Caspase 3与肺炎链球菌引起的肺泡上皮细胞凋亡的关系

目的:通过肺炎链球菌体外感染肺泡上皮细胞探讨凋亡蛋白caspase 3的活性和肺泡上皮细胞凋亡率的变化及凋亡蛋白caspase 3对肺泡上皮细胞凋亡的作用.方法:体外培养肺泡上皮细胞A549,用肺炎链球菌R6体外感染A549,TUNEL法检测A549细胞凋亡,RT-PCT法检测caspase 3基因转录强度,化学荧光测定法检测caspase 3.结果:肺炎链球菌能时间依赖性地诱导A549凋亡;Caspase 3的基因翻译强度与蛋白活性随感染时间延长呈上升趋势,而且与A549细胞凋亡变化同步.结论:Caspase 3在肺炎链球菌诱导的肺泡上皮细胞凋亡过程中起重要作用.     

miR-23b-3p靶向PALM3对肺炎链球菌诱导的肺泡上皮细胞凋亡及炎症因子表达的影响

目的研究miR-23b-3p对肺炎链球菌诱导的肺泡上皮细胞凋亡和炎症的作用及机制。方法将肺泡上皮细胞A549细胞分为对照组、感染组、转染组、感染组+转染组;对照组A549细胞常规培养,感染组用1×108 CFU/mL肺炎链球菌培养A549细胞,转染组转染不同载体,感染组+转染组在A549细胞被肺炎链球菌处理前48h进行转染。qRT-PCR检测细胞中miR-23b-3p和paralemmin-3(PALM3)mRNA的水平,流式细胞术检测细胞凋亡率,Western blot检测细胞中PALM3、B淋巴细胞瘤-2基因(Bcl-2)和Bcl-2相关X蛋白(Bax),酶联免疫法(ELISA)检测肺炎链球菌诱导后细胞培养上清中白介素-6(interleukin 6,IL-6)和白介素-10(interleukin 10,IL-10)的含量;双荧光素酶报告系统验证miR-23b-3p与PALM3的关系。结果与对照组相比,感染组A549细胞中miR-23b-3p、IL-10、Bcl-2含量明显降低(P0.05),PALM3、IL-6、Bax水平及细胞凋亡率明显升高(P0.05);过表达miR-23b-3p和干扰PALM3表达均可抑制肺炎链球菌诱导的A549细胞凋亡和炎症;miR-23b-3p靶向负调控PALM3的表达;过表达PALM3逆转了过表达miR-23b-3p对肺炎链球菌诱导的A549细胞凋亡和炎症的作用。结论 miR-23b-3p靶向PALM3抑制肺炎链球菌诱导的A549炎症和细胞凋亡。     

沉默Par-4基因表达可抑制肺泡上皮细胞凋亡

目的 研究促凋亡基因Par-4沉默对氧化应激导致的肺泡上皮细胞凋亡的影响.方法 培养人肺泡Ⅱ型上皮细胞A549细胞.利用过氧化氢诱导细胞凋亡.利用小RNA干扰(siRNA)技术,靶向诱导Par-4基因沉默.设立正常对照组(常规培养细胞)、过氧化氢组(1.0 mmol/L过氧化氢处理细胞)、过氧化氢+Par-4-siRNA组(1.0 mmol/L过氧化氢和Par-4-siRNA转染的细胞).设非抑制序列转染的对照组.流式细胞术测定各组细胞凋亡百分率.Western blot检测促凋亡基因Smac蛋白表达量.凝胶迁移率改变试验测定转录因子E2F1的DNA结合力.比色法检测Caspase-3酶活性.实验结果采用单因素方差分析(F检验和g检验).结果 过氧化氢+Par-4-siRNA组细胞凋亡百分率(29.7±2.3)%显著低于过氧化氢组(54.2±4.1)%,q=8.91,P＜0.01.Par-4-siRNA的转染显著抑制过氧化氢诱导的肺泡上皮细胞中Smac蛋白表达、E2F1DNA结合力和caspase-3活性上调.结论 采用siRNA诱导Par-4基因沉默,可减少氧化应激导致的肺泡上皮细胞凋亡.其分子机制可能和抑制Smac蛋白表达、抑制E2F1 DNA结合力和抑制caspase-3活性有关.

