Role Of Cholinergic Anti-inflammatory Pathway Research Articles

Effect of electroacupuncture on myocardial fibrosis in spontaneously hypertensive rats based on cholinergic anti-inflammatory pathway

To observe the effect of electroacupuncture (EA) at "Neiguan" (PC 6) on myocardial fibrosis in spontaneously hypertensive rats (SHR), and explore preliminarily the mediating role of cholinergic anti-inflammatory pathway (CAP) and its downstream nuclear factor κB (NF-κB) signaling pathway. Six 12-week-old WKY male rats were employed as the normal group. Eighteen 12-week-old SHR were randomly divided into 3 groups, i.e. a model group, an EA group and a blocking group (EA after blocking α7 nicotinic acetylcholine receptor [α7nAchR]), with 6 rats in each one. In the EA group, EA was delivered at "Neiguan"(PC 6) and the site 0.5 cm from its left side, with disperse-dense wave, 2 Hz/15 Hz in frequency and 1 mA in current intensity. One intervention took 30 min and was given once every 2 days, lasting 8 weeks. In the blocking group, prior to each EA, the α7nAchR specific blocker, α-bungartoxin was injected intravenously in the tails of the rats. After EA intervention, the systolic blood pressure (SBP), the diastolic blood pressure (DBP) and the mean arterial pressure (MAP) were measured with non-invasive blood pressure monitor. Using echocardiogram, the left ventricular (LV) anterior wall end-diastolic thickness (LVAWd) , LV posterior wall end-diastolic thickness (LVPWd) and the LV end-diastolic internal diameter (LVIDd) were measured. The level of hydroxyproline (Hyp) in the myocardial tissue was determined by using alkaline hydrolysis, and that of acetylcholine (Ach) was detected by ELISA. With the real-time PCR adopted, the mRNA expression of NF-κB p65, tumor necrosis factor α (TNF-α), interleukin (IL)-1β and IL-6 were determined. Compared with the normal group, SBP, DBP, MAP, LVAWd and LVPWd were increased (P<0.01), and LVIDd was decreased (P<0.01) in the rats of the model group. SBP, DBP, MAP and LVAWd were dropped (P<0.01, P<0.05), and LVIDd rose (P<0.01) in the EA group when compared with those in the model group. The differences in the above indexes were not statistically significant between the blocking group and the model group (P>0.05). Compared with the normal group, Hyp level and the mRNA expression of NF-κB p65, TNF-α, IL-1β and IL-6 in the myocardial tissue increased (P<0.01, P<0.05) and Ach level decreased (P<0.01) in the model group. Hyp level, the mRNA expression of NF-κB p65, TNF-α, IL-1β and IL-6 in the myocardial tissue were reduced (P<0.05, P<0.01) and Ach level rose (P<0.01) in the EA group when compared with those in the model group. These indexes were not different statistically between the blocking group and the model group (P>0.05). CAP may be involved in ameliorating the pathological damage of myocardial fibrosis during EA at "Neiguan"(PC 6). The underlying effect mechanism is associated with up-regulating the neurotransmitter, Ach and down-regulating mRNA expression of NF-κB p65 and pro-inflammatory factors such as TNF-α, IL-1β and IL-6 in myocardial tissue.

Role of cholinergic anti-inflammatory pathway in the regulation of vascular endothelial permeability and inflammation in type 2 diabetes

Abstract Despite tremendous advancement in glycemic control, anti-diabetic medications have failed to revert vascular impairment once triggered by the metabolic disorder. The cholinergic anti-inflammatory pathway (CAP) is a neurophysiological mechanism that regulates the immune system. Studies show that the CAP inhibits inflammation by suppressing cytokine synthesis via release of acetylcholine in organs of the reticuloendothelial system, including the heart, lungs and gastrointestinal tract. Upon release, acetylcholine interacts with α7 nicotinic acetylcholine receptors (α7nAChR), down-regulate pro-inflammatory cytokine synthesis and prevent tissue damage and inflammation. Although a CAP modulated the response to severe inflammation during sepsis, the role of this pathway in the regulation of type-2 diabetes (T2D)-induced increase in endothelial permeability is completely unknown. Our data showed that human coronary artery endothelial cells (HCAECs) from T2D displayed increased endothelial permeability and enhanced pro-inflammatory signaling in response to pro-coagulant thrombin and endotoxin lipopolysaccharide (LPS), respectively. We also found increased expression and activity of acetylcholinesterase enzyme, and no change in expression of α7nAChR in T2D endothelial cells (ECs) compared to ECs from normal subjects. Our research findings showed that the T2D increased the expression and activity of AChE enzyme in HCAECs, and thereby decreasing the availability of ACh at α7nAChR. In summary, our work offered novel insights and therapeutic targets that we think will lead to the development of more effective treatments with improved outcomes. Grant from CTRE Chicago State University, Chicago, IL

