TGF-β1对结直肠癌细胞株侵袭转移及IL-22表达的影响

目的 探讨转化生长因子β1（TGF-β1）对结直肠癌细胞株侵袭转移及白细胞介素22（IL-22）蛋白表达的 影响。方法 以结直肠癌HCT116细胞株为研究对象,以不同浓度（0、5、10、15、20、30、50 μg/L）TGF-β1处理24、48 h 后,CCK-8法检测结直肠癌HCT116细胞体外增殖情况;将结直肠癌HCT116细胞株分为对照组和10 μg/L TGF-β1 处理组。Transwell侵袭迁移实验和划痕实验检测TGF-β1对HCT116细胞侵袭迁移能力的影响;采用RT-PCR检测 TGF-β1对HCT116细胞TGF-β1、IL-22 mRNA表达的影响;免疫细胞化学染色和Western blot 检测HCT116细胞中 TGF-β1、IL-22、信号转导和转录激活因子3（STAT3）、E-钙黏蛋白（E-cadherin）表达水平。结果 CCK-8结果显示, 0、5、10、15、20、30、50 μg/L TGF-β1 溶液刺激 24、48 h 后,不同 TGF-β1 浓度处理组结直肠癌 HCT116 细胞光密度 （OD）值差异均无统计学意义（均P＞0.05）。10 μg/L TGF-β1处理HCT116细胞48 h后,细胞侵袭能力、迁移能力和 迁移距离均明显升高（均P＜0.01）;TGF-β1处理组TGF-β1 mRNA表达水平明显高于对照组,而IL-22 mRNA表达水 平明显低于对照组（均P＜0.01）;免疫细胞化学染色和Western blot结果显示,TGF-β1处理组TGF-β1、STAT3蛋白表 达水平明显高于对照组,而IL-22、E-cadherin蛋白表达水平明显低于对照组（均P＜0.05）。结论 TGF-β1可能促进 HCT116细胞侵袭和迁移,但对HCT116细胞的增殖影响不明显,结直肠癌HCT116细胞中TGF-β1可能抑制IL-22蛋 白的表达。     

Ski在全反式维甲酸抑制TGF-β1诱导的系膜细胞增殖中的作用

【摘要】目的 探讨全反式维甲酸（ATRA）对转化生长因子(TGF)-β1诱导的大鼠系膜细胞增殖及Ski表达的影响。方法 不同浓度ATRA预处理大鼠HBZY-1系膜细胞（为各剂量ATRA组）24 h后再加TGF-β1 (10 μg/L)培养24 h。 CCK-8法检测细胞增殖情况;Real-time PCR法检测Ski mRNA的表达;Western blot检测Ski蛋白的表达;激光共聚焦荧光显微镜检测Ski蛋白的亚细胞定位。并与正常对照组及TGF-β1组比较。结果 与正常对照组相比,TGF-β1组系膜细胞增殖明显,且Ski mRNA及蛋白表达升高(P < 0.05);与TGF-β1 组相比,ATRA能够呈剂量依赖性地抑制 TGF-β1的促增殖作用,ATRA 10 μmol/L组Ski mRNA及蛋白表达量明显增高。ATRA组Ski蛋白主要定位于大鼠系膜细胞核,其细胞核荧光信号强度较TGF-β1组明显增强,细胞浆中荧光信号强度较TGF-β1组减弱。结论 ATRA可通过上调大鼠系膜细胞Ski表达,抑制其向核外转位,从而抑制TGF-β1诱导的系膜细胞增殖。     

脂多糖对小胶质细胞血管内皮生长因子表达的影响

摘要： 目的 探讨脂多糖（LPS）是否能够通过低氧诱导因子-1α（HIF-1α）调节小胶质细胞血管内皮生长因子（VEGF） 的表达。方法 培养 BV2 小胶质细胞系, 分为 4 组： 对照组、 LPS （100 µg/L） 刺激组、 LRS 干预组 （LPS 100 µg/L及脂多糖拮抗剂 200 µg/L）, HIF-1α抑制剂干预组 （LPS 100 µg/L 及 FM19G11 10 mmol/L）。分别采用免疫荧光、 Western blot、 ELISA 检测 VEGF 和 HIF-1α 的表达情况。结果 与对照组比较, LPS 可显著增加 BV2 细胞 VEGF 表达, 脂多糖拮抗剂可明显抑制 LPS 的这一作用。HIF-1α的表达在 LPS 刺激 8 h 后明显增加。HIF-1α抑制剂 FM19G11 可减少 LPS 引起的 BV2 细胞 VEGF 表达增加。结论 LPS 促进小胶质细胞 VEGF 的表达, HIF-1α参与这一调节过程。     

