Impact of α-synuclein fibrillar strains and β-amyloid assemblies on mouse cortical neurons endo-lysosomal logistics

Endosomal transport and positioning cooperate in the establishment of neuronal compartment architecture, dynamics and function, contributing to neuronal intracellular logistics. Furthermore, endo-lysosomal dysfunction has been identified as a common mechanism in neurodegenerative diseases. Here, we analyzed endo-lysosomal transport when α-synuclein (α-syn) fibrillar polymorphs, β-amyloid (Aβ) fibrils and oligomers were externally applied on primary cultures of mouse cortical neurons. To measure this transport, we used a simple readout based on the spontaneous endocytosis in cultured neurons of fluorescent nanodiamonds, a perfectly stable nano-emitter, and the subsequent automatic extraction and quantification of their directed motions at high-throughput. α-syn fibrillar polymorphs, Aβ fibrils and oligomers induce a two-fold decrease of the fraction of nanodiamonds transported along microtubules, while only slightly reducing their interaction with cortical neurons. This important decrease in moving endosomes is expected to have a huge impact on neuronal homeostasis. We next assessed lysosomes dynamics, using Lysotracker. Neurons exposure to Aβ oligomers led to an increase in the number of lysosomes, a decrease in the fraction of moving lysosome and an increase in their size, reminiscent of that found in APP transgenic model of Alzheimer disease. We then analyzed the effect of α-syn fibrillar polymorphs, Aβ fibrils and oligomers on endosomal and lysosomal transport and quantified directed transport of those assemblies within cortical neurons. We report different impacts on endosomal and lysosomal transport parameters and differences in the trajectory lengths of cargoes loaded with pathogenic protein assemblies. Our results suggest that intraneuronal pathogenic protein aggregates internalization and transport may represent a target for novel neuroprotective therapeutic strategies.

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Neurotrophic Effect of Fish-Lecithin Based Nanoliposomes on Cortical Neurons

Marine Drugs ◽

10.3390/md17070406 ◽

2019 ◽

Vol 17 (7) ◽

pp. 406 ◽

Cited By ~ 4

Author(s):

Catherine Malaplate ◽

Aurelia Poerio ◽

Marion Huguet ◽

Claire Soligot ◽

Elodie Passeri ◽

...

Keyword(s):

Fatty Acid ◽

Cortical Neurons ◽

Neuronal Development ◽

Synapse Formation ◽

Fatty Acid Content ◽

Primary Cultures ◽

Synaptic Membrane ◽

Neuronal Membranes ◽

Acid Ratio ◽

And Function

Lipids play multiple roles in preserving neuronal function and synaptic plasticity, and polyunsaturated fatty acids (PUFAs) have been of particular interest in optimizing synaptic membrane organization and function. We developed a green-based methodology to prepare nanoliposomes (NL) from lecithin that was extracted from fish head by-products. These NL range between 100–120 nm in diameter, with an n-3/n-6 fatty acid ratio of 8.88. The high content of n-3 PUFA (46.3% of total fatty acid content) and docosahexanoic acid (26%) in these NL represented a means for enrichment of neuronal membranes that are potentially beneficial for neuronal growth and synaptogenesis. To test this, the primary cultures of rat embryo cortical neurons were incubated with NL on day 3 post-culture for 24 h, followed by immunoblots or immunofluorescence to evaluate the NL effects on synaptogenesis, axonal growth, and dendrite formation. The results revealed that NL-treated cells displayed a level of neurite outgrowth and arborization on day 4 that was similar to those of untreated cells on day 5 and 6, suggesting accelerated synapse formation and neuronal development in the presence of NL. We propose that fish-derived NL, by virtue of their n-3 PUFA profile and neurotrophic effects, represent a new innovative bioactive vector for developing preventive or curative treatments for neurodegenerative diseases.

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JNK3 as Therapeutic Target and Biomarker in Neurodegenerative and Neurodevelopmental Brain Diseases

Cells ◽

10.3390/cells9102190 ◽

2020 ◽

Vol 9 (10) ◽

pp. 2190

Author(s):

Clara Alice Musi ◽

Graziella Agrò ◽

Francesco Santarella ◽

Erika Iervasi ◽

Tiziana Borsello

Keyword(s):

