RNA干扰对活化的小鼠巨噬细胞肿瘤坏死因子α表达的影响

目的：观察靶向小鼠肿瘤坏死因子α（TNF-α）基因的小干扰RNA（siRNA）在体外对小鼠巨噬细胞系RAW264．7表达TNF-α的抑制作用。方法：采用化学法合成针对TNF-α mRNA不同位点设计的3条siRNA序列（siRNA1～3）和1条带有荧光标记的BLOCK—IT^TM荧光Oligo（修饰的荧光标记的dsRNA,siRNA4）通过脂质体包裹后将其分别转染至小鼠巨噬细胞系RAW264．7,同时设立1个无任何靶基因的siRNA作为阴性对照（siRNA4）。荧光显微镜下观察siRNA的转染效率;用实时荧光定量PCR和酶联免疫吸附实验（ELISA）法分别检测siRNA对TNF-α的mRNA和蛋白表达的抑制作用。结果：内毒素刺激后6h,巨噬细胞表达TNF-α mRNA和合成分泌的TNF-α量均增加,于9～12h达高峰。利用荧光标记的Oligo观察到siRNA转染效率达72％～80％。siRNA1～4转染巨噬细胞后,siRNA2、3可见内毒素刺激的TNF-α mRNA（0．158±0．030、0．114±0．028）和TNF-α蛋白表达[（1355±348）pg／ml、（817±138）pg／m1]均明显少于未转染组[TNF-α mRNA0．294±0．147,蛋白（2104±32）pg／ml,均P〈0．05],其中siRNA3的抑制率非常显著,达61．2％（P〈0．01）。阴性对照siRNA4对细胞基因及蛋白表达无影响。结论：内毒素可刺激小鼠巨噬细胞TNF-α的合成。化学合成siRNA转染小鼠巨噬细胞能有效抑制TNF-α mRNA及蛋白的表达。     

氯胺酮对内毒素诱导大鼠急性肺损伤的影响及其机制

目的探讨不同剂量氯胺酮对内毒素（LPS）诱导大鼠肺损伤的影响和作用机理。方法48只雄性Wistar大鼠随机分为4组：对照组,LPS组（5mg／kg）,低剂量氯胺酮治疗组（5mg／kg）,高剂量氯胺酮治疗组（10mg／kg）,每组12只。建立内毒素诱导的大鼠急性肺损伤模型,于注射LPS后4h处死大鼠,测肺湿／干重比,观察支气管肺泡灌洗液（BALF）中性粒细胞计数比、蛋白浓度,测肺组织中肿瘤坏死因子α（TNF-α）、白细胞介素-8（IL-8）、NO水平。RT．PCR测肺组织中．NOSmRNA表达,Western-blot测肺组织中NF-κB蛋白表达。结果LPS组大鼠肺湿／干重比、BALF中性粒细胞计数比、蛋白浓度均明显增加（P〈0．01）,肺组织中TNF-α、IL-8、NO水平显著性升高（P〈0.01）,同时肺组织中iNOSmRNA和核因子-κB（NF-κB）蛋白表达均增加。而氯胺酮治疗组的各项指标均较LPS组减轻,大剂量组作用更明显。结论氯胺酮通过抑制NF-κB表达,减少炎症性细胞因子的产生,从而对内毒素（LPS）诱导的大鼠肺损伤有一定保护作用。     

Immunological status of alveolar macrophages in patients with lung cancer and benign pulmonary diseases]

This is a report of the study on the immunological status of alveolar macrophages (aM phi) in patients with lung cancer (LC, n = 27) and benign pulmonary diseases (BD, n = 26). Patients were undergone bronchoalveolar lavage by fiberoptic bronchoscopy. aM phi in the lavage fluid isolated by adherence on plastic surface were examined in vitro for their cytostatic and cytolytic activities against tumor target cells, secretion of interleukin 1 (IL-1) and tumor necrosis factor (TNF), intracellular IL-1 activity and mRNA expression of IL-1 beta and TNF-alpha. aM phi, both non-activated and activated, were shown to be highly cytostatic against P815 cells by 3H-TdR post-labelling assay. There was no statistical difference between the LC and BD group. As shown by isotope release assay, regardless of being activated or not, aM phi were not cytolytic against P815 and NS-1 cells in both groups of patients. TNF activity could be demonstrated in the culture supernatants of aM stimulated with LPS. Statistically, the TNF activity was not different in the two groups of patients. Spontaneous release of TNF activity was occasionally detected in unstimulated aM phi. While both intracellular and extracellular IL-1 activity of unstimulated aM phi was demonstrated in the two patient groups, the former activity was 1 to 5 times as high as the latter. When stimulated with LPS, there was some increase in extracellular but not intracellular IL-1 activity. mRNA expression of IL-1 beta and TNF-alpha by dot blot hybridization was demonstrable in aM phi from both patient groups irrespective of activation. These results indicate that the immune status of aM phi in lung cancer patients examined does not differ from that in patients with benign pulmonary diseases.     

