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Regmi D, Shen F, Stanic A, Islam M, Du D. Effect of phospholipid liposomes on prion fragment (106-128) amyloid formation. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184199. [PMID: 37454869 DOI: 10.1016/j.bbamem.2023.184199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 06/08/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Misfolding and aggregation of cellular prion protein (PrPc) is a major molecular process involved in the pathogenesis of prion diseases. Here, we studied the aggregation properties of a prion fragment peptide PrP(106-128). The results show that the peptide aggregates in a concentration-dependent manner in an aqueous solution and that the aggregation is sensitive to pH and the preformed amyloid seeds. Furthermore, we show that the zwitterionic POPC liposomes moderately inhibit the aggregation of PrP(106-128), whereas POPC/cholesterol (8:2) vesicles facilitate peptide aggregation likely due to the increase of the lipid packing order and membrane rigidity in the presence of cholesterol. In addition, anionic lipid vesicles of POPG and POPG/cholesterol above a certain concentration accelerate the aggregation of the peptide remarkably. The strong electrostatic interactions between the N-terminal region of the peptide and POPG may constrain the conformational plasticity of the peptide, preventing insertion of the peptide into the inner side of the membrane and thus promoting fibrillation on the membrane surface. The results suggest that the charge properties of the membrane, the composition of the liposomes, and the rigidity of lipid packing are critical in determining peptide adsorption on the membrane surface and the efficiency of the membrane in catalyzing peptide oligomeric nucleation and amyloid formation. The peptide could be used as an improved model molecule to investigate the mechanistic role of the crucial regions of PrP in aggregation in a membrane-rich environment and to screen effective inhibitors to block key interactions between these regions and membranes for preventing PrP aggregation.
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Affiliation(s)
- Deepika Regmi
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Fengyun Shen
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Aleksander Stanic
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Majedul Islam
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Deguo Du
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL 33431, USA.
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2
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Yang D, Li J, Li Z, Zhao M, Wang D, Sun Z, Wen P, Gou F, Dai Y, Ji Y, Li W, Zhao D, Yang L. Cardiolipin externalization mediates prion protein (PrP) peptide 106-126-associated mitophagy and mitochondrial dysfunction. Front Mol Neurosci 2023; 16:1163981. [PMID: 37333615 PMCID: PMC10272765 DOI: 10.3389/fnmol.2023.1163981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 05/02/2023] [Indexed: 06/20/2023] Open
Abstract
Proper mitochondrial performance is imperative for the maintenance of normal neuronal function to prevent the development of neurodegenerative diseases. Persistent accumulation of damaged mitochondria plays a role in prion disease pathogenesis, which involves a chain of events that culminate in the generation of reactive oxygen species and neuronal death. Our previous studies have demonstrated that PINK1/Parkin-mediated mitophagy induced by PrP106-126 is defective and leads to an accumulation of damaged mitochondria after PrP106-126 treatment. Externalized cardiolipin (CL), a mitochondria-specific phospholipid, has been reported to play a role in mitophagy by directly interacting with LC3II at the outer mitochondrial membrane. The involvement of CL externalization in PrP106-126-induced mitophagy and its significance in other physiological processes of N2a cells treated with PrP106-126 remain unknown. We demonstrate that the PrP106-126 peptide caused a temporal course of mitophagy in N2a cells, which gradually increased and subsequently decreased. A similar trend in CL externalization to the mitochondrial surface was seen, resulting in a gradual decrease in CL content at the cellular level. Inhibition of CL externalization by knockdown of CL synthase, responsible for de novo synthesis of CL, or phospholipid scramblase-3 and NDPK-D, responsible for CL translocation to the mitochondrial surface, significantly decreased PrP106-126-induced mitophagy in N2a cells. Meanwhile, the inhibition of CL redistribution significantly decreased PINK1 and DRP1 recruitment in PrP106-126 treatment but had no significant decrease in Parkin recruitment. Furthermore, the inhibition of CL externalization resulted in impaired oxidative phosphorylation and severe oxidative stress, which led to mitochondrial dysfunction. Our results indicate that CL externalization induced by PrP106-126 on N2a cells plays a positive role in the initiation of mitophagy, leading to the stabilization of mitochondrial function.
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3
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Block AJ, Bartz JC. Prion strains: shining new light on old concepts. Cell Tissue Res 2022; 392:113-133. [PMID: 35796874 DOI: 10.1007/s00441-022-03665-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 06/23/2022] [Indexed: 02/04/2023]
Abstract
Prion diseases are a group of inevitably fatal neurodegenerative disorders affecting numerous mammalian species, including humans. The existence of heritable phenotypes of disease in the natural host suggested that prions exist as distinct strains. Transmission of sheep scrapie to rodent models accelerated prion research, resulting in the isolation and characterization of numerous strains with distinct characteristics. These strains are grouped into categories based on the incubation period of disease in different strains of mice and also by how stable the strain properties were upon serial passage. These classical studies defined the host and agent parameters that affected strain properties, and, prior to the advent of the prion hypothesis, strain properties were hypothesized to be the result of mutations in a nucleic acid genome of a conventional pathogen. The development of the prion hypothesis challenged the paradigm of infectious agents, and, initially, the existence of strains was difficult to reconcile with a protein-only agent. In the decades since, much evidence has revealed how a protein-only infectious agent can perform complex biological functions. The prevailing hypothesis is that strain-specific conformations of PrPSc encode prion strain diversity. This hypothesis can provide a mechanism to explain the observed strain-specific differences in incubation period of disease, biochemical properties of PrPSc, tissue tropism, and subcellular patterns of pathology. This hypothesis also explains how prion strains mutate, evolve, and adapt to new species. These concepts are applicable to prion-like diseases such as Parkinson's and Alzheimer's disease, where evidence of strain diversity is beginning to emerge.
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Affiliation(s)
- Alyssa J Block
- Department of Medical Microbiology and Immunology, Creighton University, 2500 California Plaza, Omaha, NE, 68178, USA
| | - Jason C Bartz
- Department of Medical Microbiology and Immunology, Creighton University, 2500 California Plaza, Omaha, NE, 68178, USA.
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Tandon A, Subramani VK, Kim KK, Park SH. Interaction of Prion Peptides with DNA Structures. ACS OMEGA 2022; 7:176-186. [PMID: 35036689 PMCID: PMC8756453 DOI: 10.1021/acsomega.1c04328] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 11/09/2021] [Indexed: 06/14/2023]
Abstract
Prion protein aggregation is known to be modulated by macromolecules including nucleic acids. To clarify the role of nucleic acids in PrP pathology, we investigated the interaction between nucleic acids and the prion peptide (PrP)-a synthetic prion protein model peptide resembling a portion of the human prion protein in structure and function spanning amino acid residues 106-126. We used synthetic DNA lattices and natural DNA duplexes extracted from salmon (sDNA) bound with PrP and studied their interaction using distinct physical measurements. The formation of DNA lattices with PrP was visualized by atomic force microscopy (AFM) to investigate the influence of the PrP. PrP inhibited the growth of the double-crossover (DX) lattices significantly compared to the control peptide (CoP). We also conducted optical measurements such as ultraviolet-visible (UV-Vis), circular dichroism (CD), and Fourier transform infrared (FTIR) spectroscopies to validate the interaction between PrP and DNA immediately (D0) and after a 30-day incubation (D30) period. UV-Vis spectra showed variation in the absorbance intensities, specific for the binding of CoP and PrP to DNA. The CD analysis revealed the presence of various secondary structures, such as α-helices and β-sheets, in PrP- and PrP-bound sDNA complexes. The PrP-sDNA interaction was confirmed using FTIR by the change and shift of the absorption peak intensity and the alteration of PrP secondary structures in the presence of DNA. The cytotoxic effects of the PrP-bound sDNA complexes were assessed by a cytotoxicity assay in human neuroblastoma cells in culture. It confirmed that PrP with sDNA was less cytotoxic than CoP. This study provides new applications for DNA molecules by investigating their effect in complex with aggregated proteins. Our study unequivocally showed the beneficial effect of the interaction between DNA and the pathological prion protein. It therefore provides valuable information to exploit this effect in the development of potential therapeutics. Moreover, our work might serve as a basis for further studies investigating the role of DNA interactions with other amyloidogenic proteins.
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Affiliation(s)
- Anshula Tandon
- Department
of Physics, Sungkyunkwan University, Suwon 16419, Korea
- Sungkyunkwan
Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Korea
| | - Vinod Kumar Subramani
- Department
of Precision Medicine, School of Medicine, Sungkyunkwan University, Suwon 16419, Korea
| | - Kyeong Kyu Kim
- Sungkyunkwan
Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Korea
- Department
of Precision Medicine, School of Medicine, Sungkyunkwan University, Suwon 16419, Korea
| | - Sung Ha Park
- Department
of Physics, Sungkyunkwan University, Suwon 16419, Korea
- Sungkyunkwan
Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Korea
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5
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Broersen K. Milk Processing Affects Structure, Bioavailability and Immunogenicity of β-lactoglobulin. Foods 2020; 9:foods9070874. [PMID: 32635246 PMCID: PMC7404694 DOI: 10.3390/foods9070874] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 06/24/2020] [Accepted: 06/26/2020] [Indexed: 12/15/2022] Open
Abstract
Bovine milk is subjected to various processing steps to warrant constant quality and consumer safety. One of these steps is pasteurization, which involves the exposure of liquid milk to a high temperature for a limited amount of time. While such heating effectively ameliorates consumer safety concerns mediated by pathogenic bacteria, these conditions also have an impact on one of the main nutritional whey constituents of milk, the protein β-lactoglobulin. As a function of heating, β-lactoglobulin was shown to become increasingly prone to denaturation, aggregation, and lactose conjugation. This review discusses the implications of such heat-induced modifications on digestion and adsorption in the gastro-intestinal tract, and the responses these conformations elicit from the gastro-intestinal immune system.