Brain Diseases ◽

Synaptic Dysfunction ◽

Common Mechanism ◽

Cellular Functions ◽

Prodromal Phase ◽

Aβ Oligomers ◽

Disease Biomarker ◽

The Central Nervous System ◽

And Function ◽

The Brain

The c-Jun N-terminal kinase 3 (JNK3) is the JNK isoform mainly expressed in the brain. It is the most responsive to many stress stimuli in the central nervous system from ischemia to Aβ oligomers toxicity. JNK3 activity is spatial and temporal organized by its scaffold protein, in particular JIP-1 and β-arrestin-2, which play a crucial role in regulating different cellular functions in different cellular districts. Extensive evidence has highlighted the possibility of exploiting these adaptors to interfere with JNK3 signaling in order to block its action. JNK plays a key role in the first neurodegenerative event, the perturbation of physiological synapse structure and function, known as synaptic dysfunction. Importantly, this is a common mechanism in many different brain pathologies. Synaptic dysfunction and spine loss have been reported to be pharmacologically reversible, opening new therapeutic directions in brain diseases. Being JNK3-detectable at the peripheral level, it could be used as a disease biomarker with the ultimate aim of allowing an early diagnosis of neurodegenerative and neurodevelopment diseases in a still prodromal phase.

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The Protective Effects of Jatrorrhizine on β-Amyloid (25-35)-Induced Neurotoxicity in Rat Cortical Neurons

CNS & Neurological Disorders - Drug Targets ◽

10.2174/1871527311211080013 ◽

2013 ◽

Vol 11 (8) ◽

pp. 1030-1037 ◽

Cited By ~ 17

Author(s):

Tao Luo ◽

Wei Jiang ◽

Yan Kong ◽

Sheng Li ◽

Feng He ◽

...

Keyword(s):

Cortical Neurons ◽

Protective Effects ◽

Rat Cortical Neurons ◽

Β Amyloid

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Anti-Parallel β-Hairpin Structure in Soluble Aβ Oligomers of Aβ40-Dutch and Aβ40-Iowa

International Journal of Molecular Sciences ◽

10.3390/ijms22031225 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1225

Author(s):

Ziao Fu ◽

William E. Van Nostrand ◽

Steven O. Smith

Keyword(s):

Amyloid Β ◽

Amyloid Angiopathy ◽

Aβ Oligomers ◽

Dominant Component ◽

Fibril Structure ◽

Predominant Component ◽

Aβ Aggregation ◽

Aβ Fibrils ◽

Soluble Aβ Oligomers ◽

Β Sheet

The amyloid-β (Aβ) peptides are associated with two prominent diseases in the brain, Alzheimer’s disease (AD) and cerebral amyloid angiopathy (CAA). Aβ42 is the dominant component of cored parenchymal plaques associated with AD, while Aβ40 is the predominant component of vascular amyloid associated with CAA. There are familial CAA mutations at positions Glu22 and Asp23 that lead to aggressive Aβ aggregation, drive vascular amyloid deposition and result in degradation of vascular membranes. In this study, we compared the transition of the monomeric Aβ40-WT peptide into soluble oligomers and fibrils with the corresponding transitions of the Aβ40-Dutch (E22Q), Aβ40-Iowa (D23N) and Aβ40-Dutch, Iowa (E22Q, D23N) mutants. FTIR measurements show that in a fashion similar to Aβ40-WT, the familial CAA mutants form transient intermediates with anti-parallel β-structure. This structure appears before the formation of cross-β-sheet fibrils as determined by thioflavin T fluorescence and circular dichroism spectroscopy and occurs when AFM images reveal the presence of soluble oligomers and protofibrils. Although the anti-parallel β-hairpin is a common intermediate on the pathway to Aβ fibrils for the four peptides studied, the rate of conversion to cross-β-sheet fibril structure differs for each.

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The Bacterial Enzyme Cas13 Interferes with Neurite Outgrowth from Cultured Cortical Neurons

Toxins ◽

10.3390/toxins13040262 ◽

2021 ◽

Vol 13 (4) ◽

pp. 262

Author(s):

Qin-Wei Wu ◽

Josef P. Kapfhammer

Keyword(s):

Rna Editing ◽

Cortical Neurons ◽

High Efficiency ◽

Primary Cultures ◽

Cultured Neurons ◽

Therapeutic Tool ◽

Bacterial Enzyme ◽

Rna Targeting ◽

Cultured Cortical Neurons ◽

New Generation

The CRISPR-Cas13 system based on a bacterial enzyme has been explored as a powerful new method for RNA manipulation. Due to the high efficiency and specificity of RNA editing/interference achieved by this system, it is currently being developed as a new therapeutic tool for the treatment of neurological and other diseases. However, the safety of this new generation of RNA therapies is still unclear. In this study, we constructed a vector expressing CRISPR-Cas13 under a constitutive neuron-specific promoter. CRISPR-Cas13 from Leptotrichia wadei was expressed in primary cultures of mouse cortical neurons. We found that the presence of CRISPR-Cas13 impedes the development of cultured neurons. These results show a neurotoxic action of Cas13 and call for more studies to test for and possibly mitigate the toxic effects of Cas13 enzymes in order to improve CRISPR-Cas13-based tools for RNA targeting.

