Research progress on the effect of α7 nicotinic acetylcholine receptor on perioperative neurocognitive function / 解放军医学杂志

α7 nicotinic acetylcholine receptor(α7nAChR)is widely expressed in the central nervous system and immune system,and plays a neuro-immunoregulatory role.On the one hand,α7nAChR is involved in the transmission of neurotransmitters,the conduction of excitatory signals and the maintenance of synaptic plasticity,which is of great significance for maintaining the normal and stable neurocognitive function.On the other hand,as an important part of the cholinergic anti-inflammatory pathway,α7nAChR is involved in the regulation of physiological and pathological processes such as inflammatory response,oxidative stress,apoptosis and autophagy in the central system,and plays an immunomodulatory and neuroprotective role,thus being potential target for improving perioperative neurocognitive function.This article reviews the biological characteristics of α7nAChR and its effect on perioperative neurocognitive function,in order to provide ideas and methods for clinical improvement of perioperative neurocognitive function in surgical patients.

Effect of activating α7 nicotinic acetylcholine receptor on learning and memory function and microglia in traumatic brain injury model rat / 中华行为医学与脑科学杂志

Objective:To explore the effects of activating α7 nicotinic acetylcholine receptor(α7nAChR)on cognitive function and polarization of hippocampal microglia in traumatic brain injury (TBI) rats.Methods:Totally 36 male SD rats with 6-8 weeks old were randomly divided into Sham group ( n=12), TBI group ( n=12), TBI+ α7nAChR agonist group ( n=6) and TBI+ α7nAChR antagonist group( n=6). The TBI model was established by the " free fall impact" method. From the 4th to 6th day after modeling, mice in the TBI+ α7nAChR agonist group were intraperitoneally injected with α7nAChR agonist PNU-282987 (3 mg/kg). Rats in TBI+ α7nAChR antagonist group were intraperitoneally injected with α7nAChR antagonist methyllycaconitine citrate (5 mg/kg) first, then 45 minutes later they were injected with α7nAChR agonist PNU-282987 (3 mg/kg). Rats in the TBI group and Sham group were intraperitoneally injected with an equal volume of 0.9% sodium chloride solution. Morris water maze test was used to evaluate the learning and memory function of rats. Immunofluorescence staining was used to observe the ionized calcium binding adapter molecule 1 (Iba-1)(a marker for microglia) and arginase 1 (Arg-1)(a marker for M2 microglia). Western blot was used to detect the protein level of Arg-1 in hippocampal tissue. Statistical analysis was performed using GraphPad Prism 9 software. Independent sample t test was used for comparison between two groups, one-way ANOVA was used for comparison among multiple groups, and Tukey test was used for multiple comparison. Results:The results of the water maze test showed that after 7 days of modeling, there was a statistical difference in the escape latency among the 4 groups of rats ( F=6.134, P<0.05). There was no statistical difference in the escape latency between the TBI group and the TBI+ α7nAChR antagonist group( P>0.05), but the both were higher than that of the Sham group (both P<0.05). The escape latency of the TBI+ α7nAChR agonist group((31.87±9.01)s) was shorter than that of the TBI group((56.75±2.62)s) and the TBI+ α7nAChR antagonist group((60.00±0.00)s) (both P<0.05). The results of immunofluorescence staining showed that there were statistical differences in the fluorescence intensity and cell numbers of Arg-1 + /Iba-1 + among the four groups ( F=17.37, 9.33, both P<0.05). The immune fluorescence intensity (0.27±0.03) and cell numbers (21.67±4.41) of Arg-1 + /Iba-1 + in the TBI+ α7nAChR agonist group were higher than those in the TBI group((0.14±0.03), (11.33±2.60)) and TBI+ α7nAChR antagonist group((0.10±0.03), (7.67±1.20)) (all P<0.05). The results of Western blot showed that there was a statistical difference in the level of Arg-1 protein in hippocampus among the 4 groups ( F=8.323, P=0.001). There was no significant difference in the level of Arg-1 protein between the TBI group and the TBI+ α7nAChR antagonist group( P>0.05), and the level of Arg-1 protein in the TBI+ α7nAChR agonist group(1.06±0.22) was higher than that in the TBI group(0.60±0.13) and TBI+ α7nAChR antagonist group(0.35±0.10) (both P<0.05). Conclusion:Activating α7nAChR can promote the polarization of M2 type microglia in rat hippocampal tissue and improve the learning and memory function of TBI rats.

Role of α7nAChR in penehyclidine hydrochloride-induced reduction of endotoxin-induced acute lung injury in mice / 中华麻醉学杂志

Objective:To evaluate the role of α7 nicotinic acetylcholine receptor (α7nAChR) in penehyclidine hydrochloride-induced reduction of endotoxin-induced acute lung injury (ALI) in mice.Methods:Forty SPF healthy male C57BL/6 mice, aged 6-8 weeks, weighing 18-25 g, were divided into 4 groups ( n=10 each) using a random number table method: control group (group C), ALI group, penehyclidine hydrochloride group (PHC group), and α7nAChR inhibitor MLA group (MLA group). ALI was induced by intraperitoneal injection of lipopolysaccharide 15 mg/kg in anesthetized animals, while normal saline was given instead in group C. In PHC group, penehyclidine hydrochloride 2 mg/kg was intraperitoneally injected at 30 min before developing the model. MLA 10 mg/kg was intraperitoneally injected at 10 min before administration of penehyclidine hydrochloride in MLA group. Mice were sacrificed at 6 h after lipopolysaccharide administration, and lung tissues were collected for microscopic examination of the pathological changes (by HE staining) and for determination of the wet/dry weight ratio (W/D ratio), content of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β) and IL-10 (by enzyme-linked immunosorbent assay) and expression of α7nAChR (by Western blot). Results:Compared with C group, the W/D ratio and contents of TNF-α and IL-1β were significantly increased, the content of IL-10 was decreased, and the expression of α7nAChR was up-regulated in ALI, PHC and MLA groups ( P<0.05). Compared with ALI group, the W/D ratio and contents of TNF-α and IL-1β were significantly decreased, the content of IL-10 was increased, and the expression of α7nAChR was up-regulated in PHC group ( P<0.05). Compared with PHC group, the W/D ratio and contents of TNF-α and IL-1β were significantly increased, the content of IL-10 was decreased, and the expression of α7nAChR was down-regulated in MLA group ( P<0.05). Compared with ALI group, the pathological changes of lung tissues were significantly mitigated in PHC group, while this effect of PHC was partially reversed by α7nAChR inhibitor MLA. Conclusions:α7nAChR is involved in penehyclidine hydrochloride-induced reduction of endotoxin-induced ALI in mice.