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Affiliation(s)
- Kerensa Broersen
- Department of Applied Stem Cell Technologies, TechMed Centre, University of Twente, Postbus 217, 7500 AE Enschede, The Netherlands
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6
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Israeli R, Kolusheva S, Hadad U, Jelinek R. Imaging Flow Cytometry Illuminates New Dimensions of Amyloid Peptide-Membrane Interactions. Biophys J 2020; 118:1270-1278. [PMID: 32053776 PMCID: PMC7091230 DOI: 10.1016/j.bpj.2020.01.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 01/06/2020] [Accepted: 01/15/2020] [Indexed: 12/19/2022] Open
Abstract
Membrane interactions of amyloidogenic proteins constitute central determinants both in protein aggregation as well as in amyloid cytotoxicity. Most reported studies of amyloid peptide-membrane interactions have employed model membrane systems combined with application of spectroscopy methods or microscopy analysis of individual binding events. Here, we applied for the first time, to our knowledge, imaging flow cytometry for investigating interactions of representative amyloidogenic peptides, namely, the 106-126 fragment of prion protein (PrP(106-126)) and the human islet amyloid polypeptide (hIAPP), with giant lipid vesicles. Imaging flow cytometry was also applied to examine the inhibition of PrP(106-126)-membrane interactions by epigallocatechin gallate, a known modulator of amyloid peptide aggregation. We show that imaging flow cytometry provided comprehensive population-based statistical information upon morphology changes of the vesicles induced by PrP(106-126) and hIAPP. Specifically, the experiments reveal that both PrP(106-126) and hIAPP induced dramatic transformations of the vesicles, specifically disruption of the spherical shapes, reduction of vesicle circularity, lobe formation, and modulation of vesicle compactness. Interesting differences, however, were apparent between the impact of the two peptides upon the model membranes. The morphology analysis also showed that epigallocatechin gallate ameliorated vesicle disruption by PrP(106-126). Overall, this study demonstrates that imaging flow cytometry provides powerful means for disclosing population-based morphological membrane transformations induced by amyloidogenic peptides and their inhibition by aggregation modulators.
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Affiliation(s)
- Reut Israeli
- Department of Chemistry, Ben-Gurion University of the Negev, Beersheba, Israel
| | - Sofiya Kolusheva
- Department of Chemistry, Ben-Gurion University of the Negev, Beersheba, Israel; Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beersheba, Israel
| | - Uzi Hadad
- Department of Chemistry, Ben-Gurion University of the Negev, Beersheba, Israel; Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beersheba, Israel
| | - Raz Jelinek
- Department of Chemistry, Ben-Gurion University of the Negev, Beersheba, Israel; Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beersheba, Israel.
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7
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Naturally occurring cinnamic acid derivatives prevent amyloid transformation of alpha-synuclein. Biochimie 2020; 170:128-139. [DOI: 10.1016/j.biochi.2020.01.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 01/09/2020] [Indexed: 12/26/2022]
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8
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Wu W, Zhao D, Shah SZA, Zhang X, Lai M, Yang D, Wu X, Guan Z, Li J, Zhao H, Li W, Gao H, Zhou X, Qiao J, Yang L. OPA1 overexpression ameliorates mitochondrial cristae remodeling, mitochondrial dysfunction, and neuronal apoptosis in prion diseases. Cell Death Dis 2019; 10:710. [PMID: 31551424 PMCID: PMC6760175 DOI: 10.1038/s41419-019-1953-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/30/2019] [Accepted: 08/11/2019] [Indexed: 11/29/2022]
Abstract
Prion diseases caused by the cellular prion protein (PrPC) conversion into a misfolded isoform (PrPSc) are associated with multiple mitochondrial damages. We previously reported mitochondrial dynamic abnormalities and cell death in prion diseases via modulation of a variety of factors. Optic atrophy 1 (OPA1) is one of the factors that control mitochondrial fusion, mitochondrial DNA (mtDNA) maintenance, bioenergetics, and cristae integrity. In this study, we observed downregulation of OPA1 in prion disease models in vitro and in vivo, mitochondria structure damage and dysfunction, loss of mtDNA, and neuronal apoptosis. Similar mitochondria findings were seen in OPA1-silenced un-infected primary neurons. Overexpression of OPA1 not only alleviated prion-induced mitochondrial network fragmentation and mtDNA loss, decrease in intracellular ATP, increase in ADP/ATP ratio, and decrease in mitochondrial membrane potential but also protected neurons from apoptosis by suppressing the release of cytochrome c from mitochondria to cytosol and activation of the apoptotic factor, caspase 3. Our results demonstrated that overexpression of OPA1 alleviates prion-associated mitochondrial network fragmentation and cristae remodeling, mitochondrial dysfunction, mtDNA depletion, and neuronal apoptosis, suggesting that OPA1 may be a novel and effective therapeutic target for prion diseases.
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Affiliation(s)
- Wei Wu
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China.,Department of Pathophysiology, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Deming Zhao
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Syed Zahid Ali Shah
- Department of Pathology, Faculty of Veterinary Sciences, Cholistan University of Veterinary and Animal Sciences, Bahawalpur, Pakistan
| | - Xixi Zhang
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Mengyu Lai
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Dongming Yang
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xiaoqian Wu
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Zhiling Guan
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Jie Li
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Huafen Zhao
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Wen Li
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Hongli Gao
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xiangmei Zhou
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Jian Qiao
- Department of Pathophysiology, College of Veterinary Medicine, China Agricultural University, Beijing, China.
| | - Lifeng Yang
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China.
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Forloni G, Chiesa R, Bugiani O, Salmona M, Tagliavini F. Review: PrP 106-126 - 25 years after. Neuropathol Appl Neurobiol 2019; 45:430-440. [PMID: 30635947 DOI: 10.1111/nan.12538] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 12/10/2018] [Indexed: 12/14/2022]
Abstract
A quarter of a century ago, we proposed an innovative approach to study the pathogenesis of prion disease, one of the most intriguing biomedical problems that remains unresolved. The synthesis of a peptide homologous to residues 106-126 of the human prion protein (PrP106-126), a sequence present in the PrP amyloid protein of Gerstmann-Sträussler-Scheinker syndrome patients, provided a tractable tool for investigating the mechanisms of neurotoxicity. Together with several other discoveries at the beginning of the 1990s, PrP106-126 contributed to underpin the role of amyloid in the pathogenesis of protein-misfolding neurodegenerative disorders. Later, the role of oligomers on one hand and of prion-like spreading of pathology on the other further clarified mechanisms shared by different neurodegenerative conditions. Our original report on PrP106-126 neurotoxicity also highlighted a role for programmed cell death in CNS diseases. In this review, we analyse the prion research context in which PrP106-126 first appeared and the advances in our understanding of prion disease pathogenesis and therapeutic perspectives 25 years later.
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Affiliation(s)
- G Forloni
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - R Chiesa
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - O Bugiani
- Department of Biochemistry, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - M Salmona
- Department of Biochemistry, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - F Tagliavini
- Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milano, Italy
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Lai M, Yao H, Shah SZA, Wu W, Wang D, Zhao Y, Wang L, Zhou X, Zhao D, Yang L. The NLRP3-Caspase 1 Inflammasome Negatively Regulates Autophagy via TLR4-TRIF in Prion Peptide-Infected Microglia. Front Aging Neurosci 2018; 10:116. [PMID: 29720937 PMCID: PMC5915529 DOI: 10.3389/fnagi.2018.00116] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 04/03/2018] [Indexed: 12/15/2022] Open
Abstract
Prion diseases are neurodegenerative disorders characterized by the accumulation of misfolded prion protein, spongiform changes in the brain, and brain inflammation as a result of the wide-spread activation of microglia. Autophagy is a highly conserved catabolic process for the clearance of cytoplasmic components, including protein aggregates and damaged organelles; this process also eliminates pathological PrPSc as it accumulates during prion infection. The NALP3 inflammasome is a multiprotein complex that is a component of the innate immune system and is responsible for the release of pro-inflammatory cytokines. Our previous study showed that the neurotoxic prion peptide PrP106-126 induces NALP3 inflammasome activation and subsequent IL-1β release in microglia. Autophagy is involved in the regulation of the immune responses and inflammation in many diseases including neurodegenerative diseases. However, the relationship between autophagy and NALP3 inflammasome in prion diseases has not been investigated. In this study, we demonstrated that the processing and release of mature IL-1β is significantly enhanced by the inhibition of autophagy. Conversely, gene-silencing of the NALP3 inflammasome promotes autophagy. Suppression of TRIF or TLR4 by siRNA attenuated PrP106-126-induced autophagy, which is indicating that the TLR4-TRIF signaling pathway is involved in PrP106-26-induced autophagy. Caspase 1 directly cleaved TRIF to diminish TLR-4-TRIF mediated autophagy. Our findings suggest that the inhibition of autophagy by NALP3 inflammasome is probably mediated by activated Caspase-1-induced TRIF cleavage. This is the first study reporting that the NALP3 inflammasome complex negatively regulates autophagy in response to PrP106-126 stimulation in microglia, and partly explains the mechanism of autophagy inhibition by Caspase-1 in PrP106-126-induced BV2 cell activation. Our findings suggest that autophagy up-regulation and inhibition of Caspase-1 may protect against prion-induced neuroinflammation and accelerate misfolded protein degradation and are potential therapeutic approaches for prion diseases.
