P2Y_(13)受体激活促进脊髓背角小胶质细胞钙浓度升高

目的:观察ADP对培养的脊髓背角小胶质细胞内Ca2+浓度([Ca2+]i)的影响及作用机制。方法:培养纯化新生SD大鼠脊髓背角小胶质细胞,免疫组化观察P2Y13受体表达,激光共聚焦显微镜检测ADP作用下,小胶质细胞[Ca2+]i的变化。结果:大鼠脊髓背角小胶质细胞表达P2Y13受体,ADP可导致培养的脊髓背角小胶质细胞[Ca2+]i快速增高,且呈现剂量依赖性;P2Y13受体拮抗剂MRS2211(100μmol/L)能基本阻断ADP的作用,而P2Y1受体拮抗剂MRS2179(100μmol/L)、P2Y12受体拮抗剂MRS2395(100μmol/L)均不影响ADP致小胶质细胞[Ca2+]i升高的效应。结论:ADP可能通过P2Y13受体途径,导致培养的脊髓背角小胶质细胞[Ca2+]快速升高。     

嘌呤P2Y受体激动剂ADPβS对脊髓来源小胶质细胞产生IL-1β、IL-6和TNF-α的刺激作用

目的:观察嘌呤P2Y受体激动剂ADPβS对脊髓背角来源小胶质细胞炎症因子IL-1β、IL-6和TNF-α表达和释放的影响。方法:培养新生SD大鼠脊髓背角小胶质细胞,PCR检测ADPβS作用下小胶质细胞IL-1β、IL-6和TNF-α在mRNA水平表达变化;ELISA检测ADPβS作用下小胶质细胞IL-1β、IL-6和TNF-α释放变化。结果:与正常对照组相比,ADPβS(10μmol/L)可以刺激脊髓背角小胶质细胞Iba-1、IL-1β、IL-6和TNF-αmRNA表达上调。P2Y_(12)受体拮抗剂MRS2395和P2Y_(13)受体拮抗剂MRS2211部分阻断ADPβS刺激小胶质细胞IL-1β、IL-6和TNF-αmRNA表达上调,MRS2395和MRS2211联合预处理几乎全部阻断ADPβS刺激小胶质细胞Iba-1、IL-1β、IL-6和TNF-αmRNA表达上调。结论:P2Y_(12)/P2Y_(13)受体激活可以促进脊髓背角小胶质细胞激活和IL-1β、IL-6和TNF-αmRNA表达上调及释放。     

AM1241抑制ADPβS诱发培养大鼠脊髓背角小胶质细胞P2Y_(12)和P2Y_(13)受体表达及炎症因子释放

目的:离体条件下,观察大麻素CB2受体激动剂AM1241对嘌呤P2Y受体激动剂ADPβS诱发的脊髓背角小胶质细胞P2Y_(12)和P2Y_(13)受体mRNA表达以及炎症因子IL-1β、IL-6和TNF-α释放的影响。方法:培养纯化新生SD大鼠(3 d)脊髓背角小胶质细胞,荧光定量PCR技术检测AM1241(10~(-5)mol/L,1 h)对ADPβS(10~(-5)mol/L,3 h)诱发的背角小胶质细胞P2Y_(12)和P2Y_(13)受体mRNA表达的影响;ELISA技术检测AM1241(10~(-5)mol/L,1 h)对ADPβS(10~(-5)mol/L,3 h)诱发的小胶质细胞IL-1β、IL-6和TNF-α释放的影响。结果:与正常对照组相比,ADPβS(10~(-5)mol/L,3 h)可以刺激脊髓背角小胶质细胞P2Y_(12)和P2Y_(13)受体在mRNA水平表达上调(P0.05),IL-1β、IL-6和TNF-α释放相应增加(P0.05)。AM1241(10~(-5)mol/L,1 h)几乎完全阻断ADPβS刺激小胶质细胞P2Y_(12)和P2Y_(13)受体mRNA表达上调以及IL-1β、IL-6和TNF-α释放的效应(P0.05);AM1241的这种抑制效应可以被CB2受体拮抗剂AM630(10~(-5)mol/L,1 h)反转(P0.05)。结论:大麻素CB2受体激活可以抑制ADPβS诱发的脊髓背角小胶质细胞P2Y_(12)和P2Y_(13)受体mRNA水平表达上调以及IL-1β、IL-6和TNF-α释放。     

