recent advances in understanding the role of EVs in neurodegeneration and address their role as biomarkers and delivery vehicles to the brain.
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Affiliation(s)
- Ghulam Hassan Dar
- Department of Biochemistry, S.P. College, Cluster University Srinagar, Srinagar, India
- Hassan Khoyihami Memorial Degree College, Bandipora, India
| | - Raied Badierah
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
- Medical Laboratory, King Abdulaziz University Hospital, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Erica G. Nathan
- Department of Oncology, Cambridge Cancer Center, Cambridge, United Kingdom
| | | | - Abid Hamid Dar
- Department of Biotechnology, School of Life Sciences, Central University of Kashmir, Ganderbal, India
| | - Elrashdy M. Redwan
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
- Protein Research Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), The City of Scientific Research and Technological Applications (SRTA-City), Alexandria, Egypt
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Artikis E, Kraus A, Caughey B. Structural biology of ex vivo mammalian prions. J Biol Chem 2022; 298:102181. [PMID: 35752366 PMCID: PMC9293645 DOI: 10.1016/j.jbc.2022.102181] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/16/2022] [Accepted: 06/19/2022] [Indexed: 01/13/2023] Open
Abstract
The structures of prion protein (PrP)–based mammalian prions have long been elusive. However, cryo-EM has begun to reveal the near-atomic resolution structures of fully infectious ex vivo mammalian prion fibrils as well as relatively innocuous synthetic PrP amyloids. Comparisons of these various types of PrP fibrils are now providing initial clues to structural features that correlate with pathogenicity. As first indicated by electron paramagnetic resonance and solid-state NMR studies of synthetic amyloids, all sufficiently resolved PrP fibrils of any sort (n > 10) have parallel in-register intermolecular β-stack architectures. Cryo-EM has shown that infectious brain-derived prion fibrils of the rodent-adapted 263K and RML scrapie strains have much larger ordered cores than the synthetic fibrils. These bona fide prion strains share major structural motifs, but the conformational details and the overall shape of the fibril cross sections differ markedly. Such motif variations, as well as differences in sequence within the ordered polypeptide cores, likely contribute to strain-dependent templating. When present, N-linked glycans and glycophosphatidylinositol (GPI) anchors project outward from the fibril surface. For the mouse RML strain, these posttranslational modifications have little effect on the core structure. In the GPI-anchored prion structures, a linear array of GPI anchors along the twisting fibril axis appears likely to bind membranes in vivo, and as such, may account for pathognomonic membrane distortions seen in prion diseases. In this review, we focus on these infectious prion structures and their implications regarding prion replication mechanisms, strains, transmission barriers, and molecular pathogenesis.
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Affiliation(s)
- Efrosini Artikis
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840 USA
| | - Allison Kraus
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
| | - Byron Caughey
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840 USA.
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Thackray AM, Lam B, McNulty EE, Nalls AV, Mathiason CK, Magadi SS, Jackson WS, Andréoletti O, Marrero-Winkens C, Schätzl H, Bujdoso R. Clearance of variant Creutzfeldt-Jakob disease prions in vivo by the Hsp70 disaggregase system. Brain 2022; 145:3236-3249. [PMID: 35446941 PMCID: PMC9473358 DOI: 10.1093/brain/awac144] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/10/2022] [Accepted: 03/30/2022] [Indexed: 11/13/2022] Open
Abstract
The metazoan Hsp70 disaggregase protects neurons from proteotoxicity that arises from the accumulation of misfolded protein aggregates. Hsp70 and its co-chaperones disassemble and extract polypeptides from protein aggregates for refolding or degradation. The effectiveness of the chaperone system decreases with age and leads to accumulation rather than removal of neurotoxic protein aggregates. Therapeutic enhancement of the Hsp70 protein disassembly machinery is proposed to counter late-onset protein misfolding neurodegenerative disease that may arise. In the context of prion disease, it is not known whether stimulation of protein aggregate disassembly paradoxically leads to enhanced formation of seeding competent species of disease-specific proteins and acceleration of neurodegenerative disease. Here we have tested the hypothesis that modulation of Hsp70 disaggregase activity perturbs mammalian prion-induced neurotoxicity and prion seeding activity. To do so we used prion protein (PrP) transgenic Drosophila that authentically replicate mammalian prions. RNASeq identified that Hsp70, DnaJ-1 and Hsp110 gene expression was downregulated in prion-exposed PrP Drosophila. We demonstrated that RNAi knockdown of Hsp110 or DnaJ-1 gene expression in variant Creutzfeldt–Jakob disease prion-exposed human PrP Drosophila enhanced neurotoxicity, whereas overexpression mitigated toxicity. Strikingly, prion seeding activity in variant Creutzfeldt–Jakob disease prion-exposed human PrP Drosophila was ablated or reduced by Hsp110 or DnaJ-1 overexpression, respectively. Similar effects were seen in scrapie prion-exposed ovine PrP Drosophila with modified Hsp110 or DnaJ-1 gene expression. These unique observations show that the metazoan Hsp70 disaggregase facilitates the clearance of mammalian prions and that its enhanced activity is a potential therapeutic strategy for human prion disease.
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Affiliation(s)
- Alana M Thackray
- University of Cambridge, Department of Veterinary Medicine, Madingley Road, Cambridge, CB3 0ES, UK
| | - Brian Lam
- Medical Research Council Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science-Metabolic Research Laboratories, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Erin E McNulty
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Amy V Nalls
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Candace K Mathiason
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Srivathsa Subramanya Magadi
- Wallenberg Center for Molecular Medicine, Department of Clinical and Experimental Medicine, Linköping University, 581 83 Linköping, Sweden
| | - Walker S Jackson
- Wallenberg Center for Molecular Medicine, Department of Clinical and Experimental Medicine, Linköping University, 581 83 Linköping, Sweden
| | - Olivier Andréoletti
- UMR INRA ENVT 1225 -Hôtes-Agents Pathogènes, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, 31076 Toulouse, France
| | - Cristóbal Marrero-Winkens
- Calgary Prion Research Unit, Faculty of Veterinary Medicine, University of Calgary TRW 2D10, 3280 Hospital Drive NW, Calgary, AB, Canada T2N 4Z6
| | - Hermann Schätzl
- Calgary Prion Research Unit, Faculty of Veterinary Medicine, University of Calgary TRW 2D10, 3280 Hospital Drive NW, Calgary, AB, Canada T2N 4Z6
| | - Raymond Bujdoso
- University of Cambridge, Department of Veterinary Medicine, Madingley Road, Cambridge, CB3 0ES, UK
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12
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Heumüller SE, Hornberger AC, Hebestreit AS, Hossinger A, Vorberg IM. Propagation and Dissemination Strategies of Transmissible Spongiform Encephalopathy Agents in Mammalian Cells. Int J Mol Sci 2022; 23:ijms23062909. [PMID: 35328330 PMCID: PMC8949484 DOI: 10.3390/ijms23062909] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/25/2022] [Accepted: 03/01/2022] [Indexed: 01/08/2023] Open
Abstract
Transmissible spongiform encephalopathies or prion disorders are fatal infectious diseases that cause characteristic spongiform degeneration in the central nervous system. The causative agent, the so-called prion, is an unconventional infectious agent that propagates by converting the host-encoded cellular prion protein PrP into ordered protein aggregates with infectious properties. Prions are devoid of coding nucleic acid and thus rely on the host cell machinery for propagation. While it is now established that, in addition to PrP, other cellular factors or processes determine the susceptibility of cell lines to prion infection, exact factors and cellular processes remain broadly obscure. Still, cellular models have uncovered important aspects of prion propagation and revealed intercellular dissemination strategies shared with other intracellular pathogens. Here, we summarize what we learned about the processes of prion invasion, intracellular replication and subsequent dissemination from ex vivo cell models.
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Affiliation(s)
- Stefanie-Elisabeth Heumüller
- Laboratory of Prion Cell Biology, German Center for Neurodegenerative Diseases Bonn (DZNE e.V.), Venusberg-Campus 1/99, 53127 Bonn, Germany; (S.-E.H.); (A.C.H.); (A.S.H.); (A.H.)
| | - Annika C. Hornberger
- Laboratory of Prion Cell Biology, German Center for Neurodegenerative Diseases Bonn (DZNE e.V.), Venusberg-Campus 1/99, 53127 Bonn, Germany; (S.-E.H.); (A.C.H.); (A.S.H.); (A.H.)
| | - Alina S. Hebestreit
- Laboratory of Prion Cell Biology, German Center for Neurodegenerative Diseases Bonn (DZNE e.V.), Venusberg-Campus 1/99, 53127 Bonn, Germany; (S.-E.H.); (A.C.H.); (A.S.H.); (A.H.)
| | - André Hossinger
- Laboratory of Prion Cell Biology, German Center for Neurodegenerative Diseases Bonn (DZNE e.V.), Venusberg-Campus 1/99, 53127 Bonn, Germany; (S.-E.H.); (A.C.H.); (A.S.H.); (A.H.)
| | - Ina M. Vorberg
- Laboratory of Prion Cell Biology, German Center for Neurodegenerative Diseases Bonn (DZNE e.V.), Venusberg-Campus 1/99, 53127 Bonn, Germany; (S.-E.H.); (A.C.H.); (A.S.H.); (A.H.)
