红霉素对支气管上皮细胞细胞外信号调节蛋白激酶1及转录激活蛋白-1的影响

目的探讨红霉素对支气管上皮细胞细胞外信号调节蛋白激酶1(ERK1)及转录激活蛋白-1(AP-1)活性的影响。方法将人支气管上皮细胞(16-HBE)分为4-羟基壬烯醛(4-HNE)组(10μmol/L)和对照组,4-HNE刺激细胞0.5h、2h、4h、8h及12h后,检测磷酸化c-Jun氨基末端激酶(JNK)、p38丝裂素活化蛋白激酶(MAPK)、ERK1/2及AP-1活性的变化,观察MAP激酶1(MEK1)抑制剂PD98059对4-HNE引起的AP-1结合活性的影响;观察红霉素对磷酸化ERK1、AP-1结合活性的影响。结果 4-HNE组在2h、4h、8h及12h各时间段ERK1/β-actin分别为2.1依0.4、1.8依0.4、1.6依0.6、1.3依0.8,对照组分别为4.2依0.2、4.8依0.7、4.4依0.5、4.3依0.6,两组比较差异有统计学意义(均P约0.05)。4-HNE组各时间段AP-1结合活性表达分别为90.6依2.0、85.7依2.2、78.2依2.6、70.6依1.8和64.9依4.8,对照组分别为98.6依2.1、98.7依3.4、100.1依3.8、101.3依4.2和97.4依3.6,两组比较差异有统计学意义(均P约0.05)。PD98059和红霉素可降低4-HNE引起的AP-1结合活性,红霉素增加4-HNE引起的磷酸化ERK1的表达。结论红霉素引起支气管上皮细胞ERK1磷酸化的增加,但可以抑制其AP-1的结合活性,可能与对ERK1/2下游信号传导通路的阻断有关。     

辛伐他汀通过MEK/ERK信号转导通路上调突触素表达

目的研究辛伐他汀(SV)对体外培养大鼠大脑皮层神经元突触素(SYP)的影响及信号转导机制。方法从新生Sprague-Dawley大鼠大脑皮层分离和培养神经元,4 d后分为对照组、SV处理组(2、4、8μmol/L作用48 h)、PD98059处理组和SV+PD98059处理组(先加入10μmol/L阻断剂PD98059作用30 min,再加入10μmol/L SV作用48 h)。应用免疫荧光检测法检测SYP表达,Western blot检测磷酸化丝裂原细胞外激酶(p-MEK)、磷酸化细胞外调节蛋白激酶1(p-ERK1)和磷酸化细胞外调节蛋白激酶2(p-ERK2)水平。结果免疫荧光检测显示,4μmol/L SV可明显增强SYP免疫反应性。Western blot检测显示,8μmol/L SV可显著增高SYP、p-MEK、p-ERK1和p-ERK2水平。应用PD98059可显著降低SV引起的SYP、p-MEK、p-ERK1和p-ERK2水平上调。结论SV可通过激活MEK/ERK信号转导通路上调SYP表达。     

ERK1/2信号通路阻断剂PD98059对慢性高原病患者骨髓有核红细胞中Ras、BRaf、MEK、ERK1/2表达的影响

目的:探讨ERK1/2信号通路阻断剂PD98059对Ras、B型丝/苏氨酸蛋白激酶(BRaf)、丝裂原活化蛋白激酶(MEK)、细胞信号调节激酶1/2(ERK1/2)表达的影响,以期为慢性高原病(chronic mountain sickness,CMS)的基础研究和临床治疗探讨新的途径。方法:选取CMS患者16例,取骨髓液分离单个核细胞,以CD71与CD235a抗体磁珠分选阳性细胞,将细胞分为5组:空白对照组、DMSO溶剂组及PD98059 5、10和20μmol/L组。在低氧条件下培养72 h,应用ELISA法测定培养骨髓有核红细胞上清液中Ras-GTP水平,RT-PCR法测定骨髓有核红细胞中BRaf、MEK、ERK1/2 mRNA的表达,Western blot方法检测骨髓有核红细胞中p-BRaf、p-MEK、pERK1/2蛋白表达。结果:PD98059对各组Ras-GTP的水平无明显影响(P=0.798)。溶剂组与空白对照组相比,BRaf、MEK mRNA的表达水平差异无统计学意义(P=0.826、P=0.298)。与PD98059 20 mol/L比较,其余4组ERK1/2 mRNA的表达水平差异有统计学意义(P=0.001、P=0.002)。溶剂组与空白对照组相比,p-BRaf、p-MEK蛋白的表达差异无统计学意义(P=0.370、P=0.351)。与PD98059 20 mol/L比较,其余4组p-ERK1/2蛋白水平差异有统计学意义(P0.001、P0.007)。结论:PD98059能下调骨髓有核红细胞ERK1/2 mRNA及p-ERK1/2蛋白的表达。Ras/Raf/MEK/ERK 1/2通路是调控CMS骨髓有核红细胞的主要信号传导途径,可能参与了慢性高原病的发病过程。     

