Pharmacogenomic study-A pilot study of the effect of pharmacogenomic phenotypes on the adequate dosing of verapamil for migraine prevention.

OBJECTIVE: To investigate factors affecting the efficacy and tolerability of verapamil for migraine prevention using individual pharmacogenomic phenotypes. BACKGROUND: Verapamil has a wide range of dosing in headache disorders without reliable tools to predict the optimal doses for an individual. METHODS: This is a retrospective chart review examining adults with existing pharmacogenomic reports at Mayo Clinic who had used verapamil for migraine. Effects of six cytochrome P450 phenotypes on the doses of verapamil for migraine prevention were assessed. RESULTS: Our final analysis included 33 migraine patients (82% with aura). The mean minimum effective and maximum tolerable doses of verapamil were 178.2(20-320) mg and 227.9(20-480) mg. A variety of CYP2C9, CYP2D6, and CYP3A5 phenotypes were found, without significant association with the verapamil doses after adjusting for age, sex, body mass index, and smoking status. CONCLUSIONS: We demonstrated a wide range of effective and tolerable verapamil doses used for migraine in a cohort with various pharmacogenomic phenotypes.

Differences in Neuropathology between Nitroglycerin-Induced Mouse Models of Episodic and Chronic Migraine.

Multiple animal models of migraine have been used to develop new therapies. Understanding the transition from episodic (EM) to chronic migraine (CM) is crucial. We established models mimicking EM and CM pain and assessed neuropathological differences. EM and CM models were induced with single NTG or multiple injections over 9 days. Mechanical hypersensitivity was assessed. Immunofluorescence utilized c-Fos, NeuN, and Iba1. Proinflammatory and anti-inflammatory markers were analyzed. Neuropeptides (CGRP, VIP, PACAP, and substance P) were assessed. Mechanical thresholds were similar. Notable neuropathological distinctions were observed in Sp5C and ACC. ACC showed increased c-Fos and NeuN expression in CM (p < 0.001) and unchanged in EM. Sp5C had higher c-Fos and NeuN expression in EM (p < 0.001). Iba1 was upregulated in Sp5C of EM and ACC of CM (p < 0.001). Proinflammatory markers were strongly expressed in Sp5C of EM and ACC of CM. CGRP expression was elevated in both regions and was higher in CM. VIP exhibited higher levels in the Sp5C of EM and ACC of CM, whereas PACAP and substance P were expressed in the Sp5C in both models. Despite similar thresholds, distinctive neuropathological differences in Sp5C and ACC between EM and CM models suggest a role in the EM to CM transformation.

Rebalancing NOX2/Nrf2 to limit inflammation and oxidative stress across gut-brain axis in migraine.

Migraine is one of the most common neurological illnesses, and it is characterized by complicated neurobiology. It was confirmed the influence of inflammation and oxidative stress in migraines and also in distal organs such as the intestine. Indeed, the constant bidirectional communication between the Central Nervous System (CNS) and the gastrointestinal (GI) tract, known as the gut-brain axis, has become an attractive target involved in different human disorders. Herein, we explored the role of NADPH oxidase 2 (NOX2) in nitroglycerin (NTG)-induced migraine in mice models to discover the mechanism by which, during migraine attack, oxidative stress is sustained within trigeminal neurons and GI. Considering the inverse relationship between NOX2 and Nrf2, Nrf2 upregulation seems to be a promising approach to decrease NOX2 expression and consequently limit oxidative stress and inflammation spread in neurological and non-neurological diseases. With this aim, we exploited tempol's Nrf2-inducer ability to better understand the involvement of Nrf2/NOX2 axis in migraine and associated GI comorbidities. Behavioral tests confirmed that tempol, in a dose-dependent manner, moderated clinical signs of migraine and abdominal pain. Moreover, we demonstrated that the decrease in migraine-related symptomatology was strongly linked to the modulation of Nrf2/NOX2 signaling pathway in the brain and colon. In the brain, the rebalancing of Nrf2/NOX2 prevented neuronal loss, decreased glia reactivity while inhibiting NF-κB and NLRP3 inflammasome activation. In the colon, Nrf2 upregulation and consequent NOX2 decrease reduced the histological damage, mast cells infiltration as well as tumor necrosis factor (TNF)-α and interleukin (IL)-1ß release. Furthermore, the attenuation of inflammation and oxidative stress led to the restoration of the intestinal barrier through TJs replacement. Taken as a whole, data suggested that the regulation of Nrf2/NOX2 balance is a successful way to reduce neurological and related intestinal impairments during migraine and could be of relevance for migraine-like attacks in humans.