- German Center for Neurodegenerative Diseases (DZNE), Rheinische Friedrich-Wilhelms-Universität Bonn, Siegmund-Freud-Str. 25, 53127 Bonn, Germany
- Correspondence:
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13
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Russo L, Salzano G, Corvino A, Bistaffa E, Moda F, Celauro L, D'Abrosca G, Isernia C, Milardi D, Giachin G, Malgieri G, Legname G, Fattorusso R. Structural and dynamical determinants of a β-sheet-enriched intermediate involved in amyloid fibrillar assembly of human prion protein. Chem Sci 2022; 13:10406-10427. [PMID: 36277622 PMCID: PMC9473526 DOI: 10.1039/d2sc00345g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 08/04/2022] [Indexed: 12/02/2022] Open
Abstract
The conformational conversion of the cellular prion protein (PrPC) into a misfolded, aggregated and infectious scrapie isoform is associated with prion disease pathology and neurodegeneration. Despite the significant number of experimental and theoretical studies the molecular mechanism regulating this structural transition is still poorly understood. Here, via Nuclear Magnetic Resonance (NMR) methodologies we investigate at the atomic level the mechanism of the human HuPrP(90–231) thermal unfolding and characterize the conformational equilibrium between its native structure and a β-enriched intermediate state, named β-PrPI. By comparing the folding mechanisms of metal-free and Cu2+-bound HuPrP(23–231) and HuPrP(90–231) we show that the coupling between the N- and C-terminal domains, through transient electrostatic interactions, is the key molecular process in tuning long-range correlated μs–ms dynamics that in turn modulate the folding process. Moreover, via thioflavin T (ThT)-fluorescence fibrillization assays we show that β-PrPI is involved in the initial stages of PrP fibrillation, overall providing a clear molecular description of the initial phases of prion misfolding. Finally, we show by using Real-Time Quaking-Induced Conversion (RT-QuIC) that the β-PrPI acts as a seed for the formation of amyloid aggregates with a seeding activity comparable to that of human infectious prions. The N-ter domain in HuPrP regulates the folding mechanism by tuning the long-range μs–ms dynamics. Removal of the N-ter domain triggers the formation of a stable β-enriched intermediate state inducing amyloid aggregates with HuPrPSc seeding activity.![]()
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Affiliation(s)
- Luigi Russo
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania Luigi Vanvitelli, Caserta, Italy
| | - Giulia Salzano
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
| | - Andrea Corvino
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania Luigi Vanvitelli, Caserta, Italy
| | - Edoardo Bistaffa
- Fondazione IRCCS Istituto Neurologico Carlo Besta, Division of Neurology 5 and Neuropathology, Milano, Italy
| | - Fabio Moda
- Fondazione IRCCS Istituto Neurologico Carlo Besta, Division of Neurology 5 and Neuropathology, Milano, Italy
| | - Luigi Celauro
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
| | - Gianluca D'Abrosca
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania Luigi Vanvitelli, Caserta, Italy
| | - Carla Isernia
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania Luigi Vanvitelli, Caserta, Italy
| | - Danilo Milardi
- Institute of Crystallography, National Research Council, Catania, Italy
| | - Gabriele Giachin
- Department of Chemical Sciences (DiSC), University of Padua, Padova, Italy
| | - Gaetano Malgieri
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania Luigi Vanvitelli, Caserta, Italy
| | - Giuseppe Legname
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
- ELETTRA Laboratory, Sincrotrone Trieste S.C.p.A., Basovizza, Trieste, Italy
| | - Roberto Fattorusso
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania Luigi Vanvitelli, Caserta, Italy
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14
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Chassefeyre R, Chaiamarit T, Verhelle A, Novak SW, Andrade LR, Leitão ADG, Manor U, Encalada SE. Endosomal sorting drives the formation of axonal prion protein endoggresomes. SCIENCE ADVANCES 2021; 7:eabg3693. [PMID: 34936461 PMCID: PMC8694590 DOI: 10.1126/sciadv.abg3693] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 11/05/2021] [Indexed: 05/15/2023]
Abstract
The pathogenic aggregation of misfolded prion protein (PrP) in axons underlies prion disease pathologies. The molecular mechanisms driving axonal misfolded PrP aggregate formation leading to neurotoxicity are unknown. We found that the small endolysosomal guanosine triphosphatase (GTPase) Arl8b recruits kinesin-1 and Vps41 (HOPS) onto endosomes carrying misfolded mutant PrP to promote their axonal entry and homotypic fusion toward aggregation inside enlarged endomembranes that we call endoggresomes. This axonal rapid endosomal sorting and transport-dependent aggregation (ARESTA) mechanism forms pathologic PrP endoggresomes that impair calcium dynamics and reduce neuronal viability. Inhibiting ARESTA diminishes endoggresome formation, rescues calcium influx, and prevents neuronal death. Our results identify ARESTA as a key pathway for the regulation of endoggresome formation and a new actionable antiaggregation target to ameliorate neuronal dysfunction in the prionopathies.
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Affiliation(s)
- Romain Chassefeyre
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
- Neurodegeneration New Medicines Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Tai Chaiamarit
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
- Neurodegeneration New Medicines Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Adriaan Verhelle
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
- Neurodegeneration New Medicines Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Sammy Weiser Novak
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Leonardo R. Andrade
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - André D. G. Leitão
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
- Neurodegeneration New Medicines Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Uri Manor
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Sandra E. Encalada
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
- Neurodegeneration New Medicines Center, The Scripps Research Institute, La Jolla, CA 92037, USA
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15
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Bhate SH, Udgaonkar JB, Das R. Destabilization of polar interactions in the prion protein triggers misfolding and oligomerization. Protein Sci 2021; 30:2258-2271. [PMID: 34558139 DOI: 10.1002/pro.4188] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 09/15/2021] [Accepted: 09/16/2021] [Indexed: 12/25/2022]
Abstract
The prion protein (PrP) misfolds and oligomerizes at pH 4 in the presence of physiological salt concentrations. Low pH and salt cause structural perturbations in the monomeric prion protein that lead to misfolding and oligomerization. However, the changes in stability within different regions of the PrP prior to oligomerization are poorly understood. In this study, we have characterized the local stability in PrP at high resolution using amide temperature coefficients (TC ) measured by nuclear magnetic resonance (NMR) spectroscopy. The local stability of PrP was investigated under native as well as oligomerizing conditions. We have also studied the rapidly oligomerizing PrP variant (Q216R) and the protective PrP variant (A6). We report that at low pH, salt destabilizes PrP at several polar residues, and the hydrogen bonds in helices α2 and α3 are weakened. In addition, salt changes the curvature of the α3 helix, which likely disrupts α2-α3 contacts and leads to oligomerization. These results are corroborated by the TC values of rapidly oligomerizing Q216R-PrP. The poly-alanine substitution in A6-PrP stabilizes α2, which prevents oligomerization. Altogether, these results highlight the importance of native polar interactions in determining the stability of PrP and reveal the structural disruptions in PrP that lead to misfolding and oligomerization.
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Affiliation(s)
- Suhas H Bhate
- National Centre for Biological Sciences, TIFR, Bangalore, India
| | - Jayant B Udgaonkar
- National Centre for Biological Sciences, TIFR, Bangalore, India.,Indian Institute for Science Education and Research, Pune, India
| | - Ranabir Das
- National Centre for Biological Sciences, TIFR, Bangalore, India
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16
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Patni D, Jha SK. Protonation-Deprotonation Switch Controls the Amyloid-like Misfolding of Nucleic-Acid-Binding Domains of TDP-43. J Phys Chem B 2021; 125:8383-8394. [PMID: 34318672 DOI: 10.1021/acs.jpcb.1c03262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Nutrient starvation stress acidifies the cytosol and leads to the formation of large protein assemblies and misfolded aggregates. However, how starvation stress is sensed at the molecular level and leads to protein misfolding is poorly understood. TDP-43 is a vital protein, which, under stress-like conditions, associates with stress granule proteins via its functional nucleic-acid-binding domains (TDP-43tRRM) and misfolds to form aberrant aggregates. Here, we show that the monomeric N form of TDP-43tRRM forms a misfolded amyloid-like protein assembly, β form, in a pH-dependent manner and identified the critical protein side-chain residue whose protonation triggers its misfolding. We systematically mutated the three buried ionizable residues, D105, H166, and H256, to neutral amino acids to block the pH-dependent protonation-deprotonation titration of their side chain and studied their effect on the N-to-β transition. We observed that D105A and H256Q resembled TDP-43tRRM in their pH-dependent misfolding behavior. However, H166Q retains the N-like secondary structure under low-pH conditions and does not show pH-dependent misfolding to the β form. These results indicate that H166 is the critical side-chain residue whose protonation triggers the misfolding of TDP-43tRRM and shed light on how stress-induced misfolding of proteins during neurodegeneration could begin from site-specific triggers.
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Affiliation(s)
- Divya Patni
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Santosh Kumar Jha
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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17
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Abstract
Introduction: Prion diseases are a class of rare and fatal neurodegenerative diseases for which no cure is currently available. They are characterized by conformational conversion of cellular prion protein (PrPC) into the disease-associated 'scrapie' isoform (PrPSc). Under an etiological point of view, prion diseases can be divided into acquired, genetic, and idiopathic form, the latter of which are the most frequent.Areas covered: Therapeutic approaches targeting prion diseases are based on the use of chemical and nature-based compounds, targeting either PrPC or PrPSc or other putative player in pathogenic mechanism. Other proposed anti-prion treatments include passive and active immunization strategies, peptides, aptamers, and PrPC-directed RNA interference techniques. The treatment efficacy has been mainly assessed in cell lines or animal models of the disease testing their ability to reduce prion accumulation.Expert opinion: The assessed strategies focussing on the identification of an efficient anti-prion therapy faced various issues, which go from permeation of the blood brain barrier to immunological tolerance of the host. Indeed, the use of combinatory approaches, which could boost a synergistic anti-prion effect and lower the potential side effects of single treatments and may represent an extreme powerful and feasible way to tackle prion disease.
