Dysregulated Expression of Transposable Elements in TDP-43^M337V Human Motor Neurons That Recapitulate Amyotrophic...

Area of Science:

• Neuroscience
• Genetics
• Molecular Biology

Background:

• Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease affecting motor neurons.
• Mutations in TAR DNA binding protein 43 (TDP-43) are implicated in ALS pathogenesis, but molecular mechanisms remain unclear.
• Transposable elements (TEs) are mobile DNA sequences that can alter gene expression when dysregulated.

Purpose of the Study:

• To investigate the impact of TDP-43 mutations on gene expression and TE activity in human motor neurons.
• To determine if altered TE activity contributes to the molecular pathology of ALS.

Main Methods:

• RNA sequencing (RNA-Seq) was performed on induced human motor neurons (iMNs) with wild-type and mutant TDP-43 (TDP-43^M337V).
• Bioinformatic analyses were employed to assess changes in gene expression and TE transcription.
• Correlation analyses were conducted between TE activity and gene expression pathways.

Main Results:

• TDP-43^M337V mutations induced global alterations in gene expression and TE levels in iMNs.
• Significant overlap was observed between genetic pathways and TE activity, suggesting TEs regulate gene expression.
• TE dysregulation correlated with genes involved in extracellular matrix and RNA processing, pathways critical in ALS.

Conclusions:

• Loss of TE regulation is a key feature of TDP-43 mutations in human motor neurons.
• TEs are critical regulatory sequences that contribute to ALS neurodegeneration.
• Altered TE activity represents a potential therapeutic target for ALS.