皮质酮对大鼠脊髓背角星形胶质细胞活动的影响

目的:探讨皮质酮(corticosterone,CORT)对培养的大鼠脊髓背角星形胶质细胞活性的调节作用。方法:培养纯化新生SD大鼠脊髓背角星形胶质细胞,荧光双重标记技术检测培养的星形胶质细胞糖皮质激素受体(glucocorticoid receptor,GR)及胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)共表达;免疫印迹技术检测星形胶质细胞GFAP表达的变化;高效液相色谱法(high performance liquid chromatography,HPLC)检测星形胶质细培养液中谷氨酸含量。结果:培养的脊髓背角星形胶质细胞均表达GR;CORT孵育3 h可降低脊髓背角星形胶质细胞GFAP表达,GR拮抗剂RU38486可阻断CORT的作用;但CORT对星形胶质细胞谷氨酸释放无显著影响。结论:CORT可降低脊髓背角星形胶质细胞GFAP表达,但对谷氨酸释放无显著影响。     

P2Y1受体介导Aβ25-35所致大鼠星形胶质细胞活化

目的: 观察嘌呤受体P2Y₁在Aβ_25-35所致的大鼠星形胶质细胞活化中所起的作用。方法: 体外分离培养大鼠星形胶质细胞,按空白对照、Aβ_25-35和P2Y₁受体阻断剂MRS2179+Aβ_25-35和MRS2179分组干预后,通过免疫细胞化学、免疫荧光法和Western blotting方法观察GFAP和P2Y₁表达的变化。结果: 各组细胞数量无明显变化。与对照组相比,Aβ_25-35组GFAP荧光强度明显增加;MRS2179+Aβ_25-35和MRS2179组均降低,两组间无明显差异。Western blotting显示GFAP在各组间表达与免疫荧光法有相似趋势;与对照组相比,P2Y₁表达在Aβ_25-35组明显增多(P＜0.05)和MRS2179+Aβ_25-35和MRS2179组无明显变化(P＞0.05)。结论: Aβ_25-35通过P2Y₁受体活化激活星形胶质细胞。     

LPS对大鼠脊髓背角星形胶质细胞CXCL1和CCL2表达的影响

目的:观察脂多糖(LPS)诱发的大鼠脊髓背角星形胶质细胞趋化因子CXCL1和CCL2的表达及释放,分析Toll样受体2(TLR2)以及Toll样受体4(TLR4)的作用。方法:培养新生SD大鼠(<3d)脊髓背角星形胶质细胞,免疫荧光鉴定纯度达95%之后分为空白对照组、LPS处理组、TAK-242+LPS处理组、LPS-RS+LPS处理组。在LPS(1μg/ml)作用下,采用real time RT-PCR法检测SD大鼠(<3d)脊髓背角星形胶质细胞CXCL1和CCL2 mRNA表达;Western Blot用于检测胶质纤维酸性蛋白(GFAP)、TLR2、TLR4、CXCL1以及CCL2表达;ELISA检测CXCL1和CCL2释放。结果:与正常对照组相比,LPS作用6 h,背角星形胶质细胞CXCL1和CCL2在mRNA和蛋白水平的表达均上调(P<0.05),CXCL1和CCL2释放增加(P<0.05)。LPS刺激CXCL1和CCL2表达和释放增加的效应可以被TLR4受体拮抗剂TAK-242(50 nmol)以及TLR2/TLR4受体拮抗剂LPS-RS(500 ng/ml)明显阻断(P<0.05)。与正常组相比,LPS刺激星形胶质细胞GFAP、TLR2、TLR4和核转录因子-κBp65(NF-κBp65)表达上调(P<0.05),该效应亦可被TAK-242和LPS-RS所阻断(P<0.05)。此外,与LPS处理组相比,TAK-242预处理背角星形胶质细胞可明显抑制LPS诱发的TLR2表达上调。结论:TLR4/NF-κB信号可能参与了LPS诱导的培养的大鼠脊髓星形胶质细胞趋化因子CXCL1和CCL2表达上调和释放增加。     