Integration of single-nucleus RNA sequencing and network disturbance to elucidate crosstalk between multicomponent drugs and trigeminal ganglia cells in migraine.

ETHNOPHARMACOLOGICAL RELEVANCE: Migraine is caused by hyperactivity of the trigeminovascular system, where trigeminal ganglia (TG) plays an important role. TG is composed of multiple neuronal and non-neuronal cell types, which is related to "neuro-inflammation-vascular" disorder in migraine. Tou Tong Ning capsule (TTNC), a CFDA-approved traditional Chinese medicine for treating migraine, has the characteristics of "multicomponents, multitargets, multipathways". AIM OF THE STUDY: To clarify the mechanism of TTNC and elucidate crosstalk between multicomponent drugs and neuronal and non-neuronal functions and cells in migraine. MATERIALS AND METHODS: We integrated single-nucleus RNA sequencing and a quantitative evaluation algorithm of the disturbance of multitarget drugs on the disease network and explored the specific pathology of migraine and corresponding compounds. A cerebrovascular smooth muscle spasmolytic activity experiment was carried out to verify the results of the bioinformatics analysis. RESULTS: TTNC exhibited its regulation activities in neuronal and non-neuronal aspects based on drugs attack to four subnetworks and cell specific networks, which explored the MoA of TTNC in comprehensive and refined perspectives. Compared to neuronal regulation, TTNC showed more significant attack score on non-neuronal biological function (smooth muscle and vessel). And TTNC compound clusters C1, C6 and C7, targeting non-neuronal function and cells, had larger group area than C10, C4 and C6 for neuronal function and cell, which implied that TTNC may mainly regulate the non-neuronal function, e.g., vessel smooth muscle contraction. Contraction of cerebrovascular smooth muscle of mice ex vivo confirmed the vasodilation activity of TTNC and active compounds from C1, C6, C9 (Emodin, Luteolin and Levistilide A). Literature mining confirmed the vasospasmodolytic activity and neuroprotective effect of TTNC. CONCLUSIONS: The study found that TTNC may primarily alleviate non-neuronal functional disorders in migraine by relaxing cerebral vascular smooth muscle cell spasm to alleviate migraine. Integrating single-nucleus RNA sequencing data and network disturbance tools provides a new strategy for the pharmacological mechanism of multicomponent drugs through cell subtyping.

A new gene for autosomal dominant facial palsy/migraine identified in a family by whole exome sequencing.

BACKGROUND: Facial palsy manifests as unilateral or bilateral weakness and inability to move some of the facial muscles. The aetiology may be different including idiopathic, trauma, infections or brain tumours or it can be associated with chronic neurological diseases. For instance, in recurrent migraine, an increased risk of idiopathic facial palsy (often unilateral) has been observed. Migraine is a neurovascular disorder characterized by mild to severe intensity of headaches, often associated with neuro-ophthalmological symptoms. METHODS: A family is reported where five members were affected by facial palsy associated with other clinical features including migraine, diplopia, facial swelling, eye conjunctivitis following a vertical transmission. Whole exome sequencing was performed in three members (two affected and one healthy) in order to identify potential variants causative of their phenotype. RESULTS: A missense variant c.304G>A was found leading to the p.(Ala102Thr) substitution in the TRPM8 gene, previously related to migraine by genome wide association studies. This variant was classified as deleterious by several predictor tools, and the mutant residue was predicted to alter the protein structure in terms of flexibility and interactions with the surrounding residues. CONCLUSION: These findings suggest that TRPM8 could be a new causative gene further linking migraine and recurrent facial palsy.

Effect of genetic liability to migraine and its subtypes on breast cancer: a mendelian randomization study.