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Affiliation(s)
- Marco Zattoni
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore Di Studi Avanzati (SISSA), Trieste, Italy
| | - Giuseppe Legname
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore Di Studi Avanzati (SISSA), Trieste, Italy
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18
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Hackl S, Ng XW, Lu D, Wohland T, Becker CFW. Cytoskeleton-dependent clustering of membrane-bound prion protein on the cell surface. J Biol Chem 2021; 296:100359. [PMID: 33539927 PMCID: PMC7988330 DOI: 10.1016/j.jbc.2021.100359] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 01/26/2021] [Accepted: 01/28/2021] [Indexed: 12/23/2022] Open
Abstract
Prion diseases are a group of neurodegenerative disorders that infect animals and humans with proteinaceous particles called prions. Prions consist of scrapie prion protein (PrPSc), a misfolded version of the cellular prion protein (PrPC). During disease progression, PrPSc replicates by interacting with PrPC and inducing its conversion to PrPSc. Attachment of PrPC to cellular membranes via a glycosylphosphatidylinositol (GPI) anchor is critical for the conversion of PrPC into PrPSc. However, the mechanisms governing PrPC conversion and replication on the membrane remain largely unclear. Here, a site-selectively modified PrP variant equipped with a fluorescent GPI anchor mimic (PrP-GPI) was employed to directly observe PrP at the cellular membrane in neuronal SH-SY5Y cells. PrP-GPI exhibits a cholesterol-dependent membrane accumulation and a cytoskeleton-dependent mobility. More specifically, inhibition of actin polymerization reduced the diffusion of PrP-GPI indicating protein clustering, which resembles the initial step of PrP aggregation and conversion into its pathogenic isoform. An intact actin cytoskeleton might therefore prevent conversion of PrPC into PrPSc and offer new therapeutic angles.
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Affiliation(s)
- Stefanie Hackl
- Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria
| | - Xue Wen Ng
- Departments of Biological Sciences and Chemistry and Centre for Bioimaging Sciences (CBIS), National University of Singapore (NUS), Singapore
| | - Danqin Lu
- Departments of Biological Sciences and Chemistry and Centre for Bioimaging Sciences (CBIS), National University of Singapore (NUS), Singapore; School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China
| | - Thorsten Wohland
- Departments of Biological Sciences and Chemistry and Centre for Bioimaging Sciences (CBIS), National University of Singapore (NUS), Singapore
| | - Christian F W Becker
- Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria.
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19
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Di Natale C, Natale CF, Florio D, Netti PA, Morelli G, Ventre M, Marasco D. Effects of surface nanopatterning on internalization and amyloid aggregation of the fragment 264-277 of Nucleophosmin 1. Colloids Surf B Biointerfaces 2020; 197:111439. [PMID: 33137636 DOI: 10.1016/j.colsurfb.2020.111439] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/06/2020] [Accepted: 10/20/2020] [Indexed: 12/17/2022]
Abstract
The mechanical interpretation of the plethora of factors that governs cellular localization of amyloid aggregates is crucial for planning novel therapeutical interventions in neurodegenerative diseases since these aggregates exert a primary role in the proteostasis machinery. The uptake of Cell Penetrating Peptides (CPPs) conjugated with different amyloid polypeptides occurs via different endocytic processes regulated by cytoskeleton organization and cell morphology. Herein, we deepened the internalization of an amyloid system in cells cultured on nanopatterned surfaces that represent a powerful tool to shape cell and regulate its contractility. We analyzed the behavior of an amyloid model system, employing NPM1264-277 sequence, covalently conjugated to Tat fragment 48-60 as CPP. To investigate its internalization mechanism, we followed the formation of aggregates on two kinds of substrates: a flat and a nanopatterned surface. Herein, investigations during time were carried out by employing both confocal and second harmonic generation (SHG) microscopies. We showed that modifications of cellular environment affect peptide localization, its cytoplasmic translocation and the size of amyloid aggregates.
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Affiliation(s)
- Concetta Di Natale
- Department of Pharmacy, University of Naples "Federico II", Italy; Center for Advanced Biomaterial for Health Care (CABHC), Istituto Italiano di Tecnologia, Naples, Italy; Interdisciplinary Research Centre on Biomaterials (CRIB), University of Naples Federico II, Piazzale Tecchio 80, 80125 Naples, Italy
| | - Carlo F Natale
- Interdisciplinary Research Centre on Biomaterials (CRIB), University of Naples Federico II, Piazzale Tecchio 80, 80125 Naples, Italy
| | - Daniele Florio
- Department of Pharmacy, University of Naples "Federico II", Italy
| | - Paolo Antonio Netti
- Center for Advanced Biomaterial for Health Care (CABHC), Istituto Italiano di Tecnologia, Naples, Italy; Interdisciplinary Research Centre on Biomaterials (CRIB), University of Naples Federico II, Piazzale Tecchio 80, 80125 Naples, Italy; Department of Chemical, Materials and Industrial Production Engineering (DICMAPI), University of Naples Federico II, Piazzale Tecchio 80, 80125 Naples, Italy
| | | | - Maurizio Ventre
- Center for Advanced Biomaterial for Health Care (CABHC), Istituto Italiano di Tecnologia, Naples, Italy; Interdisciplinary Research Centre on Biomaterials (CRIB), University of Naples Federico II, Piazzale Tecchio 80, 80125 Naples, Italy; Department of Chemical, Materials and Industrial Production Engineering (DICMAPI), University of Naples Federico II, Piazzale Tecchio 80, 80125 Naples, Italy
| | - Daniela Marasco
- Department of Pharmacy, University of Naples "Federico II", Italy
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20
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A New Take on Prion Protein Dynamics in Cellular Trafficking. Int J Mol Sci 2020; 21:ijms21207763. [PMID: 33092231 PMCID: PMC7589859 DOI: 10.3390/ijms21207763] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 10/14/2020] [Accepted: 10/14/2020] [Indexed: 12/12/2022] Open
Abstract
The mobility of cellular prion protein (PrPC) in specific cell membrane domains and among distinct cell compartments dictates its molecular interactions and directs its cell function. PrPC works in concert with several partners to organize signaling platforms implicated in various cellular processes. The scaffold property of PrPC is able to gather a molecular repertoire to create heterogeneous membrane domains that favor endocytic events. Dynamic trafficking of PrPC through multiple pathways, in a well-orchestrated mechanism of intra and extracellular vesicular transport, defines its functional plasticity, and also assists the conversion and spreading of its infectious isoform associated with neurodegenerative diseases. In this review, we highlight how PrPC traffics across intra- and extracellular compartments and the consequences of this dynamic transport in governing cell functions and contributing to prion disease pathogenesis.
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21
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Tittelmeier J, Nachman E, Nussbaum-Krammer C. Molecular Chaperones: A Double-Edged Sword in Neurodegenerative Diseases. Front Aging Neurosci 2020; 12:581374. [PMID: 33132902 PMCID: PMC7572858 DOI: 10.3389/fnagi.2020.581374] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 09/09/2020] [Indexed: 12/16/2022] Open
Abstract
Aberrant accumulation of misfolded proteins into amyloid deposits is a hallmark in many age-related neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), and amyotrophic lateral sclerosis (ALS). Pathological inclusions and the associated toxicity appear to spread through the nervous system in a characteristic pattern during the disease. This has been attributed to a prion-like behavior of amyloid-type aggregates, which involves self-replication of the pathological conformation, intercellular transfer, and the subsequent seeding of native forms of the same protein in the neighboring cell. Molecular chaperones play a major role in maintaining cellular proteostasis by assisting the (re)-folding of cellular proteins to ensure their function or by promoting the degradation of terminally misfolded proteins to prevent damage. With increasing age, however, the capacity of this proteostasis network tends to decrease, which enables the manifestation of neurodegenerative diseases. Recently, there has been a plethora of studies investigating how and when chaperones interact with disease-related proteins, which have advanced our understanding of the role of chaperones in protein misfolding diseases. This review article focuses on the steps of prion-like propagation from initial misfolding and self-templated replication to intercellular spreading and discusses the influence that chaperones have on these various steps, highlighting both the positive and adverse consequences chaperone action can have. Understanding how chaperones alleviate and aggravate disease progression is vital for the development of therapeutic strategies to combat these debilitating diseases.
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Affiliation(s)
- Jessica Tittelmeier
- German Cancer Research Center (DKFZ), Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Eliana Nachman
- German Cancer Research Center (DKFZ), Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Carmen Nussbaum-Krammer
- German Cancer Research Center (DKFZ), Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
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22
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Drew SC. Aldehyde Production as a Calibrant of Ultrasonic Power Delivery During Protein Misfolding Cyclic Amplification. Protein J 2020; 39:501-508. [PMID: 33011953 DOI: 10.1007/s10930-020-09920-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2020] [Indexed: 11/30/2022]
Abstract
The protein misfolding cyclic amplification (PMCA) technique employs repeated cycles of incubation and sonication to amplify minute amounts of misfolded protein conformers. Spontaneous (de novo) prion formation and ultrasonic power level represent two potentially interrelated sources of variation that frustrate attempts to replicate results from different laboratories. We previously established that water splitting during PMCA provides a radical-rich environment leading to oxidative damage to substrate molecules as well as the polypropylene PCR tubes used for sample containment. Here it is shown that the cross-linking agent formaldehyde is generated from buffer ions that are attacked by hydroxyl radicals. In addition, free radical damage to protein, nucleic acid, lipid, and detergent molecules produces a substantial concentration of aldehydes (hundreds of micromolar). The measurement of aldehydes using the Hantzsch reaction provides a reliable and inexpensive method for measuring the power delivered to individual PMCA samples, and for calibrating the power output characteristics of an individual sonicator. The proposed method may also be used to better account for inter-assay and inter-laboratory variation in prion replication and de novo prion generation, the latter of which may correlate with aldehyde-induced cross-linking of substrate molecules.
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Affiliation(s)
- Simon C Drew
- Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Victoria, 3010, Australia. .,Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, 02-106, Poland.
