Limits...
Ethosuximide ameliorates neurodegenerative disease phenotypes by modulating DAF-16/FOXO target gene expression.

Chen X, McCue HV, Wong SQ, Kashyap SS, Kraemer BC, Barclay JW, Burgoyne RD, Morgan A - Mol Neurodegener (2015)

Bottom Line: Transcriptomic analysis revealed a highly significant up-regulation of DAF-16/FOXO target genes in response to ethosuximide; and indeed RNAi knockdown of daf-16 abolished the therapeutic effect of ethosuximide in the worm dnj-14 model.Importantly, ethosuximide also increased the expression of classical FOXO target genes and reduced protein aggregation in mammalian neuronal cells.We have revealed a conserved neuroprotective mechanism of action of ethosuximide from worms to mammalian neurons.

View Article: PubMed Central - PubMed

Affiliation: Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool, L69 3BX, UK. Xi.Chen@vai.org.

ABSTRACT

Background: Many neurodegenerative diseases are associated with protein misfolding/aggregation. Treatments mitigating the effects of such common pathological processes, rather than disease-specific symptoms, therefore have general therapeutic potential.

Results: Here we report that the anti-epileptic drug ethosuximide rescues the short lifespan and chemosensory defects exhibited by C. elegans mutants of dnj-14, the worm orthologue of the DNAJC5 gene mutated in autosomal-dominant adult-onset neuronal ceroid lipofuscinosis. It also ameliorates the locomotion impairment and short lifespan of worms expressing a human Tau mutant that causes frontotemporal dementia. Transcriptomic analysis revealed a highly significant up-regulation of DAF-16/FOXO target genes in response to ethosuximide; and indeed RNAi knockdown of daf-16 abolished the therapeutic effect of ethosuximide in the worm dnj-14 model. Importantly, ethosuximide also increased the expression of classical FOXO target genes and reduced protein aggregation in mammalian neuronal cells.

Conclusions: We have revealed a conserved neuroprotective mechanism of action of ethosuximide from worms to mammalian neurons. Future experiments in mouse neurodegeneration models will be important to confirm the repurposing potential of this well-established anti-epileptic drug for treatment of human neurodegenerative diseases.

No MeSH data available.


Related in: MedlinePlus

Ethosuximide increases lifespan and improves sensorimotor function in C. elegans ANCL and frontotemporal dementia models.a Ethosuximide extends lifespan in dnj-14 mutants. Viability of age-synchronised dnj-14(ok237) animals grown in the presence of the indicated concentrations of ethosuximide was determined; untreated wild type control N2 worms are shown for comparison (n = 50-55 worms for each concentration). b Ethosuximide ameliorates the dnj-14 food sensing defect. The time taken to move to a bacterial food source was measured in wild type N2 and dnj-14(tm3223) strains grown until 5-6 days of age in the presence or absence of ethosuximide (n = 71-80 worms of each strain per condition). c Ethosuximide increases locomotion in Tau V337M worms, but not control worms. Thrashing in solution was measured in Tau V337M worms grown until 1 and 3 days of age and assayed in the presence of the indicated concentrations of ethosuximide (for each age group, n = 120-140 worms for 0 mg/l; n = 38-40 worms for 0.1, 0.2 and 0.5 mg/ml; n = 80-90 worms for 1 and 2 mg/ml;). Identically treated wild type control CZ1200 worms are shown for comparison (n = 20 worms per concentration). Data are shown as mean ± SEM (***p < 0.001). d Age-dependence of ethosuximide’s effect on Tau V337M locomotion. Thrashing assays were performed on age-synchronised animals grown in the presence or absence of 2 mg/ml ethosuximide (n = 30-50 worms per data point). Data are shown as mean ± SEM (***p < 0.001, *p < 0.05). e Ethosuximide increases lifespan in Tau V337M worms. Viability of age-synchronised animals grown in the presence of the indicated concentrations of ethosuximide was determined in comparison to untreated wild type control CZ1200 worms (n = 50-102 worms for each drug concentration). f Comparison of the ethosuximide concentration-dependence of mean lifespan extension in dnj-14 and Tau V337M worms
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4587861&req=5