ERK1/2信号传导通路介导碱性成纤维细胞生长因子诱导人晶状体上皮细胞中环氧合酶2的表达

背景：碱性成纤维细胞生长因子在各种白内障形成中都起着重要的作用,可促进晶状体上皮细胞的增殖并化生为纤维细胞,但其信号通路尚不清楚。目的：探讨ERK1/2信号转导通路在碱性成纤维细胞生长因子诱导的人晶状体上皮细胞环氧合酶2表达中的作用。方法：使用10μg/L的碱性成纤维细胞生长因子干预培养的人晶状体上皮细胞0,1,3,6,12,24h,RT-PCR检测刺激不同时间人晶状体上皮细胞环氧合酶2mRNA的表达,Western blot检测细胞中环氧合酶2及磷酸化ERK1/2的表达。在阻断实验中应用特异性ERK1/2的阻断剂PD98059阻断ERK信号转导通路1h,再用10μg/L碱性成纤维细胞生长因子刺激细胞6h,Western blot检测细胞中环氧合酶2的表达。结果与结论：碱性成纤维细胞生长因子刺激后的人晶状体上皮细胞中环氧合酶2mRNA及其蛋白的表达显著增加（P〈0.01）,同时碱性成纤维细胞生长因子诱导人晶状体上皮细胞磷酸化ERK1/2活性增强,表达水平随作用时间而增加,30min时达到最高峰（P〈0.01）,6h后恢复至基线水平;PD98059可抑制人晶状体上皮细胞环氧合酶2的表达（P〈0.01）。说明ERK1/2信号转导通路参与了碱性成纤维细胞生长因子诱导的人晶状体上皮细胞中环氧合酶2的表达,在后发性白内障的形成过程中起着重要作用。     

ERK1/2信号传导通路介导碱性成纤维细胞生长因子诱导人晶状体上皮细胞中环氧合酶2的表达

背景:碱性成纤维细胞生长因子在各种白内障形成中都起着重要的作用,可促进晶状体上皮细胞的增殖并化生为纤维细胞,但其信号通路尚不清楚。目的:探讨ERK1/2信号转导通路在碱性成纤维细胞生长因子诱导的人晶状体上皮细胞环氧合酶2表达中的作用。方法:使用10μg/L的碱性成纤维细胞生长因子干预培养的人晶状体上皮细胞0,1,3,6,12,24h,RT-PCR检测刺激不同时间人晶状体上皮细胞环氧合酶2mRNA的表达,Western blot检测细胞中环氧合酶2及磷酸化ERK1/2的表达。在阻断实验中应用特异性ERK1/2的阻断剂PD98059阻断ERK信号转导通路1h,再用10μg/L碱性成纤维细胞生长因子刺激细胞6h,Western blot检测细胞中环氧合酶2的表达。结果与结论:碱性成纤维细胞生长因子刺激后的人晶状体上皮细胞中环氧合酶2mRNA及其蛋白的表达显著增加(P<0.01),同时碱性成纤维细胞生长因子诱导人晶状体上皮细胞磷酸化ERK1/2活性增强,表达水平随作用时间而增加,30min时达到最高峰(P<0.01),6h后恢复至基线水平;PD98059可抑制人晶状体上皮细胞环氧合酶2的表达(P<0.01)。说明ERK1/2信号转导通路参与了碱性成纤维细胞生长因子诱导的人晶状体上皮细胞中环氧合酶2的表达,在后发性白内障的形成过程中起着重要作用。     

