Increased Choline Acetyltransferase Research Articles

Anti-Amnesic Effect of Agastache rugosa on Scopolamine-Induced Memory Impairment in Mice.

Agastache rugosa, a traditional Asian herbal medicine, is primarily used for digestive problems; yet, its cognitive benefits remain unexplored. This study evaluated the anti-amnesic effects of A. rugosa extract (ARE) on scopolamine (SCO)-induced memory impairment in mice. Mice received 100 or 200 mg/kg ARE orally for 5 days, followed by SCO injection. The ARE demonstrated significant antioxidant (DPPH IC50: 75.3 µg/mL) and anti-inflammatory effects (NO reduction). Furthermore, the ARE significantly improved memory performance in the passive avoidance test (escape latency: 157.2 s vs. 536.9 s), the novel object recognition test (novel object preference: 47.6% vs. 66.3%) and the Morris water maze (time spent in the target quadrant: 30.0% vs. 45.1%). The ARE reduced hippocampal acetylcholinesterase activity (1.8-fold vs. 1.1-fold) while increasing choline acetyltransferase (0.4-fold vs. 1.0-fold) and muscarinic acetylcholine receptor subtype I (0.3-fold vs. 1.6-fold) expression. The ARE improved hippocampal neurogenesis via doublecortin- (0.4-fold vs. 1.1-fold) and KI-67-positive (6.3 vs. 12.0) cells. Therefore, the ARE exerts protective effects against cognitive decline through cholinergic system modulation and antioxidant activity, supporting its potential use as a cognitive enhancer.

Agent Orange Causes Metabolic Dysfunction and Molecular Pathology Reminiscent of Alzheimer's Disease.

Agent Orange, an herbicide used during the Vietnam War, contains 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). Agent Orange has teratogenic and carcinogenic effects, and population-based studies suggest Agent Orange exposures lead to higher rates of toxic and degenerative pathologies in the peripheral and central nervous system (CNS). This study examines the potential contribution of Agent Orange exposures to neurodegeneration. Human CNS-derived neuroepithelial cells (PNET2) treated with 2,4-D and 2,4,5-T were evaluated for viability, mitochondrial function, and Alzheimer's disease (AD)-related proteins. Treatment with 250μg/ml 2,4-D or 2,4,5-T significantly impaired mitochondrial function, caused degenerative morphological changes, and reduced viability in PNET2 cells. Correspondingly, glyceraldehyde-3-phosphate dehydrogenase expression which is insulin-regulated and marks the integrity of carbohydrate metabolism, was significantly inhibited while 4-hydroxy-2-nonenal, a marker of lipid peroxidation, was increased. Tau neuronal cytoskeletal protein was significantly reduced by 2,4,5-T, and relative tau phosphorylation was progressively elevated by 2,4,5-T followed by 2,4-D treatment relative to control. Amyloid-β protein precursor (AβPP) was increased by 2,4,5-T and 2,4-D, and 2,4,5-T caused a statistical trend (0.05 < p<0.10) increase in Aβ. Finally, altered cholinergic function due to 2,4,5-T and 2,4-D exposures was marked by significantly increased choline acetyltransferase and decreased acetylcholinesterase expression, corresponding with responses in early-stage AD. Exposures to Agent Orange herbicidal chemicals rapidly damage CNS neurons, initiating a path toward AD-type neurodegeneration. Additional research is needed to understand the permanency of these neuropathologic processes and the added risks of developing AD in Agent Orange-exposed aging Vietnam Veterans.

Galantamine ameliorates hyperoxia-induced brain injury in neonatal mice.