白藜芦醇对H2O2 及TGF-β2诱导人小梁网细胞的影响及机制探讨

摘要： 目的 观察过氧化氢 （H2O2 ） 及转化生长因子 （TGF） -β2 诱导人小梁网细胞 （HTMCs） 后对纤维连接蛋白（FN）、 胶原蛋白 1 型 （COL1）、 核因子 （NF） -κB P65 蛋白和白细胞介素 （IL） -1β基因表达的影响及白藜芦醇 （RSV） 的干预作用。方法 （1） 选取汇合度 70%～80%的 HTMCs 分为 5 组。实验组于无血清培养基中分别加入浓度为 150、 300、 450、 800 μmol/L 的 H2O2 处理, 对照组的培养基中不加 H2O2。Western blot 法检测各组 FN、 COL1、 NF-κB P65、 NF-κB P65 磷酸化 （P-NF-κB P65） 蛋白的表达, 实时定量 PCR 法检测 IL-1β基因的表达。（2） HTMCs 细胞分为 3 组。对照组以不含 H2O2 及 RSV 的无血清培基处理, H2O2 组以 300 μmol/L 的 H2O2 处理, H2O2+RSV 组同时加入 300 μmol/L 的 H2O2 及 25 μmol/L 的 RSV 处理。检测各组上述蛋白和基因的表达情况。免疫荧光检测各组 NF-κB P65 在 HTMCs 中的定位。（3） HTMCs 细胞分为 3 组。对照组以不含 TGF-β2 及 RSV 的无血清培基处理, TGF-β2 组以 5 μg/L 的 TGF-β2 处理, TGF-β2+RSV 组为同时加入 5 μg/L 的 TGF-β2 及 25 μmol/L 的 RSV 处理。检测各组上述蛋白和基因的表达情况。结果 （1） 与对照组比较, 150、 300、 450、 800 μmol/L 组 FN 和 P-NF-κB P65 蛋白表达水平均增高, 300、 450、 800 μmol/L 组 COL1 蛋白和 IL-1β基因表达水平增高 （P < 0.05）, 其他指标比较差异均无统计学意义。（2） H2O2 组较对照组 FN、 COL1、 P-NF-κB P65 蛋白和 IL-1β基因表达水平均增高, 而 H2O2+RSV 组较 H2O2 组上述指标均降低, H2O2+RSV 组较对照组仅 IL-1β降低 （P < 0.05）。对照组仅细胞质表达 NF-κB P65, H2O2 组细胞胞质及核中均有 NF-κB P65 表达, 且核中表达较多; H2O2+RSV 组细胞胞质中表达 NF-κB P65 较核中多。（3） TGF-β2 组较对照组 FN、 COL1、 P-NF-κB P65 的蛋白和 IL-1β基因水平表达均增高 （P < 0.05）, TGF-β2+RSV 组较 TGF-β2 组上述指标均降低 （P < 0.05）。 结论 H2O2 和 TGF-β2 能上调 HTMCs 的 FN、 COL1、 P-NF-κB P65 蛋白及 IL-1β基因的表达, 可能参与青光眼的发生发展过程。RSV 能抑制H2O2和 TGF-β2对HTMCs 的影响, 对青光眼发挥一定的保护作用。     

