白介素-6保护小脑颗粒神经元抗谷氨酸的神经毒性作用

目的：探讨白介素-6（IL-6）对谷氨酸诱导的神经元损伤的防治作用及其作用机制。方法：用IL-6慢性预处理培养的小脑颗粒神经元,然后后用谷氨酸急性刺激小脑颗粒神经元。用噻唑兰（MTT）比色法和末端脱氧核苷酸转移酶介导的原位缺口末端标记（TUNEL）法分别观察神经元的功能和凋亡的变化;用激光扫描共聚焦显微镜（LSCM）和逆转录聚合酶链式反应（RT—PCR）法分别检测神经元内Ca^2＋浓度的动态变化和IL-6信号转导蛋白gp130 mRNA的表达。结果：IL-6（2．5、5和10ng／ml）慢性预处理培养的小脑颗粒神经元,可浓度依赖性地改善谷氨酸诱导的神经元活性降低;并可明显减少谷氨酸诱导的神经元凋亡;还可显著抑制谷氨酸激发的神经元内Ca^2＋超载。此外。经IL-6慢性预处理的小脑颗粒神经元表达gp130mRNA明显低于未经IL-6预处理的神经元。结论：IL-6能保护神经元抵抗由谷氨酸诱导的兴奋毒性作用,IL-6的这种神经保护机制可能与它抑制神经元内Ca^2＋超载密切相关,而且可能由gp130细胞内信号转导途径介导。     

非NMDA受体参与双相呼气和吸气神经元电活动的调节

在新生大鼠延髓脑片上同步记录舌下神经根和双相呼气神经元／吸气神经元单位的放电活动,并在灌流的改良Kredbs液中先后加以非NMDA受体的激动剂KA和拮抗剂DNQX,观察对神经元单位放电的影响,以进一步探讨非NMDA受体在对双相呼气神经元之间交互兴奋和吸气神经元兴奋性突触输入中的作用,结果表明,使用非NMDA受体激动剂KA以后,双相呼气神经元的放电频率和蜂频率都明显增大,吸气神经元中期放电的频率和非NMDA受体激动剂KA以后,双相呼气神经元的放电频率和峰频率都明显增大,吸气神经元中期放电的频率和峰频率也显著增大,而早期和晚期放电的频率无明显改变,用相应拮抗剂以后,上述效应明显被抑制,结果提示,非NMDA受体参与了双相呼气神经元之间的交互兴奋作用,并且也介导了吸气神经元的兴奋性突触输入／     

小脑间位核和顶核对下丘脑外侧区神经元电活动的影响

电刺激猫小脑问位核和顶核可以影响下丘脑外侧区神经元的电活动,其中有一些神经元是葡萄糖敏感神经元.这一结果揭示小脑不仅具有经典的躯体运动调节功能,同时也可以通过小脑-下丘脑通路参与机体非躯体活动的调节.     

刺激面神经核对前包钦格复合体呼吸神经元放电活动的影响及其递质机制

实验选用健康成年SD大鼠,观察电刺激面神经核对前包钦格复合体(pre-—Boetzinger complex,PBC)呼吸神经元(RNs)放电活动的影响,并观察微电泳6-氰基-7-硝基喹喔啉-2,3-二酮(CNQX)、荷包牡丹碱(BIC)、士的宁(Stry)和阿托品(Atr)对电刺激面神经核引起的PBCRNs放电变化的拮抗效应,以进一步探讨面神经核是否参与呼吸调节及其可能的神经机制。在12只面运动神经元逆行溃变大鼠同侧PBC内共记录到各类RNs116个,电刺激溃变侧面神经核时,前吸气(Pre-I)神经元(24／26个)和吸气(I)神经元(30／35个)主要表现为兴奋,呼气(E)神经元(20／22个)和吸气-呼气(I-E)跨时相神经元(28／33个)表现为抑制。CNQx可完全或部分拮抗电刺激面神经核对Pre-I(18／24)和I(23／27)神经元的兴奋效应;Stry可拮抗电刺激面神经核对Pre-I(12／18)和I(14／23)神经元的瞬时抑制效应以及对I-E(20／28)和E(9／16)神经元的抑制效应;BIC可拮抗电刺激面神经核对I—E(22／25)和E(9／9)神经元的抑制效应;微电泳Atr对各类RNs的放电变化无明显作用。这些结果表明,面神经核非运动神经元可能通过向PBC的纤维投射,以Glu、GABA和Gly为神经递质或调质,调节PBC RNs的活动,从而参与对呼吸运动的调节。     