Abstract：

Objective To investigate the effects of Par-4 gene silence on hydrogen peroxide-induced apoptosis in alveolar epithelial cells. Method The alveolar epithelial cells A549 were cultured and exposed to hydrogen peroxide. The siRNA sequences targeted Par-4 gene was chemically synthesized and transfected to A549 cells with or without the exposure of hydrogen peroxide. The cells were divided into normal control groups, hydrogen peroxide-treated group(The cells were treated with 0. 1 mmol/L hydrogen peroxide), hydrogen peroxide and Par-4-siRNA-treated group(The cells were treated with 0. 1 mmol/L hydrogen peroxide after transfection of Par-4-siRNA), Non-specific DNA sequence transfection control group. The apoptosis of A549 cells was quantified by flow cytometry. The expression of Smac protein was detected by Western blot.Electrophoretic mobility shift assay was applied for evaluating the change of E2F1 DNA binding activity. Relative activity of Caspase-3 was detected by clolorimetric assay. Results The percent of apoptotic cells in hydrogen peroxide and Par-4-siRNA-treated group was (29.7 ± 2.3) %, which was significantly lower than that of hydrogen peroxide-treated group [(54.2 ± 4.1)%, q= 8.91, P ＜ 0.01)]. Par-4 siRNA could significantly suppress the increase of Smac protein, E2F1 DNA binding activity and caspase-3 activity induced by hydrogen peroxide in A549 cells. Conclusions Par-4 gene silence induced by siRNA might inhibit the apoptosis of alveolar epithelial cells, which might be resulted from suppression of the up-regulation of Smac gene expression, E2F1 DNA binding activity and caspase-3 activity.     

肺炎链球菌通过Wnt信号通路介导肺腺癌细胞A549损伤的机制研究

目的研究肺炎链球菌刺激对肺腺癌细胞A549损伤的影响及作用机制。方法体外培养肺泡Ⅱ型上皮细胞A549,分为对照组和肺炎链球菌R6刺激组。R6刺激组将肺炎链球菌按照1×10~8个/ml的量加入A549细胞中进行刺激,对照组加入等体积的曲古抑素A(TSA)处理作为对照。分别处理8 h、16 h、24 h、32 h,MTT检测处理各时间点A549细胞存活情况;流式细胞仪检测R6刺激24 h后A549细胞凋亡情况;酶联免疫吸附法(ELISA)检测R6刺激24 h后炎症因子白介素6(IL-6)、IL-10含量变化;Western-blot检测R6刺激24 h后A549细胞凋亡相关蛋白及Wnt通路蛋白表达。结果 R6刺激显著抑制A549细胞存活,与对照组相比,差异具有显著性(P0.05),R6刺激24 h对A549细胞存活抑制效果最明显。R6刺激24 h后,A549细胞凋亡率增高,与对照组相比,差异具有显著性(P0.05)。R6刺激24 h后促炎因子IL-6含量显著增加,抗炎因子IL-10含量明显降低,与对照组相比,差异具有显著性(P0.05)。Western-blot结果显示R6刺激后,促凋亡因子Bax、Cleaved-caspase3蛋白表达显著升高,抑凋亡因子Bcl-2表达明显下降,与对照组相比,差异具有显著性(P0.05),Wnt通路蛋白β-catenin、p-GSK-3β表达明显升高,p-β-catenin、GSK-3β表达明显下降,与对照组相比,差异具有显著性(P0.05)。结论肺炎链球菌刺激会对肺腺癌细胞A549损伤造成损伤,这一过程与Wnt信号通路的激活有关。     