Expression and function of α7 nicotinic acetylcholine receptor in thymocytes of myasthenia gravis patients / 中国胸心血管外科临床杂志

@#Objective    To investigate the expression of α7 nicotinic acetylcholine receptor (α7 nAChR) in thymocytes of patients with myasthenia gravis (MG) and its effect on cytokine secretion and T cell proliferation. Methods    Patients with MG who underwent expanded thoracoscopic thymectomy in the Comprehensive Diagnosis and Treatment Center of the Henan Provincial People’s Hospital from June 2021 to June 2022 were selected and allocated to a MG group. Patients who underwent partial thymectomy to expose the surgical field during the cardiac disease surgery from June 2021 to September 2022 in the Department of Adult Cardiac Surgery of Fuwai Huazhong Cardiovascular Hospital were selected as the control group. Thymic single cell suspensions were prepared from MG and control groups, and the expression of α7 nAChR in thymocytes of the two groups was detected by real-time polymerase chain reaction and Western blotting. Then CD3/CD28 monoclonal antibody coupled with magnetic beads was used to induce T cell activation, and the levels of cytokines interferon-gamma (IFN-γ), tumor necrosis factor-α (TNF-α), interleukin-4 (IL-4), IL-6, IL-10, IL-17, and IL-21 in thymocytes of the two groups were detected by enzyme-linked immunosorbent assay (ELISA). The activated T cells of the MG group were divided into a blank control group, an α7 nAChR antagonist group, and an α7 nAChR agonist group according to different treatment methods. After 72 hours of culture, IFN-γ, TNF-α, IL-4, IL-6, IL-10, IL-17, and IL-21 expression levels in the culture supernatant were measured by ELISA. Afterwards, CD4-PE and CD8-APC antibodies were added, and the proliferation of T cell subsets was detected by flow cytometry. Results    A total of 10 MG patients were collected, including 3 males and 7 females with an average age of 19.25±6.28 years; and 15 control patients were collected, including 6 males and 9 females with an average age of 26.18±6.77 years. Compared with the control group, the mRNA and protein levels of α7 nAChR in the thymocytes of MG group were decreased, and the expression levels of IFN-γ, TNF-α, IL-4, IL-6 and IL-21 in the supernatant were increased (P<0.05), but there was no statistical difference in the expression of IL-10 and IL-17 (P>0.05). The cell-culture experiment showed that compared with the blank control group, the levels of IFN-γ, TNF-α, IL-6 and IL-21 secreted by T cells in the α7 nAChR antagonist group were increased (P<0.05), while they were decreased in the α7 nAChR agonist group (P<0.05). There was no statistical difference in the secretion levels of IL-4, IL-10 or IL-17 among the three groups (P>0.05). CD4+ T and CD8+ T cells in the α7 nAChR agonist group were significantly less than those in the blank control group and α7 nAChR antagonist group (P<0.001), while they were significantly more in the α7 nAChR antagonist group than those in the blank control group (P<0.001). Conclusion    The expression of α7 nAChR in thymocytes of MG patients is decreased, and α7 nAChR may be involved in the inflammatory response in thymocytes and thus in thymic function.

Research progress on α7 nicotinic acetylcholine receptor in lung cancer / 中国胸心血管外科临床杂志

@#Lung cancer is one of the most prevalent and deadly malignances worldwide. Cigarette smoking has been identified to be the major risk factor of lung cancer, and nicotine is one of the most harmful components in tobacco smoke. Nicotinic acetylcholine receptors (nAChRs) are universally expressed in mammalian cells, including tumor cells, and perform various critical biological functions. α7nAChR, an important member of nAChRs family, possesses a high affinity for nicotine and plays a core role in the nicotine-mediated lung cancer cell proliferation, angiogenesis, invasion and metastasis. Nowadays, lots of α7nAChR antagonists have been found to inhibit lung cancer cell proliferation, invasion and angiogenesis in vitro and in vivo, and therefore prevented disease progression. These studies indicated that α7nAChR might be a potential target in treating lung cancer. In this review, we summarized the current researches on α7nAChR in the progress of lung cancer.

Mechanism and Application of α7 nAChR in Cholinergic Antiinflammatory Pathway / 中国生物化学与分子生物学报

Cholinergic anti-inflammatory pathway in which acetylcholine released as the neurotransmitter, plays an important role in nerve-immune regulation. In this pathway, with the vagus nerve in the central nervous system as a starting point, the alpha 7 nicotinic acetylcholine receptor (α7 nAChR) on the surface of immune cell membrane is the key functional part. The interaction between electrical and chemical signals regulates the inflammation in the body via modulation of the JAK-STAT3, PI3K-Akt and other signaling pathways and the nuclear translocation of NF-κB, leading to inhibition of the release of pro-inflammatory factors and promotion of the release of anti-inflammatory factors. However, the detailed mechanism is far from clear. Studies have shown that the cholinergic anti-inflammatory pathway can be activated by drug targeting α7 nAChR and electrical stimulation of vagus nerve. Activation of α7 nAChR has the advantages of simple operation, less damage and significant effect. The commonly used drugs are selective agonists such as PNU282987 and GTS-21, and non-selective agonists such as nicotine. And this method has been found to play a role in the treatment of peripheral organ inflammatory diseases such as sepsis, ischemia-reperfusion injury, gastroenteritis, osteoarthritis and autoimmune diseases. As a key factor in the cholinergic anti-inflammatory pathways, α7 nAChR has become a potential therapeutic target for many inflammatory diseases. This paper reviewed the anti-inflammatory mechanism and activation mode of α7 nAChR involved in cholinergic anti-inflammatory pathway, as well as its application in inflammatory diseases in recent years, which may provide a reference for future research on its detailed mechanism of action and potential application as a new therapeutic target.

