Differential expression of components of the CGRP-receptor family in human coronary and human middle meningeal arteries: functional implications.

BACKGROUND: Different responses in human coronary arteries (HCA) and human middle meningeal arteries (HMMA) were observed for some of the novel CGRP receptor antagonists, the gepants, for inhibiting CGRP-induced relaxation. These differences could be explained by the presence of different receptor populations in the two vascular beds. Here, we aim to elucidate which receptors are involved in the relaxation to calcitonin gene-related peptide (CGRP), adrenomedullin (AM) and adrenomedullin 2 (AM2) in HCA and HMMA. METHODS: RNA was isolated from homogenized human arteries (23 HCAs; 12 F, 11 M, age 50 ± 3 years and 26 HMMAs; 14 F, 12 M, age 51 ± 3 years) and qPCR was performed for different receptor subunits. Additionally, relaxation responses to CGRP, AM or AM2 of the human arteries were quantified using a Mulvany myograph system, in the presence or absence of the adrenomedullin 1 receptor antagonist AM22-52 and/or olcegepant. RESULTS: Calcitonin-like receptor (CLR) mRNA was expressed equally in both vascular beds, while calcitonin receptor (CTR) and receptor activity-modifying protein 3 (RAMP3) expression was low and could not be detected in all samples. RAMP1 expression was similar in HCA and HMMA, while RAMP2 expression was higher in HMMA. Moreover, receptor component protein (RCP) expression was higher in HMMA than in HCA. Functional experiments showed that olcegepant inhibits relaxation to all three agonists in both vascular beds. In HCA, antagonist AM22-52 did not inhibit relaxation to any of the agonists, while a trend for blocking relaxation to AM and AM2 could be observed in HMMA. CONCLUSION: Based on the combined results from receptor subunit mRNA expression and the functional responses in both vascular tissues, relaxation of HCA is mainly mediated via the canonical CGRP receptor (CLR-RAMP1), while relaxation of HMMA can be mediated via both the canonical CGRP receptor and the adrenomedullin 1 receptor (CLR-RAMP2). Future research should investigate whether RAMP2 predominance over RAMP1 in the meningeal vasculature results in altered migraine susceptibility or in a different response to anti-migraine medication in these patients. Moreover, the exact role of RCP in CGRP receptor signalling should be elucidated in future research.

Effect of fasting-induced headache on calcitonin gene related peptide (CGRP) and other clinical biomarkers on the first day of Ramadan: Sub-analysis from a randomized open label clinical trial.

BACKGROUND: Fasting-induced headaches (FIHs) have been shown to occur on the first day of Ramadan and clearly decline thereafter. Despite the wealth of knowledge about different types of headaches (e.g., migraine-, cluster-, and tension-type headaches), research on the mechanism underlying FIHs, as well as their treatment, remains scarce. Our study aimed to investigate any association between FIHs during the first day of Ramadan and potential headache-related biomarkers, including fasting blood glucose (FBG), C-reactive protein (CRP), magnesium, vitamin B9, vitamin B12, homocysteine, and calcitonin gene related peptide (CGRP), and to assess whether a prophylactic use of paracetamol may influence these biomarkers. METHODS: As part of a randomized, open-label clinical trial that evaluated the effect of paracetamol as a prophylactic therapy for FIH, blood samples from stratified subjects in the prophylaxis and control groups were withdrawn while fasting after the 1st dose of paracetamol (in the prophylaxis group) and prior to reporting headache occurrence. RESULTS: Plasma and serum were separated for 61 subjects; 31 and 30 subjects from the prophylaxis and control groups, respectively. Overall, no significant differences were found in the levels of FBG, CRP, magnesium, vitamin B9, and vitamin B12 in headache-suffering subjects compared to those without headache despite the use of paracetamol for prophylaxis. Homocysteine, however, was significantly reduced in all subjects who experienced FIH compared to those without headache (median 6.9 [1.6] vs. 7.7 [2.7] umol/L; p = 0.041). On the contrary, when the CGRP was measured using immunoassay, it was found to be significantly elevated in all headache-suffering subjects compared to those without headache (median 126.1 [17.7] vs. 105.8 [19.6] pg/mL; p ≤ 0.0001). This difference was maintained upon comparing the headache to non-headache subjects in both the prophylaxis (median 121.5 [15.4] vs. 105.8 [9.4] pg/mL; p < 0.01) and control groups (median 128.5 [28.3] vs. 105.8 [23.8] pg/mL; p < 0.01). Additionally, an elevated CGRP level was found to increase the odds of having a FIH [OR = 1.32; 95%CI 1.06-1.22]. CONCLUSIONS: Our findings revealed the role of CGRP in FIHs for the first time and suggest further investigation in signaling pathways downstream CGRP receptors. Furthermore, the modulation CGRP or CGRP receptors could have a clinical application in the prevention of FIHs. TRIAL REGISTRATION: This study was registered with the Saudi Food and Drug Authority in the Saudi Clinical Trials Registry (SCTR; No. 22122102).

