Echinacoside Alleviates Cognitive Impairment in Cerebral Ischemia Rats through α 7nAChR-Induced Autophagy / 中国结合医学杂志

OBJECTIVES@#To evaluate the effect of echinacoside (ECH) on cognitive dysfunction in post cerebral stroke model rats.@*METHODS@#The post stroke cognitive impairment rat model was created by occlusion of the transient middle cerebral artery (MCAO). The rats were randomly divided into 3 groups by a random number table: the sham group (sham operation), the MCAO group (received operation for focal cerebral ischemia), and the ECH group (received operation for focal cerebral ischemia and ECH 50 mg/kg per day), with 6 rats in each group. The infarct volume and spatial learning were evaluated by triphenyl tetrazolium chloride staining and Morris water maze. The expression of α7nAChR in the hippocampus was detected by immunohistochemistry. The contents of acetylcholine (ACh), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), activities of choline acetyltransferase (ChAT), acetylcholinesterase (AChE), and catalase (CAT) were evaluated by enzyme linked immunosorbent assay. The neural apoptosis and autophagy were determined by TUNEL staining and LC3 staining, respectively.@*RESULTS@#ECH significantly lessened the brain infarct volume and ameliorated neurological deficit in infarct volume and water content (both P<0.01). Compared with MCAO rats, administration of ECH revealed shorter escape latency and long retention time at 7, 14 and 28 days (all P<0.01), increased the α7nAChR protein expression, ACh content, and ChAT activity, and decreased AChE activity in MCAO rats (all P<0.01). ECH significantly decreased MDA content and increased the GSH content, SOD, and CAT activities compared with MCAO rats (all P<0.05). ECH suppressed neuronal apoptosis by reducing TUNEL-positive cells and also enhanced autophagy in MCAO rats (all P<0.01).@*CONCLUSION@#ECH treatment helped improve cognitive impairment by attenuating neurological damage and enhancing autophagy in MCAO rats.

Enriched environment alleviates post-stroke cognitive impairment through enhancing α7-nAChR expression in rats / Ambiente enriquecido alivia o comprometimento cognitivo pós-AVC em ratos por meio do aumento da expressão de α7-nAChR

ABSTRACT Background: Enriched environment (EE) is a simple and effective intervention to improve cognitive function in post-stroke cognitive impairment (PSCI), partly due to the rebalancing of the cholinergic signaling pathway in the hippocampus. α7-nicotinic acetylcholine receptor (α7-nAChR) is a cholinergic receptor whose activation inhibits inflammation and promotes the recovery of neurological function in PSCI patients. However, it is still unclear whether EE can regulate α7-nAChR and activate the cholinergic anti-inflammatory pathway (CAP) in PSCI. Objective: To investigate the effects of EE on cognitive impairment, and the role of α7-nAChR in PSCI. Methods: A PSCI rat model was induced by middle cerebral artery occlusion and reperfusion (MCAO/R) and were reared in standard environment (SE) or EE for 28d, control group with sham surgery. Cognitive function was determined by Morris water maze test. The long-term potentiation (LTP) was assessed by Electrophysiology. Histopathological methods were used to determine infarct volume, α7-nAChR expression and the cytokines and cholinergic proteins expression. Results: Compared with SE group, rats in EE group had better cognitive function, higher expression of α7-nAChR positive neurons in hippocampal CA1 region. In addition, EE attenuated unfavorable changes induced by MCAO/R in cytokines and cholinergic proteins, and also enhanced LTP promoted by nicotine and attenuated by α-BGT; but showed no significantly difference in infarct volume. Conclusions: EE markedly improves cognitive impairment and enhances neuroplasticity in PSCI rats, which may be closely related to enhancement of α7-nAChR expression.

