The Epigenetics of Migraine

The association between migraine and gut microbiota: a systematic review

INTRODUCTION

Recent studies suggest a link between gut microbiota and neurological diseases, implicating the microbiome's role in neurological health. However, the specific alterations in the microbiome associated with migraine remain underexplored. This study aims to systematically review the existing literature to determine whether migraine patients are associated with changes in gut microbiota composition.

METHODS

A systematic review was conducted in accordance with the PRISMA statement. We included original empirical studies investigating the microbiome in migraine patients. Data extracted included study design, participant demographics, microbiome differences at various taxonomic levels, and measures of microbial diversity (alpha and beta diversity). The search and selection process involved four independent reviewers who assessed abstracts and full texts to ensure eligibility. The gut microbiota was evaluated using relative abundance and diversity indices.

RESULTS

Six studies, encompassing various regions including China, Korea, and Italy, were included in the analysis. The results indicated significant differences in gut microbiota between migraine patients and controls. Key findings include a reduction in Faecalibacterium, a genus known for its anti-inflammatory properties, in migraine patients, including those with chronic migraine. Conversely, Veillonella exhibited elevated abundance compared to controls. Other taxa, such as Prevotella and Parabacteroides, showed variable associations with migraine across different studies, suggesting a dysbiotic gut environment in migraine patients.

CONCLUSION

This review highlights that migraines are associated with specific alterations in gut microbiota, including decreased microbial diversity and changes in the abundance of key taxa. These findings suggest that gut microbiota dysbiosis may play a role in migraine pathophysiology. Further research is needed to explore the potential causal relationships and therapeutic implications, particularly targeting the microbiome in migraine management.

Association between serum folate levels and migraine or severe headaches: A nationwide cross-sectional study

Migraine and severe headaches are common neurological disorders with significant societal impact. Previous research indicates a potential link between serum folate levels and migraine occurrence, yet there is a lack of sufficient relevant studies and more are required. This study aimed to determine the association between a severe headache or migraine and serum folate levels in large populations. Using data from the National Health and Nutrition Examination Survey, we conducted a cross-sectional study. Using multivariable logistic regression models, we investigated the association between serum folate and severe headache or migraine. In a subsequent subgroup analysis, several confounding factors were also explored to investigate the association between migraine and serum folate. A total of 13,351 individuals participated in the study, with 2742 reporting severe headache or migraine in the previous 3 months. Serum folate was negatively associated with severe headache or migraine (odds ratio [OR] = 0.5, 95% confidence interval [CI] = 0.28-0.89, P = .018). The stratified analysis revealed this association persisted among female (OR = 0.38, 95% CI = 0.18-0.82, P < .001), individuals aged 20 to 50 years (OR = 0.53, 95% CI = 0.28-0.99, P < .001), and non-Hispanic White participants (OR = 0.38, 95% CI = 0.17-0.87, P < .001). We found that greater levels of serum folate were significantly related to a decreased likelihood of migraine onset, especially among women, young and middle-aged populations, and non-Hispanic White participants. Further research is required to validate and expand upon our results.

Research trends and hotspots in clinical trials of migraine in the past 20 years: bibliometric analysis

Background

Migraine is a widespread, recurrent primary headache disorder primarily characterized by severe pulsatile headache, typically on one or both sides. It is often accompanied by nausea, vomiting, and hypersensitivity to sound and light. Despite the availability of multiple drugs for migraine management, the condition often becomes chronic due to untimely or irrational drug use, significantly distressing patients and increasing the burden on families and society. Over the past two decades, numerous clinical studies on migraine have been published. This study aimed to provide a comprehensive summary of the current status and trends of migraine clinical trials through bibliometric analysis.

Methods

We used visual network tools such as CiteSpace and VOSviewer to perform a knowledge graph analysis of publications related to migraine clinical trials extracted from the WoSCC.

Results

This study analyzed 1,129 articles published in 389 journals from 61 countries. The number of publications on migraine clinical trials has steadily increased from 2004 to 2023. The United States and Albert Einstein College of Medicine are the leading countries and institutions in this field, respectively. Richard B. Lipton is the most prolific author, making significant contributions to the research. The journal Headache has the highest number of publications and citations in this area. Keywords such as "efficacy," "RCT," "CGRP," "prophylaxis," "disability," "depression," "questionnaire," and "real-world effectiveness" received significant attention.

Conclusion

This study identified reliable research hotspots and provided directions for clinicians. The treatment of migraine continues to be challenging. Future trends may include continued growth in migraine classification, risk factor analysis, and comorbidity studies. Research on CGRP and epigenetics will advance the progress of precision medicine in the migraine field.