Prolonged oxygen therapy in preterm infants often leads to cognitive impairment. Hyperoxia leads to excess free radical production with subsequent neuroinflammation, astrogliosis, microgliosis and apoptosis. We hypothesized that Galantamine, an acetyl choline esterase inhibitor and an FDA approved treatment of Alzheimer's disease, will reduce hyperoxic brain injury in neonatal mice and will improve learning and memory. Mouse pups at postnatal day 1 (P1) were placed in a hyperoxia chamber (FiO2 95%) for 7 days. Pups were injected IP daily with Galantamine (5 mg/kg/dose) or saline for 7 days. Hyperoxia caused significant neurodegeneration in cholinergic nuclei of the basal forebrain cholinergic system (BFCS), laterodorsal tegmental (LDT) nucleus and nucleus ambiguus (NA). Galantamine ameliorated this neuronal loss. Treated hyperoxic group showed a significant increase of choline acetyl transferase (ChAT) expression and a decrease of acetyl choline esterase activity, thus increasing acetyl choline levels in hyperoxia environment. Hyperoxia increased pro-inflammatory cytokines namely IL -1β, IL-6 and TNF α, HMGB1, NF-κB activation. Galantamine showed its potent anti- inflammatory effect, by blunting cytokines surges among treated group. Treatment with Galantamine increased myelination while reducing apoptosis, microgliosis, astrogliosis and ROS production. Long term neurobehavioral outcomes at P60 showed improved locomotor activity, coordination, learning and memory, along with increased hippocampal volumes on MRI with Galantamine treated versus non treated hyperoxia group. Together our findings suggest a potential therapeutic role for Galantamine in attenuating hyperoxia-induced brain injury.

Vagal-mAChR4 signaling promotes Friend virus complex (FV)-induced acute erythroleukemia

Erythroleukemia belongs to acute myeloid leukemia (AML) type 6 (M6), and treatment remains difficult due to the poor prognosis of the disease. Friend virus (FV) is a complex of two viruses: Friend murine leukemia virus (F-MuLV) strain along with a defective spleen focus-forming virus (SFFV), which can induce acute erythroleukemia in mice. We have previously reported that activation of vagal α7 nicotinic acetylcholine receptor (nAChR) signaling promotes HIV-1 transcription. Whether vagal muscarinic signaling mediates FV-induced erythroleukemia and the underlying mechanisms remain unclear. In this study, sham and vagotomized mice were intraperitoneally injected with FV. FV infection caused anemia in sham mice, and vagotomy reversed this change. FV infection increased erythroblasts ProE, EryA, and EryB cells in the spleen, and these changes were blocked by vagotomy. In bone marrow, FV infection reduced EryC cells in sham mice, an effect that was counteracted by vagotomy. FV infection increased choline acetyltransferase (ChAT) expression in splenic CD4+ and CD8+ T cells, and this change was reversed by vagotomy. Furthermore, the increase of EryA and EryB cells in spleen of FV-infected wild-type mice was reversed after deletion of ChAT in CD4+ T cells. In bone marrow, FV infection reduced EryB and EryC cells in sham mice, whereas lack of ChAT in CD4+ T cells did not affect this change. Activation of muscarinic acetylcholine receptor 4 (mAChR4) by clozapine N-oxide (CNO) significantly increased EryB in the spleen but decreased the EryC cell population in the bone marrow of FV-infected mice. Thus, vagal-mAChR4 signaling in the spleen and bone marrow synergistically promotes the pathogenesis of acute erythroleukemia. We uncover an unrecognized mechanism of neuromodulation in erythroleukemia.

Early Signs of Neuroinflammation in the Postnatal Wobbler Mouse Model of Amyotrophic Lateral Sclerosis.

