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Objective:To evaluate the role of glutamate receptor 2 (GluR2) in cognitive dysfunction induced by chronic neuroinflammation in mice.Methods:Sixty adult male C57BL/6 mice, aged 8-10 weeks, weighing 18-25 g, were divided into 4 groups ( n=15 each) using a random number table method: control + dimethyl sulfoxide (DMSO) group (group C+ DMSO), control + AMPA receptor selective non-competitive antagonist CFM-2 group (group C+ CFM-2), lipopolysaccharide (LPS)+ DMSO group and LPS + CFM-2 group.In C+ DMSO group and C+ CFM-2 group, normal saline 0.2 ml was intraperitoneally injected every day for 10 consecutive days, and 10% DMSO 0.165 ml and CFM-2 33 μmol/kg (diluted to 0.165 ml with 10% DMSO) were intraperitoneally injected, respectively, on the 10th day after injection of normal saline.In LPS + DMSO group and LPS + CFM-2 group, LPS 0.5 mg/kg (diluted to 0.2 ml with normal saline) was intraperitoneally injected every day for 10 consecutive days, and 10% DMSO 0.165 ml and CFM-2 33 μmol/kg (diluted to 0.165 ml with 10% DMSO) were intraperitoneally injected, respectively, after LPS injection on the 10th day.The Y-maze test was performed at 48 h after the end of administration, then the animals were sacrificed, and the hippocampal tissues were taken for determination of the expression of GluR2, ionized calcium binding adapter molecule 1 (Iba1), tumor necrosis factor-α (TNF-α) (by Western blot) and the number of microglia in hippocampal CA1 area (by immunofluorescence). Results:Compared with group C + DMSO, the percentage of spontaneous alternation was significantly decreased, the expression of GluR2, Iba1 and TNF-α in hippocampus was up-regulated, the number of microglia in hippocampal CA1 area was increased ( P<0.05), and no significant change was found in the parameters mentioned above in group LPS + DMSO ( P>0.05). Compared with group LPS + DMSO, the percentage of spontaneous alternation was significantly increased, the expression of GluR2, Iba1 and TNF-α in hippocampus was down-regulated, and the number of microglia in hippocampal CA1 area was decreased in group LPS+ CFM-2 ( P<0.05). Conclusions:GluR2 is involved in chronic neuroinflammation-induced cognitive dysfunction through activation of microglia in mice.
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Objective:To establish a tissue based assay and in-house cell based assay combined system to screen anti-metabotropic glutamate receptor 1 antibodies in a case of previously idiopathic encephalitis with prominent cerebellar ataxia and make the final diagnosis, and to summarize and analyze clinical characteristics and treatment response of the disease.Methods:A middle-aged woman admitted to Department of Neurology, People's Liberation Army General Hospical Accredited to the Sixth Medical Center in January 9, 2020, who presented with acute dizziness, unsteady gait and developed head titubation, repeated language and calculation impairment was reported. The patient′s serum and cerebrospinal fluid were firstly tested with commercial kits for conventional neural antibodies.Then samples were incubated with rat hippocampus, cerebellum and human embryonic kidney 293 cells transfected with metabotropic glutamate receptor 1 plasmid to screen extra antibodies by indirect immunofluorescence method. By reviewing literature, physical functions of metabotropic glutamate receptor 1 and clinical features of anti-metabotropic glutamate receptor 1 antibodies associated encephalitis were summarized.Results:The patient was neural antibodies negative with commercial kits. Further investigation showed neuropil staining pattern after her serum and cerebral spinal fluid were incubated with rat brain slices. The characteristic "Medusa head" staining pattern of Purkinje cells in cerebellum was also noticed. Along with her previous head titubation symptom, an in-house cell based assay using human embryonic kidney 293 cells transfected with metabotropic glutamate receptor 1 plasmid was developed and proved the existence of anti-metabotropic glutamate receptor 1 antibodies. The final diagnosis of anti-metabotropic glutamate receptor 1 antibodies associated encephalitis was made. One-year follow-up revealed her serum antibodies titers dramatically decreased and cerebrospinal fluid antibodies were negative after using steroids and intravenous immunoglobulin, but still left prominent cerebellum atrophy and severe ataxia.Conclusions:Anti-metabotropic glutamate receptor 1 antibodies may cause acute encephalitis. Cerebellar ataxia and head titubation are characteristic symptoms of metabotropic glutamate receptor 1 autoimmunity. The response to immunotherapies is limited and patients may have severe neurological deficits.