Role of cholinergic anti-inflammatory pathway in Ghrelin regulation of peptide transporter 1 expression in small intestinal epithelium of septic rats

To investigate the role of cholinergic anti-inflammatory pathway in the regulation of peptide transporter 1 (PepT1) expression in small intestinal epithelium of septic rats by Ghrelin. One hundred adult male Sprague-Dawley (SD) rats were randomly divided into sham operation group, sepsis group, sepsis+vagotomy group, sepsis+Ghrelin group, and sepsis+vagotomy+Ghrelin group, with 20 rats in each group. In the sham operation group, the cecum was separated after laparotomy, without ligation and perforation. In the sepsis group, the rats received cecal ligation puncture (CLP). In the sepsis+vagotomy group, the rats received CLP and vagotomy after laparotomy. In the sepsis+Ghrelin group, 100 μmol/L Ghrelin was intravenously injected after CLP immediately. The rats in the sepsis+vagotomy+Ghrelin group received CLP and vagotomy at the same time, then the Ghrelin was intravenously injected immediately with the same dose as the sepsis+Ghrelin group. Ten rats in each group were taken to observe their survival within 7 days. The remaining 10 rats were sacrificed 20 hours after the operation to obtain venous blood and small intestinal tissue. The condition of the abdominal intestine was observed. The injury of intestinal epithelial cells was observed with transmission electron microscopy. The contents of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in serum and small intestinal tissue were detected by enzyme-linked immunosorbent assay (ELISA). The brush border membrane vesicle (BBMV) was prepared, the levels of mRNA and protein expression of PepT1 in the small intestinal epithelium were detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and Western blotting. All rats in the sham operation group survived at 7 days after operation. The 7-day cumulative survival rate of rats in the sepsis group was significantly lower than that in the sham operation group (20% vs. 100%, P < 0.05). The cumulative survival rate of rats after Ghrelin intervention was improved (compared with sepsis group: 40% vs. 20%, P < 0.05), but the protective effect of Ghrelin was weakened after vagotomy (compared with sepsis+Ghrelin group: 10% vs. 40%, P < 0.05). Compared with the sham operation group, in the sepsis group, the small intestine and cecum were dull red, the intestinal tubules were swollen and filled with gas, the intestinal epithelial cells were seriously injured under transmission electron microscopy, the levels of TNF-α and IL-1β in serum and small intestinal were significantly increased, and the expression levels of PepT1 mRNA and protein in the small intestinal epithelium were significantly decreased. It indicated that the sepsis rat model was successfully prepared. After vagotomy, the intestinal swelling and gas accumulation became worse in septic rats, leading to the death of all rats. Compared with the sepsis group, the abdominal situation in the sepsis+Ghrelin group was improved, the injury of intestinal epithelial cells was alleviated, the serum and small intestinal TNF-α and IL-1β were significantly decreased [serum TNF-α (ng/L): 253.27±23.32 vs. 287.90±19.48, small intestinal TNF-α (ng/L): 95.27±11.47 vs. 153.89±18.15, serum IL-1β (ng/L): 39.16±4.47 vs. 54.26±7.27, small intestinal IL-1β (ng/L): 28.47±4.13 vs. 42.26±2.59, all P < 0.05], and the expressions of PepT1 mRNA and protein in the small intestinal epithelium were significantly increased [PepT1 mRNA (2-ΔΔCt): 0.66±0.05 vs. 0.53±0.06, PepT1 protein (PepT1/GAPDH): 0.80±0.04 vs. 0.60±0.05, both P < 0.05]. Compared with the sepsis+Ghrelin group, after vagotomy in the sepsis+vagotomy+Ghrelin group, the effect of Ghrelin on reducing the release of inflammatory factors in sepsis rats was significantly reduced [serum TNF-α (ng/L): 276.58±19.88 vs. 253.27±23.32, small intestinal TNF-α (ng/L): 144.28±12.99 vs. 95.27±11.47, serum IL-1β (ng/L): 48.15±3.21 vs. 39.16±4.47, small intestinal IL-1β (ng/L): 38.75±4.49 vs. 28.47±4.13, all P < 0.05], the up-regulated effect on the expression of PepT1 in small intestinal epithelium was lost [PepT1 mRNA (2-ΔΔCt): 0.58±0.03 vs. 0.66±0.05, PepT1 protein (PepT1/GAPDH): 0.70±0.02 vs. 0.80±0.04, both P < 0.05], and the injury of small intestinal epithelial cells was worse. Ghrelin plays a protective role in sepsis by promoting cholinergic neurons to inhibit the release of inflammatory factors, thereby promoting the transcription and translation of PepT1.

