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.

Changes in N-methyl-D-aspartate receptor 2A subunit expression caused by binocular form deprivation and chondroitin sulfate proteoglycan degradation

Light deprivation is known to induce a significant decrease in the percentage of N-methyi-D- aspartate receptor 2A subunit （NR2A）-expressing neurons during development. The purpose of this study was to investigate the effects of binocular form deprivation （BFD） and chondroitin sulfate proteoglycan （CSPG） degradation on NR2A expression via an immunohistochemical study, around the end of a critical developmental period. The results show that the positive staining of NR2A in the normal rat visual cortex increases gradually from postnatal 3-5 weeks （P 〈 0.05）, but the changes from 5 weeks to 7 weeks were not significant. The positive staining of NR2A following BFD in the rat visual cortex slightly increased from postnatal 3-7 weeks （P 〉 0.05）. The positive staining of NR2A in the CSPG-treated group was insignificant compared with the BFD group at the same time point from 4 weeks to 7 weeks （P 〉 0.05）. Thus, the effect of BFD on NR2A expression in the rat visual cortex was similar to that of CSPG degradation around the end of the critical developmental period.

N-methyl-D-aspartate receptor subunit 1 regulates neurogenesis in the hippocampal dentate gyrus of schizophrenia-like mice

N-methyl-D-aspartate receptor hypofunction is the basis of pathophysiology in schizophrenia. Blocking the N-methyl-D-aspartate receptor impairs learning and memory abilities and induces pathological changes in the brain. Previous studies have paid little attention to the role of the N-methyl-D-aspartate receptor subunit 1 (NR1) in neurogenesis in the hippocampus of schizophrenia. A mouse model of schizophrenia was established by intraperitoneal injection of 0.6 mg/kg MK-801, once a day, for 14 days. In N-methyl-D-aspartate-treated mice, N-methyl-D-aspartate was administered by intracerebroventricular injection in schizophrenia mice on day 15. The number of NR1-, Ki67- or BrdU-immunoreactive cells in the dentate gyrus was measured by immunofluorescence staining. Our data showed the number of NR1-immunoreactive cells increased along with the decreasing numbers of BrdU- and Ki67-immunoreactive cells in the schizophrenia groups compared with the control group. N-methyl-D-aspartate could reverse the above changes. These results indicated that NR1 can regulate neurogenesis in the hippocampal dentate gyrus of schizophrenia mice, supporting NR1 as a promising therapeutic target in the treatment of schizophrenia. This study was approved by the Experimental Animal Ethics Committee of the Ningxia Medical University, China (approval No. 2014-014) on March 6, 2014.

Controlling N-methyl-D-aspartate receptor subunit 1 with calcitonin gene related peptide after cerebral ischemic injury

