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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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Shepherd CE, Affleck AJ, Bahar AY, Carew-Jones F, Gregory G, Small DH, Halliday GM. Alzheimer's amyloid-β and tau protein accumulation is associated with decreased expression of the LDL receptor-associated protein in human brain tissue. Brain Behav 2020; 10:e01672. [PMID: 32484608 PMCID: PMC7375106 DOI: 10.1002/brb3.1672] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 04/04/2020] [Accepted: 05/04/2020] [Indexed: 11/06/2022] Open
Abstract
INTRODUCTION One of the major neuropathological features of Alzheimer's disease (AD) is the accumulation of amyloid-β (Aβ) protein in the brain. Evidence suggests that the low-density lipoprotein receptor-associated protein (RAP) binds strongly to Aβ and enhances its cellular uptake and that decreased RAP expression correlates with increased Aβ production in animal models of AD. METHODS The current study examined whether RAP levels change in AD human brain tissue and whether they are related to the amount of AD pathology. RAP and NeuN levels were determined by Western blot, while low-density lipoprotein receptor-related protein 1 (LRP1), tau and Aβ levels were determined by ELISA in the temporal cortex of 17 AD and 16 control cases. RESULTS An increase in total Aβ and insoluble and soluble tau protein was observed in AD brain tissue. In contrast, RAP levels were significantly decreased in AD brain tissue compared to controls. Correlation analysis revealed that levels of RAP correlated with both total Aβ and soluble and insoluble tau levels. Neither LRP1 nor NeuN levels were significantly altered in AD brain tissue homogenates and did not correlate with Aβ or tau protein levels. CONCLUSION Reduction in RAP may contribute to the accumulation and aggregation of Aβ in the AD brain.
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Affiliation(s)
- Claire E Shepherd
- Neuroscience Research Australia, Randwick, Sydney, NSW, Australia.,University of New South Wales, Randwick, Sydney, NSW, Australia
| | - Andrew J Affleck
- Neuroscience Research Australia, Randwick, Sydney, NSW, Australia.,University of New South Wales, Randwick, Sydney, NSW, Australia
| | - Anita Y Bahar
- Neuroscience Research Australia, Randwick, Sydney, NSW, Australia
| | - Francine Carew-Jones
- Neuroscience Research Australia, Randwick, Sydney, NSW, Australia.,University of New South Wales, Randwick, Sydney, NSW, Australia
| | - Gillian Gregory
- Neuroscience Research Australia, Randwick, Sydney, NSW, Australia
| | - David H Small
- Menzies Research Institute, University of Tasmania, Hobart, TAS, Australia
| | - Glenda M Halliday
- Neuroscience Research Australia, Randwick, Sydney, NSW, Australia.,University of New South Wales, Randwick, Sydney, NSW, Australia.,Brain and Mind Centre, University of Sydney, Sydney, NSW, Australia
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Zhao G, Dong X, Sun Y. Self-Assembled Curcumin-Poly(carboxybetaine methacrylate) Conjugates: Potent Nano-Inhibitors against Amyloid β-Protein Fibrillogenesis and Cytotoxicity. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:1846-1857. [PMID: 30134656 DOI: 10.1021/acs.langmuir.8b01921] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Fibrillogenesis of amyloid β-protein (Aβ) is a pathological hallmark of Alzheimer's disease, so inhibition of Aβ aggregation is considered as an important strategy for the precaution and treatment of AD. Curcumin (Cur) has been recognized as an effective inhibitor of Aβ fibrillogenesis, but its potential application is limited by its poor bioavailability. Herein, we proposed to conjugate Cur to a zwitterionic polymer, poly(carboxybetaine methacrylate) (pCB), and synthesized three Cur@pCB conjugates of different degrees of substitution (DS, 1.9-2.9). Cur@pCB conjugates self-assembled into nanogels of 120-190 nm. The inhibition effects of Cur@pCB conjugates on the fibrillation and cytotoxicity of Aβ42 was investigated by extensive biophysical and biological analyses. Thioflavin T fluorescence assays and atomic force microscopic observations revealed that the Cur@pCB conjugates were much more efficient than molecular curcumin on inhibiting Aβ42 fibrillation, and cytotoxicity assays also indicated the same tendency. Of the three conjugates, Cur1@pCB of the lowest DS (1.97) exhibited the best performance; 5 μM Cur1@pCB functioned similarly with 25 μM free curcumin. Moreover, 5 μM Cur1@pCB increased the cell viability by 43% but free curcumin at the same concentration showed little effect. It is considered that the highly hydrated state of the zwitterionic polymers resulted in the superiority of Cur@pCB over free curcumin. Namely, the dense hydration layer on the conjugates strongly stabilized the bound Aβ on curcumin anchored on the polymer, suppressing the conformational transition of the protein to β-sheet-rich structures. This was demonstrated by circular dichroism spectroscopy, in which Cur1@pCB was proven to be the strongest in the three conjugates. The research has thus revealed a new function of zwitterionic polymer pCBMA and provided new insights into the development of more potent nanoinhibitors for suppressing Aβ fibrillogenesis and cytotoxicity.
