Nuclear transport dysfunction: a common theme in amyotrophic lateral sclerosis and frontotemporal dementia

Area of Science:

• Neuroscience
• Cell Biology
• Genetics

Background:

• Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are devastating neurodegenerative diseases.
• Both conditions share overlapping genetic origins and pathological features.
• A common cellular hallmark is the mislocalization and aggregation of nuclear proteins like TDP-43 and FUS.

Purpose of the Study:

• To investigate the convergence of genetic risk factors and aging on cellular pathways in ALS and FTD.
• To propose nucleocytoplasmic transport dysfunction as a unifying mechanism in ALS/FTD pathogenesis.
• To link specific genetic mutations and aging to the hallmark protein aggregation observed in these diseases.

Main Methods:

• Review of recent studies on genetic risk factors for ALS/FTD.
• Analysis of cellular pathways perturbed by these genetic factors.
• Focus on the role of nucleocytoplasmic transport.

Main Results:

• Genetic mutations (e.g., in FUS) and hexanucleotide expansions (e.g., in C9orf72) converge on nucleocytoplasmic transport.
• Aging also appears to impair this critical cellular transport process.
• Impaired nucleocytoplasmic transport leads to the cytoplasmic aggregation of TDP-43 and FUS.

Conclusions:

• Nucleocytoplasmic transport dysfunction is a central mechanism in ALS and FTD.
• Mutations in FUS, C9orf72 expansions, and aging collectively disrupt this transport.
• This disruption explains the characteristic cytoplasmic aggregation of TDP-43/FUS in ALS/FTD patients.