RESUMO Introdução: O ambiente enriquecido (AE) é uma intervenção simples e eficaz para melhorar a função cognitiva no comprometimento cognitivo pós-AVC, em parte devido ao reequilíbrio da via de sinalização colinérgica no hipocampo. O receptor nicotínico α7 de acetilcolina (α7-nAChR) é um receptor colinérgico cuja ativação inibe inflamação e promove a recuperação da função neurológica em pacientes com comprometimento cognitivo pós-AVC. No entanto, ainda não está claro se o AE pode regular α7-nAChR e ativar a via anti-inflamatória colinérgica (VAC) em comprometimento cognitivo pós-AVC. Objetivo: Investigar os efeitos do AE no comprometimento cognitivo e o papel do α7-nAChR no comprometimento cognitivo pós-AVC. Métodos: Modelo de comprometimento cognitivo pós-AVC foi induzido em ratos por oclusão e reperfusão da artéria cerebral média (MCAO/R), que foram criados em ambiente padrão (AP) ou em AE por 28d; grupo controle com cirurgia simulada. A função cognitiva foi determinada pelo teste do labirinto aquático de Morris. A potenciação de longo prazo (PLP) foi avaliada por eletrofisiologia. Métodos histopatológicos foram usados para determinar o volume do infarto, a expressão de α7-nAChR e a expressão de citocinas e proteínas colinérgicas. Resultados: Em comparação com o grupo AP, os ratos do grupo AE tiveram melhor função cognitiva, com maior expressão de neurônios positivos para α7-nAChR na região CA1 do hipocampo. Além disso, o AE atenuou alterações desfavoráveis induzidas por MCAO/R em citocinas e proteínas colinérgicas, e também aumentou a PLP promovida pela nicotina e atenuada por α-BGT, mas não mostrou nenhuma diferença significativa no volume do infarto. Conclusão: O AE melhora acentuadamente o comprometimento cognitivo e aumenta a neuroplasticidade em ratos com comprometimento cognitivo pós-AVC, o que pode estar intimamente relacionado ao aumento da expressão de α7-nAChR.

Cholinergic anti-inflammatory pathway and its role in treatment of sepsis / 中南大学学报(医学版)

The cholinergic anti-inflammatory pathway (CAP) is a neuro-immunomodulatory pathway,in which acetylcholine (ACh) released by the interaction of vagal nerves with α7 nicotinic acetylcholine receptor (α7nAChR),which prevents the synthesis and release of pro-inflammatory cytokines and ultimately regulates the local or systemic inflammatory response in a feedback manner. It has been shown that there are many possible effective treatments for sepsis, including vagus nerve stimulation by physical therapy, drugs such as acetylcholine receptor agonist and ultrasound therapy.

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.

Research advances of autonomic nervous system in the regulation of cardiac inflammation / 生理学报

The autonomic nervous system consists of the sympathetic nervous system and the parasympathetic nervous system. These two systems control the heart and work in a reciprocal fashion to modulate myocardial energy metabolism, heart rate as well as blood pressure. Multiple cardiac pathological conditions are accompanied by autonomic imbalance, characterized by sympathetic overactivation and parasympathetic inhibition. Studies have shown that overactive sympathetic nervous system leads to increased cardiac inflammatory reaction. Orchestrated inflammatory response serves to clear dead cardiac tissue and activate reparative process, whereas excessive inflammation may result in pathological cardiac remodeling. Since the discovery of the α7 nicotinic acetylcholine receptor (α7nAChR)-mediated cholinergic anti-inflammatory pathway (CAP), the protective effects of the parasympathetic nervous system in cardiac inflammation have attracted more attention recently. In this review, we summarized the role and underlying mechanisms of the sympathetic and parasympathetic nervous systems in cardiac inflammation, in order to provide new insight into cardiac inflammatory response in cardiovascular diseases.

Electrophysiological phenotypes of synaptic transmission and neural network in hippocampal neurons of the α7-nAChR knockout mice / 生理学报

It was reported that α7 nicotinic acetylcholine receptor (α7-nAChR) knockout (α7 KO) mice showed few functional phenotypes. The purpose of this study was to investigate the effect of α7 KO on the electrophysiological characteristics of hippocampus in mice. The effect of α7 KO on hippocampal CA3-CA1 synaptic transmission in mice was evaluated by standard extracellular field potential recordings. The electrophysiological phenotype of γ-aminobutyrate A receptors (GABA-Rs) of single hippocampal neuron was detected by perforated patch-clamp recordings. The results showed that, the slope of field excitatory postsynaptic potential (fEPSP) and carbachol-induced theta oscillation were significantly decreased in the hippocampal CA1 neurons of α7 KO mice, compared with those of wild type mice. Under the treatment of GABA-R agonist muscimol, the I-V curves of both the hippocampal CA1 and CA3 neurons of α7 KO mice shifted towards depolarizing direction obviously, compared with those of wild type mice. These results suggest that the hippocampal CA3-CA1 synaptic transmission in α7 KO mice was significantly impaired and GABA-R maturation was significantly delayed, indicating that the deletion of α7-nAChR gene could significantly change the electrophysiological function of the hippocampus. The results may provide a new understanding of the role of α7-nAChR in hippocampal function and associated diseases.

