Selective Silencing of TDP-43 P. G376D Mutation Reverses Key Amyotrophic Lateral Sclerosis-Related Cellular Deficits

Area of Science:

• Neuroscience
• Genetics
• Molecular Biology

Background:

• Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease with no cure.
• Familial ALS can be caused by dominant mutations in the TARDBP gene, specifically the p.G376D substitution in TDP-43.
• This mutation leads to TDP-43 mislocalization, aggregation, and cellular dysfunction in motor neurons.

Purpose of the Study:

• To investigate the therapeutic potential of an allele-specific small interfering RNA (siRNA) targeting the TDP-43 G376D mutation.
• To assess the siRNA's efficacy in reversing ALS-associated pathological phenotypes in patient-derived motor neurons.

Main Methods:

• Developed an siRNA to specifically target and silence the mutant TARDBP allele.
• Utilized induced pluripotent stem cells (iPSCs) to generate motor neurons from ALS patients carrying the G376D mutation.
• Treated iPSC-derived motor neurons with the siRNA and evaluated TDP-43 localization, aggregation, lysosomal function, mitochondrial function, oxidative stress, and cell viability.

Main Results:

• siRNA treatment significantly reduced TDP-43 mislocalization and aggregation in motor neurons.
• The therapy enhanced lysosomal function and improved cell viability.
• siRNA administration decreased oxidative stress levels in the affected motor neurons.

Conclusions:

• The allele-specific siRNA effectively reverses key cellular deficits associated with the TDP-43 G376D mutation in motor neurons.
• This siRNA represents a promising therapeutic candidate for targeted treatment of familial ALS patients with this specific mutation.