scholarly journals Direct interaction of HIV gp120 with neuronal CXCR4 and CCR5 receptors induces cofilin-actin rod pathology via a cellular prion protein- and NOX-dependent mechanism

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248309
Author(s):  
Lisa K. Smith ◽  
Isaac W. Babcock ◽  
Laurie S. Minamide ◽  
Alisa E. Shaw ◽  
James R. Bamburg ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Prion Protein ◽  
Hippocampal Neurons ◽  
Molecular Mechanisms ◽  
Amyloid Β ◽  
Direct Interaction ◽  
Cellular Prion Protein ◽  
Synaptic Function ◽  
Viral Envelope ◽  
Glycoprotein Gp120

Nearly 50% of individuals with long-term HIV infection are affected by the onset of progressive HIV-associated neurocognitive disorders (HAND). HIV infiltrates the central nervous system (CNS) early during primary infection where it establishes persistent infection in microglia (resident macrophages) and astrocytes that in turn release inflammatory cytokines, small neurotoxic mediators, and viral proteins. While the molecular mechanisms underlying pathology in HAND remain poorly understood, synaptodendritic damage has emerged as a hallmark of HIV infection of the CNS. Here, we report that the HIV viral envelope glycoprotein gp120 induces the formation of aberrant, rod-shaped cofilin-actin inclusions (rods) in cultured mouse hippocampal neurons via a signaling pathway common to other neurodegenerative stimuli including oligomeric, soluble amyloid-β and proinflammatory cytokines. Previous studies showed that synaptic function is impaired preferentially in the distal proximity of rods within dendrites. Our studies demonstrate gp120 binding to either chemokine co-receptor CCR5 or CXCR4 is capable of inducing rod formation, and signaling through this pathway requires active NADPH oxidase presumably through the formation of superoxide (O2-) and the expression of cellular prion protein (PrPC). These findings link gp120-mediated oxidative stress to the generation of rods, which may underlie early synaptic dysfunction observed in HAND.

scholarly journals Prion protein and prion disease at a glance

2021 ◽  
Vol 134 (17) ◽  
Author(s):  
Caihong Zhu ◽  
Adriano Aguzzi
Keyword(s):  
Prion Protein ◽  
Prion Disease ◽  
Neurodegenerative Disorders ◽  
Prion Diseases ◽  
Amyloid Β ◽  
Cellular Prion Protein ◽  
Future Studies ◽  
Associated Proteins ◽  
Main Component ◽  
Conformational Conversion

ABSTRACT Prion diseases are neurodegenerative disorders caused by conformational conversion of the cellular prion protein (PrPC) into scrapie prion protein (PrPSc). As the main component of prion, PrPSc acts as an infectious template that recruits and converts normal cellular PrPC into its pathogenic, misfolded isoform. Intriguingly, the phenomenon of prionoid, or prion-like, spread has also been observed in many other disease-associated proteins, such as amyloid β (Aβ), tau and α-synuclein. This Cell Science at a Glance and the accompanying poster highlight recently described physiological roles of prion protein and the advanced understanding of pathogenesis of prion disease they have afforded. Importantly, prion protein may also be involved in the pathogenesis of other neurodegenerative disorders such as Alzheimer's and Parkinson's disease. Therapeutic studies of prion disease have also exploited novel strategies to combat these devastating diseases. Future studies on prion protein and prion disease will deepen our understanding of the pathogenesis of a broad spectrum of neurodegenerative conditions.

scholarly journals Dimerization of the cellular prion protein inhibits propagation of scrapie prions

2018 ◽  
Vol 293 (21) ◽  
pp. 8020-8031 ◽  
Author(s):  
Anna D. Engelke ◽  
Anika Gonsberg ◽  
Simrika Thapa ◽  
Sebastian Jung ◽  
Sarah Ulbrich ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Prion Protein ◽  
Conformational Transition ◽  
Prion Diseases ◽  
Neuroblastoma Cells ◽  
Direct Interaction ◽  
Cellular Prion Protein ◽  
Dominant Negative ◽  
Dimerization Domain ◽  
Hydrophobic Domain

