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Oral administration of PF-01247324, a subtype-selective Nav1.8 blocker, reverses cerebellar deficits in a mouse model of multiple sclerosis.

Shields SD, Butt RP, Dib-Hajj SD, Waxman SG - PLoS ONE (2015)

Bottom Line: Cerebellar symptoms significantly diminish quality of life in patients with multiple sclerosis (MS).PF-01247324 was administered by oral gavage at 1000 mg/kg; control groups received an equal volume of vehicle.These preclinical proof-of-concept data suggest that PF-01247324, its derivatives, or other Nav1.8-selective blockers merit further study for providing symptomatic therapy for cerebellar dysfunction in MS and related disorders.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut, United States of America; Rehabilitation Research Center, Veterans' Affairs Connecticut Healthcare System, West Haven, Connecticut, United States of America.

ABSTRACT
Cerebellar symptoms significantly diminish quality of life in patients with multiple sclerosis (MS). We previously showed that sodium channel Nav1.8, although normally restricted to peripheral somatosensory neurons, is upregulated in the cerebellum in MS, and that Nav1.8 expression is linked to ataxia and MS-like symptoms in mice. Furthermore, intracerebroventricular administration of the Nav1.8 blocker A-803467 temporarily reversed electrophysiological and behavioral manifestations of disease in a mouse MS model; unfortunately A-803467 is not orally bioavailable, diminishing the potential for translation to human patients. In the present study, we assessed the effect of per os (p.o.) dosing of a new orally bioavailable Nav1.8-selective blocker, PF-01247324, in transgenic mice expressing Nav1.8 in Purkinje neurons, and in wildtype mice in the experimental autoimmune encephalomyelitis (EAE) model. PF-01247324 was administered by oral gavage at 1000 mg/kg; control groups received an equal volume of vehicle. Behavioral assays of motor coordination, grip strength, and ataxia were performed. We observed significant improvements in motor coordination and cerebellar-like symptoms in mice that received PF-01247324 compared to control littermates that received vehicle. These preclinical proof-of-concept data suggest that PF-01247324, its derivatives, or other Nav1.8-selective blockers merit further study for providing symptomatic therapy for cerebellar dysfunction in MS and related disorders.

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Oral administration of PF-01247324 slightly improves MS-like deficits in the EAE model.EAE symptom progression was scored on a 0 to 6 scale [9], with 0.5-point gradations for intermediate scores, as follows: 0, normal; 1, flaccid tail; 2, impaired righting reflex or wobbly gait but no clear weakness; 3, weakness of both hindlimbs or paralysis of a single hindlimb; 4, complete hindlimb paralysis; 5, primarily recumbent and unable to ambulate; 6, death. A. C57Bl/6 mice with EAE that were administered vehicle had stable symptom scores over the 6 h observation period. (All timepoints p>0.05 compared to baseline (BL), paired t-tests. n = 19.) B. C57Bl/6 mice with EAE that were administered PF-01247324 showed a slight improvement in symptom scores after dosing, when analyzed with paired t-tests to compare individual timepoints to pre-drug BL. (1 h, p = 0.3299; 2 h, p = 0.5426; 3 h, p = 0.0493; 4 h, p = 0.0084; 5 h, p = 0.0555; 6 h, p = 0.6649; paired t-tests compared to BL. n = 20.) However, a two-way ANOVA did not show significant improvement compared to vehicle control. *, p<0.05 compared to BL, paired t-test.
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pone.0119067.g002: Oral administration of PF-01247324 slightly improves MS-like deficits in the EAE model.EAE symptom progression was scored on a 0 to 6 scale [9], with 0.5-point gradations for intermediate scores, as follows: 0, normal; 1, flaccid tail; 2, impaired righting reflex or wobbly gait but no clear weakness; 3, weakness of both hindlimbs or paralysis of a single hindlimb; 4, complete hindlimb paralysis; 5, primarily recumbent and unable to ambulate; 6, death. A. C57Bl/6 mice with EAE that were administered vehicle had stable symptom scores over the 6 h observation period. (All timepoints p>0.05 compared to baseline (BL), paired t-tests. n = 19.) B. C57Bl/6 mice with EAE that were administered PF-01247324 showed a slight improvement in symptom scores after dosing, when analyzed with paired t-tests to compare individual timepoints to pre-drug BL. (1 h, p = 0.3299; 2 h, p = 0.5426; 3 h, p = 0.0493; 4 h, p = 0.0084; 5 h, p = 0.0555; 6 h, p = 0.6649; paired t-tests compared to BL. n = 20.) However, a two-way ANOVA did not show significant improvement compared to vehicle control. *, p<0.05 compared to BL, paired t-test.

