Imaging organelle transport in primary hippocampal neurons treated with amyloid-β oligomers

Introduction: Schisandrin which is derived from Schisandra chinensis has shown multiple pharmacological effects on various diseases including Alzheimer’s disease (AD). It is demonstrated that mitochondrial dysfunction plays an essential role in the pathogenesis of neurodegenerative disorders. Objective: Our study aims to investigate the effects of schisandrin on mitochondrial functions and metabolisms in primary hippocampal neurons. Methods: In our study, rat primary hippocampal neurons were isolated and treated with indicated dose of amyloid β1–42 (Aβ1–42) oligomer to establish a cell model of AD in vitro. Schisandrin (2 μg/mL) was further subjected to test its effects on mitochondrial function, energy metabolism, mitochondrial biogenesis, and dynamics in the Aβ1–42 oligomer-treated neurons. Results and Conclusions: Our findings indicated that schisandrin significantly alleviated the Aβ1–42 oligomer-induced loss of mitochondrial membrane potential and impaired cytochrome c oxidase activity. Additionally, the opening of mitochondrial permeability transition pore and release of cytochrome c were highly restricted with schisandrin treatment. Alterations in cell viability, ATP production, citrate synthase activity, and the expressions of glycolysis-related enzymes demonstrated the relief of defective energy metabolism in Aβ-treated neurons after the treatment of schisandrin. For mitochondrial biogenesis, elevated expression of peroxisome proliferator-activated receptor γ coactivator along with promoted mitochondrial mass was found in schisandrin-treated cells. The imbalance in the cycle of fusion and fission was also remarkably restored by schisandrin. In summary, this study provides novel mechanisms for the protective effect of schisandrin on mitochondria-related functions.

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Cell-derived soluble oligomers of human amyloid-β peptides disturb cellular homeostasis and induce apoptosis in primary hippocampal neurons

Journal of Neural Transmission ◽

10.1007/s00702-009-0311-0 ◽

2009 ◽

Vol 116 (12) ◽

pp. 1561-1569 ◽

Cited By ~ 24

Author(s):

Ting-Ting Yang ◽

Chao-Tien Hsu ◽

Yu-Min Kuo

Keyword(s):

Hippocampal Neurons ◽

Amyloid Β ◽

Cellular Homeostasis ◽

Primary Hippocampal Neurons

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Sub-lethal levels of amyloid β-peptide oligomers decrease non-transferrin-bound iron uptake and do not potentiate iron toxicity in primary hippocampal neurons

BioMetals ◽

10.1007/s10534-012-9545-7 ◽

2012 ◽

Vol 25 (4) ◽

pp. 805-813 ◽

Cited By ~ 6

Author(s):

C. D. SanMartín ◽

A. C. Paula-Lima ◽

C. Hidalgo ◽

M. T. Núñez

Keyword(s):

Iron Uptake ◽

Hippocampal Neurons ◽

Amyloid Β ◽

Iron Toxicity ◽

Amyloid Β Peptide ◽

Primary Hippocampal Neurons

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Selenium Compounds Prevent Amyloid β-Peptide Neurotoxicity in Rat Primary Hippocampal Neurons

Neurochemical Research ◽

10.1007/s11064-013-1147-4 ◽

2013 ◽

Vol 38 (11) ◽

pp. 2359-2363 ◽

Cited By ~ 17

Author(s):

Gabriela Lorea Godoi ◽

Lisiane de Oliveira Porciúncula ◽

Janaína Fagundes Schulz ◽

Fernanda Neutzling Kaufmann ◽

João Batista da Rocha ◽

...

Keyword(s):

Hippocampal Neurons ◽

Amyloid Β ◽

Amyloid Β Peptide ◽

Selenium Compounds ◽

Primary Hippocampal Neurons

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Amyloid-β oligomers induce tau-independent disruption of BDNF axonal transport via calcineurin activation in cultured hippocampal neurons

Molecular Biology of the Cell ◽

10.1091/mbc.e12-12-0858 ◽

2013 ◽

Vol 24 (16) ◽

pp. 2494-2505 ◽

Cited By ~ 40

Author(s):

Elisa M. Ramser ◽

Kathlyn J. Gan ◽

Helena Decker ◽

Emily Y. Fan ◽

Matthew M. Suzuki ◽

...

