Association of Polymorphisms within the Serotonin Receptor Genes 5-HTR1A, 5-HTR1B, 5-HTR2A and 5-HTR2C and Migraine Susceptibility in a Turkish Population

Sex-stratified association of variants in the serotonin 1A receptor gene with acute crisis pain among African American patients with sickle cell disease

Patients with sickle cell disease (SCD) experience pain in their daily lives. Both the acute and chronic pain phenotypes of this disease exhibit high variability, making pain management a challenge. The underlying reasons for the phenotypic variability are poorly understood. Given the importance of serotonergic neurotransmission in pain signaling, we aimed to explore the role of variants in the 5-HT1A receptor gene (HTR1A) on pain variability in SCD. Four variants (rs6449693, rs878567, rs6294, and rs10042486) in HTR1A were genotyped in a cohort of 131 African Americans with SCD. Acute and chronic pain were measured by the acute care utilization and the McGill Pain Questionnaire, respectively. Association analyses were performed for three genetic models (additive, dominant, and recessive). Three variants (rs6449693, rs6294, and rs10042486) in HTR1A showed significant association with crisis pain in both the additive and dominant models. Although the G allele of rs6449693 and the C allele of rs10042486 associated with lower acute crisis pain, the T allele of rs6294 associated with increased acute crisis pain. Sex-stratified analyses revealed that the associations of these three variants with acute pain were significant only in men, but not in women. Furthermore, the A allele rs878567 that did not reach statistical significance in the overall cohort showed a significant association with lower crisis pain in men. To our knowledge, as the first study to explore the role of HTR1A variants in sickle cell pain, we identified that four variants across the gene are associated with acute crisis pain in SCD in a sex-stratified manner.

Combined Methylphenidate and Selective Serotonin Reuptake Inhibitors in Adults With Attention-Deficit/Hyperactivity Disorder

Importance

Depression is a common comorbidity of adult attention-deficit/hyperactivity disorder (ADHD), and the combination of methylphenidate and selective serotonin reuptake inhibitors (SSRIs) is a frequently prescribed treatment. However, there is limited clinical evidence on the safety of this medication combination in adults with ADHD.

Objective

To evaluate the safety of administering a combination of SSRI and methylphenidate in adults with ADHD and comorbid depression.

Design, Setting, and Participants

This cohort study obtained data from a nationwide claims database in South Korea from January 2016 to February 2021. Participants were adults aged 18 years or older with a diagnosis of ADHD and depressive disorder who were prescribed methylphenidate. Comparisons of 4 groups who received prescriptions were conducted: (1) SSRI plus methylphenidate (hereafter, SSRI) group vs methylphenidate-only group and (2) methylphenidate plus fluoxetine (hereafter, fluoxetine) group vs methylphenidate plus escitalopram (hereafter, escitalopram) group (compared to find a preferable treatment option). Data analysis was conducted between July and December 2023.

Exposures

New users of the methylphenidate and SSRI combination among adults with both ADHD and depressive disorder.

Main Outcomes and Measures

A total of 17 primary and secondary outcomes, including neuropsychiatric and other events, were assessed, with respiratory tract infection used as a control outcome. Groups were matched at a 1:1 ratio using a propensity score to balance confounders. A Cox proportional hazards regression model was used to calculate hazard ratio (HRs) and 95% CIs. Subgroup analysis by sex and sensitivity analyses in varying epidemiologic settings were conducted.

Results

The study included 17 234 adults with ADHD (mean [SD] age at study entry, 29.4 [10.8] years; 9079 females [52.7%]). There was no difference in the risk of outcomes between the methylphenidate-only and SSRI groups, except for a lower risk of headache in the SSRI group (HR, 0.50; 95% CI, 0.24-0.99). In sensitivity analyses of fluoxetine vs escitalopram, the risk of hypertension (HR: 1:n matching, 0.26; 95% CI, 0.08-0.67) and hyperlipidemia (HR: 1:n matching, 0.23; 95% CI, 0.04-0.81) was lower in the fluoxetine group than in the escitalopram group.