Effect of Shensong Yangxin on the Progression of Paroxysmal Atrial Fibrillation is Correlated with Regulation of Autonomic Nerve Activity / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Shensong Yangxin (SSYX), a traditional Chinese herbal medicine, has long been used clinically to treat arrhythmias in China. However, the mechanism of SSYX on atrial fibrillation (AF) is unknown. In this study, we tested the hypothesis that the effect of SSYX on the progression of paroxysmal AF is correlated with the regulation of autonomic nerve activity.</p><p><b>METHODS</b>Eighteen mongrel dogs were randomly divided into control group (n = 6), pacing group (n = 6), and pacing + SSYX group (n = 6). The control group was implanted with pacemakers without pacing; the pacing group was implanted with pacemakers with long-term intermittent atrial pacing; the pacing + SSYX group underwent long-term intermittent atrial pacing and SSYX oral administration.</p><p><b>RESULTS</b>Compared to the pacing group, the parameters of heart rate variability were lower after 8 weeks in the pacing + SSYX group (low-frequency [LF] component: 20.85 ± 3.14 vs. 15.3 ± 1.89 ms 2 , P = 0.004; LF component/high-frequency component: 1.34 ± 0.33 vs. 0.77 ± 0.15, P < 0.001). The atrial effective refractory period (AERP) was shorter and the dispersion of the AERP was higher after 8 weeks in the pacing group, while the changes were suppressed by SSYX intake. The dogs in the pacing group had more episodes and longer durations of AF than that in the pacing + SSYX group. SSYX markedly inhibited the increase in sympathetic nerves and upregulation of tumor necrosis factor-alpha and interleukin-6 expression in the pacing + SSYX group. Furthermore, SSYX suppressed the decrease of acetylcholine and α7 nicotinic acetylcholine receptor protein induced by long-term intermittent atrial pacing.</p><p><b>CONCLUSIONS</b>SSYX substantially prevents atrial electrical remodeling and the progression of AF. These effects of SSYX may have association with regulating the imbalance of autonomic nerve activity and the cholinergic anti-inflammatory pathway.</p>

Berberine relieves insulin resistance via the cholinergic anti-inflammatory pathway in HepG2 cells / 华中科技大学学报（医学）（英德文版）

Berberine (BBR) is an isoquinoline alkaloid extracted from Rhizoma coptidis and has been used for treating type 2 diabetes mellitus (T2DM) in China. The development of T2DM is often associated with insulin resistance and impaired glucose uptake in peripheral tissues. In this study, we examined whether BBR attenuated glucose uptake dysfunction through the cholinergic anti-inflammatory pathway in HepG2 cells. Cellular glucose uptake, quantified by the 2-[N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)-amino]-2-deoxy-D-glucose (2-NBDG), was inhibited by 21% after HepG2 cells were incubated with insulin (10(-6) mol/L) for 36 h. Meanwhile, the expression of alpha7 nicotinic acetylcholine receptor (α7nAChR) protein was reduced without the change of acetylcholinesterase (AChE) activity. The level of interleukin-6 (IL-6) in the culture supernatant, the ratio of phosphorylated I-kappa-B kinase-β (IKκβ) Ser181/IKKβ and the expression of nuclear factor-kappa B (NF-κB) p65 protein were also increased. However, the treatment with BBR enhanced the glucose uptake, increased the expression of α7nAChR protein and inhibited AChE activity. These changes were also accompanied with the decrease of the ratio of pIKKβ Ser181/IKKβ, NF-κB p65 expression and IL-6 level. Taken together, these results suggest that BBR could enhance glucose uptake, and relieve insulin resistance and inflammation in HepG2 cells. The mechanism may be related to the cholinergic anti-inflammatory pathway and the inhibition of AChE activity.