γ-氨基丁酸对离体大鼠延髓头端腹外侧区神经元单位放电的抑制作用

在７３张脑片上观察了γ－氨基丁酸（ＧＡＢＡ）对１０６个延髓头端腹外侧区（ＲＶＬＭ）神经元单位放电的影响。外源性的ＧＡＢＡ（０．１￣３．０ｍｍｏｌ／Ｌ）抑制了１０６神经元中的８４个神经元的电活动,这些抑制效应呈剂量－反应关系。ＧＡＢＡ的抑制效应大部分可被ＧＡＢＡＡ受体选择性拮抗剂荷苞牡丹碱甲基碘化物（ＢＭＩ）和Ｃｌ＾－通道阻断剂印防己毒素（ＰＴＸ）所阻断,而单独灌流ＢＭＩ和ＰＴＸ对ＲＶＬＭ神经元主要     

血清白介素-6和白介素-10浓度的变化与冠心病

目的探讨白介素-6(IL-6)、白介素-10(IL-10)在冠心病心绞痛患者血中的变化规律。方法检测25例不稳定型心绞痛、23例稳定型心绞痛患者及22例正常对照者组血中IL6、IL-10浓度并进行比较。结果不稳定型心绞痛组、稳定型心绞痛组及正常对照组血中IL-6分别为(298.6±52.4)、(143.2±46.9)、(75.1±32.7)pg/m l;不稳定型心绞痛组分别高于稳定型心绞痛组及正常对照组,差异均有非常显著性(均为P<0.001)。不稳定型心绞痛组、稳定型心绞痛组及正常对照组血IL-10分别为(173.7±30.9)、(80.4±15.6)、(38.2±7.5)pg/m l,不稳定型心绞痛组分别高于稳定型心绞痛组及正常对照组(P<0.01)。结论冠心病患者血清IL-6、IL-10的浓度升高。     

NMDA受体介导脑缺血/再灌注诱导GluR6 巯基亚硝基化的研究

目的:研究脑缺血再灌注以及联合给予脑缺血和NMDA(N-甲基-D-天冬氨酸)受体抑制剂MK801对大鼠海马CA1区Glu R6巯基亚硝基化以及海马CA1区锥体细胞凋亡的影响。方法:采用四动脉结扎法构建大鼠全脑缺血再灌注模型,给予SD大鼠腹腔注射NMDA受体特异性抑制剂MK801(3 mg/kg)。主要运用'生物素转化法'(Biotin-Switch method)、SDS-PAGE、免疫印迹、焦油紫染色等方法对Glu R6的巯基亚硝基化(S-亚硝基化)、蛋白表达水平以及海马CA1区锥体细胞的凋亡水平进行研究。结果:脑缺血/再灌注显著促进Glu R6的巯基亚硝基化以及海马CA1区锥体细胞的凋亡,给予NMDA受体特异性抑制剂MK801能够显著抑制脑缺血/复灌诱导增加的Glu R6的S-亚硝基化以及海马CA1区锥体细胞的凋亡。结论:脑缺血/再灌注早期NMDA受体介导了Glu R6的巯基亚硝基化以及海马CA1区锥体细胞的凋亡,从而为临床治疗缺血再灌注脑损伤提供了理论依据。     

