Mechanisms and Therapeutic Relevance of Neuro-immune Communication

Immunotherapy in the context of sepsis-induced immunological dysregulation

Sepsis is a clinical syndrome caused by uncontrollable immune dysregulation triggered by pathogen infection, characterized by high incidence, mortality rates, and disease burden. Current treatments primarily focus on symptomatic relief, lacking specific therapeutic interventions. The core mechanism of sepsis is believed to be an imbalance in the host's immune response, characterized by early excessive inflammation followed by late immune suppression, triggered by pathogen invasion. This suggests that we can develop immunotherapeutic treatment strategies by targeting and modulating the components and immunological functions of the host's innate and adaptive immune systems. Therefore, this paper reviews the mechanisms of immune dysregulation in sepsis and, based on this foundation, discusses the current state of immunotherapy applications in sepsis animal models and clinical trials.

Interactions and Trends of Interleukins, PAI-1, CRP, and TNF-α in Inflammatory Responses during the Perioperative Period of Joint Arthroplasty: Implications for Pain Management-A Narrative Review

Inflammation during the perioperative period of joint arthroplasty is a critical aspect of patient outcomes, influencing both the pathophysiology of pain and the healing process. This narrative review comprehensively evaluates the roles of specific cytokines and inflammatory biomarkers in this context and their implications for pain management. Inflammatory responses are initiated and propagated by cytokines, which are pivotal in the development of both acute and chronic postoperative pain. Pro-inflammatory cytokines play essential roles in up-regulating the inflammatory response, which, if not adequately controlled, leads to sustained pain and impaired tissue healing. Anti-inflammatory cytokines work to dampen inflammatory responses and promote resolution. Our discussion extends to the genetic and molecular influences on cytokine production, which influence pain perception and recovery rates post-surgery. Furthermore, the role of PAI-1 in modulating inflammation through its impact on the fibrinolytic system highlights its potential as a therapeutic target. The perioperative modulation of these cytokines through various analgesic and anesthetic techniques, including the fascia iliac compartment block, demonstrates a significant reduction in pain and inflammatory markers, thus underscoring the importance of targeted therapeutic strategies. Our analysis suggests that a nuanced understanding of the interplay between pro-inflammatory and anti-inflammatory cytokines is required. Future research should focus on individualized pain management strategies.

Neuroimmune modulation by tryptophan derivatives in neurological and inflammatory disorders

The nervous and immune systems are highly developed, and each performs specialized physiological functions. However, they work together, and their dysfunction is associated with various diseases. Specialized molecules, such as neurotransmitters, cytokines, and more general metabolites, are essential for the appropriate regulation of both systems. Tryptophan, an essential amino acid, is converted into functional molecules such as serotonin and kynurenine, both of which play important roles in the nervous and immune systems. The role of kynurenine metabolites in neurodegenerative and psychiatric diseases has recently received particular attention. Recently, we found that hyperactivity of the kynurenine pathway is a critical risk factor for septic shock. In this review, we first outline neuroimmune interactions and tryptophan derivatives and then summarized the changes in tryptophan metabolism in neurological disorders. Finally, we discuss the potential of tryptophan derivatives as therapeutic targets for neuroimmune disorders.

IL-8 (CXCL8) Correlations with Psychoneuroimmunological Processes and Neuropsychiatric Conditions

Interleukin-8 (IL-8/CXCL8), an essential CXC chemokine, significantly influences psychoneuroimmunological processes and affects neurological and psychiatric health. It exerts a profound effect on immune cell activation and brain function, suggesting potential roles in both neuroprotection and neuroinflammation. IL-8 production is stimulated by several factors, including reactive oxygen species (ROS) known to promote inflammation and disease progression. Additionally, CXCL8 gene polymorphisms can alter IL-8 production, leading to potential differences in disease susceptibility, progression, and severity across populations. IL-8 levels vary among neuropsychiatric conditions, demonstrating sensitivity to psychosocial stressors and disease severity. IL-8 can be detected in blood circulation, cerebrospinal fluid (CSF), and urine, making it a promising candidate for a broad-spectrum biomarker. This review highlights the need for further research on the diverse effects of IL-8 and the associated implications for personalized medicine. A thorough understanding of its complex role could lead to the development of more effective and personalized treatment strategies for neuropsychiatric conditions.

Autophagy, a double-edged sword for oral tissue regeneration

BACKGROUND

Oral health is of fundamental importance to maintain systemic health in humans. Stem cell-based oral tissue regeneration is a promising strategy to achieve the recovery of impaired oral tissue. As a highly conserved process of lysosomal degradation, autophagy induction regulates stem cell function physiologically and pathologically. Autophagy activation can serve as a cytoprotective mechanism in stressful environments, while insufficient or over-activation may also lead to cell function dysregulation and cell death.

AIM OF REVIEW

This review focuses on the effects of autophagy on stem cell function and oral tissue regeneration, with particular emphasis on diverse roles of autophagy in different oral tissues, including periodontal tissue, bone tissue, dentin pulp tissue, oral mucosa, salivary gland, maxillofacial muscle, temporomandibular joint, etc. Additionally, this review introduces the molecular mechanisms involved in autophagy during the regeneration of different parts of oral tissue, and how autophagy can be regulated by small molecule drugs, biomaterials, exosomes/RNAs or other specific treatments. Finally, this review discusses new perspectives for autophagy manipulation and oral tissue regeneration.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Overall, this review emphasizes the contribution of autophagy to oral tissue regeneration and highlights the possible approaches for regulating autophagy to promote the regeneration of human oral tissue.

Vagus nerve stimulation modulates distinct acetylcholine receptors on B cells and limits the germinal center response

Acetylcholine is produced in the spleen in response to vagus nerve activation; however, the effects on antibody production have been largely unexplored. Here, we use a chronic vagus nerve stimulation (VNS) mouse model to study the effect of VNS on T-dependent B cell responses. We observed lower titers of high-affinity IgG and fewer antigen-specific germinal center (GC) B cells. GC B cells from chronic VNS mice exhibited altered mRNA and protein expression suggesting increased apoptosis and impaired plasma cell differentiation. Follicular dendritic cell (FDC) cluster dispersal and altered gene expression suggested poor function. The absence of acetylcholine-producing CD4+ T cells diminished these alterations. In vitro studies revealed that α7 and α9 nicotinic acetylcholine receptors (nAChRs) directly regulated B cell production of TNF, a cytokine crucial to FDC clustering. α4 nAChR inhibited coligation of CD19 to the B cell receptor, presumably decreasing B cell survival. Thus, VNS-induced GC impairment can be attributed to distinct effects of nAChRs on B cells.

Dominant mechanism in spinal cord injury-induced immunodeficiency syndrome (SCI-IDS): sympathetic hyperreflexia

Clinical studies have shown that individuals with spinal cord injury (SCI) are particularly susceptible to infectious diseases, resulting in a syndrome called SCI-induced immunodeficiency syndrome (SCI-IDS), which is the leading cause of death after SCI. It is believed that SCI-IDS is associated with exaggerated activation of sympathetic preganglionic neurons (SPNs). After SCI, disruption of bulbospinal projections from the medulla oblongata C1 neurons to the SPNs results in the loss of sympathetic inhibitory modulation from the brain and brainstem and the occurrence of abnormally high levels of spinal sympathetic reflexes (SSR), named sympathetic hyperreflexia. As the post-injury survival time lengthens, mass recruitment and anomalous sprouting of excitatory interneurons within the spinal cord result in increased SSR excitability, resulting in an excess sympathetic output that disrupts the immune response. Therefore, we first analyze the structural underpinnings of the spinal cord-sympathetic nervous system-immune system after SCI, then demonstrate the progress in highlighting mechanisms of SCI-IDS focusing on norepinephrine (NE)/Beta 2-adrenergic receptor (β2-AR) signal pathways, and summarize recent preclinical studies examining potential means such as regulating SSR and inhibiting β2-AR signal pathways to improve immune function after SCI. Finally, we present research perspectives such as to promote the effective regeneration of C1 neurons to rebuild the connection of C1 neurons with SPNs, to regulate excitable or inhibitory interneurons, and specifically to target β2-AR signal pathways to re-establish neuroimmune balance. These will help us design effective strategies to reverse post-SCI sympathetic hyperreflexia and improve the overall quality of life for individuals with SCI.

Electrical stimulation of the dorsal motor nucleus of the vagus in male mice can regulate inflammation without affecting the heart rate

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 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 24 h after CLP. CLP survival was monitored for 14 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.

