Water-soluble lipopolymer delivery of N-methyl-D-aspartic acid receptor 2B siRNA relieves chronic neuropathic pain in rats

Spinal dorsal horn N-Methyl-D-aspartic acid receptor 2B （NR2B） overexpression plays an important role in the production and maintenance of neuropathic pain. Because small interfering RNA （siRNA） can inhibit NR2B expression, siRNA may provide a novel approach to treat neuropathic pain and possibly nerve injury. However, an efficient and safe vector for NR2B siRNA has not been discovered. This study shows that a water soluble lipopolymer （WSLP） comprised of low molecular weight polyethyleneimine （PEI） and cholesterol can deliver siRNA targeting NR2B for the treatment of neuropathic pain. Results show that intrathecal injection of WSLP/siRNA complexes for 3 days inhibit NR2B gene expression with reductions in mRNA and protein levels by 59% and 54%, respectively, compared with control rats （P 〈 0.01）. Injection of WSLP complexed with scrambled siRNA, or PEI with siRNA did not show this inhibitory effect. Moreover, injection of WSLP/siRNA complexes significantly relieved neuropathic pain at 3, 7, 12, and 21 days, while injection of WSLP with scrambled siRNA or PEI with siRNA did not. These results demonstrate that WSLP can efficiently deliver siRNA targeting NR2B in vivo and relieve neuropathic pain.

Effect of Chronic Noise Exposure on Expression of N-Methyl-D-Aspartic Acid Receptor 2B and Tau Phosphorylation in Hippocampus of Rats

Objective To study the effect of chronic noise exposure on expression of N-methyI-D-aspartic acid receptor 2B （NR2B） and tau phosphorylation in hippocampus of rats. Methods Twenty-four male SD rats were divided in control group and chronic noise exposure group. NR2B expression and tau phosphorylation in hippocampus of rats were detected after chronic noise exposure （100 dB SPL white noise, 4 h/dx30d） and their mechanisms underlying neuronal apoptosis in hippocampus of rats with TUNEL staining. Results The NR2B expression decreased significantly after chronic noise exposure which resulted in tau hyperphosphorylation and neural apoptosis in hippocampus of rats. Immunohistochemistry showed that the tau hyperphosphorylation was most prominent in dentate gyrus （DG） and CA1 region of rat hippocampus. Conclusion The abnormality of neurotransmitter system, especially Glu and NR2B containing NMDA receptor, and tau hyperphosphorylation in hippocampus of rats, may play a role in chronic noise-induced neural apoptosis and cognition impairment.

Propofol effectively inhibits lithium-pilocarpine-induced status epilepticus in rats via downregulation of N-methyl-D-aspartate receptor 2B subunit expression

Status epilepticus was induced via intraperitoneal injection of lithium-pilocarpine.The inhibitory effects of propofol on status epilepticus in rats were judged based on observation of behavior,electroencephalography and 24-hour survival rate.Propofol（12.5-100 mg/kg） improved status epilepticus in a dose-dependent manner,and significantly reduced the number of deaths within 24 hours of lithium-pilocarpine injection.Western blot results showed that,24 hours after induction of status epilepticus,the levels of N-methyl-D-aspartate receptor 2A and 2B subunits were significantly increased in rat cerebral cortex and hippocampus.Propofol at 50 mg/kg significantly suppressed the increase in N-methyl-D-aspartate receptor 2B subunit levels,but not the increase in N-methyl-D-aspartate receptor 2A subunit levels.The results suggest that propofol can effectively inhibit status epilepticus induced by lithium-pilocarpine.This effect may be associated with downregulation of N-methyl-D-aspartate receptor 2B subunit expression after seizures.

