Inhibition of transglutaminase 2 mitigates transcriptional dysregulation in models of Huntington disease

Caused by a polyglutamine expansion in the huntingtin protein, Huntington's disease leads to striatal degeneration via the transcriptional dysregulation of a number of genes, including those involved in mitochondrial biogenesis. Here we show that transglutaminase 2, which is upregulated in HD,...

Full description

Saved in:
Bibliographic Details
Main Author: Sleiman, Sama F. (author)
Other Authors: Mashishi, Lata (author), Coppola, Giovanni (author), Thompson, Leslie M. (author), Ratan, Rajiv R. (author), Starkov, Anatoly (author), Antonyak, Marc A. (author)
Format: article
Published: 2010
Online Access:http://hdl.handle.net/10725/6142
http://dx.doi.org/10.1002/emmm.201000084
http://libraries.lau.edu.lb/research/laur/terms-of-use/articles.php
http://embomolmed.embopress.org/content/2/9/349.short
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Caused by a polyglutamine expansion in the huntingtin protein, Huntington's disease leads to striatal degeneration via the transcriptional dysregulation of a number of genes, including those involved in mitochondrial biogenesis. Here we show that transglutaminase 2, which is upregulated in HD, exacerbates transcriptional dysregulation by acting as a selective corepressor of nuclear genes; transglutaminase 2 interacts directly with histone H3 in the nucleus. In a cellular model of HD, transglutaminase inhibition de‐repressed two established regulators of mitochondrial function, PGC‐1α and cytochrome c and reversed susceptibility of human HD cells to the mitochondrial toxin, 3‐nitroproprionic acid; however, protection mediated by transglutaminase inhibition was not associated with improved mitochondrial bioenergetics. A gene microarray analysis indicated that transglutaminase inhibition normalized expression of not only mitochondrial genes but also 40% of genes that are dysregulated in HD striatal neurons, including chaperone and histone genes. Moreover, transglutaminase inhibition attenuated degeneration in a Drosophila model of HD and protected mouse HD striatal neurons from excitotoxicity. Altogether these findings demonstrate that selective TG inhibition broadly corrects transcriptional dysregulation in HD and defines a novel HDAC‐independent epigenetic strategy for treating neurodegeneration