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Affiliation(s)
- Mengyu Lai
- National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, China Agricultural University, Beijing, China
| | - Hao Yao
- National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, China Agricultural University, Beijing, China
| | - Syed Zahid Ali Shah
- National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, China Agricultural University, Beijing, China
| | - Wei Wu
- National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, China Agricultural University, Beijing, China
| | - Di Wang
- National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, China Agricultural University, Beijing, China
| | - Ying Zhao
- National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, China Agricultural University, Beijing, China
| | - Lu Wang
- National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, China Agricultural University, Beijing, China
| | - Xiangmei Zhou
- National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, China Agricultural University, Beijing, China
| | - Deming Zhao
- National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, China Agricultural University, Beijing, China
| | - Lifeng Yang
- National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, China Agricultural University, Beijing, China
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11
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Ning L, Mu Y. Aggregation of PrP106-126 on surfaces of neutral and negatively charged membranes studied by molecular dynamics simulations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1936-1948. [PMID: 29550288 DOI: 10.1016/j.bbamem.2018.03.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 03/08/2018] [Accepted: 03/08/2018] [Indexed: 01/28/2023]
Abstract
Prion diseases are neurodegenerative disorders characterized by the aggregation of an abnormal form of prion protein. The interaction of prion protein and cellular membrane is crucial to elucidate the occurrence and development of prion diseases. Its fragment, residues 106-126, has been proven to maintain the pathological properties of misfolded prion and was used as a model peptide. In this study, explicit solvent molecular dynamics (MD) simulations were carried out to investigate the adsorption, folding and aggregation of PrP106-126 with different sizes (2-peptides, 4-peptides and 6-peptides) on the surface of both pure neutral POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) and negatively charged POPC/POPG (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol) (3:1) lipids. MD simulation results show that PrP106-126 display strong affinity with POPC/POPG but does not interact with pure POPC. The positively charged and polar residues participating hydrogen bonding with membrane promote the adsorption of PrP106-126. The presence of POPC and POPC/POPG exert limited influence on the secondary structures of PrP106-126 and random coil structures are predominant in all simulation systems. Upon the adsorption on the POPC/POPG surface, the aggregation states of PrP106-126 have been changed and more small oligomers were observed. This work provides insights into the interactions of PrP106-126 and membranes with different compositions in atomic level, which expand our understanding the role membrane plays in the development of prion diseases. This article is part of a Special Issue entitled: Protein Aggregation and Misfolding at the Cell Membrane Interface edited by Ayyalusamy Ramamoorthy.
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Affiliation(s)
- Lulu Ning
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Yuguang Mu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
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12
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Moon JH, Lee JH, Lee YJ, Park SY. Autophagy flux induced by ginsenoside-Rg3 attenuates human prion protein-mediated neurotoxicity and mitochondrial dysfunction. Oncotarget 2018; 7:85697-85708. [PMID: 27911875 PMCID: PMC5349867 DOI: 10.18632/oncotarget.13730] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 11/11/2016] [Indexed: 12/19/2022] Open
Abstract
Mitochondrial quality control is a process by which mitochondria undergo successive rounds of fusion and fission with dynamic exchange of components to segregate functional and damaged elements. Removal of mitochondrion that contains damaged components is accomplished via autophagy. In this study, we investigated whether ginsenoside Rg3, an active ingredient of the herbal medicine ginseng that is used as a tonic and restorative agent, could attenuate prion peptide, PrP (106-126)-induced neurotoxicity and mitochondrial damage. To this end, western blot and GFP-LC3B puncta assay were performed to monitor autophagy flux in neuronal cells; LC3B-II protein level was found to increase after Rg3 treatment. In addition, electron microscopy analysis showed that Rg3 enhanced autophagic vacuoles in neuronal cells. By using autophagy inhibitors wortmannin and 3-methyladenine (3MA) or autophagy protein 5 (Atg5) small interfering RNA (siRNA), we demonstrated that Rg3 could protect neurons against PrP (106-126)-induced cytotoxicity via autophagy flux. We found that Rg3 could also attenuate PrP (106-126)-induced mitochondrial damage via autophagy flux. Taken together, our results suggest that Rg3 is a possible therapeutic agent in neurodegenerative disorders, including prion diseases.
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Affiliation(s)
- Ji-Hong Moon
- Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Iksan, Jeonbuk, South Korea
| | - Ju-Hee Lee
- Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Iksan, Jeonbuk, South Korea
| | - You-Jin Lee
- Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Iksan, Jeonbuk, South Korea
| | - Sang-Youel Park
- Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Iksan, Jeonbuk, South Korea
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13
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Song Z, Zhu T, Zhou X, Barrow P, Yang W, Cui Y, Yang L, Zhao D. REST alleviates neurotoxic prion peptide-induced synaptic abnormalities, neurofibrillary degeneration and neuronal death partially via LRP6-mediated Wnt-β-catenin signaling. Oncotarget 2017; 7:12035-52. [PMID: 26919115 PMCID: PMC4914267 DOI: 10.18632/oncotarget.7640] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Accepted: 02/14/2016] [Indexed: 02/07/2023] Open
Abstract
Prion diseases are a group of infectious neurodegenerative diseases characterized by multiple neuropathological hallmarks including synaptic damage, spongiform degeneration and neuronal death. The factors and mechanisms that maintain cellular morphological integrity and protect against neurodegeneration in prion diseases are still unclear. Here we report that after stimulation with the neurotoxic PrP106-126 fragment in primary cortical neurons, REST translocates from the cytoplasm to the nucleus and protects neurons from harmful effects of PrP106-126. Overexpression of REST reduces pathological damage and abnormal biochemical alterations of neurons induced by PrP106-126 and maintains neuronal viability by stabilizing the level of pro-survival protein FOXO1 and inhibiting the permeability of the mitochondrial outer membrane, release of cytochrome c from mitochondria to cytoplasm and the activation of Capase3. Conversely, knockdown of REST exacerbates morphological damage and inhibits the expression of FOXO1. Additionally, by overexpression or knockdown of LRP6, we further show that LRP6-mediated Wnt-β-catenin signaling partly regulates the expression of REST. Collectively, we demonstrate for the first time novel neuroprotective function of REST in prion diseases and hypothesise that the LRP6-Wnt-β-catenin/REST signaling plays critical and collaborative roles in neuroprotection. This signaling of neuronal survival regulation could be explored as a viable therapeutic target for prion diseases and associated neurodegenerative diseases.
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Affiliation(s)
- Zhiqi Song
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Ting Zhu
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xiangmei Zhou
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Paul Barrow
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, UK
| | - Wei Yang
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yongyong Cui
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Lifeng Yang
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Deming Zhao
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
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14
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Megra BW, Eugenin EA, Berman JW. The Role of Shed PrP c in the Neuropathogenesis of HIV Infection. THE JOURNAL OF IMMUNOLOGY 2017; 199:224-232. [PMID: 28533442 DOI: 10.4049/jimmunol.1601041] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 04/21/2017] [Indexed: 01/02/2023]
Abstract
HIV-1 enters the CNS soon after peripheral infection and causes chronic neuroinflammation and neuronal damage that leads to cognitive impairment in 40-70% of HIV-infected people. The nonpathogenic cellular isoform of the human prion protein (PrPc) is an adhesion molecule constitutively expressed in the CNS. Previously, our laboratory showed that shed PrPc (sPrPc) is increased in the cerebrospinal fluid of HIV-infected people with cognitive deficits as compared with infected people with no impairment. In this article, we demonstrate that CCL2 and TNF-α, inflammatory mediators that are elevated in the CNS of HIV-infected people, increase shedding of PrPc from human astrocytes by increasing the active form of the metalloprotease ADAM10. We show that the consequence of this shedding can be the production of inflammatory mediators, because treatment of astrocytes with rPrPc increased secretion of CCL2, CXCL-12, and IL-8. Supernatants from rPrPc-treated astrocytes containing factors produced in response to this treatment, but not rPrPc by itself, cause increased chemotaxis of both uninfected and HIV-infected human monocytes, suggesting a role for sPrPc in monocyte recruitment into the brain. Furthermore, we examined whether PrPc participates in glutamate uptake and found that rPrPc decreased uptake of this metabolite in astrocytes, which could lead to neurotoxicity and neuronal loss. Collectively, our data characterize mediators involved in PrPc shedding and the effect of this sPrPc on monocyte chemotaxis and glutamate uptake from astrocytes. We propose that shedding of PrPc could be a potential target for therapeutics to limit the cognitive impairment characteristic of neuroAIDS.
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Affiliation(s)
- Bezawit W Megra
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Eliseo A Eugenin
- Public Health Research Institute, Newark, NJ 07103.,Department of Microbiology and Molecular Genetics, Rutgers New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103
| | - Joan W Berman
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461; .,Department of Microbiology, Albert Einstein College of Medicine, Bronx, NY 10461; and.,Department of Immunology, Albert Einstein College of Medicine, Bronx, NY 10461
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15
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Yang W, Yang LF, Song ZQ, Shah SZA, Cui YY, Li CS, Zhao HF, Gao HL, Zhou XM, Zhao DM. PRAS40 alleviates neurotoxic prion peptide-induced apoptosis via mTOR-AKT signaling. CNS Neurosci Ther 2017; 23:416-427. [PMID: 28294542 DOI: 10.1111/cns.12685] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 02/06/2017] [Accepted: 02/07/2017] [Indexed: 01/04/2023] Open
Abstract
AIMS The proline-rich Akt substrate of 40-kDa (PRAS40) protein is a direct inhibitor of mTORC1 and an interactive linker between the Akt and mTOR pathways. The mammalian target of rapamycin (mTOR) is considered to be a central regulator of cell growth and metabolism. Several investigations have demonstrated that abnormal mTOR activity may contribute to the pathogenesis of several neurodegenerative disorders and lead to cognitive deficits. METHODS Here, we used the PrP peptide 106-126 (PrP106-126 ) in a cell model of prion diseases (also known as transmissible spongiform encephalopathies, TSEs) to investigate the mechanisms of mTOR-mediated cell death in prion diseases. RESULTS We have shown that, upon stress caused by PrP106-126 , the mTOR pathway activates and contributes to cellular apoptosis. Moreover, we demonstrated that PRAS40 down-regulates mTOR hyperactivity under stress conditions and alleviates neurotoxic prion peptide-induced apoptosis. The effect of PRAS40 on apoptosis is likely due to an mTOR/Akt signaling. CONCLUSION PRAS40 inhibits mTORC1 hyperactivation and plays a key role in protecting cells against neurotoxic prion peptide-induced apoptosis. Thus, PRAS40 is a potential therapeutic target for prion disease.