Conclusions and Relevance

Results of this study revealed no significant increase in adverse event risk associated with use of SSRI plus methylphenidate vs methylphenidate alone in adults with ADHD and comorbid depression. Instead, the combination was associated with a lower risk of headache.

Revolutionizing migraine management: advances and challenges in CGRP-targeted therapies and their clinical implications

Migraine, a prevalent neurological disorder, affects approximately 14.1% of the global population and disproportionately impacts females. This debilitating condition significantly compromises quality of life, productivity, and incurs high healthcare costs, presenting a challenge not only to individuals but to societal structures as a whole. Despite advances in our understanding of migraine pathophysiology, treatment options remain limited, necessitating ongoing research into effective therapies. This review delves into the complexity of migraine management, examining the roles of genetic predisposition, environmental influences, personalized treatment approaches, comorbidities, efficacy and safety of existing acute and preventive treatments. It further explores the continuum between migraine and tension-type headaches and discusses the intricacies of treating various migraine subtypes, including those with and without aura. We emphasize the recent paradigm shift toward trigeminovascular activation and the release of vasoactive substances, such as calcitonin gene-related peptide (CGRP), which offer novel therapeutic targets. We assess groundbreaking clinical trials, pharmacokinetic and pharmacodynamic perspectives, safety, tolerability, and the real-world application of CGRP monoclonal antibodies and gepants. In the face of persisting treatment barriers such as misdiagnosis, medication overuse headaches, and limited access to specialist care, we discuss innovative CGRP-targeted strategies, the high cost and scarcity of long-term efficacy data, and suggest comprehensive solutions tailored to Turkiye and developing countries. The review offers strategic recommendations including the formulation of primary care guidelines, establishment of specialized outpatient clinics, updating physicians on novel treatments, enhancing global accessibility to advanced therapies, and fostering patient education. Emphasizing the importance of lifestyle modifications and holistic approaches, the review underscores the potential of mass media and patient groups in disseminating critical health information and shaping the future of migraine management.

Rizatriptan benzoate-loaded dissolving microneedle patch for management of acute migraine therapy

In this study, dissolving microneedles (MNs) using polyvinyl alcohol (PVA) and poly (1-vinylpyrrolidone-co-vinyl acetate) (P(VP-co-VA)) as matrix materials were developed for transdermal delivery of rizatriptan benzoate (RB) for acute migraine treatment. In-vitro permeation studies were conducted to assess the feasibility of the as-fabricated dissolving MNs to release RB. Drug skin penetration were tested by Franz diffusion cells, showing an increase of the transdermal flux compared to passive diffusion due to the as-fabricated dissolving MNs having a sufficient mechanical strength to penetrate the skin and form microchannels. The pharmacological study in vivo showed that RB-loaded dissolving MNs significantly alleviated migraine-related response by up-regulating the level of 5-hydroxytryptamine (5-HT) and down-regulating the levels of calcitonin gene-related peptide (CGRP) and substance P (SP). In conclusion, the RB-loaded dissolving MNs have advantages of safety, convenience, and high efficacy over conventional administrations, laying a foundation for the transdermal drug delivery system treatment for acute migraine.

