ABSTRACT
Multiple sclerosis (MS) is a demyelinating central nervous system (CNS) disorder that is associated with functional impairment and accruing disability. There are multiple U.S. Food and Drug Administration (FDA)-approved drugs that effectively dampen inflammation and slow disability progression. However, these agents do not work well for all patients and are associated with side effects that may limit their use. The vagus nerve (VN) provides a direct communication conduit between the CNS and the periphery, and modulation of the inflammatory reflex via electrical stimulation of the VN (VNS) shows efficacy in ameliorating pathology in several CNS and autoimmune disorders. We therefore investigated the impact of VNS in a rat experimental autoimmune encephalomyelitis (EAE) model of MS. In this study, VNS-mediated neuroimmune modulation is demonstrated to effectively decrease EAE disease severity and duration, infiltration of neutrophils and pathogenic lymphocytes, myelin damage, blood-brain barrier disruption, fibrinogen deposition, and proinflammatory microglial activation. VNS modulates expression of genes that are implicated in MS pathogenesis, as well as those encoding myelin proteins and transcription factors regulating new myelin synthesis. Together, these data indicate that neuroimmune modulation via VNS may be a promising approach to treat MS, that not only ameliorates symptoms but potentially also promotes myelin repair (remyelination).
Subject(s)
Encephalomyelitis, Autoimmune, Experimental , Multiple Sclerosis , Vagus Nerve Stimulation , Vagus Nerve , Animals , Encephalomyelitis, Autoimmune, Experimental/therapy , Encephalomyelitis, Autoimmune, Experimental/immunology , Rats , Multiple Sclerosis/therapy , Multiple Sclerosis/immunology , Multiple Sclerosis/pathology , Vagus Nerve Stimulation/methods , Inflammation/therapy , Inflammation/pathology , Disease Models, Animal , Female , Myelin Sheath/metabolism , Blood-Brain BarrierABSTRACT
BACKGROUND: Medical students are increasingly seeking out research opportunities to build their skills and network with future colleagues. Medical student-led conferences are an excellent endeavor to achieve this goal. METHODS: The American Association of Neurological Surgeons student chapter at the Donald and Barbara Zucker School of Medicine at Hofstra/Northwell designed an in-person medical student research symposium alongside the Northwell Health Department of Neurosurgery. Postconference feedback forms were sent out digitally to student attendees to evaluate event planning and execution and responses were given on a scale of 1-5 (5 being the highest score). RESULTS: In December 2023, the Northeast Medical Student Research Symposium was held with over 80 participants and 52 medical student presenters. Keynote speakers delivered lectures geared toward students interested in neurosurgery and neuroscience research, followed by an interactive poster board session and resident/attending networking dinner. After the conference, students affirmed that they learned more about neuroscience research after the event (mean: 4.3), were more inclined to attend other neuroscience research events in the future (mean: 4.7), and would attend this event if held next year (mean: 4.8). The poster sessions (mean: 4.75) and keynote lectures (mean: 5) were the highest rated events, while the resident/attending networking dinner (mean: 3.6) was a potential area for improvement. CONCLUSIONS: Regional in-person conferences are an excellent way to foster interest in neurosurgery and neuroscience research, network with like-minded peers, and prepare students for presentations at national meetings.
ABSTRACT
BACKGROUND: Key to the advancement of the field of bioelectronic medicine is the identification of novel pathways of neural regulation of immune function. Sensory neurons (termed nociceptors) recognize harmful stimuli and initiate a protective response by eliciting pain and defensive behavior. Nociceptors also interact with immune cells to regulate host defense and inflammatory responses. However, it is still unclear whether nociceptors participate in regulating primary IgG antibody responses to novel antigens. METHODS: To understand the role of transient receptor potential vanilloid 1 (TRPV1)-expressing neurons in IgG responses, we generated TRPV1-Cre/Rosa-ChannelRhodopsin2 mice for precise optogenetic activation of TRPV1 + neurons and TRPV1-Cre/Lox-diphtheria toxin A mice for targeted ablation of TRPV1-expressing neurons. Antigen-specific antibody responses were longitudinally monitored for 28 days. RESULTS: Here we show that TRPV1 expressing neurons are required to develop an antigen-specific immune response. We demonstrate that selective optogenetic stimulation of TRPV1+ nociceptors during immunization significantly enhances primary IgG antibody responses to novel antigens. Further, mice rendered deficient in TRPV1- expressing nociceptors fail to develop primary IgG antibody responses to keyhole limpet hemocyanin or haptenated antigen. CONCLUSION: This functional and genetic evidence indicates a critical role for nociceptor TRPV1 in antigen-specific primary antibody responses to novel antigens. These results also support consideration of potential therapeutic manipulation of nociceptor pathways using bioelectronic devices to enhance immune responses to foreign antigens.