Acrylamide Neurotoxicity as a Possible Factor Responsible for Inflammation in the Cholinergic Nervous System.

Acrylamide (ACR) is a chemical compound that exhibits neurotoxic and genotoxic effects. It causes neurological symptoms such as tremors, general weakness, numbness, tingling in the limbs or ataxia. Numerous scientific studies show the effect of ACR on nerve endings and its close connection with the cholinergic system. The cholinergic system is part of the autonomic nervous system that regulates higher cortical functions related to memory, learning, concentration and attention. Within the cholinergic system, there are cholinergic neurons, anatomical cholinergic structures, the neurotransmitter acetylcholine (ACh) and cholinergic receptors. Some scientific reports suggest a negative effect of ACR on the cholinergic system and inflammatory reactions within the body. The aim of the study was to review the current state of knowledge on the influence of acrylamide on the cholinergic system and to evaluate its possible effect on inflammatory processes. The cholinergic anti-inflammatory pathway (CAP) is a neuroimmunomodulatory pathway that is located in the blood and mucous membranes. The role of CAP is to stop the inflammatory response in the appropriate moment. It prevents the synthesis and the release of pro-inflammatory cytokines and ultimately regulates the local and systemic immune response. The cellular molecular mechanism for inhibiting cytokine synthesis is attributed to acetylcholine (ACh), the major vagal neurotransmitter, and the α7 nicotinic receptor (α7nAChR) subunit is a key receptor for the cholinergic anti-inflammatory pathway. The combination of ACh with α7nAChR results in inhibition of the synthesis and release of pro-inflammatory cytokines. The blood AChE is able to terminate the stimulation of the cholinergic anti-inflammatory pathway due to splitting ACh. Accordingly, cytokine production is essential for pathogen protection and tissue repair, but over-release of cytokines can lead to systemic inflammation, organ failure, and death. Inflammatory responses are precisely regulated to effectively protect against harmful stimuli. The central nervous system dynamically interacts with the immune system, modulating inflammation through the humoral and nervous pathways. The stress-induced rise in acetylcholine (ACh) level acts to ease the inflammatory response and restore homeostasis. This signaling process ends when ACh is hydrolyzed by acetylcholinesterase (AChE). There are many scientific reports indicating the harmful effects of ACR on AChE. Most of them indicate that ACR reduces the concentration and activity of AChE. Due to the neurotoxic effect of acrylamide, which is related to the disturbance of the secretion of neurotransmitters, and its influence on the disturbance of acetylcholinesterase activity, it can be concluded that it disturbs the normal inflammatory response.

Role of Cholinergic Anti-Inflammatory Pathway in Protecting Sepsis-Induced Acute Lung Injury through Regulation of the Conventional Dendritic Cells.