脊髓小胶质细胞P2X_4受体在rrTNF诱导的病理性疼痛中的作用

目的:研究P2X4受体在坐骨神经周围给予重组大鼠TNF-α(recombinant rat TNF-α,rr TNF)引起的机械痛敏中的作用。方法:采用雄性SD大鼠(180~200 g),Western blot检测坐骨神经周围给予rr TNF后3 d、7d和14 d脊髓背角P2X4受体的表达水平,免疫荧光双染观察脊髓背角P2X4受体的表达部位;在坐骨神经周围给予rr TNF的大鼠前鞘内注射TNP-ATP,行为学检测大鼠50%机械撤足阈值的变化,Western blot检测脊髓背角TNF-α的表达是否发生变化。结果:与对照组相比,坐骨神经周围给予rr TNF(100 ng/L)后3 d、7 d和14 d同侧脊髓背角P2X4受体的表达水平明显升高(P0.01);P2X4受体只表达于小胶质细胞中,神经元和星形胶质细胞中没有表达。坐骨神经周围给予rr TNF的大鼠前鞘内注射TNP-ATP可防止rr TNF诱导的机械痛敏并抑制脊髓背角TNF-α的上调。结论:小胶质细胞P2X4受体可能通过上调脊髓背角的TNF-α介导rr TNF诱导的机械痛敏。     

鞘内注射MRS2211对慢性坐骨神经结扎大鼠脊髓背角P2X_4受体和P38MAPK表达的影响

目的:观察鞘内注射P2Y13受体阻断剂MRS2211对慢性坐骨神经结扎(CCI)大鼠热痛阈及脊髓背角P2X4受体、P38MAPK表达变化的影响,探讨脊髓P2Y13受体在神经病理性疼痛中的作用。方法:成年SD大鼠随机分为3组(n=8):假手术组、CCI模型组(鞘内注射生理盐水)、MRS2211(100 pmol/L)处理组(CCI+鞘内注射MRS2211)。CCI模型组及MRS2211处理组大鼠均于鞘内置管7 d之后行慢性坐骨神经结扎,连续14 d鞘内注射生理盐水、MRS2211(100 pmol/L),2次/d。分别在术前1 d、术后第1,3,5,7,10,14 d测定给药1h后热缩足潜伏期(TWL);分别在第7,14 d处死大鼠,取脊髓背角做Western Blot检测,观察背角P2X4受体和P38MAPK的表达变化。结果:与假手术组相比,CCI组大鼠第1,3,5,7,10,14 d TWL明显缩短(P0.01);与CCI组相比,MRS2211处理组大鼠术后第1,3,5,7,10,14 d TWL明显延长(P0.05)。Western Blot结果观察到,与假手术组相比,CCI组第7 d P2X4受体表达上调(P0.05),在第14 d P2X4受体表达上调更为明显(P0.05);与假手术组相比,CCI组第7 d P38MAPK表达明显上调(P0.05),在第14 d P38MAPK表达有所下降,但与假手术组相比仍具有统计学意义(P0.05);与CCI组相比,MRS2211处理组大鼠第7 d后背角P38MAPK表达上调明显减弱(P0.05),但在第14 d P38MAPK表达有所上升,但与CCI组相比仍具有统计学意义(P0.05);此外,鞘内注射MRS2211并不影响CCI大鼠背角P2X4受体表达变化。结论:鞘内注射P2Y13受体拮抗剂MRS2211可以明显抑制CCI大鼠热痛敏症状和脊髓背角P38MAPK表达的上调,但并不影响CCI大鼠P2X4受体表达变化。这提示MRS2211可以抑制小胶质细胞P38MAPK活化但不影响小胶质细胞P2X4受体表达,这可能是其在脊髓水平发挥镇痛作用的机制之一。     

星形胶质细胞胞质[Ca~(2+)]i振荡的研究进展

胶质细胞通过自发产生钙离子振荡 ,继而引起Ca2 + 浓度在时空上的波浪式变化形成 [Ca2 + ]i振荡。本文从星形胶质细胞内的Ca2 + 信号通路、神经元———星形胶质细胞之间双向的信息交流和星形胶质细胞自发的 [Ca2 + ]i波等三方面综述了 [Ca2 + ]i振荡在星形胶质细胞功能上的可能作用和研究进展。     

骨癌痛大鼠NRG1-ErbB2和脊髓胶质细胞纤维酸性蛋白的表达

目的观察NRG1、Erb B2和脊髓星形胶质细胞在骨癌痛大鼠中的表达。方法雌性SD大鼠,随机分为2组,每组48只。Sham组(假手术组)和骨癌痛模型(CIBP,胫骨内注射Walker256乳腺癌细胞)组。于注射瘤细胞前和后6、14、21d取出L4~L6节段脊髓,利用免疫组化方法明确星形胶质细胞标记物胶质细胞纤维酸性蛋白(GFAP)在脊髓背角的分布及表达,q RT-PCR检测NRG1、Erb B2和GFAP m RNA的变化。结果 CIBP组大鼠接种瘤细胞后14天,GFAP蛋白和m RNA表达水平明显高于Sham组,并持续至接种后21d(0.05),星形胶质细胞的胞体变得肥大。接种瘤细胞后6d大鼠脊髓NRG1m RNA和Erb B2 m RNA表达水平比Sham组显著增加,持续至接种瘤细胞后21d(0.05)。结论髓背角NRG1、Erb B2参与了骨癌痛,可能与星形胶质细胞活化相关。     