ABSTRACT
BACKGROUND: The vagus nerve plays an important role in neuroimmune interactions and in the regulation of inflammation. A major source of efferent vagus nerve fibers that contribute to the regulation of inflammation is the brainstem dorsal motor nucleus of the vagus (DMN), as recently shown using optogenetics. In contrast to optogenetics, electrical neuromodulation has broad therapeutic implications. However, the anti-inflammatory effectiveness of electrical stimulation of the DMN (eDMNS) and the possible heart rate (HR) alterations associated with this approach have not been investigated. Here, we examined the effects of eDMNS on HR and cytokine levels in mice administered with lipopolysaccharide (LPS, endotoxin) and in mice subjected to cecal ligation and puncture (CLP) sepsis. METHODS: Anesthetized male 8-10-week-old C57BL/6 mice on a stereotaxic frame were subjected to eDMNS using a concentric bipolar electrode inserted into the left or right DMN or sham stimulation. eDMNS (500, 250 or 50 µA at 30â¯Hz, for 1â¯min) was performed and HR recorded. In endotoxemia experiments, sham or eDMNS utilizing 250 µA or 50 µA was performed for 5 mins and was followed by LPS (0.5â¯mg/kg) i.p. administration. eDMNS was also applied in mice with cervical unilateral vagotomy or sham operation. In CLP experiments sham or left eDMNS was performed immediately post CLP. Cytokines and corticosterone were analyzed 90 mins after LPS administration or 24â¯h after CLP. CLP survival was monitored for 14â¯days. RESULTS: Either left or right eDMNS at 500 µA and 250 µA decreased HR, compared with baseline pre-stimulation. This effect was not observed at 50 µA. Left side eDMNS at 50 µA, compared with sham stimulation, significantly decreased serum and splenic levels of the pro-inflammatory cytokine TNF and increased serum levels of the anti-inflammatory cytokine IL-10 during endotoxemia. The anti-inflammatory effect of eDMNS was abrogated in mice with unilateral vagotomy and was not associated with serum corticosterone alterations. Right side eDMNS in endotoxemic mice suppressed serum TNF and increased serum IL-10 levels but had no effects on splenic cytokines. In mice with CLP, left side eDMNS suppressed serum IL-6, as well as splenic IL-6 and increased splenic IL-10 and significantly improved the survival rate of CLP mice. CONCLUSIONS: For the first time we show that a regimen of eDMNS which does not cause bradycardia alleviates LPS-induced inflammation. These eDMNS anti-inflammatory effects require an intact vagus nerve and are not associated with corticosteroid alterations. eDMNS also decreases inflammation and improves survival in a model of polymicrobial sepsis. These findings are of interest for further studies exploring bioelectronic anti-inflammatory approaches targeting the brainstem DMN.
Subject(s)
Cytokines , Heart Rate , Inflammation , Lipopolysaccharides , Mice, Inbred C57BL , Sepsis , Vagus Nerve , Animals , Male , Mice , Heart Rate/physiology , Vagus Nerve/metabolism , Inflammation/metabolism , Sepsis/physiopathology , Sepsis/metabolism , Cytokines/metabolism , Electric Stimulation/methods , Vagus Nerve Stimulation/methods , Endotoxemia/physiopathology , Endotoxemia/metabolismABSTRACT
SUMMARY: The field of cancer neuroscience has begun to define the contributions of nerves to cancer initiation and progression; here, we highlight the future directions of basic and translational cancer neuroscience for malignancies arising outside of the central nervous system.