BACKGROUND: Activation of N-methyl-D-aspartate receptor (NMDAR) is a key link of exitotoxicity at the phase of cerebral ischemic injury. Because NMDAR is a main way to mediate internal flow of Ca2+ among glutamic acid receptors, over-excitation can cause neuronal apoptosis. Calcitonin gene related peptide has a strongly biological activity. On one hand, it can protect ischemic neurons through inhibiting the expression of NMDAR1 mRNA; on the other hand, it can play the protective effect through down-regulating the expression of NMDAR1 mRNA by exogenous calcitonin gene related peptide. OBJECTIVE: To observe the expression of NMDAR1 and the regulatory effect of calcitonin gene related peptide on the expression of NMDAR1 mRNA and protein in the cerebral cortex of rats with focal cerebral ischemia/reperfusion (I/R). DESIGN: Randomized controlled animal study. SETTING: China Medical University. MATERIALS: A total of 216 healthy male Wistar rats, general grade, weighing 250-280 g, were selected in this study. Twelve rats were randomly selected to regard as control group; meanwhile, other 204 rats were used to establish middle cerebral artery occlusion/reperfusion (MACO) models. The main reagents were detailed as follows: calcitonin gene related peptide (Sigma Company); calcitonin gene related peptide kit (Boster Company); antibody Ⅰ, Ⅱ and antibody β-actin Ⅰ, Ⅱ of NMDAR1 mRNA and chemiluminescence reagent (Santa Cruz Company, USA). METHODS: The experiment was carried out in the Laboratory of Neurobiology of China Medical University from August 2005 to June 2006. ① Right MCAO models of rats were established to cause focal ischemia and scored based on Zea Longa five-grade scale. If the scores were 1, 2 and 3 after wakefulness, the MACO models were established successfully and involved in the experiment. A total of 120 rats with successful modeling were randomly divided into I/R group and administration group with 60 in each group. All rats in the both groups were observed at five time points, including 6, 12, 24, 48 and 72 hours after reperfusion and after 2-hour ischemia, with 12 experimental animals at each time point. Six rats were prepared for detection of hybridization in situ, and the other 6 were used for Western blotting histochemical detection. Rats in the control group were opened their skin to separate common carotid artery and not treated with line and drugs. In addition, rats in the I/R group were treated with 1 mL saline at 2 hours after focal cerebral ischemia, and then, rats in the administration group were treated with 1 mL (1 g/L) calcitonin gene related peptide at 2 hours after focal cerebral ischemia. ② The expression of NMDAR1 mRNA was detected with hybridization in situ at various time points; moreover, the expression of NMDAR1 protein was measured with Western blotting method at various time points. The results were analyzed with Metamoph imaging analytical system. MAIN OUTCOME MEASURES: The expression of NMDAR1 mRNA and its protein in cortical neurons of rats at various time points. RESULTS: A total of 84 rats were excluded because of non-symptoms, exanimation or death; and then, 132 rats were involved in the final analysis. The expression of NMDAR1 mRNA and its protein in cortical neurons of rats in the control group was 0.205±0.001 and 0.184±0.001, respectively; after I/R, expression of NMDAR1 mRNA and its protein was up-regulated, especially, expression of mRNA at 6, 12, 24, 48 and 72 hours was 0.245±0.003, 0.287±0.004, 0.354±0.008, 0.284±0.002 and 0.217±0.006, respectively; moreover, expression of protein at 6, 12, 24, 48 and 72 hours was 0.222±0.003, 0.261±0.028, 0.311±0.004, 0.259±0.013 and 0.210±0.008, respectively. There was significant difference between the two groups (0.205±0.001, P < 0.01). The expression was up-related in the former 24 hours, reached peak at 24 hours, down-regulated, and decreased to the level of control group at 72 hours. Except 72 hours, the expression of NMDAR1 mRNA and its protein was lower in administration group than that in I/R group at other four time points. In addition, the expression of mRNA at 6, 12, 24, 48 and 72 hours was 0.223±0.005, 0.243±0.001, 0.292±0.002, 0.250±0.003 and 0.213±0.003, respectively; moreover, the expression of protein at 6, 12, 24, 48 and 72 hours was 0.216±0.006, 0.245±0.025, 0.276±0.003, 0.241±0.045 and 0.202±0.013, respectively. There was significant difference at various time points (P < 0.05). CONCLUSION: The expressions of NMDAR1 mRNA and its protein of peripheral cortical neurons are up-related in ischemic area after focal cerebral I/R. Meanwhile, exogenous calcitonin gene related peptide can protect cortical neurons through inhibiting expression of NMDAR1 mRNA and its protein after focal cerebral I/R.

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.

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.

Expression of gamma-aminobutyric acid type A receptor α_2 subunit in the dorsal root ganglion of rats with sciatic nerve injury

The γ-aminobutyric acid neurotransmitter in the spinal cord dorsal horn plays an important role in pain modulation through primary afferent-mediated presynaptic inhibition. The weakening of γ-aminobutyric acid-mediated presynaptic inhibition may be an important cause of neuropathic pain. γ-aminobutyric acid-mediated presynaptic inhibition is related to the current strength of γ-aminobutyric acid A receptor activation. In view of this, the whole-cell patch-clamp technique was used here to record the change in muscimol activated current of dorsal root ganglion neurons in a chronic constriction injury model. Results found that damage in rat dorsal root ganglion neurons following application of muscimol caused concentration-dependent activation of current, and compared with the sham group, its current strength and γ-aminobutyric acid A receptor protein expression decreased. Immunofluorescence revealed that γ-aminobutyric acid type A receptor α2 subunit protein expression decreased and was most obvious at 12 and 15 days after modeling. Our experimental findings confirmed that the y-aminobutyric acid type A receptor α2 subunit in the chronic constriction injury model rat dorsal root ganglion was downregulated, which may be one of the reasons for the reduction of injury in dorsal root ganglion neurons following muscimol-activated currents.