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.

Preventive drug treatments for adults with chronic migraine: a systematic review with economic modelling.

Background: Chronic migraine is a disabling condition, affecting 2-4% of adults globally. With the introduction of expensive calcitonin gene-related peptide monoclonal antibodies, it is timely to compare the clinical effectiveness and cost-effectiveness of preventive drugs for chronic migraine. Objective: To assess the clinical effectiveness and cost-effectiveness of medications used for chronic migraine through systematic reviews and economic modelling. Eligibility criteria: Randomised controlled trials of drug treatments for efficacy with > 100 participants with chronic migraine per arm; for adverse events > 100 participants with episodic or chronic migraine per arm. Previous economic analyses of preventive drugs for chronic migraine. Data sources: Eight databases. Reviews methods: Systematic reviews, network meta-analysis and economic modelling. Outcomes: Monthly headache days, monthly migraine days, headache-related quality of life, cost-effectiveness. Results: We found 51 individual articles, reporting 11 randomised controlled trials, testing 6 drugs (topiramate, Botox, eptinezumab, erenumab, fremanezumab, galcanezumab), versus placebo, on 7352 adults with chronic migraine. Calcitonin gene-related peptide monoclonal antibodies, Botox and topiramate reduced headache/migraine days by 2.0-2.5, just under two, or by less than 1.5 days per month, respectively. In the network meta-analysis, eptinezumab 300 mg and fremanezumab monthly ranked in first place in both monthly headache day and monthly migraine day analyses. The calcitonin gene-related peptide monoclonal antibodies were consistently the best choices for headache/migraine days and headache-related quality of life. Topiramate was very unlikely to be the best choice for headache/migraine days and headache-related quality of life when compared to calcitonin gene-related peptide monoclonal antibodies or Botox. We found no trials of the commonly used drugs, such as propranolol or amitriptyline, to include in the analysis. The adverse events review included 40 randomised controlled trials with 25,891 participants; 3 additional drugs, amitriptyline, atogepant and rimegepant, were included. There were very few serious adverse events - none of which were linked to the use of these medications. Adverse events were common. Most people using some calcitonin gene-related peptide monoclonal antibodies reported injection site issues; and people using topiramate or amitriptyline had nervous system or gastrointestinal issues. The cost-effectiveness review identified 16 studies evaluating chronic migraine medications in adults. The newer, injected drugs are more costly than the oral preventatives, but they were cost-effective. Our economic model showed that topiramate was the least costly option and had the fewest quality-adjusted life-year gains, whereas eptinezumab 300 mg was more costly but generated the most quality-adjusted life-year gains. The cost-effectiveness acceptability frontier showed that topiramate was the most cost-effective medication if the decision maker is willing to pay up to £50,000 per quality-adjusted life-year. Our consensus workshop brought together people with chronic migraine and headache experts. Consensus was reached on the top three recommendations for future research on medications to prevent chronic migraine: (1) calcitonin gene-related peptide monoclonal antibodies and Botox versus calcitonin gene-related peptide monoclonal antibodies, (2) candesartan versus placebo and (3) flunarizine versus placebo. Limitations: Topiramate was the only oral drug for which we were able to include data. We did not find sufficient quality evidence to support the use of other oral drugs. Conclusions: We did not find evidence that the calcitonin gene-related peptide monoclonal antibodies are more clinically and cost-effective when compared to topiramate or Botox. We identified directions for future research these drugs might take. Study registration: This study is registered as PROSPERO CRD42021265990, CRD42021265993 and CRD42021265995. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR132803) and is published in full in Health Technology Assessment; Vol. 28, No. 63. See the NIHR Funding and Awards website for further award information.

