Does TDP-43 recruitment to stress granules (SGs) play a key role in ALS/FTD pathogenesis and does this present an opportunity for gene therapy?

Background: The aggregation of TDP-43 protein into insoluble cytoplasmic inclusions is the hallmark pathology in ~95% of ALS and 60% of FTD cases. TDP-43 is an RNA binding protein, which under oxidative and osmotic cellular stressors is recruited to SGs where they could form toxic oligomers. TDP-43 transgenic mice recapitulate pathological features of ALS/FTD in vivo and in organotypic spinal cord slice cultures.
Hypothesis: That suppression of SG formation will inhibit TDP-43 aggregation and reduce toxicity.
Primary aims:
1. Establish the temporal sequence of neurodegenerative changes in cortical and spinal cord slice cultures.
2. Define the temporal sequence of TDP-43 recruitment to SGs in spinal cord motor neurons in slice cultures.
3. Knock down key stress granule proteins using antisense and measure SG formation in slice cultures.
4. Knock down stress granule proteins using antisense and monitor TDP-43 recruitment and toxicity in cultures.
5. Knock down key stress granule proteins in transgenic mice using intraventricular injection of antisense and monitor the effects on cognitive and motor phenotype.