TRESK channel activation ameliorates migraine-like pain via modulation of CGRP release from the trigeminovascular system and meningeal mast cells in experimental migraine models.

AIMS: Accumulating evidence indicates the involvement of TRESK potassium channels in migraine, however, effects of TRESK activation on migraine-related mechanisms remain unclear. We explored effects of TRESK channel modulation on migraine-related behavioral and molecular markers in in-vivo and ex-vivo rat models of migraine. MAIN METHODS: The selective TRESK activator cloxyquin at different doses, the TRESK inhibitor A2764, and the migraine drug sumatriptan were tested alone or in different combinations in nitroglycerin (NTG)-induced in-vivo model, and in ex-vivo meningeal, trigeminal ganglion and brainstem preparations in which CGRP release was induced by capsaicin. Mechanical allodynia, CGRP and c-fos levels in trigeminovascular structures and meningeal mast cells were evaluated. KEY FINDINGS: Cloxyquin attenuated NTG-induced mechanical allodynia, brainstem c-fos and CGRP levels, trigeminal ganglion CGRP levels and meningeal mast cell degranulation and number, in-vivo. It also diminished capsaicin-induced CGRP release from ex-vivo meningeal, trigeminal ganglion and brainstem preparations. Specific TRESK inhibitor A2764 abolished all effects of cloxyquin in in-vivo and ex-vivo. Combining cloxyquin and sumatriptan exerted a synergistic effect ex-vivo, but not in-vivo. SIGNIFICANCE: Our findings provide the experimental evidence for the anti-migraine effect of TRESK activation in migraine-like conditions. The modulation of TRESK channels may therefore be an attractive alternative strategy to relieve migraine pain.

Pediatric migraine is characterized by traits of ecological and metabolic dysbiosis and inflammation.

BACKGROUND: Recently, there has been increasing interest in the possible role of the gut microbiota (GM) in the onset of migraine. Our aim was to verify whether bacterial populations associated with intestinal dysbiosis are found in pediatric patients with migraine. We looked for which metabolic pathways, these bacteria were involved and whether they might be associated with gut inflammation and increased intestinal permeability. METHODS: Patients aged between 6 and 17 years were recruited. The GM profiling was performed by the 16S rRNA metataxonomics of faecal samples from 98 patients with migraine and 98 healthy subjects. Alpha and beta diversity analyses and multivariate and univariate analyses were applied to compare the gut microbiota profiles between the two group. To predict functional metabolic pathways, we used phylogenetic analysis of communities. The level of indican in urine was analyzed to investigate the presence of metabolic dysbiosis. To assess gut inflammation, increased intestinal permeability and the mucosal immune activation, we measured the plasmatic levels of lipopolysaccharide, occludin and IgA, respectively. RESULTS: The α-diversity analysis revealed a significant increase of bacterial richness in the migraine group. The ß-diversity analysis showed significant differences between the two groups indicating gut dysbiosis in patients with migraine. Thirty-seven metabolic pathways were increased in the migraine group, which includes changes in tryptophan and phenylalanine metabolism. The presence of metabolic dysbiosis was confirmed by the increased level of indican in urine. Increased levels of plasmatic occludin and IgA indicated the presence of intestinal permeability and mucosal immune activation. The plasmatic LPS levels showed a low intestinal inflammation in patients with migraine. CONCLUSIONS: Pediatric patients with migraine present GM profiles different from healthy subjects, associated with metabolic pathways important in migraine.

MetaCGRP is a high-precision meta-model for large-scale identification of CGRP inhibitors using multi-view information.

