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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 partially reverses motor incoordination in transgenic mice overexpressing Nav1.8 in cerebellar Purkinje neurons.A. Latency to fall from an inverted wire grid was measured in L7–1.8TG mice administered either PF-01247324 or vehicle, and in their wildtype littermates. Behavioral testing was performed one hour after dosing. Differences between the three groups were significant (one-way ANOVA, p = 0.0014). L7–1.8TG mice in the vehicle group performed significantly worse than WT mice. L7–1.8TG mice that received oral dosing of PF-01247324 had significantly improved performance in this assay. B. In the rotarod test, significant differences in motor coordination were observed (one-way ANOVA, p = 0.0006). L7–1.8TG mice in the vehicle group were able to stay on the rotating beam for less time than WT mice, indicating a deficit in motor coordination. Oral administration of PF-01247324 to L7–1.8TG mice significantly improved their performance compared to vehicle-treated mice of the same genotype. C. Grip strength was similar in each of the three groups. One-way ANOVA, p = 0.7560. *, p<0.05 compared to WT vehicle group; #, p<0.05 compared to L7–1.8TG vehicle group, Dunnett’s post-hoc test. WT+vehicle, n = 8; L7–1.8TG+vehicle, n = 7; L7–1.8TG+PF-01247324, n = 6.
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pone.0119067.g001: Oral administration of PF-01247324 partially reverses motor incoordination in transgenic mice overexpressing Nav1.8 in cerebellar Purkinje neurons.A. Latency to fall from an inverted wire grid was measured in L7–1.8TG mice administered either PF-01247324 or vehicle, and in their wildtype littermates. Behavioral testing was performed one hour after dosing. Differences between the three groups were significant (one-way ANOVA, p = 0.0014). L7–1.8TG mice in the vehicle group performed significantly worse than WT mice. L7–1.8TG mice that received oral dosing of PF-01247324 had significantly improved performance in this assay. B. In the rotarod test, significant differences in motor coordination were observed (one-way ANOVA, p = 0.0006). L7–1.8TG mice in the vehicle group were able to stay on the rotating beam for less time than WT mice, indicating a deficit in motor coordination. Oral administration of PF-01247324 to L7–1.8TG mice significantly improved their performance compared to vehicle-treated mice of the same genotype. C. Grip strength was similar in each of the three groups. One-way ANOVA, p = 0.7560. *, p<0.05 compared to WT vehicle group; #, p<0.05 compared to L7–1.8TG vehicle group, Dunnett’s post-hoc test. WT+vehicle, n = 8; L7–1.8TG+vehicle, n = 7; L7–1.8TG+PF-01247324, n = 6.

Mentions: Transgenic mice overexpressing Nav1.8 in cerebellar Purkinje neurons in the absence of any other MS-like symptoms were used. These mice are designated L7–1.8TG mice and were described previously [6]. L7–1.8TG mice are significantly impaired in performing coordinated motor behaviors, including difficulty navigating an inverted wire grid and shorter latency to fall while walking on a rotating beam (rotarod). In blinded experiments, we administered either PF-01247324 or vehicle to L7–1.8TG mice via oral gavage and performed behavioral assessment of motor coordination one hour later. An additional control group consisted of wildtype littermates of L7–1.8TG mice (WT) that were administered vehicle. Fig. 1 shows the results. In the inverted wire grid test, L7–1.8TG mice that received vehicle performed significantly worse than WT mice that received vehicle, reproducing our previous results on the deleterious effects of ectopic expression of Nav1.8 in the cerebellum (Fig. 1A). However, L7–1.8TG mice that were administered PF-01247324 showed a significant improvement in motor coordination in this assay compared to vehicle-treated L7–1.8TG mice (one-way ANOVA, p<0.05; followed by Dunnett’s post-hoc test). Similarly, on the rotarod test, vehicle-treated L7–1.8TG mice performed much worse than vehicle-treated WT mice, and administration of PF-01247324 significantly improved the ability of L7–1.8TG mice to sustain control while walking on the rotating beam (Fig. 1B). The effect of the transgenic mutation, as well as the effect of PF-01247324, was independent of any effect on the subjects’ grip strength (Fig. 1C). Because in L7–1.8TG mice the underlying cause of motor incoordination is ectopic Nav1.8 expression in cerebellar Purkinje neurons, and administration of a selective Nav1.8 blocker improved coordination, we suggest that these data may represent behavioral evidence of target engagement by the compound.