Subject(s)
Neoplasms , Neurosciences , Humans , Central Nervous System , Forecasting , ProteomicsABSTRACT
The pathogenic mechanisms of bacterial infections and resultant sepsis are partly attributed to dysregulated inflammatory responses sustained by some late-acting mediators including the procathepsin-L (pCTS-L). It was entirely unknown whether any compounds of the U.S. Drug Collection could suppress pCTS-L-induced inflammation, and pharmacologically be exploited into possible therapies. Here, we demonstrated that a macrophage cell-based screening of a U.S. Drug Collection of 1360 compounds resulted in the identification of progesterone (PRO) as an inhibitor of pCTS-L-mediated production of several chemokines [e.g., Epithelial Neutrophil-Activating Peptide (ENA-78), Monocyte Chemoattractant Protein-1 (MCP-1) or MCP-3] and cytokines [e.g., Interleukin-10 (IL-10) or Tumor Necrosis Factor (TNF)] in primary human peripheral blood mononuclear cells (PBMCs). In vivo, these PRO-entrapping 2,6-dimethal-ß-cyclodextrin (DM-ß-CD) nanoparticles (containing 1.35 mg/kg PRO and 14.65 mg/kg DM-ß-CD) significantly increased animal survival in both male (from 30% to 70%, n = 20, P = 0.041) and female (from 50% to 80%, n = 30, P = 0.026) mice even when they were initially administered at 24 h post the onset of sepsis. This protective effect was associated with a reduction of sepsis-triggered accumulation of three surrogate biomarkers [e.g., Granulocyte Colony Stimulating Factor (G-CSF) by 40%; Macrophage Inflammatory Protein-2 (MIP-2) by 45%; and Soluble Tumor Necrosis Factor Receptor I (sTNFRI) by 80%]. Surface Plasmon Resonance (SPR) analysis revealed a strong interaction between PRO and pCTS-L (KD = 78.2 ± 33.7 nM), which was paralleled with a positive correlation between serum PRO concentration and serum pCTS-L level (ρ = 0.56, P = 0.0009) or disease severity (Sequential Organ Failure Assessment, SOFA; ρ = 0.64, P = 0.0001) score in septic patients. Our observations support a promising opportunity to explore DM-ß-CD nanoparticles entrapping lipophilic drugs as possible therapies for clinical sepsis.
Subject(s)
Cathepsin L , Enzyme Precursors , Sepsis , beta-Cyclodextrins , Humans , Male , Female , Mice , Animals , Progesterone , Leukocytes, MononuclearSubject(s)
Delivery of Health Care , Humans , Health Equity , Healthcare Disparities , COVID-19/epidemiologyABSTRACT
Autonomic dysfunction is a clinical hallmark of infection caused by SARS-CoV-2, but the underlying mechanisms are unknown. The vagus nerve inflammatory reflex is an important, well-characterized mechanism for the reflexive suppression of cytokine storm, and its experimental or clinical impairment facilitates the onset and progression of hyperinflammation. Recent pathological evidence from COVID-19 victims reveals viral infection and inflammation in the vagus nerve and associated nuclei in the medulla oblongata. Although it has been suggested that vagus nerve inflammation in these patients mediates dysregulated respiration, whether it also contributes to dysfunction of the vagus nerve inflammatory reflex has not been addressed. Because lethality and tissue injury in acute COVID-19 are characterized by cytokine storm, it is plausible to consider evidence that impairment of the inflammatory reflex may contribute to overproduction of cytokines and resultant hyperinflammatory pathogenesis. Accordingly, here the authors discuss the inflammatory reflex, the consequences of its dysfunction in COVID-19, and whether there are opportunities for therapeutic intervention.