Understanding the Biological Relationship between Migraine and Depression

Migraine is a highly prevalent neurological disorder. Among the risk factors identified, psychiatric comorbidities, such as depression, seem to play an important role in its onset and clinical course. Patients with migraine are 2.5 times more likely to develop a depressive disorder; this risk becomes even higher in patients suffering from chronic migraine or migraine with aura. This relationship is bidirectional, since depression also predicts an earlier/worse onset of migraine, increasing the risk of migraine chronicity and, consequently, requiring a higher healthcare expenditure compared to migraine alone. All these data suggest that migraine and depression may share overlapping biological mechanisms. Herein, this review explores this topic in further detail: firstly, by introducing the common epidemiological and risk factors for this comorbidity; secondly, by focusing on providing the cumulative evidence of common biological aspects, with a particular emphasis on the serotoninergic system, neuropeptides such as calcitonin-gene-related peptide (CGRP), pituitary adenylate cyclase-activating polypeptide (PACAP), substance P, neuropeptide Y and orexins, sexual hormones, and the immune system; lastly, by remarking on the future challenges required to elucidate the etiopathological mechanisms of migraine and depression and providing updated information regarding new key targets for the pharmacological treatment of these clinical entities.

Association between polymorphism rs6295 of HTR1A serotonin receptor gene and personality traits among athletes of combat sport

HTR1A (5-hydroxytryptamine receptor 1A) and its polymorphic variants are highly important for athletes in different aspects, allowing us to hypothesize their biological influences. Hence, to investigate at least part of the relationship mentioned in the case literature, it was decided to study the association of the selected HTR1A polymorphism with personality traits measured by the Temperament and Character Inventory (TCI). The participants consisted of 250 mixed martial arts (combat sport) athletes and 209 healthy male participants (control group). The personality traits were measured for the Revised Temperament and Character Inventory (TCI-R). Genetic material was isolated from whole blood collected from patients, and then all samples were genotyped using the real-time PCR method. Statistical analysis was performed using a 2 × 3 factorial ANOVA. The research revealed a statistically significant effect of a complex factor of rs6295 of the HTR1A serotonin receptor gene with combat sport/control and with Novelty Seeking (F2,453 = 6.126; p = 0.0024; η2 = 0.026) and Harm Avoidance (F2,453 = 3.709; p = 0.0252; η2 = 0.016). The presence of the HTR1A GG genotype (rs6295) was found to be associated with higher scores in self-management and lower scores in harm avoidance, indicating genetic predispositions in the strength group towards better results in combat sports.

Genetic overlap between temporomandibular disorders and primary headaches: A systematic review

Primary headache disorders (PHD), specifically migraine, are strongly associated with temporomandibular disorders (TMD), sharing some patterns of orofacial pain. Both disorders have significant genetic contributions already studied. PRISMA guidelines were followed to conduct this systematic review, which comprehensively summarize and discuss the genetic overlap between TMD and PHD to aid future research in potential therapy targets. This review included eight original articles published between 2015 and 2020, written in English and related to either TMD and/or PHD. The genes simultaneously assessed in PHD and TMD studies were COMT, MTHFR, and ESR1. COMT was proved to play a critical role in TMD pathogenesis, as all studies have concluded about its impact on the occurrence of the disease, although no association with PHD was found. No proof on the impact of MTHFR gene regulation on either TMD or PHD was found. The most robust results are concerning the ESR1 gene, which is present in the genetic profile of both clinical conditions. This novel systematic review highlights not only the need for a clear understanding of the role of ESR1 and COMT genes in pain pathogenesis, but it also evaluates their potential as a promising therapeutic target to treat both pathologies.

Exploring the pharmacological action mechanism of Ligusticum Chuanxiong-Piper Longum couplet medicines on the treatment of migraine based on network pharmacology

Objective: To study the mechanisms of the Ligusticum chuanxiong Hort.–Piper longum L. herbal pair (LPHP) in the treatment of migraine using network pharmacology.

Methods: The active constituents of LPHP and their targets were searched for and screened using the Chinese Medicine System Pharmacology Database. Genes related to migraine were searched on GeneCards, Online Mendelian Inheritance in Man and other databases. Cytoscape was used to construct and combine active component–target and disease–target networks. The core target was screened by network topology analysis, and the Metascape database was used for gene ontology analysis of key targets and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis to explore the molecular mechanisms in the treatment of migraine.