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Affiliation(s)
- Wei Yang
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China.,Hebei Institute of Animal Science and Veterinary Medicine, Baoding, China
| | - Li-Feng Yang
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
| | - Zhi-Qi Song
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
| | - Syed Zahid Ali Shah
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
| | - Yong-Yong Cui
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
| | - Chao-Si Li
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
| | - Hua-Fen Zhao
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
| | - Hong-Li Gao
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
| | - Xiang-Mei Zhou
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
| | - De-Ming Zhao
- National Animal Transmissible Spongiform Encephalopathy Laboratory and Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, China
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16
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Han S, Lee MK, Lim YB. Cell-Penetrating Cross-β Peptide Assemblies with Controlled Biodegradable Properties. Biomacromolecules 2016; 18:27-35. [DOI: 10.1021/acs.biomac.6b01153] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sanghun Han
- Department of Materials Science
and Engineering, Yonsei University, Seoul 03722, Korea
| | - Mun-kyung Lee
- Department of Materials Science
and Engineering, Yonsei University, Seoul 03722, Korea
| | - Yong-beom Lim
- Department of Materials Science
and Engineering, Yonsei University, Seoul 03722, Korea
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17
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Hecel A, De Ricco R, Valensin D. Influence of membrane environments and copper ions on the structural features of amyloidogenic proteins correlated to neurodegeneration. Coord Chem Rev 2016. [DOI: 10.1016/j.ccr.2016.06.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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18
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EGCG-mediated autophagy flux has a neuroprotection effect via a class III histone deacetylase in primary neuron cells. Oncotarget 2016; 6:9701-17. [PMID: 25991666 PMCID: PMC4496391 DOI: 10.18632/oncotarget.3832] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 03/26/2015] [Indexed: 01/04/2023] Open
Abstract
Prion diseases caused by aggregated misfolded prion protein (PrP) are transmissible neurodegenerative disorders that occur in both humans and animals. Epigallocatechin-3-gallate (EGCG) has preventive effects on prion disease; however, the mechanisms related to preventing prion diseases are unclear. We investigated whether EGCG, the main polyphenol in green tea, prevents neuron cell damage induced by the human prion protein. We also studied the neuroprotective mechanisms and proper signals mediated by EGCG. The results showed that EGCG protects the neuronal cells against human prion protein-induced damage through inhibiting Bax and cytochrome c translocation and autophagic pathways by increasing LC3-II and reducing and blocking p62 by using ATG5 small interfering (si) RNA and autophagy inhibitors. We further demonstrated that the neuroprotective effects of EGCG were exhibited by a class III histone deacetylase; sirt1 activation and the neuroprotective effects attenuated by sirt1 inactivation using sirt1 siRNA and sirtinol. We demonstrated that EGCG activated the autophagic pathways by inducing sirt1, and had protective effects against human prion protein-induced neuronal cell toxicity. These results suggest that EGCG may be a therapeutic agent for treatment of neurodegenerative disorders including prion diseases.
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19
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Zhu D, Zhao C, Wang X, Wang W, Wang B, Du W. Roles of DMSO-type ruthenium complexes in disaggregation of prion neuropeptide PrP106–126. RSC Adv 2016. [DOI: 10.1039/c5ra21523d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
DMSO-type ruthenium complexes with aromatic ligands disaggregate the mature PrP106–126 fibrilsviametal coordination and hydrophobic interaction.
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Affiliation(s)
- Dengsen Zhu
- Department of Chemistry
- Renmin University of China
- Beijing
- China
| | - Cong Zhao
- Department of Chemistry
- Renmin University of China
- Beijing
- China
| | - Xuesong Wang
- Department of Chemistry
- Renmin University of China
- Beijing
- China
| | - Wenji Wang
- Department of Chemistry
- Renmin University of China
- Beijing
- China
| | - Baohuai Wang
- College of Chemistry and Molecular Engineering
- Peking University
- China
| | - Weihong Du
- Department of Chemistry
- Renmin University of China
- Beijing
- China
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20
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Membrane-mediated amyloid formation of PrP 106-126: A kinetic study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015. [PMID: 26215743 DOI: 10.1016/j.bbamem.2015.07.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
PrP 106-126 conserves the pathogenic and physicochemical properties of the Scrapie isoform of the prion protein. PrP 106-126 and other amyloidal proteins are capable of inducing ion permeability through cell membranes, and this property may represent the common primary mechanism of pathogenesis in the amyloid-related degenerative diseases. However, for many amyloidal proteins, despite numerous phenomenological observations of their interactions with membranes, it has been difficult to determine the molecular mechanisms by which the proteins cause ion permeability. One approach that has not been undertaken is the kinetic study of protein-membrane interactions. We found that the reaction time constant of the interaction between PrP 106-126 and membranes is suitable for such studies. The kinetic experiment with giant lipid vesicles showed that the membrane area first increased by peptide binding but then decreased. The membrane area decrease was coincidental with appearance of extramembranous aggregates including lipid molecules. Sometimes, the membrane area would increase again followed by another decrease. The kinetic experiment with small vesicles was monitored by circular dichroism for peptide conformation changes. The results are consistent with a molecular simulation following a simple set of well-defined rules. We deduced that at the molecular level the formation of peptide amyloids incorporated lipid molecules as part of the aggregates. Most importantly the amyloid aggregates desorbed from the lipid bilayer, consistent with the macroscopic phenomena observed with giant vesicles. Thus we conclude that the main effect of membrane-mediated amyloid formation is extraction of lipid molecules from the membrane. We discuss the likelihood of this effect on membrane ion permeability.
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21
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Ning L, Pan D, Zhang Y, Wang S, Liu H, Yao X. Effects of the Pathogenic Mutation A117V and the Protective Mutation H111S on the Folding and Aggregation of PrP106-126: Insights from Replica Exchange Molecular Dynamics Simulations. PLoS One 2015; 10:e0125899. [PMID: 25993001 PMCID: PMC4439087 DOI: 10.1371/journal.pone.0125899] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 03/24/2015] [Indexed: 11/19/2022] Open
Abstract
The fragment 106-126 of prion protein exhibits similar properties to full-length prion. Experiments have shown that the A117V mutation enhances the aggregation of PrP106-126, while the H111S mutation abolishes the assembly. However, the mechanism of the change in the aggregation behavior of PrP106-126 upon the two mutations is not fully understood. In this study, replica exchange molecular dynamics simulations were performed to investigate the conformational ensemble of the WT PrP106-126 and its two mutants A117V and H111S. The obtained results indicate that the three species are all intrinsically disordered but they have distinct morphological differences. The A117V mutant has a higher propensity to form β-hairpin structures than the WT, while the H111S mutant has a higher population of helical structures. Furthermore, the A117V mutation increases the hydrophobic solvent accessible surface areas of PrP106-126 and the H111S mutation reduces the exposure of hydrophobic residues. It can be concluded that the difference in populations of β-hairpin structures and the change of hydrophobic solvent accessible areas may induce the different aggregation behaviors of the A117V and the H111S mutated PrP106-126. Understanding why the two mutations have contrary effects on the aggregation of PrP106-126 is very meaningful for further elucidation of the mechanism underlying aggregation and design of inhibitor against aggregation process.
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Affiliation(s)
- Lulu Ning
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, China
| | - Dabo Pan
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, China
- School of pharmaceutical technology, Qiandongnan National Polytechnic, Kaili, China
| | - Yan Zhang
- School of Pharmacy, Lanzhou University, Lanzhou, China
| | - Shaopeng Wang
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, China
| | - Huanxiang Liu
- School of Pharmacy, Lanzhou University, Lanzhou, China
- * E-mail: (HL); (XY)
| | - Xiaojun Yao
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, China
- State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa, Macau, China
- * E-mail: (HL); (XY)
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22
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Death Receptor 6 and Caspase-6 Regulate Prion Peptide-Induced Axonal Degeneration in Rat Spinal Neurons. J Mol Neurosci 2015; 56:966-976. [DOI: 10.1007/s12031-015-0562-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 04/01/2015] [Indexed: 01/12/2023]
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23
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Wang X, Zhu D, Zhao C, He L, Du W. Inhibitory effects of NAMI-A-like ruthenium complexes on prion neuropeptide fibril formation. Metallomics 2015; 7:837-46. [PMID: 25856332 DOI: 10.1039/c5mt00029g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Prion diseases are a group of infectious and fatal neurodegenerative disorders caused by the conformational conversion of a cellular prion protein (PrP) into its abnormal isoform PrP(Sc). PrP106-126 resembles PrP(Sc) in terms of physicochemical and biological characteristics and is used as a common model for the treatment of prion diseases. Inhibitory effects on fibril formation and neurotoxicity of the prion neuropeptide PrP106-126 have been investigated using metal complexes as potential inhibitors. Nevertheless, the binding mechanism between metal complexes and the peptide remains unclear. The present study is focused on the interaction of PrP106-126 with NAMI-A and NAMI-A-like ruthenium complexes, including KP418, KP1019, and KP1019-2. Results demonstrated that these ruthenium complexes could bind to PrP106-126 in a distinctive binding mode through electrostatic and hydrophobic interactions. NAMI-A-like ruthenium complexes can also effectively inhibit the aggregation and fibril formation of PrP106-126. The complex KP1019 demonstrated the optimal inhibitory ability upon peptide aggregation, and cytotoxicity because of its large aromatic ligand contribution. The studied complexes could also regulate the copper redox chemistry of PrP106-126 and effectually inhibit the formation of reactive oxygen species. Given these findings, ruthenium complexes with relatively low cellular toxicity may be used to develop potential pharmaceutical products against prion diseases.
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Affiliation(s)
- Xuesong Wang
- Department of Chemistry, Renmin University of China, Beijing 100872, People's Republic of China.
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24
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Pathogenic prion protein fragment (PrP106-126) promotes human immunodeficiency virus type-1 infection in peripheral blood monocyte-derived macrophages. Virology 2015; 476:372-376. [PMID: 25589240 DOI: 10.1016/j.virol.2014.11.032] [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: 06/30/2014] [Revised: 08/11/2014] [Accepted: 11/16/2014] [Indexed: 11/22/2022]
Abstract
Transfusion of blood and blood products contaminated with the pathogenic form of prion protein Prp(sc), thought to be the causative agent of variant a Creutzfeldt-Jakob disease (vCJD), may result in serious consequences in recipients with a compromised immune system, for example, as seen in HIV-1 infection. In the present study, we demonstrate that treatment of peripheral blood monocyte-derived macrophages (MDM) with PrP106-126, a synthetic domain of PrP(sc) that has intrinsic functional activities related to the full-length protein, markedly increased their susceptibility to HIV-1 infection, induced cytokine secretion, and enhanced their migratory behavior in response to N-formyl-l-methionyl-l-leucyl-l-phenylalanine (fMLP). Live-cell imaging of MDM cultured in the presence of PrP106-126 showed large cell clusters indicative of cellular activation. Tyrosine kinase inhibitor STI-571, protein kinase C inhibitor K252B, and cyclin-dependent kinase inhibitor olomoucine attenuated PrP106-126-induced altered MDM functions. These findings delineate a previously undefined functional role of PrP106-126-mediated host cell response in promoting HIV-1 pathogenesis.