碱性成纤维细胞生长因子荧光真核表达载体构建及对过氧化氢诱导血管内皮细胞凋亡的影响

背景:已证实外源性碱性成纤维细胞生长因子(basic fibroblast growth factor,bFGF)可抑制血管内皮细胞凋亡。目的:构建表达bFGF的荧光真核表达载体,探讨其对过氧化氢(H2O2)诱导的血管内皮细胞凋亡和凋亡相关蛋白的影响。方法:通过基因亚克隆构建荧光真核表达载体pcDNA3.1-bFGF-GFP,利用脂质体介导将bFGF基因导入人脐静脉内皮细胞内,通过荧光观察和RT-PCR检测基因的表达。实验分为3组,对照组(转染pcDNA3.1)、过氧化氢组(转染pcDNA3.1+H2O2)和bFGF转染+过氧化氢组(转染pcDNA3.1-bFGF-GFP+H2O2),流式细胞术测定细胞凋亡率,Western blot检测caspase-3 P17活性亚单位和Bax蛋白表达。结果与结论:成功构建荧光真核表达载体pcDNA3.1-bFGF-GFP,该载体转染人脐静脉内皮细胞后,bFGF mRNA显著增加,并可观察到绿色荧光。与对照组相比,过氧化氢组细胞凋亡率和caspase-3 P17活性亚单位、Bax蛋白的表达量都明显增加(P<0.01),而bFGF转染+过氧化氢组的细胞凋亡率和caspase-3 P17活性亚单位、Bax蛋白的表达量则比过氧化氢组显著降低(P<0.01)。证实bFGF基因转染能抑制过氧化氢诱导的血管内皮细胞凋亡,其作用机制可能与调控Bax蛋白表达和caspase-3活性有关。     

环氧化酶-2RNA干扰对肺癌A549细胞凋亡及caspase家族的影响

目的观察环氧化酶-2（COX-2）RNA干扰对肺癌细胞凋亡的影响,以及对凋亡调控蛋白caspase-8、caspase-9、caspase-3的调控作用。方法构建COX-2特异性干扰质粒,并转染至肺癌A549细胞株中,AnnexinV-FITC／PI联合流式细胞仪检测细胞凋亡,Western Blot检测caspase-8、caspase-9、caspase-3的活性。结果成功构建COX-2特异性干扰质粒并转染至肺癌A549细胞株中,获得抑制COX-2表达的肺癌细胞模型;干扰COX-2的A549细胞凋亡率[（24．3±2．46）％]较未干扰组[（6．52±0．13）％]明显升高（P〈0．01）。干扰COX-2的肺癌细胞．4549caspase．8蛋白表达（0．86±0．09）较未干扰组（0．12±0．01）明显升高（P〈0．01）,caspase-3蛋白表达（0．94±0．09）较未干扰组（0．16±0．02）明显升高（P〈0．01）,caspase-9蛋白表达（1．12±0．11）较未干扰组（0．13±0．01）明显升高（P〈0．01）。结论干扰COX-2可以促进肺癌A549细胞的凋亡,并且活化caspase-8及caspase-9,从而活化caspase-3。     