H2O2通过ERK通路抑制绒毛外细胞滋养层细胞的侵袭能力

目的研究活性氧过氧化氢（H2O2）对绒毛外细胞滋养层细胞（EVCT）侵袭行为的影响及其信号传导机制。方法建立EVCT体外培养模型,利用Transwell细胞侵入系统检测EVCT的体外侵袭作用,应用Western blot法评价细胞外信号调节蛋白激酶（ERK1/2）的活性变化,使用CCK-8测定细胞的生长状况。结果与对照组比较,15μmol/LH2O2和50 μmol/L PD98059均可显著抑制EVCT的侵入指数（分别为43.3±4.7,49.3±7.0）（P〈0.01）,同时降低EVCT的ERK1/2磷酸化水平（P〈0.01）,但并不影响EVCT的细胞活力（P〉0.05）。结论 H2O2可能通过抑制ERK1/2的激活,进而影响EVCT的侵袭行为,参与子痫前期的发病机制。     

Identification and characterization of the BPV-2 L2 protein

The bovine papilloma virus type 2 (BPV-2) L2 open reading frame was cloned into a lambda pL promoter expression vector. This plasmid was shown to express a fusion protein which constituted 75% of the BPV-2 L2 ORF linked to the first 13 N-terminal amino acids of the lambda cll gene product. Antisera generated against this fusion protein were used to identify the L2 gene product as a 64,000-Da protein in BPV-2 virions. Western blot analysis demonstrated that the L2 viral protein was present in full capsids and in small amounts in empty capsids. Densitometer analysis indicated that the L2 protein constituted only 8% of the total L1 + L2 protein content of full capsids. Antisera was also used to demonstrate that the BPV-2 L2 protein is antigenically related to the BPV-1 L2 protein.     

Role of alpha chain-IL-2 complex in the formation of the ternary complex of IL-2 and high-affinity IL-2 receptor

Using anti-Tac (anti-alpha chain) and 2R-B (anti-beta chain) antibodies, we studied the roles of IL-2 receptor subunits (alpha and beta chains) in the formation of IL-2 and high-affinity IL-2 receptor complex, which is the initial event of IL-2 induced T cell growth. High-affinity IL-2 binding which was undetectable in the presence of 2R-B antibody at 4 degrees C became fully detectable when examined at 37 degrees C, which explained the lack of inhibition by 2R-B antibody of IL-2-induced proliferation of the cells expressing high-affinity IL-2 receptor. We further studied the mechanism of the 'reappearance' of high-affinity IL-2 binding in the presence of 2R-B antibody. The addition of IL-2 to the cells preincubated with radiolabeled or fluorescence-labeled 2R-B antibody resulted in a marked decrease in the antibody bound to the cells expressing high-affinity IL-2 receptor at 37 degrees C. This decrease was blocked by the presence of anti-Tac antibody, which inhibited IL-2 binding to alpha chain, but not by 7G7/B6 antibody, which recognized a non-IL-2 binding site of its chain. Furthermore, the decrease in cell-bound 2R-B antibody was not due to the internalization of beta chain-2R-B antibody complex, because the amount of cell-bound Mik-beta3 antibody recognizing a non-IL-2 binding epitope of beta chain remained unchanged, nor to the inhibition by simple competitive binding of IL-2 molecules to beta chain as judged from comparative studies of competitive binding inhibition. Taking these data together, the reappearance of high-affinity IL-2 binding was considered to be caused by the replacement of 2R-B antibody at the IL-2 binding site of beta chain by alpha chain-mediated IL-2, and it was strongly suggested that alpha chain-IL-2 complex has a key role in the formation of the ternary complex of IL-2 and high-affinity IL-2 receptor. alpha chain may function as a dimension converter of IL-2 to effectively deliver IL-2 molecules to a relatively small number of beta chains in the dynamics of the formation of high-affinity IL-2 binding in T cells.     

