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journal.pone.0176997.pdf (7.33 MB)

Mild and repetitive very mild axonal stretch injury triggers cystoskeletal mislocalization and growth cone collapse

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posted on 2023-05-19, 07:00 authored by Ying YapYing Yap, Anna KingAnna King, Rosanne Guijt, Jiang, T, Catherine BlizzardCatherine Blizzard, Michael BreadmoreMichael Breadmore, Tracey DicksonTracey Dickson
Diffuse axonal injury is a hallmark pathological consequence of non-penetrative traumatic brain injury (TBI) and yet the axonal responses to stretch injury are not fully understood at the cellular level. Here, we investigated the effects of mild (5%), very mild (0.5%) and repetitive very mild (2×0.5%) axonal stretch injury on primary cortical neurons using a recently developed compartmentalized in vitro model. We found that very mild and mild levels of stretch injury resulted in the formation of smaller growth cones at the tips of axons and a significantly higher number of collapsed structures compared to those present in uninjured cultures, when measured at both 24 h and 72 h post injury. Immunocytochemistry studies revealed that at 72 h following mild injury the axonal growth cones had a significantly higher colocalization of βIII tubulin and F-actin and higher percentage of collapsed morphology than those present following a very mild injury. Interestingly, cultures that received a second very mild stretch injury, 24 h after the first insult, had a further increased proportion of growth cone collapse and increased βIII tubulin and F-actin colocalization, compared with a single very mild injury at 72 h PI. In addition, our results demonstrated that microtubule stabilization of axons using brain penetrant Epothilone D (EpoD) (100 nM) resulted in a significant reduction in the number of fragmented axons following mild injury. Collectively, these results suggest that mild and very mild stretch injury to a very localized region of the cortical axon is able to trigger a degenerative response characterized by growth cone collapse and significant abnormal cytoskeletal rearrangement. Furthermore, repetitive very mild stretch injury significantly exacerbated this response. Results suggest that axonal degeneration following stretch injury involves destabilization of the microtubule cytoskeleton and hence treatment with EpoD reduced fragmentation. Together, these results contribute a better understanding of the pathogenesis of mild and repetitive TBI and highlight the therapeutic effect of microtubule targeted drugs on distal part of neurons using a compartmentalized culturing model.


Publication title

PLoS One





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School of Natural Sciences


Public Library of Science

Place of publication

San Francisco, CA 94111 United States

Rights statement

Copyright 2017 Yap et al. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0)

Repository Status

  • Open

Socio-economic Objectives

Clinical health not elsewhere classified

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