Alleviating effect of vagus nerve cutting in Salmonella-induced gut infections and anxiety-like behavior via enhancing microbiota-derived GABA

The vagus nerve, a pivotal link within the gut-brain axis, plays a critical role in maintaining homeostasis and mediating communication between the gastrointestinal tract and the brain. It has been reported that gastrointestinal infection by Salmonella typhimurium (S. typhimurium) triggers gut inflammation and manifests as anxiety-like behaviors, yet the mechanistic involvement of the vagus nerve remains to be elucidated. In this study, we demonstrated that unilateral cervical vagotomy markedly attenuated anxiety-like behaviors induced by S. typhimurium SL1344 infection in C57BL/6 mice, as evidenced by the open field test and marble burying experiment. Furthermore, vagotomy significantly diminished neuronal activation within the nucleus of the solitary tract and amygdala, alongside mitigating aberrant glial cell activation in the hippocampus and amygdala. Additionally, vagotomy notably decreases serum endotoxin levels, counters the increase in splenic Salmonella concentration, and modulates the expression of inflammatory cytokines-including IL-6, IL-1β, and TNF-α-in both the gastrointestinal tract and brain, with a concurrent reduction in IL-22 and CXCL1 expression. This intervention also fostered the enrichment of beneficial gut microbiota, including Alistipes and Lactobacillus species, and augmented the production of gamma-aminobutyric acid (GABA) in the gut. Administration of GABA replicated the vagotomy's beneficial effects on reducing gut inflammation and anxiety-like behavior in infected mice. However, blockade of GABA receptors with picrotoxin abrogated the vagotomy's protective effects against gut inflammation, without influencing its impact on anxiety-like behaviors. Collectively, these findings suggest that vagotomy exerts a protective effect against infection by promoting GABA synthesis in the colon and alleviating anxiety-like behavior. This study underscores the critical role of the vagus nerve in relaying signals of gut infection to the brain and posits that targeting the gut-brain axis may offer a novel and efficacious approach to preventing gastrointestinal infections and associated behavioral abnormalities.

BDNF in Neuropathic Pain; the Culprit that Cannot be Apprehended

In males but not in females, brain derived neurotrophic factor (BDNF) plays an obligatory role in the onset and maintenance of neuropathic pain. Afferent terminals of injured peripheral nerves release colony stimulating factor (CSF-1) and other mediators into the dorsal horn. These transform the phenotype of dorsal horn microglia such that they express P2X4 purinoceptors. Activation of these receptors by neuron-derived ATP promotes BDNF release. This microglial-derived BDNF increases synaptic activation of excitatory dorsal horn neurons and decreases that of inhibitory neurons. It also alters the neuronal chloride gradient such the normal inhibitory effect of GABA is converted to excitation. By as yet undefined processes, this attenuated inhibition increases NMDA receptor function. BDNF also promotes the release of pro-inflammatory cytokines from astrocytes. All of these actions culminate in the increase dorsal horn excitability that underlies many forms of neuropathic pain. Peripheral nerve injury also alters excitability of structures in the thalamus, cortex and mesolimbic system that are responsible for pain perception and for the generation of co-morbidities such as anxiety and depression. The weight of evidence from male rodents suggests that this preferential modulation of excitably of supra-spinal pain processing structures also involves the action of microglial-derived BDNF. Possible mechanisms promoting the preferential release of BDNF in pain signaling structures are discussed. In females, invading T-lymphocytes increase dorsal horn excitability but it remains to be determined whether similar processes operate in supra-spinal structures. Despite its ubiquitous role in pain aetiology neither BDNF nor TrkB receptors represent potential therapeutic targets.

Electroacupuncture alleviates intestinal inflammation via a distinct neuro-immune signal pathway in the treatment of postoperative ileus

BACKGROUND

The induction of intestinal inflammation as a result of abdominal surgery is an essential factor in postoperative ileus (POI) development. Electroacupuncture (EA) at ST36 has been demonstrated to relieve intestinal inflammation and restore gastrointestinal dysmotility in POI. This study aims to elucidate the neuroimmune pathway involved in the anti-inflammatory properties of EA in POI.

METHODS

After intestinal manipulation (IM) was performed to induce POI, intestinal inflammation and motility were assessed 24 h post-IM, by evaluating gastrointestinal transit (GIT), cytokines expression, and leukocyte infiltration. Experimental surgery, pharmacological intervention, and genetic knockout mice were used to elucidate the neuroimmune mechanisms of EA.

RESULTS

EA at ST36 significantly improved GIT and reduced the expression of pro-inflammatory cytokines and leukocyte infiltration in the intestinal muscularis following IM in mice. The anti-inflammatory effectiveness of EA treatment was abolished by sub-diaphragmatic vagotomy, whereas splenectomy did not hinder the anti-inflammatory benefits of EA treatment. The hexamethonium chloride (HEX) administration contributes to a notable reduction in the EA capacity to suppress inflammation and enhance motility dysfunction, and EA is ineffective in α7 nicotinic acetylcholine receptor (α7nAChR) knockout mice.

CONCLUSIONS

EA at ST36 prevents intestinal inflammation and dysmotility through a neural circuit that requires vagal innervation but is independent of the spleen. Further findings revealed that the process involves enteric neurons mediating the vagal signal and requires the presence of α7nAChR. These findings suggest that utilizing EA at ST36 may represent a possible therapeutic approach for POI and other immune-related gastrointestinal diseases.

Navigating the blurred path of mixed neuroimmune signaling

Evolution has created complex mechanisms to sense environmental danger and protect tissues, with the nervous and immune systems playing pivotal roles. These systems work together, coordinating local and systemic reflexes to restore homeostasis in response to tissue injury and infection. By sharing receptors and ligands, they influence the pathogenesis of various diseases. Recently, a less-explored aspect of neuroimmune communication has emerged: the release of neuropeptides from immune cells and cytokines/chemokines from sensory neurons. This article reviews evidence of this unique neuroimmune interplay and its impact on the development of allergy, inflammation, itch, and pain. We highlight the effects of this neuroimmune signaling on vital processes such as host defense, tissue repair, and inflammation resolution, providing avenues for exploration of the underlying mechanisms and therapeutic potential of this signaling.

Epigenetic regulation of microglia and neurons by proinflammatory signaling following adolescent intermittent ethanol (AIE) exposure and in human AUD

Adolescent alcohol drinking is linked to high rates of adult alcohol problems and alcohol use disorder (AUD). The Neurobiology of Alcohol Drinking in Adulthood (NADIA) consortium adolescent intermittent ethanol (AIE) models adolescent binge drinking, followed by abstinent maturation to adulthood to determine the persistent AIE changes in neurobiology and behavior. AIE increases adult alcohol drinking and preference, increases anxiety and reward seeking, and disrupts sleep and cognition, all risks for AUD. In addition, AIE induces changes in neuroimmune gene expression in neurons and glia that alter neurocircuitry and behavior. HMGB1 is a unique neuroimmune signal released from neurons and glia by ethanol that activates multiple proinflammatory receptors, including Toll-like receptors (TLRs), that spread proinflammatory gene induction. HMGB1 expression is increased by AIE in rat brain and in post-mortem human AUD brain, where it correlates with lifetime alcohol consumption. HMGB1 activation of TLR increase TLR expression. Human AUD brain and rat brain following AIE show increases in multiple TLRs. Brain regional differences in neurotransmitters and cell types impact ethanol responses and neuroimmune gene induction. Microglia are monocyte-like cells that provide trophic and synaptic functions, that ethanol proinflammatory signals sensitize or "prime" during repeated drinking cycles, impacting neurocircuitry. Neurocircuits are differently impacted dependent upon neuronal-glial signaling. Acetylcholine is an anti-inflammatory neurotransmitter. AIE increases HMGB1-TLR4 signaling in forebrain, reducing cholinergic neurons by silencing multiple cholinergic defining genes through upregulation of RE-1 silencing factor (REST), a transcription inhibitor known to regulate neuronal differentiation. HMGB1 REST induction reduces cholinergic neurons in basal forebrain and cholinergic innervation of hippocampus. Adult brain hippocampal neurogenesis is regulated by a neurogenic niche formed from multiple cells. In vivo AIE and in vitro studies find ethanol increases HMGB1-TLR4 signaling and other proinflammatory signaling as well as reducing trophic factors, NGF, and BDNF, coincident with loss of the cholinergic synapse marker vChAT. These changes in gene expression-transcriptomes result in reduced adult neurogenesis. Excitingly, HMGB1 antagonists, anti-inflammatories, and epigenetic modifiers like histone deacetylase inhibitors restore trophic the neurogenesis. These findings suggest anti-inflammatory and epigenetic drugs should be considered for AUD therapy and may provide long-lasting reversal of psychopathology.

Frequency, kinetics and determinants of viable SARS-CoV-2 in bioaerosols from ambulatory COVID-19 patients infected with the Beta, Delta or Omicron variants

Airborne transmission of SARS-CoV-2 aerosol remains contentious. Importantly, whether cough or breath-generated bioaerosols can harbor viable and replicating virus remains largely unclarified. We performed size-fractionated aerosol sampling (Andersen cascade impactor) and evaluated viral culturability in human cell lines (infectiousness), viral genetics, and host immunity in ambulatory participants with COVID-19. Sixty-one percent (27/44) and 50% (22/44) of participants emitted variant-specific culture-positive aerosols <10μm and <5μm, respectively, for up to 9 days after symptom onset. Aerosol culturability is significantly associated with lower neutralizing antibody titers, and suppression of transcriptomic pathways related to innate immunity and the humoral response. A nasopharyngeal Ct <17 rules-in ~40% of aerosol culture-positives and identifies those who are probably highly infectious. A parsimonious three transcript blood-based biosignature is highly predictive of infectious aerosol generation (PPV > 95%). There is considerable heterogeneity in potential infectiousness i.e., only 29% of participants were probably highly infectious (produced culture-positive aerosols <5μm at ~6 days after symptom onset). These data, which comprehensively confirm variant-specific culturable SARS-CoV-2 in aerosol, inform the targeting of transmission-related interventions and public health containment strategies emphasizing improved ventilation.