Chronic migraine is a disabling condition that can destroy work and family life. Treatments include cheap tablets (e.g. amitriptyline, propranolol and topiramate), Botox and expensive new drugs (the calcitonin gene-related peptide monoclonal antibodies). It is not known which of these drugs is the best choice. We wanted to find out which of these drugs works best. We wanted to know if they reduced the number of headache/migraine days and improved headache-related quality of life, how many side effects people experienced, and if they provided good value for the National Health Service. We first looked for research comparing these drugs to placebo (fake) drugs, and to each other. We then worked out which provide best value for money. Calcitonin gene-related peptide monoclonal antibodies reduced headache/migraine days by 2.0­2.5 days per month; Botox reduced headache/migraine days per month by around 1.9; and topiramate reduced headache/migraine days by 1.1­1.5 days per month. Many people taking topiramate or amitriptyline have nervous system and/or stomach/bowel side effects. Some people using calcitonin gene-related peptide monoclonal antibodies reported side effects associated with injections. Some calcitonin gene-related peptide monoclonal antibodies and Botox provide worthwhile benefits on headache-related quality of life. We were not able to identify any studies of sufficient quality to assess the effectiveness of other oral drugs. The best value drug was topiramate which gave better health outcomes at a lower cost than the placebos. After sharing the results with a panel of people with chronic migraine and headache experts, we identified a need for new studies comparing commonly used cheap oral drugs with placebo, Botox and calcitonin gene-related peptide monoclonal antibodies.

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 .

Interplay between cannabinoids and the neuroimmune system in migraine.

Migraine is a common and complex neurological disorder that has a high impact on quality of life. Recent advances with drugs that target the neuropeptide calcitonin gene-related peptide (CGRP) have helped, but treatment options remain insufficient. CGRP is released from trigeminal sensory fibers and contributes to peripheral sensitization, perhaps in part due to actions on immune cells in the trigeminovascular system. In this review, we will discuss the potential of cannabinoid targeting of immune cells as an innovative therapeutic target for migraine treatment. We will cover endogenous endocannabinoids, plant-derived phytocannabinoids and synthetically derived cannabinoids. The focus will be on six types of immune cells known to express multiple cannabinoid receptors: macrophages, monocytes, mast cells, dendritic cells, B cells, and T cells. These cells also contain receptors for CGRP and as such, cannabinoids might potentially modulate the efficacy of current CGRP-targeting drugs. Unfortunately, to date most studies on cannabinoids and immune cells have relied on cell cultures and only a single preclinical study has tested cannabinoid actions on immune cells in a migraine model. Encouragingly, in that study a synthetically created stable chiral analog of an endocannabinoid reduced meningeal mast cell degranulation. Likewise, clinical trials evaluating the safety and efficacy of cannabinoid-based therapies for migraine patients have been limited but are encouraging. Thus, the field is at its infancy and there are significant gaps in our understanding of the impact of cannabinoids on immune cells in migraine. Future research exploring the interactions between cannabinoids and immune cells could lead to more targeted and effective migraine treatments.

Onabotulinumtoxin A for the Treatment of Post-Traumatic Headache: Is It Better than Anti-CGRP Antibodies?

