Patient preferences for preventive migraine treatments among Canadian adults: A discrete choice experiment.

OBJECTIVE: To evaluate preferences for key attributes of injected or infused preventive migraine treatments and assess heterogeneity in preferences among Canadian participants with migraine. BACKGROUND: Current treatment options for migraine prevention differ in their attributes, including mode of administration, efficacy, and dosing frequency; preferences for such attributes can vary among patients. With the advent of new therapies, evidence demonstrating patient preferences for injected or infused preventive migraine treatments is necessary. METHODS: Canadian adults self-reporting a diagnosis of migraine completed a cross-sectional, internet-based survey that included a discrete choice experiment. Participants were presented with attributes of preventive migraine treatments, including speed of onset, durability of efficacy, mode of administration, administration setting, and dosing frequency. Latent class analysis (LCA) was used to identify subgroups of patients who differed in their treatment preferences. RESULTS: In total, 200 participants completed the survey. Participants' treatment preferences were most sensitive to improvements in the durability of effectiveness from "wears off 2 weeks before next dose" to "does not wear off before the next dose" (absolute difference in weights = |-0.95 to 1.07| = 2.02) and improvements from "cranial injections" to "intravenous infusions" (|-1.04 to 0.58| = 1.62); participants equally preferred self-injection and intravenous infusion from a health-care provider (mean weight = 0.58 and 0.47, respectively) as a route of administration over cranial injections (mean weight = -1.04). Three subgroups were identified with LCA: group one (n = 103) prioritized fast-acting and durable therapies, group two (n = 54) expressed aversion to cranial injections, and group three (n = 43) favored treatments administered in a health-care provider setting. CONCLUSIONS: In this sample of Canadian adults with migraine, we showed that durability of effectiveness and mode of administration are key attributes influencing patient preferences for preventive migraine treatments; however, certain groups of patients may differ in their treatment priorities. Our results highlight the need for patient-provider discussions regarding treatment attributes and consideration of patients' preferences when selecting a preventive migraine treatment.

Serotonin-induced cleavage of the atypical protein kinase C Apl III in Aplysia.

A constitutively active kinase, known as protein kinase Mζ (PKMζ), is proposed to act as a long-lasting molecular memory trace. While PKMζ is formed in rodents through translation of a transcript initiating in an intron of the protein kinase Cζ (PKCζ) gene, this transcript does not exist in Aplysia californica despite the fact that inhibitors of PKMζ erase memory in Aplysia in a fashion similar to rodents. We have previously shown that, in Aplysia, the ortholog of PKCζ, PKC Apl III, is cleaved by calpain to form a PKM after overexpression of PKC Apl III. We now show that kinase activity is required for this cleavage. We further use a FRET reporter to measure cleavage of PKC Apl III into PKM Apl III in live neurons using a stimulus that induces plasticity. Our results show that a 10 min application of serotonin induces cleavage of PKC Apl III in motor neuron processes in a calpain- and protein synthesis-dependent manner, but does not induce cleavage of PKC Apl III in sensory neuron processes. Furthermore, a dominant-negative PKM Apl III expressed in the motor neuron blocked the late phase of intermediate-term facilitation in sensory-motor neuron cocultures induced by 10 min of serotonin. In summary, we provide evidence that PKC Apl III is cleaved into PKM Apl III during memory formation, that the requirements for cleavage are the same as the requirements for the plasticity, and that PKM in the motor neuron is required for intermediate-term facilitation.

Epidemiology and treatment utilization for Canadian patients with migraine: a literature review.

The objective of this narrative review was to identify real-world evidence regarding the burden of migraine in Canada. We conducted a literature search in MEDLINE, Embase, and the Cochrane Database of Systematic Reviews for studies published between August 2010 and August 2020. Of the 3269 publications identified, 29 studies were included. Prevalence estimates varied widely across Canada, and mental health comorbidities were common. Individuals with migraine have a lower quality of life, detrimental impact on workforce productivity, and higher rates of health care resource utilization (HCRU), with HCRU and costs highest among those with chronic migraine. We found inconsistencies in care, including underutilization of medications such as triptans, and varied utilization of over-the-counter and prescription medications. Increased medication use was identified among those with chronic migraine, and only a small number of patients used migraine preventive medications. The burden of migraine in Canada is substantial. Reduced quality of life and workforce productivity, increased HCRU and costs, and underutilization of triptans and migraine preventive medications highlight an important need for more effective management of individuals with migraine.