Advances and Challenges in Sepsis Management: Modern Tools and Future Directions

Sepsis, a critical condition marked by systemic inflammation, profoundly impacts both innate and adaptive immunity, often resulting in lymphopenia. This immune alteration can spare regulatory T cells (Tregs) but significantly affects other lymphocyte subsets, leading to diminished effector functions, altered cytokine profiles, and metabolic changes. The complexity of sepsis stems not only from its pathophysiology but also from the heterogeneity of patient responses, posing significant challenges in developing universally effective therapies. This review emphasizes the importance of phenotyping in sepsis to enhance patient-specific diagnostic and therapeutic strategies. Phenotyping immune cells, which categorizes patients based on clinical and immunological characteristics, is pivotal for tailoring treatment approaches. Flow cytometry emerges as a crucial tool in this endeavor, offering rapid, low cost and detailed analysis of immune cell populations and their functional states. Indeed, this technology facilitates the understanding of immune dysfunctions in sepsis and contributes to the identification of novel biomarkers. Our review underscores the potential of integrating flow cytometry with omics data, machine learning and clinical observations to refine sepsis management, highlighting the shift towards personalized medicine in critical care. This approach could lead to more precise interventions, improving outcomes in this heterogeneously affected patient population.

Role of pattern recognition receptors in chemotherapy-induced neuropathic pain

Progress in the development of effective chemotherapy is producing a growing population of patients with acute and chronic painful chemotherapy-induced peripheral neuropathy (CIPN), a serious treatment-limiting side effect for which there is currently no US Food and Drug Administration-approved treatment. CIPNs induced by diverse classes of chemotherapy drugs have remarkably similar clinical presentations, leading to the suggestion they share underlying mechanisms. Sensory neurons share with immune cells the ability to detect damage associated molecular patterns (DAMPs), molecules produced by diverse cell types in response to cellular stress and injury, including by chemotherapy drugs. DAMPs, in turn, are ligands for pattern recognition receptors (PRRs), several of which are found on sensory neurons, as well as satellite cells, and cells of the immune system. In the present experiments, we evaluated the role of two PRRs, TLR4 and RAGE, present in dorsal root ganglion (DRG), in CIPN. Antisense (AS)-oligodeoxynucleotides (ODN) against TLR4 and RAGE mRNA were administered intrathecally before ('prevention protocol') or 3 days after ('reversal protocol') the last administration of each of three chemotherapy drugs that treat cancer by different mechanisms (oxaliplatin, paclitaxel and bortezomib). TLR4 and RAGE AS-ODN prevented the development of CIPN induced by all three chemotherapy drugs. In the reversal protocol, however, while TLR4 AS-ODN completely reversed oxaliplatin- and paclitaxel-induced CIPN, in rats with bortezomib-induced CIPN it only produced a temporary attenuation. RAGE AS-ODN, in contrast, reversed CIPN induced by all three chemotherapy drugs. When a TLR4 antagonist was administered intradermally to the peripheral nociceptor terminal, it did not affect CIPN induced by any of the chemotherapy drugs. However, when administered intrathecally, to the central terminal, it attenuated hyperalgesia induced by all three chemotherapy drugs, compatible with a role of TLR4 in neurotransmission at the central terminal but not sensory transduction at the peripheral terminal. Finally, since it has been established that cultured DRG neurons can be used to study direct effects of chemotherapy on nociceptors, we also evaluated the role of TLR4 in CIPN at the cellular level, using patch-clamp electrophysiology in DRG neurons cultured from control and chemotherapy-treated rats. We found that increased excitability of small-diameter DRG neurons induced by in vivo and in vitro exposure to oxaliplatin is TLR4-dependent. Our findings suggest that in addition to the established contribution of PRR-dependent neuroimmune mechanisms, PRRs in DRG cells also have an important role in CIPN.

Somatosensory cortex and central amygdala regulate neuropathic pain-mediated peripheral immune response via vagal projections to the spleen

Pain involves neuroimmune crosstalk, but the mechanisms of this remain unclear. Here we showed that the splenic T helper 2 (TH2) immune cell response is differentially regulated in male mice with acute versus chronic neuropathic pain and that acetylcholinergic neurons in the dorsal motor nucleus of the vagus (AChDMV) directly innervate the spleen. Combined in vivo recording and immune cell profiling revealed the following two distinct circuits involved in pain-mediated peripheral TH2 immune response: glutamatergic neurons in the primary somatosensory cortex (GluS1HL)→AChDMV→spleen circuit and GABAergic neurons in the central nucleus of the amygdala (GABACeA)→AChDMV→spleen circuit. The acute pain condition elicits increased excitation from GluS1HL neurons to spleen-projecting AChDMV neurons and increased the proportion of splenic TH2 immune cells. The chronic pain condition increased inhibition from GABACeA neurons to spleen-projecting AChDMV neurons and decreased splenic TH2 immune cells. Our study thus demonstrates how the brain encodes pain-state-specific immune responses in the spleen.

Permissive role of vascular endothelium in fibrosis: focus on the kidney

Fibrosis, the morphologic end-result of a plethora of chronic conditions and the scorch for organ function, has been thoroughly investigated. One aspect of its development and progression, namely the permissive role of vascular endothelium, has been overshadowed by studies into (myo)fibroblasts and TGF-β; thus, it is the subject of the present review. It has been established that tensile forces of the extracellular matrix acting on cells are a prerequisite for mechanochemical coupling, leading to liberation of TGF-β and formation of myofibroblasts. Increased tensile forces are prompted by elevated vascular permeability in response to diverse stressors, resulting in the exudation of fibronectin, fibrinogen/fibrin, and other proteins, all stiffening the extracellular matrix. These processes lead to the development of endothelial cells dysfunction, endothelial-to-mesenchymal transition, premature senescence of endothelial cells, perturbation of blood flow, and gradual obliteration of microvasculature, leaving behind "string" vessels. The resulting microvascular rarefaction is not only a constant companion of fibrosis but also an adjunct mechanism of its progression. The deepening knowledge of the above chain of pathogenetic events involving endothelial cells, namely increased permeability-stiffening of the matrix-endothelial dysfunction-microvascular rarefaction-tissue fibrosis, may provide a roadmap for therapeutic interventions deemed to curtail and reverse fibrosis.

M1 cholinergic signaling in the brain modulates cytokine levels and splenic cell sub-phenotypes following cecal ligation and puncture

BACKGROUND

The contribution of the central nervous system to sepsis pathobiology is incompletely understood. In previous studies, administration of endotoxin to mice decreased activity of the vagus anti-inflammatory reflex. Treatment with the centrally-acting M1 muscarinic acetylcholine (ACh) receptor (M1AChR) attenuated this endotoxin-mediated change. We hypothesize that decreased M1AChR-mediated activity contributes to inflammation following cecal ligation and puncture (CLP), a mouse model of sepsis.

METHODS

In male C57Bl/6 mice, we quantified basal forebrain cholinergic activity (immunostaining), hippocampal neuronal activity, serum cytokine/chemokine levels (ELISA) and splenic cell subtypes (flow cytometry) at baseline, following CLP and following CLP in mice also treated with the M1AChR agonist xanomeline.

RESULTS

At 48 h. post-CLP, activity in basal forebrain cells expressing choline acetyltransferase (ChAT) was half of that observed at baseline. Lower activity was also noted in the hippocampus, which contains projections from ChAT-expressing basal forebrain neurons. Serum levels of TNFα, IL-1β, MIP-1α, IL-6, KC and G-CSF were higher post-CLP than at baseline. Post-CLP numbers of splenic macrophages and inflammatory monocytes, TNFα+ and ILβ+ neutrophils and ILβ+ monocytes were higher than baseline while numbers of central Dendritic Cells (cDCs), CD4+ and CD8+ T cells were lower. When, following CLP, mice were treated with xanomeline activity in basal forebrain ChAT-expressing neurons and in the hippocampus was significantly higher than in untreated animals. Post-CLP serum concentrations of TNFα, IL-1β, and MIP-1α, but not of IL-6, KC and G-CSF, were significantly lower in xanomeline-treated mice than in untreated mice. Post-CLP numbers of splenic neutrophils, macrophages, inflammatory monocytes and TNFα+ neutrophils also were lower in xanomeline-treated mice than in untreated animals. Percentages of IL-1β+ neutrophils, IL-1β+ monocytes, cDCs, CD4+ T cells and CD8+ T cells were similar in xanomeline-treated and untreated post-CLP mice.

CONCLUSION

Our findings indicate that M1AChR-mediated responses modulate CLP-induced alterations in serum levels of some, but not all, cytokines/chemokines and affected splenic immune response phenotypes.

Noninvasive Vagus Nerve Stimulation in Postural Tachycardia Syndrome: A Randomized Clinical Trial

BACKGROUND

Low-level transcutaneous stimulation of the auricular branch of the vagus nerve at the tragus is antiarrhythmic and anti-inflammatory in animals and humans. Preliminary studies show that transcutaneous vagus nerve stimulation (tVNS) is beneficial in animal models of postural tachycardia syndrome (POTS).

OBJECTIVES

In this study the authors conducted a sham-controlled, double-blind, randomized clinical trial to examine the effect of tVNS on POTS over a 2-month period relative to sham stimulation.

METHODS

tVNS (20 Hz, 1 mA below discomfort threshold) was delivered using an ear clip attached to either the tragus (active; n = 12) or the ear lobe (sham; n = 14) for 1 hour daily over a 2-month period. Postural tachycardia was assessed during the baseline and 2-month visit. Heart rate variability based on 5-minute electrocardiogram, serum cytokines, and antiautonomic autoantibodies were measured at the respective time points.

