Deficits in axonal transport precede ALS symptoms in vivo.
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ABSTRACT:
SUBMITTER: Bilsland LG
PROVIDER: S-EPMC2996651 | biostudies-literature | 2010 Nov
REPOSITORIES: biostudies-literature
Publications
Deficits in axonal transport precede ALS symptoms in vivo.
Bilsland Lynsey G LG Sahai Erik E Kelly Gavin G Golding Matthew M Greensmith Linda L Schiavo Giampietro G
Proceedings of the National Academy of Sciences of the United States of America 20101108 47
ALS is a fatal neurodegenerative disease characterized by selective motor neuron death resulting in muscle paralysis. Mutations in superoxide dismutase 1 (SOD1) are responsible for a subset of familial cases of ALS. Although evidence from transgenic mice expressing human mutant SOD1(G93A) suggests that axonal transport defects may contribute to ALS pathogenesis, our understanding of how these relate to disease progression remains unclear. Using an in vivo assay that allows the characterization o ...[more]
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Project description:ObjectiveThe objective of this study is to develop a novel method for monitoring the integrity of motor neurons in vivo by quantifying net retrograde axonal transport.MethodsThe method uses single photon emission computed tomography to quantify retrograde transport to spinal cord of tetanus toxin fragment C (125 I-TTC) following intramuscular injection. We characterized the transport profiles in 3 transgenic mouse models carrying amyotrophic lateral sclerosis (ALS)-associated genes, aging mice, and SOD1G93A transgenic mice following CRISPR/Cas9 gene editing. Lastly, we studied the effect of prior immunization of tetanus toxoid on the transport profile of TTC.ResultsThis technique defines a quantitative profile of net retrograde axonal transport of TTC in living mice. The profile is distinctly abnormal in transgenic SOD1G93A mice as young as 65 days (presymptomatic) and worsens with disease progression. Moreover, this method detects a distinct therapeutic benefit of gene editing in transgenic SOD1G93A mice well before other clinical parameters (eg, grip strength) show improvement. Symptomatic transgenic PFN1C71G/C71G ALS mice display gross reductions in net retrograde axonal transport, which is also disturbed in asymptomatic mice harboring a human C9ORF72 transgene with an expanded GGGGCC repeat motif. In wild-type mice, net retrograde axonal transport declines with aging. Lastly, prior immunization with tetanus toxoid does not preclude use of this assay.InterpretationThis assay of net retrograde axonal transport has broad potential clinical applications and should be particularly valuable as a physiological biomarker that permits early detection of benefit from potential therapies for motor neuron diseases. ANN NEUROL 2022;91:716-729.
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