The Wobbler mouse is an accepted model of sporadic amyotrophic lateral sclerosis. The spinal cord of clinically symptomatic animals (3-5months old) shows vacuolar motoneuron degeneration, inflammation, and gliosis accompanied by motor impairment. However, data are not conclusive concerning pathological changes appearing early after birth. To answer this question, we used postnatal day (PND) 6 genotyped Wobbler pups to determine abnormalities of glia and neurons at this early age period in the spinal cord. We found astrogliosis, microgliosis with morphophenotypic changes pointing to active ameboid microglia, enhanced expression of the proinflammatory markers TLR4, NFkB, TNF, and inducible nitric oxide synthase. The astrocytic enzyme glutamine synthase and the glutamate-aspartate transporter GLAST were also reduced in PND 6 Wobbler pups, suggesting excitotoxicity due to impaired glutamate homeostasis. At the neuronal level, PND 6 Wobblers showed swollen soma, increased choline acetyltransferase immunofluorescence staining, and low expression of the neuronal nuclear antigen NeuN. However, vacuolated motoneurons, a typical signature of older clinically symptomatic Wobbler mice, were absent in the spinal cord of PND 6 Wobblers. The results suggest predominance of neuroinflammation and abnormalities of microglia and astrocytes at this early period of Wobbler life, accompanied by some neuronal changes. Data support the non-cell autonomous hypothesis of the Wobbler disorder, and bring useful information with regard to intervening molecular inflammatory mechanisms at the beginning stage of human motoneuron degenerative diseases.

Hypoglycemic Effect of Electroacupuncture at ST25 Through Neural Regulation of the Pancreatic Intrinsic Nervous System

Electroacupuncture (EA) is considered to have potential antidiabetic effects; however, the role of the pancreatic intrinsic nervous system (PINS) in EA-induced amelioration of type 2 diabetes (T2DM) remains unclear. Therefore, we investigated whether EA at ST25 exerts any beneficial effects on insulin resistance (IR), inflammation severity, and pancreatic β cell function via the PINS in a rat model of a high-fat diet-streptozotocin (HFD/STZ)-induced diabetes. To this end, Sprague Dawley rats were fed with HFD to induce IR, followed by STZ (35 mg/kg, i.p.) injection to establish the T2DM model. After hyperglycemia was confirmed as fasting glucose level > 16.7 mmol/L, the rats were treated with EA (2 mA, 2/15 Hz) for the next 28 days. Model rats showed increased serum glucose, insulin, IR, and TNF-α levels with a concomitant decrease in β cell function. Microscopy examination of the pancreas revealed pathological changes in islets, which reverted to near-normal levels after EA at ST25. EA improved islet cell morphology by increasing islet area and reducing vacuolation. EA at ST25 decreased transient receptor potential vanilloid 1 (TRPV1) and increased substance P (SP) and calcitonin gene-related peptide (CGRP) expression. Subsequently, insulin secretion decreased and impaired pancreatic endocrine function was restored through the TRPV1 channel (SP/CGRP)-insulin circuit. EA increased choline acetyltransferase and neuropeptide Y expression and controlled inflammation. It also enhanced the cocaine and amphetamine-regulated transcript prepropeptide expression and promoted glucagon-like peptide-1 secretion. Additionally, the electrophysiological activity of PINS during acupuncture (2.71 ± 1.72 Hz) was significantly increased compared to the pre-acupuncture frequency (0.32 ± 0.37 Hz, P < 0.05). Thus, our study demonstrated the beneficial effect of EA on β cell dysfunction via the PINS in rat models of HFD-STZ-induced T2DM.

Electroacupuncture improves cardiac function and reduces infarct size by modulating cardiac autonomic remodeling in a mouse model of myocardial ischemia.

Sympathetic and parasympathetic nerve remodeling play an important role in cardiac function after myocardial ischemia (MI) injury. Increasing evidence indicates that electroacupuncture (EA) can regulate cardiac function by modulating the autonomic nervous system (ANS), but little is known about its effectiveness on neural remodeling post-MI. To investigate the role of EA in ANS remodeling post-MI. Adult male C57/BL6 mice were equally divided into the Control (Ctrl), MI and EA groups after generating the MI model by ligating the left anterior descending (LAD) coronary artery. Echocardiography and 2,3,5-triphenyltetrazolium (TTC) staining were employed to evaluate cardiac function and infarct size after EA treatment for five consecutive days. Serum norepinephrine (NE) levels were measured by ELISA to quantify sympathetic activation. Then, ANS remodeling was detected by immunohistochemistry (IHC), RT-qPCR, and Western blotting. Our preliminary findings showed that EA increased ejection fraction and fractional shortening and reduced infarct area after MI injury. Serum NE levels in the EA group were significantly decreased compared with those in the MI group. IHC staining results demonstrated that the density of growth associated protein (GAP)43 and tyrosine hydroxylase (TH) positive nerve fibers in the EA group were decreased with increased choline acetyltransferase (CHAT) and vesicular acetylcholine transporter (VACHT). Meanwhile, the results verified that mRNA and protein expression of GAP43 and TH were significantly inhibited by EA treatment in the MI mice, accompanied by elevated CHAT and VACHT. EA treatment could improve cardiac function and reduce infarct size by modulating sympathetic and parasympathetic nerve remodeling post-MI, thus helping the cardiac ANS reach a new balance to try to protect the heart from further possible injury.