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25
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Ning L, Wang Q, Zheng Y, Liu H, Yao X. Effects of the A117V mutation on the folding and aggregation of palindromic sequences (PrP113–120) in prion: insights from replica exchange molecular dynamics simulations. MOLECULAR BIOSYSTEMS 2015; 11:647-55. [DOI: 10.1039/c4mb00546e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The A117V mutation enhances the aggregation propensity of the palindromic sequences in prion protein.
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Affiliation(s)
- Lulu Ning
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry
- Lanzhou University
- Lanzhou 730000
- China
| | - Qianqian Wang
- School of Pharmacy
- Lanzhou University
- Lanzhou 730000
- China
| | - Yang Zheng
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry
- Lanzhou University
- Lanzhou 730000
- China
| | - Huanxiang Liu
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry
- Lanzhou University
- Lanzhou 730000
- China
- School of Pharmacy
| | - Xiaojun Yao
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry
- Lanzhou University
- Lanzhou 730000
- China
- State Key Laboratory of Quality Research in Chinese Medicine
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26
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He L, Wang X, Zhu D, Zhao C, Du W. Methionine oxidation of amyloid peptides by peroxovanadium complexes: inhibition of fibril formation through a distinct mechanism. Metallomics 2015; 7:1562-72. [DOI: 10.1039/c5mt00133a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Peroxovanadium complexes inhibit the fibril formation of neurodegenerative amyloid peptides by oxidizing methionine residues.
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Affiliation(s)
- Lei He
- Department of Chemistry
- Renmin University of China
- Beijing, China
| | - Xuesong Wang
- Department of Chemistry
- Renmin University of China
- Beijing, China
| | - Dengsen Zhu
- Department of Chemistry
- Renmin University of China
- Beijing, China
| | - Cong Zhao
- Department of Chemistry
- Renmin University of China
- Beijing, China
| | - Weihong Du
- Department of Chemistry
- Renmin University of China
- Beijing, China
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27
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Moon JH, Park SY. Baicalein prevents human prion protein-induced neuronal cell death by regulating JNK activation. Int J Mol Med 2014; 35:439-45. [PMID: 25435015 DOI: 10.3892/ijmm.2014.2010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 11/17/2014] [Indexed: 11/06/2022] Open
Abstract
Prion diseases are neurodegenerative disorders characterized by the accumulation of an abnormal isoform of the protease-insensitive isoform (PrPSc) of prion protein. Human prion protein fragment 106‑126 [PrP (106‑126)] contains most of the pathological characteristics associated with PrPSc. Although a number of compounds have been identified to inhibit PrP accumulation or dissolve fibrils and aggregates in vitro, there is currenlty no treatment available for these progressive neurodegenerative diseases. Baicalein, the dried root of Scutellaria baicalensis (S. baicalensis) Georgi (known as Huang-qin in traditional Chinese medicine) has been reported to exert neuroprotective effects on neurodegenerative diseases. In the present study, we investigated the effects of baicalein on the development of prion diseases using SH-SY5Y and SK-N-SH cells in vitro. We found that baicalein protected the cells against PrP‑induced neuronal cell death by inhibiting the production of reactive oxygen species (ROS) and mitochondrial dysfunction using ROS detection assay and MTP assay. We demonstrated that baicalein treatment regulated the phosphorylation of c-Jun N-terminal kinase (JNK) by using western blot analysis and Annexin V assay. Our data suggest that baicalein has potential for use as a therapeutic drug for the treatment of various neurodegenerative diseases, including prion diseases.
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Affiliation(s)
- Ji-Hong Moon
- Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
| | - Sang-Youel Park
- Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
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Kaur M, Healy J, Vasudevamurthy M, Lassé M, Puskar L, Tobin MJ, Valery C, Gerrard JA, Sasso L. Stability and cytotoxicity of crystallin amyloid nanofibrils. NANOSCALE 2014; 6:13169-78. [PMID: 25255060 DOI: 10.1039/c4nr04624b] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Previous work has identified crystallin proteins extracted from fish eye lenses as a cheap and readily available source for the self-assembly of amyloid nanofibrils. However, before exploring potential applications, the biophysical aspects and safety of this bionanomaterial need to be assessed so as to ensure that it can be effectively and safely used. In this study, crude crystallin amyloid fibrils are shown to be stable across a wide pH range, in a number of industrially relevant solvents, at both low and high temperatures, and in the presence of proteases. Crystallin nanofibrils were compared to well characterised insulin and whey protein fibrils using Thioflavin T assays and TEM imaging. Cell cytotoxicity assays suggest no adverse impact of both mature and fragmented crystallin fibrils on cell viability of Hec-1a endometrial cells. An IR microspectroscopy study supports long-term structural integrity of crystallin nanofibrils.
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Affiliation(s)
- Manmeet Kaur
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand.
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29
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Park YG, Park SY. Gingerol prevents prion protein-mediated neuronal toxicity by regulating HIF prolyl hydroxylase 2 and prion protein. Int J Mol Med 2014; 34:1268-76. [PMID: 25231392 PMCID: PMC4199419 DOI: 10.3892/ijmm.2014.1936] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 09/12/2014] [Indexed: 11/06/2022] Open
Abstract
Prion diseases are a family of progressive neurodegenerative disorders, which are fatal in the majority of cases and affect both humans and domestic animals. Prion protein (PrP) (106–126) retains the neurotoxic properties of the entire pathological PrPsc and it is generally used as a reasonable model to study the mechanisms responsible for prion diseases. In our previous studies, we demonstrated that hypoxia-inducible factor (HIF)-1α is involved in the gingerol-mediated protection of neuronal cells. HIF mediates cellular adaptations to low oxygen. Prolyl hydroxylase domain-containing protein 2 (PHD2) is an oxygen sensor that hydroxylates the HIF-α-subunit, promoting its proteasomal degradation under normoxic conditions. Thus, in the present study we wished to determine whether gingerol inhibits the catalytic activity of PHD2 and prevents HIF-1α protein proteasomal degradation, thereby preventing the occurrence of PrP (106–126)-induced neuronal apoptosis. We used the pharmacological inhibition of PHD2 by dimethyloxalylglycine (DMOG) or deferoxamine (DFO) and the genetic inhibition of HIF-1α by HIF-1α small interfering RNA (siRNA) to block the effects of gingerol against PrP (106–126)-induced neurotoxicity. Our results demonstrated that gingerol prevented PrP (106–126)-induced neuronal apoptosis by upregulating HIF-1α and inhibiting the catalytic activity of PHD2 under normoxic conditions. Moreover, the protective effects of gingerol against PrP (106–126)-induced neuronal apoptosis were associated with the upregulation of the expression of cellular prion protein (PrPc). In conclusion, our results indicate that gingerol has therapeutic potential for use in the treatment or prevention of prion diseases, and its inhibitory effects on the catalytic activity of PHD2 may be of clinical benefit.
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Affiliation(s)
- Yang-Gyu Park
- Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
| | - Sang-Youel Park
- Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
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Song ZQ, Yang LF, Wang YS, Zhu T, Zhou XM, Yin XM, Yao HQ, Zhao DM. Overexpression of BAT3 alleviates prion protein fragment PrP106-126-induced neuronal apoptosis. CNS Neurosci Ther 2014; 20:737-47. [PMID: 24629137 PMCID: PMC6493199 DOI: 10.1111/cns.12243] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 02/03/2014] [Accepted: 02/03/2014] [Indexed: 11/30/2022] Open
Abstract
BACKGROUNDS AND AIMS Prion diseases are a group of infectious neurodegenerative diseases characterized by neuronal death and degeneration. Human leukocyte antigen-B-associated transcript 3 (BAT3) is an important apoptosis regulator. We therefore investigated the interactions between BAT3 and prion protein and the potential role of BAT3 in PrP106-126-induced apoptosis. METHODS BAT3 and prion protein were overexpressed in Hela, Neuro2A, or primary neuronal cells by transfection with BAT3-HA or PRNP-EGFP expression plasmids and their relationship studied by immunofluorescence and Western blotting. The effect of BAT3 on PrP106-126-induced cytotoxicity and apoptosis was detected by the CCK-8 assay and terminal-deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay. The expression of cytochrome c and Bcl-2 was examined by Western blotting. RESULTS BAT3 interacted with prion protein and enhanced PrP expression. After PrP106-126 peptide treated, BAT3 was transported from the nucleus to cytoplasm, increased cell viability, and protected neurons from PrP106-126-induced apoptosis through stabilizing the level of Bcl-2 protein and inhibiting the release of cytochrome c to cytoplasm. CONCLUSIONS Our present data showed a novel molecular mechanism of PrP106-126-induced apoptotic process regulation through the overexpression of BAT3, which may be important for the basic regulatory mechanism of neuron survival in prion diseases and associated neurodegenerative diseases in vivo.