BACKGROUND: The relationship between migraine and breast cancer risk has generated conflicting findings. We attempted to assess the association between migraine and breast cancer risk using Mendelian randomization (MR) analysis. METHODS: We selected genetic instruments associated with migraine from a recently published genome-wide association studies (GWAS). Inverse variant weighted (IVW) analysis was adopted as the main method, and we also performed the weighted-median method and the MR‒Egger, MR pleiotropy residual sum and outlier (MR-PRESSO), and MR Robust Adjusted Profile Score (MR-RAPS) methods as supplements. RESULTS: Our MR suggested that any migraine (AM) was a risk factor for overall breast cancer (IVW: odds ratio (OR) = 1.072, 95% confidence intervals (CI) = 1.035-1.110, P = 8.78 × 10- 5, false discovery rate (FDR) = 7.36 × 10- 4) and estrogen receptor-positive (ER+) breast cancer (IVW: OR = 1.066, 95% CI = 1.023-1.111, P = 0.0024; FDR = 0.0108) but not estrogen receptor-negative (ER-) breast cancer. In its subtype analysis, women with a history of migraine without aura (MO) had an increased risk of ER- breast cancer (IVW: OR = 1.089, 95% CI = 1.019-1.163, P = 0.0118, FDR = 0.0354), and MO was suggestively associated with the risk of overall breast cancer (FDR > 0.05 and IVW P < 0.05). No significant heterogeneity or horizontal pleiotropy was found in the sensitivity analysis. CONCLUSION: This study suggested that women with AM have an increased risk of overall breast cancer and ER + breast cancer. MO was suggestively associated with the risk of overall breast cancer and ER- breast cancer.

Calcitonin/PAC1 receptor splice variants: a blind spot in migraine research.

The neuropeptides calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating polypeptide (PACAP) and their receptors are linked to migraine neurobiology. Recent antimigraine therapeutics targeting the signaling of these neuropeptides are effective; however, some patients respond suboptimally, indicating an incomplete understanding of migraine pathophysiology. The CGRP- and PACAP-responsive receptors can be differentially spliced. It is known that receptor splice variants can have different pathophysiological effects in other receptor-mediated pain pathways. Despite considerable knowledge on the structural and pharmacological differences of the CGRP- and PACAP-responsive receptor splice variants and their expression in migraine-relevant tissues, their role in migraine is rarely considered. Here we shine a spotlight on the calcitonin and PACAP (PAC1) receptor splice variants and examine what implications they may have for drug activity and design.

Melkersson-Rosenthal Syndrome and Migraine: A New Phenotype Associated with SCN1A Variants?

Peripheral facial palsy rarely occurs as part of Melkersson-Rosenthal syndrome (MRS), which is characterized by the classical triad of tongue cheilitis, recurrent episodes of orofacial swelling, and palsy. MRS is a disorder with variable expressivity and clinical as well as genetic heterogeneity; however, the causative gene remains to be identified. Migraine is a common neurological disorder, presenting with or without aura, which may be associated with neurological symptoms. The classical example of monogenic migraine is familial hemiplegic migraine (FHM), which has phenotypic variability in carriers of variants in the same gene or even carriers of the same variant. We present a family in which two sisters displayed recurrent migraines, one of which presented recurrent facial palsy and had clinical diagnosis of MRS. We performed WES and Sanger sequencing for segregation analysis in the available family members. We identified a c.3521C>G missense heterozygous variant in SCN1A carried only by the affected sister. Variants in the SCN1A gene can cause a spectrum of early-onset epileptic encephalopathies, in addition to FHM; therefore, our finding reasonably explains the proband phenotype, in which the main symptom was recurrent facial palsy. This report also adds knowledge to the clinical spectrum of SCN1A alterations and suggests a potential overlap between MRS and FHM.

Peripheral CCL2-CCR2 signalling contributes to chronic headache-related sensitization.