ILC3-derived acetylcholine promotes protease-driven allergic lung pathology

ILC3-derived acetylcholine promotes protease-driven allergic lung pathology

Prosaposin and its receptors GRP37 and GPR37L1 show increased immunoreactivity in the facial nucleus following facial nerve transection.

Neurotrophic factor prosaposin (PS) is a precursor for saposins A, B, C, and D, which are activators for specific sphingolipid hydrolases in lysosomes. Both saposins and PS are widely contained in various tissues. The brain, skeletal muscle, and heart cells predominantly contain unprocessed PS rather than saposins. PS and PS-derived peptides stimulate neuritogenesis and increase choline acetyltransferase activity in neuroblastoma cells and prevent programmed cell death in neurons. We previously detected increases in PS immunoactivity and its mRNA in the rat facial nucleus following facial nerve transection. PS mRNA expression increased not only in facial motoneurons, but also in microglia during facial nerve regeneration. In the present study, we examined the changes in immunoreactivity of the PS receptors GPR37 and GPR37L1 in the rat facial nucleus following facial nerve transection. Following facial nerve transection, many small Iba1- and glial fibrillary acidic protein (GFAP)-positive cells with strong GPR37L1 immunoreactivity, including microglia and astrocytes, were observed predominately on the operated side. These results indicate that GPR37 mainly works in neurons, whereas GPR37L1 is predominant in microglia or astrocytes, and suggest that increased PS in damaged neurons stimulates microglia or astrocytes via PS receptor GPR37L1 to produce neurotrophic factors for neuronal recovery.

Walnut Oil Prevents Scopolamine-Induced Memory Dysfunction in a Mouse Model.

For thousands of years, it has been widely believed that walnut is a kind of nut that has benefits for the human body. Walnut oil, accounting for about 70% of walnut, mainly consists of polyunsaturated fatty acids. To investigate the effect of walnut oil on memory impairment in mice, scopolamine (3 mg/kg body weight/d) was used to establish the animal model during Morris Water Maze (MWM) tests. Walnut oil was administrated orally at 10 mL/kg body weight/d for 8 consecutive weeks. The results showed that walnut oil treatment ameliorated the behavior of the memory-impaired mice in the MWM test. Additionally, walnut oil obviously inhibited acetylcholinesterase activity (1.26 ± 0.12 U/mg prot) (p = 0.013) and increased choline acetyltransferase activity (129.75 ± 6.76 U/mg tissue wet weight) in the brains of scopolamine-treated mice (p = 0.024), suggesting that walnut oil could prevent cholinergic function damage in mice brains. Furthermore, walnut oil remarkably prevented the decrease in total superoxide dismutase activity (93.30 ± 5.50 U/mg prot) (p = 0.006) and glutathione content (110.45 ± 17.70 mg/g prot) (p = 0.047) and the increase of malondialdehyde content (13.79 ± 0.96 nmol/mg prot) (p = 0.001) in the brain of scopolamine-treated mice, indicating that walnut oil could inhibit oxidative stress in the brain of mice. Furthermore, walnut oil prevented histological changes of neurons in hippocampal CA1 and CA3 regions induced by scopolamine. These findings indicate that walnut oil could prevent memory impairment in mice, which might be a potential way for the prevention of memory dysfunctions.