Effects of physical exercise on the developmental expression of hippocampal zinc transporter 1 and glutamate receptor subunit 2, and on cognitive function in a rat model of recurrent neonatal seizure

BACKGROUND： Developmental seizures are pathologically characterized by regenerative sprouting of hippocampal mossy fibers rich in Zn^2＋. Zn^2＋ metabolism in the mossy fiber pathway, and Zn^2＋ accumulation in presynaptic membrane vesicles, are dependent on zinc transporter 1 （ZnT1） and glutamate receptor subunit 2 （GluR2）. OBJECTIVE： To investigate the effects of long-term recurrent neonatal seizure, in the presence and absence of physical exercise, on the developmental expression of hippocampal zinc transporter 1 （ZnT1） and GluR2, and on cognitive function in rats. DESIGN, TIME AND SETTING： Based on behavioral examination and molecular biological research, a randomized, controlled animal experiment was performed at the Department of Neurobiology, Medical College of Soochow University, between January 2007 and April 2008. MATERIALS： Twenty-one 6-day-old Sprague Dawley rats of either gender were employed in this study. ZnT1 mRNA in situ hybridization kit was provided by Tianjin Haoyang Biological Manufacture Co.,Ltd., China. Rabbit anti-GluR2 was purchased from Santa Cruz Biotech, Inc, USA. METHODS： Rats were randomly divided into a recurrent seizure group （n = 11） and a control group （n = 10）. In the recurrent seizure group, 30-minute seizure was induced by flurothyl gas inhalation for a total of 6 consecutive days. Rats from the control group underwent experimental procedures similar to the recurrent seizure group, with the exception of flurothyl gas inhalation. Thirty minutes of treadmill exercise was performed daily by all rats at postnatal days 51–56. MAIN OUTCOME MEASURES： At postnatal day 82, rat hippocampal tissue was harvested for analysis of hippocampal ZnT1 and GluR2 expression by in situ hybridization and immunohistochemistry, respectively. Rat learning and memory capabilities were examined using the Y-maze test. RESULTS： In the recurrent seizure group, the gray scale value of ZnT1 in situ hybridization positive neurons in the hippocampal CA3 region was significantly greater （P 〈 0.05）, while the gray scale value of GluR2 immunoreactive neurons in the hippocampal hilus and dentate gyrus was significantly lower （P 〈 0.05）, than in the control group. At postnatal days 29–35, numbers of trials to criteria for successful learning were greater in the recurrent seizure group than in the control group （P 〈 0.05）; at postnatal days 61–67, the numbers of trials to criteria for successful learning were similar between the two groups （P 〉 0.05）. At postnatal days 29–35 and 61–67, there was no significant difference in memory capability between the recurrent seizure and control groups （P 〉 0.05）. CONCLUSION： Physical exercise likely improves the learning deficits caused by recurrent neonatal seizure in rats during brain development by modulating ZnT1 and GluR2 expression.

Gamma-aminobutyric acid A receptor gamma 2 subunit following Mg-free-induced seizures in cultured developing neurons