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The Role of Vesicle Trafficking Defects in the Pathogenesis of Prion and Prion-Like Disorders. Int J Mol Sci 2020; 21:ijms21197016. [PMID: 32977678 PMCID: PMC7582986 DOI: 10.3390/ijms21197016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/15/2020] [Accepted: 09/21/2020] [Indexed: 11/26/2022] Open
Abstract
Prion diseases are fatal and transmissible neurodegenerative diseases in which the cellular form of the prion protein ‘PrPc’, misfolds into an infectious and aggregation prone isoform termed PrPSc, which is the primary component of prions. Many neurodegenerative diseases, like Alzheimer’s disease, Parkinson’s disease, and polyglutamine diseases, such as Huntington’s disease, are considered prion-like disorders because of the common characteristics in the propagation and spreading of misfolded proteins that they share with the prion diseases. Unlike prion diseases, these are non-infectious outside experimental settings. Many vesicular trafficking impairments, which are observed in prion and prion-like disorders, favor the accumulation of the pathogenic amyloid aggregates. In addition, many of the vesicular trafficking impairments that arise in these diseases, turn out to be further aggravating factors. This review offers an insight into the currently known vesicular trafficking defects in these neurodegenerative diseases and their implications on disease progression. These findings suggest that these impaired trafficking pathways may represent similar therapeutic targets in these classes of neurodegenerative disorders.
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Hara H, Sakaguchi S. N-Terminal Regions of Prion Protein: Functions and Roles in Prion Diseases. Int J Mol Sci 2020; 21:ijms21176233. [PMID: 32872280 PMCID: PMC7504422 DOI: 10.3390/ijms21176233] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 08/25/2020] [Accepted: 08/27/2020] [Indexed: 01/30/2023] Open
Abstract
The normal cellular isoform of prion protein, designated PrPC, is constitutively converted to the abnormally folded, amyloidogenic isoform, PrPSc, in prion diseases, which include Creutzfeldt-Jakob disease in humans and scrapie and bovine spongiform encephalopathy in animals. PrPC is a membrane glycoprotein consisting of the non-structural N-terminal domain and the globular C-terminal domain. During conversion of PrPC to PrPSc, its 2/3 C-terminal region undergoes marked structural changes, forming a protease-resistant structure. In contrast, the N-terminal region remains protease-sensitive in PrPSc. Reverse genetic studies using reconstituted PrPC-knockout mice with various mutant PrP molecules have revealed that the N-terminal domain has an important role in the normal function of PrPC and the conversion of PrPC to PrPSc. The N-terminal domain includes various characteristic regions, such as the positively charged residue-rich polybasic region, the octapeptide repeat (OR) region consisting of five repeats of an octapeptide sequence, and the post-OR region with another positively charged residue-rich polybasic region followed by a stretch of hydrophobic residues. We discuss the normal functions of PrPC, the conversion of PrPC to PrPSc, and the neurotoxicity of PrPSc by focusing on the roles of the N-terminal regions in these topics.
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25
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Global analysis of protein degradation in prion infected cells. Sci Rep 2020; 10:10800. [PMID: 32612191 PMCID: PMC7329860 DOI: 10.1038/s41598-020-67505-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 04/06/2020] [Indexed: 12/02/2022] Open
Abstract
Prion diseases are rare, neurological disorders caused by the misfolding of the cellular prion protein (PrPC) into cytotoxic fibrils (PrPSc). Intracellular PrPSc aggregates primarily accumulate within late endosomes and lysosomes, organelles that participate in the degradation and turnover of a large subset of the proteome. Thus, intracellular accumulation of PrPSc aggregates has the potential to globally influence protein degradation kinetics within an infected cell. We analyzed the proteome-wide effect of prion infection on protein degradation rates in N2a neuroblastoma cells by dynamic stable isotopic labeling with amino acids in cell culture (dSILAC) and bottom-up proteomics. The analysis quantified the degradation rates of more than 4,700 proteins in prion infected and uninfected cells. As expected, the degradation rate of the prion protein is significantly decreased upon aggregation in infected cells. In contrast, the degradation kinetics of the remainder of the N2a proteome generally increases upon prion infection. This effect occurs concurrently with increases in the cellular activities of autophagy and some lysosomal hydrolases. The resulting enhancement in proteome flux may play a role in the survival of N2a cells upon prion infection.
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26
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Jones E, Mead S. Genetic risk factors for Creutzfeldt-Jakob disease. Neurobiol Dis 2020; 142:104973. [PMID: 32565065 DOI: 10.1016/j.nbd.2020.104973] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/18/2020] [Accepted: 06/13/2020] [Indexed: 10/24/2022] Open
Abstract
Prion diseases are a group of fatal neurodegenerative disorders of mammals that share a central role for prion protein (PrP, gene PRNP) in their pathogenesis. Prions are infectious agents that account for the observed transmission of prion diseases between humans and animals in certain circumstances. The prion mechanism invokes a misfolded and multimeric assembly of PrP (a prion) that grows by templating of the normal protein and propagates by fission. Aside from the medical and public health notoriety of acquired prion diseases, the conditions have attracted interest as it has been realized that common neurodegenerative disorders share so-called prion-like mechanisms. In this article we will expand on recent evidence for new genetic loci that alter the risk of human prion disease. The most common human prion disease, sporadic Creutzfeldt-Jakob disease (sCJD), is characterized by the seemingly spontaneous appearance of prions in the brain. Genetic variation within PRNP is associated with all types of prion diseases, in particular, heterozygous genotypes at codons 129 and 219 have long been known to be strong protective factors against sCJD. A large number of rare mutations have been described in PRNP that cause autosomal dominant inherited prion diseases. Two loci recently identified by genome-wide association study increase sCJD risk, including variants in or near to STX6 and GAL3ST1. STX6 encodes syntaxin-6, a component of SNARE complexes with cellular roles that include the fusion of intracellular vesicles with target membranes. GAL3ST1 encodes cerebroside sulfotransferase, the only enzyme that sulfates sphingolipids to make sulfatides, a major lipid component of myelin. We discuss how these roles may modify the pathogenesis of prion diseases and their relevance for other neurodegenerative disorders.
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Affiliation(s)
- Emma Jones
- MRC Prion Unit at University College London (UCL), UCL Institute of Prion Diseases, 33 Cleveland Street, W1W 7FF, United Kingdom
| | - Simon Mead
- MRC Prion Unit at University College London (UCL), UCL Institute of Prion Diseases, 33 Cleveland Street, W1W 7FF, United Kingdom.
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27
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Structural insight into conformational change in prion protein by breakage of electrostatic network around H187 due to its protonation. Sci Rep 2019; 9:19305. [PMID: 31848406 PMCID: PMC6917724 DOI: 10.1038/s41598-019-55808-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 11/04/2019] [Indexed: 11/10/2022] Open
Abstract
A conformational change from normal prion protein(PrPC) to abnormal prion protein(PrPSC) induces fatal neurodegenerative diseases. Acidic pH is well-known factors involved in the conformational change. Because the protonation of H187 is strongly linked to the change in PrP stability, we examined the charged residues R156, E196, and D202 around H187. Interestingly, there have been reports on pathological mutants, such as H187R, E196A, and D202N. In this study, we focused on how an acidic pH and pathological mutants disrupt this electrostatic network and how this broken network destabilizes PrP structure. To do so, we performed a temperature-based replica-exchange molecular dynamics (T-REMD) simulation using a cumulative 252 μs simulation time. We measured the distance between amino acids comprising four salt bridges (R156–E196/D202 and H187–E196/D202). Our results showed that the spatial configuration of the electrostatic network was significantly altered by an acidic pH and mutations. The structural alteration in the electrostatic network increased the RMSF value around the first helix (H1). Thus, the structural stability of H1, which is anchored to the H2–H3 bundle, was decreased. It induces separation of R156 from the electrostatic network. Analysis of the anchoring energy also shows that two salt-bridges (R156-E196/D202) are critical for PrP stability.
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28
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Hackl S, Becker CFW. Prion protein-Semisynthetic prion protein (PrP) variants with posttranslational modifications. J Pept Sci 2019; 25:e3216. [PMID: 31713950 PMCID: PMC6899880 DOI: 10.1002/psc.3216] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 08/23/2019] [Accepted: 08/23/2019] [Indexed: 12/16/2022]
Abstract
Deciphering the pathophysiologic events in prion diseases is challenging, and the role of posttranslational modifications (PTMs) such as glypidation and glycosylation remains elusive due to the lack of homogeneous protein preparations. So far, experimental studies have been limited in directly analyzing the earliest events of the conformational change of cellular prion protein (PrPC ) into scrapie prion protein (PrPSc ) that further propagates PrPC misfolding and aggregation at the cellular membrane, the initial site of prion infection, and PrP misfolding, by a lack of suitably modified PrP variants. PTMs of PrP, especially attachment of the glycosylphosphatidylinositol (GPI) anchor, have been shown to be crucially involved in the PrPSc formation. To this end, semisynthesis offers a unique possibility to understand PrP behavior invitro and invivo as it provides access to defined site-selectively modified PrP variants. This approach relies on the production and chemoselective linkage of peptide segments, amenable to chemical modifications, with recombinantly produced protein segments. In this article, advances in understanding PrP conversion using semisynthesis as a tool to obtain homogeneous posttranslationally modified PrP will be discussed.