Left-sided vagus nerve stimulation improves cardiopulmonary resuscitation outcomes in rats as effectively as right-sided vagus nerve stimulation / 世界急诊医学杂志（英文）

@#BACKGROUND: Our group previously reported that right-sided vagus nerve stimulation (RVNS) significantly improved outcomes after cardiopulmonary resuscitation (CPR) in a rat model of cardiac arrest (CA). However, whether left-sided vagus nerve stimulation (LVNS) could achieve the same effect as RVNS in CPR outcomes remains unknown. METHODS: A rat model of CA was established using modified percutaneous epicardial electrical stimulation to induce ventricular fibrillation (VF). Rats were treated with LVNS or RVNS for 30 minutes before the induction of VF. All animals were observed closely within 72 hours after return of spontaneous circulation (ROSC), and their health and behavior were evaluated every 24 hours. RESULTS: Compared with those in the RVNS group, the hemodynamic measurements in the LVNS group decreased more notably. Vagus nerve stimulation (VNS) decreased the serum levels of tumor necrosis factor-alpha (TNF-α) and the arrhythmia score, and attenuated inflammatory infiltration in myocardial tissue after ROSC, regardless of the side of stimulation, compared with findings in the CPR group. Both LVNS and RVNS ameliorated myocardial function and increased the expression of α-7 nicotinic acetylcholine receptor in the myocardium after ROSC. Moreover, a clear improvement in 72-hour survival was shown with VNS pre-treatment, with no significant difference in efficacy when comparing the laterality of stimulation. CONCLUSIONS: LVNS may have similar effects as RVNS on improving outcomes after CPR.

Toxicity and Efficacy of Water-eluted Fraction from Siegesbeckiae Herba Against Human Embryonic Lung Fibroblasts / 中国实验方剂学杂志

Objective:To detect the toxicity of water-eluted fraction from Siegesbeckiae Herba （SWEF） at different concentrations against MRC-5 human embryonic lung fibroblasts and its impacts on the expression of <italic>α</italic>7 nicotinic acetylcholine receptor （<italic>α</italic>7nAChR） and inflammatory factors， so as to figure out the active components responsible for toxicity and efficacy. Method:The toxicities of SWEF at 1， 6， 10， 20， and 50 g·L^-1 against MRC-5 cells were determined by cell counting kit-8 （CCK-8） assay combined with flow cytometry and Trypan blue staining. The changes in <italic>α</italic>7nAChR expression and inflammatory factor levels before and after <italic>α</italic>7nAChR gene silencing were detected to reveal the pharmacodynamic effect of SWEF on MRC-5 cells. Result:SWEF （≥6 g·L^-1） obviously inhibited the viability of MRC-5 cells （<italic>P</italic><0.01） and promoted their apoptosis and necrosis （<italic>P</italic><0.01）， with the half-maximal inhibitory concentration （IC₅₀） being 6.03 g·L^-1. The determination of <italic>α</italic>7nAChR expression and inflammatory factor levels in MRC-5 cells showed that SWEF contained <italic>α</italic>7nAChR agonist-like substance， which enhanced <italic>α</italic>7nAChR mRNA and protein expression （<italic>P</italic><0.05， <italic>P</italic><0.01） and decreased the inflammatory factor levels （<italic>P</italic><0.05， <italic>P</italic><0.01）. SWEF down-regulated the inflammatory factors possibly by re-regulating <italic>α</italic>7nAChR mRNA expression， exhibiting a negative correlation between them （<italic>P</italic><0.01）. Conclusion:SWEF （≥6 g·L^-1） is highly toxic to MRC-5 cells. Pharmacodynamic studies have confirmed that <italic>α</italic>7nAChR agonist-like substance contained in SWEF was responsible for the elevated <italic>α</italic>7nAChR expression and reduced inflammatory cytokines. It is inferred that excessive <italic>α</italic>7nAChR agonist-like substance may trigger the toxicity of<italic> </italic>Siegesbeckiae Herba.

Effect of Huanglian Jiedutang on Learning and Memory Ability and Cholinergic System in AD Rats Induced by Aβ1-42 / 中国实验方剂学杂志