Migraine is considered one of the debilitating primary headache conditions with an estimated worldwide occurrence of approximately 14-15%, contributing highly to factors responsible for global disability. Calcitonin gene-related peptide (CGRP) is a neuropeptide that plays a crucial role in the pathophysiology of migraines and thus, its inhibition can help relieve migraine symptoms. However, conventional process of CGRP drug development has been laborious and time-consuming with incurred costs exceeding one billion dollars. On the other hand, machine learning (ML)-based approaches that are capable of accurately identifying CGRP inhibitors could greatly facilitate in expediting the discovery of novel CGRP drugs. Therefore, this study proposes a novel and high-accuracy meta-model, namely MetaCGRP, that can precisely identify CGRP inhibitors. To the best of our knowledge, MetaCGRP is the first SMILES-based approach that has been developed to identify CGRP inhibitors without the use of 3D structural information. In brief, we initially employed different molecular representation methods coupled with popular ML algorithms to construct a pool of baseline models. Then, all baseline models were optimized and used to generate multi-view features. Finally, we employed the feature selection method to optimize the multi-view features and determine the best feature subset to enable the construction of the meta-model. Both cross-validation and independent tests indicated that MetaCGRP clearly outperforms several conventional ML classifiers, with accuracies of 0.898 and 0.799 on the training and independent test datasets, respectively. In addition, MetaCGRP in conjunction with molecular docking was utilized to identify five potential natural product candidates from Thai herbal pharmacopoeia and analyze their binding affinity and interactions to CGRP. To facilitate community-wide efforts in expediting the discovery of novel CGRP inhibitors, a user-friendly web server for MetaCGRP is freely available at https://pmlabqsar.pythonanywhere.com/MetaCGRP .

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.

Neuron-glia crosstalk and inflammatory mediators in migraine pathophysiology.

Migraine is a complex neurological disorder with neuroinflammation playing a crucial role in its pathogenesis. This review provides an overview of the neuroinflammation mechanisms in migraine, focusing on both cellular and molecular aspects. At the cellular level, we examine the role of glial cells, including astrocytes, microglia, oligodendrocytes in the central nervous system, and Schwann cells and satellite glial cells in the peripheral nervous system. On the molecular level, we explore the signaling pathways, including IL-1ß, TNF-α, IL-6, and non-coding RNAs, that mediate cell interactions or independent actions. Some of the molecular signaling pathways mentioned, such as TNF-α and IL-1ß, have been investigated as druggable targets. Recent advancements, such as [11C] PBR28-targeted imaging for visualizing astrocyte activation and single-cell sequencing for exploring cellular heterogeneity, represent breakthroughs in understanding the mechanisms of neuroinflammation in migraine. By considering factors for personalized treatments, estrogen and TRPM8 emerge as promising therapeutic targets regarding sexual dimorphism. These advancements may help bridge the gap between preclinical findings and clinical applications, ultimately leading to more precise and personalized options for migraine patients.

Molecular and Cellular Neurobiology of Spreading Depolarization/Depression and Migraine: A Narrative Review.

Migraine is a prevalent neurological disorder, particularly among individuals aged 20-50 years, with significant social and economic impacts. Despite its high prevalence, the pathogenesis of migraine remains unclear. In this review, we provide a comprehensive overview of cortical spreading depolarization/depression (CSD) and its close association with migraine aura, focusing on its role in understanding migraine pathogenesis and therapeutic interventions. We discuss historical studies that have demonstrated the role of CSD in the visual phenomenon of migraine aura, along with modern imaging techniques confirming its propagation across the occipital cortex. Animal studies are examined to indicate that CSD is not exclusive to migraines; it also occurs in other neurological conditions. At the cellular level, we review how CSD is characterized by ionic changes and excitotoxicity, leading to neuronal and glial responses. We explore how CSD activates the trigeminal nervous system and upregulates the expression of calcitonin gene-related peptides (CGRP), thereby contributing to migraine pain. Factors such as genetics, obesity, and environmental conditions that influence the CSD threshold are discussed, suggesting potential therapeutic targets. Current treatments for migraine, including prophylactic agents and CGRP-targeting drugs, are evaluated in the context of their expected effects on suppressing CSD activity. Additionally, we highlight emerging therapies such as intranasal insulin-like growth factor 1 and vagus nerve stimulation, which have shown promise in reducing CSD susceptibility and frequency. By elucidating the molecular and cellular mechanisms of CSD, this review aims to enhance the understanding of migraine pathogenesis and support the development of targeted therapeutic strategies.

Mechanisms of GTN-induced migraine: Role of NOS isoforms, sGC and peroxynitrite in a migraine relevant mouse model.

