大气中细颗粒物对肺癌细胞A549迁移和侵袭作用的影响

采集大连城区大气中可吸入性细颗粒物(PM_(2.5)),研究其对肺癌A549细胞迁移、黏附和侵袭力的影响,利用明胶酶谱法检测细胞分泌的基质金属蛋白酶活性,利用Western blot法测定A549细胞中转移相关蛋白的表达。结果表明,在无明显细胞毒性浓度下,PM_(2.5)可增加A549细胞的迁移速率;细胞与细胞外基质的黏附率增加;细胞侵袭实验结果表明PM_(2.5)可增加A549细胞穿透基底膜的能力;用明胶酶谱法检测发现PM_(2.5)可使A549细胞分泌的基质金属蛋白酶-2(MMP-2)和基质金属蛋白酶-9(MMP-9)活性增强。转移相关蛋白——细胞钙粘蛋白-N(N-cadherin)的表达量升高,而钙粘蛋白-E(E-cadherin)的表达量下降,实验结果表明,PM_(2.5)可增强A549细胞的侵袭性,大气中的可吸入性颗粒可能导致肺癌转移发生率增加。     

天然提取物抗PM2.5诱导A549细胞凋亡的作用

采集北京城区大气可吸人颗粒物中的细颗粒物(PM25),用其对人肺腺癌A549细胞染毒,探讨PM25对细胞增殖的毒性和诱导细胞凋亡的作用,并且考察了加入不同浓度的红豆越橘提取物和竹叶提取物对其的抗性作用.实验采用MTT法检测细胞增殖作用,采用Annexi V-FITC/PI双染法和流式细胞仪检测细胞凋亡.结果显示:PM2...     

运动及不同浓度PM2.5滴注对大鼠糖代谢部分酶活性的影响

为了探讨一次性递增负荷运动及不同浓度细颗粒物(PM2.5)暴露对大鼠己糖激酶(hexokinase,HK)-丙酮酸激酶(pyruvatekinase,PK)及异柠檬酸脱氢酶(isocitratedehydrogenase,IDH)活性影响的机制,将30只雄性Wistar SPF(Specific Pathogen Free,SPF)大鼠随机分为安静(QC)、运动对照组(EC)、低剂量PM2.5+运动组(LPE)、中剂量PM2.5+运动组(MPE)、高剂量PM2.5+运动组(HPE),采用一次性气管滴注染毒后进行递增负荷跑台训练,并通过酶联免疫法(enzyme-linked immunosorbent assay,ELISA)测定大鼠血清及肝脏组织HK,PK,IDH活性。结果表明,与安静组相比,运动对照组HK,PK酶活性下降,IDH活性升高,差异有统计学意义(p0.01)。和EC组相比,LPE,MPE,HPE组各组织中HK,PK,IDH活性均下降,差异有统计学意义(p0.05或p0.01)。实验表明,运动可以降低大鼠的HK,PK活性而增强IDH活性;随着浓度的增加,HK,PK,IDH活性与PM2.5暴露剂量具有相关性降低。     

Mass concentrations and temporal profiles of PM10, PM2.5 and PM1 near major urban roads in Beijing

Mass concentrations of PM₁₀, PM_2.5 and PM₁ were measured near major roads in Beijing during six periods: summer and winter of 2001, winter of 2007, and periods before, during and after the 2008 Beijing Olympic Games. Since the control efforts for motor vehicles helped offset the increase of emissions from the rapid growth of vehicles, the averaged PM_2.5 concentrations at roadsides during the sampling period between 2001 and 2008 fluctuated over a relatively small range. With the implementation of temporary traffic control measures during the Olympics, a clear “V” shaped curve showing the concentrations of particulate matter and other gaseous air pollutants at roadsides over time was identified. The average concentrations of PM₁₀, PM_2.5, CO and NO decreased by 31.2%, 46.3%, 32.3% and 35.4%, respectively, from June to August; this was followed by a rebound of all air pollutants in December 2008. Daily PM₁₀ concentrations near major roads exceeded the National Ambient Air Quality Standard (Grade II) for 61.2% of the days in the non-Olympic periods, while only for 12.5% during the Olympics. The mean ratio of PM_2.5/PM₁₀ near major roads remained relatively stable at 0.55 (±0.108) on non-Olympic days. The ratio decreased to 0.48 (±0.099) during the Olympics due to a greater decline in fine particles than in coarse-mode PM. The ratios PM₁/PM_2.5 fluctuated over a wide range and were statistically different from each other during the sampling periods. The average ratios of PM₁/PM_2.5 on non-Olympic days were 0.71.     