Objective:To investigate the effects of Huanglian Jiedutang on learning and memory ability and the cholinergic system in Alzheimer's disease（AD） rats induced by amyloid <italic>β</italic>-protein（A<italic>β</italic>）_1-42. Method:Sixty male SD rats were divided into normal group， model group， huperzine A group （2.1×10^-5 g·kg^-1）， high-， medium- and low dose of Huanglian Jiedutang groups （6，3，1.5 g·kg^-1）. AD rat model was replicated by hippocampal injection of A<italic>β</italic>_1-42. After 4 weeks of treatment， Morris water maze test was performed. Hematoxylineosin （HE） staining was used to observe the pathological changes of rat hippocampus. Sampling blood from abdominal aorta was taken. Acetylcholine （ACh）， acetylcholinesterase （AchE） and choline acetyltransferase （ChAT） in serum and hippocampus were detected by enzyme-linked immunosorbent assay （ELISA）. The expression of hippocampal <italic>α</italic>7 nicotinic acetylcholine receptor （<italic>α</italic>7nAChR） protein was detected by Western blot. The expression of hippocampal <italic>α</italic>7nAChR mRNA was detected by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. Result:Compared with the normal group， there were obvious pathological changes in the model group，such as neuron necrosis in the cerebral cortex，pyramidal cell or granular cell necrosis in the hippocampus，disorder of arrangement and inflammatory cell infiltration，prolonged escape latency，decreased escape platform times，decreased residence time in the effective area and swimming path in the effective area （<italic>P<</italic>0.05，<italic>P<</italic>0.01）. The contents of <italic>α</italic>7nAChR mRNA，ACh，AchE，ChAT，<italic>α</italic>7nAChR in the hippocampus decreased （<italic>P<</italic>0.01）. Compared with the model group，the escape latency of the middle dose group was shorter （<italic>P<</italic>0.05）， the escape platform times，the swimming path in the effective area and the residence time in the effective area increased （<italic>P<</italic>0.05，<italic>P<</italic>0.01）， the contents of serum ACh，ChAT， hippocampal AchE，ChAT and <italic>α</italic>7nAChR increased （<italic>P<</italic>0.05，）. The expression of hippocampal <italic>α</italic>7nAChR protein significantly increased （<italic>P<</italic>0.01）， the residence time of effective area in high dose group was prolonged （<italic>P<</italic>0.01）， the times of escape platform increased，and the contents of serum ACh，ChAT and hippocampal ACh，AchE，<italic>α</italic>7nAChR protein and <italic>α</italic>7nAChR mRNA increased （<italic>P<</italic>0.05）. Conclusion:Huanglian Jiedutang can significantly improve the learning and memory ability of AD rats induced by A<italic>β</italic>_1-42，and its mechanism may be related to the improvement of cholinergic system damage and enhancement of cholinergic system function induced by A<italic>β</italic>_1-42.

Preliminary study on the efficacy of ultrasound therapy in the rat model of sepsis / 中华危重病急救医学

Objective:To investigate the possible mechanism of ultrasound therapy in the rat model of sepsis.Methods:Seventy-eight male Sprague-Dawley (SD) rats were randomly divided into Sham group ( n = 12), septic model group ( n = 22), ultrasound treatment group ( n = 22), methyllycaconitine citrate (MLA) combined with ultrasound treatment group ( n = 22). In the Sham group, only the abdomen was opened, the cecum was found to be free, without cecal ligation and puncture (CLP). In the septic model group, CLP was used to replicate the septic rat model. After operation, each group of rats were subcutaneously injected with preheated 37 ℃ normal saline. The rats in the ultrasound treatment group were treated with ultrasound [Philips IU22 L9-3 ultrasound instrument and 9 MHz probe were used to break the sequence in the spleen area once every 6 seconds, with 1 second for each time, the mechanical index (MI) was 0.72, and the treatment time was 10 minutes]. In the MLA combined with ultrasound treatment group, α7 nicotinic acetylcholine receptor (α7nAChR) specific blocker MLA 4 mg/kg was injected intraperitoneally 30 minutes before operation, and ultrasound treatment was performed 2 hours after operation. The levels of tumor necrosis factor-α (TNF-α) and interleukin (IL-1β, IL-6) in serum of each group were measured by enzyme-linked immunosorbent assay (ELISA) at 24 hours after operation. The 10-day survival rate of each group was recorded, and the symptoms of each group were evaluated by clinical disease score (CDS). The histopathological changes of lung and colon were observed under light microscope. Results:Compared with the Sham group, the 10-day survival rate of rats in the septic model group was decreased significantly [40% (4/10) vs. 100% (6/6)], the CDS was (10.73±2.19 vs. 6.17±0.58) and the levels of TNF-α, IL-6, and IL-1β were increased significantly at 24 hours after operation [TNF-α (ng/L): 42.00±8.92 vs. 13.16±3.19, IL-6 (ng/L): 129.37±25.04 vs. 63.99±12.92, IL-1β(ng/L): 254.98±67.27 vs. 76.83±25.39, all P < 0.01]. Compared with the septic model group, the survival rate in the ultrasound treatment group was improved [70% (7/10) vs. 40% (4/10)], but there was no significant difference ( P > 0.05). The CDS (7.64±2.68 vs. 10.73±2.19) and the expressions of TNF-α, IL-6, and IL-1β were significantly reduced at 24 hours after operation [TNF-α(ng/L): 16.93±6.02 vs. 42.00±8.92, IL-6 (ng/L): 73.65±24.38 vs. 129.37±25.04, IL-1β(ng/L): 111.86±14.08 vs. 254.98±67.27, all P < 0.01]. Compared with the ultrasound treatment group, the survival rate in the MLA combined with ultrasound treatment group was reduced [60% (6/10) vs. 70% (7/10)], but the difference was not statistically significant ( P > 0.05). CDS was significantly increased (9.55±2.72 vs. 7.64±2.68), and the levels of TNF-α, IL-6 and IL-1β were significantly increased at 24 hours after operation [TNF-α(ng/L): 34.61±7.89 vs. 16.93±6.02, IL-6 (ng/L): 112.92±10.42 vs. 73.65±24.38, IL-1β(ng/L): 212.57±32.16 vs. 111.86±14.08, all P < 0.01]. Microscopically, in the septic model group, the alveolar septum was thickened, a large number of inflammatory cells infiltrated, normal pulmonary reticular structure disappeared, and pulmonary interstitium showed obvious hemorrhage and edema, meanwhile, the structure of colonic villi was obviously abnormal, with cells were edema and inflammatory cell infiltration, and the arrangement was disordered, so that the subepithelial space and the top of it fell off. After ultrasound treatment, the thickness of the alveolar interval in rats was similar to that in Sham group, without obvious inflammatory cell infiltration, and the pulmonary reticular structure was relatively intact. At the same time, the morphology of colonic villi was basically normal and orderly, the edema of cell was not obvious, and subcutaneous space and tip fall off were not obvious. After being antagonized by MLA, the rat lung tissue showed thickened alveolar septum, inflammatory cell infiltration, incomplete pulmonary network structure, hemorrhage and edema in the interstitium. The villi structure of the colon was faintly visible, with obvious cell edema and inflammatory cell infiltration, and the arrangement was abnormal. Conclusion:Ultrasound treatment improves the prognosis of septic rats, MLA can reverse the anti-inflammatory effect of ultrasound therapy by antagonizing α7nAChR, suggesting that the protective mechanism of ultrasound in sepsis may be related to activating the cholinergic anti-inflammatory pathway mediated by α7nAChR.