Inhibition of N-methyl-D-aspartate-activated Current by Bis(7)-tacrine in HEK-293 Cells Expressing NR1/NR2A or NR1/NR2B Receptors

In normal rat forebrain, the NR1/NR2A and NR1/NR2B dimmers are the main constitutional forms of NMDA receptors. The present study was carried out to determine the functional properties of the heteromeric NMDA receptor subunits and their inhibition by bis(7)-tacrine (B7T). Rat NR1, NR2A and NR2B cDNAs were transfected into human embryonic kidney 293 cells (HEK-293).The inhibition of NMDA-activated currents by B7T was detected in HEK-293 cell expressing NR1/NR2A or NR1/NR2B receptors by using whole-cell patch-clamp techniques. The results showed that in HEK-293 cells expressing NR1/NR2A receptor, 1μmol/L B7T inhibited 30μmol/L NMDA- and 1000μmol/L NMDA-activated steady-state currents by 46% and 40%, respectively (P>0.05; n=5), suggesting that the inhibition of B7T on NR1/NR2A receptor doesn’t depend on NMDA concentration, which is consistent with a non-competitive mechanism of inhibition. But for the NR1/NR2B receptor, 1μmol/L B7T inhibited 30μmol/L NMDA- and 1000 μmol/L NMDA-activated steady-state currents by 61% and 13%, re-spectively (P<0.05; n=6), showing that B7T appears to be competitive with NMDA. In addition, simultaneous application of 1μmol/L B7T and 1000μmol/L NMDA produced a moderate inhibition of peak NMDA-activated current, followed by a gradual decline of the current to a steady state. However, the gradual onset of inhibition produced by B7T applied simultaneously with NMDA was eliminated when B7T was given 5s before NMDA. These results suggested that B7T inhibition of NMDA current mediated by NR1/NR2B receptor was slow onset, and it did not depend on the presence of the agonist. With holding potentials ranging from -50 to +50 mV, the B7T inhibition rate of NMDA currents didn’t change significantly, and neither did the reversal potential. We are led to conclude that the NR1/NR2B recombinant receptor can serve as a very useful model for studying the molecular mechanism of NMDA receptor inhibition by B7T.

神经病理性疼痛大鼠脊髓背角小胶质细胞和γ-氨基丁酸B型受体2的表达

目的探讨小胶质细胞和γ-氨基丁酸B型受体2(GABABR2)在神经病理性疼痛中的作用及其可能的机制。方法选择健康雄性Sprague-Dawley大鼠48只,随机分入4组,每组12只:假手术+鞘内注射0.9%氯化钠溶液组(假手术对照组),假手术+鞘内注射米诺环素组(假手术药物组),手术+鞘内注射0.9%氯化钠溶液组(手术对照组),手术+鞘内注射米诺环素组(手术药物组)。手术对照组和手术药物组大鼠结扎L5的神经根建立神经病理性疼痛模型,假手术对照组和假手术药物组大鼠仅暴露但不结扎L5的神经根。4组大鼠按组别每天2次鞘内注射米诺环素或0.9%氯化钠溶液,通过测定大鼠各时间点的50%机械缩足阈值评价大鼠的机械痛敏,并在术后8d采用免疫荧光方法测定大鼠脊髓背角小胶质细胞和背角神经元GABABR2的表达情况。结果手术对照组和手术药物组大鼠术后1d神经根结扎侧即表现为机械异常性疼痛,术后1、3、8、16d的50%机械缩足阈值均显著低于同组术前(P值均<0.01)。手术对照组术后1、3、8、16d的50%机械缩足阈值均显著低于假手术对照组同时间点(P值均<0.01)。手术药物组术后1、3、8、16d的50%机械缩足阈值虽显著低于假手术药物组同时间点(P值均<0.05),但显著高于手术对照组同时间点(P值均<0.05)。小胶质细胞主要分布在脊髓背角浅层Ⅰ至Ⅳ层。术后8d,手术对照组大鼠术侧脊髓背角小胶质细胞平均光密度值显著高于同组健侧和假手术对照组术侧(P值均<0.01);手术药物组大鼠术侧脊髓背角小胶质细胞平均光密度值虽显著高于假手术药物组术侧和同组健侧(P值均<0.01),但显著低于手术对照组术侧(P<0.01)。GABABR2受体在脊髓背角的各层都有表达,以脊髓背角Ⅰ至Ⅲ层表达最多,主要位于神经元包膜和细胞质中。术后8d,手术对照组大鼠术侧脊髓背角GABABR2免疫阳性产物平均光密度值显著低于同组健侧和假手术对照组术侧(P值均<0.01);手术药物组大鼠术侧脊髓背角GABABR2免疫阳性产物平均光密度值虽显著低于假手术药物组术侧和同组健侧(P值均<0.01),但显著高于手术对照组术侧(P<0.05)。结论鞘内注射小胶质细胞特异抑制剂米诺环素可以明显抑制脊神经结扎大鼠的机械痛敏,并引起脊髓背角神经元上GABAR2的表达变化,表明小胶质细胞和GABABR2均参与神经病理性疼痛的形成和发展,并提示GABABR2可能作为小胶质细胞的下游机制参与了神经病理性疼痛的发生、发展过程。