Temporal and spatial changes of α7nAChR and nNOS in cerebral cortex and hippocampus of Aβ-induced cognitive dysfunction rats / 生理学报

The present study was to explore the temporal and spatial distributions and variations of α7 nicotinic acetylcholine receptor (α7nAChR) and neuronal nitric oxide synthetase (nNOS) in cerebral cortex and hippocampus of Aβ-induced cognitive dysfunction rats. Sixty Sprague-Dawley (SD) rats were randomly divided into six groups. Three experimental groups were intracerebroventricularly (i.c.v.) injected with condensed-amyloid beta peptides 1-42 (Aβ, 2.5 µg/µL, 4 µL) and were observed on day 7 (7 d Aβ group), day 14 (14 d Aβ group) and day 21 (21 d Aβ group), respectively. Three control groups were i.c.v. injected with equivalent volume of normal saline and observed at the same time points as the experimental groups. The learning and memory abilities of rats were tested with Y-maze; the locations and protein expression levels of α7nAChR and nNOS in cerebral cortex and hippocampal CA1, CA3, DG regions were measured by immunohistochemistry and Western blot, respectively. The result showed that, compared with the control groups, the three experimental groups exhibited decreased learning and memory behavioral abilities, and down-regulated expressions of nNOS and α7nAChR in prefrontal cortex and hippocampal regions, especially in superficial layer of prefrontal cortex and hippocampal CA3 region. Comparisons among the three experimental groups showed that the inhibitory effects of Aβ on the abilities of learning and memory and the expressions of α7nAChR and nNOS in prefrontal cortex and hippocampus were time dependent. The results suggest that the coincident declines of α7nAChR and nNOS in prefrontal cortex and hippocampus may be the foundations of the cognitive dysfunction.

Role of Nicotinic Acetylcholine Receptor alpha3 and alpha7 Subunits in Detrusor Overactivity Induced by Partial Bladder Outlet Obstruction in Rats / 대한배뇨장애요실금학회지

PURPOSE: To investigate the role of alpha3 and alpha7 nicotinic acetylcholine receptor subunits (nAChRs) in the bladder, using a rat model with detrusor overactivity induced by partial bladder outlet obstruction (BOO). METHODS: Forty Sprague-Dawley rats were used: 10 were sham-operated (control group) and 30 were observed for 3 weeks after partial BOO. BOO-induced rats were further divided into 3 groups: Two groups of 10 rats each received intravesicular infusions with hexamethonium (HM group; n=10) or methyllycaconitine (MLC group; n=10), which are antagonists for alpha3 and alpha7 nAChRs, respectively. The remaining BOO-induced rats received only saline infusion (BOO group; n=10). Based on the contraction interval measurements using cystometrogram, the contraction pressure and nonvoiding bladder contractions were compared between the control and the three BOO-induced groups. Immunofluorescent staining and Western blotting were used to analyze alpha3 and alpha7 nAChRs levels. RESULTS: The contraction interval of the MLC group was higher than that of the BOO group (P<0.05). Nonvoiding bladder contraction almost disappeared in the HM and MLC groups. Contraction pressure increased in the BOO group (P<0.05) compared with the control group and decreased in the HM and MLC groups compared with the BOO group (P<0.05). Immunofluorescence staining showed that the alpha3 nAChR signals increased in the urothelium, and the alpha7 nAChR signals increased in the urothelium and detrusor muscle of the BOO group compared with the control group. Western blot analysis showed that both alpha3 and alpha7 nAChR levels increased in the BOO group (P<0.05). CONCLUSIONS: Alpha3 and alpha7 nAChRs are associated with detrusor overactivity induced by BOO. Furthermore, nAChR antagonists could help in clinically improving detrusor overactivity.