RESULTS

Mean age was 34 ± 11 years (100% female; 81% Caucasian). Adherence to daily stimulation was 83% in the active arm and 86% in the sham arm (P > 0.05). Postural tachycardia was significantly less in the active arm compared with the sham arm at 2 months (mean postural increase in heart rate 17.6 ± 9.9 beats/min vs 31.7 ± 14.4 beats/min; P = 0.01). Antiadrenergic autoantibodies and inflammatory cytokines were lower in the active arm compared with the sham arm at 2 months (P < 0.05). Heart rate variability was better in the active arm. No device-related side effects were observed.

CONCLUSIONS

Our results support the emerging paradigm of noninvasive neuromodulation to treat POTS. Mechanistically, this effect appears to be related to reduction of antiautonomic autoantibodies and inflammatory cytokines, and improvement in autonomic tone. Further studies are warranted. (Autoimmune Basis for Postural Tachycardia Syndrome; NCT05043051).

Interorgan communication networks in the kidney-lung axis

The homeostasis and health of an organism depend on the coordinated interaction of specialized organs, which is regulated by interorgan communication networks of circulating soluble molecules and neuronal connections. Many diseases that seemingly affect one primary organ are really multiorgan diseases, with substantial secondary remote organ complications that underlie a large part of their morbidity and mortality. Acute kidney injury (AKI) frequently occurs in critically ill patients with multiorgan failure and is associated with high mortality, particularly when it occurs together with respiratory failure. Inflammatory lung lesions in patients with kidney failure that could be distinguished from pulmonary oedema due to volume overload were first reported in the 1930s, but have been largely overlooked in clinical settings. A series of studies over the past two decades have elucidated acute and chronic kidney-lung and lung-kidney interorgan communication networks involving various circulating inflammatory cytokines and chemokines, metabolites, uraemic toxins, immune cells and neuro-immune pathways. Further investigations are warranted to understand these clinical entities of high morbidity and mortality, and to develop effective treatments.

No consistent evidence for the anti-inflammatory effect of vagus nerve stimulation in humans: A systematic review and meta-analysis

Vagus nerve stimulation (VNS) has been identified as an innovative immunosuppressive treatment strategy in rodent studies. However, its' clinical potential is still unclear. Therefore, we aimed to assess whether VNS can reduce inflammatory proteins and/or immune cells in humans, through a pre-registered systematic review and meta-analysis according to PRISMA guidelines. The databases Cochrane, Pubmed and World of Knowledge were searched in duplicate up to the 3rd of March 2022 and publications from identified clinical trial registrations were identified until 20th of August 2023. Studies were included if they provided peer-reviewed data for humans who received VNS as short-term (<=1 day) or long-term (>=2 days-365 days) stimulation and reported at least one cytokine or immune cell after treatment.Screening of title, abstract, full text, and data extraction was performed in duplicate by two independent reviewers. Data were pooled using a random-effects model and meta-regression was performed for moderating factors. Reporting bias was assessed. The standardized mean difference (Hedge's g) was used to indicate overall differences of cytokine data (mean and standard deviation or median and interquartile range at the study level) to test our a-priori hypothesis. The systematic review of 36 studies with 1135 participants (355 receiving a control/sham condition and 780 receiving VNS) revealed anti-inflammatory effects of VNS for cytokines in several reports, albeit often in subgroup analyses, but our meta-analyses of 26 studies did not confirm these findings. Although most cytokines were numerically reduced, the reduction did not reach statistical significance after VNS: not in the between-group comparisons (short-term: TNF-α: g = -0.21, p = 0.359; IL-6: g = -0.94, p = 0.112; long-term: TNF-α: g = -0.13, p = 0.196; IL-6: g = -0.67, p = 0.306); nor in the within-study designs (short-term: TNF-α: g = -0.45, p = 0.630; IL-6: g = 0.28, p = 0.840; TNF-α: g = -0.53, p = 0.297; IL-6:g = -0.02, p = 0.954). Only the subgroup analysis of 4 long-term studies with acute inflammation was significant: VNS decreased CRP significantly more than sham stimulation. Additional subgroup analyses including stimulation duration, stimulation method (invasive/non-invasive), immune stimulation, and study quality did not alter results. However, heterogeneity was high, and most studies had poor to fair quality. Given the low number of studies for each disease, a disease-specific analysis was not possible. In conclusion, while numeric effects were reported in individual studies, the current evidence does not substantiate the claim that VNS impacts inflammatory cytokines in humans. However, it may be beneficial during acute inflammatory events. To assess its full potential, high-quality studies and technological advances are required.

Cholinergic signaling via the α7 nicotinic acetylcholine receptor regulates the migration of monocyte-derived macrophages during acute inflammation

BACKGROUND

The involvement of the autonomic nervous system in the regulation of inflammation is an emerging concept with significant potential for clinical applications. Recent studies demonstrate that stimulating the vagus nerve activates the cholinergic anti-inflammatory pathway that inhibits pro-inflammatory cytokines and controls inflammation. The α7 nicotinic acetylcholine receptor (α7nAChR) on macrophages plays a key role in mediating cholinergic anti-inflammatory effects through a downstream intracellular mechanism involving inhibition of NF-κB signaling, which results in suppression of pro-inflammatory cytokine production. However, the role of the α7nAChR in the regulation of other aspects of the immune response, including the recruitment of monocytes/macrophages to the site of inflammation remained poorly understood.

RESULTS

We observed an increased mortality in α7nAChR-deficient mice (compared with wild-type controls) in mice with endotoxemia, which was paralleled with a significant reduction in the number of monocyte-derived macrophages in the lungs. Corroborating these results, fluorescently labeled α7nAChR-deficient monocytes adoptively transferred to WT mice showed significantly diminished recruitment to the inflamed tissue. α7nAChR deficiency did not affect monocyte 2D transmigration across an endothelial monolayer, but it significantly decreased the migration of macrophages in a 3D fibrin matrix. In vitro analysis of major adhesive receptors (L-selectin, β1 and β2 integrins) and chemokine receptors (CCR2 and CCR5) revealed reduced expression of integrin αM and αX on α7nAChR-deficient macrophages. Decreased expression of αMβ2 was confirmed on fluorescently labeled, adoptively transferred α7nAChR-deficient macrophages in the lungs of endotoxemic mice, indicating a potential mechanism for α7nAChR-mediated migration.

CONCLUSIONS

We demonstrate a novel role for the α7nAChR in mediating macrophage recruitment to inflamed tissue, which indicates an important new aspect of the cholinergic regulation of immune responses and inflammation.

Brain-Splenic Immune System Interactions in Hypertension: Cellular and Molecular Mechanisms

Hypertension represents a major worldwide cause of death and disability, and it is becoming increasingly clear that available therapies are not sufficient to reduce the risk of major cardiovascular events. Various mechanisms contribute to blood pressure increase: neurohormonal activation, autonomic nervous system imbalance, and immune activation. Of note, the brain is an important regulator of blood pressure levels; it recognizes the peripheral perturbation and organizes a reflex response by modulating immune system and hormonal release to attempt at restoring the homeostasis. The connection between the brain and peripheral organs is mediated by the autonomic nervous system, which also modulates immune and inflammatory responses. Interestingly, an increased autonomic nervous system activity has been correlated with an altered immune response in cardiovascular diseases. The spleen is the largest immune organ exerting a potent influence on the cardiovascular system during disease and is characterized by a dense noradrenergic innervation. Taken together, these aspects led to hypothesize a key role of neuroimmune mechanisms in the onset and progression of hypertension. This review discusses how the nervous and splenic immune systems interact and how the mechanisms underlying the neuroimmune cross talk influence the disease progression.

Autonomic and cytokine mechanisms of acute electroacupuncture in a rodent model of functional dyspepsia

BACKGROUND

Cytokines have been presumed to play an important role in the pathophysiology of functional dyspepsia (FD). Electroacupuncture (EA) has been used for FD treatment; however, its mechanisms remain largely unknown. This study aimed to (1) compare the plasma levels of cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10, in "FD" rats with normal control rats; (2) investigate whether EA, using chronically implanted electrodes, could inhibit the release of these cytokines; and (3) explore the correlation of cytokine levels with plasma norepinephrine (NE) levels and gastric emptying (GE).

METHODS

A rodent model of FD was established via neonatal treatment with intragastric iodoacetamide. After 8 weeks, the rats were implanted with electrodes at acupoint ST36 for EA. The plasma levels of cytokines and NE were measured using enzyme-linked immunosorbent assay. We explored the correlations of cytokine levels with NE levels and GE.

KEY RESULTS

(i) "FD" rats demonstrated increased levels of TNF-α, IL-1β, and IL-6 (p < 0.05 each) compared with the control rats. (ii) EA significantly decreased the plasma levels of TNF-α, IL-1β, and IL-6 in "FD" rats (p < 0.05 each) compared with sham EA. (iii) The plasma levels of NE were positively correlated with those of IL-6 (r = 0.86, p < 0.05) and IL-1β (r = 0.81, p < 0.05), whereas NE levels and GE were negatively correlated with IL-10 levels (r = -0.870, p < 0.05 and r = -0.791, p < 0.05, respectively).

CONCLUSIONS

EA inhibits the release of proinflammatory cytokines probably via the suppression of sympathetic activity in "FD" rats.

