Cellular Prion Protein Mediates α‐Synuclein Uptake, Localization, and Toxicity In Vitro and In Vivo

Cellular prion protein (PrPC) is a glycosyl-phosphatidylinositol–anchored glycoprotein. When mutated or misfolded, the pathogenic form (PrPSC) induces transmissible spongiform encephalopathies. In contrast, PrPC has a number of physiological functions in several neural processes. Several lines of evidence implicate PrPC in synaptic transmission and neuroprotection since its absence results in an increase in neuronal excitability and enhanced excitotoxicity in vitro and in vivo. Furthermore, PrPC has been implicated in the inhibition of N-methyl-d-aspartic acid (NMDA)–mediated neurotransmission, and prion protein gene (Prnp) knockout mice show enhanced neuronal death in response to NMDA and kainate (KA). In this study, we demonstrate that neurotoxicity induced by KA in Prnp knockout mice depends on the c-Jun N-terminal kinase 3 (JNK3) pathway since Prnpo/oJnk3o/o mice were not affected by KA. Pharmacological blockage of JNK3 activity impaired PrPC-dependent neurotoxicity. Furthermore, our results indicate that JNK3 activation depends on the interaction of PrPC with postsynaptic density 95 protein (PSD-95) and glutamate receptor 6/7 (GluR6/7). Indeed, GluR6–PSD-95 interaction after KA injections was favored by the absence of PrPC. Finally, neurotoxicity in Prnp knockout mice was reversed by an AMPA/KA inhibitor (6,7-dinitroquinoxaline-2,3-dione) and the GluR6 antagonist NS-102. We conclude that the protection afforded by PrPC against KA is due to its ability to modulate GluR6/7-mediated neurotransmission and hence JNK3 activation.

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Expression and characterisation of fully posttranslationally modified cellular prion protein in Pichia pastoris

Biological Chemistry ◽

10.1515/hsz-2013-0180 ◽

2013 ◽

Vol 394 (11) ◽

pp. 1475-1483

Author(s):

Jendrik Marbach ◽

Peter Zentis ◽

Philipp Ellinger ◽

Henrik Müller ◽

Eva Birkmann

Keyword(s):

Plasma Membrane ◽

Pichia Pastoris ◽

Prion Protein ◽

Prion Diseases ◽

Phosphatidyl Inositol ◽

Cellular Prion Protein ◽

Glycosylation Pattern ◽

Signal Sequences

Abstract Prion diseases are fatal neurodegenerative diseases which occur as sporadic, genetic, and transmissible disorders. A molecular hallmark of prion diseases is the conformational conversion of the host-encoded cellular form of the prion protein (PrPC) into its misfolded pathogenic isoform (PrPSc). PrPSc is the main component of the pathological and infectious prion agent. The study of the conversion mechanism from PrPC to PrPSc is a major field in prion research. PrPC is glycosylated and attached to the plasma membrane via its glycosyl phosphatidyl inositol (GPI)-anchor. In this study we established and characterised the expression of fully posttranslationally modified mammalian Syrian golden hamster PrPC in the yeast Pichia pastoris using native PrPC-specific N- and C-terminal signal sequences. In vivo as well as in vitro-studies demonstrated that the signal sequences controlled posttranslational processing and trafficking of native PrPC, resulting in PrPC localised in the plasma membrane of P. pastoris. In addition, the glycosylation pattern of native PrPC could be confirmed.

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Prion protein attenuates excitotoxicity by inhibiting NMDA receptors

The Journal of Cell Biology ◽

10.1083/jcb.200711002 ◽

2008 ◽

Vol 181 (3) ◽

pp. 551-565 ◽

Cited By ~ 163

Author(s):

Houman Khosravani ◽

Yunfeng Zhang ◽

Shigeki Tsutsui ◽

Shahid Hameed ◽

Christophe Altier ◽

...

Keyword(s):

Nmda Receptors ◽

Prion Protein ◽

Hippocampal Neurons ◽

Neuronal Excitability ◽

Physiological Role ◽

Cellular Prion Protein ◽

Glutamate Excitotoxicity ◽

Null Mouse

It is well established that misfolded forms of cellular prion protein (PrP [PrPC]) are crucial in the genesis and progression of transmissible spongiform encephalitis, whereas the function of native PrPC remains incompletely understood. To determine the physiological role of PrPC, we examine the neurophysiological properties of hippocampal neurons isolated from PrP-null mice. We show that PrP-null mouse neurons exhibit enhanced and drastically prolonged N-methyl-d-aspartate (NMDA)–evoked currents as a result of a functional upregulation of NMDA receptors (NMDARs) containing NR2D subunits. These effects are phenocopied by RNA interference and are rescued upon the overexpression of exogenous PrPC. The enhanced NMDAR activity results in an increase in neuronal excitability as well as enhanced glutamate excitotoxicity both in vitro and in vivo. Thus, native PrPC mediates an important neuroprotective role by virtue of its ability to inhibit NR2D subunits.