Migraine, especially chronic migraine, is highly debilitating and still lacks effective treatment. The persistent headache arises from activation and sensitization of primary afferent neurons in the trigeminovascular pathway, but the underlying mechanisms remain incompletely understood. Animal studies indicate that signalling through chemokine C-C motif ligand 2 (CCL2) and C-C motif chemokine receptor 2 (CCR2) mediates the development of chronic pain after tissue or nerve injury. Some migraine patients had elevated CCL2 levels in CSF or cranial periosteum. However, whether the CCL2-CCR2 signalling pathway contributes to chronic migraine is not clear. Here, we modelled chronic headache with repeated administration of nitroglycerin (NTG, a reliable migraine trigger in migraineurs) and found that both Ccl2 and Ccr2 mRNA were upregulated in dura and trigeminal ganglion (TG) tissues that are implicated in migraine pathophysiology. In Ccl2 and Ccr2 global knockout mice, repeated NTG administration did not evoke acute or persistent facial skin hypersensitivity as in wild-type mice. Intraperitoneal injection of CCL2 neutralizing antibodies inhibited chronic headache-related behaviours induced by repeated NTG administration and repetitive restraint stress, suggesting that the peripheral CCL2-CCR2 signalling mediates headache chronification. We found that CCL2 was mainly expressed in TG neurons and cells associated with dura blood vessels, whereas CCR2 was expressed in subsets of macrophages and T cells in TG and dura but not in TG neurons under both control and disease states. Deletion of Ccr2 gene in primary afferent neurons did not alter NTG-induced sensitization, but eliminating CCR2 expression in either T cells or myeloid cells abolished NTG-induced behaviours, indicating that both CCL2-CCR2 signalling in T cells and macrophages are required to establish chronic headache-related sensitization. At cellular level, repeated NTG administration increased the number of TG neurons that responded to calcitonin-gene-related peptide (CGRP) and pituitary adenylate cyclase activating polypeptide (PACAP) as well as the production of CGRP in wild-type but not Ccr2 global knockout mice. Lastly, co-administration of CCL2 and CGRP neutralizing antibodies was more effective in reversing NTG-induced behaviours than individual antibodies. Taken together, these results suggest that migraine triggers activate CCL2-CCR2 signalling in macrophages and T cells. This consequently enhances both CGRP and PACAP signalling in TG neurons, ultimately leading to persistent neuronal sensitization underlying chronic headache. Our work not only identifies the peripheral CCL2 and CCR2 as potential targets for chronic migraine therapy, but also provides proof-of-concept that inhibition of both peripheral CGRP and CCL2-CCR2 signalling is more effective than targeting either pathway alone.

Molecular and Cellular Neurobiology of Circadian and Circannual Rhythms in Migraine: A Narrative Review.

Migraine-a primary headache-has circadian and circannual rhythms in the onset of attacks. The circadian and circannual rhythms involve the hypothalamus, which is strongly associated with pain processing in migraines. Moreover, the role of melatonin in circadian rhythms has been implied in the pathophysiology of migraines. However, the prophylactic effect of melatonin in migraines is controversial. Calcitonin gene-related peptide (CGRP) has recently attracted attention in the pathophysiology and treatment of migraines. Pituitary adenylate cyclase-activating peptide (PACAP)-a neuropeptide identical to CGRP-is a potential therapeutic target after CGRP. PACAP is involved in the regulation of circadian entrainment to light. This review provides an overview of circadian and circannual rhythms in the hypothalamus and describes the relationship between migraines and the molecular and cellular neurobiology of circadian and circannual rhythms. Furthermore, the potential clinical applications of PACAP are presented.

Common Clinical and Molecular Pathways between Migraine and Sarcoidosis.

Migraine and sarcoidosis are two distinct medical conditions that may have some common biological and clinical pathways. Sarcoidosis is a chronic granulomatous disease characterized by the formation of granulomas in various organs, including the lungs, skin, cardiovascular system, lymph nodes, and brain. Migraine is a common comorbidity in sarcoidosis patients and a common neurological disorder characterized by recurrent headaches that can be accompanied by other symptoms, such as nausea, vomiting, and sensitivity to light and sound. There have been several reports of individuals with neurosarcoidosis experiencing migraines, though the exact relationship between the two disorders is not well understood. Both conditions have been associated with inflammation and the activation of the immune system. In sarcoidosis, the formation of granulomas is thought to be an immune response to the presence of an unknown antigen. Similarly, the pain and other symptoms associated with migraines are thought to be caused by inflammation in the brain and the surrounding blood vessels. There is also evidence to suggest an interplay of environmental and genetic factors playing a role in both conditions, but evidence is inconsistent with the hypothesis of shared genetic susceptibility. This review aims to illustrate common clinical and biological pathways between migraine and sarcoidosis, including inflammation and dysregulation of the immune system, with a focus on the cumulative burden of concurrent disorders and therapeutic implications.