BACKGROUND: Migraine research has highlighted the pivotal role of nitric oxide (NO) in migraine pathophysiology. Nitric oxide donors such as glyceryl trinitrate (GTN) induce migraine attacks in humans, whereas spontaneous migraine attacks can be aborted by inhibiting NO production. The present study aimed to investigate how GTN triggers migraine through its three nitric oxide synthase (NOS) isoforms (neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS)) via a suspected feed-forward phenomenon. METHODS: Migraine-relevant hypersensitivity was induced by repeated injection of GTN in an in vivo mouse model. Cutaneous tactile sensitivity was assessed using von Frey filaments. Signaling pathways involved in this model were dissected using non-selective and selective NOS inhibitors, knockout mice lacking eNOS or nNOS and their wild-type control mice. Also, we tested a soluble guanylate cyclase inhibitor and a peroxynitrite decomposition catalyst (Ntotal = 312). RESULTS: Non-selective NOS inhibition blocked GTN-induced hypersensitivity. This response was partially associated with iNOS, and potentially nNOS and eNOS conjointly. Furthermore, we found that the GTN response was largely dependent on the generation of peroxynitrite and partly soluble guanylate cyclase. CONCLUSIONS: Migraine-relevant hypersensitivity induced by GTN is mediated by a possible feed-forward phenomenon of NO driven mainly by iNOS but with contributions from other isoforms. The involvement of peroxynitrite adds to the notion that oxidative stress reactions are also involved.

Alpha-asarone alleviates cutaneous hyperalgesia by inhibiting hyperexcitability and neurogenic inflammation via TLR4/NF-κB/NLRP3 signaling pathway in a female chronic migraine rat model.

Migraine is a highly prevalent neurological disorder. Alpha-asarone (ASA), a major active component found in Acorus tatarinowii, plays a crucial role in analgesia and anti-inflammation for neuropathic pain. This study aimed to assess the efficacy of ASA against migraine and elucidate its potential mechanisms using a well-established inflammatory soup (IS) migraine female rat model. Mechanical pain thresholds were assessed daily before IS infusion, followed by post-infusion administration of ASA. Subsequently, spontaneous locomotor activities, exploratory behavior, short-term spatial memory, and photophobia were blindly evaluated after the final drug administration. The rats were then sacrificed for investigation into the underlying mechanisms of action. Network pharmacology was also employed to predict potential targets and pathways of ASA against migraine. The anti-inflammatory activity of ASA and pathway-related proteins were examined in BV2 cells stimulated with lipopolysaccharides (LPS). The results demonstrated that ASA ameliorated cutaneous hyperalgesia and photophobia while improving spatial memory and increasing exploratory behavior in IS rats. ASA attenuated central sensitization-related indicators and excessive glutamate levels while enhancing GABA synthesis. ASA rescued neuronal loss in the cortex and hippocampus of IS rats. Notably, the ability of ASA to improve spatial memory performance in the Y maze test was not observed with sumatriptan, a first-line treatment drug, suggesting the potential involvement of the TLR4 pathway. Moreover, ASA suppressed microglial activation, reduced pro-inflammatory factors, and downregulated TLR4, MyD88, p-NF-κB/NF-κB, NLRP3, caspase-1, IL-1ß, and IL-18. Overall, ASA demonstrated its potential to alleviate hyperalgesia and improve behavioral performance in migraine rats by inhibiting hyperexcitability and microglia-related inflammation.

1H-MRS reveals abnormal energy metabolism and excitatory-inhibitory imbalance in a chronic migraine-like state induced by nitroglycerin in mice.

