Conditional deletion of L1CAM in human neurons impairs both axonal and dendritic arborization and action potential generation
| Autor: | Marius Wernig, Claudio Acuna, Thomas C. Südhof, Louise R. Giam, Christopher Patzke |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
L1 Human Embryonic Stem Cells Immunology Mutant Cell Action Potentials Neural Cell Adhesion Molecule L1 Biology medicine.disease_cause Article 03 medical and health sciences 0302 clinical medicine medicine Humans Immunology and Allergy Ankyrin Research Articles Of Interest 030304 developmental biology chemistry.chemical_classification Genetics Mutation 0303 health sciences Dendrites From J. Exp. Med Cell Biology Axon initial segment Embryonic stem cell Axons Cell biology 030104 developmental biology medicine.anatomical_structure nervous system chemistry Gene Deletion Function (biology) Hydrocephalus 030215 immunology |
| Zdroj: | The Journal of Cell Biology The Journal of Experimental Medicine |
| ISSN: | 1540-8140 0021-9525 |
| DOI: | 10.1083/jcb.2127oia58 |
| Popis: | Patzke et al. create human embryonic stem cell–derived neurons that enable the generation of conditional loss-of-function mutations of L1CAM. Deletion of L1CAM impairs axonal elongation, dendritic arborization, and action potential generation. Hundreds of L1CAM gene mutations have been shown to be associated with congenital hydrocephalus, severe intellectual disability, aphasia, and motor symptoms. How such mutations impair neuronal function, however, remains unclear. Here, we generated human embryonic stem (ES) cells carrying a conditional L1CAM loss-of-function mutation and produced precisely matching control and L1CAM-deficient neurons from these ES cells. In analyzing two independent conditionally mutant ES cell clones, we found that deletion of L1CAM dramatically impaired axonal elongation and, to a lesser extent, dendritic arborization. Unexpectedly, we also detected an ∼20–50% and ∼20–30% decrease, respectively, in the levels of ankyrinG and ankyrinB protein, and observed that the size and intensity of ankyrinG staining in the axon initial segment was significantly reduced. Overexpression of wild-type L1CAM, but not of the L1CAM point mutants R1166X and S1224L, rescued the decrease in ankyrin levels. Importantly, we found that the L1CAM mutation selectively decreased activity-dependent Na+-currents, altered neuronal excitability, and caused impairments in action potential (AP) generation. Thus, our results suggest that the clinical presentations of L1CAM mutations in human patients could be accounted for, at least in part, by cell-autonomous changes in the functional development of neurons, such that neurons are unable to develop normal axons and dendrites and to generate normal APs. |
| Databáze: | OpenAIRE |
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