Background The cholinergic anti-inflammatory pathway connects the immune response system and the nervous system via the vagus nerve. The key regulatory receptor is the α7-subtype of the nicotinic acetylcholine receptor (α7nAChR). Cholinergic anti-inflammatory pathway has been proved to be effective in suppressing the inflammation responses in acute lung injury (ALI). Dendritic cells (DCs), the important antigen-presenting cells, also express the α7nAChR. Past studies have indicated that reducing the quantity of mature conventional DCs and inhibiting the maturation of pulmonary DCs may prove effective for the treatment of ALI. However, the effects of cholinergic anti-inflammatory pathway on maturation, function, and quantity of DCs and conventional DCs in ALI remain unclear. Objective It was hypothesized that cholinergic anti-inflammatory pathway may inhibit the inflammatory response of ALI by regulating maturation, phenotype, and quantity of DCs and conventional DCs. Methods GTS-21 (GTS-21 dihydrochloride), an α7nAchR agonist, was prophylactically administered in sepsis-induced ALI mouse model and LPS-primed bone marrow-derived dendritic cells. The effects of GTS-21 were observed with respect to maturation, phenotype, and quantity of DCs, conventional DCs, and conventional DCs2 (type 2 conventional DCs) and the release of DC-related proinflammatory cytokines in vivo and in vitro. Results The results of the present study revealed that GTS-21 treatment decreased the maturation of DCs and the production of DC-related proinflammatory cytokines in vitro and in sepsis-induced ALI mouse model; it reduced the quantity of CD11c+MHCII+ conventional DCs and CD11c+CD11b+ conventional DCs2 in vivo experiment. Conclusions Cholinergic anti-inflammatory pathway contributes to the reduction in the inflammatory response in ALI by regulating maturation, phenotype, and quantity of DCs, conventional DCs, and conventional DCs2.

Cholinergic anti-inflammatory pathway plays negative regulatory role in early inflammatory and immune responses in septic rats

To investigate the role of cholinergic anti-inflammatory pathway (CAP) in neuro-regulation of inflammatory and immune response in the early stage of sepsis. Sixty-four SD rats were randomly divided into control Group (n=8) with normal feeding without any treatment; sham operation group (n=8) with laparotomy but without cecal ligation and puncture (CLP), followed by intraperitoneal injection 50 mg/kg piperacillin 3 times a day for 3 consecutive days; and sepsis group (n=48) with CLP-induced sepsis. The rat models of sepsis were randomized into model groups (n=16) with intraperitoneal injection of piperacillin (50 mg/kg) and normal saline (1 mL/100 g) for 3 times a day for 3 days; GTS-21 group (n=16) with additional intraperitoneal injection of 4 mg/kg GTS-21 (once a day for 3 days); and methyllycaconitine (MLA) group (n=16) with intraperitoneal injection of MLA (4.8 mg/kg) in addition to piperacillin (once a day for 3 days). Murine Sepsis Score (MSS) of the rats and short-range HRV analysis were recorded. Three days later, the rats were sacrificed and serum levels of TNF-α, IL-1α, IL-10, IL-6, HMGB1, and sCD14 were measured with ELISA. The percentages of CD4+CD25+ Treg and TH17 lymphocytes and their ratios were measured using flow cytometry. Compared with the control rats, the septic rats had significantly increased MSS scores and lowered HRV indexes (SDNN, RMSSD, HF, SD1, and SD2; P &lt; 0.05); treatment with GTS-21 significantly decreased while MLA increased MSS scores (P &lt; 0.05), but neither of them obviously affected HRV of the rats. Serum levels TNF-α, IL-1α, IL-10, IL-6, HMGB1, and sCD14 and the percentages of CD4+CD25+ Treg and TH17-positive lymphocytes were significantly higher and Treg/TH17 ratio was significantly lower in the septic rats compared with those in the control group (P &lt; 0.05); treatment with GTS-21 significantly decreased the levels of serum levels of TNF-α, IL-1α, IL-6, HMGB1, and sCD14 and TH17 lymphocyte percentage (P &lt; 0.05), whereas MLA treatment significantly increased serum levels of TNF-α, IL-1α, IL-10, IL-6, HMGB1, and sCD14 and the percentages of CD4+ CD25+ Treg and TH17-positive lymphocytes and decreased Treg/TH17 ratio in the septic rats (P &lt; 0.05). CAP plays negative regulatory role in early inflammatory and immune response to sepsis, and some of the HRV indicators can well reflect the regulatory effect of CAP on inflammation and immunity in the septic rats.