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Affiliation(s)
- Stefanie Hackl
- University of Vienna, Faculty of Chemistry, Institute of Biological Chemistry, Vienna, Austria
| | - Christian F W Becker
- University of Vienna, Faculty of Chemistry, Institute of Biological Chemistry, Vienna, Austria
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29
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The N-Terminal Polybasic Region of Prion Protein Is Crucial in Prion Pathogenesis Independently of the Octapeptide Repeat Region. Mol Neurobiol 2019; 57:1203-1216. [DOI: 10.1007/s12035-019-01804-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 09/26/2019] [Indexed: 10/25/2022]
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30
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Sengupta I, Udgaonkar J. Monitoring site-specific conformational changes in real-time reveals a misfolding mechanism of the prion protein. eLife 2019; 8:44698. [PMID: 31232689 PMCID: PMC6590988 DOI: 10.7554/elife.44698] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 06/11/2019] [Indexed: 11/25/2022] Open
Abstract
During pathological aggregation, proteins undergo remarkable conformational re-arrangements to anomalously assemble into a heterogeneous collection of misfolded multimers, ranging from soluble oligomers to insoluble amyloid fibrils. Inspired by fluorescence resonance energy transfer (FRET) measurements of protein folding, an experimental strategy to study site-specific misfolding kinetics during aggregation, by effectively suppressing contributions from inter-molecular FRET, is described. Specifically, the kinetics of conformational changes across different secondary and tertiary structural segments of the mouse prion protein (moPrP) were monitored independently, after the monomeric units transformed into large oligomers OL, which subsequently disaggregated reversibly into small oligomers OS at pH 4. The sequence segments spanning helices α2 and α3 underwent a compaction during the formation of OL and elongation into β-sheets during the formation of OS. The β1-α1-β2 and α2-α3 subdomains were separated, and the helix α1 was unfolded to varying extents in both OL and OS.
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Affiliation(s)
- Ishita Sengupta
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru, India
| | - Jayant Udgaonkar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru, India
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31
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Vorberg IM. All the Same? The Secret Life of Prion Strains within Their Target Cells. Viruses 2019; 11:v11040334. [PMID: 30970585 DOI: 10.3390/v11040334] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 04/02/2019] [Accepted: 04/05/2019] [Indexed: 01/23/2023] Open
Abstract
Prions are infectious β-sheet-rich protein aggregates composed of misfolded prion protein (PrPSc) that do not possess coding nucleic acid. Prions replicate by recruiting and converting normal cellular PrPC into infectious isoforms. In the same host species, prion strains target distinct brain regions and cause different disease phenotypes. Prion strains are associated with biophysically distinct PrPSc conformers, suggesting that strain properties are enciphered within alternative PrPSc quaternary structures. So far it is unknown how prion strains target specific cells and initiate productive infections. Deeper mechanistic insight into the prion life cycle came from cell lines permissive to a range of different prion strains. Still, it is unknown why certain cell lines are refractory to infection by one strain but permissive to another. While pharmacologic and genetic manipulations revealed subcellular compartments involved in prion replication, little is known about strain-specific requirements for endocytic trafficking pathways. This review summarizes our knowledge on how prions replicate within their target cells and on strain-specific differences in prion cell biology.
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Affiliation(s)
- Ina M Vorberg
- German Center for Neurodegenerative Diseases (DZNE e.V.), Sigmund-Freud-Strasse 27, 53127 Bonn, Germany.
- Rheinische Friedrich-Wilhelms-Universität Bonn, 53127 Bonn, Germany.
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32
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Bartoletti-Stella A, Corrado P, Mometto N, Baiardi S, Durrenberger PF, Arzberger T, Reynolds R, Kretzschmar H, Capellari S, Parchi P. Analysis of RNA Expression Profiles Identifies Dysregulated Vesicle Trafficking Pathways in Creutzfeldt-Jakob Disease. Mol Neurobiol 2018; 56:5009-5024. [PMID: 30446946 DOI: 10.1007/s12035-018-1421-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 11/01/2018] [Indexed: 12/21/2022]
Abstract
Functional genomics applied to the study of RNA expression profiles identified several abnormal molecular processes in experimental prion disease. However, only a few similar studies have been carried out to date in a naturally occurring human prion disease. To better characterize the transcriptional cascades associated with sporadic Creutzfeldt-Jakob disease (sCJD), the most common human prion disease, we investigated the global gene expression profile in samples from the frontal cortex of 10 patients with sCJD and 10 non-neurological controls by microarray analysis. The comparison identified 333 highly differentially expressed genes (hDEGs) in sCJD. Functional enrichment Gene Ontology analysis revealed that hDEGs were mainly associated with synaptic transmission, including GABA (q value = 0.049) and glutamate (q value = 0.005) signaling, and the immune/inflammatory response. Furthermore, the analysis of cellular components performed on hDEGs showed a compromised regulation of vesicle-mediated transport with mainly up-regulated genes related to the endosome (q value = 0.01), lysosome (q value = 0.04), and extracellular exosome (q value < 0.01). A targeted analysis of the retromer core component VPS35 (vacuolar protein sorting-associated protein 35) showed a down-regulation of gene expression (p value= 0.006) and reduced brain protein levels (p value= 0.002). Taken together, these results confirm and expand previous microarray expression profile data in sCJD. Most significantly, they also demonstrate the involvement of the endosomal-lysosomal system. Since the latter is a common pathogenic pathway linking together diseases, such as Alzheimer's and Parkinson's, it might be the focus of future studies aimed to identify new therapeutic targets in neurodegenerative diseases.
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Affiliation(s)
- Anna Bartoletti-Stella
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Ospedale Bellaria, 40139, Bologna, Italy
| | - Patrizia Corrado
- Department of Biomedical and NeuroMotor Sciences, DIBINEM, University of Bologna, 40123, Bologna, Italy
| | - Nicola Mometto
- Department of Biomedical and NeuroMotor Sciences, DIBINEM, University of Bologna, 40123, Bologna, Italy
| | - Simone Baiardi
- Department of Biomedical and NeuroMotor Sciences, DIBINEM, University of Bologna, 40123, Bologna, Italy
| | - Pascal F Durrenberger
- Centre for Inflammation and Tissue Repair, UCL Respiratory, University College London, Rayne Building, London, UK
| | - Thomas Arzberger
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University Munich, Munich, Germany.,Center for Neuropathology and Prion Research, Ludwig-Maximilians-University Munich, Munich, Germany
| | | | - Hans Kretzschmar
- Center for Neuropathology and Prion Research, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Sabina Capellari
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Ospedale Bellaria, 40139, Bologna, Italy. .,Department of Biomedical and NeuroMotor Sciences, DIBINEM, University of Bologna, 40123, Bologna, Italy.
| | - Piero Parchi
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Ospedale Bellaria, 40139, Bologna, Italy. .,Department of Experimental, Diagnostic and Specialty Medicine, DIMES, University of Bologna, 40138, Bologna, Italy.
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Abstract
The development of multiple cell culture models of prion infection over the last two decades has led to a significant increase in our understanding of how prions infect cells. In particular, new techniques to distinguish exogenous from endogenous prions have allowed us for the first time to look in depth at the earliest stages of prion infection through to the establishment of persistent infection. These studies have shown that prions can infect multiple cell types, both neuronal and nonneuronal. Once in contact with the cell, they are rapidly taken up via multiple endocytic pathways. After uptake, the initial replication of prions occurs almost immediately on the plasma membrane and within multiple endocytic compartments. Following this acute stage of prion replication, persistent prion infection may or may not be established. Establishment of a persistent prion infection in cells appears to depend upon the achievement of a delicate balance between the rate of prion replication and degradation, the rate of cell division, and the efficiency of prion spread from cell to cell. Overall, cell culture models have shown that prion infection of the cell is a complex and variable process which can involve multiple cellular pathways and compartments even within a single cell.
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Affiliation(s)
- Suzette A Priola
- Laboratory of Persistent Viral Diseases, National Institute of Allergy and Infectious Diseases, Hamilton, MT, United States.
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34
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Sengupta I, Udgaonkar JB. Structural mechanisms of oligomer and amyloid fibril formation by the prion protein. Chem Commun (Camb) 2018; 54:6230-6242. [PMID: 29789820 DOI: 10.1039/c8cc03053g] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Misfolding and aggregation of the prion protein is responsible for multiple neurodegenerative diseases. Works from several laboratories on folding of both the WT and multiple pathogenic mutant variants of the prion protein have identified several structurally dissimilar intermediates, which might be potential precursors to misfolding and aggregation. The misfolded aggregates themselves are morphologically distinct, critically dependent on the solution conditions under which they are prepared, but always β-sheet rich. Despite the lack of an atomic resolution structure of the infectious pathogenic agent in prion diseases, several low resolution models have identified the β-sheet rich core of the aggregates formed in vitro, to lie in the α2-α3 subdomain of the prion protein, albeit with local stabilities that vary with the type of aggregate. This feature article describes recent advances in the investigation of in vitro prion protein aggregation using multiple spectroscopic probes, with particular focus on (1) identifying aggregation-prone conformations of the monomeric protein, (2) conditions which trigger misfolding and oligomerization, (3) the mechanism of misfolding and aggregation, and (4) the structure of the misfolded intermediates and final aggregates.
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Affiliation(s)
- Ishita Sengupta
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
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35
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Retrograde Transport by Clathrin-Coated Vesicles is Involved in Intracellular Transport of PrP Sc in Persistently Prion-Infected Cells. Sci Rep 2018; 8:12241. [PMID: 30115966 PMCID: PMC6095914 DOI: 10.1038/s41598-018-30775-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 08/03/2018] [Indexed: 12/22/2022] Open
Abstract
Intracellular dynamics of an abnormal isoform of prion protein (PrPSc) are tightly associated with prion propagation. However, the machineries involved in the intracellular trafficking of PrPSc are not fully understood. Our previous study suggested that PrPSc in persistently prion-infected cells dynamically circulates between endocytic-recycling compartments (ERCs) and peripheral regions of the cells. To investigate these machineries, we focused on retrograde transport from endosomes to the trans-Golgi network, which is one of the pathways involved in recycling of molecules. PrPSc was co-localized with components of clathrin-coated vesicles (CCVs) as well as those of the retromer complex, which are known as machineries for retrograde transport. Fractionation of intracellular compartments by density gradient centrifugation showed the presence of PrPSc and the components of CCVs in the same fractions. Furthermore, PrPSc was detected in CCVs isolated from intracellular compartments of prion-infected cells. Knockdown of clathrin interactor 1, which is one of the clathrin adaptor proteins involved in retrograde transport, did not change the amount of PrPSc, but it altered the distribution of PrPSc from ERCs to peripheral regions, including late endosomes/lysosomes. These data demonstrated that some PrPSc is transported from endosomes to ERCs by CCVs, which might be involved in the recycling of PrPSc.
