1. Functional Characterization of Neurofilament Light Splicing and Misbalance in Zebrafish.
- Author
-
Demy DL, Campanari ML, Munoz-Ruiz R, Durham HD, Gentil BJ, and Kabashi E
- Subjects
- Animals, Atrophy, Axons metabolism, Axons pathology, Cell Line, DNA-Binding Proteins metabolism, Embryo, Nonmammalian metabolism, Gene Expression Regulation, Developmental, Humans, Motor Activity, Motor Neurons metabolism, Motor Neurons pathology, Neurofilament Proteins metabolism, Phenotype, Polymerization, Sequence Homology, Amino Acid, Zebrafish embryology, Zebrafish Proteins metabolism, Neurofilament Proteins genetics, Postural Balance genetics, RNA Splicing genetics, Zebrafish genetics, Zebrafish Proteins genetics
- Abstract
Neurofilaments (NFs), a major cytoskeletal component of motor neurons, play a key role in the differentiation, establishment and maintenance of their morphology and mechanical strength. The de novo assembly of these neuronal intermediate filaments requires the presence of the neurofilament light subunit (NEFL), whose expression is reduced in motor neurons in amyotrophic lateral sclerosis (ALS). This study used zebrafish as a model to characterize the NEFL homologue neflb , which encodes two different isoforms via a splicing of the primary transcript ( neflbE4 and neflbE3 ). In vivo imaging showed that neflb is crucial for proper neuronal development, and that disrupting the balance between its two isoforms specifically affects the NF assembly and motor axon growth, with resultant motor deficits. This equilibrium is also disrupted upon the partial depletion of TDP-43 (TAR DNA-binding protein 43), an RNA-binding protein encoded by the gene TARDBP that is mislocalized into cytoplasmic inclusions in ALS. The study supports the interaction of the NEFL expression and splicing with TDP-43 in a common pathway, both biologically and pathogenetically.
- Published
- 2020
- Full Text
- View/download PDF