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Mutated but Not Deleted Ovine PrPCN-Terminal Polybasic Region Strongly Interferes with Prion Propagation in Transgenic Mice

Journal of Virology ◽

10.1128/jvi.02805-15 ◽

2015 ◽

Vol 90 (3) ◽

pp. 1638-1646 ◽

Cited By ~ 4

Author(s):

Manal Khalifé ◽

Fabienne Reine ◽

Sophie Paquet-Fifield ◽

Johan Castille ◽

Laetitia Herzog ◽

...

Keyword(s):

Amino Acid ◽

Prion Protein ◽

Major Effect ◽

Cellular Prion Protein ◽

Spongiform Encephalopathy ◽

Structural Variations ◽

Prion Propagation ◽

Polybasic Region

ABSTRACTMammalian prions are proteinaceous infectious agents composed of misfolded assemblies of the host-encoded, cellular prion protein (PrP). Physiologically, the N-terminal polybasic region of residues 23 to 31 of PrP has been shown to be involved in its endocytic trafficking and interactions with glycosaminoglycans or putative ectodomains of membrane-associated proteins. Several recent reports also describe this PrP region as important for the toxicity of mutant prion proteins and the efficiency of prion propagation, bothin vitroandin vivo. The question remains as to whether the latter observations made with mouse PrP and mouse prions would be relevant to other PrP species/prion strain combinations given the dramatic impact on prion susceptibility of minimal amino acid substitutions and structural variations in PrP. Here, we report that transgenic mouse lines expressing ovine PrP with a deletion of residues 23 to 26 (KKRP) or mutated in this N-terminal region (KQHPH instead of KKRPK) exhibited a variable, strain-dependent susceptibility to prion infection with regard to the proportion of affected mice and disease tempo relative to findings in their wild-type counterparts. Deletion has no major effect on 127S scrapie prion pathogenesis, whereas mutation increased by almost 3-fold the survival time of the mice. Deletion marginally affected the incubation time of scrapie LA19K and ovine bovine spongiform encephalopathy (BSE) prions, whereas mutation caused apparent resistance to disease.IMPORTANCERecent reports suggested that the N-terminal polybasic region of the prion protein could be a therapeutic target to prevent prion propagation or toxic signaling associated with more common neurodegenerative diseases such as Alzheimer's disease. Mutating or deleting this region in ovine PrP completes the data previously obtained with the mouse protein by identifying the key amino acid residues involved.

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Cellular Prion Protein Promotes Brucella Infection into Macrophages

Journal of Experimental Medicine ◽

10.1084/jem.20021980 ◽

2003 ◽

Vol 198 (1) ◽

pp. 5-17 ◽

Cited By ~ 85

Author(s):

Masahisa Watarai ◽

Suk Kim ◽

Janchivdorj Erdenebaatar ◽

Sou-ichi Makino ◽

Motohiro Horiuchi ◽

...

Keyword(s):

Prion Protein ◽

Cellular Prion Protein ◽

Host Cells ◽

Human Brucellosis ◽

Intracellular Replication ◽

Bacterial Surface ◽

Brucella Infection ◽

Cellular Target

The products of the Brucella abortus virB gene locus, which are highly similar to conjugative DNA transfer system, enable the bacterium to replicate within macrophage vacuoles. The replicative phagosome is thought to be established by the interaction of a substrate of the VirB complex with macrophages, although the substrate and its host cellular target have not yet been identified. We report here that Hsp60, a member of the GroEL family of chaperonins, of B. abortus is capable of interacting directly or indirectly with cellular prion protein (PrPC) on host cells. Aggregation of PrPC tail-like formation was observed during bacterial swimming internalization into macrophages and PrPC was selectively incorporated into macropinosomes containing B. abortus. Hsp60 reacted strongly with serum from human brucellosis patients and was exposed on the bacterial surface via a VirB complex–associated process. Under in vitro and in vivo conditions, Hsp60 of B. abortus bound to PrPC. Hsp60 of B. abortus, expressed on the surface of Lactococcus lactis, promoted the aggregation of PrPC but not PrPC tail formation on macrophages. The PrPC deficiency prevented swimming internalization and intracellular replication of B. abortus, with the result that phagosomes bearing the bacteria were targeted into the endocytic network. These results indicate that signal transduction induced by the interaction between bacterial Hsp60 and PrPC on macrophages contributes to the establishment of B. abortus infection.