Effects of electrical stimulation of vagus nerve on α7 nicotinic acetylcholine receptor and inflammatory factors in ischemic stroke model mice / 中华行为医学与脑科学杂志

Objective:To explore the effect of α7 nicotinic acetylcholine receptor (α7nAchR) and changes of inflammatory factors during vagus nerve electrical stimulation in ischemic stroke model mice.Methods:Ninety SPF grade mice were randomly divided into sham operation+ vagus nerve electrical stimulation group (sham+ VNS group), model group (permanent middle cerebral artery occlusion group, pMCAO group), model+ vagus nerve electrical stimulation (pMCAO+ VNS group) and model group+ α7nAchR agonist group (pMCAO+ P group), model + vagus nerve electrical stimulation+ α7nAchR antagonist (pMCAO+ VNS+ A group), model+ vagus nerve electrical stimulation+ α7nAchR antagonist placebo group (pMCAO+ VNS+ AC group), with 15 mice in each group. The changes of vital signs of mice in each group were monitored during modeling.At 7, 14 and 21 days after successful modeling, neurological severity score (NSS) and adhesive removal test were used to evaluate the neurological deficit of mice.Immunofluorescence and Western blot were used to detect the expression of α7nAchR and its neural cell localization. ELISA was used to detect the level of TNF-α and IL-6. Prism 8.0 software was used for statistical analysis, and one-way ANOVA was used to analyze the physiological parameters during modeling.Repeated measurement ANOVA was used to compare the neurobehavioral score results, and t-test was used to compare the protein level and fluorescence intensity. Results:(1)The results of repeated measurement ANOVA showed that the interaction between group and time in NSS score was not significant ( F=0.91, P>0.05), and the group main effect ( F=46.68, P<0.05) and time main effect ( F=25.56, P<0.05) were significant. The results of Tukey's test showed that the NSS scores of pMCAO+ VNS group and pMCAO+ P group were significantly lower than those of pMCAO group (both P<0.05). There was no significant difference between pMCAO+ P group and pMCAO+ VNS group ( P>0.05). The NSS scores in pMCAO+ VNS+ A group were higher than that in pMCAO+ VNS group ( P<0.05), and significantly lower than that in pMCAO+ VNS+ AC group ( P<0.05). In the adhesive removal test, the interaction between group and time in the adhesive tape contact time and tear off time of mice was not significant ( F=0.67, 0.71, all P>0.05), and the group main effect ( F=30.12, 42.46, all P<0.05) and time main effect ( F=52.18, 47.34, all P<0.05) of mice in each group were significant.Tukey's test showed that the adhesive removal test on the 21st day, the adhesive tape contact time and tear off time of pMCAO+ VNS group were significantly shorter than those of pMCAO group (both P<0.05), and there was no significant difference between pMCAO+ P group and pMCAO+ VNS group (both P>0.05). (2)Western blot showed that compared with pMCAO group (0.36±0.01), the expression of α7nAchR in pMCAO+ VNS group (0.83±0.03) and pMCAO+ P group (0.67±0.02) increased ( t=13.53, 16.08, both P<0.01). The expression of α7nAchR in PCAO+ VNS+ A group (0.37±0.01) was significantly lower than that in PCAO+ VNS group ( t=12.88, P<0.01). Immunofluorescence results also showed that compared with pMCAO group (3.75±0.19), the expression of α7nAchR in pMCAO+ VNS group (8.96±0.48) and pMCAO+ P group increased (8.17±0.64) ( t=10.04, 6.67, both P<0.05). Immunofluorescence results also showed that compared with the pMCAO group (3.75±0.19), the expression of α7nAchR protein in the brain tissue of mice in the pMCAO+ VNS group and pMCAO+ P group increased ((8.96±0.48), (8.17±0.64), t=10.04, 6.67, all P<0.05). (3)The results of ELISA showed that compared with pMCAO group, the levels of TNF-a and IL-6 in serum and tissue supernatant of pMCAO+ VNS group and pMCAO+ P group were significantly lower than those of pMCAO group ( t=23.28, 15.30, 12.26, 11.08; all P<0.05). TNF in serum and tissue supernatant of mice in pMCAO+ VNS+ A group The levels of IL-6 in serum and tissue supernatant were significantly higher than those in pMCAO+ VNS group ( t=12.70, 11.01, 11.69, 17.37; all P<0.05) and pMCAO+ VNS+ AC group ( t=12.29, 11.07, 14.61, 29.27; all P<0.05). Conclusion:VNS may reduce inflammation by increasing the expression of α7nAchR protein in brain tissue, thereby playing a certain neuroprotective effect on ischemic stroke.

The anti-inflammatory role of α7 nicotinic acetylcholine receptor in microglial cells and its mechanisms / 药学实践杂志

Objective To investigate the anti-inflammatory role of α7 nicotinic acetylcholine receptor (α7nAChR) under inflammatory stress and its mechanisms. Methods PNU282987 was used for the activation of α7nAChR and LPS was administrated as inflammatory stressor. Realtime PCR was used for the detection of IL-1β, IL-6, TNF-α, M1 macrophage marker CD68, CD86 and M2 macrophage marker CD206, Arg1. Cell immunofluorescence was used for the detection of M1/M2 ratio and Western blot was applied for the detection of autophagy-related proteins. Results Under the stimulation of LPS, the mRNA levels of proinflammatory cytokines IL-1β, IL-6 and TNF-α, the proportion of M1 macrophage and autophagy process were increased in BV2 microglial cells. However, the administration of PNU282987 significantly decreased the mRNA levels of IL-1β, IL-6 and TNF-α and the proportion of M1 macrophage while increased the proportion of M2 macrophage and the level of autophagy process. Conclusion Activating α7nAChR plays an anti-inflammatory role in microglial cells under inflammatory stress due to the regulation of M1/M2 macrophage ratio and increase of autophagy level.