丹酚酸B通过PPARα抑制2型糖尿病小鼠心肌肥厚

目的研究丹酚酸B(Sal B)对2型糖尿病(T2DM)模型小鼠心肌肥厚的影响,并从过氧化物酶体增殖物激活受体α(PPARα)角度探讨其机制。方法采用高脂饮食喂养4周联合链脲佐菌素(streptozotocin,STZ)单次腹腔注射法建立T2DM小鼠模型,实验小鼠分为对照组(control)、T2DM模型组、T2DM+Sal B组、Sal B组,上述条件继续饲养8周。检测各组小鼠心脏重量、胫骨长度、心肌细胞横截面积及心脏PPARα表达水平。体外采用高糖联合高胰岛素(HGI)诱导乳大鼠心肌细胞肥大,观察Sal B及PPARα抑制剂MK886对心肌细胞表面积、~3H-亮氨酸参入率、~3H-D-葡萄糖参入率及PPARα表达的影响。结果Sal B能降低T2DM模型小鼠心脏重量/胫骨长度比例、心肌细胞横截面积,并上调心脏组织PPARα表达水平。体外Sal B(10-100μmol·L^(-1))能浓度依赖性地抑制HGI诱导的心肌细胞表面积、亮氨酸参入率增加及~3H-D-葡萄糖参入率、PPARα的下调,但上述效应能够被MK886所消除。结论Sal B能够抑制T2DM模型小鼠的心肌肥厚,其机制与上调PPARα表达有关。

阿魏酸对2型糖尿病小鼠心肌损伤的影响

目的探讨阿魏酸对2型糖尿病db/db小鼠心肌损伤的保护作用及其作用机制。方法将适应性饲养后筛选出的20只2型糖尿病db/db小鼠随机均分为模型组和阿魏酸组,另随机抽取10只正常db/m小鼠作为对照组。对照组和模型组灌胃蒸馏水,阿魏酸组灌胃阿魏酸(30mg/kg),每天灌胃1次,连续给药8周后处死,取血清检测血糖(BG)、肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)和糖基化终末代谢产物(A GEs)含量。HE和Masson染色观察心脏组织形态学改变;实时荧光定量PCR(Q-PCR)检测Toll样受体4(TLR-4)、核转录因子-B(NF-B)、核苷酸结合寡聚化结构域样受体3(NALP3)mRNA表达情况;免疫组化染色和Westernblot法检测TLR-4、NF-B、NALP3蛋白表达情况。结果模型组小鼠体质量、心脏质量和心脏质量指数较对照组明显增高,阿魏酸干预后,体质量、心脏质量和心脏质量指数较模型组明显降低(均P<0.05),模型组小鼠心肌细胞肿胀肥大,可见明显纤维增生,阿魏酸干预后心肌细胞肿胀情况和纤维增生情况明显减轻;模型组血清BG、CK、CK-MB、AGEs表达水平明显升高,阿魏酸干预后,血清BG、CK、CK-MB、AGEs表达水平较模型组明显降低(均P<0.05);模型组TLR-4、NF-B、NALP3mRNA和蛋白表达水平均明显高于对照组,阿魏酸干预后TLR-4、NF-B、NALP3mRNA和蛋白表达水平明显降低(均P<0.05)。结论阿魏酸具有改善2型糖尿病小鼠血糖水平,减轻心肌细胞损伤及心肌纤维化的作用,其机制可能与抑制TLR-4/NF-B信号通路,抑制炎症反应有关。