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C-Met-Activated Mesenchymal Stem Cells Rescue Ischemic Damage via Interaction with Cellular Prion Protein

Cellular Physiology and Biochemistry ◽

10.1159/000489368 ◽

2018 ◽

Vol 46 (5) ◽

pp. 1835-1848 ◽

Cited By ~ 3

Author(s):

Yong-Seok Han ◽

Seung Pil Yun ◽

Jun Hee Lee ◽

Seung-Hwan Kwon ◽

SangMin Kim ◽

...

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Prion Protein ◽

Caspase 3 ◽

Ischemic Injury ◽

Cellular Prion Protein ◽

Hypoxic Conditions ◽

Ischemic Tissue

Background/Aims: Stem cell transplantation has emerged as a promising therapeutic strategy, but the exact mechanisms by which stem cells exposed to hypoxic conditions increase the survival rate and rescue ischemic injury at the graft site are not well known. In this study, we aimed to determine if c-Met-activated mesenchymal stem cells (MSCs) pre-exposed to hypoxia promote therapeutic efficacy when transplanted to ischemic models, and whether c-Met interacts with cellular prion protein (PrPC) present in the ischemic tissue. Methods: Western blot analysis was performed to determine the expression levels of PrPC, C-caspase-3, and C-PARP-1, as well as the phosphorylation of Akt, p38, JNK, and BAX. A co-immunoprecipitation assay was performed to show that PrPC binds with c-Met in vitro. An adhesion assay was performed to explore the alterations in MSCs attached to myoblasts (in vitro), and an invasion assay was performed to determine the effect on MSC invasion capacity upon interaction with myoblast-induced c-Met and PrPC. CD31-positive capillaries and αSMA-positive arterioles in in vivo hindlimb ischemic tissue were quantified by immunofluorescence staining. The level of apoptosis in the tissue of each group was assessed by quantifying the number of C-caspase-3-positive cells. Finally, laser Doppler technology was utilized to detect the enhanced angiogenic effects in vivo. Results: We showed that hypoxic conditions increased PrPC levels in vivo (hindlimb ischemic tissue) and in vitro (myoblasts) and increased c-Met levels in MSCs. To identify the relationship between c-Met from MSCs and PrPC from myoblasts, we used a co-culturing system with myoblasts and MSCs pre-exposed to hypoxia. Hypoxia increased the phosphorylation of mitogen-activated protein kinases. Transplantation of hypoxia-pre-exposed MSCs to the ischemic site increased anti-apoptosis and enhanced the survival and proliferation of transplanted MSCs in a murine hindlimb model, resulting in improved functional recovery of the ischemic tissue. All the aforementioned effects were inhibited by the pretreatment of MSCs with the c-Met-neutralizing antibody Conclusion: c-Met-activated MSCs pre-exposed to hypoxia interact with PrPC at the site of ischemic injury to increase the efficiency of MSC transplantation. Hence, our study demonstrated that c-Met is a potential target for MSC-based therapies.

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Derivatives of Deoxypodophyllotoxin Induce Apoptosis Through Bcl-2/Bax Proteins Expression

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520620999200730160952 ◽

2020 ◽

Vol 20 ◽

Author(s):

Ya-Nan Li ◽

Ni Ning ◽

Lei Song ◽

Yun Geng ◽

Jun-Ting Fan ◽

...

Keyword(s):

Annexin V ◽

Mtt Method ◽

Anthriscus Sylvestris ◽

Anti Tumor Activity ◽

Derivatives Of ◽

Toxicity In Vitro ◽

Ht 29 ◽

Mcf 7

Background: Deoxypodophyllotoxin, isolated from theTraditional Chinese Medicine Anthriscus sylvestris, is well-known because of its significant antitumor activity with strong toxicity in vitro and in vivo. Objective: In this article, we synthesized a series of deoxypodophyllotoxin derivatives, and evaluated their antitumor effectiveness.Methods:The anti tumor activity of deoxypodophyllotoxin derivatives was investigated by the MTT method. Apoptosis percentage was measured by flow cytometer analysis using Annexin-V-FITC. Results: The derivatives revealed obvious cytotoxicity in the MTT assay by decreasing the number of late cancer cells. The decrease of Bcl-2/Bax could be observed in MCF-7, HepG2, HT-29 andMG-63 using Annexin V-FITC. The ratio of Bcl-2/Bax in the administration group was decreased, which was determined by the ELISA kit. Conclusion: The derivatives of deoxypodophyllotoxin could induce apoptosis in tumor cell lines by influencing Bcl-2/Bax.