脂肪因子Apelin-13对3T3-L1脂肪细胞水通道蛋白7基因表达的影响

目的 探讨脂肪因子Apelin-13对3T3-L1脂肪细胞水通道蛋白7（AQP7）基因表达的影响.方法 体外培养3T3-L1脂肪细胞,以油红O染色鉴定为成熟脂肪细胞后,分为阴性对照组（无干预）,不同浓度（10^-9、10^-8、10^-7、10^-6nmol/L） Apelin-13干预组（均干预24 h）,阳性对照组（10^-5 nmol/L罗格列酮干预24 h）和10^-7 nmol/L Apelin-13干预不同时间（0、12、24、36、48 h）组.用反转录-聚合酶链反应检测各组细胞AQP7 mRNA表达水平.结果 阴性对照组、10^-9、10^-8、10^-7、10^-6 nmol/L Apelin-13和阳性对照组AQP7表达水平分别为（0.22±0.02）、（0.29±0.07）、（0.36±0.05）、（0.43±0.05）、（0.31±0.06）、（0.32±0.08）,阳性对照组与阴性对照组之间差异有统计学意义（P＜0.05）;与阴性对照组比较,10^-8、10^-7 nmol/L Apelin-13能明显刺激AQP7 mRNA表达（P ＜0.05）;10^-8、10^-7 nmol/L Apelin-13组与阳性对照组比较,10^-7 nmol/L Apelin-13能明显刺激AQP7 mRNA表达（P＜0.05）;10^-8、10^-7 nmol/L Apelin-13组间差异无统计学意义.在时间组中,10^-7 nmol/L Apelin-13的0、12、24、36、48 h各组灰度比值分别为（0.27±0.09）、（0.43±0.07）、（0.55±0.10）、（0.42±0.08）、（0.33±0.09）,12、24、36 h组AQP7 mRNA表达较0h组能明显刺激AQP7 mRNA表达（P＜0.05）,作用24 h表达最高;但12、24、36h3组之间AQP7mRNA表达差异无统计学意义.结论 Apelin-13在一定程度上能增加3T3-L1脂肪细胞AQP7 mRNA表达的水平,并分别以10^-7 nmol/L和24 h为最佳作用浓度和时间.     

内源性孤啡肽通过调节β1肾上腺素能受体对大鼠缺血性心律失常的影响

目的 探讨内源性孤啡肽（N/OFQ）对大鼠缺血性心律失常的影响以及心肌细胞β1肾上腺素能受体（β1-AR）在其中的作用。方法 采用结扎左冠状动脉前降支（冠脉）的方法制备大鼠急性心肌缺血模型。将60只大鼠按随机数字表法分为3组，即假手术组（Sham组）、冠脉结扎组（CAO组）和孤啡肽受体拮抗剂（UFP-101）预处理组（U+CAO组），每组20只。3组大鼠分别在冠脉结扎后15 min和1 h 2个时间点各处死10只大鼠。记录心电数据，采用Western blot法分别检测心肌细胞膜以及全细胞β1-AR的表达，RT-qPCR法检测β1-AR mRNA的表达。结果 与Sham组比较，CAO组出现缺血性心律失常，且主要集中在冠脉结扎后15 min内，UFP-101预处理显著降低心律失常发生。15 min 时：与 Sham 组比较，CAO 组全细胞 β1-AR、β1-AR mRNA 表达下调，而细胞膜 β1-AR 上调（均 P＜0.05），U+CAO组全细胞β1-AR蛋白及其mRNA表达无统计学意义（均P＞0.05），而细胞膜β1-AR下调（P＜0.05）；与CAO组比较，U+CAO组全细胞β1-AR蛋白及mRNA表达上调，而细胞膜β1-AR下调（P＜0.05）。1 h时：与Sham组比较，CAO组和U+CAO组全细胞β1-AR蛋白及mRNA表达上调，而细胞膜β1-AR下调（均P＜0.05）。结论 内源性N/OFQ可上调心肌细胞膜β1-AR参与大鼠缺血性心律失常过程。     

MSCs共培养抗ARPE-19细胞氧化应激的作用研究

目的探讨MSCs共培养抗ARPE-19细胞的氧化应激作用。方法常规培养人RPE细胞系ARPE-19细胞,分为正常组、H_2O_2组和共培养组;通过检测细胞内超氧化物气化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)及丙二醛(MDA)水平变化,研究分析MSCs共培养抗ARPE-19细胞氧化应激作用。结果 H_2O_2诱导的氧化应激能显著降低SOD和GSH-Px水平,并提高MDA水平;而MSCs共培养预能显著逆转这种变化,以上差异均具有统计学意义(P<0.05)。结论 MSCs共培养有抗H_2O_2诱导的人视网膜上皮细胞氧化应激作用。     