Modelling concentrations of airborne primary and secondary PM10 and PM2.5 with the BelEUROS-model in Belgium

The Eulerian Chemistry-Transport Model BelEUROS was used to calculate the concentrations of airborne PM₁₀ and PM_2.5 over Europe. Both primary as well as secondary particulate matter in the respirable size-range was taken into account. Especially PM_2.5 aerosols are often formed in the atmosphere from gaseous precursor compounds. Comprehensive computer codes for the calculation of gas phase chemical reactions and thermodynamic equilibria between compounds in the gas-phase and the particulate phase had been implemented into the BelEUROS-model. Calculated concentrations of PM₁₀ and PM_2.5 are compared to observations, including both the spatial and daily, temporal distribution of particulate matter in Belgium for certain monitoring locations and periods. The concentrations of the secondary compounds ammonium, nitrate and sulfate have also been compared to observed values. BelEUROS was found to reproduce the observed concentrations rather well. The model was applied to assess the contribution of emissions derived from the sector agriculture in Flanders, the northern part of Belgium, to PM₁₀- and PM_2.5-concentrations. The results demonstrate the importance of ammonia emissions in the formation of secondary particulate matter. Hence, future European emission abatement policy should consider more the role of ammonia in the formation of secondary particles.     

大气细颗粒物对CHO细胞的损伤作用及天然物质的拮抗机制

PM2.5引起的健康危害日益受到广泛关注,但其确切的损伤机理仍不完全清楚,目前也缺乏有效拮抗PM2.5损伤的天然活性物质。因此本文对北京市PM2.5造成CHO细胞的损伤作用及天然物质的拮抗作用进行研究,结果可为PM2.5污染治理和疾病的预防提供科学依据。通过CCK-8法测定细胞存活率;通过流式细胞仪测定细胞凋亡;用荧光探针DCFH-DA法测定ROS;提取细胞内总蛋白并测定其中SOD含量;以及通过Western Blot法分别测定了p-akt/akt、p65及Bad的相对表达量。结果显示:(1)10~40μg·m L-1的PM2.5可明显降低CHO细胞存活率,并呈现极显著的剂量-效应关系(r=-0.964,P0.01);15μg·m L-1PM2.5可以显著增加细胞凋亡、引起细胞内ROS增加、SOD含量下降;p-akt/akt、p65表达量增加说明Akt通路与NF-κB通路均被激活。(2)20μmol·L-1阿魏酸、50μmol·L-1绿原酸和10μmol·L-1荭草素预处理可拮抗PM2.5引起的细胞存活率下降以及细胞凋亡率增加,同时降低细胞内ROS并增加SOD含量,下调p-akt/akt、p65及Bad的相对表达量。其中20μmol·L-1阿魏酸的保护作用最佳。结果说明,PM2.5引起的CHO细胞损伤与细胞凋亡与Akt和NF-κB通路的激活有关;三种天然活性物质具有拮抗PM2.5造成的细胞损伤的能力,其保护机理是通过其降低PM2.5引起的细胞内氧化应激反应,进而降低被PM2.5激活的Akt通路与NF-κB通路和下调Bad蛋白表达量来实现的。     

PM2.5暴露对大鼠行为学及器官的急性毒理作用

通过气管滴注的方法,研究不同浓度细颗粒物(PM2.5)对运动大鼠行为学及不同器官的毒性作用,探讨PM2.5暴露对运动状态下机体的急性毒理作用及其可能的机制。将32只雄性Wistar SPF(Specific Pathogen Free,SPF)大鼠随机分为运动对照组(EC)、低剂量PM2.57.5 mg·(kg·bw)-1+运动组(LPE)、中剂量PM2.515 mg·(kg·bw)-1+运动组(MPE)、高剂量PM2.530 mg·(kg·bw)-1+运动组(HPE)。采用一次性气管滴注染毒后进行递增负荷跑台训练,利用卒中指数对运动过程中大鼠进行行为学评分,并测定大鼠肺、肝脏、股四头肌组织谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px),活性氧(reactive oxygen species,ROS),核转录因子核转录因子kappa B(nuclear factor-B,NF-κΒ)和单核细胞趋化蛋白-1(monocyte chemoattractant protein-1,MCP-1)浓度。与运动对照组相比,3个暴露组中大鼠的卒中指数差异均有统计学意义(p0.05或p0.01);PM2.5暴露组GSH-Px下降,差异均有统计学意义(p0.05或p0.01);ROS,NF-κΒ和MCP-1上升差异均有统计学意义(p0.05或p0.01),并呈现出剂量相关性。急性PM2.5暴露可对大鼠行为学产生不利的影响,导致不同器官的抗氧化及免疫指标发生改变,影响机体的运动能力,造成某些生理损伤。     