BACKGROUND： Studies have demonstrated that in vitro cultured cortical neurons from embryonic rats can produce spontaneous recurrent epileptiform discharges following transient Mg^2＋-free extracellular solution culture. OBJECTIVE： To explore gammaminobutyric acid A receptor （GABAAR）γ 2 subunit expression following Mg^2＋-free-induced seizures in cultured developing neurons. DESIGN, TIME AND SETTING： Cellular and molecular biology. The in vitro experiment was performed at the Department of Pediatrics, Second Xiangya Hospital of Central Southern University between January 2007 and February 2008. MATERIALS： Cortical neurons of Wistar rats on gestational days 16-17 were used. Normal extracellular solution （pH 7.3） consisted of NaCl 145 mmol/L, KCl 2.5 mmol/L, HEPES l0 mmol/L, MgC12 1 mmol/L, CaC12 2 mmol/L, glucose 10 mmol/L, and glycine 0.01 mmol/L. In addition, there was no MgCl2 in the Mg^2＋-free extracellular solution. METHODS： Cortical neurons cultured for 6 days were exposed to normal extracellular solution （control group） and Mg^2＋-free media （Mg^2＋-free group） respectively for 3 hours, followed by continuous culture in DMEM solution. MAIN OUTCOME MEASURES： On days 1, 7 and 12 after Mg^2＋-free treatment, real-time RT-PCR, immunochemistry, and flow cytometry were used to detect GABAAR 3/2 subunit expression. RESULTS： Compared with the control group, GABAAR γ-positive cells decreased significantly on days 1 and 7 after Mg^2＋-free treatment （P 〈 0.01）, but significantly increased on day 12 （P 〈 0.01 ）. GABAAR γ2 subunit mRNA expression decreased significantly at 7 days Mg^2＋-free treatment when measured by real-time RT-PCR compared with the control group （P 〈 0.05）. CONCLUSION： GABAAR γ2 subunit expression is modified following Mg-free-induced seizures in cultured developing neurons. This indicates the possibility that abnormal GABAA receptor expression might play an important role in development of neuronal injury.

Attenuation of nicotine-evoked Ca²⁺influx by antibody to the nicotinic acetylcholine receptor <i>α</i>3 subunits in human embryonic kidney cells

Autoantibody against neuronal nicotinic acetylcholine receptor (nAChR) α3 subunit is implicated in severe autonomic dysfunction in the patients with autoimmune autonomic ganglionopathy (AAG). Although this autoantibody has been revealed to impair fast excitatory synaptic transmission in autonomic ganglia, its precise mechanism remains unknown. Here, we show that antibody-induced reduction of cell-surface α3 subunits result in impairment of nicotine-evoked Ca2+ influx in stably transfected human embryonic kidney cells. These effects of the antibody were remarkably inhibited by interfering with the endocytic machinery at low-temperature. We conclude that reduction of nAChR in autonomic ganglia can be mediated by the endocytosis of α3 subunits, and resulted in autonomic failure in AAG patients.

Influences of Microwave on the Cognitive Function of Chickling and the Gene Expression of NMDA Receptor Subunit

[Objective] The research aimed to study the effects of microwave on the chick embryo development and the cognitive function of chickling. [Method] The microwave which was transmitted by the permatron and was 2 450 MHz was used to simulate the microwave radiation source to radiate the hatching eggs until the chickling was hatched out. The disposable passive avoidance learning and RT-PCR were respectively used to detect the influences of microwave on the cognitive function of chickling and the expression amounts of NMDA receptor NR1 and NR2 subunits. [Result] After the microwave radiation,the avoidance rate of exposed group was significantly lower than that in the control group. Especially the avoidance rate of highest radiation intensity group was extremely significantly lower than that in the control group. Meanwhile,the body weights of two groups of chickling in the exposed group increased,and the hatching time in one group increased. Via RT-PCR analysis,the expression amount of NR2 subunit increased on the 10th day and the 15th day. The expression amount of NR1 subunit only decreased on the 15th day. [Conclusion] The microwave had the certain influence on the individual development. By changing the structure composition and function of NMDA receptor in the endbrain,the microwave made the self-regulation ability of chickling decline,which had the certain damage on the cognitive function.