Fig1: Ethosuximide increases lifespan and improves sensorimotor function in C. elegans ANCL and frontotemporal dementia models.a Ethosuximide extends lifespan in dnj-14 mutants. Viability of age-synchronised dnj-14(ok237) animals grown in the presence of the indicated concentrations of ethosuximide was determined; untreated wild type control N2 worms are shown for comparison (n = 50-55 worms for each concentration). b Ethosuximide ameliorates the dnj-14 food sensing defect. The time taken to move to a bacterial food source was measured in wild type N2 and dnj-14(tm3223) strains grown until 5-6 days of age in the presence or absence of ethosuximide (n = 71-80 worms of each strain per condition). c Ethosuximide increases locomotion in Tau V337M worms, but not control worms. Thrashing in solution was measured in Tau V337M worms grown until 1 and 3 days of age and assayed in the presence of the indicated concentrations of ethosuximide (for each age group, n = 120-140 worms for 0 mg/l; n = 38-40 worms for 0.1, 0.2 and 0.5 mg/ml; n = 80-90 worms for 1 and 2 mg/ml;). Identically treated wild type control CZ1200 worms are shown for comparison (n = 20 worms per concentration). Data are shown as mean ± SEM (***p < 0.001). d Age-dependence of ethosuximide’s effect on Tau V337M locomotion. Thrashing assays were performed on age-synchronised animals grown in the presence or absence of 2 mg/ml ethosuximide (n = 30-50 worms per data point). Data are shown as mean ± SEM (***p < 0.001, *p < 0.05). e Ethosuximide increases lifespan in Tau V337M worms. Viability of age-synchronised animals grown in the presence of the indicated concentrations of ethosuximide was determined in comparison to untreated wild type control CZ1200 worms (n = 50-102 worms for each drug concentration). f Comparison of the ethosuximide concentration-dependence of mean lifespan extension in dnj-14 and Tau V337M worms

Mentions: The rare hereditary human neurodegenerative disease, autosomal-dominant adult-onset neuronal ceroid lipofuscinosis (ANCL), is caused by mutations in the DNAJC5 gene [19–22]. DNAJC5 encodes a neuronal chaperone of the DnaJ/Hsp40 family of molecular chaperones known as cysteine string protein (CSP), which prevents the misfolding of presynaptic proteins [23–27]. DNJ-14 is the worm orthologue of CSP and dnj-14 mutants are characterised by reduced lifespan and age-dependent sensorimotor defects and neurodegeneration, similar to CSP knockout mice [18, 28]. We used this dnj-14 model to screen for compounds with therapeutic potential for ANCL and possibly other neurodegenerative diseases, by testing their ability to extend the short lifespan of dnj-14(ok237) worms [18]. The anti-epileptic drug, ethosuximide, was observed to produce a robust and reproducible lifespan extension in dnj-14(ok237) animals. This effect was concentration-dependent, with 1 mg/ml ethosuximide offering the most significant lifespan increase, raising the mean lifespan of dnj-14(ok237) worms by over 40 % (Fig. 1a) Over a series of experiments, this optimal concentration produced a near-complete rescue of lifespan in dnj-14 mutants to levels close to that of wild-type N2 worms (Additional file 1: Table S1). At the highest concentration used (4 mg/ml), ethosuximide produced no significant increase in lifespan. Notably, none of the concentrations used had any significant effect on the lifespan of wild-type N2 C. elegans (Additional file 2: Figure S1A; Additional file 1: Table S1). To test if ethosuximide was also able to rescue the sensory defect in dnj-14 mutants, we performed a food race assay, which measures the time taken for animals to move a defined distance to a bacterial food source (Fig. 1b). As previously observed [18], dnj-14 mutants are severely impaired in this assay. Ethosuximide significantly improved food sensing activity of dnj-14 mutants, approximately doubling the number of worms reaching the food within 60 min, although complete rescue to wild type levels was not achieved (Fig. 1b). Ethosuximide had no stimulatory activity in food race assays using wild type N2 worms (Fig. 1b), nor did it increase locomotion of dnj-14 or N2 worms in thrashing assays (Additional file 2: Figure S1B). Therefore the stimulatory action of ethosuximide in food race assays appears to be due to a specific effect on the chemosensory defect in dnj-14 mutants rather than a generic stimulation of movement. Taken together, these data suggest that ethosuximide is able to ameliorate the neurotoxicity induced by the loss of the DNJ-14 synaptic chaperone protein.Fig. 1


Ethosuximide ameliorates neurodegenerative disease phenotypes by modulating DAF-16/FOXO target gene expression.