PD98059对高原红细胞增多症患者骨髓CD71~+、CD235a~+有核红细胞增殖和凋亡的影响

目的:研究Ras/Raf/MEK/ERK信号通路蛋白激酶MEK特异性抑制剂PD98059对高原红细胞增多症(HAPC)患者骨髓CD71~+、CD235a~+有核红细胞增殖和凋亡影响及HAPC发病机制。方法:采用免疫磁珠法分选16例HAPC患者及16例对照者骨髓CD71~+、CD235a~+有核红细胞,分别加入5、10和20μmol/L不同浓度PD98059及DM SO溶剂,低氧培养72 h,以Annexin V和PI双染流式细胞术测定细胞凋亡,CCK8检测细胞增殖。同时观察加入5、10和20μmol/L等不同浓度PD98059及DMSO溶剂对骨髓单个核细胞(BMMNC)红系集落形成能力。结果:HAPC患者骨髓CD71~+、CD235a~+有核红细胞凋亡率随PD98059浓度增加上升(r=0.807,P0.01);增殖率随PD98059浓度增加而下降(r=0.502,P0.01)。HAPC患者骨髓BM M NC红系集落形成率随PD98059浓度增加而下降(r=0.504,P0.01),7和14 d时各组比较均有统计学差异(P0.05)。结论:M EK特异性抑制剂PD98059对HAPC患者CD71~+、CD235a~+有核红细胞具有抑制增殖、促进凋亡作用,对红细胞过度积累有一定的抑制作用。     

丝裂原细胞外信号反应激酶阻断剂对缺氧诱导人视网膜色素上皮细胞增殖的影响

目的:观察特异性丝裂原细胞外信号反应激酶1(MEK1)阻断剂(PD98059)对缺氧刺激的人视网膜色素上皮细胞增殖的影响,并初步探讨其作用机制。方法:实验于2004-11/2005-11在江苏省人民医院中心实验室完成。①利用体积分数为0.95的N2和0.05的CO2混合气体建立培养的人视网膜色素上皮细胞细胞缺氧模型。②用3种不同浓度(10,50和100μmol/L)的P42/P44MAPK特异性阻断剂PD98059处理视网膜色素上皮细胞细胞。③在缺氧24h后用四甲基偶氮唑盐的方法检测细胞的增殖情况。④用反转录-聚合酶链反应的方法检测周期蛋白DmRNA的表达。⑤收集细胞进行流式细胞仪的检测,判断细胞的周期情况。结果:①缺氧刺激24h后视网膜色素上皮细胞增殖,缺氧组比正常组增加4.71%。②PD98059对视网膜色素上皮细胞细胞增殖有明显的抑制作用,并具有浓度依赖性;与缺氧组相比,缺氧 10mmol/L组、缺氧 50mmol/L组及缺氧 100mmol/L组抑制率分别是5.11%,11.66%和16.36%。③缺氧24h后,细胞周期蛋白DmRNA的浓度明显增加,不同浓度的PD98059对周期蛋白D的mRNA生成有明显的抑制作用,并且呈浓度依赖性,缺氧组与正常组比较周期蛋白D增加26.67%,与缺氧组比较,缺氧 10mmol/L组、缺氧 50mmol/L组及缺氧 100mmol/L组抑制率分别为18.93%,37.72%,57.58%。④缺氧时DNA合成前期细胞明显增多,细胞的增殖减少。结论:P42/P44MAPK信号转导通路可能通过对周期蛋白D的影响抑制缺氧时视网膜色素上皮细胞的增殖。     

PD98059下调GST-π表达增强人肠癌RKO细胞对奥沙利铂的敏感性

目的探讨在肠癌RKO细胞中,MAPK/ERK特异性抑制剂PD98059对奥沙利铂药物敏感性的影响及谷胱甘肽-S-转移酶π(GST-π)在这一过程中的作用。方法采用MTT法测定奥沙利铂和(或)PD98059处理后对人肠癌RKO细胞的增殖抑制影响;Western-blot方法检测PD98059作用人肠癌RKO细胞24 h后,RKO细胞中p-ERK及GST-π蛋白的表达。结果奥沙利铂作用人肠癌RKO细胞24、48和72 h,IC50值分别为38.72、23.41、10.81μg/ml,20μmol/L PD98059预处理RKO细胞24 h后,再加入奥沙利铂培养24、48和72 h,联合用药组细胞增殖率明显低于对照组,RKO细胞对奥沙利铂的药物敏感性显著增强。20μmol/L PD98059作用RKO细胞24 h后,p-ERK蛋白表达明显下调,GST-π蛋白表达亦明显下调。结论 PD98059通过有效抑制ERK通路,进一步下调人肠癌RKO细胞内GST-π的表达,增强RKO对奥沙利铂的药物敏感性。     