Post-traumatic headache (PTH) is a common and debilitating consequence of traumatic brain injury (TBI), often resembling migraine and tension-type headaches. Despite its prevalence, the optimal treatment for PTH remains unclear, with current strategies largely extrapolated from other headache disorders. This review evaluates the use of onabotulinumtoxin A (ONA) and anti-calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) in the treatment of PTH. A comprehensive literature search was conducted on PubMed, including studies published up to September 2024, focusing on the efficacy, safety, and mechanisms of onabotulinumtoxin A and anti-CGRP mAbs in PTH. Both clinical trials and observational studies were reviewed. ONA, widely recognized for its efficacy in chronic migraine, has shown limited benefits in PTH with only one trial involving abobotulinumtoxin A in a cohort of 40 subjects. A phase 2 trial with fremanezumab, an anti-CGRP monoclonal antibody, failed to demonstrate significant efficacy in PTH, raising questions about the utility of targeting CGRP in this condition. ONA may offer advantages over anti-CGRP mAbs, not only in terms of its broader mechanism of action but also in cost-effectiveness and higher patient adherence. Both ONA and anti-CGRP mAbs are potential options for the management of PTH, but the current evidence is insufficient to establish clear guidelines. The negative results from the fremanezumab trial suggest that CGRP inhibition may not be sufficient for treating PTH, whereas onabotulinumtoxin A's ability to target multiple pain pathways may make it a more promising candidate.

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.

ILC2-derived CGRP triggers acute inflammation and nociceptive responses in bacterial cystitis.

Calcitonin gene-related peptide (CGRP), a neuropeptide involved in nociceptor neuronal function, plays a critical role in mediating neuroinflammation and pain. In this study, we find that bladder group 2 innate lymphoid cells (ILC2s) function as primary producers of CGRP in the early phase of bacterial cystitis, contributing to increased inflammation, altered voiding behavior, and heightened pelvic allodynia. Furthermore, we demonstrate that interleukin (IL)-33, a cytokine secreted by urothelial cells, upregulates CGRP production by ILC2s in the bladder during uropathogenic Escherichia coli (UPEC) infection. Moreover, our research reveals that monocytes expressing high levels of receptor activity-modifying protein 1 (RAMP1), a CGRP receptor, mediate the pro-inflammatory effects of CGRP-producing ILC2s. In summary, our results underscore the significance of the immune cell-derived neuropeptides in the pathology of UPEC infection, suggesting a promising therapeutic approach targeting the IL-33-ILC2-CGRP axis for managing lower urinary tract symptoms in bacterial cystitis.

Procalcitonin levels in severe fever with thrombocytopenia syndrome patients: a retrospective investigation in Anhui, China.

INTRODUCTION: This work aim to evaluate the association of procalcitonin (PCT) levels with disease severity and prognosis in severe fever with thrombocytopenia syndrome (SFTS) patients. METHODOLOGY: The medical records of 158 confirmed SFTS patients at two hospitals were reviewed. The patients were divided into survival group and nonsurvival group according to outcomes. Additionally, to assess mortality rates at different PCT levels, patients were divided into two groups, PCT < 0.25 ng/mL and PCT ≥ 0.25 ng/mL. RESULTS: Among the 158 confirmed SFTS patients, 26 died; the case fatality rate was 16.46%. PCT data were available for 132 of these patients; 66 were in the PCT < 0.25 ng/mL group, and 66 were in the PCT ≥ 0.25 ng/mL group. The SFTS patients had abnormal results on routine blood tests, indicating varying degrees of thrombocytopenia and leukopenia, and most patients presented with multiple organ dysfunction. The PCT level of the nonsurvival group was significantly higher than that of the survival group (p < 0.01). Additionally, the mortality of the PCT ≥ 0.25 ng/mL group was significantly higher than that of the PCT < 0.25 ng/mL group (p < 0.01); mortality increased sharply ( ≥ 25%) when the PCT level exceeded 0.1 ng/mL. CONCLUSIONS: PCT levels in SFTS patients are closely related to the severity and prognosis of their illness. The serum PCT level is a promising predictor of mortality and severity in SFTS patients when considered in combination with clinical data and other laboratory tests.

Case series on monoclonal antibodies targeting calcitonin gene-related peptide in migraine patients during pregnancy: Enhancing safety data.