PIK3CA突变与乳腺癌临床病理特征及预后的相关性

目的探讨乳腺癌标本中磷脂酰肌醇激酶-3-催化亚基α(PIK3CA)突变与侵袭性乳腺癌临床病理特征及预后的相关性。方法收集2018年1月至2020年1月确诊为乳腺癌的181例患者临床病理资料,用免疫组织化学(IHC)法检测乳腺癌雌激素受体(ER)、孕激素受体(PR)、人表皮生长因子受体2(HER2)、Ki-67等指标,RT-qPCR检测乳腺癌中PIK3CA外显子9(exon9)和外显子20(exon20)的突变。结果181例侵袭性乳腺癌中PIK3CA突变70例,其中31例(44.28%)exon9突变、39例(55.71%)exon20突变。PIK3CA突变与乳腺癌分子分型有明显差异(P<0.05)。PIK3CA突变与乳腺癌的Ki67表达有明显差异(P<0.05)。34例(48.57%)HR+/HER2-组PIK3CA突变,36例(51.43%)非HR+/HER2-组突变,二者PIK3CA突变分布有明显差异(P<0.05)。PIK3CA突变患者病死率高于PIK3CA野生型(P<0.05)。结论PIK3CA突变与乳腺癌分子分型、Ki67增值指数及预后相关,可为患者精准治疗提供参考。

抗CD25单克隆抗体对肾移植受者CD4^+CD25^(high)调节性T细胞的影响

目的评价抗CD25单克隆抗体对肾移植受者术后早期CD4+CD25high调节性T细胞(CD4+CD25 high Treg)的影响。方法2007年2-9月接受初次亲属活体供肾移植的受者41例,根据是否使用抗CD25单克隆抗体(商品名daclizumab)分为抗体组(21例)和对照组(20例)。其中抗体组在肾移植术前2h及术后第14天分别给予抗CD25单抗各50mg。在移植前及移植后第13、17、60天分别留取肝素抗凝外周血15ml。应用流式细胞仪测定两组受者外周血CD4+T细胞和CD4+CD25 high Treg比例的变化,半定量RT-PCR检测CD25 mRNA的表达变化。结果肾移植术后13、17、60d抗体组的CD25+T细胞占CD4+T细胞的比例(20%±8%、13%±7%、24%±9%)低于对照组(45%±6%、41%±5%、40%±6%),差异有统计学意义(P<0.05)。抗体组术后第17天CD4+CD25 high Treg占CD4+T细胞的比例为4.40%±0.26%,明显低于对照组(8.56%±0.36%,P<0.01);而术后13、60d抗体组CD4+CD25 high Treg所占比例分别为7.00%±0.47%、3.75%±0.19%,与对照组(分别为8.04%±0.32%、3.66%±0.31%)比较差异无统计学意义(P>0.05)。抗体组CD25 mRNA相对表达水平在给予第二次抗体前(术后第13天)为1.65±0.22,术后第17天为1.84±0.27,两者间差异无统计学意义(P>0.05)。对照组术后第17天CD25 mRNA相对表达水平为1.70±0.23,与抗体组比较差异无统计学意义(P>0.05)。结论两剂共100mg抗CD25单抗仅一过性地降低CD4+CD25 high Treg,不会影响其活化扩增,无损于术后早期的免疫耐受诱导及维持。

全面性癫癎伴热性惊厥附加症家系γ-氨基丁酸A型受体γ2亚单位基因研究

目的研究全面性癫癎伴热性惊厥附加症(GEFS+)患者的γ-氨基丁酸A型受体γ2亚单位(GABRG2)基因分布。方法对10个家系先证者的GABRG2基因进行体外扩增及测序分析。结果发现一核苷酸多态位点,未发现已报道的突变。结论GABRG2基因突变在我国北方汉族人分布并不普遍。

携带抗白细胞介素-2受体α单抗靶向超声微泡和对比超声结合评价肾缺血-再灌注损伤

目的探讨携带抗白细胞介素-2受体α(IL-2Rα)单抗靶向超声微泡和对比超声结合评价肾缺血再灌注损伤(IRI)的可行性。材料与方法采用"亲和素-生物素"桥接法构建携抗IL-2Rα靶向超声微泡(MBIL-2Rα)和携同型抗体对照微泡(MB)。10只左肾缺血50min的小鼠,再灌注24h后,随机先后注入MBIL-2Rα和MB(间隔30min),分别于注入5min后行对比超声检查,并测量肾的声强度(VI)。结果对比超声图像显示MBIL-2Rα组左肾造影显著增强,VI值高达21.6±4.8U,而在MB组左肾仅见轻度造影增强,VI值为9.7±2.9U,两组间差异有统计学意义(P<0.05)。但无论是MBIL-2Rα组还是MB组左肾VI值均明显高于右侧肾脏VI值(3.8±1.5U,3.7±1.7U,P<0.05)。两组右侧肾脏之间VI值未见明显差异。结论 MBIL-2Rα和对比超声相结合能够有效评价肾IRI,从而对肾移植后的排斥反应提供有价值的信息。

