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

2017 ◽  
Vol 9 (391) ◽  
pp. eaaf3962 ◽  
Author(s):  
Keiko Imamura ◽  
Yuishin Izumi ◽  
Akira Watanabe ◽  
Kayoko Tsukita ◽  
Knut Woltjen ◽  
...  

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.

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 571 ◽  
Author(s):  
Emily R. Seminary ◽  
Stephanie Santarriaga ◽  
Lynn Wheeler ◽  
Marie Mejaki ◽  
Jenica Abrudan ◽  
...  

Amyotrophic lateral sclerosis (ALS) is a complex neurodegenerative disorder characterized by the loss of the upper and lower motor neurons. Approximately 10% of cases are caused by specific mutations in known genes, with the remaining cases having no known genetic link. As such, sporadic cases have been more difficult to model experimentally. Here, we describe the generation and differentiation of ALS induced pluripotent stem cells reprogrammed from discordant identical twins. Whole genome sequencing revealed no relevant mutations in known ALS-causing genes that differ between the twins. As protein aggregation is found in all ALS patients and is thought to contribute to motor neuron death, we sought to characterize the aggregation phenotype of the sporadic ALS induced pluripotent stem cells (iPSCs). Motor neurons from both twins had high levels of insoluble proteins that commonly aggregate in ALS that did not robustly change in response to exogenous glutamate. In contrast, established genetic ALS iPSC lines demonstrated insolubility in a protein- and genotype-dependent manner. Moreover, whereas the genetic ALS lines failed to induce autophagy after glutamate stress, motor neurons from both twins and independent controls did activate this protective pathway. Together, these data indicate that our unique model of sporadic ALS may provide key insights into disease pathology and highlight potential differences between sporadic and familial ALS.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Yoshiaki Furukawa

Dominant mutations in a Cu, Zn-superoxide dismutase (SOD1) gene cause a familial form of amyotrophic lateral sclerosis (ALS). While it remains controversial how SOD1 mutations lead to onset and progression of the disease, manyin vitroandin vivostudies have supported a gain-of-toxicity mechanism where pathogenic mutations contribute to destabilizing a native structure of SOD1 and thus facilitate misfolding and aggregation. Indeed, abnormal accumulation of SOD1-positive inclusions in spinal motor neurons is a pathological hallmark in SOD1-related familial ALS. Furthermore, similarities in clinical phenotypes and neuropathology of ALS cases with and without mutations insod1gene have implied a disease mechanism involving SOD1 common to all ALS cases. Although pathogenic roles of wild-type SOD1 in sporadic ALS remain controversial, recent developments of novel SOD1 antibodies have made it possible to characterize wild-type SOD1 under pathological conditions of ALS. Here, I have briefly reviewed recent progress on biochemical and immunohistochemical characterization of wild-type SOD1 in sporadic ALS cases and discussed possible involvement of wild-type SOD1 in a pathomechanism of ALS.


Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2773
Author(s):  
Hsiao-Chien Ting ◽  
Hui-I Yang ◽  
Horng-Jyh Harn ◽  
Ing-Ming Chiu ◽  
Hong-Lin Su ◽  
...  

Amyotrophic lateral sclerosis (ALS) is a progressive nervous system disease that causes motor neuron (MN) degeneration and results in patient death within a few years. To recapitulate the cytopathies of ALS patients’ MNs, SOD1G85R mutant and corrected SOD1G85G isogenic-induced pluripotent stem cell (iPSC) lines were established. Two SOD1 mutant ALS (SOD1G85R and SOD1D90A), two SOD1 mutant corrected (SOD1G85G and SOD1D90D), and one sporadic ALS iPSC lines were directed toward MNs. After receiving ~90% purity for MNs, we first demonstrated that SOD1G85R mutant ALS MNs recapitulated ALS-specific nerve fiber aggregates, similar to SOD1D90A ALS MNs in a previous study. Moreover, we found that both SOD1 mutant MNs showed ALS-specific neurite degenerations and neurotransmitter-induced calcium hyperresponsiveness. In a small compound test using these MNs, we demonstrated that gastrodin, a major ingredient of Gastrodia elata, showed therapeutic effects that decreased nerve fiber cytopathies and reverse neurotransmitter-induced hyperresponsiveness. The therapeutic effects of gastrodin applied not only to SOD1 ALS MNs but also to sporadic ALS MNs and SOD1G93A ALS mice. Moreover, we found that coactivation of the GSK3β and IGF-1 pathways was a mechanism involved in the therapeutic effects of gastrodin. Thus, the coordination of compounds that activate these two mechanisms could reduce nerve fiber cytopathies in SOD1 ALS MNs. Interestingly, the therapeutic role of GSK3β activation on SOD1 ALS MNs in the present study was in contrast to the role previously reported in research using cell line- or transgenic animal-based models. In conclusion, we identified in vitro ALS-specific nerve fiber and neurofunctional markers in MNs, which will be useful for drug screening, and we used an iPSC-based model to reveal novel therapeutic mechanisms (including GSK3β and IGF-1 activation) that may serve as potential targets for ALS therapy.


