pf-670462 and Anaphylaxis

The molecular clock network in mast cells has been shown to be a factor responsible for circadian regulation of allergic inflammation. PF670462 is a selective inhibitor of casein kinase 1δ and ε (CK1δ/ε) that control the posttranslational modification of clock proteins. The aims of this study were to evaluate the effects of PF670462 on gene and protein expression of FcεRI, the high-affinity IgE receptor, in canine mast cells and on IgE-mediated immediate-type cutaneous reactions in dogs. PF670462 decreased mRNA expression of FcεRIα and β, but not γ, and protein expression of FcεRI in a canine mast cell line. Furthermore, PF670462 suppressed IgE-mediated immediate-type cutaneous erythema in dogs. These findings indicate that CK1δ/ε function as regulators for FcεRI expression and IgE-mediated cutaneous reactions in dogs.

Topics: Anaphylaxis; Animals; Casein Kinase 1 epsilon; Casein Kinase Idelta; Dog Diseases; Dogs; Gene Expression Regulation; Immunoglobulin E; Mast Cells; Protein Kinase Inhibitors; Pyrimidines; Receptors, IgE; RNA, Messenger

The circadian clock temporally gates signaling through the high-affinity IgE receptor (FcεRI) in mast cells, thereby generating a marked day/night variation in allergic reactions. Thus manipulation of the molecular clock in mast cells might have therapeutic potential for IgE-mediated allergic reactions.. We determined whether pharmacologically resetting the molecular clock in mast cells or basophils to times when FcεRI signaling was reduced (ie, when core circadian protein period 2 [PER2] is upregulated) resulted in suppression of IgE-mediated allergic reactions.. We examined the effects of PF670462, a selective inhibitor of the key clock component casein kinase 1δ/ε, or glucocorticoid, both of which upregulated PER2 in mast cells, on IgE-mediated allergic reactions both in vitro and in vivo.. PF670462 or corticosterone (or dexamethasone) suppressed IgE-mediated allergic reactions in mouse bone marrow-derived mast cells or basophils and passive cutaneous anaphylactic reactions in mice in association with increased PER2 levels in mast cells or basophils. PF670462 or dexamethasone also ameliorated allergic symptoms in a mouse model of allergic rhinitis and downregulated allergen-specific basophil reactivity in patients with allergic rhinitis.. Pharmacologically resetting the molecular clock in mast cells or basophils to times when FcεRI signaling is reduced can inhibit IgE-mediated allergic reactions. The results suggest a new strategy for controlling IgE-mediated allergic diseases. Additionally, this study suggests a novel mechanism underlying the antiallergic actions of glucocorticoids that relies on the circadian clock, which might provide a novel insight into the pharmacology of this drug in allergic patients.

Topics: Anaphylaxis; Animals; Basophils; Biomarkers; Casein Kinase 1 epsilon; Casein Kinase Idelta; Circadian Clocks; Imidazoles; Immunologic Factors; Mast Cells; Mice; Period Circadian Proteins; Pyrimidines; Receptors, IgE; Rhinitis, Allergic; Treatment Outcome