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Objective@#To evaluate the role of neuroligin 1 (NL-1) in trafficking of GluR1-containing AMPA receptor to cell membrane in spinal cord dorsal horns during remifentanil-induced hyperalgesia in mice with incisional pain.@*Methods@#Forty SPF healthy male C57BL/6J mice, aged 8-10 weeks, weighing 18-22 g, were divided into 5 groups (n=8 each) using a random number table method: control group (group C), NL1-shRNA plasmid group (group NL), incisional pain plus remifentanil group (group I+ R), incisional pain plus remifentanil plus blank vector group (group I+ R+ B), and incisional pain plus remifentanil plus NL-1-shRNA plasmid group (group I+ R+ NL). Negative lentivirus was intrathecally injected in group I+ R+ B.In NL and I+ R+ NL groups, 10 μl NL-1-shRNA lentivirus at 1×108 IFU/ml was intrathecally injected once a day for 3 consecutive days.Normal saline 10 μl was intrathecally injected at the same time point in C and I+ R groups.After transfection was stable, normal saline 0.1 ml was injected via the caudal vein for 4 consecutive times at 15 min intervals in C and NL groups.In I+ R, I+ R+ B and I+ R+ NL groups, 0.1 ml remifentanil 10 μg/kg was injected via the caudal vein for 4 consecutive times at 15 min intervals, and the model of incisional pain was established after the first administration.The mechanical paw withdrawal threshold (MWT) and tail-flick latency (TFL) were measured at 24 h before normal saline or remifentanil administration (T0) and at 3, 6, 24 and 48 h after the end of administration (T1-4). The animals were sacrificed after measurement of pain threshold at T4, and L4-6 segments of the spinal dorsal horn were then collected for determination of the expression of NL-1 protein and mRNA and AMPA receptors, and the ratio of AMPA receptor expression in the membrane protein to that in the total protein (m/t ratio) was calculated.@*Results@#Compared with group C, the MWT was significantly decreased, and TFL was shortened at T1-4, the expression of NL-1 protein and mRNA and GluR1-containing AMPA receptors in membrane and total proteins was up-regulated, and m/t ratio was increased in I+ R and I+ R+ B groups (P<0.05). Compared with I+ R and I+ R+ B groups, the MWT was significantly increased and TFL was prolonged at T1-4, the expression of NL-1 protein and mRNA and GluR1-containing AMPA receptors in membrane and total proteins was down-regulated, and m/t ratio was decreased in group I+ R+ NL (P<0.05).@*Conclusion@#NL-1 in spinal cord dorsal horns can promote the trafficking of GluR1-containing AMPA receptors to cell membrane, which is involved in the development and maintenance of remifentanil-induced hyperalgesia in mice with incisional pain.
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Objective To evaluate the role of neuroligin 1 (NL-1) in trafficking of GluR1-containing AMPA receptor to cell membrane in spinal cord dorsal horns during remifentanil-induced hyperalgesia in mice with incisional pain.Methods Forty SPF healthy male C57BL/6J mice,aged 8-10 weeks,weighing 18-22 g,were divided into 5 groups (n=8 each) using a random number table method:control group (group C),NL1-shRNA plasmid group (group NL),incisional pain plus remifentanil group (group I+R),incisional pain plus remifentanil plus blank vector group (group I+R+B),and incisional pain plus remifentanil plus NL-1-shRNA plasmid group (group I+R+NL).Negative lentivirus was intrathecally injected in group I+R+B.In NL and I+R+NL groups,10 μl NL-1-shRNA lentivirus at 1×10s IFU/ml was intrathecally injected once a day for 3 consecutive days.Normal saline 10 μl was intrathecally injected at the same time point in C and I+R groups.After transfection was stable,normal saline 0.1 ml was injected via the caudal vein for 4 consecutive times at 15 min intervals in C and NL groups.In I+R,I+R+B and I+R+NL groups,0.1 ml remifentanil 10 μg/kg was injected via the caudal vein for 4 consecutive times at 15 min intervals,and the model of incisional pain was established after the first administration.The mechanical paw withdrawal threshold (MWT) and tail-flick latency (TFL) were measured at 24 h before normal saline or remifentanil administration (T0) and at 3,6,24 and 48 h after the end of administration (T1-4).The animals were sacrificed after measurement of pain threshold at T4,and L4-6 segments of the spinal dorsal horn were then collected for determination of the expression of NL-1 protein and mRNA and AMPA receptors,and the ratio of AMPA receptor expression in the membrane protein to that in the total protein (m/t ratio) was calculated.Results Compared with group C,the MWT was significantly decreased,and TFL was shortened at T1-4,the expression of NL-1 protein and mRNA and GluR1-containing AMPA receptors in membrane and total proteins was up-regulated,and m/t ratio was increased in I+R and I+R+B groups (P＜0.05).Compared with I+R and I+R+B groups,the MWT was significantly increased and TFL was prolonged at T1-4,the expression of NL-1 protein and mRNA and GluR1-containing AMPA receptors in membrane and total proteins was down-regulated,and m/t ratio was decreased in group I+R+NL (P＜0.05).Conclusion NL-1 in spinal cord dorsal horns can promote the trafficking of GluR1-containing AMPA receptors to cell membrane,which is involved in the development and maintenance of remifentanil-induced hyperalgesia in mice with incisional pain.
