ALS-linked TDP-43 mutations produce aberrant RNA splicing and adult-onset motor neuron disease without aggregation or loss of nuclear TDP-43

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 110; no. 8; pp. E736 - E745
• Main Authors: Arnold, Eveline S., Ling, Shuo-Chien, Huelga, Stephanie C., Lagier-Tourenne, Clotilde, Polymenidou, Magdalini, Ditsworth, Dara, Kordasiewicz, Holly B., McAlonis-Downes, Melissa, Platoshyn, Oleksandr, Parone, Philippe A., Da Cruz, Sandrine, Clutario, Kevin M., Swing, Debbie, Tessarollo, Lino, Marsala, Martin, Shaw, Christopher E., Yeo, Gene W., Cleveland, Don W.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 19.02.2013; National Acad Sciences
• Series: PNAS Plus
• Subjects: alternative splicing; Amyotrophic lateral sclerosis; Amyotrophic Lateral Sclerosis - genetics; Amyotrophic Lateral Sclerosis - metabolism; Amyotrophic Lateral Sclerosis - physiopathology; Animals; Binding sites; Biological Sciences; cell death; Cell Nucleus - metabolism; death; Deoxyribonucleic acid; DNA; DNA-binding proteins; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; exons; humans; Mice; Mice, Transgenic; microarray technology; motor neurons; Mutants; Mutation; Neurons; PNAS Plus; Proteins; Real-Time Polymerase Chain Reaction; RNA; RNA Splicing; Rodents; Ubiquitination
• ISSN: 0027-8424; 1091-6490; 1091-6490
• DOI: 10.1073/pnas.1222809110

Transactivating response region DNA binding protein (TDP-43) is the major protein component of ubiquitinated inclusions found in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) with ubiquitinated inclusions. Two ALS-causing mutants (TDP-43 Q³³¹ᴷ and TDP-43 ᴹ³³⁷ⱽ), but not wild-type human TDP-43, are shown here to provoke age-dependent, mutant-dependent, progressive motor axon degeneration and motor neuron death when expressed in mice at levels and in a cell type-selective pattern similar to endogenous TDP-43. Mutant TDP-43-dependent degeneration of lower motor neurons occurs without: (i) loss of TDP-43 from the corresponding nuclei, (ii) accumulation of TDP-43 aggregates, and (iii) accumulation of insoluble TDP-43. Computational analysis using splicing-sensitive microarrays demonstrates alterations of endogenous TDP-43–dependent alternative splicing events conferred by both human wild-type and mutant TDP-43 Q³³¹ᴷ, but with high levels of mutant TDP-43 preferentially enhancing exon exclusion of some target pre-mRNAs affecting genes involved in neurological transmission and function. Comparison with splicing alterations following TDP-43 depletion demonstrates that TDP-43 Q³³¹ᴷ enhances normal TDP-43 splicing function for some RNA targets but loss-of-function for others. Thus, adult-onset motor neuron disease does not require aggregation or loss of nuclear TDP-43, with ALS-linked mutants producing loss and gain of splicing function of selected RNA targets at an early disease stage.