Enlightening the association between TNF-α -308 G > A and migraine: a meta-analysis with meta-regression and trial sequential analysis.

BACKGROUND: Migraine is a complex neurological disorder that is characterized by a "lower threshold of neuronal hyperexcitability" with distinctive periodicity and complex vascular dysfunction. Genetic factors have impacted incredibly on the susceptibility of migraine and one such example is the TNF-α 308G > A. AIM: Therefore, we aim to provide a glimpse of the association of the TNF-α 308G > A risk on the susceptibility of migraine. METHOD: The pooled odds ratio with the associated 95% of confidence interval were calculated using different genetic models. Heterogeneity was accessed by using Cochran's Q Test and I2 statistics and Begg's and Egger's tests were used for finding the publication bias, tests were two-sided, and a p-value of < 0.05 was considered statistically significant. The Trial Sequential Analysis with Meta-regression Analysis were also utilized to find out the sample size requirement for meta-analysis to avoid type I error and source of heterogeneity respectively. RESULT: A total of 13 studies with cases: 7193 and controls: 23,091 were included and after using different genetic models, no overall association with migraine and its clinical subtype migraine with aura was observed (Allele model "OR: 1.28, 95% C.I. [0.96-1.69] and OR: 0.99,95% C.I. [0.69-1.42]) respectively. Interestingly, after sub-grouping using the "ethnicity criteria" in the migraine group, it was observed that the allelic genetic model and the dominant model were found to be significantly associated with the Asian ethnic group (OR: 1.79, 95% C.I. [1.13-2.84], and OR: 1.85, 95% C.I. [1.0927; 3.1580]. CONCLUSION: In conclusion, the present meta-analysis has provided evidence that 308G > A increases the risk of migraine only in the Asian population.

Nutrition and Calcitonin Gene Related Peptide (CGRP) in Migraine.

Targeting calcitonin gene-related peptide (CGRP) and its receptor by antibodies and antagonists was a breakthrough in migraine prevention and treatment. However, not all migraine patients respond to CGRP-based therapy and a fraction of those who respond complain of aliments mainly in the gastrointestinal tract. In addition, CGRP and migraine are associated with obesity and metabolic diseases, including diabetes. Therefore, CGRP may play an important role in the functioning of the gut-brain-microflora axis. CGRP secretion may be modulated by dietary compounds associated with the disruption of calcium signaling and upregulation of mitogen-activated kinase phosphatases 1 and 3. CGRP may display anorexigenic properties through induction of anorexigenic neuropeptides, such as cholecystokinin and/or inhibit orexigenic neuropeptides, such as neuropeptide Y and melanin-concentrating hormone CH, resulting in the suppression of food intake, functionally coupled to the activation of the hypothalamic 3',5'-cyclic adenosine monophosphate. The anorexigenic action of CGRP observed in animal studies may reflect its general potential to control appetite/satiety or general food intake. Therefore, dietary nutrients may modulate CGRP, and CGRP may modulate their intake. Therefore, anti-CGRP therapy should consider this mutual dependence to increase the efficacy of the therapy and reduce its unwanted side effects. This narrative review presents information on molecular aspects of the interaction between dietary nutrients and CGRP and their reported and prospective use to improve anti-CGRP therapy in migraine.

Cross-Trait Mendelian Randomization Study to Investigate Whether Migraine Is a Risk Factor for Multiple Sclerosis.