肿瘤抑素影响血管瘤内皮细胞凋亡的相关机制分析

目的研究肿瘤抑素对血管瘤内皮细胞的增殖与凋亡过程的调节作用,为临床婴幼儿血管瘤的治疗提供参考。方法血管瘤内皮细胞培养后随机分为5组:对照组、PD98059组、肿瘤抑制素低剂量、中剂量和高剂量组。除对照组给予生理盐水外,其余各组给予PD98059(10μM)处理2 h,肿瘤抑制素低剂量、中剂量和高剂量组分别给予1μM、10μM、100μM的肿瘤抑制素处理2 h。免疫印迹法或荧光定量法分析各组细胞凋亡相关蛋白Caspase3/9、ERK信号通路关键蛋白ERK1/2和MEK及氧化应激蛋白NOX4的表达,DHE染色法分析各组细胞的氧化应激状态。结果与对照组相比,PD98059组血管瘤内皮细胞内ROS水平明显降低、细胞凋亡蛋白Caspase3/9的表达明显升高;同时ERK信号通路关键蛋白的表达明显增强,而肿瘤抑制素低剂量、中剂量和高剂量组作用与PD98059作用一致,且具有剂量依从性。结论肿瘤抑制素通过激活氧化应激状态、ERK信号及抑制细胞凋亡蛋白通过发挥对血管瘤内皮细胞增殖的抑制作用。     

姜黄素对脂多糖诱导人支气管上皮细胞 丝裂素活化蛋白激酶信号通路的影响

目的 探讨姜黄素对脂多糖(LPS)诱导人支气管上皮细胞三磷酸肌醇激酶(PI3K)、蛋白激酶B (Akt)、外调节蛋白激酶(ERK)、核转录因子-κB(NF-κB)、不规则趋化因子(CX3CL1)表达的影响.方法 体外培养人支气管上皮细胞24 h后,用计算机生成的随机分配法表分为空白组(CK)、LPS(10 mg/L)组、PD组 (LPS+ ERK抑制剂PD98059,25μmol/L)、LY组(LPS+ PI3K/Akt抑制剂LY294002,20μmol/L)、PDTC组 (LPS+ NF-κB抑制剂PDTC,100μmol/L)、cur组(LPS+姜黄素,10μmol/L)6组.各组阻断剂预处理30 min后给予LPS刺激,加药后作用4 h,用蛋白质免疫印迹试验(Western Blot)检测各组PI3K、Akt、ERK、NF-κB、CX3CL1表达,测定各条带吸光度(A)值.结果 与CK组比较,LPS组PI3K、Akt、ERK、NF-κB、CX3CL1表达均显著升高〔PI3K(A值):0.68±0.05比0.49±0.09,Akt(A值):0.54±0.03比0.30±0.06,ERK(A值):1.09±0.09比0.74±0.05、NF-κB(A值):1.87±0.15比0.57±0.30,CX3CL1(A值):0.62±0.12比0.34±0.00,均P<0.05〕.与LPS组比较,PD组、PDTC组PI3K、Akt、ERK、NF-κB、CX3CL1表达均明显下降〔PI3K(A值):0.37±0.06、0.38±0.16比0.68±0.05,Akt(A值):0.33±0.07、0.33±0.12比0.54±0.03,ERK(A值):0.67±0.05、0.82±0.26比1.09±0.09,NF-κB(A值):0.73±0.19、0.97±0.41比1.87±0.15,CX3CL1(A值):0.43±0.07、0.32±0.03比0.62±0.12,均P<0.05〕;cur组能明显抑制PI3K、Akt、ERK、NF-κB表达〔PI3K(A值):0.44±0.04比0.68±0.05, Akt(A 值):0.30±0.10 比 0.54±0.03,ERK(A 值):0.78±0.05 比 1.09±0.09,NF-κB(A 值):0.78±0.17 比1.87±0.15,均P<0.05〕.结论 人支气管上皮细胞存在LPS—ERK、NF-κB—CX3CL1信号通路,姜黄素可抑制LPS诱导人支气管上皮细胞后PI3K/Akt、ERK、NF-κB的表达.     

