The Src/c-Abl pathway is a potential therapeutic target in amyotrophic lateral sclerosis.

TLDR: Analysis of ALS patient iPSC-derived motor neurons indicates that Src/c-Abl inhibitors may have potential for treating ALS, and a phenotypic screen to repurpose existing drugs using ALS motor neuron survival as readout shows that inhibitors of Src or c-ABL kinases promoted autophagy and rescued ALS motor neurons from degeneration.

Abstract: Amyotrophic lateral sclerosis (ALS), a fatal disease causing progressive loss of motor neurons, still has no effective treatment We developed a phenotypic screen to repurpose existing drugs using ALS motor neuron survival as readout Motor neurons were generated from induced pluripotent stem cells (iPSCs) derived from an ALS patient with a mutation in superoxide dismutase 1 (SOD1) Results of the screen showed that more than half of the hits targeted the Src/c-Abl signaling pathway Src/c-Abl inhibitors increased survival of ALS iPSC-derived motor neurons in vitro Knockdown of Src or c-Abl with small interfering RNAs (siRNAs) also rescued ALS motor neuron degeneration One of the hits, bosutinib, boosted autophagy, reduced the amount of misfolded mutant SOD1 protein, and attenuated altered expression of mitochondrial genes Bosutinib also increased survival in vitro of ALS iPSC-derived motor neurons from patients with sporadic ALS or other forms of familial ALS caused by mutations in TAR DNA binding protein (TDP-43) or repeat expansions in C9orf72 Furthermore, bosutinib treatment modestly extended survival of a mouse model of ALS with an SOD1 mutation, suggesting that Src/c-Abl may be a potentially useful target for developing new drugs to treat ALS

Figures

Fig. 3. Mechanistic analysis of neuroprotective effects of Src/c-Abl inhibitors on mutant SOD1 ALS MNs

Fig. 2. Phenotypic screening using ALS MNs and identification of therapeutic targets

Fig. 1. Generation of MNs using transcription factors and modeling ALS-MNs

Fig. 4. Effect of Src/c-Abl inhibitor on iPSC-derived MNs with different genotypes and on ALS model mice

Full text

Edinburgh Research Explorer
The Src/c-Abl pathway is a potential therapeutic target in
amyotrophic lateral sclerosis
Citation for published version:
Imamura, K, Izumi, Y, Watanabe, A, Tsukita, K, Woltjen, K, Yamamoto, T, Hotta, A, Kondo, T, Kitaoka, S,
Ohta, A, Tanaka, A, Watanabe, D, Morita, M, Takuma, H, Tamaoka, A, Kunath, T, Wray, S, Furuya, H, Era,
T, Makioka, K, Okamoto, K, Fujisawa, T, Nishitoh, H, Homma, K, Ichijo, H, Julien, J-P, Obata, N, Hosokawa,
M, Akiyama, H, Kaneko, S, Ayaki, T, Ito, H, Kaji, R, Takahashi, R, Yamanaka, S & Inoue, H 2017, 'The
Src/c-Abl pathway is a potential therapeutic target in amyotrophic lateral sclerosis', Science Translational
Medicine, vol. 9, no. 391. https://doi.org/10.1126/scitranslmed.aaf3962,
https://doi.org/10.1126/scitranslmed.aaf3962
Digital Object Identifier (DOI):
10.1126/scitranslmed.aaf3962
10.1126/scitranslmed.aaf3962
Link:
Link to publication record in Edinburgh Research Explorer
Document Version:
Peer reviewed version
Published In:
Science Translational Medicine
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Download date: 10. Aug. 2022