BACKGROUND AND OBJECTIVES: Migraine is common among people with multiple sclerosis (MS), but the reasons for this are unknown. We tested 3 hypothesized mechanisms for this observed comorbidity, including migraine is a risk factor of MS, genetic variants are shared between the conditions, and migraine is because of MS. METHODS: Data were from 2 sources: publicly available summary statistics from genome-wide association studies of MS (N = 115,748) and migraine (N = 375,752 and N = 361,141) and a case-control study of MS recruited from the Kaiser Permanente Northern California Health Plan (N = 1,991). For the latter participants, migraine status was ascertained using a validated electronic health record migraine probability algorithm or self-report. Using the public summary statistics, we used 2-sample Mendelian randomization to test whether a migraine genetic instrumental variable was associated with MS. We used linkage disequilibrium score regression and LOGODetect to ascertain whether MS and migraine shared genetic variants across the genome and regionally. Using the Northern California MS cohort, we used logistic regression to identify whether people with both MS and migraine had different odds of clinical characteristics (e.g., age at MS onset, Perceived Deficits Questionnaire, and depression) or MS-specific risk factors (e.g., body mass index, smoking status, and infectious mononucleosis status) compared with people with MS without migraine. RESULTS: We did not find evidence supporting migraine as a causal risk factor of MS (p = 0.29). We did, however, identify 4 major histocompatibility complex (MHC) loci shared between MS and migraine. Among the Northern California MS cohort, 774 (39%) experienced migraine. People with both MS and migraine from this cohort were more likely to ever smoke (odds ratio [OR] = 1.30, 95% CI: 1.08-1.57), have worse self-reported cognitive deficits (OR = 1.04, 95% CI: 1.02-1.06), and ever experience depression (OR = 1.48, 95% CI: 1.22-1.80). DISCUSSION: Our findings do not support migraine as a causal risk factor of MS. Several genetic variants, particularly in the MHC, may account for some of the overlap. It seems likely that migraine within the context of MS is because of MS. Identifying what increases the risk of migraine within MS might lead to an improved treatment and quality of life.

An Association Study of ESR1-XbaI and PvuII Gene Polymorphism in Migraine Susceptibility in the Jammu Region.

INTRODUCTION: Migraine is a neurovascular disorder and is clinically characterized by episodic attacks of mild to severe headaches. Due to the involvement of multiple environmental and genetic factors, it has become a much more complex neurological condition to understand. Apart from the environmental variables, a plethora of genes have been implicated, and one such example is ESR1. The present study was focused to find out the association of two important polymorphisms, namely, PvuII and XbaI of the ESR1 with migraine in the population of Jammu and Kashmir (UT). METHODS: The PCR-RFLP genotyping method was utilized to detect PvuII and XbaI polymorphism, and the result was confirmed by statistical analysis. RESULTS: Although we did not find a signification association of ESR-PvuII polymorphism with migraine susceptibility {OR: 1.14 at 95% CI [0.76-1.71] (p value 0.5)}, a strong association was found with the clinical subtype of migraine; migraine with aura (MA) {OR: 2.014 at 95% CI [1.069-3.792] (p value 0.028)}. Furthermore, a significant association of ESR-XbaI polymorphism was observed with migraine {OR: 1.908 at 95% CI [1.252-2.907] (p value 0.002) and its both clinical subtypes; migraine without aura (MO) {OR: 1.870 at 95% CI [1.186-2.950] (p value 0.006)} and MA {OR: 2.014 at 95% CI [1.069-3.792] (p value 0.028)}. CONCLUSION: In conclusion, ESR1-XbaI polymorphism is significantly associated with migraine risk including both subtypes (MA and MO) in the North Indian population of Jammu.

Association of LTA and SOD Gene Polymorphisms with Cerebral White Matter Hyperintensities in Migraine Patients.