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Affiliation(s)
- Zhi-Qi Song
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
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31
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MOON JIHONG, LEE JUHEE, PARK JINYOUNG, KIM SUNGWOOK, LEE YOUJIN, KANG SEOGJIN, SEOL JAEWON, AHN DONGCHOON, PARK SANGYOUEL. Caffeine prevents human prion protein-mediated neurotoxicity through the induction of autophagy. Int J Mol Med 2014; 34:553-8. [DOI: 10.3892/ijmm.2014.1814] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 06/16/2014] [Indexed: 11/05/2022] Open
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Kojima A, Konishi M, Akizawa T. Prion fragment peptides are digested with membrane type matrix metalloproteinases and acquire enzyme resistance through Cu²⁺-binding. Biomolecules 2014; 4:510-26. [PMID: 24970228 PMCID: PMC4101495 DOI: 10.3390/biom4020510] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 04/02/2014] [Accepted: 04/11/2014] [Indexed: 11/16/2022] Open
Abstract
Prions are the cause of neurodegenerative disease in humans and other mammals. The structural conversion of the prion protein (PrP) from a normal cellular protein (PrPC) to a protease-resistant isoform (PrPSc) is thought to relate to Cu2+ binding to histidine residues. In this study, we focused on the membrane-type matrix metalloproteinases (MT-MMPs) such as MT1-MMP and MT3-MMP, which are expressed in the brain as PrPC-degrading proteases. We synthesized 21 prion fragment peptides. Each purified peptide was individually incubated with recombinant MT1-MMP or MT3-MMP in the presence or absence of Cu2+ and the cleavage sites determined by LC-ESI-MS analysis. Recombinant MMP-7 and human serum (HS) were also tested as control. hPrP61-90, from the octapeptide-repeat region, was cleaved by HS but not by the MMPs tested here. On the other hand, hPrP92-168 from the central region was cleaved by MT1-MMP and MT3-MMP at various sites. These cleavages were inhibited by treatment with Cu2+. The C-terminal peptides had higher resistance than the central region. The data obtained from this study suggest that MT-MMPs expressed in the brain might possess PrPC-degrading activity.
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Affiliation(s)
- Aya Kojima
- Analytical Chemistry, Pharmaceutical Science, Setsunan University, 45-1 Nagaotoge-cho, Hirakata, Osaka 573-0101, Japan.
| | - Motomi Konishi
- Analytical Chemistry, Pharmaceutical Science, Setsunan University, 45-1 Nagaotoge-cho, Hirakata, Osaka 573-0101, Japan.
| | - Toshifumi Akizawa
- Analytical Chemistry, Pharmaceutical Science, Setsunan University, 45-1 Nagaotoge-cho, Hirakata, Osaka 573-0101, Japan.
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33
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Wang X, Cui M, Zhao C, He L, Zhu D, Wang B, Du W. Regulation of aggregation behavior and neurotoxicity of prion neuropeptides by platinum complexes. Inorg Chem 2014; 53:5044-54. [PMID: 24787240 DOI: 10.1021/ic500092t] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Prion diseases belong to a group of infectious, fatal neurodegenerative disorders. The conformational conversion of a cellular prion protein (PrP(C)) into an abnormal misfolded isoform (PrP(Sc)) is the key event in prion disease pathology. PrP106-126 resembles PrP(Sc) in some physicochemical and biological characteristics, such as apoptosis induction in neurons, fibrillar formation, and mediation of the conversion of native cellular PrP(C) to PrP(Sc). Numerous studies have been conducted to explore the inhibiting methods on the aggregation and neurotoxicity of prion neuropeptide PrP106-126. We showed that PrP106-126 aggregation, as assessed by fluorescence assay and atomic force microscopy, is inhibited by platinum complexes cisplatin, carboplatin, and Pt(bpy)Cl2. ESI-MS and NMR assessments of PrP106-126 and its mutant peptides demonstrate that platinum complexes bind to the peptides in coordination and nonbonded interactions, which rely on the ligand properties and the peptide sequence. In peptides, methionine residue is preferred as a potent binding site over histidine residue for the studied platinum complexes, implying a typical thiophile characteristic of platinum. The neurotoxicity induced by PrP106-126 is better inhibited by Pt(bpy)Cl2 and cisplatin. Furthermore, the ligand configuration contributes to both the binding affinity and the inhibition of peptide aggregation. The pursuit of novel platinum candidates that selectively target prion neuropeptide is noteworthy for medicinal inorganic chemistry and chemical biology.
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Affiliation(s)
- Xuesong Wang
- Department of Chemistry, Renmin University of China , Beijing 100872, People's Republic of China
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34
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Copper-induced structural propensities of the amyloidogenic region of human prion protein. J Biol Inorg Chem 2014; 19:635-45. [DOI: 10.1007/s00775-014-1132-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Accepted: 04/02/2014] [Indexed: 12/15/2022]
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35
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Walsh P, Vanderlee G, Yau J, Campeau J, Sim VL, Yip CM, Sharpe S. The mechanism of membrane disruption by cytotoxic amyloid oligomers formed by prion protein(106-126) is dependent on bilayer composition. J Biol Chem 2014; 289:10419-10430. [PMID: 24554723 PMCID: PMC4036164 DOI: 10.1074/jbc.m113.515866] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 02/01/2014] [Indexed: 11/06/2022] Open
Abstract
The formation of fibrillar aggregates has long been associated with neurodegenerative disorders such as Alzheimer and Parkinson diseases. Although fibrils are still considered important to the pathology of these disorders, it is now widely understood that smaller amyloid oligomers are the toxic entities along the misfolding pathway. One characteristic shared by the majority of amyloid oligomers is the ability to disrupt membranes, a commonality proposed to be responsible for their toxicity, although the mechanisms linking this to cell death are poorly understood. Here, we describe the physical basis for the cytotoxicity of oligomers formed by the prion protein (PrP)-derived amyloid peptide PrP(106-126). We show that oligomers of this peptide kill several mammalian cells lines, as well as mouse cerebellar organotypic cultures, and we also show that they exhibit antimicrobial activity. Physical perturbation of model membranes mimicking bacterial or mammalian cells was investigated using atomic force microscopy, polarized total internal reflection fluorescence microscopy, and NMR spectroscopy. Disruption of anionic membranes proceeds through a carpet or detergent model as proposed for other antimicrobial peptides. By contrast, when added to zwitterionic membranes containing cholesterol-rich ordered domains, PrP(106-126) oligomers induce a loss of domain separation and decreased membrane disorder. Loss of raft-like domains may lead to activation of apoptotic pathways, resulting in cell death. This work sheds new light on the physical mechanisms of amyloid cytotoxicity and is the first to clearly show membrane type-specific modes of action for a cytotoxic peptide.
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Affiliation(s)
- Patrick Walsh
- Molecular Structure and Function Program, The Hospital for Sick Children, Toronto, Ontario M5G 1X8; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8
| | - Gillian Vanderlee
- Institute of Biomaterials and Biomedical Engineering, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1
| | - Jason Yau
- Molecular Structure and Function Program, The Hospital for Sick Children, Toronto, Ontario M5G 1X8; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8
| | - Jody Campeau
- Department of Medicine, Division of Neurology, University of Alberta, Edmonton, Alberta T6G 2G3, Canada
| | - Valerie L Sim
- Department of Medicine, Division of Neurology, University of Alberta, Edmonton, Alberta T6G 2G3, Canada
| | - Christopher M Yip
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8; Institute of Biomaterials and Biomedical Engineering, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1
| | - Simon Sharpe
- Molecular Structure and Function Program, The Hospital for Sick Children, Toronto, Ontario M5G 1X8; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8.
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36
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Ning L, Guo J, Bai Q, Jin N, Liu H, Yao X. Structural diversity and initial oligomerization of PrP106-126 studied by replica-exchange and conventional molecular dynamics simulations. PLoS One 2014; 9:e87266. [PMID: 24586266 PMCID: PMC3929351 DOI: 10.1371/journal.pone.0087266] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 12/24/2013] [Indexed: 12/15/2022] Open
Abstract
Prion diseases are marked by cerebral accumulation of the abnormal isoform of the prion protein. A fragment of prion protein composed of residues 106–126 (PrP106–126) exhibits similar properties to full length prion and plays a key role in the conformational conversion from cellular prion to its pathogenic pattern. Soluble oligomers of PrP106–126 have been proposed to be responsible for neurotoxicity. However, the monomeric conformational space and initial oligomerization of PrP106–126 are still obscure, which are very important for understanding the conformational conversion of PrP106–126. In this study, replica exchange molecular dynamics simulations were performed to investigate monomeric and dimeric states of PrP106–126 in implicit solvent. The structural diversity of PrP106–126 was observed and this peptide did not acquire stable structure. The dimeric PrP106–126 also displayed structural diversity and hydrophobic interaction drove the dimerization. To further study initial oligomerization of PrP106–126, 1 µs conventional molecular dynamics simulations of trimer and tetramer formation were carried out in implicit solvent. We have observed the spontaneous formation of several basic oligomers and stable oligomers with high β-sheet contents were sampled in the simulations of trimer and tetramer formation. The β-hairpin formed in hydrophobic tail of PrP106–126 with residues 118–120 in turn may stabilize these oligomers and seed the formation oligomers. This study can provide insight into the detailed information about the structure of PrP106–126 and the dynamics of aggregation of monomeric PrP106–126 into oligomers in atomic level.
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Affiliation(s)
- Lulu Ning
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, China
| | - Jingjing Guo
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, China
- School of Pharmacy, Lanzhou University, Lanzhou, China
| | - Qifeng Bai
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, China
| | | | - Huanxiang Liu
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, China
- School of Pharmacy, Lanzhou University, Lanzhou, China
- * E-mail: (HL); (XY)
| | - Xiaojun Yao
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, China
- State Key Lab for Quality Research in Chinese Medicines, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa, Macau, China
- * E-mail: (HL); (XY)
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37
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Cheng CJ, Daggett V. Molecular dynamics simulations capture the misfolding of the bovine prion protein at acidic pH. Biomolecules 2014; 4:181-201. [PMID: 24970211 PMCID: PMC4030982 DOI: 10.3390/biom4010181] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 02/07/2014] [Accepted: 02/09/2014] [Indexed: 12/24/2022] Open
Abstract
Bovine spongiform encephalopathy (BSE), or mad cow disease, is a fatal neurodegenerative disease that is transmissible to humans and that is currently incurable. BSE is caused by the prion protein (PrP), which adopts two conformers; PrPC is the native innocuous form, which is α-helix rich; and PrPSc is the β-sheet rich misfolded form, which is infectious and forms neurotoxic species. Acidic pH induces the conversion of PrPC to PrPSc. We have performed molecular dynamics simulations of bovine PrP at various pH regimes. An acidic pH environment induced conformational changes that were not observed in neutral pH simulations. Putative misfolded structures, with nonnative β-strands formed in the flexible N-terminal domain, were found in acidic pH simulations. Two distinct pathways were observed for the formation of nonnative β-strands: at low pH, hydrophobic contacts with M129 nucleated the nonnative β-strand; at mid-pH, polar contacts involving Q168 and D178 facilitated the formation of a hairpin at the flexible N-terminus. These mid- and low pH simulations capture the process of nonnative β-strand formation, thereby improving our understanding of how PrPC misfolds into the β-sheet rich PrPSc and how pH factors into the process.