异丙酚预处理对脂多糖（LPS）诱导的人肺微血管内皮细胞（HPMVCs）血管紧张素转化酶（ACE）的表达与活性的影响

 目的 在脂多糖(lipopolysaccharide,LPS)诱导的人肺微血管内皮细胞(human pulmonary microvascular endothelial cells,HPMVCs)损伤模型中,观察异丙酚预处理对血管紧张素转化酶(angiotensin-converting enzyme,ACE)的影响,探讨异丙酚肺保护作用的可能机制。方法 以体外培养的HPMVCs 3~5代作为实验对象,将细胞随机分为4组(n=8)：对照组(C组)、异丙酚组(P组)、LPS组(L组)和异丙酚预处理组(P+L组)。药物终浓度：LPS 5 μg/mL,异丙酚50 μmol/L。按上述分组,加入LPS前1 h加入异丙酚。于37℃、5％CO₂培养箱中进行培养。分别培养12、24、48、72 h后采用CCK-8 (Cell Counting Kit-8)法测细胞活力。细胞孵育12 h后,采用改良分光光度法检测各组培养液和细胞中的ACE活性,real-time PCR检测ACE、TNF-α、IL-1β和MCP-1 mRNA表达水平,同时ELISA测定细胞培养液中TNF-α、IL-1β和MCP-1的蛋白含量。结果 (1)各组细胞在72 h内的细胞活力无显著差异(P>0.05);(2)与C组相比,P组各检测指标均无显著差异(P>0.05);(3)与C组相比,L组TNF-α、IL-1β和MCP-1的蛋白含量及其基因表达水平均显著升高,分泌型ACE活性增加,细胞ACE活性降低,ACE mRNA表达下调(P<0.05);(4)与L组相比,P+L组分泌的TNF-α、IL-1β和MCP-1及其mRNA表达显著降低,细胞ACE活性增加,ACE mRNA表达上调(P<0.05),分泌型ACE活性不变(P>0.05)。结论 异丙酚在转录水平调节HPMVCs中ACE的表达,可能是异丙酚保护HPMVCs的作用机制之一。     

八肽胆囊收缩素对脂多糖诱导RAW264.7细胞IL-1β、IL-6、IL-10表达的影响

目的 研究脂多糖(lipopolysaccharide,LPS)诱导RAW 264.7细胞促炎性细胞因子IL-1β、IL-6及抗炎性细胞因子IL-10的动态变化规律及八肽胆囊收缩素(cholecystokinin octapeptide,CCK.-8)对其表达的影响.方法 LPS诱导RAW 264.7细胞不同时间(0、...     

糖皮质激素对内毒素致急性肺损伤大鼠肺组织Fractalkine表达的影响

目的动态观察内毒素（LPS）所致急性肺损伤（acute lung injury,ALI）大鼠肺组织内趋化因子Fractalkine（FKN）的表达变化,及糖皮质激素对其的影响。方法将42只大鼠随机分为空白对照组、模型组（LPS）及地塞米松干预组（DEX）,其中LPS组和DEX组再分为1h、2h、4h3个时相组,每组6只,LPS组和DEX组大鼠经尾静脉注射LPS（4mg／kg）建立ALI大鼠模型。采用ELISA、RT—PCR等方法,观察ALI大鼠模型肺组织病理学改变、肺湿干重比值（W／D）及血清TNF-a变化,并检测肺组织FKNmRNA的表达,同时观察地塞米松对上述指标的影响．结果模型组1h、2h与4h3个时相组肺损伤病理改变、肺W／D、血浆TNF—α均明显增高,地塞米松能减轻ALl大鼠肺组织炎症反应、肺W／D值及血清TNF—α水平（P均〈0．05）。正常大鼠肺组织FKNmRNA有表达,模型组3个时相亚组肺组织FKNmRNA表达较正常组明显增加（P〈0．05）,在2h时点达峰值,地塞米松能下调ALI大鼠肺组织FKNmRNA表达（P〈0．05）。FKNmRNA的表达量与血清TNF—α水平呈正相关（r=0．674,P〈0．05）．结论早期应用地塞米松可降低TNF-α水平,下调肺组织FKN mRNA的表达,这可能是糖皮质激素对内毒素致急性肺损伤实验大鼠保护作用机制之一。     