Effect of Aged Garlic Ethyl Acetate Extract on Oxidative Stress and Cholinergic Function of Scopolamine-Induced Cognitive Impairment in Mice.

This study was performed to investigate the effect of aged black garlic ethyl acetate extract on scopolamine-induced cognitive impairment in mice. Aged garlic ethyl acetate extract (BG) was administrated at a dose of 25 or 50 mg/ kg in scopolamine-induced mice. Cognitive ability was evaluated using a Morris water maze test and a passive avoidance test. BGs (50 mg/kg) shortened the latency time that was increased by scopolamine and increased the platform crossing numbers that was significantly shortened by scopolamine after 5 days training in the Morris water maze test (P<0.05). BG (50 mg/kg) also significantly prolonged the latency time in the passive avoidance test (P<0.05). Result from biochemical analysis showed that BG increased levels of glutathione, glutathione peroxidase activity, and glutathione reductase activity, whereas BG significantly inhibited lipid peroxidation (P<0.05). BG also attenuated cholinergic degradation through inhibiting acetylcholinesterase activity and increasing choline acetyltransferase activity (P<0.05). In conclusion, BG protected against scopolamine-induced cognitive impairment through decreasing oxidative damage and regulating cholinergic function in the brains of mice. BG may therefore be a beneficial food for protecting against neurodegeneration such as Alzheimer’s disease.

Jia-Wei-Kai-Xin-San, an Herbal Medicine Formula, Ameliorates Cognitive Deficits via Modulating Metabolism of Beta Amyloid Protein and Neurotrophic Factors in Hippocampus of Aβ1-42 Induced Cognitive Deficit Mice.

Jia-Wei-Kai-Xin-San (JWKXS) is a Chinese medicine formula applied for treating morbid forgetfulness in ancient China. Today, this formula is frequently applied for Alzheimer’s disease and vascular dementia (VD) in clinic. Here, we developed it as granules and aimed to evaluate its anti-AD effect on β amyloid protein 1–42 (Aβ1-42) induced cognitive deficit mice and reveal the possible molecular mechanisms. Firstly, daily intra-gastric administration of chemically standardized of JWKXS granules for 7 days significantly ameliorated the cognitive deficit symptoms and inhibited cell apoptosis in hippocampus on Aβ1-42 injection mice. JWKXS granules significantly decreased Aβ level, increased superoxide dismutase activity and decreased malondialdehyde level in hippocampus of model mice. It also restored acetylcholine amounts, inhibited acetylcholinesterase activities and increased choline acetyltransferase activities. In addition, JWKXS granules enabled the transformation of precursors of NGF and BDNF into mature forms. Furthermore, JWKXS granules could regulate gene expressions related to Aβ production, transportation, degradation and neurotrophic factor transformation, which led to down-regulation of Aβ and up-regulation of NGF and BDNF. These findings suggested that JWKXS granules ameliorated cognitive deficit via decreasing Aβ levels, protecting neuron from oxidation damages and nourishing neuron, which could serve as alternative medicine for patients suffering from AD.

Cholinergic mechanisms in an organic dust model simulating an acute exacerbation in patients with COPD.