Changes of neuronal acetylcholine receptor alpha 7 of peritoneal macrophage in experimental acute pancreatitis treated by Chaiqin Chengqi Decoction () / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate effect of Chaiqin Chengqi Decoction (, CQCQD) on changes of neuronal acetylcholine receptor alpha 7 (nAChRα7) of peritoneal macrophages in acute pancreatitis (AP).</p><p><b>METHODS</b>Eighteen Kunming mice were equally randomized into the control group, AP group and CQCQD treatment group. AP was induced by two intraperitoneal injections of 4 g/kg L-arginine at 1 h apart, while control mice received saline injections. At 72 h after the first injection of L-arginine, mice in the treatment group were intragastrically administered 0.1 mL/10 g CQCQD every 2 h for 3 times, whilst mice in the other two groups received the same amount of saline feeding. Mice were sacrificed by cervical dislocation 2 h after the last feeding of either CQCQD or saline. Peritoneal macrophages were collected for determination of nAChRα7 mRNA and protein expression. Serum was collected for detection of interleukin-6 (IL-6), IL-10 and acetylcholine (ACh) levels, and pancreas was for histopathology analysis.</p><p><b>RESULTS</b>The CQCQD treatment significantly ameliorated the severity of AP as evidenced by reducing the pancreatic histopathology score (4.5±0.5 vs. 6.2±1.7, P<0.05) and the serum IL-6 levels (1228.3±419.2 pg/mL vs. 1589.6±337.3 pg/mL, P<0.05). The mRNA and protein expression of nAChRα7 of the peritoneal macrophages in the AP group were similar to the control group (P>0.05), but were significantly up-regulated after the CQCQD treatment (P<0.05). The serum ACh levels in the AP group were significantly lower than those in the control group (3.1±0.6 μg/mL vs 4.8±0.7 μg/mL P<0.05), but were significantly increased after the CQCQD treatment (5.6±1.5 μg/mL vs 3.1±0.6 μg/mL, P<0.05).</p><p><b>CONCLUSION</b>CQCQD is protective against L-arginine-induced AP through mechanisms involving nAChRα7 of peritoneal macrophages.</p>

The synergetic effects of nitric oxide and nicotinic acetylcholine receptor on learning and memory of rats / 生理学报

The aim of the present study is to explore the interaction of nitric oxide (NO) and nicotinic acetylcholine receptor (nAChR) on learning and memory of rats. Rats were intracerebroventricularly (i.c.v.) injected with L-arginine (L-Arg, the NO precursor) (L-Arg group) or choline chloride (CC, an agonist of α7nAChR) (CC group), and with combined injection of L-Arg and CC (L-Arg+CC group), and methyllycaconitine (MLA, α7nAChR antagonist) or N(ω)-nitro-L-arginine methylester (L-NAME, nitric oxide synthase inhibitor) i.c.v. injected first and followed by administration of L-Arg combined with CC (MLA+L-Arg+CC group or L-NAME+L-Arg+CC group), respectively, and normal saline was used as control (NS group). The learning and memory ability of rats was tested with Y-maze; the level of NO and the expressions of neuronal nitric oxide synthase (nNOS) or α7nAChR in hippocampus were measured by NO assay kit, immunohistochemistry or Western blot. The results showed that compared with L-Arg group or CC group, the rats' learning and memory behavioral ability in Y-maze was observably enhanced and the level of NO, the optical density of nNOS-like immunoreactivity (LI) or α7nAChR-LI in hippocampus were significantly increased in L-Arg+CC group; Compared with L-Arg+CC group, the ability of learning and memory and the level of NO as well as the expressions of nNOS-LI or α7nAChR-LI were obviously decreased in MLA+L-Arg+CC group or in L-NAME+L-Arg+CC group. In conclusion, i.c.v. administration of L-Arg combined with CC significantly improved the action of the L-Arg or CC on the content of NO and the nNOS or α7nAChR expressions in hippocampus along with the learning and memory behavior of rats; when nNOS or α7nAChR was interrupted in advance, the effects of L-Arg combined with CC were also suppressed. The results suggest that there are probably synergistic effects between NO and nAChR on learning and memory.

