Rapid and Robust Multi-Phenotypic Assay System for ALS Using Human iPS Cells with Mutations in Causative Genes

Area of Science:

• Neuroscience
• Stem Cell Biology
• Genetics

Background:

• Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by motor neuron loss.
• Current treatments for ALS are limited, necessitating the development of new therapeutic strategies.
• Induced pluripotent stem cells (iPSCs) offer a promising platform for disease modeling and drug discovery.

Purpose of the Study:

• To establish a high-throughput screening system for identifying potential ALS therapeutics using iPSC-derived motor neurons.
• To investigate the efficacy of rapamycin and retigabine in ameliorating ALS phenotypes in vitro.
• To explore the role of autophagy in ALS pathogenesis and neuronal survival.

Main Methods:

• Generation of motor neurons from iPSCs using a Tet-On-dependent transcription factor expression system.
• Introduction of ALS-associated mutations (FUS, SOD1) into iPSC-derived motor neurons.
• Phenotypic analysis using calcium imaging and multiple electrode array (MEA) recordings.
• Assessment of drug efficacy (rapamycin, retigabine) on neuronal function and survival.

Main Results:

• iPSC-derived motor neurons carrying FUS or SOD1 mutations exhibited abnormal protein accumulation and hyperexcitability.
• Rapamycin treatment ameliorated protein accumulation, reduced hyperexcitability, and suppressed neuronal death.
• Retigabine effectively reduced neuronal hyperexcitability.
• The developed culture system successfully recapitulated key ALS phenotypes.

Conclusions:

• The iPSC-based screening system provides a robust platform for ALS drug discovery.
• Rapamycin shows therapeutic potential for ALS by promoting protein aggregate clearance via autophagy.
• This system facilitates the development of personalized medicine approaches for ALS and other motor neuron diseases.