Acute and chronic excitotoxicity in ischemic stroke and late-onset Alzheimer's disease

Stroke and Alzheimer's disease are common neurological disorders and often occur in the same individuals.The comorbidity of the two neurological disorders represents a grave health threat to older populations.This review presents a brief background of the development of novel concepts and their clinical potentials.The activity of glutamatergic N-methyl-D-aspartate receptors and N-methyl-D-aspartate receptor-mediated Ca^(2+)influx is critical for neuronal function.An ischemic insult induces prompt and excessive glutamate release and drastic increases of intracellular Ca^(2+)mainly via N-methyl-D-aspartate receptors,particularly of those at the extrasynaptic site.This Ca^(2+)-evoked neuronal cell death in the ischemic core is dominated by necrosis within a few hours and days known as acute excitotoxicity.Furthermore,mild but sustained Ca^(2+)increases under neurodegenerative conditions such as in the distant penumbra of the ischemic brain and early stages of Alzheimer's disease are not immediately toxic,but gradually set off deteriorating Ca^(2+)-dependent signals and neuronal cell loss mostly because of activation of programmed cell death pathways.Based on the Ca^(2+)hypothesis of Alzheimer's disease and recent advances,this Ca^(2+)-activated“silent”degenerative excitotoxicity evolves from years to decades and is recognized as a unique slow and chronic neuropathogenesis.The N-methyl-D-aspartate receptor subunit GluN3A,primarily at the extrasynaptic site,serves as a gatekeeper for the N-methyl-D-aspartate receptor activity and is neuroprotective against both acute and chronic excitotoxicity.Ischemic stroke and Alzheimer's disease,therefore,share an N-methyl-D-aspartate receptor-and Ca^(2+)-mediated mechanism,although with much different time courses.It is thus proposed that early interventions to control Ca^(2+)homeostasis at the preclinical stage are pivotal for individuals who are susceptible to sporadic late-onset Alzheimer's disease and Alzheimer's disease-related dementia.This early treatment simultaneously serves as a preconditioning therapy against ischemic stroke that often attacks the same individuals during abnormal aging.