A central step in the pathogenesis of prion diseases is the conformational transition of the cellular prion protein (PrPC) into the scrapie isoform, denoted PrPSc. Studies in transgenic mice have indicated that this conversion requires a direct interaction between PrPC and PrPSc; however, insights into the underlying mechanisms are still missing. Interestingly, only a subfraction of PrPC is converted in scrapie-infected cells, suggesting that not all PrPC species are suitable substrates for the conversion. On the basis of the observation that PrPC can form homodimers under physiological conditions with the internal hydrophobic domain (HD) serving as a putative dimerization domain, we wondered whether PrP dimerization is involved in the formation of neurotoxic and/or infectious PrP conformers. Here, we analyzed the possible impact on dimerization of pathogenic mutations in the HD that induce a spontaneous neurodegenerative disease in transgenic mice. Similarly to wildtype (WT) PrPC, the neurotoxic variant PrP(AV3) formed homodimers as well as heterodimers with WTPrPC. Notably, forced PrP dimerization via an intermolecular disulfide bond did not interfere with its maturation and intracellular trafficking. Covalently linked PrP dimers were complex glycosylated, GPI-anchored, and sorted to the outer leaflet of the plasma membrane. However, forced PrPC dimerization completely blocked its conversion into PrPSc in chronically scrapie-infected mouse neuroblastoma cells. Moreover, PrPC dimers had a dominant-negative inhibition effect on the conversion of monomeric PrPC. Our findings suggest that PrPC monomers are the major substrates for PrPSc propagation and that it may be possible to halt prion formation by stabilizing PrPC dimers.

scholarly journals Impact of the Cellular Prion Protein on Amyloid-β and 3PO-Tau Processing

2013 ◽  
Vol 38 (3) ◽  
pp. 551-565 ◽  
Author(s):  
Matthias Schmitz ◽  
Katharina Wulf ◽  
Sandra C. Signore ◽  
Walter J. Schulz-Schaeffer ◽  
Pawel Kermer ◽  
...  
Keyword(s):  
Prion Protein ◽  
Amyloid Β ◽  
Cellular Prion Protein

scholarly journals A Promising Antiprion Trimethoxychalcone Binds to the Globular Domain of the Cellular Prion Protein and Changes Its Cellular Location

2017 ◽  
Vol 62 (2) ◽  
Author(s):  
N. C. Ferreira ◽  
L. M. Ascari ◽  
A. G. Hughson ◽  
G. R. Cavalheiro ◽  
C. F. Góes ◽  
...  
Keyword(s):  
Cell Surface ◽  
Real Time ◽  
Prion Protein ◽  
Molecular Mechanisms ◽  
Cellular Prion Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Globular Domain ◽  
Mrna Levels ◽  
Spongiform Encephalopathies

ABSTRACTThe search for antiprion compounds has been encouraged by the fact that transmissible spongiform encephalopathies (TSEs) share molecular mechanisms with more prevalent neurodegenerative pathologies, such as Parkinson's and Alzheimer's diseases. Cellular prion protein (PrPC) conversion into protease-resistant forms (protease-resistant PrP [PrPRes] or the scrapie form of PrP [PrPSc]) is a critical step in the development of TSEs and is thus one of the main targets in the screening for antiprion compounds. In this work, three trimethoxychalcones (compounds J1, J8, and J20) and one oxadiazole (compound Y17), previously identifiedin vitroto be potential antiprion compounds, were evaluated through different approaches in order to gain inferences about their mechanisms of action. None of them changed PrPCmRNA levels in N2a cells, as shown by reverse transcription-quantitative real-time PCR. Among them, J8 and Y17 were effective in real-time quaking-induced conversion reactions using rodent recombinant PrP (rPrP) from residues 23 to 231 (rPrP23–231) as the substrate and PrPScseeds from hamster and human brain. However, when rPrP from residues 90 to 231 (rPrP90–231), which lacks the N-terminal domain, was used as the substrate, only J8 remained effective, indicating that this region is important for Y17 activity, while J8 seems to interact with the PrPCglobular domain. J8 also reduced the fibrillation of mouse rPrP23–231seeded within vitro-produced fibrils. Furthermore, most of the compounds decreased the amount of PrPCon the N2a cell surface by trapping this protein in the endoplasmic reticulum. On the basis of these results, we hypothesize that J8, a nontoxic compound previously shown to be a promising antiprion agent, may act by different mechanisms, since its efficacy is attributable not only to PrP conversion inhibition but also to a reduction of the PrPCcontent on the cell surface.

scholarly journals Cofilin and Actin Dynamics: Multiple Modes of Regulation and Their Impacts in Neuronal Development and Degeneration

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2726
Author(s):  
James R. Bamburg ◽  
Laurie S. Minamide ◽  
O’Neil Wiggan ◽  
Lubna H. Tahtamouni ◽  
Thomas B. Kuhn
Keyword(s):  
Cortical Neurons ◽  
Hippocampal Neurons ◽  
Translational Regulation ◽  
Neuronal Development ◽  
Mitochondrial Fission ◽  
Amyloid Β ◽  
Cellular Prion Protein ◽  
Actin Dynamics ◽  
Specific Regulation ◽  
And Function