去甲肾上腺素和乙酰胆碱对大鼠离体室旁核神经元放电活动的影响

用31个脑片观察了去甲肾上腺素(NA)和乙酰胆碱(ACh)对90个室旁核神经元放电活动的影响。脑片灌流 NA(10~(-6)mol/L,3min)后,14/78(17%)个非周期型放电单位和7/12(58.3%)个周期型放电单位的放电频率增加,10/78(12%)个非周期型放电单位和2/12(16.6%)个周期型放电单位的放电频率明显降低甚至完全停止,54/78(69%)非周期型单位和3/12(25%)个周期型单位无明显反应。NA 对非周期型放电单位的兴奋作用可被 α 受体阻断剂酚妥拉明完全阻断,而 NA 对周期型单位的兴奋作用只能被部分阻断。脑片灌流 ACh(10~(-7)mol/L,3min)后,使15/78(19%)个非周期型和6/12(50%)个周期型单位放电频率增加,9/78(11%)非周期型和2/12(16.6%)个周期型放电单位放电频率降低,54/78(69%)非周期型和4/12(33.3%)周期型单位无反应。阿托品或东莨菪碱可翻转 ACh 对它们的作用。实验提示,NA 和 ACh 对室旁核神经元的兴奋或抑制作用是分别由 α、β 和 Μ 受体介导的。     

皮质酮对原代培养海马神经元的毒性作用及NMDA受体亚基表达的改变

目的研究皮质酮对大鼠海马神经元的毒性作用及NMDA受体亚基表达的影响.方法以体外原代培养的大鼠海马神经元为研究对象,根据影响因素,即给予的不同浓度皮质酮和其它因素分为8个组:对照组、10-7mol/L皮质酮组(简称10-7组)、10-6mol/L皮质酮组(简称10-6组)、10-5mol/L皮质酮组(简称10-5组)、10-6 高糖组、10-5 高糖组、10-6mol/L MK801组和10-5mol/L MK801组,镜下观察不同浓度皮质酮作用下海马神经元形态学的变化,并采用MTT方法测量各组细胞存活率,利用免疫细胞化学结合图象分析对原代培养海马神经元NMDA受体亚基的表达进行观察.结果 10-6、10-5浓度的皮质酮对海马神经元影响较大,细胞存活率较对照组明显降低,但10-6 高糖组、 10-5mol/L 高糖组、10-6mol/L MK801及10-5mol/L MK801 4个组,分别与相同皮质酮浓度处理组比较,细胞存活率显著提高.10-6和10-5组海马神经元上NMDA受体亚基表达较对照组明显降低.10-7mol/L浓度的皮质酮对上述指标影响不大.结论过量的皮质酮对大鼠海马神经元具有损伤作用,NMDA受体参与了此过程,NMDA受体拮抗剂和高浓度葡萄糖可保护海马神经元.     

The role of receptor/channel activity in neuronal cell migration

Confocal laser microscopy, in conjunction with carbocyanine dyes and calcium-sensitive fluorescent indicators, was used in slices and explant cultures of developing cerebellum to study cellular mechanisms underlying a motility of neuronal cell migration. The results indicate that a combination of voltage- and ligand-activated ion channels cooperatively regulates Ca²⁺ influx into the migrating cells. We suggest that molecules, present in the local cellular milieu, affect cell motility by activating specific ion channels and second messengers that influence polymerization of stiff and contractile cytoskeletal proteins. This early interaction between postmitotic neurons and surrounding cells controls the rate of their movements, sculpts their shapes, establishes their positions, and, therefore, indirectly determines their identities to prior formation of synaptic connections. © 1995 John Wiley Sons, Inc.     

Prediction on the binding domain between human interleukin-6 and its receptor

Based on the spatial conformations of human interleukin-6 (hIL-6) derived from nuclear magnetic resonance analysis and human interleukin-6 receptor (hIL-6R) modeled with homology modeling method using human growth hormone receptor as template, the interaction between hIL-6 and its receptor (hIL-6R) is studied with docking program according to the surface electrostatic potential analysis and spatial conformation complement. The stable region structure composed of hIL-6 and hIL-6R is obtained on the basis of molecular mechanism optimization and molecular dynamics simulation. The binding domain between hIL-6 and hIL-6R is predicted theoretically. Furthermore, the especial binding sites that influence the interaction between hIL-6 and hIL-6R are confirmed. The results lay a theoretical foundation for confirming the active regions of hIL-6 and designing novel antagonist with computer-guided techniques.     