碱性成纤维细胞生长因子荧光真核表达载体构建及对过氧化氢诱导血管内皮细胞凋亡的影响

背景：已证实外源性碱性成纤维细胞生长因子（basic fibroblast growth factor,bFGF）可抑制血管内皮细胞凋亡。目的：构建表达bFGF的荧光真核表达载体,探讨其对过氧化氢（H2O2）诱导的血管内皮细胞凋亡和凋亡相关蛋白的影响。方法：通过基因亚克隆构建荧光真核表达载体pcDNA3.1-bFGF-GFP,利用脂质体介导将bFGF基因导入人脐静脉内皮细胞内,通过荧光观察和RT-PCR检测基因的表达。实验分为3组,对照组（转染pcDNA3.1）、过氧化氢组（转染pcDNA3.1＋H2O2）和bFGF转染＋过氧化氢组（转染pcDNA3.1-bFGF-GFP＋H2O2）,流式细胞术测定细胞凋亡率,Western blot检测caspase-3 P17活性亚单位和Bax蛋白表达。结果与结论：成功构建荧光真核表达载体pcDNA3.1-bFGF-GFP,该载体转染人脐静脉内皮细胞后,bFGF mRNA显著增加,并可观察到绿色荧光。与对照组相比,过氧化氢组细胞凋亡率和caspase-3 P17活性亚单位、Bax蛋白的表达量都明显增加（P〈0.01）,而bFGF转染＋过氧化氢组的细胞凋亡率和caspase-3 P17活性亚单位、Bax蛋白的表达量则比过氧化氢组显著降低（P〈0.01）。证实bFGF基因转染能抑制过氧化氢诱导的血管内皮细胞凋亡,其作用机制可能与调控Bax蛋白表达和caspase-3活性有关。     

大黄素对肺炎链球菌感染的肺泡上皮细胞损伤的作用及其机制研究

【目的】探讨大黄素对肺炎链球菌感染的肺泡上皮细胞损伤的作用及其机制研究。【方法】肺泡上皮细胞A549随机分为对照组、模型组、20μg/mL组、40μg/mL组、80μg/mL组、160μg/mL组,对照组细胞常规培养,其余组细胞均经过肺炎链球菌感染,20μg/mL组、40μg/mL组、80μg/mL组、160μg/mL组细胞在感染后24 h分别加入不同浓度的大黄素(20μg/mL、40μg/mL、80μg/mL、160μg/mL)处理。噻唑蓝(MTT)检测各组A549细胞的增殖;流式细胞术检测凋亡率;酶联免疫吸附测定法(ELISA)检测白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)水平;蛋白质印迹法检测A549细胞中B细胞淋巴瘤/白血病-2(Bcl-2)、Bcl-2相关X蛋白(Bax)、活化的含半胱氨酸的天冬氨酸蛋白水解酶3(Cleaved Caspase-3)、β-连环蛋白(β-catenin)、细胞周期蛋白D1(Cyclin D1)蛋白水平。【结果】与对照组相比,肺炎链球菌感染的A549细胞增殖活性、Bcl-2、β-catenin、Cyclin D1蛋白水平降低(P<0.05),凋亡率及IL-6、TNF-α、Bax和Cleaved Caspase-3蛋白水平增加(P<0.05);不同浓度大黄素促进肺炎链球菌感染的A549细胞增殖(P<0.05),抑制其凋亡(P<0.05),降低IL-6、TNF-α水平(P<0.05),增加Bcl-2蛋白水平(P<0.05),下调Bax和Cleaved Caspase-3蛋白水平(P<0.05),提高β-catenin、Cyclin D1蛋白水平(P<0.05)。【结论】大黄素可能通过调节Wnt/β-catenin信号通路从而促进肺炎链球菌感染的肺泡上皮细胞增殖,抑制其凋亡。     

海水干预下人肺泡上皮细胞低氧诱导因子1α与TNF-α、IL-6表达的变化

目的:探讨海水干预对人肺泡上皮细胞低氧诱导因子1α蛋白及TNF-α、IL-6表达的影响.方法:肺泡上皮细胞来源的A549细胞系,分为正常对照组(C)和海水处理组(S).C组用新鲜培养基常规培养,S组经灭菌配方海水孵育0.5、1、2、4、8、16h,蛋白免疫印记法(western blot)检测各组细胞HIF-1α蛋白的表达,放射免疫法检测细胞培养上清液中TNF-α、IL-6的含量.结果:(1)HIF-1α在海水干预1h后开始升高,4h达高峰(P＜0.01),此后下降,但仍显著高于对照组(P＜0.01).(2)TNF-α与IL-6在海水干预1h后开始升高,2h达高峰(P＜0.01),4h及8h组较对照组无统计学差异.结论:海水干预可诱导肺泡上皮细胞HIF-1α蛋白及炎性因子TNF-α、IL-6的表达;HIF-1α在海水干预致肺泡上皮细胞炎症反应过程中可能起重要作用.     