BACKGROUND: Monoclonal antibodies targeting calcitonin gene-related peptide (CGRP-mAbs) are approved for adult migraine prevention but pose safety concerns in pregnancy. We assess the safety of CGRP-mAbs in the periconceptional period through a case series and literature review. METHODS: Six migraine-diagnosed women received CGRP-mAbs; treatment ceased upon pregnancy. We collected data and conducted safety assessments. To provide a comprehensive context, we performed a literature review. RESULTS: The series includes three erenumab, two fremanezumab and one galcanezumab case. A fremanezumab recipient experienced miscarriage; severe perinatal asphyxia linked to dystocia occurred with erenumab (140 mg). Database reviews revealed 63 spontaneous abortions, eight premature births, and seven birth defects among 286 World Health Organization and 65 European Medicines Agency cases. These rates align with untreated population rates. CONCLUSIONS: CGRP-mAbs use in the periconceptional period does not lead to clinically significant increase in pregnancy-related pathology or adverse effects on newborns within our case series and the literature reviewed.

Filling the data gap on CGRP mAb therapy in low- to middle-income countries in Southeast Asia: insights from a real-world study in Thailand.

BACKGROUND: Most real-world data on CGRP mAbs have been published from high-income countries such as the USA, Western countries, Japan, Korea, and Singapore. However, data from low- and middle-income countries in Southeast Asia is lacking. This is the first real-world study from Thailand to describe the efficacy of CGRP mAbs therapy in migraine patients and to analyze the response trends between episodic migraine and chronic migraine. METHODS: We conducted a single-center, real-world retrospective chart review study with an observation period of 6 months after CGRP mAbs initiation. We aim to compare treatment responses to CGRP mAbs between EM and CM patients. RESULTS: A total of 47 Thai patients were enrolled (median [IQR] age 37.2 [28.6-50.4] years; 85.1%F, 44.7% EM; 70.2% galcanezumab). There was no difference in baseline characteristics and migraine disability assessment (MIDAS) between EM and CM. The overall ≥ 30%, ≥ 50%, and ≥ 70% monthly migraine day reduction rates at 6 months were 89.0%, 71.6%, and 58.5% with higher responders in EM. There was a significant decrease in monthly headache days (MHDs) over time (adjusted ß = -0.42, p < 0.001) and a significant decrease in MIDAS score over time after the initiation of CGRP mAbs (adjusted ß = -1.12, p = 0.003). However, there were no differences between the two diagnoses. There was no significant decrease in the number of abortive medication pills used over time after the initiation of CGRP mAbs. CM had a significantly steeper trend compared to those with EM. CONCLUSION: The first real-world study in Thailand demonstrated that CGRP mAbs therapy had efficacy for migraine treatment, as evidenced by a reduction in MHDs, decreased disability, and reduced use of abortive medications. Additionally, the response pattern to CGRP mAbs therapy was similar between EM and CM in terms of MHDs reduction and MIDAS score improvement.

Efficacy of galcanezumab in migraine central sensitization

Galcanezumab, a monoclonal antibody targeting the calcitonin gene-related peptide pathway (CGRP mAb), acts peripherally due to its large size. However, recent studies have suggested that CGRP mAbs may also have a central mode of action. This study aimed to evaluate the central effects of galcanezumab on migraine central sensitization.This prospective real-world study was conducted at three headache centers in Japan between May 2021 and May 2022. Patients treated with galcanezumab for migraines were included in the study. The primary outcome was the change in the validated Central Sensitization Inventory (CSI) score from baseline to six months of treatment. We also assessed changes in the Allodynia Symptom Checklist (ASC-12) score. Eighty-six patients with migraine (73 female and 13 male) were analyzed. At 6 months, CSI and ASC-12 scores were significantly reduced compared to baseline (CSI: 36.0 vs. 29.3, p < 0.001; and ASC-12: 5.55 vs. 4.26, p < 0.01). Furthermore, these effects were observed as early as three months of treatment. In this study, we demonstrated the real-world efficacy of galcanezumab in improving central sensitization in migraine, with significant effects seen in the early phase of treatment. Trial registration: This study was registered with UMIN-CTR on May 2, 2021 (UMIN000044096).

Genetic variants associated with response to anti-CGRP monoclonal antibody therapy in a chronic migraine Han Chinese population.