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36
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Honda R, Yamaguchi KI, Elhelaly AE, Fuji M, Kuwata K. Poly-L-histidine inhibits prion propagation in a prion-infected cell line. Prion 2018; 12:226-233. [PMID: 30074430 DOI: 10.1080/19336896.2018.1505395] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Transmissible spongiform encephalopathies (TSEs) are a group of lethal neurodegenerative diseases involving the structural conversion of cellular prion protein (PrPC) into the pathogenic isoform (PrPSc) for which no effective treatment is currently available. Previous studies have implicated that a polymeric molecule with a repeating unit, such as pentosane polysulfate and polyamidoamide dendrimers, exhibits a potent anti-prion activity, suggesting that poly-(amino acid)s could be a candidate molecule for inhibiting prion propagation. Here, by screening a series of poly-(amino acid)s in a prion-infected neuroblastoma cell line (GTFK), we identified poly-L-His as a novel anti-prion compound with an IC50 value of 1.8 µg/mL (0.18 µM). This potent anti-prion activity was specific to a high-molecular-weight poly-L-His and absent in monomeric histidine or low-molecular-weight poly-L-His. Solution NMR data indicated that poly-L-His directly binds to the loop region connecting Helix 2 and Helix 3 of PrPC and sterically blocks the structural conversion toward PrPSc. Poly-L-His, however, did not inhibit prion propagation in a prion-infected mouse when administered intraperitoneally, suggesting that the penetration of blood-brain barrier and/or the chemical stability of this polypeptide must be addressed before its application in vivo. Taken together, this study revealed the potential use of poly-L-His as a novel treatment against TSEs. (203 words).
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Affiliation(s)
- Ryo Honda
- a United Graduate School of Drug Discovery and Medical Information Sciences , Gifu University , Gifu , Japan
| | | | - Abdelazim Elsayed Elhelaly
- a United Graduate School of Drug Discovery and Medical Information Sciences , Gifu University , Gifu , Japan
| | - Mitsuhiko Fuji
- a United Graduate School of Drug Discovery and Medical Information Sciences , Gifu University , Gifu , Japan
| | - Kazuo Kuwata
- a United Graduate School of Drug Discovery and Medical Information Sciences , Gifu University , Gifu , Japan.,c Department of Gene and Development , Graduate School of Medicine, Gifu University , Gifu , Japan
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37
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Gao Y, Zhu T, Zhang C, Zhang JZ, Mei Y. Comparison of the unfolding and oligomerization of human prion protein under acidic and neutral environments by molecular dynamics simulations. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.07.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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38
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Pankiewicz JE, Sanchez S, Kirshenbaum K, Kascsak RB, Kascsak RJ, Sadowski MJ. Anti-prion Protein Antibody 6D11 Restores Cellular Proteostasis of Prion Protein Through Disrupting Recycling Propagation of PrP Sc and Targeting PrP Sc for Lysosomal Degradation. Mol Neurobiol 2018; 56:2073-2091. [PMID: 29987703 DOI: 10.1007/s12035-018-1208-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 06/26/2018] [Indexed: 10/28/2022]
Abstract
PrPSc is an infectious and disease-specific conformer of the prion protein, which accumulation in the CNS underlies the pathology of prion diseases. PrPSc replicates by binding to the cellular conformer of the prion protein (PrPC) expressed by host cells and rendering its secondary structure a likeness of itself. PrPC is a plasma membrane anchored protein, which constitutively recirculates between the cell surface and the endocytic compartment. Since PrPSc engages PrPC along this trafficking pathway, its replication process is often referred to as "recycling propagation." Certain monoclonal antibodies (mAbs) directed against prion protein can abrogate the presence of PrPSc from prion-infected cells. However, the precise mechanism(s) underlying their therapeutic propensities remains obscure. Using N2A murine neuroblastoma cell line stably infected with 22L mouse-adapted scrapie strain (N2A/22L), we investigated here the modus operandi of the 6D11 clone, which was raised against the PrPSc conformer and has been shown to permanently clear prion-infected cells from PrPSc presence. We determined that 6D11 mAb engages and sequesters PrPC and PrPSc at the cell surface. PrPC/6D11 and PrPSc/6D11 complexes are then endocytosed from the plasma membrane and are directed to lysosomes, therefore precluding recirculation of nascent PrPSc back to the cell surface. Targeting PrPSc by 6D11 mAb to the lysosomal compartment facilitates its proteolysis and eventually shifts the balance between PrPSc formation and degradation. Ongoing translation of PrPC allows maintaining the steady-state level of prion protein within the cells, which was not depleted under 6D11 mAb treatment. Our findings demonstrate that through disrupting recycling propagation of PrPSc and promoting its degradation, 6D11 mAb restores cellular proteostasis of prion protein.
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Affiliation(s)
- Joanna E Pankiewicz
- Department of Neurology, New York University School of Medicine, 550 First Avenue, Science Building, Room 1007, New York, NY, 10016, USA.,Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
| | - Sandrine Sanchez
- Department of Neurology, New York University School of Medicine, 550 First Avenue, Science Building, Room 1007, New York, NY, 10016, USA
| | - Kent Kirshenbaum
- Department of Chemistry, New York University, New York, NY, 10003, USA
| | - Regina B Kascsak
- New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, 10314, USA
| | - Richard J Kascsak
- New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, 10314, USA
| | - Martin J Sadowski
- Department of Neurology, New York University School of Medicine, 550 First Avenue, Science Building, Room 1007, New York, NY, 10016, USA. .,Department of Psychiatry, New York University School of Medicine, New York, NY, 10016, USA. .,Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA.
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Vilette D, Courte J, Peyrin JM, Coudert L, Schaeffer L, Andréoletti O, Leblanc P. Cellular mechanisms responsible for cell-to-cell spreading of prions. Cell Mol Life Sci 2018; 75:2557-2574. [PMID: 29761205 PMCID: PMC11105574 DOI: 10.1007/s00018-018-2823-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 04/04/2018] [Accepted: 04/23/2018] [Indexed: 01/01/2023]
Abstract
Prions are infectious agents that cause fatal neurodegenerative diseases. Current evidence indicates that they are essentially composed of an abnormally folded protein (PrPSc). These abnormal aggregated PrPSc species multiply in infected cells by recruiting and converting the host PrPC protein into new PrPSc. How prions move from cell to cell and progressively spread across the infected tissue is of crucial importance and may provide experimental opportunity to delay the progression of the disease. In infected cells, different mechanisms have been identified, including release of infectious extracellular vesicles and intercellular transfer of PrPSc-containing organelles through tunneling nanotubes. These findings should allow manipulation of the intracellular trafficking events targeting PrPSc in these particular subcellular compartments to experimentally address the relative contribution of these mechanisms to in vivo prion pathogenesis. In addition, such information may prompt further experimental strategies to decipher the causal roles of protein misfolding and aggregation in other human neurodegenerative diseases.
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Affiliation(s)
- Didier Vilette
- UMR1225, INRA, ENVT, Ecole Nationale Vétérinaire, 23 Chemin des Capelles, Toulouse, France.
| | - Josquin Courte
- Neurosciences Paris Seine, UMR8246, Inserm U1130, IBPS, UPMC, Sorbonne Universités, 4 Place Jussieu, 75005, Paris, France
- Laboratoire Physico Chimie Curie, UMR168, UPMC, IPGG, Sorbonne Universités, 6 Rue Jean Calvin, 75005, Paris, France
| | - Jean Michel Peyrin
- Neurosciences Paris Seine, UMR8246, Inserm U1130, IBPS, UPMC, Sorbonne Universités, 4 Place Jussieu, 75005, Paris, France.
| | - Laurent Coudert
- Insitut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon I, 8 Avenue Rockefeller, 69373, Lyon Cedex 08, France
| | - Laurent Schaeffer
- Insitut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon I, 8 Avenue Rockefeller, 69373, Lyon Cedex 08, France
| | - Olivier Andréoletti
- UMR1225, INRA, ENVT, Ecole Nationale Vétérinaire, 23 Chemin des Capelles, Toulouse, France
| | - Pascal Leblanc
- Insitut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon I, 8 Avenue Rockefeller, 69373, Lyon Cedex 08, France.
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Bera A, Biring S. A quantitative characterization of interaction between prion protein with nucleic acids. Biochem Biophys Rep 2018; 14:114-124. [PMID: 29872743 PMCID: PMC5986701 DOI: 10.1016/j.bbrep.2018.04.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/10/2018] [Accepted: 04/12/2018] [Indexed: 02/06/2023] Open
Abstract
Binding of recombinant prion protein with small highly structured RNAs, prokaryotic and eukaryotic prion protein mRNA pseudoknots, tRNA and polyA has been studied by the change in fluorescence anisotropy of the intrinsic tryptophan groups of the protein. The affinities of these RNAs to the prion protein and the number of sites where the protein binds to the nucleic acids do not vary appreciably although the RNAs have very different compositions and structures. The binding parameters do not depend upon pH of the solution and show a poor co-operativity. The reactants form larger nucleoprotein complexes at pH 5 compared to that at neutral pH. The electrostatic force between the protein and nucleic acids dominates the binding interaction at neutral pH. In contrast, nucleic acid interaction with the incipient nonpolar groups exposed from the structured region of the prion protein dominates the reaction at pH 5. Prion protein of a particular species forms larger complexes with prion protein mRNA pseudoknots of the same species. The structure of the pseudoknots and not their base sequences probably dominates their interaction with prion protein. Possibilities of the conversion of the prion protein to its infectious form in the cytoplasm by nucleic acids have been discussed.