γ-氨基丁酸B型受体活性对慢性应激大鼠下丘脑神经元超微结构的影响

目的:观察γ-氨基丁酸B型受体(GABA_(B)R)活性对慢性应激大鼠下丘脑神经元超微结构的影响。方法:Wistar大鼠60只,分为对照组(control)、应激组(stress)、应激结合2-羟基萨氯酚(2-OH-saclofen)给药组(stress+2-OH-saclofen)、应激结合氯苯氨丁酸(baclofen)给药组(stress+baclofen)。采用间歇低频电击大鼠足底并联合噪声的方式建立应激大鼠模型,同时2-羟基萨氯酚(100μg/kg)或氯苯氨丁酸(0.04 g/kg)分别经大鼠腹腔注射。应激40 d后,对处于不同应激阶段的大鼠进行取材。在透射电镜下观察下丘脑神经元超微结构的变化;用高效液相色谱法(HPLC)检测大鼠下丘脑内NE和DA含量的变化。结果:在透射电镜下观察发现,单纯应激组、应激结合氯苯氨丁酸给药组与正常对照组相比较,大鼠下丘脑神经元的超微结构出现不同程度的退行性变化;相反应激结合2-羟基萨氯酚给药组下丘脑神经元超微结构则未出现退行性改变。用(HPLC)检测大鼠下丘脑内NE和DA含量发现,与正常对照组相比,单纯应激组NE含量明显升高但呈现下降趋势,DA含量则呈上升趋势(P<0.05)。应激结合氯苯氨丁酸给药组NE和DA含量呈上升趋势(P<0.05)。应激结合2-羟基萨氯酚给药组NE和DA含量却接近正常水平。结论:GABA B受体抑制剂2-羟基萨氯酚对慢性应激大鼠下丘脑神经元有保护作用,而GABA B受体激动剂氯苯氨丁酸则有损害作用。

Mechanisms responsible for the inhibitory effects of epothilone B on scar formation after spinal cord injury

Scar formation after spinal cord injury is regarded as an obstacle to axonal regeneration and functional recovery.Epothilone B provides moderate microtubule stabilization and is mainly used for anti-tumor therapy.It also reduces scar tissue formation and promotes axonal regeneration after spinal cord injury.The aim of the present study was to investigate the effect and mechanism of the microtubule-stabilizing reagent epothilone B in decreasing fibrotic scarring through its action on pericytes after spinal cord injury.A rat model of spinal cord injury was established via dorsal complete transection at the T10 vertebra.The rats received an intraperitoneal injection of epothilone B（0.75 mg/kg） at 1 and 15 days post-injury in the epothilone B group or normal saline in the vehicle group.Neuron-glial antigen 2,platelet-derived growth factor receptor β,and fibronectin protein expression were dramatically lower in the epothilone B group than in the vehicle group,but β-tubulin protein expression was greater.Glial fibrillary acidic protein at the injury site was not affected by epothilone B treatment.The Basso,Beattie,and Bresnahan locomotor scores were significantly higher in the epothilone B group than in the vehicle group.The results of this study demonstrated that epothilone B reduced the number of pericytes,inhibited extracellular matrix formation,and suppressed scar formation after spinal cord injury.

Protective effect of tetrahydroxy stilbene glucoside on learning and memory by regulating synaptic plasticity

Damage to synaptic plasticity induced by neurotoxicity of amyloid-beta is regarded to be one of the pathological mechanisms of learning and memory disabilities in Alzheimer＇s disease patients. This study assumed that the damage of amyloid-beta to learning and memory abilities was strongly associated with the changes in the Fyn/N-methyl-D-aspartate receptor 2B （NR2B） expression. An APP695V7171 transgenic mouse model of Alzheimer＇s disease was used and treatment with tetrahydroxy-stilbene glucoside was administered intragas- trically. Results showed that intragastric administration of tetrahydroxy-stilbene glucoside improved the learning and memory abilities of the transgenic mice through increasing NR2B receptors and Fyn expression. It also reversed parameters for synaptic interface structure of gray type I. These findings indicate that tetrahydroxy stilbene glucoside has protective effects on the brain, and has prospects for its clinical application to improve the learning and memory abilities and treat Alzheimer＇s disease.