丙泊酚通过组蛋白脱乙酰酶2/环磷酸腺苷反应元件结合蛋白/N-甲基-D-天冬氨酸-2B受体信号通路对子代大鼠学习和记忆功能的影响

目的探讨孕早期母体丙泊酚暴露对子代大鼠学习和记忆功能的影响。方法选取孕5-7 d的SD大鼠40只,采用随机数字表法将其分为A、B、C、D组,每组各10只。A组为对照组,B、C和D组妊娠大鼠分别注射0.25%、0.5%和0.75%的丙泊酚。子代大鼠出生后,根据是否给予组蛋白脱乙酰酶2(histone deacetylase 2,HDAC2)抑制剂将其分为CS组(A组子代大鼠给予HDAC2抑制剂)、I0.25S组(B组子代大鼠给予HDAC2抑制剂)、I0.5S组(C组子代大鼠给予HDAC2抑制剂)、I0.75S组(D组子代大鼠给予HDAC2抑制剂)、CN组(A组子代大鼠不给予HDAC2抑制剂)、I0.25N组(B组子代大鼠不给予HDAC2抑制剂)、I0.5N组(C组子代大鼠不给予HDAC2抑制剂)和I0.75N组(D组子代大鼠不给予HDAC2抑制剂),每组各10只。比较各组子代大鼠Morris水迷宫实验结果、海马HDAC2、环磷酸腺苷反应元件结合蛋白(cAMP response element binding protein,CREB)、N-甲基-D-天冬氨酸-2B受体(N-methyl-D-aspartate receptor 2B subunits,NR2B)mRNA及NR2B蛋白表达水平。结果第1-4天I0.25N组、I0.5N组、I0.75N组子代大鼠的逃避潜伏期均显著长于CN组(均P<0.05),I0.75S组大鼠平台穿越次数显著少于CS组(P<0.05),I0.25S组、I0.5S组、I0.75S组子代大鼠目标象限停留时间分别显著长于I0.25N组、I0.5N组、I0.75N组(均P<0.05)。当丙泊酚的暴露剂量增加,细胞出现线粒体空泡和高尔基体肿胀,HDAC2抑制剂可减轻丙泊酚暴露引起的子代海马功能障碍。I0.25N组、I0.5N组、I0.75N组子代大鼠海马HDAC2 mRNA表达水平均显著低于CN组(均P<0.05),CS组、I0.25S组、I0.5S组、I0.75S组子代大鼠海马HDAC2 mRNA水平分别显著低于CN组、I0.25N组、I0.5N组、I0.75N组(均P<0.05);CS组、I0.25S组、I0.5S组、I0.75S组子代大鼠海马CREB mRNA水平分别显著高于CN组、I0.25N组、I0.5N组、I0.75N组(均P<0.05);I0.25S组、I0.5S组和I0.75S组子代大鼠海马NR2B mRNA和NR2B蛋白表达水平分别显著高于I0.25N组、I0.5N组和I0.75N组(均P<0.05)。结论孕早期母体丙泊酚暴露损害子代大鼠学习和记忆功能,机制与其调节子代大鼠海马HDAC2/CREB/NR2B蛋白表达有关。

当归补血汤对2型糖尿病大鼠IRS-1/PI3K/Akt2信号通路的影响研究

目的探讨当归补血汤对2型糖尿病大鼠胰岛素受体底物1(IRS-1)、磷脂酰肌醇3激酶p85亚基(PI3Kp85)、蛋白激酶B(Akt2)表达的影响。方法取8只雄性ZDF(fa/+)大鼠作为对照组;另取24只雄性ZDF(fa/fa)大鼠给予3周高脂饲料建立2型糖尿病模型,然后将造模成功大鼠随机分为模型组、盐酸二甲双胍组、当归补血汤组,每组8只。盐酸二甲双胍组给予盐酸二甲双胍肠溶片300 mg/kg灌胃,当归补血汤组给予当归补血汤(配方颗粒加蒸馏水配制)12.8 g/kg灌胃,对照组和模型组给予等量生理盐水灌胃,均1次/d,连续8周。末次灌胃后,禁食14 h进行口服葡萄糖耐量试验,计算胰岛素生成指数、胰岛素抵抗指数(HOMA-IR)和胰岛β细胞功能指数(HOMA-β);糖耐量试验结束后隔天禁食12 h抽取腹主动脉血,检测丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)水平;取各组大鼠肝脏组织,采用RT-qPCR法检测IRS-1、PI3Kp85和Akt2 mRNA表达情况,采用Western blot法检测IRS-1、p-IRS1、PI3Kp85、p-PI3Kp85、Akt2、p-Akt2蛋白表达情况。结果模型组大鼠空腹血糖水平、空腹胰岛素水平、血糖曲线下面积、HOMA-IR均明显高于对照组(P均<0.05),胰岛素生成指数、HOMA-β均明显低于对照组(P均<0.05);盐酸二甲双胍组和当归补血汤组空腹血糖水平、空腹胰岛素水平、血糖曲线下面积、HOMA-IR均明显低于模型组(P均<0.05),胰岛素生成指数、HOMA-β均明显高于模型组(P均<0.05),当归补血汤组各指标改善情况均明显优于二甲双胍组(P均<0.05)。与对照组比较,模型组大鼠血清ALT、AST、TC、TG、LDL-C水平均明显升高(P均<0.05),HDL-C水平明显降低(P<0.05);与模型组比较,盐酸二甲双胍组和当归补血汤组大鼠血清ALT、AST、TC、TG、LDL-C水平均明显降低(P均<0.05),HDL-C水平均明显降低(P均<0.05);除ALT、TC外,其余指标当归补血汤组改善情况均明显优于盐酸二甲双胍组(P均<0.05)。模型组大鼠肝脏组织中IRS-1、PI3Kp85、Akt2 mRNA表达量和IRS-1、p-IRS1、PI3Kp85、p-PI3Kp85、Akt2、p-Akt2蛋白表达量均明显低于对照组(P均<0.05),盐酸二甲双胍组和当归补血汤组上述各指标表达量均明显高于模型组(P均<0.05);除Akt2 mRNA、p-Akt2外,其余指标当归补血汤组均明显高于盐酸二甲双胍组(P均<0.05)。结论当归补血汤可能通过调节IRS-1/PI3K/Akt2信号通路发挥治疗2型糖尿病的作用。