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Affiliation(s)
- Alakesh Bera
- Infectiologie Animale et Santé Publique, Institut National de la Recherche Agronomique, 37380 Nouzilly, France
| | - Sajal Biring
- Department of Electronic Engineering and Organic Electronics Research Center, Ming-Chi University of Technology, 84 Gungjuan Rd., Taishan Dist., New Taipei City 24301, Taiwan
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Lysosomal response in relation to α-synuclein pathology differs between Parkinson's disease and multiple system atrophy. Neurobiol Dis 2018; 114:140-152. [PMID: 29505813 DOI: 10.1016/j.nbd.2018.02.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 01/26/2018] [Accepted: 02/27/2018] [Indexed: 12/20/2022] Open
Abstract
Intracellular deposition of pathologically altered α-synuclein mostly in neurons characterises Parkinson's disease (PD), while its accumulation predominantly in oligodendrocytes is a feature of multiple system atrophy (MSA). Recently a prion-like spreading of pathologic α-synuclein has been suggested to play a role in the pathogenesis of PD and MSA. This implicates a role of protein processing systems, including lysosomes, supported also by genetic studies in PD. However, particularly for MSA, the mechanism of cell-to-cell propagation of α-synuclein is yet not fully understood. To evaluate the significance of lysosomal response, we systematically compared differently affected neuronal populations in PD, MSA, and non-diseased brains using morphometric immunohistochemistry (cathepsin D), double immunolabelling (cathepsin D/α-synuclein) laser confocal microscopy, and immunogold electron microscopy for the disease associated α-synuclein. We found that i) irrespective of the presence of neuronal inclusions, the volume density of cathepsin D immunoreactivity significantly increases in affected neurons of the pontine base in MSA brains; ii) volume density of cathepsin D immunoreactivity increases in nigral neurons in PD without inclusions and with non-ubiquitinated pre-aggregates of α-synuclein, but not in neurons with Lewy bodies; iii) cathepsin D immunoreactivity frequently colocalises with α-synuclein pre-aggregates in nigral neurons in PD; iv) ultrastructural observations confirm disease-associated α-synuclein in neuronal and astrocytic lysosomes in PD; v) lysosome-associated α-synuclein is observed in astroglia and rarely in oligodendroglia and in neurons in MSA. Our observations support a crucial role for the neuronal endosomal-lysosomal system in the processing of α-synuclein in PD. We suggest a distinct contribution of lysosomes to the pathogenesis of MSA, including the possibility of oligodendroglial and eventually neuronal uptake of exogenous α-synuclein in MSA.
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Hecel A, Draghi S, Valensin D, Kozlowski H. The effect of a membrane-mimicking environment on the interactions of Cu 2+ with an amyloidogenic fragment of chicken prion protein. Dalton Trans 2018; 46:7758-7769. [PMID: 28589973 DOI: 10.1039/c7dt01069a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Prion proteins (PrP) from different species have the ability to tightly bind Cu2+ ions. Copper coordination sites are located in the disordered and flexible N-terminal region which contains several His anchoring sites. Among them, two His residues are found in the so called amyloidogenic PrP region which is believed to play a key role in the process leading to oligomer and fibril formation. Both chicken and human amyloidogenic regions have a hydrophobic C-terminal region rich in Ala and Val amino acids. Recent findings revealed that this domain undergoes random coil to α-helix structuring upon interaction with membrane models. This interaction might strongly impact metal binding abilities either in terms of donor sets or affinity. In this study we investigated Cu2+ interaction with an amyloidogenic fragment, chPrP105-140, derived from chicken prion protein (chPrP), in different solution environments. The behavior of the peptide and its metal complexes was analyzed in water and in the presence of negative and positive charged membrane mimicking environments formed by sodium dodecyl sulfate (SDS) and dodecyl trimethyl ammonium chloride (DTAC) micelles. The metal coordination sphere, the metal binding affinity and stoichiometry were evaluated by combining spectroscopic and potentiometric methods. Finally we compare copper(ii) interactions with human and chicken amyloidogenic fragments. Our results indicate that the chicken amyloidogenic fragment is a stronger copper ligand than the human amyloidogenic fragment.
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Affiliation(s)
- Aleksandra Hecel
- Faculty of Chemistry, University of Wroclaw, F. Joliot-Curie 14., 50-383 Wroclaw, Poland
| | - Sara Draghi
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Via A. Moro 2, 53100 Siena, Italy.
| | - Daniela Valensin
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Via A. Moro 2, 53100 Siena, Italy.
| | - Henryk Kozlowski
- Public Higher Medical Professional School in Opole, Katowicka 68, 45060 Opole, Poland
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Prion Protein Devoid of the Octapeptide Repeat Region Delays Bovine Spongiform Encephalopathy Pathogenesis in Mice. J Virol 2017; 92:JVI.01368-17. [PMID: 29046443 DOI: 10.1128/jvi.01368-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 10/05/2017] [Indexed: 12/26/2022] Open
Abstract
Conformational conversion of the cellular isoform of prion protein, PrPC, into the abnormally folded, amyloidogenic isoform, PrPSc, is a key pathogenic event in prion diseases, including Creutzfeldt-Jakob disease in humans and scrapie and bovine spongiform encephalopathy (BSE) in animals. We previously reported that the octapeptide repeat (OR) region could be dispensable for converting PrPC into PrPSc after infection with RML prions. We demonstrated that mice transgenically expressing mouse PrP with deletion of the OR region on the PrP knockout background, designated Tg(PrPΔOR)/Prnp0/0 mice, did not show reduced susceptibility to RML scrapie prions, with abundant accumulation of PrPScΔOR in their brains. We show here that Tg(PrPΔOR)/Prnp0/0 mice were highly resistant to BSE prions, developing the disease with markedly elongated incubation times after infection with BSE prions. The conversion of PrPΔOR into PrPScΔOR was markedly delayed in their brains. These results suggest that the OR region may have a crucial role in the conversion of PrPC into PrPSc after infection with BSE prions. However, Tg(PrPΔOR)/Prnp0/0 mice remained susceptible to RML and 22L scrapie prions, developing the disease without elongated incubation times after infection with RML and 22L prions. PrPScΔOR accumulated only slightly less in the brains of RML- or 22L-infected Tg(PrPΔOR)/Prnp0/0 mice than PrPSc in control wild-type mice. Taken together, these results indicate that the OR region of PrPC could play a differential role in the pathogenesis of BSE prions and RML or 22L scrapie prions.IMPORTANCE Structure-function relationship studies of PrPC conformational conversion into PrPSc are worthwhile to understand the mechanism of the conversion of PrPC into PrPSc We show here that, by inoculating Tg(PrPΔOR)/Prnp0/0 mice with the three different strains of RML, 22L, and BSE prions, the OR region could play a differential role in the conversion of PrPC into PrPSc after infection with RML or 22L scrapie prions and BSE prions. PrPΔOR was efficiently converted into PrPScΔOR after infection with RML and 22L prions. However, the conversion of PrPΔOR into PrPScΔOR was markedly delayed after infection with BSE prions. Further investigation into the role of the OR region in the conversion of PrPC into PrPSc after infection with BSE prions might be helpful for understanding the pathogenesis of BSE prions.
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Cheng L, Zhao W, Hill AF. Exosomes and their role in the intercellular trafficking of normal and disease associated prion proteins. Mol Aspects Med 2017; 60:62-68. [PMID: 29196098 DOI: 10.1016/j.mam.2017.11.011] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 11/08/2017] [Accepted: 11/27/2017] [Indexed: 12/13/2022]
Abstract
Over the past decade, small extracellular vesicles called exosomes have been observed to harbour protein and genetic cargo that can assist in health and also cause disease. Many groups are extensively investigating the mechanisms involved that regulate the trafficking and packaging of exosomal contents and how these processes may be deregulated in disease. Prion diseases are transmissible neurodegenerative disorders and are characterized by the presence of detectable misfolded prion proteins. The disease associated form of the prion protein can be found in exosomes and its transmissible properties have provided a reliable experimental read out that can be used to understand how exosomes and their cargo are involved in cell-cell communication and in the spread of prion diseases. This review reports on the current understanding of how exosomes are involved in the intercellular spread of infectious prions. Furthermore, we discuss how these principles are leading future investigations in developing new exosome based diagnostic tools and therapeutic drugs that could be applied to other neurodegenerative diseases.
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Affiliation(s)
- Lesley Cheng
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
| | - Wenting Zhao
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
| | - Andrew F Hill
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia.
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Mabbott NA. How do PrP Sc Prions Spread between Host Species, and within Hosts? Pathogens 2017; 6:pathogens6040060. [PMID: 29186791 PMCID: PMC5750584 DOI: 10.3390/pathogens6040060] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 11/16/2017] [Accepted: 11/21/2017] [Indexed: 12/22/2022] Open
Abstract
Prion diseases are sub-acute neurodegenerative diseases that affect humans and some domestic and free-ranging animals. Infectious prion agents are considered to comprise solely of abnormally folded isoforms of the cellular prion protein known as PrPSc. Pathology during prion disease is restricted to the central nervous system where it causes extensive neurodegeneration and ultimately leads to the death of the host. The first half of this review provides a thorough account of our understanding of the various ways in which PrPSc prions may spread between individuals within a population, both horizontally and vertically. Many natural prion diseases are acquired peripherally, such as by oral exposure, lesions to skin or mucous membranes, and possibly also via the nasal cavity. Following peripheral exposure, some prions accumulate to high levels within the secondary lymphoid organs as they make their journey from the site of infection to the brain, a process termed neuroinvasion. The replication of PrPSc prions within secondary lymphoid organs is important for their efficient spread to the brain. The second half of this review describes the key tissues, cells and molecules which are involved in the propagation of PrPSc prions from peripheral sites of exposure (such as the lumen of the intestine) to the brain. This section also considers how additional factors such as inflammation and aging might influence prion disease susceptibility.