2020 ◽  
Vol 21 (8) ◽  
pp. 2943 ◽  
Author(s):  
Agata Grazia D’Amico ◽  
Grazia Maugeri ◽  
Salvatore Saccone ◽  
Concetta Federico ◽  
Sebastiano Cavallaro ◽  
...  

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease of complex etiology leading to motor neuron degeneration. Many gene alterations cause this pathology, including mutation in Cu, Zn superoxide dismutase (SOD1), which leads to its gain of function. Mutant SOD1 proteins are prone to aberrant misfolding and create aggregates that impair autophagy. The hypoxic stress is strictly linked to the disease progression since it induces uncontrolled autophagy activation and the consequent high rates of cell death. Previously, we showed that pituitary adenylate cyclase-activating polypeptide (PACAP) exerts neurotrophic activity in cultured mSOD1 motor neurons exposed to serum deprivation. To date, no studies have examined whether the protective effect of PACAP on mSOD1 cells exposed to hypoxic insult is mediated through the regulation of the autophagy process. In the present study, we used the neuroblastoma-spinal cord-34 (NSC-34) cell line, stably expressing human wild type or mutant SOD1 G93A, to represent a well characterized in vitro model of a familial form of ALS. These cells were exposed to 100-µM desferrioxamine mesylate salt for 24h, to mimic the hypoxic stress affecting motor neurons during the disease progression. Our results showed that PACAP treatment significantly reduced cell death and hypoxia-induced mSOD1 accumulation by modulating the autophagy process in G93A motor neurons, as revealed by the decreased LC3II and the increased p62 levels, two autophagy indicators. These results were also confirmed by evaluating the vacuole formation detected through light chain 3 (LC3) immunofluorescence. Furthermore, the PACAP effects on autophagy seem to be mediated through the activation of the MAPK/ERK signaling pathway. Overall, our data demonstrated that PACAP exerts an ameliorative effect on the mSOD1 motor neuron viability by modulating a hypoxia-induced autophagy process through activation of MAPK/ERK signaling cascade.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Jurate Lasiene ◽  
Koji Yamanaka

Amyotrophic lateral sclerosis (ALS) is an adult motor neuron disease characterized by premature death of upper and lower motor neurons. Two percent of ALS cases are caused by the dominant mutations in the gene for superoxide dismutase 1 (SOD1) through a gain of toxic property of mutant protein. Genetic and chimeric mice studies using SOD1 models indicate that non-neuronal cells play important roles in neurodegeneration through non-cell autonomous mechanism. We review the contribution of each glial cell type in ALS pathology from studies of the rodent models and ALS patients. Astrogliosis and microgliosis are not only considerable hallmarks of the disease, but the intensity of microglial activation is correlated with severity of motor neuron damage in human ALS. The impaired astrocytic functions such as clearance of extracellular glutamate and release of neurotrophic factors are implicated in disease. Further, the damage within astrocytes and microglia is involved in accelerated disease progression. Finally, other glial cells such as NG2 cells, oligodendrocytes and Schwann cells are under the investigation to determine their contribution in ALS. Accumulating knowledge of active role of glial cells in the disease should be carefully applied to understanding of the sporadic ALS and development of therapy targeted for glial cells.


2021 ◽  
Vol 22 (4) ◽  
pp. 1796
Author(s):  
Audrey Dangoumau ◽  
Sylviane Marouillat ◽  
Roxane Coelho ◽  
François Wurmser ◽  
Céline Brulard ◽  
...  