Protective effects of Bushen Tiansui decoction on hippocampal synapses in a rat model of Alzheimer's disease

Bushen Tiansui decoction is composed of six traditional Chinese medicines：Herba Epimedii,Radix Polygoni multiflori,Plastrum testudinis,Fossilia Ossis Mastodi,Radix Polygalae,and Rhizoma Acorus tatarinowii.Because Bushen Tiansui decoction is effective against amyloid beta（Aβ） toxicity,we hypothesized that it would reduce hippocampal synaptic damage and improve cognitive function in Alzheimer＇s disease.To test this hypothesis,we used a previously established animal model of Alzheimer＇s disease,that is,microinjection of aggregated Aβ25–35 into the bilateral brain ventricles of Sprague-Dawley rats.We found that long-term（28 days） oral administration of Bushen Tiansui decoction（0.563,1.688,and 3.375 g/m L;4 m L/day） prevented synaptic loss in the hippocampus and increased the expression levels of synaptic proteins,including postsynaptic density protein 95,the N-methyl-D-aspartate receptor 2 B subunit,and Shank1.These results suggested that Bushen Tiansui decoction can protect synapses by maintaining the expression of these synaptic proteins.Bushen Tiansui decoction also ameliorated measures reflecting spatial learning and memory deficits that were observed in the Morris water maze（i.e.,increased the number of platform crossings and the amount of time spent in the target quadrant and decreased escape latency） following intraventricular injections of aggregated Aβ25–35 compared with those measures in untreated Aβ_（25–35）-injected rats.Overall,these results provided evidence that further studies on the prevention and treatment of dementia with this traditional Chinese medicine are warranted.

IRS-1/PI3K/Akt2信号通路调控miR-139-5p对2型糖尿病大鼠的干预效果

目的分析基于胰岛素受体底物1(IRS-1)/磷脂酰肌醇3激酶(PI3K)/蛋白激酶B(Akt2)信号通路调控微小核糖核酸139-5p(miR-139-5p)对2型糖尿病大鼠的干预效果。方法选取52只雄性SPF级Wistar大鼠,12只大鼠作为对照组,另外40只建立2型糖尿病模型,将建模成功36只大鼠采用随机数字表法分为模型组、沉默组、过表达组,每组各12只。对照组、模型组大鼠注射同剂量0.9%氯化钠溶液,沉默组大鼠尾静脉注射10μL miR-139-5p沉默慢病毒悬液,过表达组大鼠尾静脉注射10μL miR-139-5p过表达慢病毒悬液,于miR-139-5p转染后,对各组大鼠毛发光泽度、活动、形态等一般情况进行观察。对各组大鼠miR-139-5p、IRS-1、PI3K、Akt2表达量、血糖相关指标[胰岛素抵抗指数(HOMA-IR)、空腹胰岛素、空腹血糖、胰岛β细胞功能指数(HOMA-β)]、炎症因子[白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)]水平、血脂变化水平、IRS-1/PI3K/Akt2信号通路蛋白表达量进行检测。结果与对照组相比,模型组、沉默组、过表达组miR-139-5p表达量、HOMA-β、IRS-1、PI3K、Akt2 mRNA表达量、IRS-1、磷酸化IRS-1(p-IRS-1)、PI3K、磷酸化PI3K(p-PI3K)、Akt2、磷酸化Akt2(p-Akt2)表达量均降低,HOMA-IR、空腹胰岛素、空腹血糖、IL-6、TNF-α、总胆固醇、甘油三酯均升高,差异均有统计学意义(P<0.05);与模型组相比,沉默组、过表达组miR-139-5p表达量、HOMA-IR、空腹胰岛素、空腹血糖、IL-6、TNF-α、总胆固醇、甘油三酯均降低,HOMA-β、IRS-1、PI3K、Akt2 mRNA表达量、IRS-1、p-IRS-1、PI3K、p-PI3K、Akt2、p-Akt2表达量均升高,差异均有统计学意义(P<0.05);与沉默组相比,过表达组miR-139-5p相对表达量、HOMA-IR、空腹胰岛素、空腹血糖、IL-6、TNF-α、总胆固醇、甘油三酯降低,HOMA-β、IRS-1、PI3K、Akt2 mRNA表达量、IRS-1、p-IRS-1、PI3K、p-PI3K、Akt2、p-Akt2表达量升高,差异均有统计学意义(P<0.05)。结论上调miR-139-5p表达,可调节2型糖尿病大鼠体内血糖、血脂水平,其机制可能与IRS-1/PI3K/Akt2信号通路有关。

What is the new target inhibiting the progression of Alzheimer's disease?