Research progress on cholinergic anti-inflammatory pathway in acute respiratory distress syndrome

Inflammation is an important defense mechanism against external pathogen invasion and tissue damage. However, when the body is in a persistent inflammatory state, excessive accumulation of neutrophils may cause further severely tissue damage, leading to inflammation-related diseases. The cholinergic anti-inflammatory pathway (CAP) links the nervous system and the immune system closely together. Stimulation of the vagus nerve can release acetylcholine (ACh) which then binds to cholinergic receptors on the surface of immune cells and suppress the release of pro-inflammatory cytokines, so as to reduce inflammatory response and facilitate tissue recovery. Acute respiratory distress syndrome (ARDS) is a highly disabling and even fatal clinical syndrome. The pathological manifestations are acute and diffuse inflammatory lung injury. Reducing lung injury in ARDS patients is still a hot topic in recent years. This review summarized the role of CAP in ARDS induced by different models and its possible mechanisms. Key words: Cholinergic anti-inflammatory pathway; Vagus nerve; Acute respiratory distress syndrome; Inflammation

Neuro-immune interactions in cholinergic antiinflammatory pathway

More and more researches suggest that the nervous and immune systems actively interact. Investigation of the mechanisms that underlie the development of septic shock led to discovery of a qualitatively new type of neuro-immune interactions - the cholinergic anti-inflammatory pathway involving the vagus nerve. However, despite the electrical stimulation of the vagus nerve that is already actively used in order to relieve the symptoms of some autoimmune conditions, many molecular and cellular aspects of the cholinergic anti-inflammatory pathway remain unknown or controversial. This review discusses the mechanisms of the reception of inflammatory mediators by vagal afferent fibers and nervous cells in the area postrema, the nerve centers presumably involved in the processing of immune information, the efferent parasympathetic effects on the immune system, in particular, the release of pro-inflammatory cytokines by spleen macrophages, as well as the role of cholinergic anti-inflammatory pathway in maintaining homeostasis in the body.

Effect of intraperitoneally injected dexmedetomidine on abdominal adhesions in rats and the role of cholinergic anti-inflammatory pathway

Objective To evaluate the effect of intraperitoneally injected dexmedetomidine on abdominal adhesions in rats and the role of cholinergic anti-inflammatory pathway. Methods Forty clean-grade healthy adult male Sprague-Dawley rats, weighing 220-250 g, were divided into 4 groups (n = 10 each) using a random number table method: sham operation group (Sham group), abdominal adhesion group (AA group), dexmedetomidine group (DEX group) and dexmedetomidine plus methyllycaconitine group (DEX-M group). The rat model of abdominal adhesions was established by cecal friction method.In Sham group, abdominal cavity was only opened and then sutured.Normal saline 2 ml was injected into the abdominal cavity and tail vein in group AA.In DEX and DEX-M groups, normal saline 2 ml and α7 nicotinic acetylcholine receptor antagonist methyllycaconitine 2.4 μg/g (dissolved in 2 ml normal saline) were injected, respectively, and dexmedetomidine 10 μg/kg (dissolved in 2 ml normal saline) was intraperitoneally injected at the same time.The abdominal incision was opened under anesthesia at 7 days after establishing the model to observe the formation of abdominal adhesion, Phillips method was used for scoring, and enzyme-linked immunosorbent assay was used to determine the transforming growth factor-beta1 (TGF-β1) concentrations in ascites and tumor necrosis factor-alpha (TNF-α) concentrations in serum.The rats were then sacrificed, and the caecum tissue and its contralateral peritoneum and adhesion fibrous strips were obtained for examination of the pathological changes with a light microscope. Results Compared with group Sham, the abdominal adhesion score and serum TNF-α concentrations were significantly increased in AA and DEX-M groups, and the TGF-β1 concentration in ascites was significantly increased in AA, DEX and DEX-M groups (P 0.05), and the pathological changes of caecum tissue, contralateral peritoneum and adhesion fibrous strips were accentuated in group DEX. Conclusion Intraperitoneally injected dexmedetomidine can mitigate abdominal adhesions, and the mechanism is related to activating cholinergic anti-inflammatory pathway and reducing systemic inflammatory response in rats. Key words: Dexmedetomidine; Injections, intraperitoneal; Tissue adhesions; Cholinergic anti-inflammatory

Activation of \u03b17 Nicotinic Acetylcholine Receptor Ameliorates Zymosan-Induced Acute Kidney Injury in BALB/c Mice

