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Brain, Behavior, and Immunity May 2024Gut microbiota communicates bidirectionally with the brain through the nervous, immune, and endocrine systems of the gut. In our preliminary study, the fecal microbiota...
Gut microbiota communicates bidirectionally with the brain through the nervous, immune, and endocrine systems of the gut. In our preliminary study, the fecal microbiota of volunteers with mild cognitive impairment (Fmci) exhibited a higher abundance of Escherichia fergusonii (NK2001), Veillonella infantium (NK2002), and Enterococcus faecium (NK2003) populations compared with those of healthy volunteers. Therefore, we examined the effects of Fmci, NK2001 (gram-negative), NK2002 (gram-negative-like), and NK2003 (gram-positive) on cognitive impairment-like behavior, neuroinflammation, and colitis in mice with or without antibiotics. Fmci transplantation increased cognitive impairment-like behavior, hippocampal tumor necrosis factor (TNF)-α expression, and the size of toll-like receptor (TLR)4Iba1, TLR2Iba1, and NF-κBIba1 cell populations independent of antibiotic treatment. Oral gavage of NK2001, NK2002, or NK2003, which induced TNF-α expression in Caco-2 cells, significantly increased cognitive impairment-like behavior and hippocampal TNF-α expression and Iba1-positive cell populations and decreased brain-derived neurotrophic factor (BDNF) expression in mice. Celiac vagotomy significantly decreased NK2001- or NK2002-induced cognitive impairment-like behavior and hippocampal Iba1 cell population and TNF-α expression and increased NK2001- or NK2002-suppressed hippocampal BDNF expression. However, NK2003-induced cognitive impairment-like behavior and hippocampal Iba1 cell population and TNF-α expression were partially, but not significantly, attenuated by celiac vagotomy. Furthermore, celiac vagotomy did not affect NK2001-, NK2002-, or NK2003-induced lipopolysaccharide (LPS) levels in the blood and feces and TNF-α expression and NF-κB-positive cell population in the colon. In conclusion, LPS-producing NK2001 and NK2002 and LPS-nonproducing NK2003 may induce NF-κB-mediated neuroinflammation through the translocation of byproducts such as LPS and peptidoglycan into the brain through gut-blood/vagus nerve-brain and gut-blood-brain pathways, respectively, resulting in cognitive impairment.
Topics: Humans; Mice; Animals; Lipopolysaccharides; NF-kappa B; Brain-Derived Neurotrophic Factor; Tumor Necrosis Factor-alpha; Neuroinflammatory Diseases; Caco-2 Cells; Cognitive Dysfunction; Vagus Nerve; Mice, Inbred C57BL; Escherichia; Veillonella
PubMed: 38428648
DOI: 10.1016/j.bbi.2024.02.031 -
MedRxiv : the Preprint Server For... Apr 2024Emerging preclinical evidence suggests that vagal signals contribute to the development of schizophrenia-related abnormalities in brain and behavior. Whether vagal...
BACKGROUND AND OBJECTIVES
Emerging preclinical evidence suggests that vagal signals contribute to the development of schizophrenia-related abnormalities in brain and behavior. Whether vagal communication in general, and its impairment in particular, is a risk factor for schizophrenia in humans remains, however, unclear. Vagotomy, the surgical lesion of the vagus nerve, was routinely performed as a treatment for peptic ulcer before modern treatment options were available. Hence, the primary aim of this study was to investigate whether vagotomy modulates the subsequent risk of developing schizophrenia. Moreover, given the existence of diverse vagotomy techniques (i.e., "truncal" or "selective"), our secondary goal was to test whether the extent of denervation modulates the risk of schizophrenia.
METHODS
Using a nationwide retrospective matched cohort design, we identified 8,315 vagotomized individuals from the Swedish National Patient Register during the period 1970-2020 and 40,855 non-vagotomized individuals matching for age, sex and type of peptic ulcer. The risk of being diagnosed with schizophrenia and associated psychoses (ICD10 codes F20-29) was analyzed using Cox proportional hazards regression models, including death as competing risk.