BackgroundExposure in a pig barn induces airway inflammation that has similarities with the response observed in acute exacerbations in COPD.MethodsA total of 15 smokers with COPD and 15 healthy non-smokers were exposed for 2 hours in a pig barn (in vivo exposure). Symptoms were assessed, lung function measured, and blood and sputum samples taken before and after exposure. Blood neutrophils were isolated and stimulated ex vivo with dust from a pig barn and acetylcholine, and inflammatory markers were analyzed.ResultsIn vivo exposure caused more symptoms and greater lung function fall in COPD patients than in controls. Baseline concentrations of MMP9, TIMP1, IL6, CXCL8, in sputum and neutrophil blood count were higher in COPD patients than in controls. In vivo exposure increased MMP9, TIMP1, IL6, CXCL8, TNFα, and LTB4 in sputum and MMP9 and IL6 in blood, with no difference between the groups, and serum CRP increased more in COPD subjects. Expression of choline acetyltransferase and acetylcholinesterase on sputum and blood cells was similar in the groups and uninfluenced by in vivo exposure. Dust exposure ex vivo increased choline acetyltransferase expression in neutrophils, but the dust and acetylcholine response did not differ between the groups before and after in vivo exposure.ConclusionCOPD patients exposed in a pig barn experience symptoms similar to those in acute exacerbations and lung function deterioration that is unrelated to bronchial responsiveness. Cholinergic mechanisms are involved in the inflammatory response to dust, with no difference between COPD and non-smokers.

Effects of vitamin D3 supplementation on cognition and blood lipids: a 12-month randomised, double-blind, placebo-controlled trial

Alzheimer’s disease (AD) is the leading cause of dementia and loss of autonomy and independency in the elderly.1 Currently, no effective pharmacological interventions change the onset or progression of AD.2...

Stereoselective glucuronidation metabolism, pharmacokinetics, anti-amnesic pharmacodynamics, and toxic properties of vasicine enantiomers in vitro and in vivo

Vasicine (VAS) is a potential natural cholinesterase inhibitor for treatment of Alzheimer's disease. Due to one chiral centre (C-3) presenting in molecule, VAS has two enantiomers, d-vasicine (d-VAS) and l-vasicine (l-VAS). The study was undertaken to investigate the stereoselective glucuronidation metabolism, pharmacokinetics, anti-amnesic effect and acute toxicity of VAS enantiomers. In results, the glucuronidation metabolic rate of l-VAS was faster than d-VAS in human liver microsomes and isoenzymes tests, and it was proved that the UDP-glucuronosyltransferase (UGT) 1A9 and UGT2B15 were the major metabolic enzymes for glucuronidation of l-VAS, while only UGT1A9 for d-VAS, which take responsibility of the significantly less metabolic affinity of d-VAS than l-VAS in HLM and rhUGT1A9. The plasma exposure of d-VAS in rats was 1.3-fold and 1.6-fold higher than that of l-VAS after intravenous and oral administration of d-VAS and l-VAS, respectively. And the plasma exposure of the major glucuronidation metabolite d-VASG was one of tenth of l-VASG or more less, no matter by intravenous or oral administration. Both d-VAS and l-VAS were exhibited promising acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities, and the BChE inhibitory activity of d-VAS with IC50 of 0.03 ± 0.001 μM was significantly stronger than that of l-VAS with IC50 of 0.98 ± 0.19 μM. The molecular docking results indicated that d-VAS and l-VAS could bind to the catalytic active site (CAS position) either of human AChE and BChE, and the BChE combing ability of d-VAS (the score of GBI/WAS dG −7.398) was stronger than that of l-VAS (the score of GBI/WAS dG −7.135). Both d-VAS and l-VAS could improving the learning and memory on scopolamine-induced memory deficits in mice. The content of acetylcholine (ACh) after oral administration d-VAS increased more than that of l-VAS in mice cortex, through inhibiting cholinesterase (ChE) and increasing choline acetyltransferase (ChAT). In addition, the LD50 value of d-VAS (282.51 mg·kg−1) was slight lower than l-VAS (319.75 mg·kg−1). These results indicated that VAS enantiomers displayed significantly stereoselective metabolic, pharmacokinetics, anti-amnesic effect and toxic properties in vitro and in vivo. The d-VAS might be the dominant configuration for treating Alzheimer's disease.