Effects of subchronic benzoapyrene exposure on hippocampal cholinergic system in rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the effects of subchronic benzo[a]pyrene (B[a]P) exposure on the neurobehavior and hippocampal acetylcholine (Ach) level, acetylcholinesterase (AChE) activity, and mRNA and protein expression of nicotinic acetylcholine receptor α7 subtype (nAChR α7) in rats, and to investigate the neurotoxic mechanism of B[a]P.</p><p><b>METHODS</b>Sixty healthy male SD rats were randomly divided into blank control group, solvent control group, and B [a]P exposure groups. Each rat in the exposure groups was intraperitoneally injected with B[a]P at 1.0, 2.5, or 6.25 mg/kg once every other day for 90 days. The learning and memory ability of the rats was examined by Morris water maze test and step-down test; the hippocampal Ach level was measured by alkaline hydroxylamine method; the AChE activity was measured by DNTB method; the mRNA and protein expression levels of hippocampal nAChR α7 were measured by quantitative PCR and Western blot.</p><p><b>RESULTS</b>The 2.5 and 6.25 mg/kg B[a]P exposure groups showed significantly lower learning and memory abilities than the blank control group and solvent control group (P < 0.05); also, the two groups had significantly lower hippocampal Ach levels than the blank control group, solvent control group, and 1.0 mg/kg B[a]P exposure group (P < 0.05). The 6.25 mg/kg B[a]P exposure group showed significantly lower hippocampal AChE activity than the blank control group, solvent control group, and 1.0 mg/kg B[a]P exposure group (P < 0.05). There were no significant differences in the mRNA and protein expression levels of nAChR α7 among all groups (P > 0.05). The hippocampal Ach level was negatively correlated with the mean escape latency period and total distance travelled (r = -0.567, P < 0.01; r = -0.503, P < 0.01) but positively correlated with the time in platform quadrant (r = 0.800, P < 0.01).</p><p><b>CONCLUSION</b>Subchronic B[a]P exposure may impair the learning and memory ability in rats, which is related to the downregulation of hippocampal Ach level.</p>

Combined postconditioning with ischemia and α7nAChR agonist produces an enhanced protection against rat myocardial ischemia reperfusion injury / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Inflammation is one of important mechanisms for myocardial ischemia reperfusion injury (IRI). Ischemia postconditioning (IPOC) can protect the heart against IRI by inhibiting inflammation, but its cardioprotection is weaker than that of ischemia preconditioning. Recently, the α7 subunit-containing nicotinic acetylcholine receptor (α7nAChR) agonist has shown anti-inflammatory effects in many diseases related to inflammation. This randomized controlled experiment was designed to evaluate whether combined postconditioning with IPOC and the α7nAChR agonist could produce an enhanced cardioprotection in a rat in vivo model of acute myocardial IRI.</p><p><b>METHODS</b>Fifty Sprague-Dawley rats were randomly divided into five equal groups: sham group, control group, IPOC group, α7nAChR agonist postconditioning group (APOC group) and combined postconditioning with IPOC and α7nAChR agonist group (combined group). Hemodynamic parameters were recorded during the periods of ischemia and reperfusion. Serum concentrations of troponin I (TnI), tumor necrosis factor α (TNF-α) and high-mobility group box 1 (HMGB-1) at 180 minutes after reperfusion were assayed in all groups. At the end of the experiment, the infarct size was assessed from excised hearts by Evans blue and triphenyl tetrazolium chloride staining.</p><p><b>RESULTS</b>As compared to the sham group, the infarct size in the other four groups was significantly increased, serum levels of TnI, TNF-α and HMGB1 in the control group and TNF-α, HMGB1 in the IPOC group were significantly increased. The infarct size and serum concentrations of TNF-α, HMGB1 and TnI in the IPOC, APOC and combined groups were significantly lower than those in the control group. As compared to the IPOC group, the infarct size in the combined group was significantly decreased, serum concentrations of TnI, TNF-α and HMGB1 in the APOC and combined groups were significantly reduced. Although the infarct size was significantly smaller in the combined group than in the APOC group, serum levels of TNF-α and HMGB1 were significantly higher in the combined group than in the APOC group.</p><p><b>CONCLUSIONS</b>In a rat in vivo model of acute myocardial IRI, combined postconditioning with IPOC and the α7nAChR agonist can produce enhanced protection against myocardial IRI by increasing the anti-inflammatory effect.</p>