RESULTS
When considering all types of vagotomy together, vagotomy was not significantly associated with schizophrenia (HR: 0.91 [0.72; 1.16]). However, truncal vagotomy (which denervates all subdiaphragmatic organs) significantly increased the risk of developing schizophrenia by 69% (HR: 1.69 [1.08; 2.64]), whereas selective vagotomy (which only denervates the stomach) showed no significant association (HR: 0.80 [0.61; 1.04]).
DISCUSSION
Our results provide epidemiological support for the hypothesis that impairments in vagal functions could increase the risk of schizophrenia. Notably, the finding that truncal but not selective vagotomy is associated with an increased risk of schizophrenia raises the possibility that the activity of subdiaphragmatic non-gastric vagal branches may be of particular relevance for the development of schizophrenia.
PubMed: 38352405
DOI: 10.1101/2024.01.30.24301418 -
Neurobiology of Disease Mar 2024Depression frequently occurs in patients with liver cirrhosis, yet the reasons for this correlation are not fully understood. Dysbiosis of gut microbiota has been...
Depression frequently occurs in patients with liver cirrhosis, yet the reasons for this correlation are not fully understood. Dysbiosis of gut microbiota has been implicated in depression through the gut-brain axis via the vagus nerve. This study explored the potential role of the gut-liver-brain axis via the vagus nerve in depression-like phenotypes in mice with liver cirrhosis. These mice underwent common bile duct ligation (CBDL), a method used to stimulate liver cirrhosis. To assess depression-like behaviors, behavioral tests were conducted 10 days following either sham or CBDL surgeries. The mice with CBDL displayed symptoms such as splenomegaly, elevated plasma levels of interleukin-6 and tumor necrosis factor-α, depression-like behaviors, decreased levels of synaptic proteins in the prefrontal cortex (PFC), disrupted gut microbiota balance, and changes in blood metabolites (or lipids). Additionally, there were positive or negative correlations between the relative abundance of microbiome and behavioral data or blood metabolites (or lipids). Significantly, these changes were reversed in CBDL mice by performing a subdiaphragmatic vagotomy. Intriguingly, depression-like phenotypes in mice with CBDL were improved after a single injection of arketamine, a new antidepressant. These results suggest that CBDL-induced depression-like phenotypes in mice are mediated through the gut-liver-brain axis via the subdiaphragmatic vagus nerve, and that arketamine might offer a new treatment approach for depression in liver cirrhosis patients.
Topics: Mice; Humans; Animals; Brain-Gut Axis; Depression; Common Bile Duct; Liver Cirrhosis; Vagus Nerve; Ligation; Brain; Lipids
PubMed: 38331354
DOI: 10.1016/j.nbd.2024.106433 -
BioRxiv : the Preprint Server For... Jan 2024Liver cancer ranks amongst the deadliest cancers. Nerves have emerged as an understudied regulator of tumor progression. The parasympathetic vagus nerve influences...
Liver cancer ranks amongst the deadliest cancers. Nerves have emerged as an understudied regulator of tumor progression. The parasympathetic vagus nerve influences systemic immunity via acetylcholine (ACh). Whether cholinergic neuroimmune interactions influence hepatocellular carcinoma (HCC) remains uncertain. Liver denervation via hepatic vagotomy (HV) significantly reduced liver tumor burden, while pharmacological enhancement of parasympathetic tone promoted tumor growth. Cholinergic disruption in Rag1KO mice revealed that cholinergic regulation requires adaptive immunity. Further scRNA-seq and in vitro studies indicated that vagal ACh dampens CD8+ T cell activity via muscarinic ACh receptor (AChR) CHRM3. Depletion of CD8+ T cells abrogated HV outcomes and selective deletion of on CD8 T cells inhibited liver tumor growth. Beyond tumor-specific outcomes, vagotomy improved cancer-associated fatigue and anxiety-like behavior. As microbiota transplantation from HCC donors was sufficient to impair behavior, we investigated putative microbiota-neuroimmune crosstalk. Tumor, rather than vagotomy, robustly altered fecal bacterial composition, increasing Desulfovibrionales and Clostridial taxa. Strikingly, in tumor-free mice, vagotomy permitted HCC-associated microbiota to activate hepatic CD8+ T cells. These findings reveal that gut bacteria influence behavior and liver anti-tumor immunity via a dynamic and pharmaceutically targetable, vagus-liver axis.