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Objective To evaluate the role of group Ⅱ metabotropic glutamate receptors (mGluRs) in cognitive decline caused by multiple administrations of ketamine in mice and the relationship with hippocampal glycogen synthase kinase-3 beta (GSK-3β) expression.Methods Forty-five SPF healthy female C57BL/6 mice,aged 6-8 weeks,weighing 20-30 g,were randomized into 3 groups (n=15 each) using a random number table method:control group (group C),ketamine group (group K) and mGluR agonist LY354740 group (group L+K).In K and L+K groups,ketamine 30 mg/kg was intraperitoneally injected three times a day at an 30-min interval for 14 consecutive days.LY354740 was intraperitoneally injected at 30 min before the first injection of ketamine in group L+K.The equal volume of normal saline was given instead in group C.Morris water maze test was performed the day after the last administration.The mice were then sacrificed,and hippocampi were harvested to determine the expression of GSK3β,NR2A and postsynaptic density protein 95 (PSD95) by Western blot.Results Compared with group C,the escape latency was significantly prolonged,the time of staying at the original platform quadrant was shortened,the frequency of crossing the original platform was decreased,the expression of GSK3β3 and NR2A was up-regulated,and the expression of PSD95 was down-regulated in group K (P＜0.05),and no significant change was found in the parameters mentioned above in group L+K (P＞0.05).Compared with group K,the escape latency was significantly shortened,the time of staying at the original platform quadrant was prolonged,the frequency of crossing the original platform was increased,the expression of GSK3β and NR2A was down-regulated,and the expression of PSD95 was up-regulated in group L+K (P＜0.05).Conclusion Group Ⅱ mGluRs are involved in the process of cognitive decline caused by multiple administrations of ketamine in mice,which is associated with up-regulated expression of hippocampal GSK-3β.
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Objective To study the mechanism of central nervous system (CNS) injury in chronic fluorosis and the neuroprotective effect of chondroitin sulfate (CS).Methods Forty-eight female Sprague-Dawley rats weighting 90-120 g were divided into 8 groups according to body weight by random number table,6 rats in each group:control group,drinking tap water freely;low dose and high dose fluoride groups,freely drinking tap water with fluoride content of 10 and 50 mg/L,respectively;control + normal saline (NS),low dose fluoride + NS,and high dose fluoride + NS groups,each group was fed for 180 d,and treated with intraperitoneal injection of 0.66 mg/kg NS for 5 d (once a day);low dose fluoride + CS and high dose fluoride + CS groups,each group was fed for 180 d,0.66 mg/kg CS was injected intraperitoneally for 5 d (once a day).All groups were fed standard nutritive animal feed for 185 d and dissected for brain tissue.The pathologic change was observed after hematoxylin-eosin (HE)staining;the expression levels of phosphorylated extracellular signal-regulated protein kinase 1/2 (phospho-Erk1/2)and glutamate receptors 1,2 (GluR1,GluR2) in the brain cortex were detected by immunohistochemistry;the protein levels of Erk1/2,phospho-Erk1/2,GluR1,and GluR2 in the brain cortex were detected by Western blotting.Results Brain cortex of all rats in the fluoride groups showed eosinophilic degeneration,loss and disordered arrangement of neurons,and the brain morphological changes in each fluoride + CS groups were significantly improved compared with those in the fluoride groups.Immunohistochemistry results showed that compared with the control group [(0.44 ± 0.09)％,(1.49 ± 0.05)％,(2.51 ± 0.54)％],the expression levels of phospho-Erk1/2 [(1.47 ±0.09)％,(1.03 ± 0.05)％],and GluR2 [(2.37 ± 0.06)％,(3.38 ± 0.12)％] in the low dose and high dose fluoride groups were increased,and the expression levels of GluR1 [(1.49 ± 0.02)％,(0.99 ± 0.19)％] were decreased (P ＜ 0.05).Western blotting results showed that compared with the control group (1.00 ± 0.12,1.76 ± 0.33),the protein levels of Erk1/2 (3.10 ± 0.76,1.99 ± 0.01) and phospho-Erk1/2 (3.27 ± 0.25,2.67 ± 0.05) in low dose and high dose fluoride groups were significantly increased (P ＜ 0.05);compared with low dose fluoride group,the protein levels of Erk1/2,and phospho-Erk1/2 (1.30 ± 0.31,2.20 ± 0.34) in low dose fluoride + CS group decreased significantly (P ＜0.05).Compared with control group (1.86 ± 0.47,1.17 ± 0.27),the protein levels of GluR1 (1.09 ± 0.26,0.61 ± 0.14) in low dose and high dose fluoride groups decreased significantly,while the protein level of GluR2 (1.99 ± 0.42,3.38 ±0.27) increased significantly (P ＜ 0.05);compared with low dose and high dose fluoride groups,the protein levels of GluR2 in low dose fluoride + CS and high dose fluoride + CS groups (1.53 ± 0.41,2.65 ± 0.32) decreased significantly (P ＜ 0.05).The protein level of phospho-Erk1/2 was negatively correlated with GluR1 protein level (r =-0.975,-0.991,P ＜ 0.05) in low dose and high dose fluoride groups,and it was positively correlated with the protein level of GluR2 (r =0.986,0.993,P ＜ 0.05).Conclusion The CNS injury caused by chronic fluorosis may be related to GluR1 and GluR2 activated Erk1/2 signaling pathway,and CS has certain protection to the injury.