Clinical Significance and Immune Infiltration Analyses of a Novel Nerve-Related lncRNA Signature in Gastric Cancer

Gastric cancer (GC) is a progressive disease with high morbidity and mortality. Accumulating evidence indicated that nervous system-cancer crosstalk can affect the occurrence and progression of GC. However, the role of nerve-related lncRNAs (NRLs) in GC remains largely unexplored. In this study, a total of 441 nerve-related genes were collected from the KEGG database, and two approaches, unsupervised clustering and WGCNA, were employed to identify NRLs. Lasso regression analysis was then used to construct the nerve-related lncRNA signature (NRLS). Based on the expression profiles of 5 lncRNAs, we developed a stable NRLS to predict survival in GC patients, and survival analyses showed significantly shorter overall survival (OS) in patients with high NRLS. In addition, the NRLS was found to be positively correlated with immune characteristics, including tumor-infiltrating immune cells, immune modulators, cytokines and chemokines. We then analyzed the role of NRLS in predicting chemotherapy and immunotherapy responses, and constructed the OS nomogram combining NRLS and other clinical features. In conclusion, we constructed a robust NRLS model to stratify GC patients and predict the outcomes of chemotherapy and immunotherapy. This study can provide a new perspective for future individualized treatment of GC.

Transauricular nerve stimulation in acute ischaemic stroke requiring mechanical thrombectomy: Protocol for a phase 2A, proof-of-concept, sham-controlled randomised trial

BACKGROUND

Labile blood pressure after acute ischaemic stroke requiring mechanical thrombectomy is independently associated with poor patient outcomes.

OBJECTIVES

This study protocol describes is designed to determine whether transauricular nerve stimulation, improves baroreflex sensitivity, reduces blood pressure variability in the first 24 hours after acute ischaemic stroke requiring mechanical thrombectomy.

DESIGN: PHASE 2A, PROOF-OF-CONCEPT, SHAM-CONTROLLED RANDOMISED TRIAL

Methods and Analysis: 36 individuals undergoing mechanical thrombectomy for acute ischaemic stroke with established hypertension aged >18 years will be randomly allocated to receive bilateral active or sham transauricular nerve stimulation for the duration of the mechanical thrombectomy procedure (AffeX-CT/001 investigational device). The intervention will be repeated for 1h the morning following the mechanical thrombectomy. Non-invasive blood pressure will be measured ≥2h for 24h after mechanical thrombectomy. Holter electrocardiographic monitoring will be recorded during transauricular nerve stimulation. Participants, clinicians and investigators will be masked to treatment allocations. The primary outcome will be the coefficient of variation of systolic blood pressure. Secondary outcomes include additional estimates of blood pressure variability and time/frequency-domain measures of autonomic cardiac modulation An adjusted sample size of 36 patients is required to have a 90% chance of detecting, as significant at the 5% level, a difference in the coefficient of variation in systolic blood pressure of 5±4mmHg between sham and active stimulation [assuming 5% non-compliance rate in each group]. Ethics: confirmed on 16 March 2023 by HRA and Health and Care Research Wales ethics committee (reference 23/WA/0013).

DISCUSSION

This study will provide proof-of-concept data that examines whether non-invasive autonomic neuromodulation can be used to favourably modify blood pressure and autonomic control after acute ischaemic stroke requiring mechanical thrombectomy.

TRIAL REGISTRATION

Trial registration number: NCT05417009.

The role of neuroinflammation in the transition of acute to chronic pain and the opioid-induced hyperalgesia and tolerance

Current evidence suggests that activation of glial and immune cells leads to increased production of proinflammatory mediators, creating a neuroinflammatory state. Neuroinflammation has been proven to be a fundamental mechanism in the genesis of acute pain and its transition to neuropathic and chronic pain. A noxious event that stimulates peripheral afferent nerve fibers may also activate pronociceptive receptors situated at the dorsal root ganglion and dorsal horn of the spinal cord, as well as peripheral glial cells, setting off the so-called peripheral sensitization and spreading neuroinflammation to the brain. Once activated, microglia produce cytokines, chemokines, and neuropeptides that can increase the sensitivity and firing properties of second-order neurons, upregulating the signaling of nociceptive information to the cerebral cortex. This process, known as central sensitization, is crucial for chronification of acute pain. Immune-neuronal interactions are also implicated in the lesser-known complex regulatory relationship between pain and opioids. Current evidence suggests that activated immune and glial cells can alter neuronal function, induce, and maintain pathological pain, and disrupt the analgesic effects of opioid drugs by contributing to the development of tolerance and dependence, even causing paradoxical hyperalgesia. Such alterations may occur when the neuronal environment is impacted by trauma, inflammation, and immune-derived molecules, or when opioids induce proinflammatory glial activation. Hence, understanding these intricate interactions may help in managing pain signaling and opioid efficacy beyond the classical pharmacological approach.

Temporal dynamics of pro-inflammatory cytokines and serum corticosterone following acute sleep fragmentation in male mice

Obstructive sleep apnea is increasing worldwide, leading to disordered sleep patterns and inflammatory responses in brain and peripheral tissues that predispose individuals to chronic disease. Pro-inflammatory cytokines activate the inflammatory response and are normally regulated by glucocorticoids secreted from adrenal glands. However, the temporal dynamics of inflammatory responses and hypothalamic-pituitary-adrenal (HPA) axis activation in relation to acute sleep fragmentation (ASF) are undescribed. Male C57BL/6J mice were exposed to ASF or control conditions (no ASF) over specified intervals (1, 2, 6, or 24 h) and cytokine gene expression (IL-1β, TNF-α) in brain and peripheral tissues as well as serum glucocorticoid and interleukin-6 (IL-6) concentration were assessed. The HPA axis was rapidly activated, leading to elevated serum corticosterone from 1-24 h of ASF compared with controls. This activation was followed by elevated serum IL-6 concentration from 6-24 h of ASF. The tissue to first exhibit increased pro-inflammatory gene expression from ASF was heart (1 h of ASF). In contrast, pro-inflammatory gene expression was suppressed in hypothalamus from 1 h of ASF, but elevated at 6 h. Because the HPA axis was activated throughout ASF, this suggests that brain, but not peripheral, pro-inflammatory responses were rapidly inhibited by glucocorticoid immunosuppression.

Gut liver brain axis in diseases: the implications for therapeutic interventions

Gut-liver-brain axis is a three-way highway of information interaction system among the gastrointestinal tract, liver, and nervous systems. In the past few decades, breakthrough progress has been made in the gut liver brain axis, mainly through understanding its formation mechanism and increasing treatment strategies. In this review, we discuss various complex networks including barrier permeability, gut hormones, gut microbial metabolites, vagus nerve, neurotransmitters, immunity, brain toxic metabolites, β-amyloid (Aβ) metabolism, and epigenetic regulation in the gut-liver-brain axis. Some therapies containing antibiotics, probiotics, prebiotics, synbiotics, fecal microbiota transplantation (FMT), polyphenols, low FODMAP diet and nanotechnology application regulate the gut liver brain axis. Besides, some special treatments targeting gut-liver axis include farnesoid X receptor (FXR) agonists, takeda G protein-coupled receptor 5 (TGR5) agonists, glucagon-like peptide-1 (GLP-1) receptor antagonists and fibroblast growth factor 19 (FGF19) analogs. Targeting gut-brain axis embraces cognitive behavioral therapy (CBT), antidepressants and tryptophan metabolism-related therapies. Targeting liver-brain axis contains epigenetic regulation and Aβ metabolism-related therapies. In the future, a better understanding of gut-liver-brain axis interactions will promote the development of novel preventative strategies and the discovery of precise therapeutic targets in multiple diseases.

Neuroimmune interplay in kidney health and disease: Role of renal nerves

Renal nerves and their role in physiology and disease have been a topic of increasing interest in the past few decades. Renal inflammation contributes to many cardiorenal disease conditions, including hypertension, chronic kidney disease, and polycystic kidney disease. Much is known about the role of renal sympathetic nerves in physiology - they contribute to the regulation of sodium reabsorption, renin release, and renal vascular resistance. In contrast, far less is known about afferent, or "sensory," renal nerves, which convey signals from the kidney to the brain. While much remains unknown about these nerves in the context of normal physiology, even less is known about their contribution to disease states. Furthermore, it has become apparent that the crosstalk between renal nerves and the immune system may augment or modulate disease. Research from other fields, especially pain research, has provided critical insight into neuroimmune crosstalk. Sympathetic renal nerve activity may increase immune cell recruitment, but far less work has been done investigating the interplay between afferent renal nerves and the immune system. Evidence from other fields suggests that inflammation may augment afferent renal nerve activity. Furthermore, these nerves may exacerbate renal inflammation through the release of afferent-specific neurotransmitters.

Acute pancreatitis in intraductal papillary mucinous neoplasm: a single-center retrospective cohort study with systematic review and meta-analysis

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) is a cystic tumor of the pancreas arising from abnormal papillary proliferation of ductal epithelial cells, and is a precancerous lesion of pancreatic malignancy. This study aimed to evaluate associations between acute pancreatitis (AP) and histologic subtypes of IPMN.

METHODS

In the clinical study, patients with IPMN confirmed by surgical resection specimens at our institute between 2009 and 2021 were eligible for inclusion. Associations and predictive accuracy of AP on the presence of HGD were determined by logistic regressions. In addition, a systematic review and meta-analysis was conducted through literatures upon search in PubMed, Embase, CENTRAL, China National Knowledge Infrastructure (CKNI), and Wanfang database, up to June, 2023. Pooled effects of the associations between AP and HGD and intestinal epithelial subtype subtype, shown as odds ratios (ORs) with 95% confidence intervals (CIs), were calculated using random effects model.

