1. Inefficient constitutive inhibition of P2X3 receptors by brain natriuretic peptide system contributes to sensitization of trigeminal sensory neurons in a genetic mouse model of familial hemiplegic migraine.
- Author
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Marchenkova A, Vilotti S, Ntamati N, van den Maagdenberg AM, and Nistri A
- Subjects
- Animals, Calcitonin Gene-Related Peptide Receptor Antagonists, Disease Models, Animal, Gene Knock-In Techniques, Mice, Migraine with Aura pathology, Models, Biological, Peptides, Cyclic pharmacology, Phenotype, Purinergic P2X Receptor Antagonists pharmacology, Receptors, Atrial Natriuretic Factor metabolism, Receptors, Calcitonin Gene-Related Peptide metabolism, Sensory Receptor Cells drug effects, Sensory Receptor Cells metabolism, TRPV Cation Channels metabolism, Trigeminal Ganglion drug effects, Trigeminal Ganglion metabolism, omega-Agatoxin IVA pharmacology, Migraine with Aura genetics, Migraine with Aura metabolism, Natriuretic Peptide, Brain metabolism, Receptors, Purinergic P2X3 metabolism, Sensory Receptor Cells pathology, Trigeminal Ganglion pathology
- Abstract
Background: On trigeminal ganglion neurons, pain-sensing P2X3 receptors are constitutively inhibited by brain natriuretic peptide via its natriuretic peptide receptor-A. This inhibition is associated with increased P2X3 serine phosphorylation and receptor redistribution to non-lipid raft membrane compartments. The natriuretic peptide receptor-A antagonist anantin reverses these effects. We studied whether P2X3 inhibition is dysfunctional in a genetic familial hemiplegic migraine type-1 model produced by introduction of the human pathogenic R192Q missense mutation into the mouse CACNA1A gene (knock-in phenotype). This model faithfully replicates several properties of familial hemiplegic migraine type-1, with gain-of-function of CaV2.1 Ca(2+) channels, raised levels of the algogenic peptide calcitonin gene-related peptide, and enhanced activity of P2X3 receptors in trigeminal ganglia., Results: In knock-in neurons, anantin did not affect P2X3 receptor activity, membrane distribution, or serine phosphorylation level, implying ineffective inhibition by the constitutive brain natriuretic peptide/natriuretic peptide receptor-A pathway. However, expression and functional properties of this pathway remained intact together with its ability to downregulate TRPV1 channels. Reversing the familial hemiplegic migraine type-1 phenotype with the CaV2.1-specific antagonist, ω-agatoxin IVA restored P2X3 activity to wild-type level and enabled the potentiating effects of anantin again. After blocking calcitonin gene-related peptide receptors, P2X3 receptors exhibited wild-type properties and were again potentiated by anantin., Conclusions: P2X3 receptors on mouse trigeminal ganglion neurons are subjected to contrasting modulation by inhibitory brain natriuretic peptide and facilitatory calcitonin gene-related peptide that both operate via complex intracellular signaling. In the familial hemiplegic migraine type-1 migraine model, the action of calcitonin gene-related peptide appears to prevail over brain natriuretic peptide, thus suggesting that peripheral inhibition of P2X3 receptors becomes insufficient and contributes to trigeminal pain sensitization., (© The Author(s) 2016.)
- Published
- 2016
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