Format

Send to

Choose Destination
J Clin Invest. 2011 Feb;121(2):726-38. doi: 10.1172/JCI44867. Epub 2011 Jan 4.

Dysregulation of the ALS-associated gene TDP-43 leads to neuronal death and degeneration in mice.

Author information

1
Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, and Institute on Aging, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.

Abstract

Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are characterized by cytoplasmic protein aggregates in the brain and spinal cord that include TAR-DNA binding protein 43 (TDP-43). TDP-43 is normally localized in the nucleus with roles in the regulation of gene expression, and pathological cytoplasmic aggregates are associated with depletion of nuclear protein. Here, we generated transgenic mice expressing human TDP-43 with a defective nuclear localization signal in the forebrain (hTDP-43-ΔNLS), and compared them with mice expressing WT hTDP-43 (hTDP-43-WT) to determine the effects of mislocalized cytoplasmic TDP-43 on neuronal viability. Expression of either hTDP-43-ΔNLS or hTDP-43-WT led to neuron loss in selectively vulnerable forebrain regions, corticospinal tract degeneration, and motor spasticity recapitulating key aspects of FTLD and primary lateral sclerosis. Only rare cytoplasmic phosphorylated and ubiquitinated TDP-43 inclusions were seen in hTDP-43-ΔNLS mice, suggesting that cytoplasmic inclusions were not required to induce neuronal death. Instead, neurodegeneration in hTDP-43 and hTDP-43-ΔNLS-expressing neurons was accompanied by a dramatic downregulation of the endogenous mouse TDP-43. Moreover, mice expressing hTDP-43-ΔNLS exhibited profound changes in gene expression in cortical neurons. Our data suggest that perturbation of endogenous nuclear TDP-43 results in loss of normal TDP-43 function(s) and gene regulatory pathways, culminating in degeneration of selectively vulnerable affected neurons.

PMID:
21206091
PMCID:
PMC3026736
DOI:
10.1172/JCI44867
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for American Society for Clinical Investigation Icon for PubMed Central
Loading ...
Support Center