Zymosan, a natural compound, provokes acute peritonitis and multiple organ dysfunction that affects the kidney, beside other organs via exaggerated inflammatory response. The aim of the present study is to test the role of cholinergic anti-inflammatory pathway (CAP) in alleviating acute kidney injury (AKI) induced by zymosan in BALB/c mice, using galantamine, a cholinesterase inhibitor, known to act via α7 nicotinic acetylcholine receptor (α7 nAChR) to stimulate CAP. Galantamine verified its anti-inflammatory effect by elevating acetylcholine (ACh) level, while abating the interleukin-6/ janus kinase 2 (Y1007/1008)/ signal transducer and activator of transcription 3 (Y705) (IL-6/ pY(1007/1008)-JAK2/ pY705-STAT3) inflammatory axis, with a consequent inhibition in suppressor of cytokine signaling 3 (SOCS3). This effect entails also the nuclear factor-kappa B (p65)/ high mobility group box protein-1/ (NF-κB (p65)/ HMGB-1) signaling pathway. Furthermore, the reno-curattive effect of galantamine was associated by a reduction in plasma creatinine (Cr), cystatin (Cys)-C, IL-18, and renal neutrophil gelatinase-associated lipocalin (NGAL), as well as an improved histopathological structure. Blocking the α7 nAChR by methyllycaconitine abolished the beneficial effect of galantamine to document the involvement of this receptor and the CAP in the amelioration of AKI induced by zymosan.

Role of cholinergic anti-inflammatory pathway in dexmedetomidine pretreatment-induced reduction of acute lung injury in a rat model of intestinal ischemia-reperfusion

Objective To evaluate the role of cholinergic anti-inflammatory pathway in dexmedetomidine pretreatment-induced reduction of acute lung injury in a rat model of intestinal ischemia-reperfusion (I/R). Methods Twenty-four healthy male Sprague-Dawley rats, aged 2-3 months, weighing 200-250 g, were divided into 4 groups (n=6) using a random number table method: sham operation group (S group), intestinal I/R group (II/R group ), dexmetomidine group (DEX group) and α7 nicotinic acetylcholine receptor antagonist α-bungarotoxin (α-BGT) group (α-BGT group). Intestinal I/R was produced by occlusion of the superior mesenteric artery (SMA) for 60 min followed by 120 min of reperfusion in anesthetized rats.Dexmetomidine 5 μg·kg-1·h-1 was injected via the tail vein at 1 h before operation in DEX group and α-BGT group.α-BGT 1 μg/kg was intraperitoneally injected at 15 min before dexmetomidine injection in α-BGT group.Rats were sacrificed at 120 min of reperfusion, and lung tissues were obtained for microscopic examination of pathological changes (with a light microscope) and for determination of wet/dry weight ratio (W/D ratio), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) contents (using enzyme-linked immunosorbent assay), malondialdehyde (MDA) content (using thiobarbital acid method) and superoxide dismutase (SOD) activity (by xanthine oxidase method). Results Compared with group S, the W/D ratio and contents of MDA, TNF-α and IL-6 were significantly increased, and the SOD activity was decreased in II/R and α-BGT groups, and TNF-α and IL-6 contents were significantly increased in group DEX (P<0.05). Compared with group II/R, the W/D ratio and contents of MDA, TNF-α and IL-6 were significantly decreased, SOD activity was increased (P<0.05), and the pathological changes were significantly attenuated in group DEX.Compared with group DEX, the W/D ratio and contents of MDA, TNF-α and IL-6 were significantly increased, SOD activity was decreased (P<0.05), and the pathological changes were accentuated in group α-BGT. Conclusion Activation of cholinergic anti-inflammatory pathway is involved in the mechanism by which dexmedetomidine pretreatment reduces acute lung injury in a rat model of intestinal I/R. Key words: Acetylcholine; Dexmetomidine; Reperfusion injury; Intestines; Hespiratory distress syndrome, adult

Role of Cholinergic Anti-Inflammatory Pathway in Treatment of Intestinal Ischemia-Reperfusion Injury by Electroacupuncture at Zusanli.

Electroacupuncture (EA) at Zusanli is a widely used method for the treatment of intestinal ischemic disease. The current study attempts to investigate the possible mechanism from the point of cholinergic anti-inflammatory pathway (CAP) in rats. Thirty rats were divided into five groups: control group, I/R group, EA group (I/R + EA), PNU group (I/R + α7 nAChR agonist), and α-BGT group (I/R + EA + α7 nAChR antagonist). EA and medicine injection were performed immediately after ischemia. After 2 h of reperfusion, blood and intestine samples were collected and intestinal histopathological score, mRNA expression of mucosal α7 nAChR and NF-κBp65, and serum cytokine levels (IL-6, TNF-α) were examined. Compared with the I/R group, the EA group and PNU group could significantly attenuate the mucosal damage, promote α7 nAChR mRNA expression, and reduce levels of NF-κBp65, IL-6, and TNF-α. Compared with the EA group, α7 nAChR mRNA was decreased, while concentrations of NF-κBp65, IL-6, and TNF-α increased in the α-BGT group. EA at Zusanli could inhibit NF-κBp65 and proinflammatory cytokines production after intestinal I/R injury; its mechanism may be related to the cholinergic anti-inflammatory pathway.