Design, synthesis, and activity study of α-conotoxin A10LPnIA fluorescent probe / 药学学报

italic>α7 nicotinic acetylcholine receptor (nAChR) is widely distributed in the central and peripheral nervous systems, and is closely related to a variety of neurological diseases and inflammation response. α-Conotoxin [A10L]PnIA, as an antagonist targeting α7 nAChR, plays an important role in studying the physiological and pathological processes involved in α7 nAChR. [A10L]PnIA was labeled with fluorescein 5-carboxytetramethylrhodamine, and the active peptide ([A10L]PnIA-F) was obtained by a two-step oxidative folding procedure in vitro. The Xenopus oocyte expression system and the two-electrode voltage clamp technique were used to identify the potency of [A10L]PnIA-F fluorescent peptide, and its cytotoxicity was detected by mouse macrophages and CCK8 method. The molecular weight of [A10L]PnIA-F fluorescent peptide was identified by mass spectrometry as 2 077.28 Da, which was consistent with the theoretical value. Electrophysiological determination of its half-maximal inhibitory concentration (IC50) for α7 nAChR is 17.32 nmol·L-1, which is consistent with [A10L]PnIA (IC50, 13.84 nmol·L-1). The cytotoxicity test results showed that within the concentration range of 5 nmol·L-1 to 10 μmol·L-1, there was no significant inhibition on the growth of mouse macrophages. The results showed that the α-conotoxin fluorescent probe [A10L]PnIA could provide pharmacological tools for the research of α7 nAChR-related neurophysiological and pathological mechanisms.

Effect of vagus nerve stimulation on α7 nicotinic acetylcholine receptor and inflammatory factor expressions and behavioristics in rats after traumatic brain injury / 中华神经医学杂志

Objective:To investigate the effect of vagus nerve stimulation (VNS) on α7 nicotinic acetylcholine receptor (α7 nAChR) and inflammatory factor expressions and behavioristics in rats after traumatic brain injury (TBI).Methods:Seventy-two male Sprague-Dawley rats were randomly divided into sham-operated group, TBI group and VNS group ( n=24). The TBI models in the latter two groups were established by modified weight drop method; the dura mater in the sham-operated group was exposed without impingement. The VNS group received VNS treatment for 14 consecutive d (frequency: 30 Hz, pulse width: 100 μs, current: 0.8 mA, stimulation: 5 min, suspension: 5 min, repetition: 3 times). The neurological function was evaluated by Beam-Balance test and walking test 1, 3, 7, 14, 21, and 28 d after TBI; Morris Water Maze test was performed to observe the abilities of spatial learning and memory 24-28 d after TBI; the brain tissue sections were obtained for analyzing the volume of cerebral injury 28 d after TBI. Fourteen d after TBI, Nissel staining was used to observe the neuronal morphology and survival cell number of brain injured areas in each group, immunohistochemical staining was employed to detect the number of neuronalnuclear antigen (NeuN) positive neurons in the hippocampal dentate gyrus and CA3 area, and ELISA was used to detect the expressions of interleukin (IL)-1, IL-6, tumor necrosis factor (TNF)-α and nuclear factor (NF)-κB. Western blotting was used to detect the α7 nAChR protein expression levels 3, 7, 14 d after TBI. Results:As compared with the TBI group, the VNS group showed statistically longer beam-balance latency and shorter beam-walking time 7, 14, 21, and 28 d after TBI, significantly shortened escape latency and prolonged exploration time in the target quadrant 27 and 28 d after TBI ( P<0.05). The volume of cerebral injury in the VNS group was significantly smaller than that in TBI group 28 d after TBI ( P<0.05). As compared with those in the TBI group, the number of Nissel positive neurons around the brain injury area was significantly larger, the number of NeuN positive cells in the hippocampal dentate gyrus and CA3 areas was significantly larger, and the expression levels of IL-1β, IL-6, TNF-α and NF-κB were significantly decreased in the VNS group 14 d after TBI ( P<0.05). The α7 nAChR protein expression in the injury area of VNS group was significantly higher than that of the TBI group 7 and 14 d after TBI ( P<0.05). Conclusion:VNS treatment can improve the neurobehavioral outcome of TBI rats, which may be linked with the increased α7 nAChR protein expression, and the decreased release of inflammation cytokines IL-1β, IL-6, TNF-α and NF-κB.

Establishment of a gp120 transgenic mouse model with 7 nAChR knockout / 南方医科大学学报

OBJECTIVE@#To construct a HIV-1 gp120 transgenic mouse model (gp120) with 7 nicotinic acetylcholine receptor (7nAChR) gene knockout.@*METHODS@#The 7nAChR gene knockout mice (7R) were crossed with HIV-1gp120 transgenic mice (gp120) to generate F1 generation mice. We selected the F1 mice with the genotype of 7R/gp120 to mate to obtain the F2 mice. The genotypes of the F3 mice were identified by PCR, and the protein expressions in the double transgenic animal model was analyzed by immunohistochemistry. BV2 cells were treated with gp120 protein and 7nAChR inhibitor, and the expressions of IL-1β and TNF- were detected using ELISA.@*RESULTS@#The results of PCR showed the bands of the expected size in F3 mice. Two F3 mice with successful double gene editing (7R/gp120) were obtained, and immunohistochemistry showed that the brain tissue of the mice did not express 7 nAChR but with high gp120 protein expression. In the cell experiment, treatment with gp120 promoted the secretion of IL-1β and TNF- in BV2 cells, while inhibition of 7nAChR significantly decreased the expression of IL-1β and TNF- ( < 0.001).@*CONCLUSIONS@#By mating gp120 Tg mice with 7R mice, we obtained gp120 transgenic mice with 7nAChR gene deletion, which serve as a new animal model for exploring the role of 7nAChR in gp120-induced neurotoxicity.