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MicroRNAs (miRNAs) are a class of short non-coding single-stranded RNAs.They can regulate gene expression at the post-transcriptional level by binding to the T-untranslated region of the target gene mRNA and participate in the regulation of almost all biological processes.Recent studies have shown that MiRNAs are widely involved in a variety of pathophysiological processes in ischemic brain injury,such as excitotoxicity,oxidative stress,inflammation,apoptosis,and cerebral edema,suggesting that they may serve as a biomarker for ischemic stroke,assisting early diagnosis and outcome assessment,and becoming a drug treatment target.
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Objective To explore effects of dizocilpine (MK-801) preconditioning on excitatory amino acids and inflammatory response in rats induced by cardiac arrest-cardiopulmonary resuscitation (CACPR).Methods 18 male Sprague Dawley (SD) rats were randomly divided into three groups:control group,CA group and CA + MK-801 group.To establish rat models of CA-CPR and keep samples of serum and specimens of brain tissues for following detection.The injury of neurons was observed by HE staining and expression of N-methyl-D-aspartic acid receptor (NMDAR) in brain tissues was detected by Western blot.The concentrations of interleukin 1 beta (IL-1 β) and tumor necrosis factor (TNF)-α in serum were detected by enzyme linked immunosorbent assay (ELISA).Results Neurons in CA group were disorganized,cells shrank,nuclei pyknosis,and cytoplasmic eosinophilia,accompanied by inflammatory cell infiltration.Preconditioning with MK-801 reduced the pathological damage of neuron and degree of macrophage infiltration.The relative expression of NMDAR protein in CA group were significantly higher than that in control group (907.9 ±24.9 vs 321.6 ± 18.4,P ＜0.001).Preconditioning with MK-801 significantly decreased the expression of NMDAR in CA + MK-801 group compared with that in CA group (512.4 ± 21.1 vs 907.9 ± 24.9).The CA group showed significantly increased concentrations of IL-1 β and TNF-α than that in control group (P ＜ 0.001),and this effect was abolished by preconditioning with MK-801.CA rats treated with MK-801 showed higher concentrations of IL-1 β and TNF-α than the control group.Conclusions Cardiac arrest causes pathological injury of neurons,up-regulates expression of NMDAR and aggravates inflammatory response.These results induce the apoptosis of nerve cells.Blocking glutamate receptor with MK-801 can inhibit expression of NMDAR,decrease level of cytokines,down-regulate inflammatory reaction degree therefore to protect the brain.
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Objective To evaluate the effect of sevoflurane preconditioning on the expression of metabotropic glutamate receptor type Ⅱ( mGluRⅡ) during focal cerebral ischemia-reperfusion ( I∕R) in rats. Methods Forty-eight clean-grade healthy male Sprague-Dawley rats were divided into 3 groups (n＝16 each) using a random number table method: sham operation group ( group S), cerebral I∕R group (group I∕R) and sevoflurane preconditioning group (group Sev). Rats were anesthetized with 10% chloral hydrate 3 ml∕kg. Focal cerebral I∕R was produced by occlusion of the right middle cerebral artery for 2 h fol-lowed by 24 h reperfusion. In group Sev, 2. 7% sevoflurane was inhaled for 1 h and 24 h later focal cerebral I∕R was produced. At 24 h after reperfusion, neurological deficit was scored, the cerebral infarct size was determined by TTC staining, the cell apoptosis in ischemic penumbra was observed by TUNEL, IκB-α ex-pression was detected by Western blot, and mGluRⅡexpression was determined by immunofluorescent stai-ning. The apoptosis rate was calculated. Results Compared with group S, the neurological deficit score, cerebral infarct size and apoptosis rate were significantly increased, the expression of mGluRⅡwas up-regu-lated, and the expression of IκB-α was down-regulated in I∕R and Sev groups ( P＜0. 05). Compared with group I∕R, the neurological deficit score, cerebral infarct size and apoptosis rate were significantly de-creased, the expression of mGluRⅡwas down-regulated, and the expression of IκB-α was up-regulated in group Sev (P＜0. 05). Conclusion Sevoflurane preconditioning reduces focal cerebral I∕R injury through inhibiting the expression of mGluRⅡ in rats.
