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Background Acute therapies targeting calcitonin gene-related peptide (CGRP) for episodic migraine (EM) demonstrate efficacy in women, but evidence of efficacy in men remains to be established. By contrast, CGRP targeting therapies for migraine prevention are effective in both men and women with frequent EM or chronic migraine (CM). Preclinical studies have shown that supradural application of CGRP preferentially produces migraine-like pain behaviors in female rodents. We hypothesized that, in male mice, increased frequency of migraine-like pain may sensitize to nociceptive effects of CGRP and this might be associated with altered expression of CGRP in trigeminal ganglion (TG) neurons and/or in their dural projections. Methods CM was modeled in male and female mice by repeated administration of nitroglycerin (NTG). Medication overuse headache (MOH), a form of CM, was modeled by repeated daily administration of sumatriptan. Following resolution of transient cutaneous allodynia (CA) elicited by NTG or sumatriptan, mice received a sex specific subthreshold dose of supradural CGRP that does not elicit CA in naïve male or female mice, and CA was evaluated. CGRP-positive cell bodies in the ophthalmic V1 region of the trigeminal ganglion (TGV1) and CGRP-positive nerve fibers innervating the dura mater were assessed. Results Supradural administration of 1 pg of CGRP produced migraine-like pain behaviors in female, but not male, mice; a ten-fold lower dose was established as subthreshold in naïve female mice. Repeated NTG or sumatriptan produced transient CA in both female and male mice that resolved within 8–11 days after treatment cessation. Following resolution of CA, previously subthreshold doses of CGRP elicited CA in CM and MOH models in mice of both sexes, with no effects observed in vehicle treated controls. A higher number of CGRP-positive neurons in the TGV1 was found in naïve female compared to male mice. The number of CGRP-positive TGV1 neurons was increased in both sexes following repeated NTG. Similar nerve fiber density was observed in the dura mater of male and female mice and no differences were detected following repeated NTG. Conclusions As previously reported, CGRP produced female-selective migraine-like pain behaviors in naïve mice. Consistent with behavioral effects, female mice demonstrated a higher number of CGRP-positive cells in the TGV1. These findings appear relevant to clinical observations of female efficacy of CGRP-receptor antagonists for acute treatment in EM patients. In models of CM or MOH that are characterized by increased frequency of migraine-like pain, previously subthreshold doses of supradural CGRP now elicited migraine-like nociceptive behaviors in mice of both sexes. The increased pain responses were accompanied by increased number CGRP positive TGV1 cells in the NTG model in both female and male mice. These data suggest that increased frequency of migraine promotes physiological changes including increased expression of TGV1 CGRP along with sensitization to CGRP-induced nociception in both males and females. Thus, as EM transforms to CM, CGRP-dependent mechanisms may become increasingly important, consistent with observations of efficacy of CGRP targeting therapies for migraine prevention in both men and women. Our results also suggest the possibility of enhanced efficacy of CGRP-receptor antagonists for the acute treatment of migraine in men as migraine frequency increases.

Introduction: Coagulation factor XI (FXI) inhibitors have shown a better safety profile than other anticoagulants, offering similar reductions in ischemic stroke (IS) risk with a lower risk of intracerebral hemorrhage (ICH). The APOE ε4 genotype is associated with increased risks of both IS and ICH, likely due to its effects on lipid levels, intracranial atherosclerosis, and cerebral amyloid angiopathy. We hypothesized that APOE ε4 carriers would gain greater therapeutic benefit from genetically reduced FXI levels compared to non-carriers. Methods: We conducted a two-stage Mendelian randomization (MR) analysis using the random-effects, inverse-variance weighted method. First, we estimated the effect of genetically proxied FXI inhibition on IS and ICH risk in the general population using summary data from genome-wide association studies of FXI levels (16,169 participants), IS (1,503,898 controls and 110,182 cases), and ICH (3,745 controls and 3,226 cases). Second, we performed stratified analyses to estimate the effect of genetically determined FXI levels on IS (10,343 cases and 476,838 controls) and ICH (2,236 cases and 484,945 controls) risk across APOE ε4 carriership strata (0, 1, or 2 alleles) using UK Biobank data. Results: In the general population, random-effects, inverse-variance weighted MR analyses showed that every 1 unit decrease in natural log-transformed FXI levels was associated with a 37% reduction in IS risk (OR:0.63; 95%CI:0.52–0.77; p <0.001) without a significant increase in ICH risk (OR:0.86; 95%CI:0.37–2.00; p =0.73). Stratified MR analyses indicated that genetically determined reductions in FXI levels had varying protective effects on IS risk based on APOE ε4 status: 31% in non-carriers (OR:0.69, 95%CI:0.53–0.91; p =0.008), 43% in carriers of 1 allele (OR:0.57, 95%CI:0.36–0.91; p =0.02), and 75% in carriers of 2 alleles (OR:0.25, 95%CI:0.06–1.06; p =0.06). Similar MR analyses showed no significant increase in ICH risk with genetically determined reductions in FXI levels in any APOE ε4 strata (all p >0.38, Figure 1). Conclusion: This two-stage genetic study provides causal evidence that lower FXI levels reduce IS risk in the general population, with an even stronger effect among APOE ε4 carriers, while not increasing ICH risk. These results indicate that FXI inhibitors might be a safer and more effective alternative to other anticoagulants among APOE ε4 carriers, who are known to be at higher risk for both ischemic and hemorrhagic events.