BACKGROUND: Chronic migraine is closely related to the dysregulation of neurochemical substances in the brain, with metabolic imbalance being one of the proposed causes of chronic migraine. This study aims to evaluate the metabolic changes between energy metabolism and excitatory and inhibitory neurotransmitters in key brain regions of mice with chronic migraine-like state and to uncover the dysfunctional pathways of migraine. METHODS: A chronic migraine-like state mouse model was established by repeated administration of nitroglycerin (NTG). We used von Frey filaments to assess the mechanical thresholds of the hind paw and periorbital in wild-type and familial hemiplegic migraine type 2 mice. After the experiments, tissue was collected from five brain regions: the somatosensory cortex (SSP), hippocampus, thalamus (TH), hypothalamus, and the spinal trigeminal nucleus caudalis (TNC). Proton magnetic resonance spectroscopy (1H-MRS) was employed to study the changes in brain metabolites associated with migraine, aiming to explore the mechanisms underlying metabolic imbalance in chronic migraine-like state. RESULTS: In NTG-induced chronic migraine-like state model, we observed a significant reduction in energy metabolism during central sensitization, an increase in excitatory neurotransmitters such as glutamate, and a tendency for inhibitory neurotransmitters like GABA to decrease. The TNC and thalamus were the most affected regions. Furthermore, the consistency of N-acetylaspartate levels highlighted the importance of the TNC-TH-SSP pathway in the ascending nociceptive transmission of migraine. CONCLUSION: Abnormal energy metabolism and neurotransmitter imbalance in the brain region of NTG-induced chronic migraine-like state model are crucial mechanisms contributing to the chronicity of migraine.

Targeting IGF1/IGF1r signaling relieve pain and autophagic dysfunction in NTG-induced chronic migraine model of mice.

BACKGROUND: Chronic migraine is a severe and common neurological disorder, yet its precise physiological mechanisms remain unclear. The IGF1/IGF1r signaling pathway plays a crucial role in pain modulation. Studies have shown that IGF1, by binding to its receptor IGF1r, activates a series of downstream signaling cascades involved in neuronal survival, proliferation, autophagy and functional regulation. The activation of these pathways can influence nociceptive transmission. Furthermore, alterations in IGF1/IGF1r signaling are closely associated with the development of various chronic pain conditions. Therefore, understanding the specific mechanisms by which this pathway contributes to pain is of significant importance for the development of novel pain treatment strategies. In this study, we investigated the role of IGF1/IGF1r and its potential mechanisms in a mouse model of chronic migraine. METHODS: Chronic migraine was induced in mice by repeated intraperitoneal injections of nitroglycerin. Mechanical and thermal hypersensitivity responses were assessed using Von Frey filaments and radiant heat, respectively. To determine the role of IGF1/IGF1r in chronic migraine (CM), we examined the effects of the IGF1 receptor antagonist ppp (Picropodophyllin) on pain behaviors and the expression of calcitonin gene-related peptide (CGRP) and c-Fos. RESULT: In the nitroglycerin-induced chronic migraine model in mice, neuronal secretion of IGF1 is elevated within the trigeminal nucleus caudalis (TNC). Increased phosphorylation of the IGF1 receptor occurs, predominantly co-localizing with neurons. Treatment with ppp alleviated basal mechanical hypersensitivity and acute mechanical allodynia. Furthermore, ppp ameliorated autophagic dysfunction and reduced the expression of CGRP and c-Fos. CONCLUSION: Our findings demonstrate that in the chronic migraine (CM) model in mice, there is a significant increase in IGF1 expression in the TNC region. This upregulation of IGF1 leads to enhanced phosphorylation of IGF1 receptors on neurons. Targeting and inhibiting this signaling pathway may offer potential preventive strategies for mitigating the progression of chronic migraine.

A male-specific mechanism of meningeal nociceptor sensitization promoting migraine headache.

BACKGROUND: We wished to explore possible sexual dimorphism in mechanisms sensitizing or activating meningeal nociceptors that can promote the headache phase of migraine. METHODS: Male and female C57BL6J mice received either supradural orexin B and an inflammatory mediator cocktail (IM) with migraine-like pain behaviors and photophobia recorded. Expression of orexin 2 receptor (OX2R) in trigeminal ganglion (TG) and phosphorylated extracellular signal-regulated kinases (ERK) levels in trigeminal nucleus caudalis (TNC) were evaluated. Orexin B-induced excitability of TG cells was assessed with patch-clamp electrophysiology. Intranasal delivery of CRISPR/Cas9 plasmids was used to edit the expression of OX2R in the TG. RESULTS: Supradural orexin B induced migraine-like pain behaviors, photophobia and increased TNC ERK phosphorylation exclusively in males. Blockade of orexin signaling with supradural suvorexant, a dual orexin receptor antagonist, prevented, but did not reverse, migraine-like pain in males induced by supradural IM cocktail. OX2R expression was higher in male TG and orexin B increased TG neuron excitability in males. Intranasal OX2R CRISPR/Cas9 reduced TG receptor expression and orexin B-induced TNC ERK phosphorylation and prevented migraine-like pain induced by supradural orexin B in males. CONCLUSIONS: Our studies reveal a male-specific mechanism of TG nociceptor sensitization and migraine-like pain behavior mediated by orexin B/OX2R signaling. Sexually dimorphic mechanisms of trigeminal nociceptor sensitization and activation offer opportunities to improve patient outcomes by considering patient sex and may influence clinical trial design and interpretation.