Ethanolic extract Ocimum sanctum. Enhances cognitive ability from young adulthood to middle aged mediated by increasing choline acetyl transferase activity in rat model

Patients with dementia are increasing steadily, cognitive impairment by dementia not only exclusively suffers by old people but also young to middle aged individuals. However, the mechanism of cognitive impairment occurs in young people is not understood. Further, current medication to impairment did not provide satisfactory results. Therefore, we investigated the potential role of Ocimum sanctum ethanolic extract to enhance cognitive ability in the rat in vivo model.Young to middle aged rats were divided into 3 groups (3, 6, 9 months old) were treated with (0, 50 and 100 mg/kg b.w.) O. sanctum for 45 days. We employed a behavioral assay to assess cognitive ability. Further, Nissl staining was performed to analyze hippocampus formation in dentate gyrus (DG), cornu ammonis 1 (CA1), cornu ammonis 3 (CA3). The expression and activity of ChAT in brain was analyzed by RT-PCR and ELISA. Our results showed that treatment of O. sanctum with a dosage of 100 mg/kg b.w. for 45 days induced the cognitive ability in nine months old rats. Further, we observed a significant increase in density of granular and pyramidal cells in DG, CA1, and CA3. These results were corroborated by an increase in the ChAT activity and gene expression in the rat model as well as HEK 293 cell culture model.Taken together, the administration of 100 mg/kg b.w. O.sanctum induced the expression of ChAT. The increased ChAT expression and activity may enhance the cognitive ability in 9 months old rats mimicking young and middle aged condition in humans.

Microsomal prostaglandin E synthase-1 gene deletion impairs neuro-immune circuitry of the cholinergic anti-inflammatory pathway in endotoxaemic mouse spleen.

The cholinergic anti-inflammatory pathway (CAP) is an innate neural reflex where parasympathetic and sympathetic nerves work jointly to control inflammation. Activation of CAP by vagus nerve stimulation (VNS) has paved way for novel therapeutic strategies in treating inflammatory diseases. Recently, we discovered that VNS mediated splenic acetylcholine (ACh) release and subsequent immunosuppression in response to LPS associated inflammation is impaired in mice lacking microsomal prostaglandin E synthase-1 (mPGES-1) expression, a key enzyme responsible for prostaglandin E2 synthesis. Here, we have further investigated the consequences of mPGES-1 deficiency on various molecular/cellular events in the spleen which is critical for the optimal functioning of VNS in endotoxaemic mice. First, VNS induced splenic norepinephrine (NE) release in both mPGES-1 (+/+) and (-/-) mice. Compared to mPGES-1 (+/+), immunomodulatory effects of NE on cytokines were strongly compromised in mPGES-1 (-/-) splenocytes. Interestingly, while LPS increased choline acetyltransferase (ChAT) protein level in mPGES-1 (+/+) splenocytes, it failed to exert similar effects in mPGES-1 (-/-) splenocytes despite unaltered β2 AR protein expression. In addition, nicotine inhibited TNFα release by LPS activated mPGES-1 (+/+) splenocytes in vitro. However, such immunosuppressive effects of nicotine were reversed both in mPGES-1 (-/-) mouse splenocytes and human PBMC treated with mPGES-1 inhibitor. In summary, our data implicate PGE2 as an important mediator of ACh synthesis and noradrenergic/cholinergic molecular events in the spleen that constitute a crucial part of the CAP immune regulation. Our results suggest a possible link between cholinergic and PG system of CAP that may be of clinical significance in VNS treatment.

Effect and mechanism of oyster hydrolytic peptides on spatial learning and memory in mice.

Oysters (Crassostrea talienwhanensis) contain large amounts of protein and exhibit many biological activities. This study was aimed at preparing oyster protein hydrolysates (OPH) and evaluating the OPH based on a spatial learning and memory capacity. A response surface methodology was employed to optimize hydrolysis conditions to determine the OPH with the highest AChE inhibitory activity, and the optimum extraction conditions were as follows: enzyme concentration of 1444.88 U g−1, pH of 7.38, extraction temperature of 45 °C, extraction time of 5.56 h and a water/material ratio of 2.45 : 1, and the minimum acetylcholinesterase (AChE) activity was 0.069 mM min−1. The spatial memory and learning abilities and passive avoidance in mice were determined by using the Morris water maze test and a dark/light avoidance test. Furthermore, the OPH group could relieve oxidative stress, reduce AChE levels, increase choline acetyltransferase (ChAT) levels and alleviate inflammatory reaction through reduction of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) levels. Additionally, up-regulated expressions of brain-derived neurotrophic factor (BDNF) and neural cell adhesion molecules (NCAM) were observed in mice treated with OPH. These findings suggested that OPH could be a functional food candidate to improve the learning and memory ability associated with oxidative stress and inflammatory reactions.