Protein aggregates in affected motor neurons are a hallmark of amyotrophic lateral sclerosis (ALS), but the molecular pathways leading to their formation remain incompletely understood. Oxidative stress associated with age, the major risk factor in ALS, contributes to this neurodegeneration in ALS. We show that several genes coding for enzymes of the ubiquitin and small ubiquitin-related modifier (SUMO) pathways exhibit altered expression in motor neuronal cells exposed to oxidative stress, such as the CCNF gene mutated in ALS patients. Eleven of these genes were further studied in conditions combining oxidative stress and the expression of an ALS related mutant of the superoxide dismutase 1 (SOD1) gene. We observed a combined effect of these two environmental and genetic factors on the expression of genes, such as Uhrf2, Rbx1, Kdm2b, Ube2d2, Xaf1, and Senp1. Overall, we identified dysregulations in the expression of enzymes of the ubiquitin and SUMO pathways that may be of interest to better understand the pathophysiology of ALS and to protect motor neurons from oxidative stress and genetic alterations.


2022 ◽  
Author(s):  
Reilly L Allison ◽  
Jacob W Adelman ◽  
Jenica Abrudan ◽  
Raul A Urrutia ◽  
Michael T Zimmermann ◽  
...  

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease in which upper and lower motor neuron loss is the primary phenotype, leading to muscle weakness and wasting, respiratory failure, and death. Although a portion of ALS cases are linked to one of over 50 unique genes, the vast majority of cases are sporadic in nature. However, the mechanisms underlying the motor neuron loss in either familial or sporadic ALS are not entirely clear. Here we used induced pluripotent stem cells derived from a set of identical twin brothers discordant for ALS to assess the role of astrocytes and microglia on the expression and accumulation of neurofilament proteins in motor neurons. We found that motor neurons derived from the affected twin exhibited increased transcript levels of all three neurofilament isoforms and increased expression of phosphorylated neurofilament puncta. We further found that treatment of the motor neurons with astrocyte conditioned medium and microglial conditioned medium significantly impacted neurofilament deposition. Together, these data suggest that glial-secreted factors can alter neurofilament pathology in ALS iPSC-derived motor neurons.


Brain ◽  
2020 ◽  
Vol 143 (2) ◽  
pp. 430-440 ◽  
Author(s):  
Phillip Smethurst ◽  
Emmanuel Risse ◽  
Giulia E Tyzack ◽  
Jamie S Mitchell ◽  
Doaa M Taha ◽  
...  

Abstract Amyotrophic lateral sclerosis (ALS) is a fatal and incurable neurodegenerative disease caused by motor neuron loss, resulting in muscle wasting, paralysis and eventual death. A key pathological feature of ALS is cytoplasmically mislocalized and aggregated TDP-43 protein in >95% of cases, which is considered to have prion-like properties. Historical studies have predominantly focused on genetic forms of ALS, which represent ∼10% of cases, leaving the remaining 90% of sporadic ALS relatively understudied. Additionally, the role of astrocytes in ALS and their relationship with TDP-43 pathology is also not currently well understood. We have therefore used highly enriched human induced pluripotent stem cell (iPSC)-derived motor neurons and astrocytes to model early cell type-specific features of sporadic ALS. We first demonstrate seeded aggregation of TDP-43 by exposing human iPSC-derived motor neurons to serially passaged sporadic ALS post-mortem tissue (spALS) extracts. Next, we show that human iPSC-derived motor neurons are more vulnerable to TDP-43 aggregation and toxicity compared with their astrocyte counterparts. We demonstrate that these TDP-43 aggregates can more readily propagate from motor neurons into astrocytes in co-culture paradigms. We next found that astrocytes are neuroprotective to seeded aggregation within motor neurons by reducing (mislocalized) cytoplasmic TDP-43, TDP-43 aggregation and cell toxicity. Furthermore, we detected TDP-43 oligomers in these spALS spinal cord extracts, and as such demonstrated that highly purified recombinant TDP-43 oligomers can reproduce this observed cell-type specific toxicity, providing further support to a protein oligomer-mediated toxicity hypothesis in ALS. In summary, we have developed a human, clinically relevant, and cell-type specific modelling platform that recapitulates key aspects of sporadic ALS and uncovers both an initial neuroprotective role for astrocytes and the cell type-specific toxic effect of TDP-43 oligomers.


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