Amyotrophic lateral sclerosis (ALS) is a uniformly lethal, age-dependent neurodegenerative disorder with a typical survival of 2-5 years. With the possible exception of reduced numbers of copies of the SMN gene, or the presence of the SOD1A4V gene mutation, genetic factors that influence survival in ALS have not been described. We recently reported that survival in sporadic ALS is enhanced by genetic variants that reduce expression of KIFAP3, a protein constituent of a kinesin II complex that mediates fast anterograde axonal transport. Homozygotes for the favorable allele have a survival advantage of 14.0 months, a substantial improvement (~42%) that surpasses the magnitude of benefit of the single drug (riluzole) that is FDA approved for ALS in ALS. A recent study documents that KIFAP3 binds misfolded SOD1G93A in ALS mice and is co-localized with the mutant SOD1 protein in aggregates both in the SOD1G93A mouse and in spinal cords of ALS patients bearing mutations in the SOD1 gene. These findings support the view that axonal transport proteins, and KIFAP3 in particular, are determinants of motor neuron viability. This proposal will investigate the mechanisms by which decreased expression of KIFAP3 increases survival in ALS.
The Specific Aims of this proposal are to: (1) Analyze the interactions between KIFAP3, SOD1 and other cargoes in human sporadic ALS spinal cords. Hypothesis: Misfolded, wild-type SOD1 binds to KIFAP3 in sporadic ALS but not control spinal cords. (2) Determine the effect of reduced KIFAP3 expression on motor neuron viability and survival in transgenic SOD1G93A mice. Hypothesis: By analogy with survival in human ALS, motor neuron viability and survival in transgenic ALS mice will be enhanced by reduced expression of KIFAP3. (3) Analyze the interactions between KIFAP3, SOD1 and other cargoes in spinal cord from ALS and control mice with normal and reduced levels of KIFAP3. Hypothesis: Decreased expression of KIFAP3 will alter the types and quantities of cargoes transported by KIFAP3. (4) Determine the influence of altered expression levels of KIFAP3 on axonal transport rates in embryonic motor neurons from ALS and control mice. Hypothesis: Altered levels of KIFAP3 expression are not determinants of axonal transport rates. Our proposed studies will elucidate the mechanisms whereby KIFAP3 expression modulates survival in ALS. In the long term, understanding how KIFAP3 influences survival will facilitate the development of therapies to extend the lifespan of ALS patients.

Public Health Relevance

Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, is a uniformly lethal, age-dependent neurodegenerative disorder with a typical survival of 2 to 5 years. Through our efforts, we have identified a gene which can influence the survival advantage of sporadic ALS by 14.0 months, a substantial increment (42%) in this disease. The purpose of this proposal is to understand how this gene influences survival, which will aid in the development of treatment strategies to extend the lifespan of patients afflicted with ALS.

National Institute of Health (NIH)
National Institute of Neurological Disorders and Stroke (NINDS)
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Cell Death and Injury in Neurodegeneration Study Section (CDIN)
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Gubitz, Amelie
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University of Massachusetts Medical School Worcester
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Brenner, David; Yilmaz, Rüstem; Müller, Kathrin et al. (2018) Hot-spot KIF5A mutations cause familial ALS. Brain 141:688-697
White, Matthew A; Kim, Eosu; Duffy, Amanda et al. (2018) TDP-43 gains function due to perturbed autoregulation in a Tardbp knock-in mouse model of ALS-FTD. Nat Neurosci 21:552-563
Fil, Daniel; DeLoach, Abigail; Yadav, Shilpi et al. (2017) Mutant Profilin1 transgenic mice recapitulate cardinal features of motor neuron disease. Hum Mol Genet 26:686-701
Cooper-Knock, Johnathan; Robins, Henry; Niedermoser, Isabell et al. (2017) Targeted Genetic Screen in Amyotrophic Lateral Sclerosis Reveals Novel Genetic Variants with Synergistic Effect on Clinical Phenotype. Front Mol Neurosci 10:370
Kubat Öktem, Elif; Mruk, Karen; Chang, Joshua et al. (2016) Mutant SOD1 protein increases Nav1.3 channel excitability. J Biol Phys 42:351-70
Peters, Owen M; Cabrera, Gabriela Toro; Tran, Helene et al. (2015) Human C9ORF72 Hexanucleotide Expansion Reproduces RNA Foci and Dipeptide Repeat Proteins but Not Neurodegeneration in BAC Transgenic Mice. Neuron 88:902-909
Peters, Owen M; Ghasemi, Mehdi; Brown Jr, Robert H (2015) Emerging mechanisms of molecular pathology in ALS. J Clin Invest 125:1767-79
Smith, Bradley N; Vance, Caroline; Scotter, Emma L et al. (2015) Novel mutations support a role for Profilin 1 in the pathogenesis of ALS. Neurobiol Aging 36:1602.e17-27
Smith, Bradley N; Ticozzi, Nicola; Fallini, Claudia et al. (2014) Exome-wide rare variant analysis identifies TUBA4A mutations associated with familial ALS. Neuron 84:324-31
Seijffers, Rhona; Zhang, Jiangwen; Matthews, Jonathan C et al. (2014) ATF3 expression improves motor function in the ALS mouse model by promoting motor neuron survival and retaining muscle innervation. Proc Natl Acad Sci U S A 111:1622-7

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