C9orf72 and RAB7L1 regulate vesicle trafficking in amyotrophic lateral sclerosis and frontotemporal dementia.
A non-coding hexanucleotide repeat expansion in intron 1 of the C9orf72 gene is the most common cause of amyotrophic lateral sclerosis and frontotemporal dementia (C9ALS/FTD), however, the precise molecular mechanism by which the C9orf72 hexanucleotide repeat expansion directs C9ALS/FTD pathogenesis remains unclear. Here, we report a novel disease mechanism arising due to the interaction of C9ORF72 with the RAB7L1 GTPase to regulate vesicle trafficking. Endogenous interaction between C9ORF72 and RAB7L1 was confirmed in human SH-SY5Y neuroblastoma cells. The C9orf72 hexanucleotide repeat expansion led to haploinsufficiency resulting in severely defective intracellular and extracellular vesicle trafficking and a dysfunctional trans-Golgi network phenotype in patient-derived fibroblasts and induced pluripotent stem cell-derived motor neurons. Genetic ablation of RAB7L1or C9orf72 in SH-SY5Y cells recapitulated the findings in C9ALS/FTD fibroblasts and induced pluripotent stem cell neurons. When C9ORF72 was overexpressed or antisense oligonucleotides were targeted to the C9orf72 hexanucleotide repeat expansion to upregulate normal variant 1 transcript levels, the defective vesicle trafficking and dysfunctional trans-Golgi network phenotypes were reversed, suggesting that both loss- and gain-of-function mechanisms play a role in disease pathogenesis. In conclusion, we have identified a novel mechanism for C9ALS/FTD pathogenesis highlighting the molecular regulation of intracellular and extracellular vesicle trafficking as an important pathway in C9ALS/FTD pathogenesis.
Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK.|Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo, 187-8502, Japan.
Yoshitsugu
Y
Aoki
Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK.
Raquel
R
Manzano
Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK.
Yi
Y
Lee
Nuffield Department of Clinical Neurosciences, University of Oxford, Level 6, West Wing, John Radcliffe Hospital, Oxford OX3 9DU, UK.
Ruxandra
R
Dafinca
Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK.
Misako
M
Aoki
Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK.
Andrew G L
AGL
Douglas
Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK.
Miguel A
MA
Varela
Nuffield Department of Clinical Neurosciences, University of Oxford, Level 6, West Wing, John Radcliffe Hospital, Oxford OX3 9DU, UK.
Chaitra
C
Sathyaprakash
Nuffield Department of Clinical Neurosciences, University of Oxford, Level 6, West Wing, John Radcliffe Hospital, Oxford OX3 9DU, UK.
Jakub
J
Scaber
Nuffield Department of Clinical Neurosciences, University of Oxford, Level 6, West Wing, John Radcliffe Hospital, Oxford OX3 9DU, UK.
Paola
P
Barbagallo
Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK.|Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands.
Pieter
P
Vader
Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK.
Imre
I
Mäger
Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK.|Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden.
Kariem
K
Ezzat
Nuffield Department of Clinical Neurosciences, University of Oxford, Level 6, West Wing, John Radcliffe Hospital, Oxford OX3 9DU, UK.
Martin R
MR
Turner
Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo, 187-8502, Japan.
Naoki
N
Ito
Lagenbio, Veterinary Faculty of Zaragoza, Instituto Agroalimentario de Aragon (I2A), Health Research Institute of Aragon (IIS), University of Zaragoza, Zaragoza, Spain.
Samanta
S
Gasco
Department of Physiological Chemistry, Faculty of Medicine and Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan.
Norihiko
N
Ohbayashi
Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK.|Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden.
Samir
S
El Andaloussi
Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo, 187-8502, Japan.
Shin'ichi
S
Takeda
Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan.
Mitsunori
M
Fukuda
Nuffield Department of Clinical Neurosciences, University of Oxford, Level 6, West Wing, John Radcliffe Hospital, Oxford OX3 9DU, UK.
Kevin
K
Talbot
Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK.
Matthew J A
MJA
Wood
D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D001692:Biological Transport; D000073885:C9orf72 Protein; D019556:COS Cells; D002460:Cell Line; D002522:Chlorocebus aethiops; D042622:DNA Repeat Expansion; D005347:Fibroblasts / Q000187:drug effects / Q000473:pathology; D057180:Frontotemporal Dementia / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007438:Introns; D009046:Motor Neurons / Q000187:drug effects / Q000473:pathology; D009474:Neurons / Q000187:drug effects / Q000473:pathology; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D010375:Pedigree; D039904:Pluripotent Stem Cells / Q000187:drug effects / Q000473:pathology; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D020691:rab GTP-Binding Proteins; D020761:rab1 GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
D000073885:C9orf72 Protein; C568651:C9orf72 protein, human; D016376:Oligonucleotides, Antisense; D011506:Proteins; C000598762:Rab29 protein, human; D020691:rab GTP-Binding Proteins; D020761:rab1 GTP-Binding Proteins
C9ALS/FTD; C9orf72; RAB7L1; extracellular vesicles; haploinsufficiency