OBJECTIVE: 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. METHODS: 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. RESULTS: 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). CONCLUSION 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.
Rats ; Male ; Animals ; Rats, Inbred SHR ; NF-kappa B/metabolism* ; Rats, Inbred WKY ; Electroacupuncture ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-6/metabolism* ; Neuroimmunomodulation ; alpha7 Nicotinic Acetylcholine Receptor ; Acetylcholine ; Fibrosis ; RNA, Messenger

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.
Acetylcholinesterase ; Animals ; Autophagy ; Brain Ischemia/metabolism* ; Cerebral Infarction ; Cognitive Dysfunction/drug therapy* ; Glutathione/metabolism* ; Glycosides ; Infarction, Middle Cerebral Artery/drug therapy* ; Neuroprotective Agents/therapeutic use* ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury/drug therapy* ; Stroke/drug therapy* ; Superoxide Dismutase/metabolism* ; alpha7 Nicotinic Acetylcholine Receptor

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.
Animals ; Disease Models, Animal ; Glycoproteins ; Mice ; Mice, Knockout ; Mice, Transgenic ; Tumor Necrosis Factor-alpha ; alpha7 Nicotinic Acetylcholine Receptor ; metabolism

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.
Acetylcholine ; Humans ; Inflammation ; Neuroimmunomodulation ; Sepsis ; Vagus Nerve Stimulation ; alpha7 Nicotinic Acetylcholine Receptor

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.
Animals ; Hippocampus ; cytology ; Mice ; Mice, Knockout ; Neurons ; physiology ; Phenotype ; Synaptic Transmission ; alpha7 Nicotinic Acetylcholine Receptor ; physiology

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.
Autonomic Nervous System ; physiology ; Heart ; physiopathology ; Humans ; Inflammation ; physiopathology ; Parasympathetic Nervous System ; physiology ; alpha7 Nicotinic Acetylcholine Receptor ; physiology

BACKGROUNDShensong 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.

METHODSEighteen 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.

RESULTSCompared 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.

CONCLUSIONSSSYX 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.

Acetylcholine ; blood ; Animals ; Atrial Fibrillation ; drug therapy ; metabolism ; Autonomic Pathways ; drug effects ; Blotting, Western ; Dogs ; Drugs, Chinese Herbal ; therapeutic use ; Electrophysiology ; Enzyme-Linked Immunosorbent Assay ; Heart Rate ; drug effects ; Immunohistochemistry ; Interleukin-6 ; blood ; Models, Animal ; Tumor Necrosis Factor-alpha ; blood ; alpha7 Nicotinic Acetylcholine Receptor ; blood

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.
Amyloid beta-Peptides ; Animals ; Cerebral Cortex ; Cognitive Dysfunction ; Hippocampus ; Learning ; Memory ; Nitric Oxide Synthase Type I ; Rats ; Rats, Sprague-Dawley ; alpha7 Nicotinic Acetylcholine Receptor

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.
Berberine ; pharmacology ; Glucose ; metabolism ; Hep G2 Cells ; Humans ; Hypoglycemic Agents ; pharmacology ; I-kappa B Kinase ; metabolism ; I-kappa B Proteins ; metabolism ; Insulin ; metabolism ; Insulin Resistance ; Interleukin-6 ; metabolism ; Transcription Factor RelA ; metabolism ; alpha7 Nicotinic Acetylcholine Receptor ; genetics ; metabolism

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.
alpha7 Nicotinic Acetylcholine Receptor ; Animals ; Blotting, Western ; Fluorescent Antibody Technique ; Hexamethonium ; Models, Animal ; Rats* ; Rats, Sprague-Dawley ; Receptors, Nicotinic* ; Urinary Bladder ; Urinary Bladder Neck Obstruction* ; Urinary Bladder, Overactive ; Urothelium