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Resumen La encefalitis asociada a anticuerpos contra receptores N-metil-D-aspartato es un síndrome neurológico que se presenta más comúnmente en mujeres jóvenes y frecuentemente se asocia al teratoma de ovario. Se caracteriza por un cuadro clínico agudo con síntomas generales inespecíficos que evoluciona hacia deterioro neurológico, psicosis y convulsiones; en su etapa más avanzada, se asocia con movimientos anormales y disautonomía. Se reportan dos casos en mujeres de 23 y 12 años. Dada su baja incidencia, se explica el proceso clínico que llevó a su diagnóstico y las opciones de tratamiento empleadas.
Abstract Anti-N-methyl-D-aspartate receptor encephalitis is a neurological syndrome that is more common in young women and is often associated with ovarian teratoma. It is characterized by acute general unspecific symptoms that evolve to neurological deterioration, psychosis and seizures. In its more advanced stage it is associated with abnormal movements and dysautonomia. We report two cases in women of 23 and 12 years of age. Given its low incidence, we present the clinical exercise that led to their diagnoses and the treatment options employed.
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Female , Humans , Ovarian Neoplasms/complications , Seizures/complications , Seizures/pathology , Teratoma/complications , Receptors, N-Methyl-D-Aspartate/immunology , Encephalitis/therapy , Hashimoto Disease , Anti-N-Methyl-D-Aspartate Receptor Encephalitis/complications , Ovarian Neoplasms/immunology , Teratoma/immunology , Anti-N-Methyl-D-Aspartate Receptor Encephalitis/immunology , Antibodies/immunologyABSTRACT
Objective@#To investigate the influence of occupational aluminum exposure on cognitive function and glutamate receptor protein expression in peripheral blood lymphocytes in workers and the possibility of glutamate receptor being used as a biomarker for cognitive impairment in aluminum workers.@*Methods@#From October to December, 2014, cluster sampling was performed to select 121 workers in aluminum electrolysis workshop as exposure group and 231 workers in thermoelectric workshop and logistics department as control group. Mini-Mental State Examination, clock drawing test, digit span test (DST) , verbal fluency test (VFT) , and Fuld Object-Memory (FOM) Evaluation were used to analyze cognitive function. Graphite furnace atomic absorption spectrophotometry was used to measure plasma aluminum level as an exposure indicator. Enzyme-linked immunosorbent assay was used to measure the content of glutamate receptor proteins in peripheral blood lymphocytes, including the subunits of N-methyl-D-aspartate receptor NR1, NR2A, and NR2B and metabotropic glutamate receptor 1 (mGluR1) . The correlation between cognitive function indices and the content of glutamate receptor proteins was analyzed.@*Results@#There was no significant difference in plasma aluminum level between the control group and the exposure group (132.52±80.40 μg/L vs 182.88±72.32 μg/L, P>0.05) . According to the plasma aluminum level, the study subjects were divided into control group and low-, medium-, and high-level plasma aluminum groups, and there were significant differences in plasma aluminum level between these groups (all P<0.01) . The high-level plasma aluminum group had a significantly lower memory ability score than the control group and the low- and medium-level plasma aluminum groups (all P<0.05) . The high-level plasma aluminum group had lower DST and digital span forward (DSF) scores than the control group and the low-and medium-level plasma aluminum groups. The low-, medium-, and high-level plasma aluminum groups had lower digital span backward (DSB) scores than the control group. The medium-and high-level plasma aluminum groups had lower VFT scores than the control group and the low-level plasma aluminum group. The high-level plasma aluminum group had significantly lower expression of NR1 and NR2A proteins than the control group and the low-and medium-level plasma aluminum groups, and the medium- and high-level plasma aluminum groups had significantly higher expression of mGluR1 protein than the control group and the low-level plasma aluminum group (all P<0.05) . The expression of NR1 and NR2A proteins was negatively correlated with plasma aluminum level (r=-0.475 and -0.692, both P<0.05) , andthe expression of mGluR1 protein was positively correlated with plasma aluminum level (r=0.756, P<0.05) . The expression of NR1 protein was positively correlated with DSF, DSB, DST, and VFT scores (rs=0.213, 0.249, 0.271, and 0.228, all P<0.05) , and the expression of NR2A protein was positively correlated with VFT score (rs=0.206, P<0.05) .@*Conclusion@#Occupational aluminum exposure may affect workers’ memory function, and the expression of NR1 and NR2A in peripheral blood lymphocytes is correlated with cognitive function indices and can be used as biomarkers for cognitive impairment in aluminum workers.