Higher sodium in older individuals or after stroke/reperfusion, but not in migraine or Alzheimer's disease - a study in different preclinical models.

Sodium serves as one of the primary cations in the central nervous system, playing a crucial role in maintaining normal brain function. In this study, we investigated alterations in sodium concentrations in the brain and/or cerebrospinal fluid across multiple models, including an aging model, a stroke model, a nitroglycerin (NTG)-induced rat migraine model, a familial hemiplegic migraine type 2 (FHM2) mouse model, and a transgenic mouse model of Alzheimer's disease (AD). Our results reveal that older rats exhibited higher sodium concentrations in cerebrospinal fluid (CSF), plasma, and various brain regions compared to their younger counterparts. Additionally, findings from the stroke model demonstrated a significant increase in sodium in the ischemic/reperfused region, accompanied by a decrease in potassium and an elevated sodium/potassium ratio. However, we did not detect significant changes in sodium in the NTG-induced rat migraine model or the FHM2 mouse model. Furthermore, AD transgenic mice showed no significant differences in sodium levels compared to wild-type mice in CSF, plasma, or the hippocampus. These results underscore the nuanced regulation of sodium homeostasis in various neurological conditions and aging, providing valuable insights into potential mechanisms underlying these alterations.

Effects of ß-sitosterol on anxiety in migraine-induced rats: The role of oxidative/nitrosative stress and mitochondrial function.

AIMS: Anxiety often coexists with migraine, and both conditions share a commonality in oxidative/nitrosative stress and mitochondrial dysfunction contributing to their pathogenesis. ß-Sitosterol, a plant sterol, has shown promise in mitigating oxidative/nitrosative stress, enhancing mitochondrial function, and exerting neuroprotective effects. In this study, we investigated the impact of ß-sitosterol on migraine-associated anxiety and whether this effect was associated with alleviation of oxidative/nitrosative stress and improvement in mitochondrial function. METHODS: Nitroglycerin was used to induce migraine in adult male Wistar rats. ß-Sitosterol treatment consisted of daily intraperitoneal injections (10 mg/kg) for 10 days following migraine induction. Anxiety levels were evaluated using open-field test (OFT) and hole-board test (HBT). Frontal cortex samples were analyzed for malondialdehyde (MDA), glutathione (GSH), reactive oxygen/nitrogen species, nitric oxide (NO) (markers of oxidative/nitrosative stress), and ATP (indicator of mitochondrial function). RESULTS: Migraine induction led to impaired performance in both the OFT and the HBT. Concurrently, it elevated MDA, reactive oxygen/nitrogen species, and NO levels while diminishing GSH levels in the frontal cortex, signifying heightened oxidative/nitrosative stress. Moreover, ATP levels decreased, indicating mitochondrial dysfunction. Treatment with ß-sitosterol significantly restored performance in both behavioral assays and normalized the levels of MDA, GSH, reactive oxygen/nitrogen species, NO, and ATP. CONCLUSION: ß-Sitosterol exerted anxiolytic effects in migraine, which can be attributed to its ability to ameliorate oxidative/nitrosative stress and enhance mitochondrial function.

Pituitary adenylate cyclase-activating polypeptide signalling as a therapeutic target in migraine.