大黄素对K562细胞抑制增殖和诱导凋亡的作用

本研究观察中药大黄素（emodin）对人慢性髓系白血病K562细胞株的增殖及凋亡影响,探讨P210融合蛋白和caspase-3激活在其中的作用。采用MTT法、集落形成试验观察大黄素对K562增殖的影响;AnnexinV FITC／PI法、DNA倍体分析及DNA凝胶电泳法检测细胞凋亡;Westem blot检测大黄素作用后不同时间段P210、磷酸化P210、caspase。3前体蛋白及PARP表达水平的变化。结果表明,大黄素能抑制K562细胞增殖,作用48小时的半数抑制浓度（IC50）为38．25μmol/L;Annexin V FITC／PI法、亚二倍体峰（凋亡峰）及DNA片段化检测证实,大黄素能诱导K562细胞凋亡,并呈量效关系。大黄素作用飚62细胞后P210、磷酸化P210、caspase-3前体蛋白表达水平均有不同程度下调,PARP的活性片段85kD表达增加,这些变化呈时效关系。结论：大黄素能够有效抑制K562细胞增殖并诱导其凋亡。P210磷酸化抑制,P210表达下调和caspase-3激活可能参与了该过程。     

Hypocapnic alkalosis enhances oxidant-induced apoptosis of human alveolar epithelial type II cells

Apoptosis of alveolar epithelial type II (AEC-II) cells induced by reactive oxygen species (ROS) contributes to extensive alveolar damage during acute lung injury. Hypercapnic acidosis and hypocapnic alkalosis are known to modulate ROS-mediated lung damage. This study assessed the effects of acid-base balance disturbances on hydrogen peroxide (H2O2)-induced apoptosis of the AEC-II-like human cell line A549, which was cultured under different conditions of pH and CO2 tension (normal pH and CO2, hypercapnic acidosis, metabolic acidosis, hypocapnic alkalosis and metabolic alkalosis). H2O2-induced apoptosis was assessed by a dye-uptake bioassay and induction of caspase activity, which were quantified using analytical digital photomicroscopy. Acidosis or alkalosis of the culture medium alone did not induce A549 cell apoptosis. Hypocapnic alkalosis significantly increased H2O2-induced apoptosis and caspase activation of A549 cells. Metabolic alkalosis non-significantly increased H2O2-induced A549 cell apoptosis and caspase activation. These data suggest that hypocapnic alkalosis intensifies oxidative-induced apoptosis of alveolar epithelial cells.     