PubMed: 38328040
DOI: 10.1101/2024.01.23.576951 -
Biology Jan 2024Glucosensing elements are widely distributed throughout the body and relay information about circulating glucose levels to the brain via the vagus nerve. However, while...
BACKGROUND
Glucosensing elements are widely distributed throughout the body and relay information about circulating glucose levels to the brain via the vagus nerve. However, while anatomical wiring has been established, little is known about the physiological role of the vagus nerve in glucosensing. The contribution of the vagus nerve to inflammation in the fetus is poorly understood. Increased glucose levels and inflammation act synergistically when causing organ injury, but their interplay remains incompletely understood. We hypothesized that vagotomy (Vx) will trigger a rise in systemic glucose levels and this will be enhanced during systemic and organ-specific inflammation. Efferent vagus nerve stimulation (VNS) should reverse this phenotype.
METHODS
Near-term fetal sheep (n = 57) were surgically prepared using vascular catheters and ECG electrodes as the control and treatment groups (lipopolysaccharide (LPS), Vx + LPS, Vx + LPS + selective efferent VNS). The experiment was started 72 h postoperatively to allow for post-surgical recovery. Inflammation was induced with LPS bolus intravenously (LPS group, 400 ng/fetus/day for 2 days; n = 23). For the Vx + LPS group (n = 11), a bilateral cervical vagotomy was performed during surgery; of these n = 5 received double the LPS dose, LPS800. The Vx + LPS + efferent VNS group (n = 8) received cervical VNS probes bilaterally distal from Vx in eight animals. Efferent VNS was administered for 20 min on days 1 and 2 +/10 min around the LPS bolus. Fetal arterial blood samples were drawn on each postoperative day of recovery (-72 h, -48 h, and -24 h) as well as at the baseline and seven selected time points (3-54 h) to profile inflammation (ELISA IL-6, pg/mL), insulin (ELISA), blood gas, and metabolism (glucose). At 54 h post-LPS, a necropsy was performed, and the terminal ileum macrophages' CD11c (M1 phenotype) immunofluorescence was quantified to detect inflammation. The results are reported for < 0.05 and for Spearman R2 > 0.1. The results are presented as the median (IQR).
RESULTS
Across the treatment groups, blood gas and cardiovascular changes indicated mild septicemia. At 3 h in the LPS group, IL-6 peaked. That peak was decreased in the Vx + LPS400 group and doubled in the Vx + LPS800 group. The efferent VNS sped up the reduction in the inflammatory response profile over 54 h. The M1 macrophage activity was increased in the LPS and Vx + LPS800 groups only. The glucose and insulin concentrations in the Vx + LPS group were, respectively, 1.3-fold (throughout the experiment) and 2.3-fold higher vs. control (at 3 h). The efferent VNS normalized the glucose concentrations.
CONCLUSIONS
The complete withdrawal of vagal innervation resulted in a 72-h delayed onset of a sustained increase in glucose for at least 54 h and intermittent hyperinsulinemia. Under the conditions of moderate fetal inflammation, this was related to higher levels of gut inflammation. The efferent VNS reduced the systemic inflammatory response as well as restored both the concentrations of glucose and the degree of terminal ileum inflammation, but not the insulin concentrations. Supporting our hypothesis, these findings revealed a novel regulatory, hormetic, role of the vagus nerve in the immunometabolic response to endotoxin in near-term fetuses.
PubMed: 38248469
DOI: 10.3390/biology13010038 -
World Journal of Gastrointestinal... Dec 2023Rapid regeneration of the residual liver is one of the key determinants of successful partial hepatectomy (PHx). At present, there is a lack of recognized safe,...