艾塞那肽对人舌鳞癌SCC-25细胞增殖、侵袭及凋亡的影响

摘要： 目的 探讨艾塞那肽对人舌鳞癌 SCC-25 细胞增殖、 侵袭能力以及凋亡相关指标的影响。方法 体外培养 SCC-25 细胞, Western blot 检测 SCC-25 细胞中胰高血糖素样肽 1 受体（GLP-1R）表达。实验分 4 组： 对照组、 1、 10 和 100 nmol/L 艾塞那肽处理组。培养 24 h、 48 h 和 72 h 后 MTT 法检测各组细胞增殖能力, Transwell 实验检测各组细胞侵袭能力。Western blot 检测基质金属蛋白酶（MMP） -2、 Caspase-3 和 p38 丝裂原活化蛋白激酶（Phosphop38 MAPK）表达。结果 SCC-25 细胞表达 GLP-1R。与对照组相比, 艾塞那肽处理组细胞存活率及侵袭率明显降低（P < 0.05）, MMP-2 蛋白表达降低（P < 0.05）, Caspase-3 蛋白表达明显升高（P < 0.05）; 各指标变化呈现艾塞那肽浓度和时间依赖性。10 nmol/L 艾塞那肽处理组 24 h 后 Phospho-p38 MAPK 表达升高（P < 0.05）。结论 艾塞那肽可抑制 SCC-25 细胞增殖和侵袭, 且可能通过促进 Phospho-p38 MAPK 和 Caspase-3 的表达诱导细胞凋亡。     

重度颅脑外伤病人血清T细胞激活性低分泌因子、γ-干扰素诱导蛋白10表达及其预后相关性

目的 探究重度颅脑外伤病人血清T细胞激活性低分泌因子（RANTES）、γ-干扰素诱导蛋白10(IP-10)水平及其与预后的关系。方法 选取2016年1月至2019年7月中国人民解放军第四军医大学第二附属医院诊治的颅脑外伤病人174例进行研究,根据格拉斯哥昏迷评分（GCS）将病人分为轻度组（n=58例）、中度组（n=58例）、重度组（n=58例）,并选取同期体检健康者58例进行对照研究（健康组）。酶联免疫吸附测定（ELISA）检测血清RANTES、IP-10水平;Pearson法分析重度颅脑外伤病人血清RANTES水平与IP-10的相关性;比较两组不同预后重度颅脑外伤病人血清RANTES、IP-10水平;采用受试者操作特征曲线（ROC）评价血清RANTES、IP-10对重度颅脑外伤病人预后的评估价值。结果 颅脑外伤病人血清RANTES[(1.36±0.38)μg/L、（1.68±0.43）μg/L、（2.06±0.60）μg/L]、IP-10[(247.49±54.45)ng/L、（290.53±62.76）ng/L、（362.18±68.82）ng/L]水平均显著高于健康者（0.88±...     

肿瘤相关巨噬细胞通过激活IGF-1R信号通路诱导三阴性乳腺癌细胞对白蛋白紫杉醇耐药的研究

目的 探讨肿瘤相关巨噬细胞（TAM）对三阴性乳腺癌（TNBC）细胞白蛋白紫杉醇（Nab-PTX）化疗敏感性的影响及作用机制。方法 构建并鉴定TAM模型；通过Transwell小室共培养法建立TAM与TNBC细胞系MDAMB-231细胞共培养模式，分为对照组（MDA-MB-231细胞及空白小室）、Nab-PTX组（MDA-MB-231细胞、空白小室及0.5 nmol/L Nab-PTX）、TAM组（MDA-MB-231细胞、含M2型巨噬细胞的小室）、TAM+Nab-PTX组（MDA-MB-231细胞、含M2型巨噬细胞的小室及0.5 nmol/L Nab-PTX）、胰岛素样生长因子1受体（IGF-1R）抑制剂组（MDA-MB-231细胞、含M2型巨噬细胞的小室、0.5 nmol/L Nab-PTX及4 nmol/L IGF-1R抑制剂Linsitinib）;CCK-8法检测各组细胞增殖情况；流式细胞术检测细胞凋亡；实时荧光定量PCR(q PCR)检测多药耐药蛋白（MDR）1和胱天蛋白酶（Caspase）-3mRNA水平；Western blot检测IGF-1R信号通路关键蛋白表达。结果 T...     