BACKGROUND: Anti-calcitonin gene-related peptide (CGRP) monoclonal antibodies have emerged as promising therapeutic options for the treatment of chronic migraine. However, treatment response varies considerably among individuals, suggesting a potential role for genetic factors. This study aimed to identify genetic variants affecting the efficacy of anti-CGRP monoclonal antibody therapy in chronic migraine among the Han Chinese population in Taiwan to enhance treatment precision and to understand the genetic architecture of migraine. METHODS: We conducted a quantitative trait locus (QTL) association study in patients with chronic migraines from a tertiary medical center in Taiwan using the Taiwan Precision Medicine Array Chip. The patients received fremanezumab or galcanezumab for at least 12 weeks. Treatment efficacy was assessed based on the improvement rate in monthly migraine days. Genetic variants were identified, and their associations with treatment efficacy were examined through quantitative trait loci analysis, linkage disequilibrium studies, and functional annotations using the Gene Ontology database. RESULTS: Six single nucleotide polymorphisms (SNPs) relative variants were significantly associated with anti-CGRP therapy response (p < 1 × 10- 7): rs116870564, rs75244870, rs56216870, rs12938101, rs74655790, and rs149540851. These variants are located in or near genes, including LRRC4C, ATAD2B, and OXR1, which are involved in neuronal development, DNA-dependent ATPase activity, and oxidation-reduction processes, respectively. The rs116870564 variant in LRRC4C showed the strongest association (ß = -0.551, p = 6.65 × 10- 9). The functional impact of these variants is attributed to their regulatory effects on gene expression, which are influenced by intron splicing regulation, transcription factors, and changes in chromatin structure. CONCLUSION: The identification of key genetic markers associated with response to anti-CGRP therapy emphasizes the importance of genetic variability in treatment efficacy. This could lead to more personalized chronic migraine management strategies and tailored therapeutic approaches based on individual genetic profiles. Further research in larger, diverse populations is warranted to validate these findings and refine our understanding of the role of CGRP in chronic migraine pathophysiology. TRIAL REGISTRATION: Not applicable.

Lung-innervating nociceptor sensory neurons promote pneumonic sepsis during carbapenem-resistant Klebsiella pneumoniae lung infection.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) causes Gram-negative lung infections and fatal pneumonic sepsis for which limited therapeutic options are available. The lungs are densely innervated by nociceptor sensory neurons that mediate breathing, cough, and bronchoconstriction. The role of nociceptors in defense against Gram-negative lung pathogens is unknown. Here, we found that lung-innervating nociceptors promote CRKP pneumonia and pneumonic sepsis. Ablation of nociceptors in mice increased lung CRKP clearance, suppressed trans-alveolar dissemination of CRKP, and protected mice from hypothermia and death. Furthermore, ablation of nociceptors enhanced the recruitment of neutrophils and Ly6Chi monocytes and cytokine induction. Depletion of Ly6Chi monocytes, but not of neutrophils, abrogated lung and extrapulmonary CRKP clearance in ablated mice, suggesting that Ly6Chi monocytes are a critical cellular population to regulate pneumonic sepsis. Further, neuropeptide calcitonin gene-related peptide suppressed the induction of reactive oxygen species in Ly6Chi monocytes and their CRKP-killing abilities. Targeting nociceptor signaling could be a therapeutic approach for treating multidrug-resistant Gram-negative infection and pneumonic sepsis.

PAC1 constrains type 2 inflammation through promotion of CGRP signaling in ILC2s.

Dysfunction of group 2 innate lymphoid cells (ILC2s) plays an important role in the development of type 2 inflammation-related diseases such as asthma and pulmonary fibrosis. Notably, neural signals are increasingly recognized as pivotal regulators of ILC2s. However, how ILC2s intrinsically modulate their responsiveness to these neural signals is still largely unknown. Here, using single-cell RNA-Seq, we found that the immune-regulatory molecule phosphatase of activated cells 1 (PAC1) selectively promoted the signaling of the neuropeptide calcitonin gene-related peptide (CGRP) in ILC2s in a cell-intrinsic manner. Genetic ablation of PAC1 in ILC2s substantially impaired the inhibitory effect of CGRP on proliferation and IL-13 secretion. PAC1 deficiency significantly exacerbated allergic airway inflammation induced by Alternaria alternata or papain in mice. Moreover, in human circulating ILC2s, the expression level of PAC1 was also significantly negatively correlated with the number of ILC2s and their expression level of IL13. Mechanistically, PAC1 was necessary for ensuring the expression of CGRP response genes by influencing chromatin accessibility. In summary, our study demonstrated that PAC1 is an important regulator of ILC2 responses, and we propose that PAC1 is a potential target for therapeutic interventions in type 2 inflammation-related diseases.