Results: A total of 28 active constituents of LPHP were obtained through database screening and literature review, and 60 cross-linking targets were obtained. The target sites were analysed using a protein–protein interaction network to obtain six target proteins with a greater degree of relevance. These were identified as the main targets for the treatment of hypertension, and these key targets were found to be associated with 20 signalling pathways, including neuroactive ligand–receptor interaction, the calcium signalling pathway, the cGMP–PKG signalling pathway, pathways in cancer and the cyclic adenosine 3′,5′-cyclic monophosphate (cAMP) signalling pathway.

Conclusion: This study reveals the molecular mechanism of LPHP in the treatment of migraine from the perspective of network pharmacology and provides a basis for further research and molecular mechanism research.

New Insights on Metabolic and Genetic Basis of Migraine: Novel Impact on Management and Therapeutical Approach

Migraine is a hereditary disease, usually one-sided, sometimes bilateral. It is characterized by moderate to severe pain, which worsens with physical activity and may be associated with nausea and vomiting, may be accompanied by photophobia and phonophobia. The disorder can occur at any time of the day and can last from 4 to 72 h, with and without aura. The pathogenic mechanism is unclear, but extensive preclinical and clinical studies are ongoing. According to electrophysiology and imaging studies, many brain areas are involved, such as cerebral cortex, thalamus, hypothalamus, and brainstem. The activation of the trigeminovascular system has a key role in the headache phase. There also appears to be a genetic basis behind the development of migraine. Numerous alterations have been identified, and in addition to the genetic cause, there is also a close association with the surrounding environment, as if on the one hand, the genetic alterations may be responsible for the onset of migraine, on the other, the environmental factors seem to be more strongly associated with exacerbations. This review is an analysis of neurophysiological mechanisms, neuropeptide activity, and genetic alterations that play a fundamental role in choosing the best therapeutic strategy. To date, the goal is to create a therapy that is as personalized as possible, and for this reason, steps forward have been made in the pharmacological field in order to identify new therapeutic strategies for both acute treatment and prophylaxis.

A Comprehensive Review on the Role of Genetic Factors in the Pathogenesis of Migraine

Migraine is a common neurovascular condition. This disorder has a complex genetic background. Several single-nucleotide polymorphisms (SNPs) or mutations within genes regulating glutamatergic neurotransmission, cortical excitability, ion channels, and solute carriers have been associated with polygenic and monogenic forms of migraine. SNPs within ACE, DBH, TRPM8, COMT, GABRQ, CALCA, TRPV1, and other genes have been reported to affect the risk of migraine or the associated clinical parameters. The distribution of some HLA alleles within the HLA-DRB1, HLA-DR2, HLA-B, and HLA-C regions have also been found to differ between migraineurs and healthy subjects. In addition, certain mitochondrial DNA changes and polymorphisms in this region have been shown to increase the risk of migraine. A few functional studies have investigated the molecular mechanisms contributing to these genetic factors in the development of migraine. Here we review studies evaluating the role of genetic polymorphisms and mRNA/miRNA dysregulation in migraine.

Schisandrin B exerts hypnotic effects in PCPA-treated rats by increasing hypothalamic 5-HT and γ-aminobutyric acid levels

Schisandrin B (SchB) is one of the primary active components of Schisandra chinensis (Turcz.) Baill., a traditional Chinese herb that has been used to treat insomnia for hundreds of years. Our previous studies revealed that SchB exerts sedative and hypnotic effects, increasing the content of γ-aminobutyric acid (GABA) and the expression of its receptors in the brain tissues of rats. 5-hydroxytryptamine (5-HT) is another important neurotransmitter involved in sleep regulation, although, to the best of our knowledge, there are no reports of its association with SchB. Therefore, the present study aimed to determine whether the hypnotic effect of SchB was partly due to alterations in the expression of 5-HT. The results indicated that SchB reduced sleep latency and increased sleep duration in parachlorophenylalanine (PCPA)-induced rats with insomnia by increasing 5-HT and 5-hydroxyindoleacetic acid, and upregulating the expression of the 5-HT receptor 1A in the hypothalamus. SchB also increased the ratio of GABA to glutamic acid and the activity of glutamic acid decarboxylase, decreased the activity of GABA transaminase, and upregulated the expression of GABA_A receptor α1 and GABA_A receptor γ2 in the rat hypothalamus. These results suggested that SchB improved PCPA-induced insomnia in rats, and its effects may be associated with the regulation of GABA and 5-HT levels in the hypothalamus.