Acetylcholine precursor, citicoline (cytidine 5'-diphosphocholine), reduces hypoglycaemia-induced neuronal death in rats.

Citicoline (cytidine 5'-diphosphocholine) is an important precursor for the synthesis of neuronal plasma membrane phospholipids, mainly phosphatidylcholine. The administration of citicoline serves as a choline donor for the synthesis of acetylcholine. Citicoline has been shown to reduce the neuronal injury in animal models with cerebral ischaemia and in clinical trials of stroke patients. Citicoline is currently being investigated in a multicentre clinical trial. However, citicoline has not yet been examined the context of hypoglycaemia-induced neuronal death. To clarify the therapeutic impact of citicoline in hypoglycaemia-induced neuronal death, we used a rat model with insulin-induced hypoglycaemia. Acute hypoglycaemia was induced by i.p. injection of regular insulin (10Ukg-1 ) after overnight fasting, after which iso-electricity was maintained for 30minutes. Citicoline injections (500mg/kg, i.p.) were started immediately after glucose reperfusion. We found that post-treatment of citicoline resulted in significantly reduced neuronal death, oxidative injury and microglial activation in the hippocampus compared to vehicle-treated control groups at 7days after induced hypoglycaemia. Citicoline administration after hypoglycaemia decreased immunoglobulin leakage via blood-brain barrier disruption in the hippocampus compared to the vehicle group. Citicoline increased choline acetyltransferase expression for phosphatidylcholine synthesis after hypoglycaemia. Altogether, the present findings suggest that neuronal membrane stabilisation by citicoline administration can save neurones from the degeneration process after hypoglycaemia, as seen in several studies of ischaemia. Therefore, the results suggest that citicoline may have therapeutic potential to reduce hypoglycaemia-induced neuronal death.

Neuroprotective, Neurogenic, and Amyloid Beta Reducing Effect of a Novel Alpha 2-Adrenoblocker, Mesedin, on Astroglia and Neuronal Progenitors upon Hypoxia and Glutamate Exposure.

Locus coeruleus-noradrenergic system dysfunction is known to contribute to the progression of Alzheimer’s disease (AD). Besides a variety of reports showing the involvement of norepinephrine and its receptor systems in cognition, amyloid β (Aβ) metabolism, neuroinflammation, and neurogenesis, little is known about the contribution of the specific receptors to these actions. Here, we investigated the neurogenic and neuroprotective properties of a new α2 adrenoblocker, mesedin, in astroglial primary cultures (APC) from C57BL/6 and 3×Tg-AD mice. Our results demonstrate that mesedin rescues neuronal precursors and young neurons, and reduces the lactate dehydrogenase (LDH) release from astroglia under hypoxic and normoxic conditions. Mesedin also increased choline acetyltransferase, postsynaptic density marker 95 (PSD95), and Aβ-degrading enzyme neprilysin in the wild type APC, while in the 3×Tg-AD APC exposed to glutamate, it decreased the intracellular content of Aβ and enhanced the survival of synaptophysin-positive astroglia and neurons. These effects in APC can at least partially be attributed to the mesedin’s ability of increasing the expression of Interleukine(IL)-10, which is a potent anti-inflammatory, neuroprotective neurogenic, and Aβ metabolism enhancing factor. In summary, our data identify the neurogenic, neuroprotective, and anti-amyloidogenic action of mesedin in APC. Further in vivo studies are needed to estimate the therapeutic value of mesedin for AD.