Keyword(s):

Axonal Transport ◽

Hippocampal Neurons ◽

Glycogen Synthase ◽

Amyloid Β ◽

Protein Phosphatase 1 ◽

Organelle Transport ◽

Calcium Dependent ◽

Pathological Event ◽

Cultured Hippocampal Neurons

Disruption of fast axonal transport (FAT) is an early pathological event in Alzheimer's disease (AD). Soluble amyloid-β oligomers (AβOs), increasingly recognized as proximal neurotoxins in AD, impair organelle transport in cultured neurons and transgenic mouse models. AβOs also stimulate hyperphosphorylation of the axonal microtubule-associated protein, tau. However, the role of tau in FAT disruption is controversial. Here we show that AβOs reduce vesicular transport of brain-derived neurotrophic factor (BDNF) in hippocampal neurons from both wild-type and tau-knockout mice, indicating that tau is not required for transport disruption. FAT inhibition is not accompanied by microtubule destabilization or neuronal death. Significantly, inhibition of calcineurin (CaN), a calcium-dependent phosphatase implicated in AD pathogenesis, rescues BDNF transport. Moreover, inhibition of protein phosphatase 1 and glycogen synthase kinase 3β, downstream targets of CaN, prevents BDNF transport defects induced by AβOs. We further show that AβOs induce CaN activation through nonexcitotoxic calcium signaling. Results implicate CaN in FAT regulation and demonstrate that tau is not required for AβO-induced BDNF transport disruption.

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Misfolded amyloid-β-42 impairs the endosomal–lysosomal pathway

Cellular and Molecular Life Sciences ◽

10.1007/s00018-020-03464-4 ◽

2020 ◽

Vol 77 (23) ◽

pp. 5031-5043 ◽

Cited By ~ 3

Author(s):

Karen E. Marshall ◽

Devkee M. Vadukul ◽

Kevin Staras ◽

Louise C. Serpell

Keyword(s):

Neurodegenerative Diseases ◽

Real Time ◽

Hippocampal Neurons ◽

Amyloid Β ◽

Dependent Manner ◽

Potential Mechanism ◽

Protein Uptake ◽

Alexa Fluor ◽

Primary Hippocampal Neurons ◽

Oligomeric Forms

Abstract Misfolding and aggregation of proteins is strongly linked to several neurodegenerative diseases, but how such species bring about their cytotoxic actions remains poorly understood. Here we used specifically-designed optical reporter probes and live fluorescence imaging in primary hippocampal neurons to characterise the mechanism by which prefibrillar, oligomeric forms of the Alzheimer’s-associated peptide, Aβ42, exert their detrimental effects. We used a pH-sensitive reporter, Aβ42-CypHer, to track Aβ internalisation in real-time, demonstrating that oligomers are rapidly taken up into cells in a dynamin-dependent manner, and trafficked via the endo-lysosomal pathway resulting in accumulation in lysosomes. In contrast, a non-assembling variant of Aβ42 (vAβ42) assayed in the same way is not internalised. Tracking ovalbumin uptake into cells using CypHer or Alexa Fluor tags shows that preincubation with Aβ42 disrupts protein uptake. Our results identify a potential mechanism by which amyloidogenic aggregates impair cellular function through disruption of the endosomal–lysosomal pathway.

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Misfolded amyloid β-42 induced impairment of the endosomal-lysosomal pathway revealed by real-time optical monitoring

10.1101/598540 ◽

2019 ◽

Author(s):

Karen E Marshall ◽

Devkee Vadukul ◽

Kevin Staras ◽

Louise C Serpell

Keyword(s):

Real Time ◽

Hippocampal Neurons ◽

Amyloid Β ◽

Dependent Manner ◽

Optical Monitoring ◽

Potential Mechanism ◽

Protein Uptake ◽

Alexa Fluor ◽

Primary Hippocampal Neurons ◽

Oligomeric Forms

ABSTRACTMisfolding and aggregation of proteins is strongly linked to several neurodegenerative diseases but how such species bring about their cytotoxic actions remains poorly understood. Here we used specifically-designed optical reporter probes and live fluorescence imaging in primary hippocampal neurons to characterise the mechanism by which prefibrillar, oligomeric forms of the Alzheimer’s-associated peptide, Aβ42, exert their detrimental effects. We used a pH-sensitive reporter, Aβ42-CypHer, to track Aβ internalisation in real time, demonstrating that oligomers are rapidly taken up into cells in a dynamin-dependent manner, and trafficked via the endo-lysosomal pathway resulting in accumulation in lysosomes. In contrast, a non-assembling variant of Aβ42 (vAβ42) assayed in the same way is not internalised. Tracking ovalbumin uptake into cells using CypHer or Alexa Fluor tags shows that preincubation with Aβ42 significantly disrupts protein uptake. Our results identify a potential mechanism by which amyloidogenic aggregates directly impair cellular function through disruption of the endosomal-lysosomal pathway.

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