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Objective To explore the association between impulsively aggressive behavior and rs6922753 single nucleotide polymorphism of glutamate receptor 6 (GluR6) gene in Xinjiang Uygur and Han patients with bipolar disorder.Methods The techniques of polymerase chain reaction (PCR) and DNA sequencing technique were conducted to detect rs6922753 single nucleotide polymorphism of GluR6 gene in 240 patients with bipolar disorder.The association between the polymorphisms and impulsively aggressive behavior was analyzed with SPSS 17.0 software.Results No statistical difference was observed between the impulsively aggressive behavior group and the no impulsively aggressive behavior group of Xinjiang Han and Uygur patients with bipolar disorder in the genotype and allele frequencies for the investigated rs6922753 polymorphisms (P ＞ 0.05).Conclusions No association was found between the impulsively aggressive behavior and rs6922753 single nucleotide polymorphism of GluR6 gene in Xinjiang Uygur and Han patients with bipolar disorder.
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Objective To evaluate the effect of electroconvulsive therapy (ECT) on the expression of phosphorylated glutamate receptor 1 (p-GluR1) and Ca2+/calmodulin-dependent protein kinase Ⅱ α (p-CaMK Ⅱ α) under small dose ketamine combined with propofol anesthesia in the depressed rats.Methods Forty healthy adult male Sprague-Dawley rats,weighing 200-250 g,aged 2-3 months,were used in this study.Mental depression was induced by exposing the animals to chronic unpredictable mild stress (CUMS).Forty mentally depressed rats were divided randomly into 5 groups (n =8 each) using a random number table:M0-4 groups.Propofol 80 mg/kg and ketamine 10 mg/kg were injected intraperitoneally in M0-4 groups.After disappearance of righting reflex,M1-4 groups received ECT of 60,120,180 and 240 mC once a day for 7 consecutive days,respectively,by means of a current (frequency 50 Hz,sine-wave,pulse width 0.7 ms,1-s duration) delivered via ear-clip electrodes,while group M0 received ECT of no quantity of electric charge via ear-clip electrodes.Before CUMS,at 1 day after CUMS and at 1 day after ECT,sucrose preference test was applied to evaluate the depressive behavior.The sucrose preference percentage (SPP) was calculated.At 4 days after CUMS and 4 days after ECT,the learning and memory function was assessed using Morris water maze test.The rats were then sacrificed,and hippocampi were isolated to detect the expression of GluR1,p-GluRl,CaMK Ⅱ α and p-CaMK Ⅱ α by Western blot.Results The SPP was significantly lower after CUMS than before CUMS in M0-4 groups (P＜0.05).Compared with that after CUMS,the SPP was significantly increased,the escape latency was shortened,and the space exploration time was prolonged after ECT in M1-4 groups (P＜0.05).There was no significant difference in SPP after ECT between M1-4 groups (P＞0.05).Compared with group M0,the SPP was significantly increased,and the expression of pGluR1 and p-CaMK Ⅱ α was up-regulated in M1-4groups (P＜0.05).Compared with group M2,the escape latency was significantly prolonged,the space exploration time was shortened,and the expression of pGluR1 and p-CaMK Ⅱ α was down-regulated after ECT in the other groups (P＜0.05).There was no significant difference in GluR1 and CaMK Ⅱ α expression after ECT between the five groups (P＞ 0.05).Conclusion ECT can induce cognitive decline when applied for anti-depression under small dose ketamine combined with propofol anesthesia,and the mechanism is related to increased phosphorylation of GluR1 and CaMK Ⅱ α expression in rats.
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Objective To evaluate regulatory effects of glutamate receptor antagonists on the proliferation and migration of WM451LU malignant melanoma cells, and to explore their related mechanisms. Methods WM451LU cells at exponential growth phase were classified into 3 groups to be treated with the glutamate receptor antagonist MK?801 at 100μmol/L(MK?801 group), the glutamate receptor antagonist CPCCOEt at 10μmol/L(CPCCOEt group), or culture medium(control group). After 24?hour treatment, methyl thiazolyl tetrazolium(MTT)assay was performed to determine cell proliferation rates, scratch assay to evaluate the migration activity of cells, and Western?blot analysis to measure expression levels of proliferating cell nuclear antigen (PCNA), protein kinase Cα(PKCα) both on cell membrane and in cytoplasm, and phosphorylated mitogen?activated protein kinase(p?MAPK). Results After 24?hour treatment, cell proliferation rates were significantly decreased in the MK?801 group and CPCCOEt group compared with the control group(63%± 3.1%and 60%± 2.4%vs. 100%± 1.1%, both P<0.05). The scratch assay showed that cell?free zones in the control group gradually narrowed over time, and the scratch wound tended to close. However, the cell?free zones in the MK?801 group and CPCCOEt group narrowed more slowly compared with the control group, and were still wide after 24?hour culture with no obvious closure of the scratch. The MK?801 group and CPCCOEt group both showed significantly decreased expressions of PCNA(77.0% ± 5.4% and 72.0% ± 4.2% respectively), PKCα on the cell membrane(0.12 ± 0.02 and 0.14 ± 0.02 respectively), and p?MAPK(0.48 ± 0.03 and 0.36 ± 0.04 respectively) compared with the control group(PCNA:100.0%± 1.3%;PKCα:0.38 ± 0.01;p?MAPK:1.00 ± 0.02;all P<0.05).Conclusion In vitro suppression of glutamate receptors can inhibit the proliferation and migration of WM451LU cells, likely through the mediation of the PKCα?MAPK signaling pathway.