RESULTS

The retrospective cohort study included 47 patients (32 males, 15 females) diagnosed with IPMN at our center between 2009 and 2021, including 11 cases with AP (median 62 years) and 36 cases (median 64.5 years) without. Accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of AP in predicting HGD were 78.7%, 57.1%, 82.5%, 36.4%, and 91.7%, respectively. Univariate logistic regression analysis showed that AP group had greater odds of presence of HGD (OR: 6.29,95% CI: 1.14-34.57) than non-AP group. Meta-analysis of five case-control studies in the literature included 930 patients and showed that AP-IPMN patients had higher odds for HGD (OR: 2.13, 95% CI 1.38-3.29) and intestinal epithelial subtype (OR: 5.38, 95% CI: 3.50-8.27) compared to non-AP IPMN.

CONCLUSIONS

AP is predictive of malignancy in patients with IPMN.

Evidence of extraganglionic vagal mechanoreceptors in the mouse vagus nerve

Vagal afferent neuronal somas are in the nodose and jugular ganglia. In this study, we identified extraganglionic neurons in whole-mount preparations of the vagus nerves from Phox2b-Cre-ZsGreen transgenic mice. These neurons are typically arranged in small clusters and monolayers along the cervical vagus nerve. Although infrequent, these neurons were sometimes observed along the thoracic and esophageal vagus. We performed RNAscope in situ hybridization and confirmed that the extraganglionic neurons detected in this transgenic mouse strain expressed vagal afferent markers (i.e., Phox2b and Slc17a6) as well as markers that identify them as potential gastrointestinal mechanoreceptors (i.e., Tmc3 and Glp1r). We also identified extraganglionic neurons in the vagus nerves of wild-type mice that were injected intraperitoneally with Fluoro-Gold, thereby ruling out possible anatomical discrepancies specific for transgenic mice. In wild-type mice, extraganglionic cells were positive for peripherin, confirming their neuronal nature. Taken together, our findings revealed a previously undiscovered population of extraganglionic neurons associated with the vagus nerve. Going forward, it is important to consider the possible existence of extraganglionic mechanoreceptors that transmit signals from the abdominal viscera in future studies related to vagal structure and function.

Alpha-1 adrenergic signaling drives cardiac regeneration via extracellular matrix remodeling transcriptional program in zebrafish macrophages

The autonomic nervous system plays a pivotal role in cardiac repair. Here, we describe the mechanistic underpinning of adrenergic signaling in fibrotic and regenerative response of the heart to be dependent on immunomodulation. A pharmacological approach identified adrenergic receptor alpha-1 as a key regulator of macrophage phenotypic diversification following myocardial damage in zebrafish. Genetic manipulation and single-cell transcriptomics showed that the receptor signals activation of an "extracellular matrix remodeling" transcriptional program in a macrophage subset, which serves as a key regulator of matrix composition and turnover. Mechanistically, adrenergic receptor alpha-1-activated macrophages determine activation of collagen-12-expressing fibroblasts, a cellular determinant of cardiac regenerative niche, through midkine-mediated paracrine crosstalk, allowing lymphatic and blood vessel growth and cardiomyocyte proliferation at the lesion site. These findings identify the mechanism of adrenergic signaling in macrophage phenotypic and functional determination and highlight the potential of neural modulation for regulation of fibrosis and coordination of myocardial regenerative response.

Role of ventrolateral part of ventromedial hypothalamus in post-myocardial infarction cardiac dysfunction induced by sympathetic nervous system

Psychological stress has been recognized as a contributing factor to worsened prognosis in patients with cardiac failure following myocardial infarction (MI). Although the ventrolateral part of the ventromedial hypothalamus (VMHVL) has been implicated in emotional distress, its involvement in post-MI cardiac dysfunction remains largely unexplored. This study was designed to investigate the effect of the VMHVL activation in the MI rat model and its underlying mechanisms. Our findings demonstrate that activation of VMHVL neurons enhances the activity of the cardiac sympathetic nervous system through the paraventricular nucleus (PVN) and superior cervical ganglion (SCG). This activation leads to an elevation in catecholamine levels, which subsequently modulates myosin function and triggers the release of anti-inflammatory factors, to exacerbate the post-MI cardiac prognosis. The denervation of the superior cervical ganglion (SGN) effectively blocked the cardiac sympathetic effects induced by the VMHVL activation, and ameliorated the cardia fibrosis and dysfunction. Therefore, our study identified the role of the "VMHVL-PVN-SCG" sympathetic pathway in the post-MI heart, and proposed SGN as a promising strategy in mitigating cardiac prognosis in stressful rats.

The Impact of the Nervous System on Arteries and the Heart: The Neuroimmune Cardiovascular Circuit Hypothesis

Three systemic biological systems, i.e., the nervous, the immune, and the cardiovascular systems, form a mutually responsive and forward-acting tissue network to regulate acute and chronic cardiovascular function in health and disease. Two sub-circuits within the cardiovascular system have been described, the artery brain circuit (ABC) and the heart brain circuit (HBC), forming a large cardiovascular brain circuit (CBC). Likewise, the nervous system consists of the peripheral nervous system and the central nervous system with their functional distinct sensory and effector arms. Moreover, the immune system with its constituents, i.e., the innate and the adaptive immune systems, interact with the CBC and the nervous system at multiple levels. As understanding the structure and inner workings of the CBC gains momentum, it becomes evident that further research into the CBC may lead to unprecedented classes of therapies to treat cardiovascular diseases as multiple new biologically active molecules are being discovered that likely affect cardiovascular disease progression. Here, we weigh the merits of integrating these recent observations in cardiovascular neurobiology into previous views of cardiovascular disease pathogeneses. These considerations lead us to propose the Neuroimmune Cardiovascular Circuit Hypothesis.

M1 Cholinergic Signaling Modulates Cytokine Levels and Splenocyte Sub-Phenotypes Following Cecal Ligation and Puncture

Background

The contribution of the central nervous system to sepsis pathobiology is incompletely understood. In previous studies, administration of endotoxin to mice decreased activity of the vagus anti-inflammatory reflex. Treatment with the centrally-acting M1/M4 muscarinic acetylcholine (ACh) receptor (M1/M4AChR) attenuated this endotoxin-mediated change. We hypothesize that decreased M1/M4AChR-mediated activity contributes to inflammation following cecal ligation and puncture (CLP), a mouse model of sepsis.

Methods

Basal forebrain cholinergic activity (immunostaining), serum cytokine/chemokine levels (ELISA) and splenocyte subtypes (flow cytometry) were examined at baseline and following CLP in male C57BL/6 male mice.

Rersults

At 48hrs. post-CLP, activity in basal forebrain cells expressing choline acetyltransferase (ChAT) was half of that observed at baseline. Lower activity was also noted in the hippocampus, which contains projections from ChAT-expressing basal forebrain neurons. Serum levels of TNFα, IL-1β, MIP-1α, IL-6, KC and G-CSF were higher post-CLP than at baseline. Post-CLP numbers of splenic macrophages and inflammatory monocytes, TNFa+ and ILb+ neutrophils and ILb+ monocytes were higher than baseline while numbers of central Dendritic Cells (cDCs), CD4+ and CD8+ T cells were lower. When, following CLP, mice were treated with xanomeline, a central-acting M1AChR agonist, activity in basal forebrain ChAT-expressing neurons and in the hippocampus was significantly higher than in untreated animals. Post-CLP serum concentrations of TNFα, IL-1β, and MIP-1α, but not of IL-6, KC and G-CSF, were significantly lower in xanomline-treated mice than in untreated mice. Post-CLP numbers of splenic neutrophils, macrophages, inflammatory monocytes and TNFα+ neutrophils also were lower in xanomeline-treated mice than in untreated animals. The effects of CLP on percentages of IL-1β+ neutrophils, IL-1β+ monocytes, cDCs, CD4+ T cells and CD8+ T cells were similar in xanomeline - treated and untreated post-CLP mice.

Conclusion

Our findings indicate that M1/M4AChR-mediated responses modulate CLP-induced alterations in the distribution of some, but not all, leukocyte phenotypes and certain cytokines and chemokines.

The Hepatic Nerves Regulated Inflammatory Effect in the Process of Liver Injury: Is Nerve the Key Treating Target for Liver Inflammation?

Liver injury is a common pathological basis for various liver diseases. Chronic liver injury is often an important initiating factor in liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Currently, hepatitis A and E infections are the most common causes of acute liver injury worldwide, whereas drug toxicity (paracetamol overdose) in the USA and part of Western Europe. In recent years, chronic liver injury has become a common disease that harms human health. Meanwhile, the main causes of chronic liver injury are viral hepatitis (B, C) and long-term alcohol consumption worldwide. During the process of liver injury, massive inflammatory cytokines are stimulated by these hazardous factors, leading to a systemic inflammatory response syndrome, followed by a compensatory anti-inflammatory response, which causes immune cell dysfunction and sepsis, subsequent multi-organ failure. Cytokine release and immune cell infiltration-mediated aseptic inflammation are the most important features of the pathobiology of liver failure. From this perspective, diminishing the onset and progression of liver inflammation is of clinical importance in the treatment of liver injury. Although many studies have hinted at the critical role of nerves in regulating inflammation, there largely remains undetermined how hepatic nerves mediate immune inflammation and how the inflammatory factors released by these nerves are involved in the process of liver injury. Therefore, the purpose of this article is to summarize previous studies in the field related to hepatic nerve and inflammation as well as future perspectives on the aforementioned questions. Our findings were presented in three aspects: types of nerve distribution in the liver, how these nerves regulate immunity, and the role of liver nerves in hepatitis and liver failure.