Crosstalk between bone metastatic cancer cells and sensory nerves in bone metastatic progression.

Although the role of peripheral nerves in cancer progression has been appreciated, little is known regarding cancer/sensory nerve crosstalk and its contribution to bone metastasis and associated pain. In this study, we revealed that the cancer/sensory nerve crosstalk plays a crucial role in bone metastatic progression. We found that (i) periosteal sensory nerves expressing calcitonin gene-related peptide (CGRP) are enriched in mice with bone metastasis; (ii) cancer patients with bone metastasis have elevated CGRP serum levels; (iii) bone metastatic patient tumor samples express elevated calcitonin receptor-like receptor (CRLR, a CGRP receptor component); (iv) higher CRLR levels in cancer patients are negatively correlated with recurrence-free survival; (v) CGRP induces cancer cell proliferation through the CRLR/p38/HSP27 pathway; and (vi) blocking sensory neuron-derived CGRP reduces cancer cell proliferation in vitro and bone metastatic progression in vivo. This suggests that CGRP-expressing sensory nerves are involved in bone metastatic progression and that the CGRP/CRLR axis may serve as a potential therapeutic target for bone metastasis.

The effect of CGRP and SP and the cell signaling dialogue between sensory neurons and endothelial cells.

Increasing evidences demonstrate the role of sensory innervation in bone metabolism, remodeling and repair, however neurovascular coupling in bone is rarely studied. Using microfluidic devices as an indirect co-culture model to mimic in vitro the physiological scenario of innervation, our group demonstrated that sensory neurons (SNs) were able to regulate the extracellular matrix remodeling by endothelial cells (ECs), in particular through sensory neuropeptides, i.e. calcitonin gene-related peptide (CGRP) and substance P (SP). Nonetheless, still little is known about the cell signaling pathways and mechanism of action in neurovascular coupling. Here, in order to characterize the communication between SNs and ECs at molecular level, we evaluated the effect of SNs and the neuropeptides CGRP and SP on ECs. We focused on different pathways known to play a role on endothelial functions: calcium signaling, p38 and Erk1/2; the control of signal propagation through Cx43; and endothelial functions through the production of nitric oxide (NO). The effect of SNs was evaluated on ECs Ca2+ influx, the expression of Cx43, endothelial nitric oxide synthase (eNOS) and nitric oxide (NO) production, p38, ERK1/2 as well as their phosphorylated forms. In addition, the role of CGRP and SP were either analyzed using respective antagonists in the co-culture model, or by adding directly on the ECs monocultures. We show that capsaicin-stimulated SNs induce increased Ca2+ influx in ECs. SNs stimulate the increase of NO production in ECs, probably involving a decrease in the inhibitory eNOS T495 phosphorylation site. The neuropeptide CGRP, produced by SNs, seems to be one of the mediators of this effect in ECs since NO production is decreased in the presence of CGRP antagonist in the co-culture of ECs and SNs, and increased when ECs are stimulated with synthetic CGRP. Taken together, our results suggest that SNs play an important role in the control of the endothelial cell functions through CGRP production and NO signaling pathway.

Assessment of Bone Mineral Density Over 1 Year in a Cross-Sectional Cohort of Migraine Patients Receiving Anti-CGRP Monoclonal Antibodies.