大鼠创伤性脑损伤后神经细胞凋亡的动态变化及其与caspase-3基因表达的关系

目的 探讨创伤性脑损伤(TBI)后神经细胞凋亡的变化规律及其与caspase-3基因表达的关系.方法 成年健康封闭群SD大鼠120只,随机分为对照组8只、损伤组和抑制物组各56只.Feeney法致伤,抑制物组伤后脑内注射5μg caspase-3抑制剂z-DEVD-fmk.分别在伤后1,6,24,48 h和3,7,14 d处死取材(每个分析时相点8只大鼠),采集伤灶中心皮质、皮层下白质、海马、齿状回,以及对侧相应部位脑组织,应用原位末端脱氧核糖核酸转移酶介导的脱氧尿苷三磷酸(dUTP)标记法(TUNEL法)和流式细胞术检测神经细胞凋亡的变化;免疫组化法、蛋白印迹(western blot)和半定量逆转录-聚合酶链式反应(RT-PCR),检测caspase-3蛋白和mRNA的表达;并借助荧光分析试剂盒检测caspase-3活性的变化.所得数据采用SIDSS 10.1统计软件包进行Sprarman等级相关分析和方差分析(sNK-α检验).结果 伤后伤侧各脑区神经细胞凋亡指数(AI)和细胞凋亡百分率(AP)迅速增高,24～48 h达峰值,随后逐渐下降,但伤后14 d仍高于正常(P＜0.01).伤后caspase-3蛋白和mRNA的表达明显增加,caspase-3活性迅速上升,峰值在24～48 h.其中伤后24 h伤侧海马区caspase-3蛋白谱密度与对照组相比增加1484%,caspase-3 mRNA的表达量增加1043%,caspase-3活性增加148%;伤后48h伤灶皮层下白质caspase-3蛋白谱密度增加1690%,caspase-3 mRNA的表达量增加1181%,caspase-3活性增加183%.Western blot显示,伤后caspase-3原酶及p17活性亚单位的表达均增强.抑制物组caspase-3蛋白和mRNA的表达均明显下降,caspase-3活性明显降低;同时,AI值和AP值也明显降低.统计学相关分析发现.伤后神经细胞凋亡与caspase-3 mRNA和蛋白的表达间呈正相关(r=0.821和r:0.638,P＜0.01),伤后caspase-3在mRNA和蛋白水平的表达间呈正相关(r=0.945,P＜0.01).结论 急性TBI后神经细胞凋亡的发生与caspase-3的激活有关;神经细胞凋亡与其调节基因caspase-3的表达间具有一致性,TBI对caspase-3的调节发生在转录水平前的某一环节.caspase-3抑制剂能有效地阻断TBI后的神经细胞凋亡.     

Interleukin-8 gene expression by a pulmonary epithelial cell line. A model for cytokine networks in the lung.

Cellular constituents of the alveolar-capillary wall may be key participants in the recruitment of polymorphonuclear leukocytes to the lung through the generation of the novel neutrophil chemotactic peptide interleukin-8 (IL-8). This interaction appears to occur via the ability of human alveolar macrophage (AM)-derived monokines, tumor necrosis factor (TNF), and interleukin-1 (IL-1) to induce gene expression of IL-8 from pulmonary type II-like epithelial cells (A549). Northern blot analysis demonstrated that steady-state IL-8 mRNA expression, by either TNF- or IL-1 beta-treated A549 cells, occurred in both a dose- and time-dependent fashion. Similarly, extracellular antigenic IL-8, as assessed by specific ELISA, was expressed from TNF- or IL-1 beta-stimulated epithelial cells in a time-dependent fashion with maximal IL-8 antigen detected at 24 h poststimulation. Immunohistochemical staining utilizing rabbit anti-human IL-8 antibody identified immunoreactive, cell-associated IL-8 antigen as early as 8 h post-TNF or IL-1 beta stimulation. A549-generated neutrophil chemotactic bioactivity paralleled IL-8 steady-state mRNA levels. Signal specificity was demonstrated in this system as IL-8 mRNA or protein expression by lipopolysaccharide (LPS)-treated A549 cells was not different from unstimulated cells. Although LPS did not serve as a direct stimulus for the production of IL-8 by type II-like epithelial cells, the condition media from LPS-challenged AM induced a significant expression of IL-8 mRNA by the A549 cells. 24-h conditioned media from LPS-treated cells was as potent as either IL-1 beta or TNF in generating steady-state IL-8 mRNA by A549 cells. Preincubation of LPS-treated AM-conditioned media with anti-human TNF or IL-1 beta neutralizing antibodies resulted in significant abrogation of IL-8 gene expression by A549 pulmonary epithelial cells. These findings demonstrate potential cell-to-cell communication circuits that may be important between AMs and pulmonary epithelial cells during the recruitment phase of acute lung inflammation.     