Migraine is a disabling neurological disorder that affects more than one billion people worldwide. The clinical presentation is characterized by recurrent headache attacks, which are often accompanied by photophobia, phonophobia, nausea and vomiting. Although the pathogenesis of migraine remains incompletely understood, mounting evidence suggests that specific signalling molecules are involved in the initiation and modulation of migraine attacks. These signalling molecules include pituitary adenylate cyclase-activating polypeptide (PACAP), a vasoactive peptide that is known to induce migraine attacks when administered by intravenous infusion to people with migraine. Discoveries linking PACAP to migraine pathogenesis have led to the development of drugs that target PACAP signalling, and a phase II trial has provided evidence that a monoclonal antibody against PACAP is effective for migraine prevention. In this Review, we explore the molecular and cellular mechanisms of PACAP signalling, shedding light on its role in the trigeminovascular system and migraine pathogenesis. We then discuss emerging therapeutic strategies that target PACAP signalling for the treatment of migraine and consider the research needed to translate the current knowledge into a treatment for migraine in the clinic.

A Monoclonal Antibody to PACAP for Migraine Prevention.

BACKGROUND: Targeting pituitary adenylate cyclase-activating polypeptide (PACAP) is a new avenue for treating migraine. The efficacy and safety of intravenous Lu AG09222, a humanized monoclonal antibody directed against the PACAP ligand, for migraine prevention are unclear. METHODS: In a phase 2, double-blind, randomized, placebo-controlled trial, we enrolled adult participants (18 to 65 years of age) with migraine for whom two to four previous preventive treatments had failed to provide a benefit. The trial included a 4-week treatment period and an 8-week follow-up period. Participants were randomly assigned in a 2:1:2 ratio to receive a single-dose baseline infusion of 750 mg of Lu AG09222, 100 mg of Lu AG09222, or placebo. The primary end point was the mean change from baseline in the number of migraine days per month, during weeks 1 through 4, in the Lu AG09222 750-mg group as compared with the placebo group. RESULTS: Of 237 participants enrolled, 97 received 750 mg of Lu AG09222, 46 received 100 mg of Lu AG09222, and 94 received placebo. The mean number of baseline migraine days per month was 16.7 in the overall population, and the mean change from baseline over weeks 1 through 4 was -6.2 days in the Lu AG09222 750-mg group, as compared with -4.2 days in the placebo group (difference, -2.0 days; 95% confidence interval, -3.8 to -0.3; P = 0.02). Adverse events with a higher incidence in the Lu AG09222 750-mg group than in the placebo group during the 12-week observation period included coronavirus disease 2019 (7% vs. 3%), nasopharyngitis (7% vs. 4%), and fatigue (5% vs. 1%). CONCLUSIONS: In a phase 2 trial, a single intravenous infusion of 750 mg of Lu AG09222 showed superiority over placebo in reducing migraine frequency over the subsequent 4 weeks. (Funded by H. Lundbeck; HOPE ClinicalTrials.gov number, NCT05133323.).

Metabolomic profiling integrated with molecular exploring delineates the action of Ligusticum chuanxiong hort. on migraine.

INTRODUCTION: Ligusticum chuanxiong hort. (Chuanxiong, CX) is a well-known traditional edible-medicinal herb, especially in brain diseases. However, there is a lack of studies focusing on the action of CX in metabolites of migraine. HYPOTHESIS/PURPOSE: To investigate the action of the aqueous extract of CX (LCH) on nitroglycerin (NTG)-induced migraine. METHODS: The effects and mechanisms of LCH on migraine were evaluated in NTG-induced mice and rats. Laser speckle contrast imaging was performed to detect the cerebral blood flow. Metabolomic analysis in serum and mass spectrometry imaging in brain tissue from NTG-induced rats were conducted to explore the metabolites. The techniques including RT-qPCR, immunohistochemistry, and immunofluorescence were employed to estimate the molecular changes. RESULTS: Totally, 1480 metabolites were identified, among which, 50 and 49 differential metabolites were identified by t-test, fold change, and VIP score for NTG vs. CON and LCH+NTG vs. NTG, respectively. Next, 13 common real difference metabolites were revealed by comparative analysis, and KEGG annotation and enrichment analysis showed that the glutathione (GSH) metabolism pathway played important roles in migraine, whereas the glutamate could be metabolized to γ-glu-cys and converted to GSH. Molecular exploring further confirmed that LCH treatment increased the expression of essential components of GSH synthetase, such as GCLC and GCLM, and elevated the expression levels of Nrf-2 and its downstream targets including HO1 and NQO1. Moreover, the mass spectrometry imaging results found that LCH treatment promoted the synthesis of GSH and the spatial distribution of glucose as well as ATP metabolites to normal levels. CONCLUSION: To sum up, the present study firstly reveals that LCH plays a therapeutic role for migraine through glucose-glutamate-Nrf-2 axis, which might represent a promising approach in the development of advanced therapeutic strategies for migraine, and the LCH may be an effective drug or dietary supplement for relieving headache.