Fecal microbiota transplantation regulates the cholinergic anti-inflammatory pathway in cerebral cortex of septic rats through intestinal microbiota / 中华危重病急救医学

Objective To investigate the effects of fecal microbiota transplantation on septic gut flora and the cortex cholinergic anti-inflammatory pathway in rats. Methods Sixty clean grade male Sprague-Dawley (SD) rats were divided into normal saline (NS) control group, sepsis model group and fecal microbiota transplantation group by random number table, with 20 rats in each group. The rat model of sepsis was reproduced by injection of 10 mg/kg lipopolysaccharide (LPS) via tail vein, the rats in the NS control group was given the same amount of NS. The rats in the fecal microbiota transplantation group received nasogastric infusion of feces from healthy donor on the 1st day, 2 mL each time, for 3 times a day, the other two groups were given equal dose of NS by gavage. Fecal samples were collected on the 7th day after modeling, the levels of intestinal microbiota composition was determined using the 16SrDNA gene sequencing technology. The brain function was evaluated by electroencephalogram (EEG), and the proportion of each waveform in EEG was calculated. After sacrifice of rats, the brain tissues were harvested, the levels of protein expression of α7 nicotinic acetylcholine receptor (α7nAChR) were determined by Western Blot, and positive cells of Iba-1 in brain tissue were detected by immunohistochemistry method. The levels of interleukins (IL-6 and IL-1β) and tumor necrosis factor-α (TNF-α) were determined by enzyme-linked immunosorbent assay (ELISA). Results Seven days after the reproduction of the model, all rats in the NS control group survived, while 10 rats and 8 rats died in the sepsis model group and fecal microbiota transplantation group, respectively, with mortality rates of 50% and 40% respectively. Finally, there were 20 rats in the NS control group, 10 in the sepsis model group and 12 in the fecal microbiota transplantation group. Compared with the NS control group, the diversity and composition of intestinal flora were changed, the incidence of abnormal EEG increased significantly, the expression of α7nAchR in the cortex decreased significantly, and the levels of Iba-1, TNF-α, IL-6 and IL-1β were significantly increased in the model group, suggested that the intestinal flora was dysbiosis, and severe inflammatory reaction occurred in the cerebral cortex, and brain function was impaired. Compared with the model group, the diversity of intestinal flora in the fecal microbiota transplantation group was significantly increased (species index: 510.24±58.76 vs. 282.50±47.42, Chao1 index: 852.75±25.24 vs. 705.50±46.50, both P < 0.05), the dysbiosis of intestinal flora at phylum, family, genus level induced by LPS were also significantly reversed, and with the improvement of intestinal flora, the incidence of abnormal EEG waveforms was lower in the fecal microbiota transplantation group compared with that in the model group [25.0% (3/12) vs. 80.0% (8/10), P < 0.05], and the expression of α7nAChR protein in the cerebral cortex was significantly increased (α7nAChR/β-actin: 1.56±0.05 vs. 0.82±0.07, P < 0.05), immunohistochemistry analysis showed that Iba-1 positive expression of microglia decreased significantly, and cerebral cortex TNF-α, IL-6, IL-1β levels were significantly decreased [TNF-α (ng/L): 6.28±0.61 vs. 12.02±0.54, IL-6 (ng/L): 28.26±3.15 vs. 60.58±4.62, IL-1β (ng/L): 33.63±3.48 vs. 72.56±2.25, all P < 0.05]. Conclusion The results reveal that fecal microbiota transplantation has remarkably modulated the dysbiosis of intestinal microbiota and activated cholinergic anti-inflammatory pathway, and ameliorate the brain dysfunction in septic rats.

Fecal microbiota transplantation regulates the cholinergic anti-inflammatory pathway in cerebral cortex of septic rats through intestinal microbiota / 中华危重病急救医学

Objective@#To investigate the effects of fecal microbiota transplantation on septic gut flora and the cortex cholinergic anti-inflammatory pathway in rats.@*Methods@#Sixty clean grade male Sprague-Dawley (SD) rats were divided into normal saline (NS) control group, sepsis model group and fecal microbiota transplantation group by random number table, with 20 rats in each group. The rat model of sepsis was reproduced by injection of 10 mg/kg lipopolysaccharide (LPS) via tail vein, the rats in the NS control group was given the same amount of NS. The rats in the fecal microbiota transplantation group received nasogastric infusion of feces from healthy donor on the 1st day, 2 mL each time, for 3 times a day, the other two groups were given equal dose of NS by gavage. Fecal samples were collected on the 7th day after modeling, the levels of intestinal microbiota composition was determined using the 16SrDNA gene sequencing technology. The brain function was evaluated by electroencephalogram (EEG), and the proportion of each waveform in EEG was calculated. After sacrifice of rats, the brain tissues were harvested, the levels of protein expression of α7 nicotinic acetylcholine receptor (α7nAChR) were determined by Western Blot, and positive cells of Iba-1 in brain tissue were detected by immunohistochemistry method. The levels of interleukins (IL-6 and IL-1β) and tumor necrosis factor-α (TNF-α) were determined by enzyme-linked immunosorbent assay (ELISA).@*Results@#Seven days after the reproduction of the model, all rats in the NS control group survived, while 10 rats and 8 rats died in the sepsis model group and fecal microbiota transplantation group, respectively, with mortality rates of 50% and 40% respectively. Finally, there were 20 rats in the NS control group, 10 in the sepsis model group and 12 in the fecal microbiota transplantation group. Compared with the NS control group, the diversity and composition of intestinal flora were changed, the incidence of abnormal EEG increased significantly, the expression of α7nAchR in the cortex decreased significantly, and the levels of Iba-1, TNF-α, IL-6 and IL-1β were significantly increased in the model group, suggested that the intestinal flora was dysbiosis, and severe inflammatory reaction occurred in the cerebral cortex, and brain function was impaired. Compared with the model group, the diversity of intestinal flora in the fecal microbiota transplantation group was significantly increased (species index: 510.24±58.76 vs. 282.50±47.42, Chao1 index: 852.75±25.24 vs. 705.50±46.50, both P < 0.05), the dysbiosis of intestinal flora at phylum, family, genus level induced by LPS were also significantly reversed, and with the improvement of intestinal flora, the incidence of abnormal EEG waveforms was lower in the fecal microbiota transplantation group compared with that in the model group [25.0% (3/12) vs. 80.0% (8/10), P < 0.05], and the expression of α7nAChR protein in the cerebral cortex was significantly increased (α7nAChR/β-actin: 1.56±0.05 vs. 0.82±0.07, P < 0.05), immunohistochemistry analysis showed that Iba-1 positive expression of microglia decreased significantly, and cerebral cortex TNF-α, IL-6, IL-1β levels were significantly decreased [TNF-α (ng/L): 6.28±0.61 vs. 12.02±0.54, IL-6 (ng/L): 28.26±3.15 vs. 60.58±4.62, IL-1β (ng/L): 33.63±3.48 vs. 72.56±2.25, all P < 0.05].@*Conclusion@#The results reveal that fecal microbiota transplantation has remarkably modulated the dysbiosis of intestinal microbiota and activated cholinergic anti-inflammatory pathway, and ameliorate the brain dysfunction in septic rats.

