Live Neuron High-Content Screening Reveals Synaptotoxic Activity in Alzheimer Mouse Model Homogenates

• Published in: Scientific reports 2020-02, Vol.10 (1), p.3412, Article 3412
• Main Authors: Jiang, Hao, Esparza, Thomas J., Kummer, Terrance T., Zhong, Haining, Rettig, Jens, Brody, David L.
• Format: Article
• Language: English
• Subjects: 631/1647/2163; 631/1647/245; 631/378/1689/1283; 631/378/1689/132/1283; 631/378/1689/364; 692/699/375/132/1283; 692/699/375/365/1283; Alzheimer Disease - genetics; Alzheimer Disease - metabolism; Alzheimer Disease - pathology; Alzheimer's disease; Amyloid beta-Peptides - genetics; Amyloid beta-Peptides - metabolism; Animals; Automation; Chromatography; Disease Models, Animal; Disks Large Homolog 4 Protein - genetics; Disks Large Homolog 4 Protein - metabolism; Humanities and Social Sciences; Image processing; Mice; Mice, Knockout; Molecular modelling; Molecular weight; multidisciplinary; Neurodegenerative diseases; Neuroimaging; Neurons; Neurons - metabolism; Neurons - pathology; Physiology; Postsynaptic density proteins; Protective coatings; Proteins; Science; Science (multidisciplinary); Synaptic plasticity; Synaptogenesis; Therapeutic applications; Toxicity; Vesicle-Associated Membrane Protein 2 - genetics; Vesicle-Associated Membrane Protein 2 - metabolism
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-60118-y

Accurate quantification of synaptic changes is essential for understanding the molecular mechanisms of synaptogenesis, synaptic plasticity, and synaptic toxicity. Here we demonstrate a robust high-content imaging method for the assessment of synaptic changes and apply the method to brain homogenates from an Alzheimer’s disease mouse model. Our method uses serial imaging of endogenous fluorescent labeled presynaptic VAMP2 and postsynaptic PSD95 in long-term cultured live primary neurons in 96 well microplates, and uses automatic image analysis to quantify the number of colocalized mature synaptic puncta for the assessment of synaptic changes in live neurons. As a control, we demonstrated that our synaptic puncta assay is at least 10-fold more sensitive to the toxic effects of glutamate than the MTT assay. Using our assay, we have compared synaptotoxic activities in size-exclusion chromatography fractioned protein samples from 3xTg-AD mouse model brain homogenates. Multiple synaptotoxic activities were found in high and low molecular weight fractions. Amyloid-beta immunodepletion alleviated some but not all of the synaptotoxic activities. Although the biochemical entities responsible for the synaptotoxic activities have yet to be determined, these proof-of-concept results demonstrate that this novel assay may have many potential mechanistic and therapeutic applications.