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The Toxic Effects of Two Dental Materials on Human Buccal Epithelium In Vitro and Monkey Buccal Epithelium In Vivo

Alternatives to Laboratory Animals ◽

10.1177/026119298701400313 ◽

1987 ◽

Vol 14 (3) ◽

pp. 166-167

Author(s):

D. Arenholt-Bindslev ◽

P. Hørsted-Bindslev ◽

H.P. Philipsen

Keyword(s):

Dental Materials ◽

Microscopical Examination ◽

Buccal Epithelium ◽

Cytotoxic Effects ◽

Buccal Epithelial Cells ◽

Toxicity In Vitro ◽

Toxic Reactions ◽

Light Microscopical Examination

The aim of the present study was to compare the toxicity in vitro with the toxicity in vivo of two commercial chemicals marketed for use in the oral cavity (GLUMA BondR and 3M Etching LiquidR). Confluent cultures of human buccal epithelial cells were exposed to graded concentrations of GLUMA Bond or 3M Etching Liquid for 5 minutes. The cytotoxic effects induced by this treatment were observed (cytomorphology, proliferation rate). In vivo, monkey buccal epithelium was exposed to GLUMA Bond or 3M Etching Liquid for 5 minutes. Biopsies were taken after 24 hours, and the buccal epithelium processed for light microscopical examination. In both models, the toxic reactions to GLUMA Bond were far more extensive than those caused by 3M Etching Liquid.

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Prion Diseases: A Unique Transmissible Agent or a Model for Neurodegenerative Diseases?

Biomolecules ◽

10.3390/biom11020207 ◽

2021 ◽

Vol 11 (2) ◽

pp. 207

Author(s):

Diane L. Ritchie ◽

Marcelo A. Barria

Keyword(s):

Public Health ◽

Neurodegenerative Diseases ◽

Prion Protein ◽

Neurodegenerative Disorders ◽

Prion Diseases ◽

Experimental Models ◽

Misfolded Proteins ◽

Current Evidence

The accumulation and propagation in the brain of misfolded proteins is a pathological hallmark shared by many neurodegenerative diseases such as Alzheimer’s disease (Aβ and tau), Parkinson’s disease (α-synuclein), and prion disease (prion protein). Currently, there is no epidemiological evidence to suggest that neurodegenerative disorders are infectious, apart from prion diseases. However, there is an increasing body of evidence from experimental models to suggest that other pathogenic proteins such as Aβ and tau can propagate in vivo and in vitro in a prion-like mechanism, inducing the formation of misfolded protein aggregates such as amyloid plaques and neurofibrillary tangles. Such similarities have raised concerns that misfolded proteins, other than the prion protein, could potentially transmit from person-to-person as rare events after lengthy incubation periods. Such concerns have been heightened following a number of recent reports of the possible inadvertent transmission of Aβ pathology via medical and surgical procedures. This review will provide a historical perspective on the unique transmissible nature of prion diseases, examining their impact on public health and the ongoing concerns raised by this rare group of disorders. Additionally, this review will provide an insight into current evidence supporting the potential transmissibility of other pathogenic proteins associated with more common neurodegenerative disorders and the potential implications for public health.

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Antimicrobial and antibiofilm activities of meropenem loaded-mesoporous silica nanoparticles against carbapenem-resistant Pseudomonas aeruginosa

Journal of Biomaterials Applications ◽

10.1177/08853282211003848 ◽

2021 ◽

pp. 088532822110038

Author(s):

Mohammad Yousef Memar ◽

Mina Yekani ◽

Hadi Ghanbari ◽

Edris Nabizadeh ◽

Sepideh Zununi Vahed ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Mesoporous Silica ◽

Silica Nanoparticles ◽

Mesoporous Silica Nanoparticles ◽

Carbapenem Resistant ◽

Toxicity In Vitro ◽

Different Levels

The aims of the present study were the determination of antimicrobial and antibiofilm effects of meropenem-loaded mesoporous silica nanoparticles (MSNs) on carbapenem resistant Pseudomonas aeruginosa ( P. aeruginosa) and cytotoxicity properties in vitro. The meropenem-loaded MSNs had shown antibacterial and biofilm inhibitory activities on all isolates at different levels lower than MICs and BICs of meropenem. The viability of HC-04 cells treated with serial concentrations as MICs and BICs of meropenem-loaded MSNs was 92–100%. According to the obtained results, meropenem-loaded MSNs display the significant antibacterial and antibiofilm effects against carbapenem resistant and biofilm forming P. aeruginosa and low cell toxicity in vitro. Then, the prepared system can be an appropriate option for the delivery of carbapenem for further evaluation in vivo assays.

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