Mentions: Although L7–1.8TG mice can be seen as a simple model for one of the manifestations of MS, the EAE model is more realistic because it recapitulates more features of this complex disease, including immune cell invasion of the central nervous system, demyelination, and Nav1.8 upregulation in Purkinje neurons. Therefore, in a second series, we studied wildtype C57Bl/6 mice with EAE [9] and tested oral dosing of PF-01247324 for possible efficacy to improve cerebellar symptoms in this more complex, disease-relevant model. The results of this series of experiments are shown in Fig. 2. In C57Bl/6 mice with EAE that were administered vehicle only, symptom manifestation remained fairly stable over the six-hour observation period following dosing (Fig. 2A). However, in C57Bl/6 mice with EAE that received PF-01247324 by the oral route, a modest but significant improvement of cerebellar symptoms (ataxia, righting reflex, tail posture) was detected at 3 and 4 hours after administration of the drug when analyzed by performing paired t-tests comparing the hourly timepoints to pre-drug baseline (Fig. 2B). However, a two-way ANOVA with repeated measures showed only a marginally significant effect of Time (p = 0.05), but no Time*Treatment interaction (p = 0.19). We conclude that PF-01247324 showed a trend toward slightly improved symptoms in the EAE model, but the effect size was small and not statistically distinguishable from vehicle.


Oral administration of PF-01247324, a subtype-selective Nav1.8 blocker, reverses cerebellar deficits in a mouse model of multiple sclerosis.

Shields SD, Butt RP, Dib-Hajj SD, Waxman SG - PLoS ONE (2015)