Imamura et al.
1
Title: iPSC-based drug repositioning identifies the Src/c-Abl pathway as a therapeutic
target for ALS motor neurons
Authors: Keiko Imamura
1
*, Yuishin Izumi
2
, Akira Watanabe
1
, Kayoko Tsukita
1
, Knut
Woltjen
1,3
, Takuya Yamamoto
1,4
, Akitsu Hotta
1,4,5
, Takayuki Kondo
1
, Shiho Kitaoka
1
, Akira
Ohta
1
, Akito Tanaka
1
, Dai Watanabe
6
, Mitsuya Morita
7
, Hiroshi Takuma
8
, Akira Tamaoka
8
,
Tilo Kunath
9
, Selina Wray
10
, Hirokazu Furuya
11
, Takumi Era
12
, Kouki Makioka
13
, Koichi
Okamoto
14
, Takao Fujisawa
15
, Hideki Nishitoh
16
, Kengo Homma
15
, Hidenori Ichijo
15
, Jean-
Pierre Julien
17
, Nanako Obata
18
, Masato Hosokawa
18
, Haruhiko Akiyama
18
, Satoshi
Kaneko
19
, Takashi Ayaki
20
, Hidefumi Ito
21
, Ryuji Kaji
4
, Ryosuke Takahashi
20
, Shinya
Yamanaka
1,22
, Haruhisa Inoue
1†
Affiliations:
1 Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto 606-8507,
Japan
2 Department of Clinical Neuroscience, The University of Tokushima Graduate School,
Tokushima, 770-8503, Japan
3 Hakubi Center for Advanced Research, Kyoto University, Kyoto 606-8501, Japan
4 Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Kyoto
606-8507, Japan
5 PRESTO, JST, Saitama 332-0012, Japan
6 Department of Biological Sciences, Graduate School of Medicine, Kyoto University, Kyoto
606-8501, Japan

Imamura et al.
2
7 Division of Neurology, Department of Internal Medicine, Jichi Medical University,
Shimotsuke, 329-0498, Japan
8 Department of Neurology, Institute of Clinical Medicine, University of Tsukuba,
Tsukuba 305-8576, Japan
9 MRC Centre for Regenerative Medicine, School of Biological Sciences, University of
Edinburgh, 5 Little France Drive, Edinburgh, EH16 4UU
10 Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square,
London WC1N 3BG
11 Department of Neurology, Kochi Medical School, Kochi University, 783-8505, Japan
12 Department of Cell Modulation, Institute of Molecular Embryology and Genetics,
Kumamoto University, Kumamoto, 860-0811, Japan
13 Department of Neurology, Gunma University Graduate School of Medicine, Maebashi
371-8511, Japan
14 Geriatrics Research Institute and Hospital, Maebashi, 371-0847, Japan
15 Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo,
Bunkyo-ku, Tokyo 113-0033, Japan
16 Department of Medical Sciences, University of Miyazaki, 889-1601, Japan
17 Department of Psychiatry and Neurosciences, Research Centre of IUSMQ, Laval
University, Québec, Canada
18 Tokyo Metropolitan Institute of Medical Science 2-1-6 Kamikitazawa, Setagaya-ku,
Tokyo 156-8506, Japan
19 Department of Neurology, Kansai Medical University, Hirakata, 573-1191, Japan

Imamura et al.
3
20 Department of Neurology, Graduate School of Medicine, Kyoto University, Kyoto 606-
8507, Japan
21 Department of Neurology, Wakayama Medical University, Kimiidera, Wakayama 641-
8509, Japan
22 Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA
†
To whom correspondence should be addressed.
One sentence summary:
Patient iPSC-based models indicate Src/c-Abl inhibitors as anti-ALS therapeutics.

Imamura et al.
4
Abstract
Amyotrophic lateral sclerosis (ALS), a fatal motor neuron (MN) disease causing progressive
MN death, still has no effective therapeutics. Here we developed a phenotypic screen to
reposition existing drugs with a readout of MN survival using ALS patient induced
pluripotent stem cells (iPSCs) with mutations in Cu/Zn superoxide dismutase 1 (mutant
SOD1). Results of the screen showed that over half of the hit drugs were included in the
Src/c-Abl-associated signaling pathway. Src/c-Abl inhibitors increased the survival rate of
ALS MNs, and a knock-down approach rescued ALS MNs. One of these drugs improved
impaired autophagy, reduced misfolded SOD1 protein, and attenuated the energy shortage
with altered mitochondria-relevant gene expression as detected by single-cell transcriptome
analysis of ALS MNs. This drug was also effective for other genetic types of iPSC-derived
MNs including mutant TAR DNA-binding protein 43 kDa (TDP-43), C9orf72 repeat
expansion-associated familial ALS, and sporadic ALS. Furthermore, the Src/c-Abl inhibitor
extended the survival period of mutant SOD1-associated ALS model mice. Therefore, our
chemical-biology approach with iPSC-based drug repositioning could identify both
candidate drugs and a converged molecular pathway for ALS therapeutics.

Frequently asked questions

Q1. What are the contributions in this paper?

Imamura et al. this paper used mutant SOD1 transgenic mice to generate disease MNs with scale merit and simplicity for MN generation. 

Q2. What are the future works in this paper?

It may be important to examine other doses of bosutinib or other Src/c-Abl inhibitors, such as those showing efficient permeability of the blood-brain barrier, in future studies.