BACKGROUND
Rapid regeneration of the residual liver is one of the key determinants of successful partial hepatectomy (PHx). At present, there is a lack of recognized safe, effective, and stable drugs to promote liver regeneration. It has been reported that vagus nerve signaling is beneficial to liver regeneration, but the potential mechanism at play here is not fully understood.
AIM
To explore the effect and mechanism of hepatic vagus nerve in liver regeneration after PHx.
METHODS
A PHx plus hepatic vagotomy (Hv) mouse model was established. The effect of Hv on liver regeneration after PHx was determined by comparing the liver regeneration levels of the PHx-Hv group and the PHx-sham group mice. In order to further investigate the role of interleukin (IL)-22 in liver regeneration inhibition mediated by Hv, the levels of IL-22 in the PHx-Hv group and the PHx-sham group was measured. The degree of liver injury in the PHx-Hv group and the PHx-sham group mice was detected to determine the role of the hepatic vagus nerve in liver injury after PHx.
RESULTS
Compared to control-group mice, Hv mice showed severe liver injury and weakened liver regeneration after PHx. Further research found that Hv downregulates the production of IL-22 induced by PHx and blocks activation of the signal transducer and activator of transcription 3 (STAT3) pathway then reduces the expression of various mitogenic and anti-apoptotic proteins after PHx. Exogenous IL-22 reverses the inhibition of liver regeneration induced by Hv and alleviates liver injury, while treatment with IL-22 binding protein (an inhibitor of IL-22 signaling) reduce the concentration of IL-22 induced by PHx, inhibits the activation of the STAT3 signaling pathway in the liver after PHx, thereby hindering liver regeneration and aggravating liver injury in PHx-sham mice.
CONCLUSION
Hv attenuates liver regeneration after hepatectomy, and the mechanism may be related to the fact that Hv downregulates the production of IL-22, then blocks activation of the STAT3 pathway.
PubMed: 38222006
DOI: 10.4240/wjgs.v15.i12.2866 -
ACG Case Reports Journal Jan 2024is a known cause of peptic ulcers, but it has not been reported to cause strictures in children. We present the case of a previously healthy 12-year-old boy with sudden...
is a known cause of peptic ulcers, but it has not been reported to cause strictures in children. We present the case of a previously healthy 12-year-old boy with sudden onset of abdominal pain and vomiting, positive stool antigen testing, and esophagogastroduodenoscopy revealing a gastroduodenal stricture causing gastric outlet obstruction. Because of medically refractory disease, he ultimately required laparoscopic truncal vagotomy with open pyloroplasty. This is an unusually severe presentation and may warrant being on the differential of pediatric gastrointestinal strictures as well as further discussion on other long-term implications.
PubMed: 38162007
DOI: 10.14309/crj.0000000000001227 -
Pharmaceuticals (Basel, Switzerland) Dec 2023Purine nucleosides (adenosine) and nucleotides such as adenosine mono/di/triphosphate (AMP/ADP/ATP) may produce complex cardiovascular responses. For example,...
Purine nucleosides (adenosine) and nucleotides such as adenosine mono/di/triphosphate (AMP/ADP/ATP) may produce complex cardiovascular responses. For example, adenosine-5'-(β-thio)-diphosphate (ADPβS; a stable synthetic analogue of ADP) can induce vasodilatation/vasodepressor responses by endothelium-dependent and independent mechanisms involving purinergic P2Y receptors; however, the specific subtypes participating in these responses remain unknown. Therefore, this study investigated the receptor subtypes mediating the blood pressure changes induced by intravenous bolus of ADPβS in male Wistar rats in the absence and presence of central mechanisms with the antagonists MRS2500 (P2Y), PSB0739 (P2Y), and MRS2211 (P2Y). For this purpose, 120 rats were divided into 60 anaesthetised rats and 60 pithed rats, and further subdivided into four groups ( = 30 each), namely: (a) anaesthetised rats, (b) anaesthetised rats with bilateral vagotomy, (c) pithed rats, and (d) pithed rats continuously infused (intravenously) with methoxamine (an α-adrenergic agonist that restores systemic vascular tone). We observed, in all four groups, that the immediate decreases in diastolic blood pressure produced by ADPβS were exclusively mediated by peripheral activation of P2Y receptors. Nevertheless, the subsequent increases in systolic blood pressure elicited by ADPβS in pithed rats infused with methoxamine probably involved peripheral activation of P2Y, P2Y, and P2Y receptors.