To stop the progression of Alzheimer＇s disease in the early stage, it is necessary to identify new therapeutic targets. We examined striatal-enriched phosphatase 61 expression in the brain tissues of 12-month-old APPswe/PSEN1dE9 transgenic mice. Immunohistochemistry showed that striatal-enriched phosphatase 61 protein expression was significantly increased but phosphorylated N-methyl-D-aspartate receptor 2B levels were significantly decreased in the cortex and hippocampus of APPswe/PSEN1dE9 transgenic mice. Western blotting of a cell model of Alzheimer＇s disease consisting of amyloid-beta peptide （1-42）-treated C57BL/6 mouse cortical neurons in vitro showed that valeric acid （AP5）, an N-methyl-D-aspartate receptor antagonist, significantly inhibited amyloidbeta 1-42-induced increased activity of striatal-enriched phosphatase 61. In addition, the phosphorylation of N-methyl-D-aspartate receptor 2B at Tyr1472 was impaired in amyloid-beta 1-42-treated cortical neurons, but knockdown of striatal-enriched phosphatase 61 enhanced the phosphorylation of N-methyl-D-aspartate receptor 2B. Collectively, these findings indicate that striatal-enriched phosphatase 61 can disturb N-methyl-D-aspartate receptor transport and inhibit the progression of learning and study disturbances induced by Alzheimer＇s disease. Thus, striatal-enriched phosphatase 61 may represent a new target for inhibiting the progression of Alzheimer＇s disease.

Baicalein Ameliorates Chronic Stress-Mediated Ovarian Dysfunction by Upregulating the Expression of Gamma-Aminobutyric Acid B2 Receptor

Background:The aim of this study is to assess the effect of baicalein on chronic stress-mediated ovarian dysfunction in a mouse model.Methods:Forty female C57BL/6 mice were randomly divided into four groups as follows:the normal saline group(control,n=10),the daily stress group(daily stress,n=10),the baicalein group(baicalein,n=10),and the daily stress+baicalein group(daily stress+baicalein,n=10).For the daily stress model,we used a restricted stress model.Baicalein(10 mg/kg)was administered by gavage every day,and control mice received normal saline equivalently.Biopsy specimens were harvested after 4 weeks.Measurement of norepinephrine(NE)in serum was performed to assess the psychological stress level of the mice.In addition,histological changes of the uterus and ovaries and the levels of anti-Müllerian hormone(AMH)in serum were assessed to evaluate changes in ovarian function.To detect the underlying mechanisms of the amelioration of baicalein in chronic stress-mediated ovarian dysfunction,immunohistochemical methods,and quantitative real-time polymerase chain reaction were applied to determine the expression of gamma-aminobutyric acid(GABA)receptors.Results:Compared with values in the control group,serum NE concentrations were significantly increased(P<0.001),AMH concentrations were markedly decreased(P<0.01),the thickness of the endometrium was clearly reduced,and the percentage of atretic follicles was significantly increased in the daily stress group(P<0.001),indicating that the chronic stress model was successfully established.In contrast,compared with values in the daily stress group,serum NE concentrations were significantly reduced(P<0.001),AMH concentrations were significantly enhanced(P<0.05),the thickness of the endometrium was clearly increased,and the percentage of atretic follicles was significantly reduced(P<0.001)in the daily stress+baicalein group,indicating that baicalein clearly attenuated the ovarian dysfunction mediated by chronic stress.Moreover,the expression of the GABAB2 receptor in the daily stress group was significantly reduced(P<0.01).In contrast,treatment with baicalein resulted in increased expression of the GABAB2 receptor(P<0.01).Conclusions:Treatment with baicalein ameliorates the enhancing effect of chronic stress on ovarian dysfunction,and the mechanism can be attributed,in part,to the increased expression of the GABAB2 receptor.