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 partially reverses motor incoordination in transgenic mice overexpressing Nav1.8 in cerebellar Purkinje neurons.A. Latency to fall from an inverted wire grid was measured in L7–1.8TG mice administered either PF-01247324 or vehicle, and in their wildtype littermates. Behavioral testing was performed one hour after dosing. Differences between the three groups were significant (one-way ANOVA, p = 0.0014). L7–1.8TG mice in the vehicle group performed significantly worse than WT mice. L7–1.8TG mice that received oral dosing of PF-01247324 had significantly improved performance in this assay. B. In the rotarod test, significant differences in motor coordination were observed (one-way ANOVA, p = 0.0006). L7–1.8TG mice in the vehicle group were able to stay on the rotating beam for less time than WT mice, indicating a deficit in motor coordination. Oral administration of PF-01247324 to L7–1.8TG mice significantly improved their performance compared to vehicle-treated mice of the same genotype. C. Grip strength was similar in each of the three groups. One-way ANOVA, p = 0.7560. *, p<0.05 compared to WT vehicle group; #, p<0.05 compared to L7–1.8TG vehicle group, Dunnett’s post-hoc test. WT+vehicle, n = 8; L7–1.8TG+vehicle, n = 7; L7–1.8TG+PF-01247324, n = 6.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4352054&req=5

pone.0119067.g001: Oral administration of PF-01247324 partially reverses motor incoordination in transgenic mice overexpressing Nav1.8 in cerebellar Purkinje neurons.A. Latency to fall from an inverted wire grid was measured in L7–1.8TG mice administered either PF-01247324 or vehicle, and in their wildtype littermates. Behavioral testing was performed one hour after dosing. Differences between the three groups were significant (one-way ANOVA, p = 0.0014). L7–1.8TG mice in the vehicle group performed significantly worse than WT mice. L7–1.8TG mice that received oral dosing of PF-01247324 had significantly improved performance in this assay. B. In the rotarod test, significant differences in motor coordination were observed (one-way ANOVA, p = 0.0006). L7–1.8TG mice in the vehicle group were able to stay on the rotating beam for less time than WT mice, indicating a deficit in motor coordination. Oral administration of PF-01247324 to L7–1.8TG mice significantly improved their performance compared to vehicle-treated mice of the same genotype. C. Grip strength was similar in each of the three groups. One-way ANOVA, p = 0.7560. *, p<0.05 compared to WT vehicle group; #, p<0.05 compared to L7–1.8TG vehicle group, Dunnett’s post-hoc test. WT+vehicle, n = 8; L7–1.8TG+vehicle, n = 7; L7–1.8TG+PF-01247324, n = 6.
Mentions: Transgenic mice overexpressing Nav1.8 in cerebellar Purkinje neurons in the absence of any other MS-like symptoms were used. These mice are designated L7–1.8TG mice and were described previously [6]. L7–1.8TG mice are significantly impaired in performing coordinated motor behaviors, including difficulty navigating an inverted wire grid and shorter latency to fall while walking on a rotating beam (rotarod). In blinded experiments, we administered either PF-01247324 or vehicle to L7–1.8TG mice via oral gavage and performed behavioral assessment of motor coordination one hour later. An additional control group consisted of wildtype littermates of L7–1.8TG mice (WT) that were administered vehicle. Fig. 1 shows the results. In the inverted wire grid test, L7–1.8TG mice that received vehicle performed significantly worse than WT mice that received vehicle, reproducing our previous results on the deleterious effects of ectopic expression of Nav1.8 in the cerebellum (Fig. 1A). However, L7–1.8TG mice that were administered PF-01247324 showed a significant improvement in motor coordination in this assay compared to vehicle-treated L7–1.8TG mice (one-way ANOVA, p<0.05; followed by Dunnett’s post-hoc test). Similarly, on the rotarod test, vehicle-treated L7–1.8TG mice performed much worse than vehicle-treated WT mice, and administration of PF-01247324 significantly improved the ability of L7–1.8TG mice to sustain control while walking on the rotating beam (Fig. 1B). The effect of the transgenic mutation, as well as the effect of PF-01247324, was independent of any effect on the subjects’ grip strength (Fig. 1C). Because in L7–1.8TG mice the underlying cause of motor incoordination is ectopic Nav1.8 expression in cerebellar Purkinje neurons, and administration of a selective Nav1.8 blocker improved coordination, we suggest that these data may represent behavioral evidence of target engagement by the compound.

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