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Objective To investigate the association between glutamate receptor-6 (GIuR6/GRIK2) gene polymorphism and domestic violence in Xinjiang Uygur population on alcoholics.Methods The methods of polymerase chain reaction (PCR) and DNA sequencing technique were conducted to detect rs6922753 and rs2227283 single nucleotide polymorphism of GLUR6 gene in a 104 domestic violence perpetrators on alcoholics and 80 non-domestic violence perpetrators on alcoholics.The association between the polymorphisms and violent behavior was analyzed with SPSS 17.0.Results The frequency of allele (x2 =4.935) and genotype (x2 =7.622) of rs6922753 polymorphisms in the domestic violence group were statistically different from those in the non-domestic violence group (P ＜ 0.05),there was no significant difference between two groups in allele frequencies and genotype in rs2227283 site (P ＞ 0.05).Conclusions GIuR6 gene polymorphism may be associated with domestic violence in Xinjiang Uygur population on alcoholics.
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BACKGROUND/AIMS: Digestion of dietary protein elevates intraluminal concentrations of glutamate in the small intestine, some of which gain access to the enteric nervous system (ENS). Glutamate, in the central nervous system (CNS), is an excitatory neurotransmitter. A dogma that glutamatergic neurophysiology in the ENS recapitulates CNS glutamatergic function persists. We reassessed the premise that glutamatergic signaling in the ENS recapitulates its neurotransmitter role in the CNS. METHODS: Pharmacological analysis of actions of receptor agonists and antagonists in concert with immunohistochemical localization of glutamate transporters and receptors was used. Analysis focused on intracellularly-recorded electrical and synaptic behavior of ENS neurons, on stimulation of mucosal secretion by secretomotor neurons in the submucosal plexus and on muscle contractile behavior mediated by musculomotor neurons in the myenteric plexus. RESULTS: Immunoreactivity for glutamate was expressed in ENS neurons. ENS neurons expressed immunoreactivity for the EAAC-1 glutamate transporter. Neither L-glutamate nor glutamatergic receptor agonists had excitatory actions on ENS neurons. Metabotropic glutamatergic receptor agonists did not directly stimulate neurogenic mucosal chloride secretion. Neither L-glutamate nor the metabotropic glutamatergic receptor agonist, aminocyclopentane-1,3-dicarboxylic acid (ACPD), changed the mean amplitude of spontaneously occurring contractions in circular or longitudinal strips of intestinal wall from either guinea pig or human small intestinal preparations. CONCLUSIONS: Early discoveries, for excitatory glutamatergic neurotransmission in the CNS, inspired enthusiasm that investigation in the ENS would yield discoveries recapitulating the CNS glutamatergic story. We found this not to be the case.
Subject(s)
Animals , Humans , Amino Acid Transport System X-AG , Central Nervous System , Dietary Proteins , Digestion , Enteric Nervous System , Glutamic Acid , Guinea Pigs , Intestine, Small , Intestines , Muscles , Myenteric Plexus , Neurons , Neurophysiology , Neurotransmitter Agents , Proteolysis , Receptors, Glutamate , Submucous Plexus , Synaptic TransmissionABSTRACT
Objective To evaluate the role of the expression of protein kinase Cγ and Cα in spinal dorsal horn in the metabotropic glutamate receptor subtype 5 (mGluR5)'s participation in the development of morphine tolerance in rats. Methods Thirty-two male SD rats in which the intrathecal (IT) catheter was successfully placed were randomly divided into 4 groups (n = 8 each): control group (group C), morphine tolerance group (group M), antisense oligodeoxynucleotide (ODN) plus morphine group (group ANT) and mismatch ODN plus morphine group (group MIS). Rats in group M received 0.9% normal saline (NS) 5 μl twice a day for 8 days, and IT morphine 15 μg was injected simultaneously at 6, 7 and 8 days twice a day. Rats in group ANT and MIS received IT antisense and mismatch ODN 30 nmol (in 0.9% NS 5 μl) twice a day for 8 days respectively and IT morphine 15 μg was injected simultaneously at 6, 7 and 8 days twice a day. Rats in group C received NS instead twice a day for 8 days. Paw-withdrawl threshold (PWT) to thermal and mechanical stimulation was measured at 6, 7 and 8 days after ODN injection (T1-3). The animals were killed on 9th day (T4) and the lumbar segment of the spinal cord was removed for determination of the expression of mGluR5, PKCα and PKCγ mRNA (by RT-PCR), PKCαand PKCγ ( by Western blot). Results PWT to thermal and mechanical stimulation was significantly higher at T1.2in group M and MIS and at T1.3 in group ANT, the expression of mGluR5 mRNA, PKCα and PKCγ was significantly higher at T4 in group M and MIS, and mGluR5 mRNA expression was significantly lower at T4 in group ANT than in group C ( P ＜ 0.05). PWT to thermal and mechanical stimulation was significantly higher at T2.3, while the expression of mGluR5 mRNA, PKCα and PKCγ lower at T4 in group ANT than in group M ( P ＜ 0.05). Conclusion The expression of protein kinase C in spinal dorsal horn plays an important role in the mGluR5's participation in the development of morphine tolerance in rats.