慢乙肝患者血清可溶性白细胞介素2受体水平的检测

目的研究慢性乙肝患者的血清可溶性白细胞介素２受体水平与肝脏炎症及损伤的关系。方法采用ＥＬＩＳＡ法测定慢乙肝患者及对照组的血清可溶性白细胞介素２受体，并作统计学分析。同时测定慢乙肝患者谷丙转氨酶，透明质酸，并与血清可溶性白细胞介素２受体水平作相关分析。结果慢乙肝患者的血清可溶性白细胞介素２受体水平明显高于正常人并与谷丙转氨酶，透明质酸呈正相关。结论血清白细胞介素２受体参与慢乙肝的病理生理过程，并反映慢乙肝患者的肝脏炎症及损伤程度。

Activation of glycine site and GluN2B subunit of NMDA receptors is necessary for ERK/CREB signaling cascade in rostral anterior cingulate cortex in rats:Implications for affective pain

Objective The rostral anterior cingulate cortex （rACC） is implicated in processing the emotional component of pain. N-methyl-D-aspartate receptors （NMDARs） are highly expressed in the rACC and mediate painrelated affect by activating a signaling pathway that involves cyclic adenosine monophosphate （cAMP）/protein ki- nase A （PKA） and/or extracellular regulated kinase （ERK）/cAMP-response element-binding protein （CREB）. The present study investigated the contributions of the NMDAR glycine site and GluN2B subunit to the activation of ERK and CREB both in vitro and in vivo in rat rACC. Methods Immunohistochemistry and Western blot analy- sis were used to separately assess the expression of phospho-ERK （pERK） and phospho-CREB （pCREB） in vitro and in vivo. Double immunostaining was also used to determine the colocalization of pERK and pCREB. Results Both bath application of NMDA in brain slices in vitro and intraplantar injection of formalin into the rat hindpaw in vivo induced significant up-regulation of pERK and pCREB in the rACC, which was inhibited by the NMDAR antago- nist DL-2-amino-5-phospho-novaleric acid. Selective blockade of the NMDAR GluN2B subunit and the glycine- binding site, or degradation of endogenous D-serine, a co-agonist for the glycine site, significantly decreased the up- regulation of pERK and pCREB expression in the rACC. Further, the activated ERK predominantly colocalized with CREB. Conclusion Either the glycine site or the GluN2B subunit of NMDARs participates in the phosphorylation of ERK and CREB induced by bath application of NMDA in brain slices or hindpaw injection of 5% formalin in rats, and these might be fundamental molecular mechanisms underlying pain affect.

自身免疫性脑炎患儿的临床分析

目的探讨儿童自身免疫性脑炎(AE)的临床特点、治疗及预后。方法回顾性分析2014年12月至2022年9月贵阳市妇幼保健院收治的39例AE患儿的临床资料。结果39例AE患儿中,13例为抗N-甲基-D-天冬氨酸受体(NMDAR)脑炎、1例为抗γ-氨基丁酸B型受体(GABA BR)脑炎、1例为抗二肽基肽酶样蛋白(DPPX)脑炎、1例为抗接触蛋白相关蛋白2(CASPR2)脑炎、1例为抗CV2脑炎,余22例中17例AE患儿的抗体为阴性,5例未进行抗体检测。AE患儿的主要症状为癫痫发作、认知及行为障碍、意识障碍、运动障碍、睡眠障碍及自主神经功能障碍等,所有患儿均未合并肿瘤。39例中有36例患儿行一线免疫治疗,其中24例好转,12例无效;一线免疫治疗无效的4例患儿行二线免疫治疗,其中2例有效,2例无效。结论AE患儿的临床特点总体与成人患者相似,但儿童不同类型抗体AE有其自身特点,肿瘤发生率低,预后相对成人较好。抗体阴性的AE和可能的AE标准具有重要的临床实践价值。