White matter hyperintensities (WMHs) in migraine could be related to inflammatory and antioxidant events. The aim of this study is to verify whether migraine patients with WMHs carry a genetic pro-inflammatory/pro-oxidative status. To test this hypothesis, we analyzed lymphotoxin alpha (LTA; rs2071590T and rs2844482G) and superoxide dismutase 1 (SOD1; rs2234694C) and 2 (SOD2; rs4880T) gene polymorphisms (SNPs) in 370 consecutive patients affected by episodic (EM; n = 251) and chronic (CM; n = 119) migraine and in unrelated healthy controls (n = 100). Brain magnetic resonance was available in 183/370 patients. The results obtained show that genotypes and allele frequencies for all tested SNPs did not differ between patients and controls. No association was found between single SNPs or haplotypes and sex, migraine type, cardiovascular risk factors or disorders. Conversely, the LTA rs2071590T (OR = 2.2) and the SOD1 rs2234694C (OR = 4.9) alleles were both associated with WMHs. A four-loci haplotype (TGCT haplotype: rs2071590T/rs2844482G/rs2234694C/rs4880T) was significantly more frequent in migraineurs with WMHs (7 of 38) compared to those without WMHs (4 of 134; OR = 8.7). We may, therefore, conclude by suggesting that that an imbalance between pro-inflammatory/pro-oxidative and antioxidant events in genetically predisposed individuals may influence the development of WMHs.

PAC1, VPAC1, and VPAC2 Receptor Expression in Rat and Human Trigeminal Ganglia: Characterization of PACAP-Responsive Receptor Antibodies.

Pituitary adenylate cyclase-activating peptide (PACAP) is a neuropeptide expressed in the trigeminal ganglia (TG). The TG conducts nociceptive signals in the head and may play roles in migraine. PACAP infusion provokes headaches in healthy individuals and migraine-like attacks in patients; however, it is not clear whether targeting this system could be therapeutically efficacious. To effectively target the PACAP system, an understanding of PACAP receptor distribution is required. Therefore, this study aimed to characterize commercially available antibodies and use these to detect PACAP-responsive receptors in the TG. Antibodies were initially validated in receptor transfected cell models and then used to explore receptor expression in rat and human TG. Antibodies were identified that could detect PACAP-responsive receptors, including the first antibody to differentiate between the PAC1n and PAC1s receptor splice variants. PAC1, VPAC1, and VPAC2 receptor-like immunoreactivity were observed in subpopulations of both neuronal and glial-like cells in the TG. In this study, PAC1, VPAC1, and VPAC2 receptors were detected in the TG, suggesting they are all potential targets to treat migraine. These antibodies may be useful tools to help elucidate PACAP-responsive receptor expression in tissues. However, most antibodies exhibited limitations, requiring the use of multiple methodologies and the careful inclusion of controls.

Sex hormone-related polymorphisms in endometriosis and migraine: A narrative review.

Some evidence indicates endometriosis and migraine have a common genetic predisposition in sex-hormone genes, which could have important implications for the treatment of these two heterogenous conditions. To date, the genes responsibility remains unknown. Based on the biological hypothesis that polymorphisms of genes involved in sex-hormone pathways may influence estrogen levels and phenotypes of both disorders, we did a literature search for candidate sex-hormone genes and genes involved in the metabolism of estradiol. The aim was to review the evidence for shared sex-hormone-related polymorphisms between endometriosis and migraine and provide an exhaustive overview of the current literature. We included case-control studies investigating associations between candidate sex-hormone-related genes and the disorders endometriosis and migraine, respectively. Results showed three overlapping sex-hormone-associated polymorphisms in estrogen receptor genes that are associated with both conditions. To confirm possible associations with other sex-hormone genes, larger studies are needed.

[Mechanisms of liver-soothing and mind-regulating acupuncture mediating opioid receptor participated in the treatment of migraine].