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Affiliation(s)
- Chin Jung Cheng
- Department of Bioengineering, University of Washington, Seattle WA 98195-5013, USA.
| | - Valerie Daggett
- Department of Bioengineering, University of Washington, Seattle WA 98195-5013, USA.
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38
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c-Abl Tyrosine Kinase Mediates Neurotoxic Prion Peptide-Induced Neuronal Apoptosis via Regulating Mitochondrial Homeostasis. Mol Neurobiol 2014; 49:1102-16. [DOI: 10.1007/s12035-014-8646-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 01/14/2014] [Indexed: 12/19/2022]
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39
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Zhao C, Wang X, He L, Zhu D, Wang B, Du W. Influence of gold–bipyridyl derivants on aggregation and disaggregation of the prion neuropeptide PrP106–126. Metallomics 2014; 6:2117-25. [DOI: 10.1039/c4mt00219a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Gold–bipyridyl derivants affect aggregation and disaggregation of a prion neuropeptide PrP106–126.
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Affiliation(s)
- Cong Zhao
- Department of Chemistry
- Renmin University of China
- Beijing, China
| | - Xuesong Wang
- Department of Chemistry
- Renmin University of China
- Beijing, China
| | - Lei He
- Department of Chemistry
- Renmin University of China
- Beijing, China
| | - Dengsen Zhu
- Department of Chemistry
- Renmin University of China
- Beijing, China
| | - Baohuai Wang
- College of Chemistry and Molecular Engineering
- Peking University
- Beijing, China
| | - Weihong Du
- Department of Chemistry
- Renmin University of China
- Beijing, China
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40
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Inayathullah M, Satheeshkumar KS, Malkovskiy AV, Carre AL, Sivanesan S, Hardesty JO, Rajadas J. Solvent microenvironments and copper binding alters the conformation and toxicity of a prion fragment. PLoS One 2013; 8:e85160. [PMID: 24386462 PMCID: PMC3874036 DOI: 10.1371/journal.pone.0085160] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 11/22/2013] [Indexed: 11/19/2022] Open
Abstract
The secondary structures of amyloidogenic proteins are largely influenced by various intra and extra cellular microenvironments and metal ions that govern cytotoxicity. The secondary structure of a prion fragment, PrP(111-126), was determined using circular dichroism (CD) spectroscopy in various microenvironments. The conformational preferences of the prion peptide fragment were examined by changing solvent conditions and pH, and by introducing external stress (sonication). These physical and chemical environments simulate various cellular components at the water-membrane interface, namely differing aqueous environments and metal chelating ions. The results show that PrP(111-126) adopts different conformations in assembled and non-assembled forms. Aging studies on the PrP(111-126) peptide fragment in aqueous buffer demonstrated a structural transition from random coil to a stable β-sheet structure. A similar, but significantly accelerated structural transition was observed upon sonication in aqueous environment. With increasing TFE concentrations, the helical content of PrP(111-126) increased persistently during the structural transition process from random coil. In aqueous SDS solution, PrP(111-126) exhibited β-sheet conformation with greater α-helical content. No significant conformational changes were observed under various pH conditions. Addition of Cu2+ ions inhibited the structural transition and fibril formation of the peptide in a cell free in vitro system. The fact that Cu2+ supplementation attenuates the fibrillar assemblies and cytotoxicity of PrP(111-126) was witnessed through structural morphology studies using AFM as well as cytotoxicity using MTT measurements. We observed negligible effects during both physical and chemical stimulation on conformation of the prion fragment in the presence of Cu2+ ions. The toxicity of PrP(111-126) to cultured astrocytes was reduced following the addition of Cu2+ ions, owing to binding affinity of copper towards histidine moiety present in the peptide.
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Affiliation(s)
- Mohammed Inayathullah
- Biomaterials and Advanced Drug Delivery Laboratory, Stanford University School of Medicine, Stanford, California, United States of America
| | - K. S. Satheeshkumar
- Bioorganic and Neurochemistry Laboratory, Central Leather Research Institute, Adyar, Chennai, India
| | - Andrey V. Malkovskiy
- Biomaterials and Advanced Drug Delivery Laboratory, Stanford University School of Medicine, Stanford, California, United States of America
| | - Antoine L. Carre
- Department of Surgery, School of Medicine, Stanford University, Stanford, California, United States of America
| | - Senthilkumar Sivanesan
- Biomaterials and Advanced Drug Delivery Laboratory, Stanford University School of Medicine, Stanford, California, United States of America
| | - Jasper O. Hardesty
- Department of Chemical Engineering, Stanford University, Stanford, California, United States of America
| | - Jayakumar Rajadas
- Biomaterials and Advanced Drug Delivery Laboratory, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Neurology and Neurological Science, Stanford University School of Medicine, Stanford, California, United States of America
- Cardiovascular Pharmacology Division, Cardiovascular Institute, Stanford University School of Medicine, Stanford, California, United States of America
- *
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41
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Baral PK, Swayampakula M, Rout MK, Kav NNV, Spyracopoulos L, Aguzzi A, James MNG. Structural basis of prion inhibition by phenothiazine compounds. Structure 2013; 22:291-303. [PMID: 24373770 DOI: 10.1016/j.str.2013.11.009] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 11/19/2013] [Accepted: 11/20/2013] [Indexed: 01/10/2023]
Abstract
Conformational transitions of the cellular form of the prion protein, PrP(C), into an infectious isoform, PrP(Sc), are considered to be central events in the progression of fatal neurodegenerative diseases known as transmissible spongiform encephalopathies. Tricyclic phenothiazine compounds exhibit antiprion activity; however, the underlying molecular mechanism of PrP(Sc) inhibition remains elusive. We report the molecular structures of two phenothiazine compounds, promazine and chlorpromazine bound to a binding pocket formed at the intersection of the structured and the unstructured domains of the mouse prion protein. Promazine binding induces structural rearrangement of the unstructured region proximal to β1, through the formation of a "hydrophobic anchor." We demonstrate that these molecules, promazine in particular, allosterically stabilize the misfolding initiator-motifs such as the C terminus of α2, the α2-α3 loop, as well as the polymorphic β2-α2 loop. Hence, the stabilization effects of the phenothiazine derivatives on initiator-motifs induce a PrP(C) isoform that potentially resists oligomerization.
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Affiliation(s)
- Pravas Kumar Baral
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Mridula Swayampakula
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Manoj Kumar Rout
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Nat N V Kav
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada
| | - Leo Spyracopoulos
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Adriano Aguzzi
- Department of Pathology, Institute of Neuropathology, University Hospital Zurich, Zurich 8091, Switzerland
| | - Michael N G James
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.
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Shi F, Yang L, Wang J, Kouadir M, Yang Y, Fu Y, Zhou X, Yin X, Zhao D. Inhibition of phagocytosis reduced the classical activation of BV2 microglia induced by amyloidogenic fragments of beta-amyloid and prion proteins. Acta Biochim Biophys Sin (Shanghai) 2013; 45:973-8. [PMID: 24055815 DOI: 10.1093/abbs/gmt101] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The inflammatory responses in Alzheimer's disease and prion diseases are dominated by microglia activation. Three different phenotypes of microglial activation, namely classical activation, alternative activation, and acquired deactivation, have been described. In this study, we investigated the effect of amyloidogenic fragments of amyloid β and prion proteins (Aβ1-42 and PrP106-126) on various forms of microglial activation. We first examined the effect of Aβ1-42 and PrP106-126 stimulation on the mRNA expression levels of several markers of microglial activation, as well as the effect of cytochalasin D, a phagocytosis inhibitor, on microglial activation in Aβ1-42- and PrP106-126-stimulated BV2 microglia. results showed that Aβ1-42 and PrP106-126 induced the classical activation of BV2 microglia, decreased the expression level of alternative expression markers, and had no effect on the expression of acquired deactivation markers. Cytochalasin D treatment significantly reduced Aβ1-42- and PrP106-126-induced up-regulation of proinflammatory factors, but did not change the expression profile of the markers of alternative activation or acquired deactivation in BV2 cells which were exposed to Aβ1-42 and PrP106-126. Our results suggested that microglia interact with amyloidogenic peptides in the extracellular milieu-stimulated microglial classical activation and reduce its alternative activation, and that the uptake of amyloidogenic peptides from the extracellular milieu amplifies the classical microglial activation.
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Affiliation(s)
- Fushan Shi
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
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Wang X, Zhang B, Zhao C, Wang Y, He L, Cui M, Zhu X, Du W. Inhibition of human prion neuropeptide PrP106-126 aggregation by hexacoordinated ruthenium complexes. J Inorg Biochem 2013; 128:1-10. [DOI: 10.1016/j.jinorgbio.2013.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 07/05/2013] [Accepted: 07/08/2013] [Indexed: 11/24/2022]
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Wang X, He L, Zhao C, Du W, Lin J. Gold complexes inhibit the aggregation of prion neuropeptides. J Biol Inorg Chem 2013; 18:767-78. [DOI: 10.1007/s00775-013-1030-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 08/05/2013] [Indexed: 12/19/2022]
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Huang P, Lian F, Wen Y, Guo C, Lin D. Prion protein oligomer and its neurotoxicity. Acta Biochim Biophys Sin (Shanghai) 2013; 45:442-51. [PMID: 23557632 DOI: 10.1093/abbs/gmt037] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The prion diseases, also known as transmissible spongiform encephalopathies, are fatal neurodegenerative disorders. According to the 'protein only' hypothesis, the key molecular event in the pathogenesis of prion disease is the conformational conversion of the host-derived cellular prion protein (PrP(C)) into a misfolded form (scrapie PrP, PrP(Sc)). Increasing evidence has shown that the most infectious factor is the smaller subfibrillar oligomers formed by prion proteins. Both the prion oligomer and PrP(Sc) are rich in β-sheet structure and resistant to the proteolysis of proteinase K. The prion oligomer is soluble in physiologic environments whereas PrP(Sc) is insoluble. Various prion oligomers are formed in different conditions. Prion oligomers exhibited more neurotoxicity both in vitro and in vivo than the fibrillar forms of PrP(Sc), implying that prion oligomers could be potential drug targets for attacking prion diseases. In this article, we describe recent experimental evidence regarding prion oligomers, with a special focus on prion oligomer formation and its neurotoxicity.