Influence of inhibited α7 nicotinic acetylcholine receptor gene expression on the production of β-amyloid peptide in SH-SY5Y cells / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the influence of inhibited α7 neuronal nicotinic acetylcholine receptor (nAChR) by small interference RNA (siRNA) in SH-SY5Y cells and to explore the connection of these changes with the β-amyloid precursor protein (APP) metabolism and the pathogenesis of Alzheimer's disease (AD).</p><p><b>METHODS</b>The siRNA of α7 nAChR was transfected into SH-SY5Y cells, and the expression of α7 nAChR and two subtypes of β-secretases (BACE1 and BACE2) at mRNA and protein levels was studied by real-time PCR and Western blot, respectively. The variation of Aβ(1-42) content was detected by ELISA.</p><p><b>RESULTS</b>As compared with controls, the expression of α7 nAChR at mRNA and protein levels in the SH-SY5Y cells transfected with the α7 nAChR siRNA were decreased by 84% and 79% (P < 0.01), respectively. The expressions of BACE1 mRNA and protein levels was increased by 527% and 71% (P < 0.01), respectively, while the expression of BACE2 decreased by 58% and 75% (P < 0.01), respectively. The Aβ(1-42) content increased by 208% (P < 0.01).</p><p><b>CONCLUSIONS</b>An inhibited α7 nAChR mRNA induced by siRNA may markedly stimulate the production of Aβ through the mechanism of increased expression of BACE1 and inhibited expression of BACE2, which may be related to the pathogenesis of AD.</p>

Influence of APP(SWE) transfection on nicotinic receptors in cultured neuronal cells / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the influence of APP(SWE) on the expression of neuronal acetylcholine receptors (nAChRs) and its relationship with Alzheimer's disease (AD).</p><p><b>METHODS</b>APP(SWE), carried the Swedish family AD double mutants, were transfected into SH-SY5Y cells and primary cultured neurons from rat brains to build a cellular model of AD. The mRNA levels of APP and nAChRs, and the protein levels of total APP, αAPPs and nAChRs in the cultured cells were measured using real-time PCR and Western blot, respectively. The numbers of α3 nAChR were determined by receptor-[³H]epibatidine binding assay.</p><p><b>RESULTS</b>Increased expressions of Swedish 670/671 APP at mRNA and protein levels, and down-regulation of αAPPs were observed in both of the cultured neuronal cells transfected with APP(SWE). A significant increase of α7 nAChR expression at protein and mRNA levels was detected in the APP(SWE) transfected SH-SY5Y cells. On the other hand, after transfection with APP(SWE), the expressions of α3 nAChR at protein and mRNA levels in SH-SY5Y cells, and α4 nAChR at mRNA level in primary cultured neurons were inhibited. In addition, the numbers of receptor binding sites were deceased in SH-SY5Y cells overexpressing with APP(SWE).</p><p><b>CONCLUSION</b>Overexpression of APP(SWE) can decrease αAPPs and modify nAChRs by increasing expression of α7 nAChR and decreasing α3 and α4 nAChRs, which might play an important role in the pathogenesis of AD.</p>

Role of cholinergic anti-inflammatory pathway in regulating host response and its interventional strategy for inflammatory diseases / 中华创伤杂志(英文版)

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.

Electrophysiological characteristics of the open state of neuronal alpha4beta2, alpha4beta4 and alpha7-nicotinic acetylcholine receptors / 中国应用生理学杂志

<p><b>AIM</b>To establish the whole-cell recording techniques of the neuronal alpha4beta2, alpha4beta4, and alpha7-nicotinic acetylcholine receptors heterologously expressed in SH-EP1 cell line and discuss the electrophysiological characteristics of their open states.</p><p><b>METHODS</b>The cells were cultured with DEME medium(high glucose) and suitable for electrophysiological experiments three days after passage. The receptors were induced from resting states into open states by rapid application of nicotine (alpha4beta2, alpha4beta4) or choline (alpha7).</p><p><b>RESULTS</b>The SH-EP1 cells cultured by this method were in good conditions and expressed plenty of receptors. Alpha4beta2, alph4beta4 and alpha7 inward currents could be induced by rapid application of agonists but had different dynamic processes against time. All the three types of currents were dose and voltage-dependent and had inward rectification property.</p><p><b>CONCLUSION</b>The open states of neuronal alpha4beta2, alpha4beta4, and alpha7-nicotinic acetylcholine receptors and their transitions have distinct characteristics and the inward currents of all this three types of receptors are dose and voltage-dependent and have inward rectification property.</p>