SLC10A3 Is a Prognostic Biomarker and Involved in Immune Infiltration and Programmed Cell Death in Lower Grade Glioma

BACKGROUND

The association between SLC10A3 (solute carrier family 10 member 3) and lower grade glioma (LGG) remains unclear.

METHODS

We used public databases and bioinformatics analysis to analyze SLC10A3. These included The Cancer Genome Atlas, Genotype-Tissue Expansion, Chinese Glioma Genome Atlas, Human Protein Atlas, GeneCards, cBioPortal, Search Tool for the Retrieval of Interacting Genes/Proteins, Gene Expression Profiling Interactive Analysis, Tumor Immune Estimation Resource, Tumor-Immune System Interaction Database, receiver operating characteristic curve analysis, Kaplan-Meier analysis, Cox analysis, nomograms, calibration plots, gene ontology/Kyoto Encyclopedia of Genes and Genomes enrichment analysis, gene set enrichment analysis, single-sample gene set enrichment analysis, and Spearman's correlation analysis.

RESULTS

SLC10A3 was upregulated in adrenocortical carcinoma, glioblastoma, and LGG and was associated with good overall survival (OS) in adrenocortical carcinoma and poor OS in LGG and glioblastoma. SLC10A3 was increased with increased World Health Organization grade, upregulated in isocitrate dehydrogenase-wild type, 1p/19q (chromosome arms 1p and 19q) non-co-deleted, and higher in astrocytoma. Patients with LGG were grouped by the occurrence of the clinical outcome endpoints (i.e., OS, disease-specific survival [DSS], and progression-free interval events). Genetic alterations in SLC10A3 were associated with poor progression-free survival in LGG. Most of clinical characteristics were associated with the SLC10A3 expression level. SLC10A3 with diagnostic and prognostic value (OS, DSS, and progression-free interval) was an independent prognostic factor in LGG. Moreover, Nomograms (WHO grade, 1p/19q codeletion, age and SLC10A3) had moderately accurate predictive for OS and DSS. Functional analysis showed that SLC10A3 might participate in the transport of multiple substances, neurogenic signaling, immune response, and programmed cell death in LGG. SLC10A3 correlated with immune infiltration in LGG and moderately correlated with the gene signature of pyroptosis, lysosome-dependent cell death, necroptosis, apoptosis, ferroptosis, alkaliptosis, and autophagy-dependent cell death.

CONCLUSIONS

SLC10A3 is a potential diagnostic and prognostic biomarker for LGG and might be associated with substance transport, neurogenic signaling, immune infiltration, and programmed cell death in LGG.

Protective Application of Chinese Herbal Compounds and Formulae in Intestinal Inflammation in Humans and Animals

Intestinal inflammation is a chronic gastrointestinal disorder with uncertain pathophysiology and causation that has significantly impacted both the physical and mental health of both people and animals. An increasing body of research has demonstrated the critical role of cellular signaling pathways in initiating and managing intestinal inflammation. This review focuses on the interactions of three cellular signaling pathways (TLR4/NF-κB, PI3K-AKT, MAPKs) with immunity and gut microbiota to explain the possible pathogenesis of intestinal inflammation. Traditional medicinal drugs frequently have drawbacks and negative side effects. This paper also summarizes the pharmacological mechanism and application of Chinese herbal compounds (Berberine, Sanguinarine, Astragalus polysaccharide, Curcumin, and Cannabinoids) and formulae (Wumei Wan, Gegen-Qinlian decoction, Banxia xiexin decoction) against intestinal inflammation. We show that the herbal compounds and formulae may influence the interactions among cell signaling pathways, immune function, and gut microbiota in humans and animals, exerting their immunomodulatory capacity and anti-inflammatory and antimicrobial effects. This demonstrates their strong potential to improve gut inflammation. We aim to promote herbal medicine and apply it to multispecies animals to achieve better health.

Neuropathic pain; what we know and what we should do about it

Neuropathic pain can result from injury to, or disease of the nervous system. It is notoriously difficult to treat. Peripheral nerve injury promotes Schwann cell activation and invasion of immunocompetent cells into the site of injury, spinal cord and higher sensory structures such as thalamus and cingulate and sensory cortices. Various cytokines, chemokines, growth factors, monoamines and neuropeptides effect two-way signalling between neurons, glia and immune cells. This promotes sustained hyperexcitability and spontaneous activity in primary afferents that is crucial for onset and persistence of pain as well as misprocessing of sensory information in the spinal cord and supraspinal structures. Much of the current understanding of pain aetiology and identification of drug targets derives from studies of the consequences of peripheral nerve injury in rodent models. Although a vast amount of information has been forthcoming, the translation of this information into the clinical arena has been minimal. Few, if any, major therapeutic approaches have appeared since the mid 1990's. This may reflect failure to recognise differences in pain processing in males vs. females, differences in cellular responses to different types of injury and differences in pain processing in humans vs. animals. Basic science and clinical approaches which seek to bridge this knowledge gap include better assessment of pain in animal models, use of pain models which better emulate human disease, and stratification of human pain phenotypes according to quantitative assessment of signs and symptoms of disease. This can lead to more personalized and effective treatments for individual patients. Significance statement: There is an urgent need to find new treatments for neuropathic pain. Although classical animal models have revealed essential features of pain aetiology such as peripheral and central sensitization and some of the molecular and cellular mechanisms involved, they do not adequately model the multiplicity of disease states or injuries that may bring forth neuropathic pain in the clinic. This review seeks to integrate information from the multiplicity of disciplines that seek to understand neuropathic pain; including immunology, cell biology, electrophysiology and biophysics, anatomy, cell biology, neurology, molecular biology, pharmacology and behavioral science. Beyond this, it underlines ongoing refinements in basic science and clinical practice that will engender improved approaches to pain management.

Preemptive transcranial direct current stimulation induces analgesia, prevents chronic inflammation and fibrosis, and promotes tissue repair in a rat model of postoperative pain

This study evaluated the effects of previous exposure to Transcranial Direct Current Stimulation (tDCS) on nociceptive, neuroinflammatory, and neurochemical parameters, in rats subjected to an incisional pain model. Forty adult male Wistar rats (60 days old; weighing ∼ 250 g) were divided into five groups: 1. control (C); 2. drugs (D); 3. surgery (S); 4. surgery + sham-tDCS (SsT) and 5. surgery + tDCS (ST). Bimodal tDCS (0.5 mA) was applied for 20 min/day/8 days before the incisional model. Mechanical allodynia (von Frey) was evaluated at different time points after surgery. Cytokines and BDNF levels were evaluated in the cerebral cortex, hippocampus, brainstem, and spinal cord. Histology and activity of myeloperoxidase (MPO) and N-acetyl-β-D-glucosaminidase (NAGase) were evaluated in the surgical lesion sites in the right hind paw. The results demonstrate that the surgery procedure increased BDNF and IL-6 levels in the spinal cord levels in the hippocampus, and decreased IL-1β and IL-6 levels in the cerebral cortex, IL-6 levels in the hippocampus, and IL-10 levels in the brainstem and hippocampus. In addition, preemptive tDCS was effective in controlling postoperative pain, increasing BDNF, IL-6, and IL-10 levels in the spinal cord and brainstem, increasing IL-1β in the spinal cord, and decreasing IL-6 levels in the cerebral cortex and hippocampus, IL-1β and IL-10 levels in the hippocampus. Preemptive tDCS also contributes to tissue repair, preventing chronic inflammation, and consequent fibrosis. Thus, these findings imply that preemptive methods for postoperative pain management should be considered an interesting pain management strategy, and may contribute to the development of clinical applications for tDCS in surgical situations.

NOD-like receptors mediate homeostatic intestinal epithelial barrier function: promising therapeutic targets for inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic gastrointestinal inflammatory disease that involves host genetics, the microbiome, and inflammatory responses. The current consensus is that the disruption of the intestinal mucosal barrier is the core pathogenesis of IBD, including intestinal microbial factors, abnormal immune responses, and impaired intestinal mucosal barrier. Cumulative data show that nucleotide-binding and oligomerization domain (NOD)-like receptors (NLRs) are dominant mediators in maintaining the homeostasis of the intestinal mucosal barrier, which play critical roles in sensing the commensal microbiota, maintaining homeostasis, and regulating intestinal inflammation. Blocking NLRs inflammasome activation by botanicals may be a promising way to prevent IBD progression. In this review, we systematically introduce the multiple roles of NLRs in regulating intestinal mucosal barrier homeostasis and focus on summarizing the activities and potential mechanisms of natural products against IBD. Aiming to propose new directions on the pathogenesis and precise treatment of IBD.