Adenosine A1 receptors modulate anxiety in CD1 mice

The effect of the selective adenosine A₁ receptor agonist 2-chloro-N ⁶-cyclopentyladenosine (CCPA) was investigated in CD1 mice by the elevated plus-maze and the light/dark test, two models for measuring anxiety in rodents. CCPA, administered IP, had an anxiolytic effect at 0.3 nmol/kg in the elevated plus-maze and at 1 nmol/kg in the light/dark test. Brain levels of 22 nM were found after administration of 100 nmol/kg CCPA, as measured by ex vivo binding experiments. These values are consistent with the occupancy of adenosine A₁ but not A₂ receptors by CCPA, and suggest that the anxiolytic-like action of CCPA may be mediated by centrally located adenosine A₁ receptors. Both CPT, a selective adenosine A₁ receptor antagonist, and IBMX, a non-selective adenosine antagonist, had an anxiogenic effect in the two tests. It is thus possible that purinergic neurons may be involved in the tonic modulation of affective state in mice. Received: 4 March 1997/Final version: 4 October 1997     

MgCl2和Gpp（NH）p对腺苷A1受体激动剂和拮抗剂结合的作用比较

AIM: To investigate modulation of antagonist and agonist binding to adenosine A1 receptors by MgCI2 and 5'-guanylimidodiphosphate (Gpp(NH)p) using rat brain membranes and the A1 antagonist [^3H]-8-cyclopentyl-1,3-dipropylxanthine ([^3H]DPCPX) and the A1 agonist [^3H]-2-chloro-N^6-cyclopentyladenosine ([^3H]CCPA). METHODS:Parallel saturation and inhibition studies were performed using well-characterised radioligand binding assays and aBrandel Cell Harvester. RESULTS: MgCI2 produced a concentration-dependent decrease (44%), whereasGpp(NH)p increased [^3H]DPCPX binding (19%). In [^3H]DPCPX competition studies, agonist affinity was 1.5-14.6-fold higher and 4.6-10-fold lower in the presence of l0 mmol/L MgCl2 and l0μmol/L Gpp(NH)p respectively;antagonist affinity was unaffected. The decrease in agonist affinity with increasing Gpp(NH)p concentrations was due to a reduction in the proportion of binding to the high affinity receptor state. In contrast to [^3H]DPCPX, MgCl2produced a concentration-dependent increase (72%) and Gpp(NH)p a decrease (85%) in [^3H]CCPA binding.Using [^3H]CCPA, agonist affinities were 5-17-fold higher than those for [^3H]DPCPX, consistent with binding onlyto the high affinity receptor state. Agonist affinity was 1.3-10.5-fold higher and 2.4-4.7-fold lower on addingMgCl2 or Gpp(NH)p respectively; antagonist affinities were as for [^3H]DPCPX. CONCLUSION: The inconsistencies surrounding the effects of MgCl2 and guanine nucleotides on radioligand binding to adenosine A1 receptorswere systematically examined. The effects of MgCl2 and Gpp(NH)p on agonist binding to A1 receptors are consistent with their roles in stimulating GTP-hydrolysis at the G-protein α-subunit and in blocking formation of the highaffinity agonist-receptor-G protein complex.     

2-Chloro-N6-[3H]cyclopentyladenosine ([3HCCPA) —a high affinity agonist radioligand for A1 adenosine receptors