BACKGROUND: Calcitonin gene-related peptide (CGRP), implicated in migraine pain, also possesses bone anabolic properties, which leads to the possibility that monoclonal antibodies targeting CGRP (anti-CGRPs) might increase the risk of bone density abnormalities. OBJECTIVE: The objective of this study was to explore bone mineral density abnormalities in a cohort of migraine patients treated with anti-CGRPs. METHODS: This was a single-center, cross-sectional, cohort study including migraine patients who underwent a densitometry assessment during anti-CGRP treatment. We assessed the frequency of osteopenia or osteoporosis (OSTEO+ status), defined as a bone mineral density T-score of -1 to -2.5, and <-2.5 standard deviations from the young female adult mean, respectively. Additionally, the association of OSTEO+ status with anti-CGRP treatment duration and primary osteoporosis' risk factors was investigated using logistic regression models. RESULTS: Data from 51 patients (43 female, mean age 46 ± 13.9 years) were evaluated. The mean duration of anti-CGRP treatment was 15.7 (±11.8) months. Twenty-seven patients (53%) were OSTEO+ (n = 22 osteopenia; n = 5 osteoporosis). In the final model, menopause [odds ratio 11.641 (95% confidence interval 1.486-91.197), p = 0.019] and anti-seizure drug use [odds ratio 12.825 (95% confidence interval 1.162-141.569), p = 0.037] were associated with OSTEO+ status. CONCLUSIONS: In our cohort of migraine patients, no evidence of an association between anti-CGRP treatment duration and an increasing risk of bone mineral density abnormalities was found. However, these findings are preliminary and necessitate further longitudinal research with larger cohorts and extended follow-up to be validated.

CGRP inhibits SARS-CoV-2 infection of bronchial epithelial cells, and its pulmonary levels correlate with viral clearance in critical COVID-19 patients.

Upon infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), patients with critical coronavirus disease 2019 (COVID-19) present with life-threatening respiratory distress, pulmonary damage, and cytokine storm. One unexplored component in COVID-19 is the neuropeptide calcitonin gene-related peptide (CGRP), which is highly abundant in the airways and could converge in multiple aspects of COVID-19-related pulmonary pathophysiology. Whether CGRP affects SARS-CoV-2 infection directly remains elusive. We show that in critical COVID-19 patients, CGRP is increased in both plasma and lungs. Importantly, CGRP pulmonary levels are elevated in early SARS-CoV-2-positive patients and restored to baseline upon subsequent viral clearance in SARS-CoV-2-negative patients. We further show that CGRP and its stable analog SAX directly inhibit infection of bronchial Calu-3 epithelial cells with SARS-CoV-2 Omicron and Alpha variants in a dose-dependent manner. Both pre- and post-infection treatments with CGRP and/or SAX are enough to block SARS-CoV-2 productive infection of Calu-3 cells. CGRP-mediated inhibition occurs via activation of the CGRP receptor and involves down-regulation of both SARS-CoV-2 entry receptors at the surface of Calu-3 cells. Together, we propose that increased pulmonary CGRP mediates beneficial viral clearance in critical COVID-19 patients by directly inhibiting SARS-CoV-2 propagation. Hence, CGRP-based interventions could be harnessed for management of COVID-19.IMPORTANCEThe neuropeptide CGRP is highly abundant in the airways. Due to its immunomodulatory, vasodilatory, and anti-viral functions, CGRP could affect multiple aspects of COVID-19-related pulmonary pathophysiology. Yet, the interplay between CGRP and SARS-CoV-2 during COVID-19 remains elusive. Herein, we show that pulmonary levels of CGRP are increased in critical COVID-19 patients, at an early stage of their disease when patients are SARS-CoV-2-positive. Upon subsequent viral clearance, CGRP levels are restored to baseline in SARS-CoV-2-negative patients. We further show that pre- and post-infection treatments with CGRP directly inhibit infection of Calu-3 bronchial epithelial cells with SARS -CoV-2, via activation of the CGRP receptor leading to decreased expression of both SARS-CoV-2 entry receptors. Together, we propose that increased pulmonary CGRP is beneficial in COVID-19, as CGRP-mediated inhibition of SARS-CoV-2 infection could contribute to viral clearance in critical COVID-19 patients. Accordingly, CGRP-based formulations could be useful for COVID-19 management.