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Degeneration of axons in spinal white matter in G93A mSOD1 mouse characterized by NFL and alpha internexin immunoreactivity
journal contribution
posted on 2023-05-17, 14:32 authored by Anna KingAnna King, Catherine BlizzardCatherine Blizzard, Katherine SouthamKatherine Southam, James VickersJames Vickers, Tracey DicksonTracey DicksonAxonal degeneration is a prominent feature of amyotrophic lateral sclerosis (ALS) both in lower motor nerves as well as descending white matter axons in the spinal cord of human patients. Although the pathology of lower motor axonal degeneration has been described in both human ALS and related transgenic animal models, few studies have examined the pathological features of descending axon degeneration, particularly in mouse models of ALS. We have examined the degeneration of white matter tracts in the G93A mutant superoxide dismutase-1 (mSOD1+) mouse spinal cord white matter from 12 weeks of age to end-stage disease. In a G93A mSOD1 mouse model where green fluorescent protein was expressed in neurons (mSOD1+/GFP+), degeneration of white matter tracts was present from the ventral to dorsolateral funiculi. This pattern of axonal pathology occurred from 16 weeks of age. However, the dorsal funiculus, the site of the major corticospinal tract in mice, showed relatively less degeneration. Immunohistochemical analysis demonstrated that the neurofilament light chain (NFL) and neuronal intermediate filament protein alpha-internexin accumulated in axon swellings in the spinal white matter. Increased levels of alpha-internexin protein, in mSOD1+ mouse spinal cord tissue, were demonstrated by Western blotting. In contrast, degenerating axons did not show obvious accumulations of neurofilament medium and heavy chain proteins (NFM and NFH). These data suggest that white matter degeneration in this mouse model of ALS is widespread and involves a specific molecular signature, particularly the accumulation of NFL and alpha-internexin proteins.
History
Publication title
Brain ResearchVolume
1465Pagination
90-100ISSN
0006-8993Department/School
Tasmanian School of MedicinePublisher
Elsevier Science BvPlace of publication
PO Box 211, Amsterdam, Netherlands, 1000 AeRights statement
Copyright 2012 Elsevier.Repository Status
- Restricted