Chen X, McCue HV, Wong SQ, Kashyap SS, Kraemer BC, Barclay JW, Burgoyne RD, Morgan A - Mol Neurodegener (2015)

Ethosuximide increases lifespan and improves sensorimotor function in C. elegans ANCL and frontotemporal dementia models.a Ethosuximide extends lifespan in dnj-14 mutants. Viability of age-synchronised dnj-14(ok237) animals grown in the presence of the indicated concentrations of ethosuximide was determined; untreated wild type control N2 worms are shown for comparison (n = 50-55 worms for each concentration). b Ethosuximide ameliorates the dnj-14 food sensing defect. The time taken to move to a bacterial food source was measured in wild type N2 and dnj-14(tm3223) strains grown until 5-6 days of age in the presence or absence of ethosuximide (n = 71-80 worms of each strain per condition). c Ethosuximide increases locomotion in Tau V337M worms, but not control worms. Thrashing in solution was measured in Tau V337M worms grown until 1 and 3 days of age and assayed in the presence of the indicated concentrations of ethosuximide (for each age group, n = 120-140 worms for 0 mg/l; n = 38-40 worms for 0.1, 0.2 and 0.5 mg/ml; n = 80-90 worms for 1 and 2 mg/ml;). Identically treated wild type control CZ1200 worms are shown for comparison (n = 20 worms per concentration). Data are shown as mean ± SEM (***p < 0.001). d Age-dependence of ethosuximide’s effect on Tau V337M locomotion. Thrashing assays were performed on age-synchronised animals grown in the presence or absence of 2 mg/ml ethosuximide (n = 30-50 worms per data point). Data are shown as mean ± SEM (***p < 0.001, *p < 0.05). e Ethosuximide increases lifespan in Tau V337M worms. Viability of age-synchronised animals grown in the presence of the indicated concentrations of ethosuximide was determined in comparison to untreated wild type control CZ1200 worms (n = 50-102 worms for each drug concentration). f Comparison of the ethosuximide concentration-dependence of mean lifespan extension in dnj-14 and Tau V337M worms
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4587861&req=5