AbstractBackgroundIdentifying individuals’ levels of tau PET pathology could prove to be beneficial in clinical settings, given that emerging therapies aimed reducing Aβ seem to be most effective in these individuals. Here, we present the cases of four patients who visited the memory clinic at the University of Pittsburgh Medical Center between June and December 2023 and underwent both Aβ and tau‐PET scans.MethodThese individuals had standard clinical and cognitive outcomes, typical blood tests order in patients with memory impairment, MRI, and, as part of the HEAD study, PET PIB Aβ and two tau PET tracers (MK6240 and Flortaucipir).ResultAll patients presented a primary complaint of progressive memory decline. The results of their blood count, metabolic panel, TSH, and vitamin B12 tests were unremarkable. Patient 1 had a normal MRI, while Patients 2‐4 exhibited mild ischemic changes (Table 1). All patients tested positive for amyloid PET, supporting the diagnosis of AD. However, their tau PET results varied. Patients 1 (MOCA = 6) and 3 (MOCA =19), who were demented with impaired Instrumental Activities of Daily Living (IADL), tested positive for tau PET with Braak stages V‐VI using both tau PET tracers. Conversely, the mild cognitive impairment (MCI) Patients 2 (MOCA = 19) and 5 (MOCA = 29, neuropsych evaluation indicating MCI), who exhibited low tau levels, tested positive for MK6240 but negative for FTP.ConclusionAll four patients exhibited symptoms and signs consistent with typical amnestic AD presentation, which were confirmed using Aβ PET. Aβ PET presented a similar pattern across all individuals (Figure 1). Tau PET demonstrated greater variability, with lower levels in less cognitively impaired patients. Although tau PET can potentially be useful in identifying individuals in the earliest stages that would benefit from Aβ‐lowering therapies, this small series did not exclude that a low MOCA score combined with Aβ PET could achieve a similar outcome. Larger samples in real‐world clinical contexts are necessary to identify individuals with discrepancies between tau PET uptake and cognitive tests. This would reinforce the need for tau PET markers as complementary tests, singularly capable of identifying individuals across various biological stages to indicate therapies in clinical practice.

Abstract Senescent cells drive tissue dysfunction through the senescence-associated secretory phenotype (SASP). We uncovered a central role for mitochondria in the epigenetic regulation of the SASP, where mitochondrial-derived metabolites, specifically citrate and acetyl-CoA, fuel histone acetylation at SASP gene loci, promoting their expression. We identified the mitochondrial citrate carrier (SLC25A1) and ATP-citrate lyase (ACLY) as critical for this process. Inhibiting these pathways selectively suppresses SASP without affecting cell cycle arrest, highlighting their potential as therapeutic targets for age-related inflammation. Notably, SLC25A1 inhibition reduces systemic inflammation and extends healthspan in aged mice, establishing mitochondrial metabolism as pivotal to the epigenetic control of aging.

Abstract Mass spectrometry (MS) is a technique widely employed for the identification and characterization of proteins, with personalized medicine, systems biology, and biomedical applications. The application of MS-based proteomics advances our understanding of protein function, cellular signaling, and complex biological systems. MS data analysis is a critical process that includes identifying and quantifying proteins and peptides and then exploring their biological functions in downstream analyses. To address the complexities associated with MS data analysis, we developed ProtPipe to streamline and automate the processing and analysis of high-throughput proteomics and peptidomics datasets with DIA-NN preinstalled. The pipeline facilitates data quality control, sample filtering, and normalization, ensuring robust and reliable downstream analyses. ProtPipe provides downstream analyses, including protein and peptide differential abundance identification, pathway enrichment analysis, protein–protein interaction analysis, and major histocompatibility complex (MHC)–peptide binding affinity analysis. ProtPipe generates annotated tables and visualizations by performing statistical post-processing and calculating fold changes between predefined pairwise conditions in an experimental design. It is an open-source, well-documented tool available at https://github.com/NIH-CARD/ProtPipe, with a user-friendly web interface.