On the origin of the human influenza virus subtypes H2N2 and H3N2

The RNA of the human influenza virus Singapore (H2N2) strain has been labeled in vivo by phosphorus-32 and separated by polyacrylamide gel electrophoresis into eight segments, which were correlated to the corresponding gene functions and/or proteins. The base sequence homology between the individual genes (segments) of the H2N2 virus and those of different influenza A strains has been determined by molecular hybridization. Segments 1, 5, 7, and 8 of the Singapore strain exhibit a base sequence homology of almost 100% as compared to the FM1 strain (HlNl), while the homology between the other segments is significantly lower (24–76%). For the Singapore and Hong Kong (H3N2) strains all segments except that coding for the hemagglutinin (HA, 24%) exhibit a homology close to 100%. The ³²P-labeled segment 4 (HA-gene) of the avian influenza A strain duck Ukraine (Hav7Neg2) shows a homology of 92% to Hong Kong, while the homology of at least two other segments is significantly lower. These results are taken as an indication that the H2N2 subtype is derived from the HlN1 subtype by a recombination event retaining four H1N1 segments, while the other four segments are gained from another yet unknown strain. The H3N2 subtype is presumably derived from a H2N2 subtype, retaining seven segments of the H2N2 subtype, while the gene coding for the HA is obtained from the duck Ukraine or another highly related strain.     

2-Perbromomethyl-2-oxazoline: a novel trifunctional initiator for the ring-opening polymerization of 2-methyl-2-oxazoline

Polymerization of 2-methyl-2-oxazoline was carried out using a trifunctional initiator, 2-perbromomethyl-2-oxazoline. The degree of polymerization (DP) of the resulting polymer was very close to the feed mole ratio of the monomer to initiator. The number-average molecular weight M?_n increased linearly with conversion, indicating the living nature of the propagating chain end. ¹H NMR and end-group analyses results are consistent with the proposal that the polymer possesses a star-shaped structure.     

IL－2和sIL－2R在哮喘发病中的意义探讨

为了探讨ＩＬ－２和ｓＩＬ－２Ｒ在哮喘发病中的意义，对３６例哮喘患者外周血单个核细胞（ＰＢＭＣ）诱生ＩＬ－２水平和血浆ｓＩＬ－２Ｒ水平进行了检测，同时以支气管炎患者与正常人作对照。结果表明，ＰＢＭｃ诱生的ＩＬ－２活性哮喘组高于正常对照组（ｐ＜０．０５）；血浆ｓＩＬ－２Ｒ水平哮喘组高于支气管炎和正常组（ｐ＜０．０１），后两者差异无显著性。以上结果表明，哮喘发病中存在着Ｔ细胞的活化，ＩＬ－２／ＩＬ－２Ｒ在哮喘发病中起作用。     

Investigation of the solubility and ion release in the glass system K2O-Na2O-CaO-P2O5

Glasses from the quaternary glass system K2O-Na2O-CaO-P2O5 were produced by standard glass forming techniques. The compositions were limited by fixing the P2O5 at 45 mol%, fixing the CaO content at either 20, 24 or 28 mol%. The K2O and Na2O made up the residual varying from 0 to 25 mol% K2O. General trends showed that with increasing CaO content, the glasses showed a decrease in solubility as expected. For a single system of fixed CaO content, with increasing K2O content, there was an increase in solubility. This was seen at all three CaO contents. All the glasses showed an initial increase in pH followed by a gradual decrease with time and this was accounted for by the initial release of Na+ ions into solution. For the ion release curves, for all fixed CaO contents, the glass with 0 mol% K2O showed the lowest Ca2+ release. This was accounted for as being due to the low solubility compared to the K2O containing glasses. The Na+ release appeared anomalous, as it was higher than all the K2O containing glasses. Even though the glasses with 0 mol% K2O showed the lowest solubility, the amount of Na+ contained in the glass was high, hence the high levels of release.     

Quantitative structure-activity relationship analysis of the cation permeability of the P2X2 channel

The membrane-embedded, ligand-gated P2X glycoprotein receptor is a monovalent-bivalent cation channel that is activated by physiological concentrations of extracellular ATP. A quantitative structure-activity relationship (QSAR) analysis was developed to model the cation permeability of the P2X2 channel and its mutants. As chemical properties, the helix-coil equilibrium constants and the distribution coefficients of the system octanol/water at pH 7.4 were applied and modified (sliding windows) according to Eroshkin et al. (Comput. Appl. Biosci., 1995, 11, 49-44). The results were visualized by a dimeric P2X2 channel construct. The results support the hypothesis that residues which put into the cavity and contribute to hydrogen bonding forces are involved to a control of the transport of hydrated cations through the P2X2 channel. The model may be useful to develop P2X2 receptor antagonists.