Liang-Ge-San, a classic traditional Chinese medicine formula, protects against lipopolysaccharide-induced inflammation through cholinergic anti-inflammatory pathway

Liang-Ge-San (LGS) is a classic formula in traditional Chinese medicine, which is widely used to treat acute lung injury (ALI), pharyngitis and amygdalitis in clinic. However, the underlying mechanisms remain poorly defined. In this study, we discovered that LGS exerted potent anti-inflammatory effects in lipopolysaccharide (LPS)-induced inflammation. We found that LGS significantly depressed the production of IL-6 and TNF-α in LPS-stimulated RAW 264.7 macrophage cells. The degradation and phosphorylation of IκBα and the nuclear translocation of NF-κB p65 were also inhibited. Moreover, LGS activated α7 nicotinic cholinergic receptor (α7nAchR). The blockage of α7nAchR by selective inhibitor methyllycaconitine (MLA) or α7nAchR siRNA attenuated the inhibitory effects of LGS on IκBα, NF-κB p65, IL-6 and TNF-α. Critically, LGS significantly inhibited inflammation in LPS-induced ALI rats through the activation of NF-κB signaling pathway. However, these protective effects could be counteracted by the treatment of MLA. Taken together, we first demonstrated anti-inflammatory effects of LGS both in vitro and in vivo through cholinergic anti-inflammatory pathway. The study provides a rationale for the clinical application of LGS as an anti-inflammatory agent and supports the critical role of cholinergic anti-inflammatory pathway in inflammation.

Abstract 33: Vagus Nerve Stimulation for Acute Stroke Treatment: Role of Cholinergic Anti-Inflammatory Pathway

Introduction: Electrical stimulation of the cervical vagus nerve is neuroprotective after MCAO in rats; decrease in infarct volume ranges from ~40% (using surgically implanted electrodes) to ~30% (using clinically applicable non-invasive devices). The exact mechanism of vagus nerve stimulation (VNS)-induced neuroprotection is not known, but so far cerebral blood flow-related mechanism has been eliminated. VNS attenuates systemic inflammation via activation of alpha7 nicotinic acetylcholine receptors (α7 nAChR) on macrophages. We hypothesized that α7 nAChR -mediated anti-inflammatory effect plays a mechanistic role in VNS-induced neuroprotection after cerebral ischemia. Methods: Focal ischemia was induced by 2 hour transient MCAO in Wistar rats and verified by &gt;60% drop in baseline cerebral blood flow. Methyllycaconitine (MLA; 10 mg/kg, IP) was used to block α7 nAChRs. Animals were randomly assigned to one of four experimental groups: sham stimulation/vehicle, sham stimulation/MLA, VNS/vehicle, VNS/MLA (n=6 in each). VNS was initiated 30 minutes after MCAO and delivered for 1 hour via implanted electrodes, using previously published stimulation parameters. Animals were euthanized 24 hours later to measure infarct volume by TTC. In separate cohorts, immunohistochemistry was used to assess the changes in brain levels of α7 nAChR-related cytokines, TNF-α and high mobility group box protein 1 (HMGB1), in sham-stimulated and VNS groups. Results: Mean infarct volume in sham-stimulated and VNS groups were 43.83 ± 1.53% and 25.33 ± 3.39%, respectively (p&lt;0.05). MLA abolished the neuroprotective effect of VNS; after MLA treatment mean infarct volume in sham-stimulated and VNS groups were 45.24 ± 4.78% and 48.58 ± 2.78%, respectively (p=n.s.). MLA alone had no effect on ischemic outcome; there was no difference in infarct volume between MLA- treated and untreated sham-stimulated animals (p=n.s.). Ischemia-induced elevation in TNF-α and decrease in HMGB1 levels were completely reversed by VNS as early as 3 hours after ischemia. Conclusion: This study shows that anti-inflammatory mechanisms via nicotinic acetylcholine receptor-mediated signaling play a role in protective effect of VNS against ischemic tissue damage.

