scholarly journals Quercetin Disaggregates Prion Fibrils and Decreases Fibril-Induced Cytotoxicity and Oxidative Stress

Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1081
Author(s):  
Kun-Hua Yu ◽  
Cheng-I Lee
Keyword(s):  
Oxidative Stress ◽  
Prion Protein ◽  
Amyloid Fibrils ◽  
Neuroblastoma Cells ◽  
Amyloid Β ◽  
Transmissible Spongiform Encephalopathies ◽  
Amyloid Β Peptide ◽  
Hemolysis Assay ◽  
Spongiform Encephalopathies

Transmissible spongiform encephalopathies (TSEs) are fatal neurodegenerative diseases caused by misfolding and aggregation of prion protein (PrP). Previous studies have demonstrated that quercetin can disaggregate some amyloid fibrils, such as amyloid β peptide (Aβ) and α-synuclein. However, the disaggregating ability is unclear in PrP fibrils. In this study, we examined the amyloid fibril-disaggregating activity of quercetin on mouse prion protein (moPrP) and characterized quercetin-bound moPrP fibrils by imaging, proteinase resistance, hemolysis assay, cell viability, and cellular oxidative stress measurements. The results showed that quercetin treatment can disaggregate moPrP fibrils and lead to the formation of the proteinase-sensitive amorphous aggregates. Furthermore, quercetin-bound fibrils can reduce the membrane disruption of erythrocytes. Consequently, quercetin-bound fibrils cause less oxidative stress, and are less cytotoxic to neuroblastoma cells. The role of quercetin is distinct from the typical function of antiamyloidogenic drugs that inhibit the formation of amyloid fibrils. This study provides a solution for the development of antiamyloidogenic therapy.

scholarly journals Self-Replication of Prion Protein Fragment 89-230 Amyloid Fibrils Accelerated by Prion Protein Fragment 107-143 Aggregates

2020 ◽  
Vol 21 (19) ◽  
pp. 7410
Author(s):  
Tomas Sneideris ◽  
Mantas Ziaunys ◽  
Brett K.-Y. Chu ◽  
Rita P.-Y. Chen ◽  
Vytautas Smirnovas
Keyword(s):  
Prion Protein ◽  
Disease Transmission ◽  
Amyloid Fibrils ◽  
The Self ◽  
Transmissible Spongiform Encephalopathies ◽  
Protein Fragment ◽  
Spongiform Encephalopathies ◽  
Amyloid Fibril Formation ◽  
Amyloid Aggregates ◽  
Self Replication

Prion protein amyloid aggregates are associated with infectious neurodegenerative diseases, known as transmissible spongiform encephalopathies. Self-replication of amyloid structures by refolding of native protein molecules is the probable mechanism of disease transmission. Amyloid fibril formation and self-replication can be affected by many different factors, including other amyloid proteins and peptides. Mouse prion protein fragments 107-143 (PrP(107-143)) and 89-230 (PrP(89-230)) can form amyloid fibrils. β-sheet core in PrP(89-230) amyloid fibrils is limited to residues ∼160–220 with unstructured N-terminus. We employed chemical kinetics tools, atomic force microscopy and Fourier-transform infrared spectroscopy, to investigate the effects of mouse prion protein fragment 107-143 fibrils on the aggregation of PrP(89-230). The data suggest that amyloid aggregates of a short prion-derived peptide are not able to seed PrP(89-230) aggregation; however, they accelerate the self-replication of PrP(89-230) amyloid fibrils. We conclude that PrP(107-143) fibrils could facilitate the self-replication of PrP(89-230) amyloid fibrils in several possible ways, and that this process deserves more attention as it may play an important role in amyloid propagation.

scholarly journals Quinoline Derivatives Are Therapeutic Candidates for Transmissible Spongiform Encephalopathies

2004 ◽  
Vol 78 (3) ◽  
pp. 1281-1288 ◽  
Author(s):  
Ikuko Murakami-Kubo ◽  
Katsumi Doh-ura ◽  
Kensuke Ishikawa ◽  
Satoshi Kawatake ◽  
Kensuke Sasaki ◽  
...  
Keyword(s):  
Incubation Period ◽  
Prion Protein ◽  
Neuroblastoma Cells ◽  
Transmissible Spongiform Encephalopathies ◽  
Side Chain ◽  
Spongiform Encephalopathy ◽  
Quinoline Derivatives ◽  
Quinoline Ring ◽  
Spongiform Encephalopathies ◽  
Dose Ranging