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Affiliation(s)
- Guangfu Zhao
- Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering of the Ministry of Education, School of Chemical Engineering and Technology , Tianjin University , Tianjin 300072 , China
| | - Xiaoyan Dong
- Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering of the Ministry of Education, School of Chemical Engineering and Technology , Tianjin University , Tianjin 300072 , China
| | - Yan Sun
- Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering of the Ministry of Education, School of Chemical Engineering and Technology , Tianjin University , Tianjin 300072 , China
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d'Uscio LV, He T, Katusic ZS. Expression and Processing of Amyloid Precursor Protein in Vascular Endothelium. Physiology (Bethesda) 2017; 32:20-32. [PMID: 27927802 DOI: 10.1152/physiol.00021.2016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Amyloid precursor protein (APP) is evolutionary conserved protein expressed in endothelial cells of cerebral and peripheral arteries. In this review, we discuss mechanisms responsible for expression and proteolytic cleavage of APP in endothelial cells. We focus on physiological and pathological implications of APP expression in vascular endothelium.
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Affiliation(s)
- Livius V d'Uscio
- Departments of Anesthesiology and Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Tongrong He
- Departments of Anesthesiology and Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Zvonimir S Katusic
- Departments of Anesthesiology and Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota
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Xie B, Li X, Dong XY, Sun Y. Insight into the inhibition effect of acidulated serum albumin on amyloid β-protein fibrillogenesis and cytotoxicity. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:9789-9796. [PMID: 25083748 DOI: 10.1021/la5025197] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Alzheimer's disease (AD) is the most prevalent form of dementia, and aggregation of amyloid β-proteins (Aβ) into soluble oligomers and fibrils has been implicated in the pathogenesis of AD. Herein we developed acidulated serum albumin for the inhibition of Aβ42 fibrillogenesis. Bovine serum albumin (BSA) was modified with diglycolic anhydride, leading to the coupling of 14.5 more negative charges (carboxyl groups) on average on each protein surface. The acidulated BSA (A-BSA) was characterized and confirmed to keep the tertiary structure and stability of BSA. Extensive biophysical and biological analyses showed that A-BSA significantly inhibited Aβ42 fibrillogenesis and mitigated amyloid cytotoxicity. As compared to the Aβ42-treated group (cell viability, 50%), the cell viability increased to 88% by the addition of equimolar A-BSA. The inhibitory effect was remarkably higher than that of BSA at the same concentration. On the basis of the experimental findings, a mechanistic model was proposed. The model considers that Aβ42 is bound to the A-BSA surface by hydrophobic interactions, but the widely distributed negative charges on the A-BSA surface give rise to electrostatic repulsions to the bound Aβ42 that is also negatively charged. The two well-balanced opposite forces make Aβ42 adopt extended conformations instead of the β-sheet structure that is necessary for the on-pathway fibrillogenesis, even when the protein is released off the surface. Thus, A-BSA greatly slows down the fibrillation and changes the fibrillogenesis pathway, leading to the formation of less toxic aggregates. The findings and the mechanistic model offer new insights into the development of more potent inhibitors of Aβ fibrillogenesis and cytotoxicity.
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Affiliation(s)
- Baolong Xie
- Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University , Tianjin 300072, China
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Fujiyoshi M, Tachikawa M, Ohtsuki S, Ito S, Uchida Y, Akanuma SI, Kamiie J, Hashimoto T, Hosoya KI, Iwatsubo T, Terasaki T. Amyloid-β peptide(1-40) elimination from cerebrospinal fluid involves low-density lipoprotein receptor-related protein 1 at the blood-cerebrospinal fluid barrier. J Neurochem 2011; 118:407-15. [PMID: 21585370 DOI: 10.1111/j.1471-4159.2011.07311.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Amyloid-β peptide (Aβ) concentration in CSF is potentially a diagnostic and therapeutic target for Alzheimer's disease (AD). The purpose of this study was to clarify the elimination mechanism of human Aβ(1-40) [hAβ (1-40)] from CSF. After intracerebroventricular (ICV) administration, [(125) I]hAβ(1-40) was eliminated from the rat CSF with a half-life of 17.3 min. The elimination of [(125) I]hAβ(1-40) was significantly inhibited by human receptor-associated protein (RAP) and the elimination was attenuated in either anti-low-density lipoprotein receptor-related protein (LRP)1 antibody-treated or RAP-deficient mice, suggesting that a member(s) of the low-density lipoprotein receptor gene family is involved in the elimination of hAβ(1-40) from CSF. The amounts of LRP1 and LRP2 proteins were determined by means of liquid chromatography-tandem mass spectrometry, and the LRP1 content in rat choroid plexus was determined to be 3.7 fmol/μg protein, whereas the LRP2 content was below the detection limit (<0.2 fmol/μg protein). Conditionally, immortalized rat choroid plexus epithelial cells exhibited predominant apical-to-basal and apical-to-cell transport of [(125) I]hAβ(1-40). These results indicated that hAβ(1-40) is actively eliminated from CSF and this process is at least partly mediated by LRP1 expressed at choroid plexus epithelial cells, which therefore play a role in determining CSF concentrations of hAβ(1-40).
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Affiliation(s)
- Masachika Fujiyoshi
- Division of Membrane Transport and Drug Targeting, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
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Chiu WT, Shen SC, Yang LY, Chow JM, Wu CY, Chen YC. Inhibition of HSP90-dependent telomerase activity in amyloid β-induced apoptosis of cerebral endothelial cells. J Cell Physiol 2011; 226:2041-51. [DOI: 10.1002/jcp.22536] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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