PubMed: 38139810
DOI: 10.3390/ph16121683 -
International Journal of Surgery... Mar 2024Chronic cough is common after lobectomy. Vagus nerves are part of the cough reflex. Accordingly, transection of the pulmonary branches of vagus nerve may prevent chronic... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Chronic cough is common after lobectomy. Vagus nerves are part of the cough reflex. Accordingly, transection of the pulmonary branches of vagus nerve may prevent chronic cough. And there are no clear recommendations on the management of the pulmonary branches of vagus in any thoracic surgery guidelines.
METHODS
This is a single-center, randomized controlled trial. Adult patients undergoing elective video-assisted thoracoscopic lobectomy and lymphadenectomy were randomized at a 1:1 ratio to undergo a sham procedure (control group) or transection of the pulmonary branches of the vagus nerve that innervate the bronchial stump plus the caudal-most large pulmonary branch of the vagus nerve. The primary outcome was the rate of chronic cough, as assessed at 3 months after surgery in the intent-to-treat population.
RESULTS
Between 1 February 2020 and 1 August 2020, 116 patients (59.6±10.1 years of age; 45 men) were randomized (58 in each group). All patients received designated intervention. The rate of chronic cough at 3 months was 19.0% (11/58) in the vagotomy group versus 41.4% (24/58) in the control group (OR=0.332, 95% CI: 0.143-0.767; P =0.009). In the 108 patients with 2-year assessment, the rate of persistent cough was 12.7% (7/55) in the control and 1.9% (1/53) in the vagotomy group ( P =0.032). The two groups did not differ in postoperative complications and key measures of pulmonary function, for example, maximal voluntary ventilation, diffusing capacity of the lungs for carbon monoxide, and forced expiratory volume.
CONCLUSION
Transecting the pulmonary branches of vagus nerve that innervate the bronchial stump plus the caudal-most large pulmonary branch decreased the rate of chronic cough without affecting pulmonary function in patients undergoing video-assisted lobectomy and lymphadenectomy.
Topics: Adult; Humans; Male; Chronic Cough; Lung; Lung Neoplasms; Pneumonectomy; Thoracic Surgery, Video-Assisted; Vagus Nerve; Vagus Nerve Injuries; Female; Middle Aged; Aged
PubMed: 38116674
DOI: 10.1097/JS9.0000000000001017 -
BioRxiv : the Preprint Server For... Dec 2023Circadian desynchrony induced by shiftwork or jetlag is detrimental to metabolic health, but how synchronous/desynchronous signals are transmitted among tissues is...
UNLABELLED
Circadian desynchrony induced by shiftwork or jetlag is detrimental to metabolic health, but how synchronous/desynchronous signals are transmitted among tissues is unknown. Here we report that liver molecular clock dysfunction is signaled to the brain via the hepatic vagal afferent nerve (HVAN), leading to altered food intake patterns that are corrected by ablation of the HVAN. Hepatic branch vagotomy also prevents food intake disruptions induced by high-fat diet feeding and reduces body weight gain. Our findings reveal a previously unrecognized homeostatic feedback signal that relies on synchrony between the liver and the brain to control circadian food intake patterns. This identifies the hepatic vagus nerve as a therapeutic target for obesity in the setting of chrono-disruption.
ONE SENTENCE SUMMARY
The hepatic vagal afferent nerve signals internal circadian desynchrony between the brain and liver to induce maladaptive food intake patterns.
PubMed: 38077098
DOI: 10.1101/2023.11.30.568080