Aplysia cell adhesion molecule and a novel protein kinase C activity in the postsynaptic neuron are required for presynaptic growth and initial formation of specific synapses.

To explore the role of both Aplysia cell adhesion molecule (ApCAM) and activity of specific protein kinase C (PKC) isoforms in the initial formation of sensory neuron synapses with specific postsynaptic targets (L7 but not L11), we examined presynaptic growth, initial synapse formation, and the expression of the presynaptic neuropeptide sensorin following cell-specific reduction of ApCAM or of a novel PKC activity. Synapse formation between sensory neurons and L7 begins by 3 h after plating and is accompanied by a rapid accumulation of a novel PKC to sites of synaptic interaction. Reducing ApCAM expression specifically from the surface of L7 blocks presynaptic growth and initial synapse formation, target-induced increase of sensorin in sensory neuron cell bodies and the rapid accumulation of the novel PKC to sites of interaction. Selective blockade of the novel PKC activity in L7, but not in sensory neurons, with injection of a dominant negative construct that interferes with the novel PKC activity, produces the same actions as downregulating ApCAM; blockade of presynaptic growth and initial synapse formation, and the target-induced increase of sensorin in sensory neuron cell bodies. The results indicate that signals initiated by postsynaptic cell adhesion molecule ApCAM coupled with the activation of a novel PKC in the appropriate postsynaptic neuron produce the retrograde signals required for presynaptic growth associated with initial synapse formation, and the target-induced expression of a presynaptic neuropeptide critical for synapse maturation.

Role of protein kinase C in the induction and maintenance of serotonin-dependent enhancement of the glutamate response in isolated siphon motor neurons of Aplysia californica.

Serotonin (5-HT) mediates learning-related facilitation of sensorimotor synapses in Aplysia californica. Under some circumstances 5-HT-dependent facilitation requires the activity of protein kinase C (PKC). One critical site of PKC's contribution to 5-HT-dependent synaptic facilitation is the presynaptic sensory neuron. Here, we provide evidence that postsynaptic PKC also contributes to synaptic facilitation. We investigated the contribution of PKC to enhancement of the glutamate-evoked potential (Glu-EP) in isolated siphon motor neurons in cell culture. A 10 min application of either 5-HT or phorbol ester, which activates PKC, produced persistent (> 50 min) enhancement of the Glu-EP. Chelerythrine and bisindolylmaleimide-1 (Bis), two inhibitors of PKC, both blocked the induction of 5-HT-dependent enhancement. An inhibitor of calpain, a calcium-dependent protease, also blocked 5-HT's effect. Interestingly, whereas chelerythrine blocked maintenance of the enhancement, Bis did not. Because Bis has greater selectivity for conventional and novel isoforms of PKC than for atypical isoforms, this result implicates an atypical isoform in the maintenance of 5-HT's effect. Although induction of enhancement of the Glu-EP requires protein synthesis (Villareal et al., 2007), we found that maintenance of the enhancement does not. Maintenance of 5-HT-dependent enhancement appears to be mediated by a PKM-type fragment generated by calpain-dependent proteolysis of atypical PKC. Together, our results suggest that 5-HT treatment triggers two phases of PKC activity within the motor neuron, an early phase that may involve conventional, novel or atypical isoforms of PKC, and a later phase that selectively involves an atypical isoform.

The atypical protein kinase C in Aplysia can form a protein kinase M by cleavage.

In vertebrates, a brain-specific transcript from the atypical protein kinase C (PKC) zeta gene encodes protein kinase M (PKM) zeta, a constitutively active kinase implicated in the maintenance of synaptic plasticity and memory. We have cloned the atypical PKC from Aplysia, PKC Apl III. We did not find a transcript in Aplysia encoding PKMzeta, and evolutionary analysis of atypical PKCs suggests formation of this transcript is restricted to vertebrates. Instead, over-expression of PKC Apl III in Aplysia sensory neurons leads to production of a PKM fragment of PKC Apl III. This cleavage was induced by calcium and blocked by calpain inhibitors. Moreover, nervous system enriched spliced forms of PKC Apl III show enhanced cleavage. PKC Apl III could also be activated through phosphorylation downstream of phosphoinositide 3-kinase. We suggest that PKM forms of atypical PKCs play a conserved role in memory formation, but the mechanism of formation of these kinases has changed over evolution.