Functional gene networks reveal distinct mechanisms segregating in migraine families

Migraine is the most common neurological disorder worldwide and it has been shown to have complex polygenic origins with a heritability of estimated 40-70%. Both common and rare genetic variants are believed to underlie the pathophysiology of the prevalent types of migraine, migraine with typical aura and migraine without aura. However, only common variants have been identified so far. Here we identify for the first time a gene module with rare mutations through a systems genetics approach integrating RNA sequencing data from brain and vascular tissues likely to be involved in migraine pathology in combination with whole genome sequencing of 117 migraine families. We found a gene module in the visual cortex, based on single nuclei RNA sequencing data, that had increased rare mutations in the migraine families and replicated this in a second independent cohort of 1930 patients. This module was mainly expressed by interneurons, pyramidal CA1, and pyramidal SS cells, and pathway analysis showed association with hormonal signalling (thyrotropin-releasing hormone receptor and oxytocin receptor signalling pathways), Alzheimer's disease pathway, serotonin receptor pathway and general heterotrimeric G-protein signalling pathways. Our results demonstrate that rare functional gene variants are strongly implicated in the pathophysiology of migraine. Furthermore, we anticipate that the results can be used to explain the critical mechanisms behind migraine and potentially improving the treatment regime for migraine patients.

Yohimbine as a Starting Point to Access Diverse Natural Product-Like Agents with Re-programmed Activities against Cancer-Relevant GPCR Targets

G protein-coupled receptors (GPCRs) constitute the largest protein superfamily in the human genome. GPCRs play key roles in mediating a wide variety of physiological events including proliferation and cancer metastasis. Given the major roles that GPCRs play in mediating cancer growth, they present promising targets for small molecule therapeutics. One of the principal goals of our lab is to identify complex natural products (NPs) suitable for ring distortion, or the dramatic altering of the inherently complex architectures of NPs, to rapidly generate an array of compounds with diverse molecular skeletal systems. The overarching goal of our ring distortion approach is to re-program the biological activity of select natural products and identify new compounds of importance to the treatment of disease, such as cancer. Described herein are the results from biological screens of diverse small molecules derived from the indole alkaloid yohimbine against a panel of GPCRs involved in various diseases. Several analogues displayed highly differential antagonistic activities across the GPCRs tested. We highlight the re-programmed profile of one analogue, Y7g, which exhibited selective antagonistic activities against AVPR2 (IC₅₀ = 459 nM) and OXTR (IC₅₀ = 1.16 µM). The activity profile of Y7g could correlate its HIF-dependent anti-cancer activity to its GPCR antagonism since these receptors are known to be upregulated in hypoxic cellular environments. Our findings demonstrate that the ring distortion of yohimbine can lead to the identification of new compounds capable of interacting with distinct cancer-relevant targets.

Antidepressants for Preventive Treatment of Migraine

PURPOSE OF REVIEW

This review describes the pharmacology of each antidepressant class as it applies to migraine prevention, summarizes the evidence base for each medication, and describes relevant side effects and clinical considerations. Use of antidepressants for migraine prevention in clinical practice is also discussed.