Neuroprotective effects of tetrandrine against vascular dementia

Tetrandrine is one of the major active ingredients in Menispermaceae Stephania tetrandra S.Moore,and has specific therapeutic effects in ischemic cerebrovascular disease.Its use in vascular dementia has not been studied fully.Here,we investigated whether tetrandrine would improve behavioral and cellular impairments in a two-vessel occlusion rat model of chronic vascular dementia.Eight weeks after model establishment,rats were injected intraperitoneally with 10 or 30 mg/kg tetrandrine every other day for 4 weeks.Behavioral assessment in the Morris water maze showed that model rats had longer escape latencies in training trials,and spent less time swimming in the target quadrant in probe trials,than sham-operated rats.However,rats that had received tetrandrine showed shorter escape latencies and longer target quadrant swimming time than untreated model rats.Hematoxylin-eosin and Nissl staining revealed less neuronal necrosis and pathological damage,and more living cells,in the hippocampus of rats treated with tetrandrine than in untreated model rats.Western blot assay showed that interleukin-1β expression,and phosphorylation of the N-methyl-D-aspartate 2B receptor at tyrosine 1472,were lower in model rats that received tetrandrine than in those that did not.The present findings suggest that tetrandrine may be neuroprotective in chronic vascular dementia by reducing interleukin-1β expression,N-methyl-D-aspartate receptor 2B phosphorylation at tyrosine 1472,and neuronal necrosis.

GluN2A versus GluN2B:twins,but quite different

N-Methyl-D-aspartate receptors（NMDARs） play vital roles in the central nervous system,as they are primary mediators of Ca2＋influx during synaptic activity.The subunits that compose NMDARs share similar topological structures but are distinct in distribution and pharmacological properties,as well as physiological and pathological functions,which make the NMDAR one of the most complex and elusive ionotropic glutamate receptors.In this review,we focus on GluN2A and GluN2B,the primary NMDAR subunits in the cortex and hippocampus,and discuss their differences in developmental expression,brain distribution,trafficking,and functional properties during neuronal activity.

Low-Frequency Electroacupuncture Alleviates Chronic Constrictive Injury-Induced Mechanical Allodynia by Inhibiting NR2B Upregulation in Ipsilateral Spinal Dorsal Horn in Rats

Objective: To study the effects of electroacupuncture(EA) in chronic constrictive injury(CCI) rat model and the expression of N-methyl-D-aspartate receptor type 2B(NR2B) in ipsilateral spinal dorsal horn in rats to explore the analgesic mechanisms of EA. Methods: According to the random number table, totally 180 rats were evenly divided into a sham group, a CCI group, and an EA group. CCI model was conducted with four4–0 chromic gut ligatures loosely ligated around the left sciatic nerve 1 cm above the trifurcation. Rats in the EA group received 2 Hz EA therapy bilaterally at acupoints of Zusanli(ST 36) and Sanyinjiao(SP 6) once daily(30 min/d) for 30 days after surgery. Paw withdrawal thresholds(PWTs) were measured on 0(baseline), 1, 3, 7, 15,30 days after surgery. Rats were sacri?ced on 0, 1, 3, 7, 15 and 30 days after surgery, and the L4–5 segments of spinal cord were removed to detect the expression of NR2B by immunohistochemistry and quantitative polymerase chain reaction. Results: PWTs in the CCI group were signi?cantly lower than the sham group at Day1–30 after surgery, and reached its lowest at Day 1(P<0.01). After EA treatment, the PWTs recovered rapidly and were signi?cantly higher than those in the CCI group on 3, 7, 15 and 30 days after surgery(P<0.01). The numbers of NR2B-immunoreactive cells of the CCI group signi?cantly increased after CCI surgery compared with the sham group(P<0.01). Compared with the CCI group, stimulation of EA markedly decreased the numbers of NR2B-immunoreactive cells at Day 3, 7, 15 and 30(P<0.05). In the sham group, NR2B mRNA was expressed at a low level. It increased after CCI surgery, which increased rapidly at Day 7(P<0.01) and reached its peak value at Day 15(P<0.01). After EA stimulation, relative quantity of NR2B mRNA expression was less than that in the CCI group at Day 15 and 30(P<0.05). Conclusions: Low frequency of EA had antinociceptive effect in CCI rat model. The analgesic effects of EA might be through the inhibition of NR2B.