Restorative Effects of the TrkB agonist 7,8-Dihydroxyflavone on Neuronal Network Activity in an in vitro model of Huntington's disease

Abstract ß-Synuclein (ß-Syn) has long been considered to be an attenuator for the neuropathological effects caused by the Parkinson’s disease-related α-Synuclein (α-Syn) protein. However, recent studies demonstrated that overabundant ß-Syn can form aggregates and induce neurodegeneration in CNS neurons in vitro and in vivo, albeit at a slower pace as compared to α-Syn. Here we demonstrate that ß-Syn mutants V70M, detected in a sporadic case of Dementia with Lewy Bodies (DLB), and P123H, detected in a familial case of DLB, robustly aggravate the neurotoxic potential of ß-Syn. Intriguingly, the two mutations trigger mutually exclusive pathways. ß-Syn V70M enhances morphological mitochondrial deterioration and degeneration of dopaminergic and non-dopaminergic neurons, but has no influence on neuronal network activity. Conversely, ß-Syn P123H silences neuronal network activity, but does not aggravate neurodegeneration. ß-Syn WT, V70M and P123H formed proteinase K (PK) resistant intracellular fibrils within neurons, albeit with less stable C-termini as compared to α-Syn. Under cell free conditions, ß-Syn V70M demonstrated a much slower pace of fibril formation as compared to WT ß-Syn, and P123H fibrils present with a unique phenotype characterized by large numbers of short, truncated fibrils. Thus, it is possible that V70M and P123H cause structural alterations in ß-Syn, that are linked to their distinct neuropathological profiles. The extent of the lesions caused by these neuropathological profiles is almost identical to that of overabundant α-Syn, and thus likely to be directly involved into etiology of DLB. Over all, this study provides insights into distinct disease mechanisms caused by mutations of ß-Syn.

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Influence of albumin dialysis (MARS) on neuronal network activity in vitro

Zeitschrift für Gastroenterologie ◽

10.1055/s-2001-919046 ◽

2001 ◽

Vol 39 ◽

pp. 40-40

Author(s):

J Loock ◽

J Stange ◽

S Mitzner ◽

R Schmidt ◽

E W Keefer ◽

...

Keyword(s):

Neuronal Network ◽

Network Activity ◽

Albumin Dialysis ◽

Neuronal Network Activity

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IMAGING | Functional Imaging of Neuronal Network Activity in Living Human Brain Tissues In Vitro

Encyclopedia of Basic Epilepsy Research ◽

10.1016/b978-012373961-2.00275-7 ◽

2009 ◽

pp. 535-539

Author(s):

A. Gorji ◽

E.-J. Speckmann

Keyword(s):

Human Brain ◽

Functional Imaging ◽

Neuronal Network ◽

Network Activity ◽

Neuronal Network Activity ◽

Brain Tissues

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Pharmacological intervention to restore connectivity deficits of neuronal networks derived from ASD patient iPSC with a TSC2 mutation

Molecular Autism ◽

10.1186/s13229-020-00391-w ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Mouhamed Alsaqati ◽

Vivi M. Heine ◽

Adrian J. Harwood

Keyword(s):

Neuronal Network ◽

Electrode Array ◽

Network Connectivity ◽

Autism Spectrum ◽

Network Activity ◽

Inhibitory Synapses ◽

Pharmacological Intervention ◽

Spatial Connectivity ◽

Neuronal Network Activity

Abstract Background Tuberous sclerosis complex (TSC) is a rare genetic multisystemic disorder resulting from autosomal dominant mutations in the TSC1 or TSC2 genes. It is characterised by hyperactivation of the mechanistic target of rapamycin complex 1 (mTORC1) pathway and has severe neurodevelopmental and neurological components including autism, intellectual disability and epilepsy. In human and rodent models, loss of the TSC proteins causes neuronal hyperexcitability and synaptic dysfunction, although the consequences of these changes for the developing central nervous system are currently unclear. Methods Here we apply multi-electrode array-based assays to study the effects of TSC2 loss on neuronal network activity using autism spectrum disorder (ASD) patient-derived iPSCs. We examine both temporal synchronisation of neuronal bursting and spatial connectivity between electrodes across the network. Results We find that ASD patient-derived neurons with a functional loss of TSC2, in addition to possessing neuronal hyperactivity, develop a dysfunctional neuronal network with reduced synchronisation of neuronal bursting and lower spatial connectivity. These deficits of network function are associated with elevated expression of genes for inhibitory GABA signalling and glutamate signalling, indicating a potential abnormality of synaptic inhibitory–excitatory signalling. mTORC1 activity functions within a homeostatic triad of protein kinases, mTOR, AMP-dependent protein Kinase 1 (AMPK) and Unc-51 like Autophagy Activating Kinase 1 (ULK1) that orchestrate the interplay of anabolic cell growth and catabolic autophagy while balancing energy and nutrient homeostasis. The mTOR inhibitor rapamycin suppresses neuronal hyperactivity, but does not increase synchronised network activity, whereas activation of AMPK restores some aspects of network activity. In contrast, the ULK1 activator, LYN-1604, increases the network behaviour, shortens the network burst lengths and reduces the number of uncorrelated spikes. Limitations Although a robust and consistent phenotype is observed across multiple independent iPSC cultures, the results are based on one patient. There may be more subtle differences between patients with different TSC2 mutations or differences of polygenic background within their genomes. This may affect the severity of the network deficit or the pharmacological response between TSC2 patients. Conclusions Our observations suggest that there is a reduction in the network connectivity of the in vitro neuronal network associated with ASD patients with TSC2 mutation, which may arise via an excitatory/inhibitory imbalance due to increased GABA-signalling at inhibitory synapses. This abnormality can be effectively suppressed via activation of ULK1.

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Curcumin-Loaded Nanoparticles Based on Amphiphilic Hyaluronan-Conjugate Explored as Targeting Delivery System for Neurodegenerative Disorders

International Journal of Molecular Sciences ◽

10.3390/ijms21228846 ◽

2020 ◽

Vol 21 (22) ◽

pp. 8846

Author(s):

Giuseppe Pepe ◽

Enrica Calce ◽

Valentina Verdoliva ◽

Michele Saviano ◽

Vittorio Maglione ◽

...

Keyword(s):

Huntington's Disease ◽

Huntington’S Disease ◽

Delivery System ◽

Neurodegenerative Disorders ◽

Natural Polysaccharide ◽

Promising Therapeutic Approach ◽

Targeting Delivery ◽

Effective Delivery ◽

Vitro Model

Identification of molecules able to promote neuroprotective mechanisms can represent a promising therapeutic approach to neurodegenerative disorders including Huntington’s disease. Curcumin is an antioxidant and neuroprotective agent, even though its efficacy is limited by its poor absorption, rapid metabolism, systemic elimination, and limited blood–brain barrier (BBB) permeability. Herein, we report on novel biodegradable curcumin-containing nanoparticles to favor the compound delivery and potentially enhance its brain bioavailability. The prepared hyaluronan-based materials able to self-assemble in stable spherical nanoparticles, consist of natural fatty acids chemically conjugated to the natural polysaccharide. The aim of this study is to provide a possible effective delivery system for curcumin with the expectation that, after having released the drug at the specific site, the biopolymer can degrade to nontoxic fragments before renal excretion, since all the starting materials are provided by natural resource. Our findings demonstrate that curcumin-encapsulated nanoparticles enter the cells and reduce their susceptibility to apoptosis in an in vitro model of Huntington’s disease.

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