Bioinformatic Analysis from a Descriptive Profile of miRNAs in Chronic Migraine

Chronic migraines have been described chiefly only from a clinical perspective. However, searching for reliable molecular markers has allowed for the discovery of the expression of different genes mainly associated with inflammation, neuro-vascularization, and pain-related pathways. The interest in microRNAs (miRs) that can regulate the expression of these genes has gained significant relevance since multiple miRs could play a key role in regulating these events. In this study, miRs were searched in samples from patients with chronic migraine, and the inclusion criteria were carefully reviewed. Different bioinformatic tools, such as miRbase, targetscan, miRPath, tissue atlas, and miR2Disease, were used to analyze the samples. Our findings revealed that some of the miRs were expressed more (miR-197, miR-101, miR-92a, miR-375, and miR-146b) and less (miR-133a/b, miR-134, miR-195, and miR-340) than others. We concluded that, during chronic migraine, common pathways, such as inflammation, vascularization, neurodevelopment, nociceptive pain, and pharmacological resistance, were associated with this disease.

Models for depression recognition and efficacy assessment based on clinical and sequencing data

Major depression is a complex psychiatric disorder that includes genetic, neurological, and cognitive factors. Early detection and intervention can prevent progression, and help select the best treatment. Traditional clinical diagnosis tends to be subjective and misdiagnosed. Based on this, this study leverages clinical scale assessments and sequencing data to construct disease prediction models. Firstly, data undergoes preprocessing involving normalization and other requisite procedures. Feature engineering is then applied to curate subsets of features, culminating in the construction of a model through the implementation of machine learning and deep learning algorithms. In this study, 18 features with significant differences between patients and healthy controls were selected. The depression recognition model was constructed by deep learning with an accuracy of 87.26 % and an AUC of 91.56 %, which can effectively distinguish patients with depression from healthy controls. In addition, 33 features selected by recursive feature elimination method were used to construct a prognostic effect model of patients after 2 weeks of treatment, with an accuracy of 75.94 % and an AUC of 83.33 %. The results show that the deep learning algorithm based on clinical and sequencing data has good accuracy and provides an objective and accurate method for the diagnosis and pharmacodynamic prediction of depression. Furthermore, the selected differential features can serve as candidate biomarkers to provide valuable clues for diagnosis and efficacy prediction.

MicroRNA profiling in women with migraine: effects of CGRP-targeting treatment

BACKGROUND

Migraine lacks biomarkers that can trace the biological pathways of the disease and predict the effectiveness of treatments. Monoclonal antibodies targeting calcitonin gene-related peptide pathway - including erenumab - offer the opportunity of investigating potential migraine biomarkers due to their specific mechanism of action in preventing both episodic (EM) and chronic (CM) migraine. Our study aims at evaluating the expression levels of circulating microRNAs (miRNAs) according to migraine type, before and after treatment with erenumab and based on treatment response, in order to identify miRNAs with potential role as epigenetic biomarkers.

METHODS

The study included women aged 25-50 years with EM or CM treated with erenumab according to clinical indications. MiRNAs expression levels were assessed before (baseline) and after a 16-week treatment with erenumab, 140 mg every four weeks (post-treatment). An extensive miRNAs profiling was performed by qRT-PCR in small, pooled groups of ≤ 8 women each, classified according to migraine frequency (EM and CM) and the degree of response to erenumab. The expression levels of selected miRNAs were also validated using single miRNA assays in each woman with EM and CM.

RESULTS

During the study, 36 women with migraine (19 with EM and 17 with CM) out of 40 who were initially screened, performed the assessment of miRNA expression at baseline and post-treatment, Erenumab treatment significantly improved migraine burden in both EM and CM. MiRNA profiling revealed differential expression levels of a wide set of miRNAs (hsa-let-7d-3p, hsa-miR-106b-3p, hsa-miR-122-5p, hsa-miR-143-3p, hsa-miR-144-3p, hsa-miR-16-5p, hsa-miR-181a-5p, hsa-miR-221-3p, hsa-miR-25-3p, hsa-miR-29b-2-5p, hsa-miR-326, miR-363-3p, hsa-miR-424-5p, hsa-miR-485-3p, hsa-miR-532-5p, hsa-miR-543, hsa-miR-629-5p, hsa-miR-660-5p, hsa-miR-92a-3p) depending on treatment response. Among them, single miRNA assays confirmed the progressive decrease of hsa-miR-143-3p expression levels in relation to increasing response to erenumab in women with EM (7 with low, 6 with medium, and 6 with high response; p = 0.02). Additionally, single assays showed higher hsa-miR-34a-5p and hsa-miR-382-5p expression levels at baseline in women with CM compared with those with EM (p = 0.0002 and p = 0.0007, respectively), as well as their expression level decrease in women with CM from baseline to follow-up (p = 0.04 and p = 0.02, respectively).