The role of cholinergic anti-inflammatory pathway in acetic acid-induced colonic inflammation in the rat

The “cholinergic anti-inflammatory pathway” provides neurological modulation of cytokine synthesis to limit the magnitude of the immune response. This study aimed to evaluate the impact of the cholinergic anti-inflammatory pathway on the extent of tissue integrity, oxidant-antioxidant status and neutrophil infiltration to the inflamed organ in a rat model of acetic acid-induced colitis. Colitis was induced by intrarectal administration of 5% acetic acid (1ml) to Sprague–Dawley rats (200–250g; n=7–8 per group). Control group received an equal volume of saline intrarectally. The rats were treated with either nicotine (1mg/kg/day) or huperzine A (0.1mg/kg/day) intraperitoneally for 3days. After decapitation, the distal colon was scored macroscopically and microscopically. Tissue samples were used for the measurement of malondialdehyde (MDA) and glutathione (GSH) levels, and myeloperoxidase (MPO) activity. Formation of reactive oxygen species was monitored by using chemiluminescence (CL). Nuclear factor (NF)-κB expression was evaluated in colonic samples via immunohistochemical analysis. Trunk blood was collected for the assessment of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-10, resistin and visfatin levels. Both nicotine and huperzine A reduced the extent of colonic lesions, increased colonic MDA level, high MPO activity and NF-κB expression in the colitis group. Elevation of serum IL-1β level due to colitis was also attenuated by both treatments. Additionally, huperzine A was effective to reverse colitis-induced high lucigenin-enhanced CL values and serum TNF-α levels. Colitis group revealed decreased serum visfatin levels compared to control group which was completely reversed by nicotine. In conclusion, modulation of the cholinergic system either by nicotine or ACh esterase inhibition improved acetic acid-induced colonic inflammation as confirmed by macroscopic and microscopic examination and biochemical assays.

Modulatory role of cholinergic anti-inflammatory pathway on the hypothalamic–pituitary unit activity during an immune challenge

Practice patterns related to intraoperative fluid administration and vasopressor use have potentially evolved over recent years. However, the extent of such changes and their association with perioperative outcomes, such as the development of acute kidney injury (AKI), have not been studied.We performed a retrospective analysis of major abdominal surgeries in adults across 26 US hospitals between 2015 and 2019. The primary outcome was AKI as defined by the Kidney Disease Improving Global Outcomes definition (KDIGO) using only serum creatinine criteria. Univariable linear predictive additive models were used to describe the dose-dependent risk of AKI given fluid administration or vasopressor use.Over the study period, we observed a decrease in the volume of crystalloid administered, a decrease in the proportion of patients receiving more than 10 ml kg−1 h−1 of crystalloid, an increase in the amount of norepinephrine equivalents administered, and a decreased duration of hypotension. The incidence of AKI increased between 2016 and 2019. An increase of crystalloid administration from 1 to 10 ml kg−1 h−1 was associated with a 58% decreased risk of AKI.Despite decreased duration of hypotension during the study period, decreased fluid administration and increased vasopressor use were associated with increased incidence of AKI. Crystalloid administration below 10 ml kg−1 h−1 was associated with an increased risk of AKI. Although no causality can be concluded, these data suggest that prevention and treatment of hypotension during abdominal surgery with liberal use of vasopressors at the expense of fluid administration is associated with an increased risk of postoperative AKI.

The role of cholinergic anti-inflammatory pathway in immune stimulation

The role of cholinergic anti-inflammatory pathway in immune stimulation

Role of cholinergic anti-inflammatory pathway in regulating host response and its interventional strategy for inflammatory diseases

The cholinergic anti-inflammatory pathway (CAP) is a neurophysiological mechanism that regulates the immune system. The CAP inhibits inflammation by suppressing cytokine synthesis via release of acetylcholine in organs of the reticuloendothelial system, including the lungs, spleen, liver, kidneys and gastrointestinal tract. Acetylcholine can interact with alpha7 nicotinic acetylcholine receptors (alpha7 nAchR) expressed by macrophages and other cytokine producing cells, down-regulate pro-inflammatory cytokine synthesis and prevent tissue damage. Herein is a review of the neurophysiological mechanism in which the CAP regulates inflammatory response, as well as its potential interventional strategy for inflammatory diseases.