PUBLICATION

Neuromuscular junction abnormalities in a zebrafish loss-of-function model of TDP-43

Authors

Bose, P., Armstrong, G.A.B., Drapeau, P.

ID

ZDB-PUB-181127-39

Date

2018

Source

Journal of neurophysiology 121(1): 285-297 (Journal)

Registered Authors

Armstrong, Gary A.B., Drapeau, Pierre

Keywords

ALS, Neuromuscular junction, Synaptic defects, TDP-43, zebrafish

MeSH Terms

Animals, Genetically Modified
Animals
Calcium Channels, L-Type/metabolism
3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology
TDP-43 Proteinopathies/drug therapy
TDP-43 Proteinopathies/metabolism
TDP-43 Proteinopathies/pathology
Zebrafish Proteins/genetics*
Zebrafish Proteins/metabolism*
Zebrafish
Motor Activity/drug effects
Motor Activity/physiology
Calcium Channel Agonists/pharmacology
Disease Models, Animal
CRISPR-Cas Systems
Loss of Function Mutation*
Neuromuscular Junction/drug effects
Neuromuscular Junction/growth & development
Neuromuscular Junction/metabolism*
Neuromuscular Junction/pathology*
Genotype
Synaptic Transmission/drug effects
Synaptic Transmission/physiology
DNA-Binding Proteins/genetics*
DNA-Binding Proteins/metabolism*
Alleles

(all 26)

PubMed

30461368 Full text @ J. Neurophysiol.

Abstract

Almost 90% of ALS cases are characterized by the presence of aggregates of insoluble, misfolded cytoplasmic TAR DNA binding protein of 43 kDa (TDP-43). Distal axonopathy with impaired neuromuscular junctions (NMJs) prior to motor neuron degeneration or clinical onset of symptoms has been hypothesized as an early pathology in ALS. However, synaptic defects at the NMJ caused by TDP-43 mutations have not been characterized. In this study, we examined a previously reported zebrafish line expressing the tardbp^Y220X/Y220X variant, which results in an unstable and degraded protein. These tardbp^-/- larvae, however, mature normally due to the upregulated expression of an alternative splice variant of the tardbp paralog tardbp-like, or tardbpl. We generated a mutant line with a CRISPR/Cas9-mediated 5 base pair deletion encompassing the ATG start codon of tardbpl and in-crossed these with tardbp^-/- mutants to obtain tardbp^-/- and tardbpl^-/- double mutants herein, referred to as hom/hom. We subsequently characterized morphological, coiling, locomotor, synaptic and NMJ structural abnormalities in the hom/hom mutants and in their genotypic controls. We observed that hom/hom mutants displayed gross morphological defects, early lethality, reduced locomotor function, aberrant quantal transmission and perturbed synapse architecture at the NMJ. We further employed pharmacological manipulations in an effort to rescue phenotypic defects and observed that tardbp^+/-; tardbpl^-/- (herein referred to as het/hom) mutants, but not hom/hom mutants, were sensitive to chronic treatments of Bay K 8644, an L-type calcium channel agonist. This result highlights the importance of partial vs complete loss of allelic functions of TDP-43.

Genes / Markers

Figures

Show all Figures

Expression

Phenotype

Fish	Conditions	Stage	Phenotype	Figure
WT	chemical treatment by environment: Bay-K-8644	Long-pec	fast muscle cell mini excitatory postsynaptic potential frequency, normal	Fig. 6
WT	chemical treatment by environment: Bay-K-8644	Long-pec	fast muscle cell neuromuscular synaptic transmission process quality, normal	Fig. 6
WT	chemical treatment by environment: Bay-K-8644	Long-pec	swimming occurrence, normal	Fig. 6
tardbpa^{udm104/udm104}	standard conditions	14-19 somites	musculoskeletal movement occurrence, normal	Fig. 3
tardbpa^{udm104/udm104}	standard conditions	Long-pec	eye size, normal	Fig. 2
tardbpa^{udm104/udm104}	standard conditions	Long-pec	fast muscle cell mini excitatory postsynaptic potential frequency, normal	Fig. 4
tardbpa^{udm104/udm104}	standard conditions	Long-pec	fast muscle cell neuromuscular synaptic transmission process quality, normal	Fig. 4
tardbpa^{udm104/udm104}	standard conditions	Long-pec	heart morphology, normal	Fig. 2
tardbpa^{udm104/udm104}	standard conditions	Long-pec	myotome neuromuscular junction development decreased occurrence, abnormal	Fig. 5
tardbpa^{udm104/udm104}	standard conditions	Long-pec	swimming occurrence, normal	Fig. 3

1 - 10 of 47

Show

Mutations / Transgenics

Allele	Construct	Type	Affected Genomic Region
fh301		Point Mutation	tardbpb
udm104		Small Deletion	tardbpa

Human Disease / Model

Human Disease	Fish	Conditions	Evidence
amyotrophic lateral sclerosis type 10	tardbpb^fh301/fh301; tardbpa^{udm104/udm104}	standard conditions	TAS
amyotrophic lateral sclerosis type 10	tardbpb^fh301/+; tardbpa^{udm104/udm104}	standard conditions	TAS

1 - 2 of 2

Show

Sequence Targeting Reagents

Target	Reagent	Reagent Type
tardbpa	CRISPR2-tardbpa	CRISPR

Fish

Fish
tardbpa^{udm104/udm104}
tardbpb^fh301/fh301
tardbpb^fh301/fh301; tardbpa^{udm104/udm104}
tardbpb^fh301/+; tardbpa^{udm104/udm104}
WT

Antibodies

Orthology

Engineered Foreign Genes

Mapping

Bose et al., 2018 ZDB-PUB-181127-39 PMID:30461368

Neuromuscular junction abnormalities in a zebrafish loss-of-function model of TDP-43

Bose et al., 2018

ZDB-PUB-181127-39
PMID:30461368