Subject(s)
COVID-19 , Humans , COVID-19/complications , SARS-CoV-2 , Cytokine Release Syndrome/etiology , Inflammation , Cytokines , Reflex/physiology , Vagus Nerve/physiologyABSTRACT
BACKGROUND: Choline acetyltransferase (ChAT) is required for the biosynthesis of acetylcholine, the molecular mediator that inhibits cytokine production in the cholinergic anti-inflammatory pathway of the vagus nerve inflammatory reflex. Abundant work has established the biology of cytoplasmic ChAT in neurons, but much less is known about the potential presence and function of ChAT in the extracellular milieu. OBJECTIVES: We evaluated the hypothesis that extracellular ChAT activity responds to inflammation and serves to inhibit cytokine release and attenuate inflammation. METHODS: After developing novel methods for quantification of ChAT activity in plasma, we determined whether ChAT activity changes in response to inflammatory challenges. RESULTS: Active ChAT circulates within the plasma compartment of mice and responds to immunological perturbations. Following the administration of bacterial endotoxin, plasma ChAT activity increases for 12-48 h, a time period that coincides with declining tumor necrosis factor (TNF) levels. Further, a direct activation of the cholinergic anti-inflammatory pathway by vagus nerve stimulation significantly increases plasma ChAT activity, whereas the administration of bioactive recombinant ChAT (r-ChAT) inhibits endotoxin-stimulated TNF production and anti-ChAT antibodies exacerbate endotoxin-induced TNF levels, results of which suggest that ChAT activity regulates endogenous TNF production. Administration of r-ChAT significantly attenuates pro-inflammatory cytokine production and disease activity in the dextran sodium sulfate preclinical model of inflammatory bowel disease. Finally, plasma ChAT levels are also elevated in humans with sepsis, with the highest levels observed in a patient who succumbed to infection. CONCLUSION: As a group, these results support further investigation of ChAT as a counter-regulator of inflammation and potential therapeutic agent.
Subject(s)
Acetylcholine , Choline O-Acetyltransferase , Humans , Choline O-Acetyltransferase/metabolism , Inflammation , Tumor Necrosis Factor-alpha/metabolism , Cytokines , EndotoxinsABSTRACT
BACKGROUND: Acute pancreatitis is a common and serious inflammatory condition currently lacking disease modifying therapy. The cholinergic anti-inflammatory pathway (CAP) is a potent protective anti-inflammatory response activated by vagus nerve-dependent α7 nicotinic acetylcholine receptor (α7nAChR) signaling using splenic CD4+ T cells as an intermediate. Activating the CAP ameliorates experimental acute pancreatitis. Galantamine is an acetylcholinesterase inhibitor (AChEI) which amplifies the CAP via modulation of central muscarinic ACh receptors (mAChRs). However, as mAChRs also activate pancreatitis, it is currently unknown whether galantamine would be beneficial in acute pancreatitis. METHODS: The effect of galantamine (1-6 mg/kg-body weight) on caerulein-induced acute pancreatitis was evaluated in mice. Two hours following 6 hourly doses of caerulein (50 µg/kg-body weight), organ and serum analyses were performed with accompanying pancreatic histology. Experiments utilizing vagotomy, gene knock out (KO) technology and the use of nAChR antagonists were also performed. RESULTS: Galantamine attenuated pancreatic histologic injury which was mirrored by a reduction in serum amylase and pancreatic inflammatory cytokines and an increase the anti-inflammatory cytokine IL-10 in the serum. These beneficial effects were not altered by bilateral subdiaphragmatic vagotomy, KO of either choline acetyltransferase+ T cells or α7nAChR, or administration of the nAChR ganglionic blocker mecamylamine or the more selective α7nAChR antagonist methyllycaconitine. CONCLUSION: Galantamine improves acute pancreatitis via a mechanism which does not involve previously established physiological and molecular components of the CAP. As galantamine is an approved drug in widespread clinical use with an excellent safety record, our findings are of interest for further evaluating the potential benefits of this drug in patients with acute pancreatitis.
Subject(s)
Galantamine , Pancreatitis , Humans , Mice , Animals , Galantamine/pharmacology , Galantamine/therapeutic use , alpha7 Nicotinic Acetylcholine Receptor/metabolism , Acetylcholinesterase/metabolism , Acetylcholinesterase/therapeutic use , Ceruletide/metabolism , Ceruletide/therapeutic use , Acute Disease , Pancreatitis/drug therapy , Pancreatitis/pathology , Cytokines/metabolism , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/therapeutic use , Body WeightABSTRACT
Chronic low-grade inflammation has been recognized as an underlying event linking obesity to cardiovascular disease (CVD). However, inflammatory alterations in individuals who are overweight remain understudied. To provide insight, we determined the levels of key circulating biomarkers of endotoxemia and inflammation, including lipopolysaccharide-binding protein (LBP), CRP, IL-6, leptin, and adiponectin in adult female subjects (n = 20) who were lean or overweight and had high cholesterol and/or high blood pressure - two important conventional risk factors for CVD. Plasma levels of LBP (a recognized marker of metabolic endotoxemia in obesity) were significantly higher in the overweight group compared with the lean group (P = 0.005). The levels of CRP, a general marker of inflammation, were also significantly higher in overweight subjects (P = 0.01), as were IL-6 (P = 0.02) and leptin (P = 0.002), pro-inflammatory mediators associated with cardiovascular risk. Levels of adiponectin, an adipokine with anti-inflammatory and anti-atherogenic functions, were significantly lower in the overweight group (P = 0.002). The leptin/adiponectin ratio, a preferential atherogenic marker was significantly increased in women who are overweight (P = 0.02). LBP, CRP, leptin, and adiponectin levels significantly correlated with BMI, but not with age. These results reveal the presence of subclinical endotoxemia and a pro-inflammatory state in overweight women and are of interest for further studies with the goal for improved understanding of women's cardiovascular health.
