C9orf72 Hexanucleotide Expansions Are Associated with Altered Endoplasmic Reticulum Calcium Homeostasis and Stress Granule Formation in Induced Pluripotent Stem Cell-Derived Neurons from Patients with Amyotrophic Lateral Sclerosis and Frontotemporal Dementia.
An expanded hexanucleotide repeat in a noncoding region of the C9orf72 gene is a major cause of amyotrophic lateral sclerosis (ALS), accounting for up to 40% of familial cases and 7% of sporadic ALS in European populations. We have generated induced pluripotent stem cells (iPSCs) from fibroblasts of patients carrying C9orf72 hexanucleotide expansions, differentiated these to functional motor and cortical neurons, and performed an extensive phenotypic characterization. In C9orf72 iPSC-derived motor neurons, decreased cell survival is correlated with dysfunction in Ca(2+) homeostasis, reduced levels of the antiapoptotic protein Bcl-2, increased endoplasmic reticulum (ER) stress, and reduced mitochondrial membrane potential. Furthermore, C9orf72 motor neurons, and also cortical neurons, show evidence of abnormal protein aggregation and stress granule formation. This study is an extensive characterization of iPSC-derived motor neurons as cellular models of ALS carrying C9orf72 hexanucleotide repeats, which describes a novel pathogenic link between C9orf72 mutations, dysregulation of calcium signaling, and altered proteostasis and provides a potential pharmacological target for the treatment of ALS and the related neurodegenerative disease frontotemporal dementia. Stem Cells 2016;34:2063-2078.
Nuffield Department of Clinical Neurosciences.
Ruxandra
R
Dafinca
Nuffield Department of Clinical Neurosciences.
Jakub
J
Scaber
Nuffield Department of Clinical Neurosciences.
Nida'a
N
Ababneh
Nuffield Department of Clinical Neurosciences.
Tatjana
T
Lalic
Nuffield Department of Clinical Neurosciences.
Gregory
G
Weir
Department of Physiology, Anatomy and Genetics.
Helen
H
Christian
James Martin Stem Cell Facility, Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom.
Jane
J
Vowles
Department of Physiology, Anatomy and Genetics.
Andrew G L
AG
Douglas
Nuffield Department of Clinical Neurosciences.
Alexandra
A
Fletcher-Jones
James Martin Stem Cell Facility, Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom.
Cathy
C
Browne
Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan.
Mahito
M
Nakanishi
Nuffield Department of Clinical Neurosciences.
Martin R
MR
Turner
Department of Physiology, Anatomy and Genetics.
Richard
R
Wade-Martins
James Martin Stem Cell Facility, Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom.
Sally A
SA
Cowley
Nuffield Department of Clinical Neurosciences.
Kevin
K
Talbot
D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics / Q000473:pathology*; D017209:Apoptosis; D000073885:C9orf72 Protein / Q000235:genetics*; D002118:Calcium / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism; D002454:Cell Differentiation; D065150:Cellular Reprogramming; D002540:Cerebral Cortex / Q000473:pathology; D003594:Cytoplasmic Granules / Q000378:metabolism / Q000648:ultrastructure; D042622:DNA Repeat Expansion / Q000235:genetics*; D004721:Endoplasmic Reticulum / Q000378:metabolism* / Q000648:ultrastructure; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology; D057180:Frontotemporal Dementia / Q000235:genetics / Q000473:pathology*; D006706:Homeostasis / Q000235:genetics; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism / Q000648:ultrastructure; D009046:Motor Neurons / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism; D066329:Protein Aggregates; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D012313:RNA / Q000235:genetics
D000073885:C9orf72 Protein; C568651:C9orf72 protein, human; D010455:Peptides; D066329:Protein Aggregates; D019253:Proto-Oncogene Proteins c-bcl-2; D012313:RNA; D053148:Caspase 3; D002118:Calcium
Amyotrophic lateral sclerosis; C9orf72; Calcium dysregulation; Frontotemporal dementia; Induced pluripotent stem cells; Motor neurons