Study Design. Literature review and institutional analysis. Objective. This review examines the potential advantages of awake spinal surgery under neuroaxial anesthesia in minimizing positioning-related complications compared with traditional general anesthesia. Summary of Background Data. Spinal surgeries performed in the prone position under general anesthesia are associated with perioperative complications, such as ocular injury and vision loss, nerve damage, and pressure ulcers. Materials and Methods. A comprehensive literature search was conducted for articles published from 1986 to 2023 focusing on awake spinal surgery and positioning-related complications. In addition, insights from the Mayo Clinic team were incorporated to assess the potential benefits of awake spine surgery. Results. The review identified several positioning-related complications associated with prone positioning during spine surgery, including perioperative visual loss, neuropathies, pressure ulcers, and intra-abdominal hypertension leading to systemic cardiovascular effects and potential organ dysfunction. Advances at the Mayo Clinic have enabled the use of awake spinal surgery under neuroaxial anesthesia for complex procedures such as robotic transforaminal lumbar interbody fusion. The use of awake lumbar spine surgery has demonstrated advantages, including reduced positioning-related complications, immediate patient feedback to avoid harmful maneuvers, shorter operating room times, and improved hemodynamic stability. Conclusions. Awake lumbar spine surgery offers notable advantages in reducing positioning-related complications and presents a promising alternative to general anesthesia.

Abstract Protease activated receptor 2 (PAR2) is a G-protein coupled receptor expressed in meningeal neurons, fibroblasts and mast cells that may be targeted to treat migraine. MEDI0618, a fully humanized PAR2 monoclonal antibody, engineered to enhance FcRn-dependent recycling and currently in clinical development, was evaluated in human and rodent in vitro assays, in multiple murine in vivo migraine models and in a model of post-traumatic headache. MEDI0618 bound specifically and with high affinity to cells expressing human PAR2 (hPAR2) and prevented matriptase-induced increase in cytosolic calcium. Similarly, MEDI0618 prevented matriptase-induced calcium in primary fibroblasts and microvascular endothelial cells from human dura mater. MEDI0618 had no effect on hPAR1 receptors. Single-cell calcium imaging of acutely dissociated mouse trigeminal ganglion neurons confirmed expression and functionality of mouse PAR2. Studies in vivo used evoked cutaneous allodynia as a surrogate of headache-like pain and, in some experiments, rearing as a measure of non-evoked headache pain. MEDI0618 was administered subcutaneously to C57BL6/J female mice prior to induction of migraine-like pain with (i) systemic nitroglycerin or compound 48/80 (mast cell degranulator); or (ii) with supradural compound 48/80 or an inflammatory mediator (IM) cocktail. To assess possible efficacy against CGRP receptor (CGRP-R)-independent pain, MEDI0618 was also evaluated in the IM model in animals pretreated with systemic olcegepant (CGRP-R antagonist). Migraine-like pain was also induced by inhalational umbellulone, a TRPA1 agonist, in animals primed with restraint stress in the presence or absence of MEDI0618 as well as in a model of post-traumatic headache pain induced by a mild traumatic brain injury. MEDI0618 prevented cutaneous allodynia elicited by systemic nitroglycerin, compound 48/80 and from supradural compound 48/80 and IM. Systemic olcegepant completely blocked periorbital cutaneous allodynia induced by supradural CGRP but failed to reduce IM-induced cutaneous allodynia. In contrast, MEDI0618 fully prevented IM-induced cutaneous allodynia, regardless of pretreatment with olcegepant. Umbellulone elicited cutaneous allodynia only in restraint stress-primed animals, which was prevented by MEDI0618. MEDI0618 prevented the decrease in rearing behaviour elicited by compound 48/80. However, MEDI0618 did not prevent mild traumatic brain injury-related post-traumatic headache measures. These data indicate that MEDI0618 is a potent and selective inhibitor of PAR2 that is effective in human and rodent in vitro cell systems. Further, blockade of PAR2 with MEDI0618 was effective in all preclinical migraine models studied but not in a model of post-traumatic headache. MEDI0618 may represent a novel therapy for migraine prevention with activity against CGRP-dependent and independent attacks.