ABSTRACT
BACKGROUND: Vagus nerve stimulation is an investigational anti-inflammatory therapy targeting the nervous system to modulate immune activity. This study evaluated the efficacy and safety of transcutaneous auricular VNS (ta-VNS) in patients with pediatric-onset Crohn's disease (CD) or ulcerative colitis (UC). METHODS: Participants were 10-21 years of age with mild/moderate CD or UC and fecal calprotectin (FC) > 200 ug/g within 4 weeks of study entry. Subjects were randomized to receive either ta-VNS targeting the cymba conchae of the external left ear, or sham stimulation, of 5 min duration once daily for a 2-week period, followed by a cross over to the alternative stimulation for an additional 2 weeks. At week 4, all subjects received ta-VNS of 5 min duration twice daily until week 16. Primary study endpoints were clinical remission, and a ≥ 50% reduction in FC level from baseline to week 16. Heart rate variability measurements and patient-reported outcome questionnaires were completed during interval and week 16 assessments. RESULTS: Twenty-two subjects were enrolled and analyzed (10 CD, 12 UC). Six of 10 with CD had a wPCDAI > 12.5 and 6/12 with UC had a PUCAI > 10 at baseline, correlating to mild to moderate symptom activity. Among the 12 subjects with active symptomatic disease indices at baseline, clinical remission was achieved in 3/6 (50%) with CD and 2/6 (33%) with UC at week 16. Despite all subjects having FC levels ≥ 200 within 4 weeks of enrollment, five subjects (4 UC, 1 CD) had FC levels < 200 at the baseline visit and were excluded from the FC analysis. Of the remaining 17, median baseline FC was 907 µg/g (IQR 411-2,120). At week 16, 11/17 (64.7%) of those with baseline FC ≥ 200 had a ≥ 50% reduction in FC (95% CI 38.3-85.8). In the UC subjects, there was an 81% median reduction in FC vs baseline (833 µg/g; p = 0.03) while in the CD subjects, median reduction in FC at 16 weeks was 51% (357 µg/g; p = 0.09). There were no safety concerns. CONCLUSION: Noninvasive ta-VNS attenuated signs and symptoms in a pediatric cohort with mild to moderate inflammatory bowel disease. TRIAL REGISTRATION: NCT03863704-Date of registration 3/4/2019.
ABSTRACT
The emerging field of bioelectronic medicine (BEM) is poised to make a significant impact on the treatment of several neurological and inflammatory disorders. With several BEM therapies being recently approved for clinical use and others in late-phase clinical trials, the 2022 BEM summit was a timely scientific meeting convening a wide range of experts to discuss the latest developments in the field. The BEM Summit was held over two days in New York with more than thirty-five invited speakers and panelists comprised of researchers and experts from both academia and industry. The goal of the meeting was to bring international leaders together to discuss advances and cultivate collaborations in this emerging field that incorporates aspects of neuroscience, physiology, molecular medicine, engineering, and technology. This Meeting Report recaps the latest findings discussed at the Meeting and summarizes the main developments in this rapidly advancing interdisciplinary field. Our hope is that this Meeting Report will encourage researchers from academia and industry to push the field forward and generate new multidisciplinary collaborations that will form the basis of new discoveries that we can discuss at the next BEM Summit.