Summary The tritiated analogue of 2-chloro-N⁶-cyclopentyladenosine (CCPA), an adenosine derivative with subnanomolar affinity and a 10000-fold selectivity for A₁ adenosine receptors, has been examined as a new agonist radioligand. [³H]CCPA was prepared with a specific radioactivity of 1.58 TBq/mmol (43 Ci/mmol) and bound in a reversible manner to A₁ receptors from rat brain membranes with a high affinityK _D-value of 0.2 nmol/l. In the presence of GTP aK _D-value of 13 nmol/l was determined for the low affinity state for agonist binding. Competition of several adenosine receptor agonists and antagonists for [³H]CCPA binding to rat brain membranes confirmed binding to an A₁ receptor. Solubilized A1 receptors bound [³H]CCPA with similar affinity for the high affinity state. At solubilized receptors a reduced association rate was observed in the presence of MgCl₂, as has been shown for the agonist [³H]N⁶-phenylisopropyladenosine ([³H]PIA). [³H]CCPA was also used for detection of A₁ receptors in rat cardio myocyte membranes, a tissue with a very low receptor density. A K_D-value of 0.4 nmol/l and aB _max-value of 16 fmol/ mg protein was determined in these membranes. In human platelet membranes no specific binding of [³H]CCPA was measured at concentrations up to 400 nmol/l, indicating that A2 receptors did not bind [³H]CCPA. Based on the subnanomolar affinity and the high selectivity for A₁ receptors [³H]CCPA proved to be a useful agonist radioligand for characterization of A₁ adenosine receptors also in tissues with very low receptor density.Abbreviations CHA N⁶-cyclopenyadenosine - CPA N⁶-cy-clopentyladen,osine - CCPA 2-chloro-N⁶-cyclopentyladenosine - CCCPA 2-chloro-5-chloro-5-deoxy-N⁶-cyclopentyladenosine; - CHAPS 3-[3-(cholamidopropyl)dimethylammonio]-1-propanesulfonate - DPCPX 8-cyclopentyl-1,3-dipropylxanthine - NECA N-ethylcarboxamidoadenosine - PEI polyethylenimine - PIA N⁶-phenylisopropyladenosine Send offprint requests to K.-N. Klotz at the above address     

Preliminary Investigation into the Expression of Proton-Coupled Oligopeptide Transporters in Neural Retina and Retinal Pigment Epithelium (RPE): Lack of Functional Activity in RPE Plasma Membranes

Purpose. To determine the expression and functional activity of proton-coupled oligopeptide transporters (POT) in retinal pigment epithelial (RPE) cells. Methods. RT-PCR was used to probe the presence of POT mRNA in freshly isolated bovine RPE (BRPE) and human RPE (HRPE) cells, a human RPE cell line (ARPE-19), and human and bovine neural retina. [¹⁴C]GlySar uptake was used to characterize POT activity in cultured ARPE-19 cells and freshly isolated BRPE cell sheet suspensions. Results. PHT1 mRNA was expressed in BRPE, HRPE, ARPE-19, and bovine and human neural retina. In contrast, PEPT2 and PHT2 were expressed only in bovine and human retina, and PEPT1 could not be detected. GlySar exhibited a linear uptake over 6 h at pH values of 6.0 and 7.4, with greater uptake at pH 7.4 (p < 0.01). GlySar uptake did not exhibit saturability (5-2000 M) and was unchanged when studied in the presence of 1 mM L-histidine. In contrast, GlySar uptake was significantly decreased when studied at 4°C or in the presence of endocytic inhibitors at 37°C (p < 0.01). Studies in BRPE cell sheet suspensions validated the results obtained in ARPE-19 cells and strongly suggested the absence of POT on the apical and basolateral membranes of RPE. Conclusions. PHT1 mRNA is present in native bovine and human RPE and a human RPE cell line. However, the data argue against PHT1 being expressed on plasma membranes of RPE. Overall, GlySar appears to be taken up by RPE cells via a low-affinity, endocytic process.     

