Theme 3 In vitro experimental models.

Area of Science:

• Neuroscience
• Genetics
• Molecular Biology

Background:

• Genetic mutations explain 60% of Amyotrophic Lateral Sclerosis (ALS) cases, leaving 40% of families with unidentified causative genes.
• Remaining ALS families often exhibit non-Mendelian inheritance, posing challenges for traditional genetic analysis.
• In vitro and in vivo studies are crucial for validating novel ALS candidate genes.

Purpose of the Study:

• To develop and validate an in vitro functional pipeline for discovering and validating novel Amyotrophic Lateral Sclerosis (ALS) candidate genes.
• To identify genes responsible for familial ALS cases where known mutations are absent.

Main Methods:

• A panel of cell-based assays including immunofluorescence, flow cytometry, and western blotting were employed.
• Assays assessed toxicity, neuronal inclusion formation, TDP-43 interaction, protein degradation defects, and detergent-insoluble fraction accumulation.
• Immunohistochemistry and immunofluorescence were used to examine candidate presence in ALS patient spinal cord tissues.

Main Results:

• The pipeline prioritized two candidate genes from an ALS family lacking known mutations.
• Variants in these two genes significantly increased cellular toxicity, formed detergent-insoluble inclusions, and co-aggregated with TDP-43.
• One candidate co-localized with TDP-43 inclusions in post-mortem tissues from sporadic ALS patients.

Conclusions:

• The study successfully demonstrated the utility of a functional prioritization pipeline for identifying novel ALS candidate genes.
• Two novel candidate genes were prioritized, showing capacity to induce key ALS pathologies.
• These findings provide new diagnostic and therapeutic targets for Amyotrophic Lateral Sclerosis (ALS) research and treatment development.