Boswellic acid acetate induces apoptosis through caspase-mediated pathways in myeloid leukemia cells

The mechanism of the cytotoxic effect of boswellic acid acetate, a 1:1 mixture of alpha-boswellic acid acetate and beta-boswellic acid acetate, isolated from Boswellia carterri Birdw on myeloid leukemia cells was investigated in six human myeloid leukemia cell lines (NB4, SKNO-1, K562, U937, ML-1, and HL-60 cells). Morphologic and DNA fragmentation assays indicated that the cytotoxic effect of boswellic acid acetate was mediated by induction of apoptosis. More than 50% of the cells underwent apoptosis after treatment with 20 mug/mL boswellic acid for 24 hours. This apoptotic process was p53 independent. The levels of apoptosis-related proteins Bcl-2, Bax, and Bcl-XL were not modulated by boswellic acid acetate. Boswellic acid acetate induced Bid cleavage and decreased mitochondrial membrane potential without production of hydrogen peroxide. A general caspase inhibitor (Z-VAD-FMK) and a specific caspase-8 inhibitor II (Z-IETD-FMK) blocked boswellic acid acetate-induced apoptosis. The mRNAs of death receptors 4 and 5 (DR4 and DR5) were induced in leukemia cells undergoing apoptosis after boswellic acid acetate treatment. These data taken together suggest that boswellic acid acetate induces myeloid leukemia cell apoptosis through activation of caspase-8 by induced expression of DR4 and DR5, and that the activated caspase-8 either directly activates caspase-3 by cleavage or indirectly by cleaving Bid, which in turn decreases mitochondria membrane potential.     

MiR-146b在白藜芦醇保护缺氧/复氧心肌细胞损伤中的作用及其机制

目的:探讨miR-146b在白藜芦醇保护缺氧/复氧(hypoxia/reoxygenation,H/R)心肌细胞损伤中的作用及其机制。方法:将体外培养的心肌细胞分为正常组、H/R组、白藜芦醇组、白藜芦醇+antimiR-NC组和白藜芦醇+anti-miR-146b组。采用荧光定量PCR检测miR-146b的表达,ELISA法检测细胞上清液中IL-1β,TNF-α和IL-6含量,MTT法检测细胞存活率,比色法检测LDH漏出率,流式细胞仪检测细胞凋亡率,蛋白质印迹法检测Bcl-2,caspase-3,NF-κB和TRAF6蛋白的表达,双荧光素酶报告基因实验检测miR-146b和TRAF6的靶向关系。结果:与正常组相比,H/R组细胞中miR-146b和Bcl-2蛋白的表达水平、细胞存活率显著降低,而细胞上清液中IL-1β,TNF-α,IL-6含量和LDH漏出率、细胞凋亡率以及caspase-3,NF-κB蛋白的表达水平显著升高(P<0.05);与H/R组相比,白藜芦醇组中miR-146b和Bcl-2蛋白的表达水平、细胞存活率显著升高,而IL-1β,TNF-α,IL-6含量和LDH漏出率、细胞凋亡率以及caspase-3,NF-κB蛋白的表达水平显著降低(P<0.05);与白藜芦醇组相比,白藜芦醇+anti-miR-146b组中miR-146b和Bcl-2蛋白的表达水平、细胞存活率显著降低,而IL-1β,TNF-α,IL-6含量和LDH漏出率,细胞凋亡率以及caspase-3,NF-κB蛋白的表达水平显著升高(P<0.05);而白藜芦醇+anti-miR-NC组与白藜芦醇组相比差异无统计学意义(P>0.05)。双荧光素酶报告基因和蛋白质印迹法证实TRAF6是miR-146b靶基因,且miR-146b可靶向调控其表达。结论:miR-146b抑制心肌细胞凋亡和炎症反应是白藜芦醇减轻H/R心肌细胞损伤的调控机制,其作用原理可能与靶向调控TRAF6有关。     