Bcl-2、Bax蛋白在NRs抗体预处理后缺氧缺糖海马脑片CA_1区的表达变化

运用海马脑片培养技术、海马脑片缺氧缺糖方法、免疫组织化学染色和图像分析处理技术观察用 NMDA受体亚单位抗体预处理后再缺氧缺糖的海马脑片 CA1 区 Bcl-2和 Bax蛋白的表达变化 ,以探究其亚单位与海马脑片缺氧缺糖性损伤的关系。结果显示 ,各实验组海马脑片 CA1 区均有不同程度 Bcl-2、Bax蛋白表达和细胞缺失形成的空洞。 Bcl-2蛋白在 NR1+ OGD组、NR2 A+ OGD组和 NR2 A + NR2 B+ OGD组 CA1 区的表达均明显弱于 OGD组 (3组均 P<0 .0 5 ) ;其在 NR2 B+ OGD组和HOTC组的表达则强于 OGD组 (两者 P<0 .0 5 )。 Bax蛋白在 NR1+ OGD组、NR2 A+ OGD组和 NR2 A+ NR2 B+ OGD组的表达均强于 OGD组 (NR2 A+ OGD组 P<0 .0 5 ) ;在 NR2 B+ OGD组和 HOTC组其表达则明显弱于 OGD组 (后者 P<0 .0 5 )。结论 :单纯缺氧缺糖可引起海马脑片 CA1 区锥体细胞的迟发性损伤 ,同时引起 Bcl-2蛋白和 Bax蛋白的表达变化 ;预加 NMDA受体亚单位 NR1、NR2 A抗体和 NR2 A+ NR2 B抗体可以加重缺氧缺糖性海马脑片 CA1 区细胞损伤程度 ;预加 NR2 B抗体则可减轻其损伤程度。提示 NMDA受体亚单位成分的变化可以调节 Bcl-2和 Bax蛋白在缺氧缺糖性海马脑片 CA1 区的表达 ,从而调节CA1

Giβγ亚基介导的磷脂酶A_2激活在激动剂所致CCL137细胞毒蕈碱性乙酰胆碱受体失敏中的作用

卡巴胆碱（ＣＣｈ）所致ＣＣＬ１３７细胞中磷脂酶Ａ２（ＰＬＡ２）激活和毒蕈碱性乙酰胆碱受体（ｍＡＣｈＲ）结合能力降低，均呈浓度和时间依赖关系，且ＰＬＡ２激活早于ｍＡＣｈＲ对配基结合量的降低，所需浓度亦小于后者．可使Ｇｉ蛋白失活的百日咳杆菌毒素能阻抑ＣＣｈ所引起的变化，表明Ｇｉ蛋白在其中起着某种作用．应用各种抗Ｇｉα，抗Ｇｉβγ或抗β血清，测知ＣＣｈ可使Ｇｉα明显减少，而游离的βγ和β亚基的量不变．足够量的抗Ｇ蛋白β亚基血清可完全阻抑ＣＣｈ所致ＰＬＡ２活性和ｍＡＣｈＲ结合能力的变化．结果提示，Ｇｉ蛋白βγ亚基激活的ＰＬＡ２在ＣＣｈ所致ＣＣＬ１３７细胞ｍＡＣｈＲ失敏中起关键作用．