ABSTRACT We previously reported that quinacrine inhibited the formation of an abnormal prion protein (PrPres), a key molecule in the pathogenesis of transmissible spongiform encephalopathy, or prion disease, in scrapie-infected neuroblastoma cells. To elucidate the structural aspects of its inhibiting action, various chemicals with a quinoline ring were screened in the present study. Assays of the scrapie-infected neuroblastoma cells revealed that chemicals with a side chain containing a quinuclidine ring at the 4 position of a quinoline ring (represented by quinine) inhibited the PrPres formation at a 50% inhibitory dose ranging from 10−1 to 101 μM. On the other hand, chemicals with a side chain at the 2 position of a quinoline ring (represented by 2,2′-biquinoline) more effectively inhibited the PrPres formation at a 50% inhibitory dose ranging from 10−3 to 10−1 μM. A metabolic labeling study revealed that the action of quinine or biquinoline was not due to any alteration in the biosynthesis or turnover of normal prion protein, whereas surface plasmon resonance analysis showed a strong binding affinity of biquinoline with a recombinant prion protein. In vivo studies revealed that 4-week intraventricular infusion of quinine or biquinoline was effective in prolonging the incubation period in experimental mouse models of intracerebral infection. The findings suggest that quinoline derivatives with a nitrogen-containing side chain have the potential of both inhibiting PrPres formation in vitro and prolonging the incubation period of infected animals. These chemicals are new candidates for therapeutic drugs for use in the treatment of transmissible spongiform encephalopathies.

scholarly journals Sulphated glycosaminoglycans prevent the neurotoxicity of a human prion protein fragment

1998 ◽  
Vol 335 (2) ◽  
pp. 369-374 ◽  
Author(s):  
Mar PÉREZ ◽  
Francisco WANDOSELL ◽  
Camilo COLAÇO ◽  
Jesús AVILA
Keyword(s):  
Prion Protein ◽  
Amyloid Fibrils ◽  
Transmissible Spongiform Encephalopathies ◽  
Therapeutic Effects ◽  
Protein Fragment ◽  
Spongiform Encephalopathies ◽  
Sulphated Polysaccharides ◽  
Human Prion Protein ◽  
Sulphated Glycosaminoglycans

Although a number of features distinguish the disease isoform of the prion protein (PrPSc) from its normal cellular counterpart (PrPC) in the transmissible spongiform encephalopathies (TSEs), the neuropathogenesis of these diseases remains an enigma. The amyloid fibrils formed by fragments of human PrP have, however, been shown to be directly neurotoxic in vitro. We show here that sulphated polysaccharides (heparin, keratan and chondroitin) inhibit the neurotoxicity of these amyloid fibrils and this appears to be mediated via inhibition of the polymerization of the PrP peptide into fibrils. This provides a rationale for the therapeutic effects of sulphated polysaccharides and suggests a rapid in vitro functional screen for TSE therapeutics.

scholarly journals The role of mitochondria-targeted antioxidant MitoQ in neurodegenerative disease

2018 ◽  
pp. 1-8
Author(s):  
Linlin Zhang ◽  
Aurelio Reyes ◽  
Xiangdong Wang
Keyword(s):  
Oxidative Stress ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Neurodegenerative Diseases ◽  
Mitochondrial Dysfunction ◽  
Neurodegenerative Disease ◽  
Amyloid Β ◽  
Amyloid Β Peptide ◽  
And Oxidative Stress