The transmission disequilibrium analysis between neuronal nicotinic acetylcholine receptor alpha 7 subunit gene polymorphisms and schizophrenia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the association between neuronal nicotinic acetylcholine receptor alpha 7 subunit (CHRNA7) gene and schizophrenia.</p><p><b>METHODS</b>The three polymorphisms rs2337980, rs1909884, rs883473 in CHRNA7 gene were detected based on PCR and polyacrylamide gel microarray in 129 schizophrenic trios. The results of genotyping were analyzed by haplotype relative risk analysis based on haplotype(HHRR), transmission disequilibrium test(TDT) and hyplotype analysis.</p><p><b>RESULTS</b>(1)The HHRR analysis suggested that there was significant differences in rs2337980 allele frequencies between schizophrenia group and dummy control group(P= 0.017); (2)In TDT test, there may be transmission disequilibrium between rs2337980 and schizophrenia, the heterozygous parents excessively transferred the C allele to patients (P= 0.021); (3)The haplotype between rs2337980 and rs1909884 as well as the hyplotype among rs2337980, rs1909884 and rs883473 may have significant association with schizophrenia (global P= 0.034; global P= 0.027), the T-C and T-C-T hyplotype may have transmission disequilibrium with schizophrenia.</p><p><b>CONCLUSION</b>There may be association between CHRNA7 gene polymorphisms and schizophrenia, the variant allele T in rs2337980 may have a protective effect to schizophrenia.</p>

Mechanism of conditioned immune response in curing bronchial asthma in mice / 中华儿科杂志

<p><b>OBJECTIVE</b>To understand the mechanism of effect of conditioned immune response in curing bronchial asthma.</p><p><b>METHODS</b>An experimental asthma modal was produced on healthy BALB/C mice (female, 4 - 6 weeks old) by sensitization and stimulation with ovalbumin (OV A). Totally 105 mice were divided into 7 groups randomly with 15 in each and treated differently: in group CIR(1), noise was used as conditioned stimulus (CS) and budesonide and salbutamol as unconditioned stimulus (UCS) respectively, a conditioned immune response model of mice with asthma was established by the combination of CS and UCS 7 times (7 days), then the mice were given CS only, and the combination were given once a week for 20 weeks. In group CIR(2) saccharin (SAC) was taken as CS, and the other treatments were the same as the group CIR(1). In the group of conventional therapy, the mice were given inhalation of nebulized budesonide and salbutamol only for 20 weeks. In the group of lower dose conventional therapy, the mice were given nebulized inhalation of budesonide and salbutamol for the first 7 days, then once a week for 20 weeks. In the noise group the mice were given noise only everyday for 20 weeks. In SAC group the mice were treated with SAC only everyday for 20 weeks. In the blank control group the mice were treated with placebo for 20 weeks. The mice in all the groups were stimulated with OVA once a day. The mice in the healthy control group were given PBS inhalation for 20 weeks. After 20 weeks therapy, the bronchoalveolar lavage fluid (BALF) was taken for eosinophils (EOS) counting. The spleens were taken to obtain CD4(+)T lymphocytes and the expression of neuronal acetylcholine receptor alpha 7 (nAChRalpha7), IL-4, IFN-gamma and IL-17 were detected by flow cytometry.</p><p><b>RESULTS</b>(1) The percent of EOS of groups CIR(1), CIR(2), conventional therapy and healthy control was much lower than that of blank control (P < 0.01), and there was no significant difference among groups CIR(1), CIR(2) and conventional therapy (P > 0.05). (2) The expression of nAChRalpha7, IL-4 and IL-17 of groups CIR(1), CIR(2), conventional therapy and healthy control was much lower than that in blank control group, IFN-gamma was much higher (P < 0.01), and no significant difference was found among groups CIR(1), CIR(2) and conventional therapy (P > 0.05). There was a positive correlation between nAChRalpha7 and IL-4 (r = 0.76, P < 0.01), nAChRalpha7 and IL-17 (r = 0.46, P < 0.01). There was a negative correlation between nAChRalpha7 and IFN-gamma (r = 0.69, P < 0.01). (3) In the groups treated with lower dose of conventional therapy, noise, SAC and blank control, the epithelial tissue of airway were much thicker, the lumens were much narrower, and inflammatory cells and collagen fibers were much more than in the healthy control group, and after therapy, the inflammation in groups CIR(1), CIR(2) and conventional therapy was significantly improved.</p><p><b>CONCLUSION</b>The conditioned immune response models established by both noise and SAC as CS and budesonide and salbutamol as UCS can downregulate nAChRalpha7 on CD4(+)T lymphocytes, regulate the function of CD4(+)T lymphocytes, and achieve the same therapeutic efficacy in treatment of asthma.</p>