Prediction on the binding domain between human interleukin-6 and its receptor

Based on the spatial conformations of human interleukin-6 (hlL-6) derived from nuclear magnetic resonance analysis and human interleukin-6 receptor (hlL-6R) modeled with homology modeling method using human growth hormone receptor as template, the interaction between hlL-6 and its receptor (hIL-6R) is studied with docking program according to the surface electrostatic potential analysis and spatial conformation complement. The stable region structure composed of hlL-6 and hlL-6R is obtained on the basis of molecular mechanism optimization and molecular dynamics simulation. The binding domain between hIL-6 and hIL-6R is predicted theoretically. Furthermore, the especial binding sites that influence the interaction between hlL-6 and hlL-6R are confirmed. The results lay a theoretical foundation for confirming the active regions of hlL-6 and designing novel antagonist with computer-guided techniques.     

Role of the C-terminus in the activity, conformation, and stability of interleukin-6.

Two murine interleukin-6 (mIL-6) variants were constructed using the polymerase chain reaction (PCR), one lacking the last five residues (183-187) at the C-terminus (pMC5) and another with the last five residues of mIL-6 substituted by the corresponding residues of human IL-6 (pMC5H). The growth stimulatory activity of pMC5 on the mouse hybridoma cell line 7TD1 was < 0.05% of mIL-6, whereas pMC5H and mIL-6 were equipotent. The loss of biological activity of pMC5 correlated with its negligible receptor binding affinity on 7TD1 cells, while the binding of pMC5H was comparable to that of mIL-6. Both pMC5 and pMC5H, like mIL-6, failed to interact with recombinant soluble human IL-6 receptor when assayed by surface plasmon resonance-based biosensor analysis. These studies suggest that the C-terminal seven amino acids of human IL-6, alone, do not define species specificity for receptor binding. A variety of biophysical techniques, as well as the binding of a conformational-specific monoclonal antibody, indicated that the global fold of the mIL-6 variants was similar to that of mIL-6, although small changes in the NMR spectra, particularly for pMC5, were observed. Some of these changes involved residues widely separated in the primary structure. For instance, interactions involving Tyr-22 were influenced by the C-terminal amino acids suggesting that the N- and C-termini of mIL-6 are in close proximity. Equilibrium unfolding experiments indicated that pMC5 was 0.8 kcal/mol less stable than mIL-6, whereas pMC5H was 1.4 kcal/mol more stable. These studies emphasize the structural importance of the C-terminal amino acids of IL-6 and suggest that truncation or mutation of this region could lead to small but significant alterations in other regions of the molecule.     

Polymorphisms of interleukin-1 and interleukin-6 genes on the risk of ischemic stroke in a meta-analysis

Many epidemiological studies have investigated the associations between polymorphisms of interleukin-1 (IL1) and interleukin-6 (IL6) genes and risk of ischemic stroke (IS), but no conclusions are available because of conflicting results. The aim of this study was to assess the relationships by meta-analysis. The databases of Pubmed, Embase and Wangfang, updated to August 1st, 2011, were retrieved. Odds ratio (OR) and corresponding 95% confidence interval (95% CI) as effect size were calculated by a fixed- or random-effect model. In total, three case-control studies for IL1α-889C/T, eight studies for IL1β-511C/T, eight studies for IL1-Ra and seven studies for IL6-147G/C were included in this meta-analysis. Combined analysis indicated that IL1β-511C/T polymorphism was not overall associated with risk of IS [OR (95% CI)=1.22 (0.85-1.87) for TT vs. CC]. However, when subgroup analyses for countries were conducted, the results indicated that T allele was associated with increased risk of IS for Polish and associated with a trend of increased risk of IS for Chinese although it did not reach statistical significance [TT vs. CC: OR (95% CI)=1.97 (1.22-3.17) for Polish and 1.40 (0.99-1.99) for Chinese]. In addition, overall and subgroup analyses indicated that IL1α-889C/T, IL1-Ra and IL6-147G/C polymorphisms were also not associated with risk of IS [OR (95% CI)=1.21 (0.86-1.70) for TT vs. CC of IL1α-889C/T, 1.22 (0.85-1.75) for RN2/RN2 vs. RN1/RN1 for IL1-Ra and 1.09 (0.84-1.40) for G carriers vs. C carriers for IL6-147G/C]. This study inferred that IL1β-511C/T polymorphism might be moderately associated with increased risk of IS, but no sufficient evidence was available to support any associations between IL1-Ra and IL6-147G/C polymorphisms and IS. We could not draw a conclusion between IL1α-889C/T polymorphism and risk of IS based on the limited data, and further large sample-sized studies were required.     