Proteins of the actin depolymerizing factor (ADF)/cofilin family are ubiquitous among eukaryotes and are essential regulators of actin dynamics and function. Mammalian neurons express cofilin-1 as the major isoform, but ADF and cofilin-2 are also expressed. All isoforms bind preferentially and cooperatively along ADP-subunits in F-actin, affecting the filament helical rotation, and when either alone or when enhanced by other proteins, promotes filament severing and subunit turnover. Although self-regulating cofilin-mediated actin dynamics can drive motility without post-translational regulation, cells utilize many mechanisms to locally control cofilin, including cooperation/competition with other proteins. Newly identified post-translational modifications function with or are independent from the well-established phosphorylation of serine 3 and provide unexplored avenues for isoform specific regulation. Cofilin modulates actin transport and function in the nucleus as well as actin organization associated with mitochondrial fission and mitophagy. Under neuronal stress conditions, cofilin-saturated F-actin fragments can undergo oxidative cross-linking and bundle together to form cofilin-actin rods. Rods form in abundance within neurons around brain ischemic lesions and can be rapidly induced in neurites of most hippocampal and cortical neurons through energy depletion or glutamate-induced excitotoxicity. In ~20% of rodent hippocampal neurons, rods form more slowly in a receptor-mediated process triggered by factors intimately connected to disease-related dementias, e.g., amyloid-β in Alzheimer’s disease. This rod-inducing pathway requires a cellular prion protein, NADPH oxidase, and G-protein coupled receptors, e.g., CXCR4 and CCR5. Here, we will review many aspects of cofilin regulation and its contribution to synaptic loss and pathology of neurodegenerative diseases.

scholarly journals Targeting glutamatergic and cellular prion protein mechanisms of amyloid β-mediated persistent synaptic plasticity disruption: Longitudinal studies

2017 ◽  
Vol 121 ◽  
pp. 231-246 ◽  
Author(s):  
Dainan Zhang ◽  
Yingjie Qi ◽  
Igor Klyubin ◽  
Tomas Ondrejcak ◽  
Claire J. Sarell ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Longitudinal Studies ◽  
Prion Protein ◽  
Amyloid Β ◽  
Cellular Prion Protein

scholarly journals Dextran sulfate sodium inhibits amyloid-β oligomer binding to cellular prion protein

2015 ◽  
Vol 134 (4) ◽  
pp. 611-617 ◽  
Author(s):  
Takahiro Aimi ◽  
Koichiro Suzuki ◽  
Tatsuya Hoshino ◽  
Tohru Mizushima
Keyword(s):  
Prion Protein ◽  
Dextran Sulfate ◽  
Dextran Sulfate Sodium ◽  
Amyloid Β ◽  
Cellular Prion Protein

scholarly journals Cellular prion protein mediates impairment of synaptic plasticity by amyloid-β oligomers

Nature ◽  
2009 ◽  
Vol 457 (7233) ◽  
pp. 1128-1132 ◽  
Author(s):  
Juha Laurén ◽  
David A. Gimbel ◽  
Haakon B. Nygaard ◽  
John W. Gilbert ◽  
Stephen M. Strittmatter
Keyword(s):  
Synaptic Plasticity ◽  
Prion Protein ◽  
Amyloid Β ◽  
Cellular Prion Protein

scholarly journals Berberine Alleviates Amyloid β-Induced Mitochondrial Dysfunction and Synaptic Loss

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Chunhui Zhao ◽  
Ping Su ◽  
Cui Lv ◽  
Limin Guo ◽  
Guoqiong Cao ◽  
...  
Keyword(s):  
Hippocampal Neurons ◽  
Amyloid Β ◽  
Isoquinoline Alkaloid ◽  
Synaptic Function ◽  
Protective Mechanism ◽  
Pathological Feature ◽  
Synaptic Loss ◽  
Beneficial Effects ◽  
Mitochondrial Motility ◽  
Cultured Hippocampal Neurons

Synaptic structural and functional damage is a typical pathological feature of Alzheimer’s disease (AD). Normal axonal mitochondrial function and transportation are vital to synaptic function and plasticity because they are necessary for maintaining cellular energy supply and regulating calcium and redox signalling as well as synaptic transmission and vesicle release. Amyloid-β (Aβ) accumulation is another pathological hallmark of AD that mediates synaptic loss and dysfunction by targeting mitochondria. Therefore, it is important to develop strategies to protect against synaptic mitochondrial damage induced by Aβ. The present study examined the beneficial effects of berberine, a natural isoquinoline alkaloid extracted from the traditional medicinal plant Coptis chinensis, on Aβ-induced mitochondrial and synaptic damage in primary cultured hippocampal neurons. We demonstrate that berberine alleviates axonal mitochondrial abnormalities by preserving the mitochondrial membrane potential and preventing decreases in ATP, increasing axonal mitochondrial density and length, and improving mitochondrial motility and trafficking in cultured hippocampal neurons. Although the underlying protective mechanism remains to be elucidated, the data suggest that the effects of berberine were in part related to its potent antioxidant activity. These findings highlight the neuroprotective and specifically mitoprotective effects of berberine treatment under conditions of Aβ enrichment.

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