RECENT FINDINGS

Antidepressants are commonly used as migraine preventives. Amitriptyline has the best evidence for use in migraine prevention. Nortriptyline is an alternative in patients who may not tolerate amitriptyline. The sedating effect of TCAs can be beneficial for patients with comorbid insomnia. SNRIs including venlafaxine and duloxetine also have evidence for efficacy and may be the most effective treatments in patients with comorbid depression and migraine. SSRIs including fluoxetine are not effective for most patients. The side effect burden of antidepressants can be substantial. Patients should be particularly counseled about the possibility of a withdrawal effect from SNRIs. Antidepressants are an important option for preventive treatment of migraine. Further research on the efficacy and tolerability of SNRIs as migraine preventives is needed.

Development of an AmpliSeqTM Panel for Next-Generation Sequencing of a Set of Genetic Predictors of Persisting Pain

Background: Many gene variants modulate the individual perception of pain and possibly also its persistence. The limited selection of single functional variants is increasingly being replaced by analyses of the full coding and regulatory sequences of pain-relevant genes accessible by means of next generation sequencing (NGS).

Methods: An NGS panel was created for a set of 77 human genes selected following different lines of evidence supporting their role in persisting pain. To address the role of these candidate genes, we established a sequencing assay based on a custom AmpliSeq^TM panel to assess the exomic sequences in 72 subjects of Caucasian ethnicity. To identify the systems biology of the genes, the biological functions associated with these genes were assessed by means of a computational over-representation analysis.

Results: Sequencing generated a median of 2.85 ⋅ 10⁶ reads per run with a mean depth close to 200 reads, mean read length of 205 called bases and an average chip loading of 71%. A total of 3,185 genetic variants were called. A computational functional genomics analysis indicated that the proposed NGS gene panel covers biological processes identified previously as characterizing the functional genomics of persisting pain.

Conclusion: Results of the NGS assay suggested that the produced nucleotide sequences are comparable to those earned with the classical Sanger sequencing technique. The assay is applicable for small to large-scale experimental setups to target the accessing of information about any nucleotide within the addressed genes in a study cohort.

Current Prophylactic Medications for Migraine and Their Potential Mechanisms of Action

A relatively high number of different medications is currently used for migraine prevention in clinical practice. Although these compounds were initially developed for other indications and differ in their mechanisms of action, some general themes can be identified from the mechanisms at play. Efficacious preventive drugs seem to either suppress excitatory nervous signaling via sodium and/or calcium receptors, facilitate GABAergic inhibition, reduce neuronal sensitization, block cortical spreading depression and/or reduce circulating levels of CGRP. We here review such mechanisms for the different compounds.

Genetic and biochemical changes of the serotonergic system in migraine pathobiology

Migraine is a brain disorder characterized by a piercing headache which affects one side of the head, located mainly at the temples and in the area around the eye. Migraine imparts substantial suffering to the family in addition to the sufferer, particularly as it affects three times more women than men and is most prevalent between the ages of 25 and 45, the years of child rearing. Migraine typically occurs in individuals with a genetic predisposition and is aggravated by specific environmental triggers. Attempts to study the biochemistry of migraine began as early as the 1960s and were primarily directed at serotonin metabolism after an increase of 5-hydroxyindoleacetic acid (5-HIAA), the main metabolite of serotonin was observed in urine of migraineurs. Genetic and biochemical studies have primarily focused on the neurotransmitter serotonin, considering receptor binding, transport and synthesis of serotonin and have investigated serotonergic mediators including enzymes, receptors as well as intermediary metabolites. These studies have been mainly assayed in blood, CSF and urine as the most accessible fluids. More recently PET imaging technology integrated with a metabolomics and a systems biology platform are being applied to study serotonergic biology. The general trend observed is that migraine patients have alterations of neurotransmitter metabolism detected in biological fluids with different biochemistry from controls, however the interpretation of the biological significance of these peripheral changes is unresolved. In this review we present the biology of the serotonergic system and metabolic routes for serotonin and discuss results of biochemical studies with regard to alterations in serotonin in brain, cerebrospinal fluid, saliva, platelets, plasma and urine of migraine patients.