Abstract

DEPDC5 mutations have recently been shown to cause epilepsy in humans. Evidence from in vitro studies has implicated DEPDC5 as a negative regulator of mTORC1 during amino acid insufficiency as part of the GATOR1 complex. To investigate the role of DEPDC5 in vivo we generated a null mouse model using targeted CRISPR mutagenesis. Depdc5 homozygotes display severe phenotypic defects between 12.5-15.5 dpc, including hypotrophy, anaemia, oedema, and cranial dysmorphology as well as blood and lymphatic vascular defects. mTORC1 hyperactivity was observed in the brain of knockout embryos and in fibroblasts and neurospheres isolated from knockout embryos and cultured in nutrient deprived conditions. Heterozygous mice appeared to be normal and we found no evidence of increased susceptibility to seizures or tumorigenesis. Together, these data support mTORC1 hyperactivation as the likely pathogenic mechanism that underpins DEPDC5 loss of function in humans and highlights the potential utility of mTORC1 inhibitors in the treatment of DEPDC5-associated epilepsy.

Details

Title
Knockout of the epilepsy gene Depdc5 in mice causes severe embryonic dysmorphology with hyperactivity of mTORC1 signalling
Author
Hughes, James 1 ; Dawson, Ruby 1 ; Tea, Melinda 2 ; McAninch, Dale 1 ; Piltz, Sandra 1 ; Jackson, Dominique 1 ; Stewart, Laura 1 ; Ricos, Michael G 3 ; Dibbens, Leanne M 3 ; Harvey, Natasha L 2 ; Thomas, Paul 1 

 School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia 
 Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, SA, Australia 
 University of South Australia, Epilepsy Research Program, School of Pharmacy and Medical Sciences, Adelaide, SA, Australia 
Pages
1-15
Publication year
2017
Publication date
Oct 2017
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
1957794985
Copyright
© 2017. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.