Effects of sevoflurane anesthesia on the quantity of alpha 7 nicotinic acetylcholine receptor, cholinesterase, and choline acetyl translocase in the rat hippocampus / 临床麻醉学杂志

Objective To investigate the expression of alpha 7 nicotinic acetylcholine receptor (α7 nAchR), cholinesterase (AChE), choline acetyl translocase (ChaT) after sevoflurane anesthesia. Methods A total of 120 healthy Sprague-Dawley rats with both two genders, aged 1 week, were randomly divided into 5 groups: blank group; air/O2 group; sevoflurane group (group SEV); α7 nAchR agonist group (group PUN); α7 nAchR antagonist group (group MLA), 24 in each group. Blank group received free feeding, air/O2 group was inhaled 60％ oxygen (carrier gas: 1 L/min O2+1 L/min air) 2 h; group SEV was inhaled 3.4％ sevoflurane and carrier gas for 2 h; group PUN and group MLA were injected with PNU-282987 and methyllycaconitine, respectively, after 24 h inhaled of 3.4％ sevoflurane and carrier gas for 2 h. After that, hippocampus dissection carried out in 2 h, 1 w, 4 w, and Western blot method was used to detect α7 nAchR, AChE, ChaT proteins expression. Results Two hours after anesthesia recovery, α7 nAchR in groups SEV, PNU and MLA was significantly lower than that in air/O2 group (P ＜ 0.05); AChE in groups PNU and MLA was significantly lower than that in air/O2 group (P ＜ 0.05); ChaT in groups SEV, PNU and MLA was significantly lower than that in air/O2 group (P ＜ 0.05). One week after anesthesia recovery, α7 nAchR in blank group and groups SEV and PNU was significantly higher than that in air/O2 group (P ＜ 0.05), α7 nAchR in group MLA was significantly lower than that in air/O2 group (P ＜ 0.05); AChE in blank group and and group PNU was significantly higher than that in air/O2 group (P ＜ 0.05), ChaT in blank group was significantly higher than that in air/O2 group (P ＜ 0.05), ChaT in group SEV was significantly lower than that in air/O2 group (P ＜ 0.05). Four weeks after anesthesia awake, AChE in each group was not statistically significant; α7 nAchR in group SEV was significantly higher than that in blank group (P ＜ 0.05), α7 nAchR in group PNU and MLA was significantly lower than that in blank group (P ＜ 0.05); ChaT in blank group and group PNU was significantly lower than that in air/O2 group (P ＜ 0.05), ChaT in group MLA was significantly higher than that in air/O2 group (P ＜ 0.05). Conclusion Sevoflurane inhalation can inhibit ChaT, α7 nAChR, which had no direct effect on AChE; α7 nAChR agonist can effectively help α7 nAChR and ChaT inhibition inhaled sevoflurane, and reached a peak at about 1 week; oxygen concentration around 60％ can increase α7 nAChR expression quantity, to a certain extent against sevoflurane inhibition.

Neuroprotective effect of the ethanol extract of Artemisia capillaris on transient forebrain ischemia in mice via nicotinic cholinergic receptor / 中国天然药物

Artemisia capillaris Thunberg is a medicinal plant used as a traditional medicine in many cultures. It is an effective remedy for liver problems including hepatitis. Recent pharmacological reports have indicated that Artemisia species can exert various neurological effects. Previously, we reported a memory-enhancing effect of Artemisia species. However, the mechanisms underlying the neuroprotective effect of A. capillaris (AC) are still unknown. In the present study, we investigated the effect of an ethanol extract of AC on ischemic brain injury in a mouse model of transient forebrain ischemia. The mice were treated with AC for seven days, beginning one day before induction of transient forebrain ischemia. Behavioral deficits were investigated using the Y-maze. Nissl and Fluoro-jade B staining were used to indicate the site of injury. To determine the underlying mechanisms for the drug, we measured acetylcholinesterase activity. AC (200 mg·kg) treatment reduced transient forebrain ischemia-induced neuronal cell death in the hippocampal CA1 region. The AC-treated group also showed significant amelioration in the spontaneous alternation of the Y-maze test performance, compared to that in the untreated transient forebrain ischemia group. Moreover, AC treatment showed a concentration-dependent inhibitory effect on acetylcholinesterase activity in vitro. Finally, the effect of AC on forebrain ischemia was blocked by mecamylamine, a nonselective nicotinic acetylcholine receptor antagonist. Our results suggested that in a model of forebrain ischemia, AC protected against neuronal death through the activation of nicotinic acetylcholine receptors.