Anesthesia (4)

Bruno Guignard, Anne Elisabeth Bossard, Carole Coste, et al:Intraoperative remifentanil increases postoperative pain and morphine requirement. (Hôpital Ambroise Paré, Boulogne-Billancourt, France) Anesthesiology 2000;93:409– 417.
The study tested the hypothesis that intraoperative remifentanil administration results in acute opioid tolerance that is manifested by increased postoperative pain and opioid requirement. Fifty adult patients undergoing major abdominal surgery were randomly assigned to 2 anesthetic regimens: (1) the remifentanil group or (2) the desflurane group. All patients were given a bolus of 0.15 mg/kg morphine 40 min before the end of surgery. Morphine was initially titrated to need by postanesthesia care nurses blinded to group assignment. Subsequently, patients—who were blinded to group assignment—controlled their own morphine administration. Pain scores and morphine consumption were recorded for 24 postoperative h. The results indicated that the mean remifentanil infusion rate was 0.3 ± 0.2 μg · kg⁻¹· min⁻¹ in the remifentanil group, which was significantly greater than in the desflurane group. Intraoperative hemodynamic responses were similar in each group. Postoperative pain scores were significantly greater in the remifentanil group. These patients required morphine significantly earlier than those in the desflurane group and needed nearly twice as much morphine in the first 24 postoperative h: 59 mg (25% to 75% interquartile range, 43–71) versus 32 mg (25% to 75% interquartile range, 19–59; P <0.01). Conclude that relatively large-dose intraoperative remifentanil increased postoperative pain and morphine consumption. These data suggest that remifentanil causes acute opioid tolerance and hyperalgesia.     

Alpha(4)beta(7)/alpha(4)beta(1) dual integrin antagonists block alpha(4)beta(7)-dependent adhesion under shear flow

The alpha(4) integrin, alpha(4)beta(7), plays an important role in recruiting circulating lymphocytes to the gastrointestinal tract, where its ligand mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is preferentially expressed on high endothelial venules (HEVs). Dual antagonists of alpha(4)beta(1) and alpha(4)beta(7), N-(2,6-dichlorobenzoyl)-(L)-4-(2',6'-bis-methoxyphenyl)phenylalanine (TR14035) and N-(N-[(3,5-dichlorobenzene)sulfonyl]-2-(R)-methylpropyl)-(D)-phenylalanine (compound 1), were tested for their ability to block the binding of alpha(4)beta(7)-expressing cells to soluble ligand in suspension and under in vitro and in vivo shear flow. Compound 1 and TR14035 blocked the binding of human alpha(4)beta(7) to an (125)I-MAdCAM-Ig fusion protein with IC(50) values of 2.93 and 0.75 nM, respectively. Both compounds inhibited binding of soluble ligands to alpha(4)beta(1) or alpha(4)beta(7) on cells of human or rodent origin with similar potency. Under shear flow in vitro, TR14035 and compound 1 blocked binding of human alpha(4)beta(7)-expressing RPMI-8866 cells or murine mesenteric lymph node lymphocytes to MAdCAM-Ig with IC(50) values of 0.1 and 1 microM, respectively. Intravital microscopy was used to quantitate alpha(4)-dependent adhesion of fluorescent murine lymphocytes in Peyer's patch HEVs. When cells were prestimulated with 2 mM Mn(2+) to activate alpha(4)beta(7) binding to ligand, anti-alpha(4) monoclonal antibody (mAb) [10 mg/kg (mpk) i.v.] blocked adhesion by 95%, and anti-beta(1) mAb did not block adhesion, demonstrating that this interaction was dependent on alpha(4)beta(7). TR14035 blocked adhesion to HEVs [ED(50) of 0.01-0.1 mpk i.v.], and compound 1 blocked adhesion by 47% at 10 mpk i.v. Thus, alpha(4)beta(7)/alpha(4)beta(1) antagonists blocked alpha(4)beta(7)-dependent adhesion of lymphocytes to HEVs under both in vitro and in vivo shear flow.     

CTLA4-Ig (abatacept)

Although tumor necrosis factor (TNF) antagonists have dramatically improved the outcome of patients with rheumatoid arthritis (RA), some of the patients do not respond or cannot tolerate these drugs. Abatacept is a recombinant fusion protein containing components of IgG and cytotoxic T-lymphocyte-associated antigen-4 that inhibit costimulatory signal from antigen presenting cells and prevent activation of T cells. Several clinical trials have demonstrated the excellent efficacy and safety of abatacept in patients with RA who are resistant to methotrexate or TNF antagonists. Abatacept improved clinical signs and symptoms and quality of life of patients with RA and also retarded their radiological progression of structural damage of affected joints. The safety concerns, especially for infections and malignancies, are raised and should be strictly monitored in clinical trials and future clinical practice in Japan as well as in Western countries.