ABSTRACT
BACKGROUND AND AIMS: Crohn's disease [CD] is a debilitating, inflammatory condition affecting the gastrointestinal tract. There is no cure and sustained clinical and endoscopic remission is achieved by fewer than half of patients with current therapies. The immunoregulatory function of the vagus nerve, the 'inflammatory reflex', has been established in patients with rheumatoid arthritis and biologic-naive CD. The aim of this study was to explore the safety and efficacy of vagus nerve stimulation in patients with treatment-refractory CD, in a 16-week, open-label, multicentre, clinical trial. METHODS: A vagus nerve stimulator was implanted in 17 biologic drug-refractory patients with moderately to severely active CD. One patient exited the study pre-treatment, and 16 patients were treated with vagus nerve stimulation [4/16 receiving concomitant biologics] during 16 weeks of induction and 24 months of maintenance treatment. Endpoints included clinical improvement, patient-reported outcomes, objective measures of inflammation [endoscopic/molecular], and safety. RESULTS: There was a statistically significant and clinically meaningful decrease in CD Activity Index at Week 16 [meanâ ±â SD: -86.2â ±â 92.8, pâ =â 0.003], a significant decrease in faecal calprotectin [-2923â ±â 4104, pâ =â 0.015], a decrease in mucosal inflammation in 11/15 patients with paired endoscopies [-2.1â ±â 1.7, pâ =â 0.23], and a decrease in serum tumour necrosis factor and interferon-γ [46-52%]. Two quality-of-life indices improved in 7/11 patients treated without biologics. There was one study-related severe adverse event: a postoperative infection requiring device explantation. CONCLUSIONS: Neuroimmune modulation via vagus nerve stimulation was generally safe and well tolerated, with a clinically meaningful reduction in clinical disease activity associated with endoscopic improvement, reduced levels of faecal calprotectin and serum cytokines, and improved quality of life.
Subject(s)
Biological Products , Crohn Disease , Vagus Nerve Stimulation , Humans , Crohn Disease/drug therapy , Prospective Studies , Quality of Life , Vagus Nerve Stimulation/adverse effects , Remission Induction , Inflammation , Biological Products/therapeutic use , Leukocyte L1 Antigen ComplexABSTRACT
Background: The vagus nerve plays an important role in neuroimmune interactions and in the regulation of inflammation. A major source of efferent vagus nerve fibers that contribute to the regulation of inflammation is the brainstem dorsal motor nucleus of the vagus (DMN) as recently shown using optogenetics. In contrast to optogenetics, electrical neuromodulation has broad therapeutic implications, but the anti-inflammatory efficacy of electrical DMN stimulation (eDMNS) was not previously investigated. Here, we examined the effects of eDMNS on heart rate (HR) and cytokine levels in murine endotoxemia as well as the cecal ligation and puncture (CLP) model of sepsis. Methods: Anesthetized male 8-10-week-old C57BL/6 mice on a stereotaxic frame were subjected to eDMNS using a concentric bipolar electrode inserted into the left or right DMN or sham stimulation. eDMNS (50, 250 or 500 µA and 30 Hz, for 1 min) was performed and HR recorded. In endotoxemia experiments, sham or eDMNS utilizing 250 µA or 50 µA was performed for 5 mins and was followed by LPS (0.5 mg/kg) i.p. administration. eDMNS was also applied in mice with cervical unilateral vagotomy or sham operation. In CLP experiments sham or left eDMNS was performed immediately post CLP. Cytokines and corticosterone were analyzed 90 mins after LPS administration or 24h after CLP. CLP survival was monitored for 14 days. Results: Either left or right eDMNS at 250 µA and 500 µA decreased HR, compared with pre- and post-stimulation. This effect was not observed at 50 µA. Left side eDMNS at 50 µA, compared with sham stimulation, significantly decreased serum and splenic levels of the pro-inflammatory cytokine TNF and increased serum levels of the anti-inflammatory cytokine IL-10 during endotoxemia. The anti-inflammatory effect of eDMNS was abrogated in mice with unilateral vagotomy and were not associated with serum corticosterone alterations. Right side eDMNS suppressed serum TNF levels but had no effects on serum IL-10 and on splenic cytokines. In mice with CLP, left side eDMNS suppressed serum TNF and IL-6, as well as splenic IL-6 and increased splenic IL-10 and significantly improved the survival rate of CLP mice. Conclusions: For the first time we show that a regimen of eDMNS which does not cause bradycardia alleviates LPS-induced inflammation and these effects require an intact vagus nerve and are not associated with corticosteroid alterations. eDMNS also decreases inflammation and improves survival in a model of polymicrobial sepsis. These findings are of interest for further studies exploring bioelectronic anti-inflammatory approaches targeting the brainstem DMN.