Chronic ethanol exposure delays the 'developmental switch' of the NMDA receptor 2A and 2B subunits in cultured cerebellar granule neurons

Chronic ethanol treatment of cultured neurons from various brain areas has been found to increase NMDA receptor function and to alter the levels of some NMDA receptor subunit proteins. Because the cultured neurons are exposed to ethanol during a period when the NMDA receptor is undergoing developmental changes in subunit expression, we wished to determine whether ethanol treatment alters this developmental pattern. We found that 3 days of treatment of cerebellar granule neurons with ethanol, which was previously reported to increase NMDA receptor function, resulted in a delay in the 'developmental switch' of the NR2A and NR2B subunits, i.e. the developmental decrease in NR2B and increase in NR2A protein expression. As a result, the level of NR2B was higher, and that of NR2A was lower, in the ethanol-treated cells than in control cells. Cross-linking experiments showed that the changes in total receptor subunit proteins levels were reflected in cell-surface expressed proteins, indicating changes in the amount of functional receptors. These results were confirmed by a higher potency of glycine at the NMDA receptor in the ethanol-treated cells, as determined by NMDA/glycine-induced increases in intracellular Ca(2+). The results suggest that the mechanism by which ethanol alters NMDA receptor expression in cultured neurons, where receptors are undergoing development, differs from the mechanism of ethanol's effect on NMDA receptors in adult brain. Changes in the proportion of NR2A and NR2B subunits may contribute to effects of ethanol on neuronal development.     

Inhibitory effect of locally produced and exogenous interleukin-6 on tumor growth in vivo

In order to define the potential antitumor activity of the multifunctional cytokine interleukin-6 (IL-6), retrovirus-mediated gene transfer was used to introduce and express a cDNA encoding human IL-6 in the murine fibrosarcoma cell line Fsa-R. Although these genetically modified tumor cells appeared morphologically and phenotypically identical to control Fsa-R cells and had a similar plating efficiency in vitro, they were found to exhibit greatly reduced tumorigenicity in vivo following intravenous injection into syngeneic recipients. Exogenous IL-6 was shown to produce a similar inhibition of tumor growth in the lung if administered intraperitoneally. In contrast, tumor growth in subcutaneous sites was inhibited only if the tumor cells were engineered to express IL-6 locally, or if IL-6 was administered intratumorally. Intraperitoneal injection of IL-6 had no inhibitory effect. Tumors that did grow from IL-6-producing tumor cell inocula in subcutaneous sites were found to contain large numbers of macrophages. These results demonstrate that the antitumor activity of systemically administered IL-6 varies depending on the site of tumor growth and suggest an important role for IL-6 in the recruitment, proliferation and/or survival of tumor-associated macrophages.Supported by grants from the B. C. Health Care Research Foundation (BCHRF), the National Cancer Institute (NCI) and the National Cancer Institute of Canada (NCIC). G.J.D. is a Research Scientist of the National Cancer Institute of Canada (NCIC). R.S.L. is a RSNA Research and Education Fund Scholar     

血小板减小症模型制作及药效试验应用研究

[目的] 研究血小扳减少症模型复制的方法和皮下注射白细胞介索-6对小鼠血小板减少症治疗的效果。[方法] 采用12只BACB/C小鼠,雌雄各半,随机分为3组,皮下注射环磷酰胺;再将3个模型组随机设为阴性对照组、阳性对照组以及白细胞介索-6实验组,分别皮下注射稀释液、白细胞介素-11及白细胞介素-6,定时采血,分析血小板数目。[结果] ①与给药前相比,小鼠血小板减少极显著(P＜0．01);②阴性对照组与阳性对照组以及白细胞介素-6实验组之间差异极显著(P＜0．01）;③阳性对照组、白细胞介素-6实验组给药前相比差异极显著(P＜0．01)。[结论] 用环磷酰胺对BACB/C小鼠注射方法制造模型简单易行;白细胞介素-6在BACB/C小鼠以皮下注射给药途径方法,对治疗小鼠血小板减少症效果显著。