OBJECTIVE: To observe the effect of "Shugan Tiaoshen"(liver-soothing and mind-regulating) acupuncture on behavior reactions, opioid receptor expressions in the anterior cingulate cortex tissue and inflammatory factors in the serum in migraine rats, in order to explore its mechanism underlying improvement of migraine. METHODS: In the first part of this study, forty male Wistar rats were randomized into control, model, routine acupuncture and "Shugan Tiaoshen" acupuncture groups (n=10/group), and in the second part, other 40 more male Wistar rats were randomized into low, medium and high dosage of blocker of µopioid receptor (OPRM）CTOP5 and PBS groups (n=10/group, for validating the involvement of opioid receptor in the effect of "Shugan Tiaoshen"). The migraine model was established by subcutaneous injection of glyceryl trinitrate. Routine acupuncture was applied to "Baihui" (GV20) and bilateral"Fengchi" (GB20), and "Shugan Tiaoshen" acupuncture applied to GV20, and bila-teral GB20, "Neiguan" (PC6) and "Taichong" (LR3), with the needles retained for 30 min. Behavior responses (head scratching, tail biting, cage climbing and number of going there and back) were scaled. Serum IL-1ß, IL-6 and TNF-α were detected by ELISA, and the expression levels of opioid receptor µ, δ and κ (OPRM, OPRD, OPRK) mRNAs and proteins in the anterior cingulate cortex were detected by fluorescence quantitative PCR and Western blot separately. In the second part of this study, CTOP solution (5µL at concentrations of 20µg/µL,10µg/µL and 5µg/µL) or PBS was injected into the bilateral rostral portions of anterior cingulate cortex 30 min before every "Shugan Tiaoshen" acupuncture intervention, followed by observing the behavioral changes and assaying the contents of serum IL-1ß, IL-6 and TNF-α. RESULTS: After modeling, the behavioral score, serum IL-1ß, IL-6 and TNF-α contents were significantly increased in the model group relevant to the control group (P<0.05), and the beha-vioral score had no significant difference among the model and two acupuncture groups before intervention (P>0.05). Whereas the expression levels of OPRM, OPRD and OPRK mRNAs and proteins had a slight increase in the model group (P>0.05). After the intervention, the behavioral score, serum IL-1ß, IL-6 and TNF-α contents were significantly decreased and the expression levels of OPRM, OPRD and OPRK mRNAs (2.150, 1.066 and 0.805 folds in the "Shugan Tiaoshen" group) and proteins (2.273, 0.901 and 0.893 folds in the "Shugan Tiaoshen" group) notably up-regulated in both "Shugan Tiaoshen" and routine acupuncture groups relevant to the model group (P<0.01, P<0.05), showing that the biggest up-regulation of mRNA expression was OPRM. Comparison between two acupuncture groups showed that the behavioral score, and serum IL-1ß, IL-6 and TNF-α contents were significantly lower, and the expression levels of OPRM, OPRD and OPRK mRNAs and proteins obviously higher in the "Shugan Tiaoshen" group than those in the routine acupuncture group (P<0.01,P<0.05). Results of the second part of this study showed that after injection of antagonist CTOP of OPRM, the therapeutic effect of "Shugan Tiaoshen" acupuncture was weakened in the reduction of behavioral score and serum IL-1ß, IL-6 and TNF-α contents, being minimal, moderate and maximum in the high, medium and low dose of antagonist relevant to PBS in sequence (P<0.05, P<0.01). CONCLUSION: "Shugan Tiaoshen" acupuncture can mitigate pain in migraine rats, which may be associated with its function in up-regulating the expressions of opioid receptors (especially OPRM), and in inhibiting inflammatory reaction in the anterior cingulate cortex.

Hemiplegic migraine type 2 with new mutation of the ATP1A2 gene in Japanese cases.

We analyzed the clinical symptoms of hemiplegic migraine (HM) and their relevance in four Japanese patients considered to have ATP1A2 mutations as a cause. Sequencing of ATP1A2 was performed using the Sanger method in 43 blood samples from clinically suspected patients with familial HM. Subsequently, algorithm analysis, allele frequency determination, and three-dimensional structure analysis of the recognized variants were performed, and the recognized variants were evaluated. We found four heterozygous missense mutations in ATP1A2 (Case 1: p.R51C; Case 2: p.R65L; Case 3: p.A269P; Case 4: p.D999H), three of which had not been reported to date. These four mutations may also affect the structure of the protein products, as assessed using a three-dimensional structural analysis. In all four cases, the clinical symptoms included visual, sensory, motor, and verbal symptoms and the frequency and duration of headache attacks varied. Additionally, oral administration of a combination of lomerizine hydrochloride and topiramate had a partial effect in three cases. We report four missense mutations in ATP1A2. This report will be useful for the future analysis of mutations and clinical types in Asians, as well as Westerners, with migraine.