Fig1: Ethosuximide increases lifespan and improves sensorimotor function in C. elegans ANCL and frontotemporal dementia models.a Ethosuximide extends lifespan in dnj-14 mutants. Viability of age-synchronised dnj-14(ok237) animals grown in the presence of the indicated concentrations of ethosuximide was determined; untreated wild type control N2 worms are shown for comparison (n = 50-55 worms for each concentration). b Ethosuximide ameliorates the dnj-14 food sensing defect. The time taken to move to a bacterial food source was measured in wild type N2 and dnj-14(tm3223) strains grown until 5-6 days of age in the presence or absence of ethosuximide (n = 71-80 worms of each strain per condition). c Ethosuximide increases locomotion in Tau V337M worms, but not control worms. Thrashing in solution was measured in Tau V337M worms grown until 1 and 3 days of age and assayed in the presence of the indicated concentrations of ethosuximide (for each age group, n = 120-140 worms for 0 mg/l; n = 38-40 worms for 0.1, 0.2 and 0.5 mg/ml; n = 80-90 worms for 1 and 2 mg/ml;). Identically treated wild type control CZ1200 worms are shown for comparison (n = 20 worms per concentration). Data are shown as mean ± SEM (***p < 0.001). d Age-dependence of ethosuximide’s effect on Tau V337M locomotion. Thrashing assays were performed on age-synchronised animals grown in the presence or absence of 2 mg/ml ethosuximide (n = 30-50 worms per data point). Data are shown as mean ± SEM (***p < 0.001, *p < 0.05). e Ethosuximide increases lifespan in Tau V337M worms. Viability of age-synchronised animals grown in the presence of the indicated concentrations of ethosuximide was determined in comparison to untreated wild type control CZ1200 worms (n = 50-102 worms for each drug concentration). f Comparison of the ethosuximide concentration-dependence of mean lifespan extension in dnj-14 and Tau V337M worms
Mentions: The rare hereditary human neurodegenerative disease, autosomal-dominant adult-onset neuronal ceroid lipofuscinosis (ANCL), is caused by mutations in the DNAJC5 gene [19–22]. DNAJC5 encodes a neuronal chaperone of the DnaJ/Hsp40 family of molecular chaperones known as cysteine string protein (CSP), which prevents the misfolding of presynaptic proteins [23–27]. DNJ-14 is the worm orthologue of CSP and dnj-14 mutants are characterised by reduced lifespan and age-dependent sensorimotor defects and neurodegeneration, similar to CSP knockout mice [18, 28]. We used this dnj-14 model to screen for compounds with therapeutic potential for ANCL and possibly other neurodegenerative diseases, by testing their ability to extend the short lifespan of dnj-14(ok237) worms [18]. The anti-epileptic drug, ethosuximide, was observed to produce a robust and reproducible lifespan extension in dnj-14(ok237) animals. This effect was concentration-dependent, with 1 mg/ml ethosuximide offering the most significant lifespan increase, raising the mean lifespan of dnj-14(ok237) worms by over 40 % (Fig. 1a) Over a series of experiments, this optimal concentration produced a near-complete rescue of lifespan in dnj-14 mutants to levels close to that of wild-type N2 worms (Additional file 1: Table S1). At the highest concentration used (4 mg/ml), ethosuximide produced no significant increase in lifespan. Notably, none of the concentrations used had any significant effect on the lifespan of wild-type N2 C. elegans (Additional file 2: Figure S1A; Additional file 1: Table S1). To test if ethosuximide was also able to rescue the sensory defect in dnj-14 mutants, we performed a food race assay, which measures the time taken for animals to move a defined distance to a bacterial food source (Fig. 1b). As previously observed [18], dnj-14 mutants are severely impaired in this assay. Ethosuximide significantly improved food sensing activity of dnj-14 mutants, approximately doubling the number of worms reaching the food within 60 min, although complete rescue to wild type levels was not achieved (Fig. 1b). Ethosuximide had no stimulatory activity in food race assays using wild type N2 worms (Fig. 1b), nor did it increase locomotion of dnj-14 or N2 worms in thrashing assays (Additional file 2: Figure S1B). Therefore the stimulatory action of ethosuximide in food race assays appears to be due to a specific effect on the chemosensory defect in dnj-14 mutants rather than a generic stimulation of movement. Taken together, these data suggest that ethosuximide is able to ameliorate the neurotoxicity induced by the loss of the DNJ-14 synaptic chaperone protein.Fig. 1

Bottom Line: Transcriptomic analysis revealed a highly significant up-regulation of DAF-16/FOXO target genes in response to ethosuximide; and indeed RNAi knockdown of daf-16 abolished the therapeutic effect of ethosuximide in the worm dnj-14 model.Importantly, ethosuximide also increased the expression of classical FOXO target genes and reduced protein aggregation in mammalian neuronal cells.We have revealed a conserved neuroprotective mechanism of action of ethosuximide from worms to mammalian neurons.

View Article: PubMed Central - PubMed

Affiliation: Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool, L69 3BX, UK. Xi.Chen@vai.org.

ABSTRACT

Background: Many neurodegenerative diseases are associated with protein misfolding/aggregation. Treatments mitigating the effects of such common pathological processes, rather than disease-specific symptoms, therefore have general therapeutic potential.

Results: Here we report that the anti-epileptic drug ethosuximide rescues the short lifespan and chemosensory defects exhibited by C. elegans mutants of dnj-14, the worm orthologue of the DNAJC5 gene mutated in autosomal-dominant adult-onset neuronal ceroid lipofuscinosis. It also ameliorates the locomotion impairment and short lifespan of worms expressing a human Tau mutant that causes frontotemporal dementia. Transcriptomic analysis revealed a highly significant up-regulation of DAF-16/FOXO target genes in response to ethosuximide; and indeed RNAi knockdown of daf-16 abolished the therapeutic effect of ethosuximide in the worm dnj-14 model. Importantly, ethosuximide also increased the expression of classical FOXO target genes and reduced protein aggregation in mammalian neuronal cells.

Conclusions: We have revealed a conserved neuroprotective mechanism of action of ethosuximide from worms to mammalian neurons. Future experiments in mouse neurodegeneration models will be important to confirm the repurposing potential of this well-established anti-epileptic drug for treatment of human neurodegenerative diseases.

No MeSH data available.


Related in: MedlinePlus