Drug screening for ALS using patient-specific induced pluripotent stem cells

Area of Science:

• Neuroscience
• Stem Cell Biology
• Genetics

Background:

• Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease.
• Drug discovery for ALS is limited by patient-derived motor neuron access and disease models.
• Familial ALS cases often involve mutations in the Tar DNA binding protein-43 (TDP-43) gene.

Purpose of the Study:

• To create a disease model for ALS using patient-derived induced pluripotent stem cells (iPSCs).
• To investigate the cellular and molecular pathology of ALS in patient-specific motor neurons.
• To screen for potential therapeutic compounds that can correct ALS-related motor neuron dysfunction.

Main Methods:

• Generation of motor neurons from iPSCs of familial ALS patients with TDP-43 mutations.
• Characterization of iPSC-derived motor neurons for cytosolic aggregates, neurite length, and TDP-43 protein insolubility.
• Expression array analysis to identify gene expression changes in ALS motor neurons.
• Screening of chemical compounds, including anacardic acid, for therapeutic effects.

Main Results:

• ALS patient-derived iPSC motor neurons exhibited TDP-43 aggregates and shorter neurites, mimicking disease pathology.
• Increased insoluble mutant TDP-43 protein was observed, bound to the spliceosomal factor SNRPB2.
• Gene expression analysis revealed altered RNA metabolism and cytoskeletal protein pathways.
• Anacardic acid, a histone acetyltransferase inhibitor, rescued the abnormal motor neuron phenotype.

Conclusions:

• ALS patient-derived iPSC motor neurons provide a valuable in vitro model for studying disease pathogenesis.
• This model can be utilized for screening potential drug candidates for ALS treatment.
• Targeting pathways involving TDP-43 and RNA metabolism may offer therapeutic strategies for ALS.