Oral administration of PF-01247324 slightly improves MS-like deficits in the EAE model.EAE symptom progression was scored on a 0 to 6 scale [9], with 0.5-point gradations for intermediate scores, as follows: 0, normal; 1, flaccid tail; 2, impaired righting reflex or wobbly gait but no clear weakness; 3, weakness of both hindlimbs or paralysis of a single hindlimb; 4, complete hindlimb paralysis; 5, primarily recumbent and unable to ambulate; 6, death. A. C57Bl/6 mice with EAE that were administered vehicle had stable symptom scores over the 6 h observation period. (All timepoints p>0.05 compared to baseline (BL), paired t-tests. n = 19.) B. C57Bl/6 mice with EAE that were administered PF-01247324 showed a slight improvement in symptom scores after dosing, when analyzed with paired t-tests to compare individual timepoints to pre-drug BL. (1 h, p = 0.3299; 2 h, p = 0.5426; 3 h, p = 0.0493; 4 h, p = 0.0084; 5 h, p = 0.0555; 6 h, p = 0.6649; paired t-tests compared to BL. n = 20.) However, a two-way ANOVA did not show significant improvement compared to vehicle control. *, p<0.05 compared to BL, paired t-test.
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pone.0119067.g002: Oral administration of PF-01247324 slightly improves MS-like deficits in the EAE model.EAE symptom progression was scored on a 0 to 6 scale [9], with 0.5-point gradations for intermediate scores, as follows: 0, normal; 1, flaccid tail; 2, impaired righting reflex or wobbly gait but no clear weakness; 3, weakness of both hindlimbs or paralysis of a single hindlimb; 4, complete hindlimb paralysis; 5, primarily recumbent and unable to ambulate; 6, death. A. C57Bl/6 mice with EAE that were administered vehicle had stable symptom scores over the 6 h observation period. (All timepoints p>0.05 compared to baseline (BL), paired t-tests. n = 19.) B. C57Bl/6 mice with EAE that were administered PF-01247324 showed a slight improvement in symptom scores after dosing, when analyzed with paired t-tests to compare individual timepoints to pre-drug BL. (1 h, p = 0.3299; 2 h, p = 0.5426; 3 h, p = 0.0493; 4 h, p = 0.0084; 5 h, p = 0.0555; 6 h, p = 0.6649; paired t-tests compared to BL. n = 20.) However, a two-way ANOVA did not show significant improvement compared to vehicle control. *, p<0.05 compared to BL, paired t-test.
Mentions: Although L7–1.8TG mice can be seen as a simple model for one of the manifestations of MS, the EAE model is more realistic because it recapitulates more features of this complex disease, including immune cell invasion of the central nervous system, demyelination, and Nav1.8 upregulation in Purkinje neurons. Therefore, in a second series, we studied wildtype C57Bl/6 mice with EAE [9] and tested oral dosing of PF-01247324 for possible efficacy to improve cerebellar symptoms in this more complex, disease-relevant model. The results of this series of experiments are shown in Fig. 2. In C57Bl/6 mice with EAE that were administered vehicle only, symptom manifestation remained fairly stable over the six-hour observation period following dosing (Fig. 2A). However, in C57Bl/6 mice with EAE that received PF-01247324 by the oral route, a modest but significant improvement of cerebellar symptoms (ataxia, righting reflex, tail posture) was detected at 3 and 4 hours after administration of the drug when analyzed by performing paired t-tests comparing the hourly timepoints to pre-drug baseline (Fig. 2B). However, a two-way ANOVA with repeated measures showed only a marginally significant effect of Time (p = 0.05), but no Time*Treatment interaction (p = 0.19). We conclude that PF-01247324 showed a trend toward slightly improved symptoms in the EAE model, but the effect size was small and not statistically distinguishable from vehicle.

Bottom Line: Cerebellar symptoms significantly diminish quality of life in patients with multiple sclerosis (MS).PF-01247324 was administered by oral gavage at 1000 mg/kg; control groups received an equal volume of vehicle.These preclinical proof-of-concept data suggest that PF-01247324, its derivatives, or other Nav1.8-selective blockers merit further study for providing symptomatic therapy for cerebellar dysfunction in MS and related disorders.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut, United States of America; Rehabilitation Research Center, Veterans' Affairs Connecticut Healthcare System, West Haven, Connecticut, United States of America.

ABSTRACT
Cerebellar symptoms significantly diminish quality of life in patients with multiple sclerosis (MS). We previously showed that sodium channel Nav1.8, although normally restricted to peripheral somatosensory neurons, is upregulated in the cerebellum in MS, and that Nav1.8 expression is linked to ataxia and MS-like symptoms in mice. Furthermore, intracerebroventricular administration of the Nav1.8 blocker A-803467 temporarily reversed electrophysiological and behavioral manifestations of disease in a mouse MS model; unfortunately A-803467 is not orally bioavailable, diminishing the potential for translation to human patients. In the present study, we assessed the effect of per os (p.o.) dosing of a new orally bioavailable Nav1.8-selective blocker, PF-01247324, in transgenic mice expressing Nav1.8 in Purkinje neurons, and in wildtype mice in the experimental autoimmune encephalomyelitis (EAE) model. PF-01247324 was administered by oral gavage at 1000 mg/kg; control groups received an equal volume of vehicle. Behavioral assays of motor coordination, grip strength, and ataxia were performed. We observed significant improvements in motor coordination and cerebellar-like symptoms in mice that received PF-01247324 compared to control littermates that received vehicle. These preclinical proof-of-concept data suggest that PF-01247324, its derivatives, or other Nav1.8-selective blockers merit further study for providing symptomatic therapy for cerebellar dysfunction in MS and related disorders.

Show MeSH
Related in: MedlinePlus