Modulating effect of adenosine deaminase on function of adenosine A1 receptors

AIM: To study the modulating effect of adenosine deaminase (ADA) on the adenosine A1 receptor (A1R) in HEK293 cells stably expressing the human A1R. METHODS: cDNA was amplified by RT-PCR using total RNA from human embryo brain tissue as the template. The PCR products were subcloned into the plasmid pcDNA3 and cloned into the plasmid pcDNA3.1. The cloned A1R cDNA was sequenced and stably expressed in HEK293 cells. The modulating effect of adenosine deaminase on A1R was studied by using [3H]DPCPX binding assay and an intracellular calcium assay. RESULTS: HEK293 cells stably expressing human A1R were obtained. Saturation studies showed that the K(D) value and B(max) value of [3H]DPCPX were 1.6+/-0.2 nmol/L and 1.819+/-0.215 nmol/g of protein respectively, in the absence of ecto-ADA respectively, and 1.3+/-0.2 nmol/L and 1.992+/-0.130 nmol/g of protein in the presence of ecto-ADA respectively, suggesting that the K(D) value and B(max) value of [3H]DPCPX were unaffected by ecto-ADA. In the case of [3H]DPCPX competition curves obtained from intact cells or membranes, A1R agonist CCPA/[3H]DPCPX competition curve could be fitted well to a one-site model in the absence of ecto-ADA and a two-site model in the presence of ecto-ADA with a K(H) value of 0.74 (0.11+/-4.8) nmol/L (intact cells) or 1.8 (0.25+/-10) nmol/L (membrane) and a K(L) value of 0.94 (0.62+/-1.41) micromol/L (intact cells) or 0.77 (0.29+/-0.99) micromol/L (membrane). The K(L) value is not significantly different from the IC50 value of 0.84(0.57+/-1.23) micromol/L (intact cells) or 0.84 (0.63+/-1.12) micromol/L (membrane) obtained in the absence of ecto-ADA. Similar results were obtained from the CPA/[3H]DPCPX competition curve in the absence or presence of ecto-ADA on intact cells or membranes. Intracellular calcium assay demonstrated that the EC50 value of CPA were 10 (5+/-29) nmol/L and 94 (38+/-229) nmol/L in the presence or absence of ecto-ADA, respectively. CONCLUSION: A1R stably expressed in the HEK293 cells display a low affinity for agonists in the absence of ADA and high and low affinities for agonists in the presence of ADA. The presence of ADA may promote the signaling through the adenosine A1 receptor in HEK293 cells.     

1,25（OH）2D3对人血管平滑肌细胞TLR4基因及炎症因子表达的抑制作用

目的探讨1,25(OH)2D3(1,25-dihydroxyvitamin D3)对人主动脉血管平滑肌细胞(human aortic vascular smooth muscle cell,HA-VSMC)果蝇样受体(Toll like receptor 4,TLR4)基因及其下游炎症因子IL-6、IL-8和MCP-1表达的调节作用。方法不同浓度1,25(OH)2D3干预HA-VSMC后,采用实时荧光定量PCR法检测细胞TLR4、IL-6、IL-8、MCP-1mR-NA的表达水平。结果 1,25(OH)2D3在浓度为1~20nmol/L之间抑制TLR4、IL-6、IL-8、MCP-1mRNA水平的表达且具有明显的剂量依赖关系。在浓度为1nmol/L时1,25(OH)2D3下调TLR4和MCP-1mRNA表达的作用最明显,浓度为10nmol/L时,1,25(OH)2D3下调IL-6mRNA表达的作用最明显,浓度为20nmol/L时,1,25(OH)2D3下调IL-8mRNA表达的作用最明显。TLR4、IL-6、IL-8和MCP-1mRNA表达的最大下调幅度分别为对照组的3.08、2.39、3.19、2.23倍(均P<0.05)。结论 1,25(OH)2D3通过下调TLR-4信号抑制了人主动脉血管平滑肌细胞的炎症反应。     

2-Chloro-N(6)-cyclopentyladenosine,adenosine A(1) receptor agonist,antagonizes the adenosine A(3) receptor

The potent adenosine A(1) receptor agonists, N(6)-cyclopentyladenosine (CPA) and 2-chloro-N(6)-cyclopentyladenosine (CCPA), were studied in Chinese hamster ovary (CHO) cells expressing the human adenosine A(3) receptor. CPA, but not CCPA, induced phosphoinositide turnover. CPA inhibited forskolin-stimulated cyclic AMP production (EC(50) value of 242+/-47 nM). CCPA competitively antagonized the effects of agonist Cl-IB-MECA (2-chloro-N(6)-(3-iodobenzyl)-5'-N-methylcarbamoyladenosine) with K(B) value of 5.0 nM. CPA competition curves versus the A(3) antagonist radioligand [3H]PSB-11 (8-ethyl-4-methyl-2-phenyl-(8R)-4,5,7,8-tetrahydro-1H-imidazo[2.1-i]purin-5-one) were right-shifted four-fold by 100 microM GTP, which had no effect on binding of CCPA or the antagonist MRS 1220 (N-[9-chloro-2-(2-furanyl)[1,2,4]triazolo[1,5-c]quinazolin-5-yl]benzene-acetamide). Thus, CCPA is a moderately potent antagonist (K(i)=38 nM) of the human A(3) adenosine receptor.     