Study on the involvement of microglial S100A8 in neuroinflammation and microglia activation during migraine attacks.

BACKGROUND: Microglia is the primary source of inflammatory factors during migraine attacks. This study aims to investigate the role of microglia related genes (MRGs) in migraine attacks. METHODS: The RNA sequencing results of migraineurs and the panglaodb database were used to obtain differentially expressed genes (DEGs) in migraine related to microglia. A migraine rat model was established for validating and localizing of the MRGs, and subsequent screening for target genes was conducted. A shRNA was designed to interference the expression of target genes and administered into the trigeminal ganglion (TG) of rats. Pain sensitivity in rats was evaluated via the hot water tail-flick (HWTF) and formalin-induced pain (FIP) experiments. ELISA was used to quantify the levels of inflammatory cytokines and CGRP. WB and immunofluorescence assays were applied to detect the activation of microglia. RESULTS: A total of five DEGs in migraine related to microglia were obtained from RNA sequencing and panglaodb database. Animal experiments showed that these genes expression were heightened in the TG and medulla oblongata (MO) of migraine rats. The gene S100A8 co-localized with microglia in both TG and MO. The HWTF and FIP experiments demonstrated that interference with S100A8 alleviated the sense of pain in migraine rats. Moreover, the levels of TNFα, IL-1ß, IL-6, and CGRP in the TG and MO of rats in the model rats were increased, and the expression of microglia markers IBA-1, M1 polarization markers CD86 and iNOS was upregulated. Significantly, interference with S100A8 reversed these indicators. CONCLUSION: Interference with S100A8 in microglia increased the pain threshold during migraine attacks, and inhibited neuroinflammation and microglia activation.

KCNG4 Genetic Variant Linked to Migraine Prevents Expression of KCNB1.

Migraines are a common type of headache affecting around 15% of the population. The signalling pathways leading to migraines have not been fully understood, but neuronal voltage-gated ion channels, such as KCNG4, have been linked to this pathology. KCNG4 (Kv6.4) is a silent member of the superfamily of voltage-gated potassium (Kv) channels, which expresses in heterotetramers with members of the KCNB (Kv2) family. The genetic variant Kv6.4-L360P has previously been linked to migraines, but their mode of action remains unknown. Here, we characterized the molecular characteristics of Kv6.4-L360P when co-expressed with Kv2.1. We found that Kv6.4-L360P almost completely abolishes Kv2 currents, and we propose that this mechanism in the trigeminal system, linked to the initiation of migraine, leads to the pathology.

Metabolomics integrated with mass spectrometry imaging reveals novel action of tetramethylpyrazine in migraine.

Migraine as a common neurological disorder still lacks effective therapies. Tetramethylpyrazine (TMP) is the main bioactive component from Ligusticum chuanxiong hort., a traditional edible-medicinal herb. This study aimed to investigate the action of TMP on migraine by metabolomics with mass spectrometry imaging (MSI) analysis and molecular exploring, including random forest model analysis, KEGG enrichment analysis and metabolite-metabolite interaction network analysis. The results indicated that 26 key representative metabolic biomarkers were identified, especially γ-glu-cys, which were highly related to glutathione (GSH) metabolism. MSI found the abundance of eleven endogenous metabolites were modulated by TMP, particularly glucose, the most important energy metabolism molecule, and GSH were increased that maintains intracellular redox balance, which was consistent with activation of Nrf2 signals by TMP. These findings provide insights into the effectiveness of metabolomics integrated with MSI in explaining the metabolic mechanisms of TMP, and afford valuable information for healthy development of TMP in migraine.