ABSTRACT
AIM: To explore the role of NO/ inducible nitric oxide synthase (iNOS) in the metabotromi glutamate receptor 2/3C (mGluR2/3) mediated-brain ischemic tolerance induced by cerebral ischemic preconditioning (CIP), and to observe the influences of α-methyl- (4-tetrazolyl- phenyl) glycine (MTPG), an antagonist of mGluR2/3, on the expression of iNOS during the induction of brain ischemic tolerance. METHODS: Thirty-six Sprague-Dawley rats were subjected to four vessel occluding global brain ischemic model. Thionin staining and immunohistochemistry were used for neuropathological evaluation and assay of iNOS expression in the hippocampal CA1 subregion of the rats. RESULTS: In the sham group, weak expression of iNOS was detected. The expression of iNOS in the CIP and CIP+ischemic insult groups were increased significantly compared with that in the sham group. Administration of MTPG via lateral cerebral ventricle 20 min before CIP blocked the up-regulation of iNOS induced by CIP, but had no influence on the pyramidal neuron survival. However, in the MTPG+CIP+ischemic insult group, the expression of iNOS was extremely intensive compared to that in CIP and MTPG+CIP groups. Importantly, this up-regulation was accompanied with obvious delayed neuronal death. CONCLUSION: NO/iNOS pathway plays an important role in the process of mGluR2/3 mediated-brain ischemic tolerance induced by CIP.
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Objective To investigate the effects of glutamate receptor signaling on melanoma cell dendrite morphology and cytoskeleton protein. Methods A metastatic human malignant melanoma cell line WM451LU was cultured and transfected by recombinant adenovirus vector carrying a cDNA encoding microtubule-associated protein 2a (MAP2a). MK-801, an antagonist of N-methyl-D-aspartate receptor (NMDAR), and CPCCOEt, an antagonist of metabotropie glutamate receptor 1 (mGluR1), were used to treat transfected or untrausfeeted WM451LU cells. Confocal microscopy and three dimensional atomic force microscopy were used to assess subcellular location of NMDAR2A, mGluR1 and MAP2a as well as the dis-tribution of α-tubulin in and dendrite morphology of WM451LU cells. The proliferation of WM451LU cells was estimated by cell survival growth curve. Results Confocal laser microscopy revealed that NMDAR2A, mGluRl and MAP2a were mainly co-localized in melanoma cell dendrites. Both MK-801 and CPCCOEt increased the density of microtubules in cell dendrites and dendritic branching of WM451LU cells, and both effects of MK-801 and CPCCOEt were enhanced by the expression of MAP2a. Furthermore, the proliferation of WM451LU cells was significantly inhibited by MK-801 of 100 μmol/L and CPCCOEt of 10 μmol/L. Conclusions In melanoma cells, glutamate receptors may participate in the development of dendrites, and anta- gonists of glutamate receptors could inhibit the proliferation of melanoma cells.
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Neuronal migration disorders (NMDs) constitute the main pathologic substrate of medically intractable epilepsy in human. This study is designed to investigate the changes in expression of glutamate receptor subtypes on radiation-induced NMD in rats. The lesion was produced by intrauterine irradiation (240 cGy) on E17 rats, and then 10 weeks old rats were used for the study. The pathologic and immunohistochemical findings for glutamate receptor subunit proteins on NMD cortex were correlated with development of behavioral seizures and EEG abnormality. Spontaneous seizures uncommonly occurred in NMD rats (5%); however, clinical stages of seizures were significantly increased in NMD rats by an administration of kainic acid. Brains taken from irradiated rats revealed gross and histopathologic features of NMD. Focal cortical dysplasia was identified by histopathology and immunohistochemistry with neurofilament protein (NF-M/H). Significantly strong NR1 and NR2A/B immunoreactivities were demonstrated in cytomegalic and heterotopic neurons of NMD rats. The results of the present study indicate that epileptogenesis of NMD might be caused by upregulation of glutamate receptor expression in dysplastic neurons of the rat cerebral cortex with NMDs.