雄黄对急性白血病细胞株存活蛋白(survivin) 基因表达的影响及其意义

为了研究雄黄对白血病细胞抗凋亡基因存活蛋白(survivin)表达的影响，以白血病细胞系HL-60和Jurkat为模型．同时应用Western blot法和免疫荧光法检测survivin的表达；应用免疫组织化学SABC法检测白血病细胞系凋亡前后Fas、caspase-3的表达。结果表明：雄黄作用前两种细胞系survivin表达均呈阳性；Jurkat细胞Fas阳性，但无caspase-3表达；HL-60细胞株均无。Fas和caspase-3的表达。经雄黄作用后，两株细胞系survivin表达水平均降低．以HL-60细胞株降低显著，呈时间-浓度依赖关系。雄黄作用后HL-60细胞caspase-3表达转为阳性，Jurkat细胞caspase-3表达仍为阴性；Fas表达在Jurkat细胞稍减低，HL-60细胞仍为阴性。结论：雄黄可降低白血病细胞survivin的表达；survivin表达下调在雄黄通过线粒体途径促进细胞凋亡中发挥重要作用。     

地黄低聚糖对过氧化氢-血清饥饿诱导的脂肪组织来源干细胞凋亡的影响

目的探讨地黄低聚糖(RGOs)对过氧化氢-血清饥饿诱导的脂肪组织来源干细胞(ASCs)凋亡的影响。方法过氧化氢(200μM)联合血清饥饿(H2O2/SD,6 h)建立小型猪ASCs凋亡模型。RGOs(0.01 g/L、0.1 g/L、1 g/L、10 g/L)预处理12h并继续干预6 h。Annexin V-FITC/PI检测细胞凋亡率,CCK-8法测定细胞活性,酶标仪比色法测定细胞caspase-3的活性。结果 RGOs在一定浓度范围(0.1~10 g/L)可以减轻H2O2/SD引起的ASCs损伤,表现在细胞凋亡率下降,细胞活性增加,caspase-3活性降低。结论地黄低聚糖对过氧化氢-血清饥饿诱导的脂肪组织来源干细胞的凋亡具有保护作用。     

Perfluorocarbon blocks tumor necrosis factor-alpha-induced interleukin-8 release from alveolar epithelial cells in vitro

OBJECTIVE: To determine whether tumor necrosis factor (TNF)-alpha-induced interleukin (IL)-8 production by pulmonary alveolar epithelial cells is blocked by perfluorocarbon (PFC). DESIGN: Controlled, laboratory investigation of IL-8 production by pulmonary alveolar epithelial cells after exposure to PFC in vitro. SETTING: University research laboratory. SUBJECT: The human alveolar epithelial cell line with pulmonary type II (A549) cell properties. INTERVENTIONS: The A549 cells on a polycarbonate porous filter were stimulated either on the apical or the basolateral side with TNF-alpha. To determine TNF-alpha-induced IL-8 production, IL-8 was measured by using a human IL-8 kit in both control and experimental groups. MEASUREMENTS AND MAIN RESULTS: TNF-alpha stimulation induced a large increase in IL-8. When PFC was added to the medium immediately after TNF-alpha stimulation, PFC separated the medium from the cells and IL-8 production was markedly reduced (TNF-alpha alone, 8342+/-470 pg vs. TNF-alpha followed by PFC, 417+/-88 pg, p < .05). Preincubation of A549 cells with PFC for 24 hrs before stimulation with TNF-alpha followed by removal of PFC did not affect IL-8 production (8834+/-204 vs. 8342+/-470 pg; p = NS). When added to the lower chamber, TNF-alpha also induced IL-8 production unaffected by the addition of PFC to the upper chamber. The decrease in TNF-alpha-induced IL-8 production depended on the time of PFC administration after the initiation of TNF-alpha stimulation. The earlier PFC was added, the more pronounced the diminution was in IL-8. CONCLUSIONS: PFC appears to function as a physical barrier, thus reducing cytokines produced by alveolar epithelial cells in vitro. This mechanism may partially explain the decreased inflammatory response observed during liquid ventilation in models of acute lung injury.