CONCLUSIONS

Our study suggests that targeting the CGRP pathway in migraine changes the expression levels of certain miRNAs. These miRNA levels are linked to the levels of response to CGRP receptor blockage. Future research challenges include assigning specific functions to the modulated miRNAs to unravel pathways modulated by the disease and the treatment.

TRIAL REGISTRATION

The study was registered in clinicaltrials.gov with code NCT04659226 and in the Novartis database with code CAMG334AIT05T.

Influences of Genetic and Environmental Factors on Chronic Migraine: A Narrative Review

PURPOSE OF REVIEW

In this narrative review, we aim to summarize recent insights into the complex interplay between environmental and genetic factors affecting the etiology, development, and progression of chronic migraine (CM).

RECENT FINDINGS

Environmental factors such as stress, sleep dysfunction, fasting, hormonal changes, weather patterns, dietary compounds, and sensory stimuli are critical triggers that can contribute to the evolution of episodic migraine into CM. These triggers are particularly influential in genetically predisposed individuals. Concurrently, genome-wide association studies (GWAS) have revealed over 100 genetic loci linked to migraine, emphasizing a significant genetic basis for migraine susceptibility. In CM, environmental and genetic factors are of equal importance and contribute to the pathophysiology of the condition. Understanding the bidirectional interactions between these elements is crucial for advancing therapeutic approaches and preventive strategies. This balanced perspective encourages continued research into the complex gene-environment nexus to improve our understanding and management of CM.

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)-1β 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.

A case-control comparison of acute-phase peripheral blood gene expression in participants diagnosed with minor ischaemic stroke or stroke mimics

BACKGROUND

Past studies suggest that there are changes in peripheral blood cell gene expression in response to ischaemic stroke; however, the specific changes which occur during the acute phase are poorly characterised. The current study aimed to identify peripheral blood cell genes specifically associated with the early response to ischaemic stroke using whole blood samples collected from participants diagnosed with ischaemic stroke (n = 29) or stroke mimics (n = 27) following emergency presentation to hospital. Long non-coding RNA (lncRNA), mRNA and micro-RNA (miRNA) abundance was measured by RNA-seq, and the consensusDE package was used to identify genes which were differentially expressed between groups. A sensitivity analysis excluding two participants with metastatic disease was also conducted.

RESULTS

The mean time from symptom onset to blood collection was 2.6 h. Most strokes were mild (median NIH stroke scale score 2.0). Ten mRNAs (all down-regulated in samples provided by patients experiencing ischaemic stroke) and 30 miRNAs (14 over-expressed and 16 under-expressed in participants with ischaemic stroke) were significantly different between groups in the whole cohort and sensitivity analyses. No significant over-representation of gene ontology categories by the differentially expressed genes was observed. Random forest analysis suggested a panel of differentially expressed genes (ADGRG7 and miRNAs 96, 532, 6766, 6798 and 6804) as potential ischaemic stroke biomarkers, although modelling analyses demonstrated that these genes had poor diagnostic performance.

CONCLUSIONS

This study provides evidence suggesting that the early response to minor ischaemic stroke is predominantly reflected by changes in the expression of miRNAs in peripheral blood cells. Further work in independent cohorts particularly in patients with more severe stroke is needed to validate these findings and investigate their clinical relevance.

Intelligent Digital Twins for Personalized Migraine Care

Intelligent digital twins closely resemble their real-life counterparts. In health and medical care, they enable the real-time monitoring of patients, whereby large amounts of data can be collected to produce actionable information. These powerful tools are constructed with the aid of artificial intelligence, machine learning, and deep learning; the Internet of Things; and cloud computing to collect a diverse range of digital data (e.g., from digital patient journals, wearable sensors, and digitized monitoring equipment or processes), which can provide information on the health conditions and therapeutic responses of their physical twins. Intelligent digital twins can enable data-driven clinical decision making and advance the realization of personalized care. Migraines are a highly prevalent and complex neurological disorder affecting people of all ages, genders, and geographical locations. It is ranked among the top disabling diseases, with substantial negative personal and societal impacts, but the current treatment strategies are suboptimal. Personalized care for migraines has been suggested to optimize their treatment. The implementation of intelligent digital twins for migraine care can theoretically be beneficial in supporting patient-centric care management. It is also expected that the implementation of intelligent digital twins will reduce costs in the long run and enhance treatment effectiveness. This study briefly reviews the concept of digital twins and the available literature on digital twins for health disorders such as neurological diseases. Based on these, the potential construction and utility of digital twins for migraines will then be presented. The potential and challenges when implementing intelligent digital twins for the future management of migraines are also discussed.