Abstract: The discovery of charged molecules being able to cross the mitochondrial membrane has prompted many scholars to exploit this idea to find a way of preventing or slowing down aging. In this paper, we will focus on mitochondriatargeted antioxidants, which are cationic derivatives of plastoquinone, and in particular on the mitochondria-targeted antioxidant therapy of neurodegenerative diseases. It is well known that the accumulation of amyloid-β peptide (Aβ) in mitochondria and its related mitochondrial dysfunction are critical signatures of Alzheimer’ s disease (AD). In another neurodegenerative disease, Parkinson’s disease (PD), the loss of dopaminergic neurons in the substantia nigra and the production of Lewy bodies are among their pathological features. Pathogenesis of Parkinson’s disease and Alzheimer’s disease has been frequently linked to mitochondrial dysfunction and oxidative stress. Recent studies show that MitoQ, a mitochondria-targeted antioxidant, may possess therapeutic potential for Aβ-related and oxidative stress-associated neurodegenerative diseases, especially AD. Although MitoQ has been developed to the stage of clinical trials in PD, its true clinical effect still need further verification. This review aims to discuss the role of mitochondrial pathology in neurodegenerative diseases, as well as the recent development of mitochondrial targeted antioxidants as a potential treatment for these diseases by removing excess oxygen free radicals and inhibiting lipid peroxidation in order to improve mitochondrial function.  

scholarly journals Structural Consequences of Copper Binding to the Prion Protein

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 770 ◽  
Author(s):  
Giulia Salzano ◽  
Gabriele Giachin ◽  
Giuseppe Legname
Keyword(s):  
Prion Protein ◽  
Animal Species ◽  
State Of The Art ◽  
Copper Ions ◽  
Cellular Prion Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Copper Binding ◽  
Spongiform Encephalopathies ◽  
And Function

Prion, or PrPSc, is the pathological isoform of the cellular prion protein (PrPC) and it is the etiological agent of transmissible spongiform encephalopathies (TSE) affecting humans and animal species. The most relevant function of PrPC is its ability to bind copper ions through its flexible N-terminal moiety. This review includes an overview of the structure and function of PrPC with a focus on its ability to bind copper ions. The state-of-the-art of the role of copper in both PrPC physiology and in prion pathogenesis is also discussed. Finally, we describe the structural consequences of copper binding to the PrPC structure.

scholarly journals Toxicological Evaluation of Anti-Scrapie Trimethoxychalcones and Oxadiazoles

2015 ◽  
Vol 87 (2 suppl) ◽  
pp. 1421-1434 ◽  
Author(s):  
CLAUDIA P. FIGUEIREDO ◽  
NATALIA C. FERREIRA ◽  
GISELLE F. PASSOS ◽  
ROBSON DA COSTA ◽  
FERNANDA S. NEVES ◽  
...  
Keyword(s):  
Prion Protein ◽  
Aromatic Compounds ◽  
Prion Diseases ◽  
Intraperitoneal Administration ◽  
Neuroblastoma Cells ◽  
Cellular Prion Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Toxicological Evaluation ◽  
Spongiform Encephalopathies

An altered form of the cellular prion protein, the PrPScor PrPRes, is implicated in the occurrence of the still untreatable transmissible spongiform encephalopathies. We have previously synthesized and characterized aromatic compounds that inhibit protease-resistant prion protein (PrPRes) accumulation in scrapie-infected cells. These compounds belong to different chemical classes, including acylhydrazones, chalcones and oxadiazoles. Some of the active compounds were non-toxic to neuroblastoma cells in culture and seem to possess drugable properties, since they are in agreement with the Lipinski´s rule of 5 and present desirable pharmacokinetic profiles as predicted in silico. Before the evaluation of the in vivo efficacy of the aromatic compounds in scrapie-infected mice, safety assessment in healthy mice is needed. Here we used Swiss mice to evaluate the acute toxicity profile of the six most promising anti-prionic compounds, the 2,4,5-trimethoxychalcones (J1, J8, J20 and J35) and the 1,3,4-oxadiazoles (Y13 and Y17). One single oral administration (300 mg/kg) of J1, J8, J20, J35, Y13 and Y17 or repeated intraperitoneal administration (10 mg/kg, 3 times a week, for 4 weeks) of J1, J8 and J35, did not elicit toxicity in mice. We strongly believe that the investigated trimethoxychalcones and oxadiazoles are interesting compounds to be further analyzed in vivo against prion diseases.

The role of oxidative stress in the toxicity induced by amyloid β-peptide in Alzheimer’s disease

2000 ◽  
Vol 62 (6) ◽  
pp. 633-648 ◽  
Author(s):  
Soledad Miranda ◽  
Carlos Opazo ◽  
Luis F Larrondo ◽  
Francisco J Muñoz ◽  
Francisca Ruiz ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Β ◽  
Amyloid Β Peptide
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