Mechanisms of delayed preconditioning with A1 adenosine receptor activation in porcine coronary smooth muscle cells

This study examined the hypothesis that the activation of A1 adenosine receptor (A1AR) induces delayed cellular protection (DCP) in porcine coronary smooth muscle cells (PCSMC). The following groups of cultured PCSMC, subjected to simulated ischemia (SI) at 20 h were studied: (a) SI: with ischemia alone; (b) A1AR agonist chloro-N6-cyclopentyl adenosine (CCPA: CCPA (1 microM) alone; (c) CCPA + PKC inhibitor chelerythrine chloride (CCL): CCPA and 1 microM CCL; (d) CCPA + iNOS inhibitor S-methylthiourea (SMT): CCPA and 100 nM SMT; (e) CCPA + KATP channel blocker Glibenclamide (Glb): CCPA and 50 microM Glb; (f) CCPA + mitochondrial KATP channel blocker 5-hydroxydecanoate (5-HD): CCPA and 100 microM of 5-HD; (g) CCPA + A1AR antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX): CCPA and 1 microM DPCPX. The release of LDH into the medium as well as the amount of LDH remaining in the cells was used as a marker of cellular injury and cell viability. Up-regulation of A1AR, epsilon-PKC, iNOS and HSP 72i was detected through Westem blot analysis. The cellular resistance (%LDH remaining in the cells) acquired by PCSMC due to CCPA (59.42 +/- 1.57) was significantly blocked by CCL: 39.30 +/- 2.03; SMT: 41.37 +/- 1.98; Glb: 47.24 +/- 1.31; 5-HD: 47.69 +/- 1.40 and DPCPX: 42.92 +/- 0.79. CCPA increased the expression of A1AR (1.30 fold), epsilon-PKC (1.20 fold), iNOS (1.50 fold), and HSP 72i (1.70 fold) compared to the controls. CCPA-induced up-regulation of A1AR, epsilon-PKC, iNOS, HSP 72i, and the opening of both mitochondrial and sarcolemmal KATP channels may possibly participate in signaling cascade. Our study suggests that A1AR activation up-regulates iNOS, HSP 72i via epsilon-PKC signaling pathway to activate both mitochondrial and sarcolemmal KATP channels for cellular protection against SI in the cultured PCSMC.     

Signal pathways underlying homocysteine-induced production of MCP-1 and IL-8 in cultured human whole blood

Aim: To elucidate the mechanisms underlying homocysteine (Hcy)-induced chemokine production. Methods: Human whole blood was pretreated with inhibitors of calmodulin (CAM), protein kinase C (PKC), protein tyrosine kinase (PTK), mitogen-activated protein kinase (MAPK), and NF-kB and activators of PPARγ for 60 min followed by incubation with Hcy 100 μmol/L for 32 h. Thelevels of mitogen chemokine protein (MCP)-I and interleukin-8 (IL-8) were determined by enzyme-linked immunosorbant assay (ELISA). Results: Inhibitors of PKC (calphostin C, 50-500 nmol/L and RO-31-8220, 10-100 nmol/L), CaM (W7, 28-280 μmol/L), ERK1/2 MAPK (PD 98059, 2-20 μmol/L), p38 MAPK (SB 203580, 0.6-6μmol/L), JNK MAPK (curcumin, 2-10μmol/L), and NF-kB(PDTC, 10-100 nmol/L) markedly reduced Hcy 100 μmol/L-induced production of MCP-1 and IL-8 in human cultured whole blood, but the inhibitors of PTK(genistein, 2.6-26 μmol/L and tyrphostin, 0.5-5 μmol/L) had no obvious effect on MCP-1 and IL-8 production. PPARγ activators (ciglitazone 30 μmol/L andtroglitazone 10 μmol/L) depressed the Hcy-induced MCP-1 production but not IL-8 production in the cultured whole blood. Conclusion: Hcy-induced MCP-1 and IL-8 production is mediated by activated signaling pathways such as PKC, CaM, MAPK, and NF-kB. Our results not only provide clues for the signal transduction pathways mediating Hcy-induced chemokine production, but also offer a plausible explanation for a pathogenic role of hyperhomocysteinemia in these diseases.