ABSTRACT
Chronic low-grade inflammation has been recognized as an underlying event linking obesity to cardiovascular disease (CVD). However, inflammatory alterations in individuals who are overweight remain understudied. To provide insight, we determined the levels of key circulating biomarkers of endotoxemia and inflammation, including lipopolysaccharide-binding protein (LBP), CRP, IL-6, leptin, and adiponectin in adult female subjects (n=40) who were lean or overweight and had high cholesterol and/or high blood pressure - two important conventional risk factors for CVD. Plasma levels of LBP were significantly higher in the overweight group compared with the lean group (P=0.005). The levels of CRP were also significantly higher in overweight subjects (P=0.01), as were IL-6 (P=0.02) and leptin (P=0.002), pro-inflammatory mediators associated with cardiovascular risk. Levels of adiponectin, an adipokine with anti-inflammatory and anti-atherogenic functions, were significantly lower in the overweight group (P=0.002). The leptin/adiponectin ratio, a preferential atherogenic marker was significantly increased in women who are overweight (P=0.02). LBP, CRP, leptin, and adiponectin levels significantly correlated with BMI, but not with age and there was a significant correlation between LBP and IL-6 levels. These results reveal the presence of subclinical endotoxemia and a pro-inflammatory state in overweight women and are of interest for further studies with the goal for improved understanding of cardiovascular health risks in women.
ABSTRACT
Deficiency of coagulation factor VIII in hemophilia A disrupts clotting and prolongs bleeding. While the current mainstay of therapy is infusion of factor VIII concentrates, inhibitor antibodies often render these ineffective. Because preclinical evidence shows electrical vagus nerve stimulation accelerates clotting to reduce hemorrhage without precipitating systemic thrombosis, we reasoned it might reduce bleeding in hemophilia A. Using two different male murine hemorrhage and thrombosis models, we show vagus nerve stimulation bypasses the factor VIII deficiency of hemophilia A to decrease bleeding and accelerate clotting. Vagus nerve stimulation targets acetylcholine-producing T lymphocytes in spleen and α7 nicotinic acetylcholine receptors (α7nAChR) on platelets to increase calcium uptake and enhance alpha granule release. Splenectomy or genetic deletion of T cells or α7nAChR abolishes vagal control of platelet activation, thrombus formation, and bleeding in male mice. Vagus nerve stimulation warrants clinical study as a therapy for coagulation disorders and surgical or traumatic bleeding.
Subject(s)
Hemophilia A , Thrombosis , Vagus Nerve Stimulation , Mice , Male , Animals , Hemophilia A/complications , Hemophilia A/therapy , alpha7 Nicotinic Acetylcholine Receptor/genetics , Blood Platelets , Hemorrhage/therapy , Vagus NerveABSTRACT
Introduction: Inflammation is an inherently self-amplifying process, resulting in progressive tissue damage when unresolved. A brake on this positive feedback system is provided by the nervous system which has evolved to detect inflammatory signals and respond by activating anti-inflammatory processes, including the cholinergic anti-inflammatory pathway mediated by the vagus nerve. Acute pancreatitis, a common and serious condition without effective therapy, develops when acinar cell injury activates intrapancreatic inflammation. Prior study has shown that electrical stimulation of the carotid sheath, which contains the vagus nerve, boosts the endogenous anti-inflammatory response and ameliorates acute pancreatitis, but it remains unknown whether these anti-inflammatory signals originate in the brain. Methods: Here, we used optogenetics to selectively activate efferent vagus nerve fibers originating in the brainstem dorsal motor nucleus of the vagus (DMN) and evaluated the effects on caerulein-induced pancreatitis. Results: Stimulation of the cholinergic neurons in the DMN significantly attenuates the severity of pancreatitis as indicated by reduced serum amylase, pancreatic cytokines, tissue damage, and edema. Either vagotomy or silencing cholinergic nicotinic receptor signaling by pre-administration of the antagonist mecamylamine abolishes the beneficial effects. Discussion: These results provide the first evidence that efferent vagus cholinergic neurons residing in the brainstem DMN can inhibit pancreatic inflammation and implicate the cholinergic anti-inflammatory pathway as a potential therapeutic target for acute pancreatitis.