Degeneration of axons in spinal white matter in G93A mSOD1 mouse characterized by NFL and alpha-intemexin immunoreactivity

作者：King Anna E^*; Blizzard Catherine A; Southam Katherine A; Vickers James C; Dickson Tracey C

来源：Brain Research, 2012, 1465: 90-100.

DOI：10.1016/j.brainres.2012.05.018

• Axon degeneration
• Spinal cord
• Neuronal intermediate filament
• ALS

Axonal 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-intemexin accumulated in axon swellings in the spinal white matter. Increased levels of alpha-intemexin 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-intemexin proteins.

• 出版日期2012-7-17