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Affiliation(s)
- Pei Huang
- School of Life Science and Technology, China Pharmaceutical University, Nanjing 21009, China
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Shi F, Yang Y, Kouadir M, Fu Y, Yang L, Zhou X, Yin X, Zhao D. Inhibition of phagocytosis and lysosomal acidification suppresses neurotoxic prion peptide-induced NALP3 inflammasome activation in BV2 microglia. J Neuroimmunol 2013; 260:121-5. [PMID: 23680490 DOI: 10.1016/j.jneuroim.2013.04.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 04/11/2013] [Accepted: 04/15/2013] [Indexed: 11/17/2022]
Abstract
Prion diseases are neurodegenerative disorders characterized by the accumulation of misfolded prion protein. In a previous study, we showed that neurotoxic prion peptide (PrP106-126) induced NALP3 inflammasome activation in mouse primary and immortalized microglia. In the present work, we examined the relevance of phagocytosis and lysosomal acidification to the activation of the NALP3 inflammasome in PrP106-126-stimulated microglia. Our results showed that the inhibition of phagocytosis or lysosomal acidification significantly reduced IL-1β and IL-18 production, downregulated NALP3 and ASC expression, and decreased the expression of proinflammatory factors. We concluded that phagocytosis and lysosomal acidification are necessary for PrP106-126-induced NALP3 activation in BV2 cells.
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Affiliation(s)
- Fushan Shi
- Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
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Mahmood F, Hakimiyan A, Jayaraman V, Wood S, Sivaramakrishnan G, Rehman T, Reuhs BL, Chubinskaya S, Shafikhani SH. A novel human antimicrobial factor targets Pseudomonas aeruginosa through its type III secretion system. J Med Microbiol 2013; 62:531-539. [PMID: 23288430 DOI: 10.1099/jmm.0.051227-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Pseudomonas aeruginosa is an important opportunistic bacterial pathogen. Despite its metabolic and virulence versatility, it has not been shown to infect articular joints, which are areas that are rarely infected with bacteria in general. We hypothesized that articular joints possess antimicrobial activity that limits bacterial survival in these environments. We report that cartilages secrete a novel antimicrobial factor, henceforth referred to as the cartilage-associated antimicrobial factor (CA-AMF), with potent antimicrobial activity. Importantly, CA-AMF exhibited significantly more antimicrobial activity against P. aeruginosa strains with a functional type III secretion system (T3SS). We propose that CA-AMF represents a new class of human antimicrobial factors in innate immunity, one which has evolved to selectively target pathogenic bacteria among the beneficial and commensal microflora. The T3SS is the first example, to the best of our knowledge, of a pathogen-specific molecular target in this antimicrobial defence system.
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Affiliation(s)
- Fareeha Mahmood
- Department of Immunology/Microbiology, Rush University Medical Center, Chicago, IL 60612, USA
| | - Arnavaz Hakimiyan
- Department of Food Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Vijayakumar Jayaraman
- Department of Immunology/Microbiology, Rush University Medical Center, Chicago, IL 60612, USA
| | - Stephen Wood
- Department of Immunology/Microbiology, Rush University Medical Center, Chicago, IL 60612, USA
| | | | - Tooba Rehman
- Department of Immunology/Microbiology, Rush University Medical Center, Chicago, IL 60612, USA
| | - Bradley L Reuhs
- Department of Food Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Susanna Chubinskaya
- Department of Biochemistry, Rush University Medical Center, Chicago, IL 60612, USA
| | - Sasha H Shafikhani
- Department of Immunology/Microbiology, Rush University Medical Center, Chicago, IL 60612, USA
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Last V, Williams A, Werling D. Inhibition of cytosolic Phospholipase A2 prevents prion peptide-induced neuronal damage and co-localisation with Beta III Tubulin. BMC Neurosci 2012; 13:106. [PMID: 22928663 PMCID: PMC3496594 DOI: 10.1186/1471-2202-13-106] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 08/21/2012] [Indexed: 11/10/2022] Open
Abstract
Background Activation of phospholipase A2 (PLA2) and the subsequent metabolism of arachidonic acid (AA) to prostaglandins have been shown to play an important role in neuronal death in neurodegenerative disease. Here we report the effects of the prion peptide fragment HuPrP106-126 on the PLA2 cascade in primary cortical neurons and translocation of cPLA2 to neurites. Results Exposure of primary cortical neurons to HuPrP106-126 increased the levels of phosphorylated cPLA2 and caused phosphorylated cPLA2 to relocate from the cell body to the cellular neurite in a PrP-dependent manner, a previously unreported observation. HuPrP106-126 also induced significant AA release, an indicator of cPLA2 activation; this preceded synapse damage and subsequent cellular death. The novel translocation of p-cPLA2 postulated the potential for exposure to HuPrP106-126 to result in a re-arrangement of the cellular cytoskeleton. However p-cPLA2 did not colocalise significantly with F-actin, intermediate filaments, or microtubule-associated proteins. Conversely, p-cPLA2 did significantly colocalise with the cytoskeletal protein beta III tubulin. Pre-treatment with the PLA2 inhibitor, palmitoyl trifluoromethyl ketone (PACOCF3) reduced cPLA2 activation, AA release and damage to the neuronal synapse. Furthermore, PACOCF3 reduced expression of p-cPLA2 in neurites and inhibited colocalisation with beta III tubulin, resulting in protection against PrP-induced cell death. Conclusions Collectively, these findings suggest that cPLA2 plays a vital role in the action of HuPrP106-126 and that the colocalisation of p-cPLA2 with beta III tubulin could be central to the progress of neurodegeneration caused by prion peptides. Further work is needed to define exactly how PLA2 inhibitors protect neurons from peptide-induced toxicity and how this relates to intracellular structural changes occurring in neurodegeneration.
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Affiliation(s)
- Victoria Last
- Department of Pathology and Infectious Diseases, Royal Veterinary College, Hawkshead Lane, North Mymms, Hertfordshire AL9 7TA, UK.
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Shi F, Yang L, Kouadir M, Yang Y, Wang J, Zhou X, Yin X, Zhao D. The NALP3 inflammasome is involved in neurotoxic prion peptide-induced microglial activation. J Neuroinflammation 2012; 9:73. [PMID: 22531291 PMCID: PMC3394218 DOI: 10.1186/1742-2094-9-73] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2012] [Accepted: 04/24/2012] [Indexed: 12/13/2022] Open
Abstract
Background Prion diseases are neurodegenerative disorders characterized by the accumulation of an abnormal disease-associated prion protein, PrPSc. In prion-infected brains, activated microglia are often present in the vicinity of PrPSc aggregates, and microglial activation is thought to play a key role in the pathogenesis of prion diseases. Although interleukin (IL)-1β release by prion-induced microglia has been widely reported, the mechanism by which primed microglia become activated and secrete IL-1β in prion diseases has not yet been elucidated. In this study, we investigated the role of the NACHT, LRR and PYD domains-containing protein (NALP)3 inflammasome in IL-1β release from lipopolysaccharide (LPS)-primed microglia after exposure to a synthetic neurotoxic prion fragment (PrP106-126). Methods The inflammasome components NALP3 and apoptosis-associated speck-like protein (ASC) were knocked down by gene silencing. IL-1β production was assessed using ELISA. The mRNA expression of NALP3, ASC, and pro-inflammatory factors was measured by quantitative PCR. Western blot analysis was used to detect the protein level of NALP3, ASC, caspase-1 and nuclear factor-κB. Results We found that that PrP106-126-induced IL-1β release depends on NALP3 inflammasome activation, that inflammasome activation is required for the synthesis of pro-inflammatory and chemotactic factors by PrP106-126-activated microglia, that inhibition of NF-κB activation abrogated PrP106-126-induced NALP3 upregulation, and that potassium efflux and production of reactive oxygen species were implicated in PrP106-126-induced NALP3 inflammasome activation in microglia. Conclusions We conclude that the NALP3 inflammasome is involved in neurotoxic prion peptide-induced microglial activation. To our knowledge, this is the first time that strong evidence for the involvement of NALP3 inflammasome in prion-associated inflammation has been found.
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Affiliation(s)
- Fushan Shi
- State Key Laboratories for Agrobiotechnology, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
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Role of prion protein aggregation in neurotoxicity. Int J Mol Sci 2012; 13:8648-8669. [PMID: 22942726 PMCID: PMC3430257 DOI: 10.3390/ijms13078648] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 06/29/2012] [Accepted: 07/02/2012] [Indexed: 11/17/2022] Open
Abstract
In several neurodegenerative diseases, such as Parkinson, Alzheimer’s, Huntington, and prion diseases, the deposition of aggregated misfolded proteins is believed to be responsible for the neurotoxicity that characterizes these diseases. Prion protein (PrP), the protein responsible of prion diseases, has been deeply studied for the peculiar feature of its misfolded oligomers that are able to propagate within affected brains, inducing the conversion of the natively folded PrP into the pathological conformation. In this review, we summarize the available experimental evidence concerning the relationship between aggregation status of misfolded PrP and neuronal death in the course of prion diseases. In particular, we describe the main findings resulting from the use of different synthetic (mainly PrP106-126) and recombinant PrP-derived peptides, as far as mechanisms of aggregation and amyloid formation, and how these different spatial conformations can affect neuronal death. In particular, most data support the involvement of non-fibrillar oligomers rather than actual amyloid fibers as the determinant of neuronal death.
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