苯并噁唑类化合物K310对LPS刺激RAW264.7巨噬细胞的抗炎作用

目的 探索K310对脂多糖(LPS)诱导RAW264.7巨噬细胞的抗炎作用及机制.方法 在LPS诱导RAW264.7巨噬细胞的模型基础上,采用CCK-8方法检测不同浓度K310对RAW264.7巨噬细胞活性的影响;Griess试剂检测K310对一氧化氮(NO)的影响;酶联免疫吸附法(ELISA)检测K310对IL-6炎性因子的影响;荧光定量PCR方法检测K310对诱导型一氧化氮(iNOS)和IL-6基因表达的影响;荧光免疫印迹法(Western bolt)检测K310对磷酸化的NF-kB和ERK1/2蛋白的影响.结果 K310(5、10和20 μM)不影响LPS刺激RAW264.7巨噬细胞的活性;与LPS刺激组比较,K310不仅能显著抑制NO和IL-6的炎性因子及炎性基因;还能抑制磷酸化的NF-kB和ERK1/2蛋白的表达.结论 K310对LPS诱导RAW264.7巨噬细胞的炎症具有抗炎作用,其作用机制可能是K310通过抑制NF-kB和MAPK信号通路,从而抑制NO和IL-6炎性因子的产生.     

丝裂原活化蛋白激酶通路对脂多糖诱导RAW264.7细胞肿瘤坏死因子α基因表达的协同调节作用

目的 探讨脂多糖（LPS）诱导RAW264.7细胞肿瘤坏死因子α(TNF-α)基因表达过程中丝裂原活化蛋白激酶（MAPK）通路的协同调节作用及其分子机制。方法 用蛋白激酶活性测定分析LPS刺激RAW264．7细胞引起的激酶活性变化;用报告基因技术和反转录聚合酶链反应（RT－PCR）方法研究LPS诱导的TNF－α基因转录的分子机制。结果 LPS刺激RAW264．7细胞可引起细胞外信号调节激酶1（ERK1）、c-Jun氨基末端激酶1（JNK1）和p38MAPK的一过性激活,用MAPK上游激酶的活性突变体分别转染RAW264．7均可不同程度地诱导TNF－α启动子转录活性;而且,这些MAPK通路激活诱导的TNF－α启动子转录活性表现出明显的协同效应;三种MPAPK的无活性突变体均显示出对LPS刺激引起的TNF－α启动子转录激活的抑制效应;RT－PCR的结果证实,ERK、JNK和p38MAPK的特异性抑制剂对TNF－αmRNA表达具有不同程度的抑制作用。结论 LPS刺激引起的TNF－α启动子转录活性增加,可能涉及了ERK、p38和JNK三条通路的激活;这些通路通过协同效应共同发挥对TNF－α基因表达的调控。     

Induction of type Ⅱ alveolar epithelial cells apoptosis in mouse by lipopolysaccharide does not require TNF-α

Objective To examine whether lipopolysaccharide (LPS)-induced apoptosis correlates with TNF-α release by type Ⅱ alveolar epithelial cells (AEC Ⅱ), whether TNF-α knockout (TNF KO) abrogates the induction of apoptosis by LPS and whether TNF-α is sufficient to induce apoptosis in this cell type.Methods AEC Ⅱ were isolated from wild type mice and TNF KO mice. Cells were stimulated with LPS or recombinant murine TNF-α for 24 h. TNF-α in culture supernatant was determined by ELISA following LPS stimulation. Apoptosis was determined by the terminal deoxynucleotidyl transferase end-labeling (TUNEL) assay after treatment with either LPS or TNF-α. Results LPS induced apoptosis in wild type AEC Ⅱ in a concentration-dependent manner. LPS-induced AEC Ⅱ apoptosis was accompanied by an 11-fold increase (from 0.073±0.065 ng/ml in control to 0.94±0.14 ng/ml in 50 μg/ml of LPS, P&lt;0.01) in TNF-α release. However, increasing concentrations (5 or 25 ng/ml) of recombinant murine TNF-α failed to induce AEC Ⅱ apoptosis. In addition, apoptosis did occur in AEC Ⅱ isolated from TNF KO mice following LPS stimulation.Conclusions This study confirms that LPS induces TNF-α release and apoptosis in murine AEC Ⅱ in vitro. Exogenous TNF-α failed to induce AEC Ⅱ apoptosis, and apoptosis occurred following LPS stimulation in cells lacking the ability to produce TNF-α. Taken together, these results suggest that LPS-induced AEC Ⅱ apoptosis occurs by a TNF-α-independent mechanism.