Neat1 lncRNA organizes the inflammatory gene expressions in the dorsal root ganglion in neuropathic pain caused by nerve injury

Primary sensory neurons regulate inflammatory processes in innervated regions through neuro-immune communication. However, how their immune-modulating functions are regulated in concert remains largely unknown. Here, we show that Neat1 long non-coding RNA (lncRNA) organizes the proinflammatory gene expressions in the dorsal root ganglion (DRG) in chronic intractable neuropathic pain in rats. Neat1 was abundantly expressed in the DRG and was upregulated after peripheral nerve injury. Neat1 overexpression in primary sensory neurons caused mechanical and thermal hypersensitivity, whereas its knockdown alleviated neuropathic pain. Bioinformatics analysis of comprehensive transcriptome changes indicated the inflammatory response was the most relevant function of genes upregulated through Neat1. Consistent with this, upregulation of proinflammatory genes in the DRG following nerve injury was suppressed by Neat1 knockdown. Expression changes of these proinflammatory genes were regulated through Neat1-mRNA interaction-dependent and -independent mechanisms. Notably, Neat1 increased proinflammatory genes by stabilizing its interacting mRNAs in neuropathic pain. Finally, Neat1 in primary sensory neurons contributed to spinal inflammatory processes that mediated peripheral neuropathic pain. These findings demonstrate that Neat1 lncRNA is a key regulator of neuro-immune communication in neuropathic pain.

The Association Between Immune-Related Conditions Across the Life-Course and Provoked Vulvodynia

Vulvodynia, impacts up to 8% of women by age 40, and is hypothesized to manifest through an altered immune-inflammatory response. To test this hypothesis, we identified all women born in Sweden between 1973 and 1996 diagnosed with localized provoked vulvodynia (N76.3) and/or vaginismus (N94.2 or F52.5) between 2001 and 2018. We matched each case to two women from the same birth year with no vulvar pain ICD codes. As a proxy for immune dysfunction, we used Swedish Registry data to capture 1) immunodeficiencies, 2) single organ and multiorgan autoimmune conditions, 3) allergy and atopies, and 4) malignancies involving immune cells across the life course. Women with vulvodynia, vaginismus or both were more likely to experience immune deficiencies (OR 1.8, 95% CI, 1.2-2.8), single organ (OR 1.4, 95% CI, 1.2-1.6) and/or multi-organ (OR 1.6, 95% CI, 1.3-1.9) immune disorders, and allergy/atopy conditions (OR 1.7, 95% CI, 1.6-1.8) compared to controls. We observed greater risk with increasing numbers of unique immune related conditions (1 code: OR = 1.6, 95% CI, 1.5-1.7; 2 codes: OR = 2.4, 95% CI, 2.1-2.9; 3 or more codes: OR = 2.9, 1.6-5.4). These findings suggest that women with vulvodynia may have a more compromised immune system either at birth or at points across the life course than women with no vulvar pain history. PERSPECTIVE: Women with vulvodynia are substantially more likely to experience a spectrum of immune related conditions across the life course. These findings lend support to the hypothesis that chronic inflammation initiates the hyperinnervation that causes the debilitating pain in women with vulvodynia.

[Role of the sympathetic nervous system in chronic inflammation]

In this review article the current model of the interaction between the sympathetic nervous system (SNS) and the immune system in the context of chronic inflammation is presented. Mechanisms in the interaction between the SNS and the immune system are shown, which are similar for all disease entities: 1) the biphasic effect of the sympathetic system on the inflammatory response with a proinflammatory, stimulating effect before and during the activation of the immune system (early) and a more inhibitory effect in late phases of immune activation (chronic). 2) The interruption of communication between immune cells and the brain by withdrawal of sympathetic nerve fibers from areas of inflammation, such as the spleen, lymph nodes or peripheral foci of inflammation. 3) The local replacement of catecholamines by neurotransmitter-producing cells to fine-tune the local immune response independently of the brain. 4) Increased activity of the SNS due to an imbalance of the autonomic nervous system at the systemic level, which provides an explanation for known disease sequelae and comorbidities due to the long duration of chronic inflammatory reactions, such as increased cardiovascular risk with hypertension, diabetes mellitus and catabolic metabolism. The understanding of neuroimmune interactions can lead to new therapeutic approaches, e.g., a stimulation of beta-adrenergic and even more an inhibition of alpha-adrenergic receptors or a restoration of the autonomic balance in the context of arthritis ) can make an anti-inflammatory contribution (more influence of the vagus nerve); however, in order to translate the theoretical findings into clinical action that is beneficial for the patient, controlled interventional studies are required.

Proof-of-Concept Human Organ-on-Chip Study: First Step of Platform to Assess Neuro-Immunological Communication Involved in Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBD) are complex chronic inflammatory disorders of the gastrointestinal (GI) tract. Recent evidence suggests that the gut-brain axis may be pivotal in gastrointestinal and neurological diseases, especially IBD. Here, we present the first proof of concept for a microfluidic technology to model bilateral neuro-immunological communication. We designed a device composed of three compartments with an asymmetric channel that allows the isolation of soma and neurites thanks to microchannels and creates an in vitro synaptic compartment. Human-induced pluripotent stem cell-derived cortical glutamatergic neurons were maintained in soma compartments for up to 21 days. We performed a localized addition of dendritic cells (MoDCs) to either the soma or synaptic compartment. The microfluidic device was coupled with microelectrode arrays (MEAs) to assess the impact on the electrophysiological activity of neurons while adding dendritic cells. Our data highlight that an electrophysiologic signal is transmitted between two compartments of glutamatergic neurons linked by synapses in a bottom-up way when soma is exposed to primed dendritic cells. In conclusion, our study authenticates communication between dendritic cells and neurons in inflammatory conditions such as IBD. This platform opens the way to complexification with gut components to reach a device for pharmacological compound screening by blocking the gut-brain axis at a mucosal level and may help patients.

Electroacupuncture at Neiguan (PC6) attenuates cardiac dysfunction caused by cecal ligation and puncture via the vagus nerve

PURPOSE

Previous studies proved the benefits of electroacupuncture (EA) on heart in ischemia reperfusion injury and chronic heart failure. However, the role of EA on sepsis-induced cardiac dysfunction has rarely been elucidated before. In this study, we aimed to investigate the effects of EA on cardiac dysfunction in a rat model of sepsis and to speculate the underlying mechanisms.

METHODS

Sepsis was induced by cecum ligation and puncture in anesthetized rats. EA at the acupoint "Neiguan (PC6)" was applied 0.5 h after the induction of sepsis for 20 min. Heart rate variability was obtained immediately after EA to evaluate autonomic balance. Echocardiography was performed at 6 h and 24 h after sepsis induction in vivo. Measurements of hemodynamics, blood gases, cytokines and biochemistry were collected at 24 h. Cardiac tissue underwent immunofluorescence staining to determine the expression of α7 nicotinic acetylcholine receptor (α7nAChR) on macrophages.

RESULTS

EA increased vagus nerve activity, prevented the development of hyperlactatemia, attenuated the decline of left ventricle ejection fraction, suppressed systemic and cardiac inflammation and alleviated the histopathological manifestations of heart in sepsis rats. Furthermore, the cardiac tissue from EA treated rats showed increased expressions of α7nAChR on macrophages. The cardio-protective and anti-inflammatory effects of EA were partly or completely prevented in rats with vagotomy.

CONCLUSION

EA at PC6 attenuates left ventricle dysfunction and decreases inflammation in sepsis-induced cardiac dysfunction. The cardio-protective effects of EA are mediated through vagus nerve mediated cholinergic pathway.

The tumor-nerve circuit in breast cancer

It is well established that innervation is one of the updated hallmarks of cancer and that psychological stress promotes the initiation and progression of cancer. The breast tumor environment includes not only fibroblasts, adipocytes, endothelial cells, and lymphocytes but also neurons, which is increasingly discovered important in breast cancer progression. Peripheral nerves, especially sympathetic, parasympathetic, and sensory nerves, have been reported to play important but different roles in breast cancer. However, their roles in the breast cancer progression and treatment are still controversial. In addition, the brain is one of the favorite sites of breast cancer metastasis. In this review, we first summarize the innervation of breast cancer and its mechanism in regulating cancer growth and metastasis. Next, we summarize the neural-related molecular markers in breast cancer diagnosis and treatment. In addition, we review drugs and emerging technologies used to block the interactions between nerves and breast cancer. Finally, we discuss future research directions in this field. In conclusion, the further research in breast cancer and its interactions with innervated neurons or neurotransmitters is promising in the clinical management of breast cancer.

Neurodegenerative and Neurodevelopmental Diseases and the Gut-Brain Axis: The Potential of Therapeutic Targeting of the Microbiome

The human gut microbiome contains the largest number of bacteria in the body and has the potential to greatly influence metabolism, not only locally but also systemically. There is an established link between a healthy, balanced, and diverse microbiome and overall health. When the gut microbiome becomes unbalanced (dysbiosis) through dietary changes, medication use, lifestyle choices, environmental factors, and ageing, this has a profound effect on our health and is linked to many diseases, including lifestyle diseases, metabolic diseases, inflammatory diseases, and neurological diseases. While this link in humans is largely an association of dysbiosis with disease, in animal models, a causative link can be demonstrated. The link between the gut and the brain is particularly important in maintaining brain health, with a strong association between dysbiosis in the gut and neurodegenerative and neurodevelopmental diseases. This link suggests not only that the gut microbiota composition can be used to make an early diagnosis of neurodegenerative and neurodevelopmental diseases but also that modifying the gut microbiome to influence the microbiome-gut-brain axis might present a therapeutic target for diseases that have proved intractable, with the aim of altering the trajectory of neurodegenerative and neurodevelopmental diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, autism spectrum disorder, and attention-deficit hyperactivity disorder, among others. There is also a microbiome-gut-brain link to other potentially reversible neurological diseases, such as migraine, post-operative cognitive dysfunction, and long COVID, which might be considered models of therapy for neurodegenerative disease. The role of traditional methods in altering the microbiome, as well as newer, more novel treatments such as faecal microbiome transplants and photobiomodulation, are discussed.