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Interleukin-4 Regulates the Expression of CD209 and Subsequent Uptake of Mycobacterium leprae by Schwann Cells in Human Leprosy

Infection and Immunity ◽

10.1128/iai.00454-10 ◽

2010 ◽

Vol 78 (11) ◽

pp. 4634-4643 ◽

Cited By ~ 20

Author(s):

Rosane M. B. Teles ◽

Stephan R. Krutzik ◽

Maria T. Ochoa ◽

Rosane B. Oliveira ◽

Euzenir N. Sarno ◽

...

Keyword(s):

Schwann Cell ◽

Peripheral Nerve ◽

Schwann Cells ◽

Primary Cultures ◽

Mycobacterium Leprae ◽

Microbial Pathogens ◽

Interleukin 4 ◽

Common Mechanism ◽

Specific Cell

ABSTRACT The ability of microbial pathogens to target specific cell types is a key aspect of the pathogenesis of infectious disease. Mycobacterium leprae, by infecting Schwann cells, contributes to nerve injury in patients with leprosy. Here, we investigated mechanisms of host-pathogen interaction in the peripheral nerve lesions of leprosy. We found that the expression of the C-type lectin, CD209, known to be expressed on tissue macrophages and to mediate the uptake of M. leprae, was present on Schwann cells, colocalizing with the Schwann cell marker, CNPase (2′,3′-cyclic nucleotide 3′-phosphodiesterase), along with the M. leprae antigen PGL-1 in the peripheral nerve biopsy specimens. In vitro, human CD209-positive Schwann cells, both from primary cultures and a long-term line, have a higher binding of M. leprae compared to CD209-negative Schwann cells. Interleukin-4, known to be expressed in skin lesions from multibacillary patients, increased CD209 expression on human Schwann cells and subsequent Schwann cell binding to M. leprae, whereas Th1 cytokines did not induce CD209 expression on these cells. Therefore, the regulated expression of CD209 represents a common mechanism by which Schwann cells and macrophages bind and take up M. leprae, contributing to the pathogenesis of leprosy.

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Activation of caspase-3 in β-amyloid-induced apoptosis of cultured rat cortical neurons

Brain Research ◽

10.1016/s0006-8993(99)01808-9 ◽

1999 ◽

Vol 842 (2) ◽

pp. 311-323 ◽

Cited By ~ 132

Author(s):

Jun Harada ◽

Masahiko Sugimoto

Keyword(s):

Cortical Neurons ◽

Caspase 3 ◽

Rat Cortical Neurons ◽

Β Amyloid ◽

Induced Apoptosis

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Aβ receptors specifically recognize molecular features displayed by fibril ends and neurotoxic oligomers

Nature Communications ◽

10.1038/s41467-021-23507-z ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Ladan Amin ◽

David A. Harris

Keyword(s):

Amyloid Β ◽

Super Resolution ◽

Structural Motif ◽

Aβ Oligomers ◽

Surface Receptors ◽

Molecular Features ◽

Molecular Determinant ◽

Receptor Interactions ◽

Aβ Fibrils ◽

Super Resolution Microscopy

AbstractSeveral cell-surface receptors for neurotoxic forms of amyloid-β (Aβ) have been described, but their molecular interactions with Aβ assemblies and their relative contributions to mediating Alzheimer’s disease pathology have remained uncertain. Here, we used super-resolution microscopy to directly visualize Aβ-receptor interactions at the nanometer scale. We report that one documented Aβ receptor, PrPC, specifically inhibits the polymerization of Aβ fibrils by binding to the rapidly growing end of each fibril, thereby blocking polarized elongation at that end. PrPC binds neurotoxic oligomers and protofibrils in a similar fashion, suggesting that it may recognize a common, end-specific, structural motif on all of these assemblies. Finally, two other Aβ receptors, FcγRIIb and LilrB2, affect Aβ fibril growth in a manner similar to PrPC. Our results suggest that receptors may trap Aβ oligomers and protofibrils on the neuronal surface by binding to a common molecular determinant on these assemblies, thereby initiating a neurotoxic signal.

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