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Affiliation(s)
- Neil A Mabbott
- The Roslin Institute & Royal (Dick) School of Veterinary Sciences, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
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46
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Sakaguchi S, Uchiyama K. Novel amplification mechanism of prions through disrupting sortilin-mediated trafficking. Prion 2017; 11:398-404. [PMID: 29099278 DOI: 10.1080/19336896.2017.1391435] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Conformational conversion of the cellular prion protein, PrPC, into the abnormally folded isoform of prion protein, PrPSc, which leads to marked accumulation of PrPSc in brains, is a key pathogenic event in prion diseases, a group of fatal neurodegenerative disorders caused by prions. However, the exact mechanism of PrPSc accumulation in prion-infected neurons remains unknown. We recently reported a novel cellular mechanism to support PrPSc accumulation in prion-infected neurons, in which PrPSc itself promotes its accumulation by evading the cellular inhibitory mechanism, which is newly identified in our recent study. We showed that the VPS10P sorting receptor sortilin negatively regulates PrPSc accumulation in prion-infected neurons, by interacting with PrPC and PrPSc and trafficking them to lysosomes for degradation. However, PrPSc stimulated lysosomal degradation of sortilin, disrupting the sortilin-mediated degradation of PrPC and PrPSc and eventually evoking further accumulation of PrPSc in prion-infected neurons. These findings suggest a positive feedback amplification mechanism for PrPSc accumulation in prion-infected neurons.
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Affiliation(s)
- Suehiro Sakaguchi
- a Division of Molecular Neurobiology, Institute for Enzyme Research (KOSOKEN), Tokushima University , Tokushima , Japan
| | - Keiji Uchiyama
- a Division of Molecular Neurobiology, Institute for Enzyme Research (KOSOKEN), Tokushima University , Tokushima , Japan
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Immunization of cervidized transgenic mice with multimeric deer prion protein induces self-antibodies that antagonize chronic wasting disease infectivity in vitro. Sci Rep 2017; 7:10538. [PMID: 28874781 PMCID: PMC5585258 DOI: 10.1038/s41598-017-11235-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 08/18/2017] [Indexed: 12/14/2022] Open
Abstract
Chronic wasting disease (CWD) is the most contagious prion disease. It is expanding rapidly in North America, was found recently in Europe, and the potential for transmission to humans cannot be excluded yet. We hypothesized that it is possible to prevent peripheral CWD infection and CWD prion shedding by inducing auto-antibodies against the cellular prion protein (PrPC) by active vaccination. Our objective is to overcome self-tolerance against PrP by using a multimeric recombinant PrP (recPrP) as an immunogen. We expressed in E. coli, purified and refolded four immunogens: cervid and murine recPrP in monomeric and dimeric form. Testing immunogenicity in sera of the vaccinated transgenic mice expressing cervid PrP revealed that all four immunogens effectively overcame self-tolerance against the prion protein as shown by high antibody titers. Confocal microscopy analysis revealed effective binding of post-immune sera to surface-located PrPC in both murine and cervid PrP expressing cultured cells. Remarkably, the post-immune auto-antibodies effectively inhibited CWD-induced prion conversion in RT-QuIC assay when incubated with either PrP substrate or CWD seed. Furthermore, they mitigated prion propagation in CWD-infected cervid-PrP expressing RK13 cells. Together, multimeric recombinant cervid PrP effectively overcomes self-tolerance to PrP and induces auto-antibodies that interfere with CWD conversion in vitro.
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Fehlinger A, Wolf H, Hossinger A, Duernberger Y, Pleschka C, Riemschoss K, Liu S, Bester R, Paulsen L, Priola SA, Groschup MH, Schätzl HM, Vorberg IM. Prion strains depend on different endocytic routes for productive infection. Sci Rep 2017; 7:6923. [PMID: 28761068 PMCID: PMC5537368 DOI: 10.1038/s41598-017-07260-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 06/27/2017] [Indexed: 01/08/2023] Open
Abstract
Prions are unconventional agents composed of misfolded prion protein that cause fatal neurodegenerative diseases in mammals. Prion strains induce specific neuropathological changes in selected brain areas. The mechanism of strain-specific cell tropism is unknown. We hypothesised that prion strains rely on different endocytic routes to invade and replicate within their target cells. Using prion permissive cells, we determined how impairment of endocytosis affects productive infection by prion strains 22L and RML. We demonstrate that early and late stages of prion infection are differentially sensitive to perturbation of clathrin- and caveolin-mediated endocytosis. Manipulation of canonical endocytic pathways only slightly influenced prion uptake. However, blocking the same routes had drastic strain-specific consequences on the establishment of infection. Our data argue that prion strains use different endocytic pathways for infection and suggest that cell type-dependent differences in prion uptake could contribute to host cell tropism.
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Affiliation(s)
- Andrea Fehlinger
- Deutsches Zentrum für Neurodegenerative Erkrankungen e.V., Sigmund-Freud-Strasse 27, 53127, Bonn, Germany
| | - Hanna Wolf
- Deutsches Zentrum für Neurodegenerative Erkrankungen e.V., Sigmund-Freud-Strasse 27, 53127, Bonn, Germany
| | - André Hossinger
- Deutsches Zentrum für Neurodegenerative Erkrankungen e.V., Sigmund-Freud-Strasse 27, 53127, Bonn, Germany
| | - Yvonne Duernberger
- Deutsches Zentrum für Neurodegenerative Erkrankungen e.V., Sigmund-Freud-Strasse 27, 53127, Bonn, Germany
| | - Catharina Pleschka
- Deutsches Zentrum für Neurodegenerative Erkrankungen e.V., Sigmund-Freud-Strasse 27, 53127, Bonn, Germany
| | - Katrin Riemschoss
- Deutsches Zentrum für Neurodegenerative Erkrankungen e.V., Sigmund-Freud-Strasse 27, 53127, Bonn, Germany
| | - Shu Liu
- Deutsches Zentrum für Neurodegenerative Erkrankungen e.V., Sigmund-Freud-Strasse 27, 53127, Bonn, Germany
| | - Romina Bester
- Institut für Virologie, Technische Universität München, Trogerstr. 30, 81675, München, Germany
| | - Lydia Paulsen
- Deutsches Zentrum für Neurodegenerative Erkrankungen e.V., Sigmund-Freud-Strasse 27, 53127, Bonn, Germany
| | - Suzette A Priola
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South 4th Street, Hamilton, MT, 59840, USA
| | - Martin H Groschup
- Friedrich-Loeffler-Institut, Institute of Novel and Emerging Infectious Diseases, 17493, Greifswald-Insel Riems, Germany
| | - Hermann M Schätzl
- Dept. of Comparative Biology & Experimental Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Ina M Vorberg
- Deutsches Zentrum für Neurodegenerative Erkrankungen e.V., Sigmund-Freud-Strasse 27, 53127, Bonn, Germany. .,Department of Neurology, Rheinische Friedrich-Wilhelms-Universität, 53127, Bonn, Germany.
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Sengupta I, Bhate SH, Das R, Udgaonkar JB. Salt-Mediated Oligomerization of the Mouse Prion Protein Monitored by Real-Time NMR. J Mol Biol 2017; 429:1852-1872. [DOI: 10.1016/j.jmb.2017.05.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 05/05/2017] [Accepted: 05/07/2017] [Indexed: 12/11/2022]
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50
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Cheng CJ, Koldsø H, Van der Kamp MW, Schiøtt B, Daggett V. Simulations of membrane-bound diglycosylated human prion protein reveal potential protective mechanisms against misfolding. J Neurochem 2017; 142:171-182. [PMID: 28407243 DOI: 10.1111/jnc.14044] [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: 02/07/2017] [Revised: 03/28/2017] [Accepted: 03/28/2017] [Indexed: 01/06/2023]
Abstract
Prion diseases are associated with the misfolding of the prion protein (PrP) from its normal cellular form (PrPC ) to its infectious scrapie form (PrPSc ). Post-translational modifications in PrP in vivo can play an important role in modulating the process of misfolding. To gain more insight into the effects of post-translational modifications in PrP structure and dynamics and to test the hypothesis that such modifications can interact with the protein, we have performed molecular dynamics simulations of diglycosylated human PrPC bound to a lipid bilayer via a glycophosphatidylinositol anchor. Multiple simulations were performed at three different pH ranges to explore pH effects on structure and dynamics. In contrast to simulations of protein-only PrPC , no large effects were observed upon lowering the pH of the system. The protein tilted toward the membrane surface in all of the simulations and the putative PrPSc oligomerization sites became inaccessible, thereby offering a possible protective mechanism against PrPSc -induced misfolding of PrPC .
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Affiliation(s)
- Chin Jung Cheng
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Heidi Koldsø
- Department of Bioengineering, University of Washington, Seattle, Washington, USA.,Department of Chemistry, inSPIN and iNANO Centers, Aarhus University, Aarhus C, Denmark
| | - Marc W Van der Kamp
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Birgit Schiøtt
- Department of Chemistry, inSPIN and iNANO Centers, Aarhus University, Aarhus C, Denmark
| | - Valerie Daggett
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
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