卡瓦胡椒素B对人非小细胞肺癌A549细胞的抑制作用

卡瓦胡椒素B是药用植物卡瓦胡椒根中的一种天然查耳酮类化合物,研究了其对人非小细胞肺癌A549细胞的增殖抑制作用及其诱导细胞凋亡的分子机制.实验结果显示,卡瓦胡椒素B能显著抑制非小细胞肺癌A549细胞的增殖,且随着药物浓度的增加、处理时间的延长其抑制作用呈明显的剂量时间效应;同时,卡瓦胡椒素B能显著诱导A549细胞凋亡、细胞周期阻滞于G2-M期;分子机制研究表明,卡瓦胡椒素B能通过活化JNK激酶活性、下调凋亡抑制蛋白survivin的表达以及激活PARP活性从而导致其对A549细胞的增殖抑制作用.结果表明卡瓦胡椒素B对人非小细胞肺癌的预防与治疗可能具有潜在价值.     

Relations between indoor and outdoor PM2.5 and constituent concentrations

Factors impacting indoor-outdoor relations are introduced. Sulfate seems a fine tracer for other non-volatile species. Particulate nitrate and ammonium desorb during outdoor-to-indoor transport. OC load increases during the transport due to sorption of indoor SVOCs. Outdoor PM_2.5 influences both the concentration and composition of indoor PM_2.5. People spend over 80% of their time indoors. Therefore, to assess possible health effects of PM_2.5 it is important to accurately characterize indoor PM_2.5 concentrations and composition. Controlling indoor PM_2.5 concentration is presently more feasible and economic than decreasing outdoor PM_2.5 concentration. This study reviews modeling and measurements that address relationships between indoor and outdoor PM_2.5 and the corresponding constituent concentrations. The key factors in the models are indoor-outdoor air exchange rate, particle penetration, and deposition. We compiled studies that report I/O ratios of PM_2.5 and typical constituents (sulfate (SO₄^2-), nitrate (NO₃^-), ammonium (NH₄⁺), elemental carbon (EC), and organic carbon (OC), iron (Fe), copper (Cu), and manganese (Mn)). From these studies we conclude that: 1) sulfate might be a reasonable tracer of non-volatile species (EC, Fe, Cu, and Mn) and PM_2.5 itself; 2) particulate nitrate and ammonium generally desorb to gaseous HNO₃ and NH₃ when they enter indoors, unless, as seldom happens, they have strong indoor sources; 3) indoor-originating semi-volatile organic compounds sorb on indoor PM_2.5, thereby increasing the PM_2.5 OC load. We suggest further studies on indoor-outdoor relationships of PM_2.5 and constituents so as to help develop standards for healthy buildings.     

北京不同污染天气PM_(2.5)和PM_(10)染毒对大鼠生理病理参数的影响

为探讨北京不同污染天气大气可吸入颗粒物PM_(10)和细颗粒物PM_(2.5)污染对雄性大鼠血常规、氧化损伤、炎症反应和肺组织的影响,将64只雄性8周龄Wistar大鼠随机分为8组,分别为2个对照组(空白组和生理盐水组)和6个染毒组(清洁、雾霾及沙尘暴3种不同天气的PM_(10)染毒组和PM_(2.5)染毒组),每组8只。用2015年3月—5月在北京南海子麋鹿苑采集的清洁、雾霾和沙尘暴3种不同天气的PM_(10)和PM_(2.5)制备悬液,分别采用气管滴入PM_(10)和PM_(2.5)悬液作为染毒组,空白对照组不做任何处理,生理盐水对照组采用气管滴注生理盐水。急性染毒24 h后处死大鼠。采集血液测定18个血常规指标,分析肺泡灌洗液(BALF)中转化生长因子-β1(TGF-β1)、乳酸脱氢酶(LDH)、总抗氧化能力(T-AOC)、白介素-6(IL-6)及肿瘤坏死因子-α(TNF-α)的含量,并在高倍显微镜下观察肺组织和气管病理形态变化。同时,对PM_(10)和PM_(2.5)中的水溶性离子、有机碳/元素碳、16种多环芳烃和7种重金属等元素进行了测定,并分析了各组分与大鼠生理病理指标的相关性。结果表明:清洁、沙尘暴天气的PM_(10)和雾霾天气的PM_(2.5)急性染毒导致大鼠白细胞系参数即免疫力显著下降。污染天气颗粒物染毒后大鼠BALF氧化炎症因子的改变表明呼吸系统受到感染:沙尘暴和清洁天的PM_(10)染毒均显著提高了TGF-β1,雾霾PM_(10)染毒后IL-6和LDH有一定程度升高。3种天气颗粒物染毒对肺和气管造成的组织病理伤害各有特点,但PM_(2.5)伤害程度普遍大于PM_(10)。染毒颗粒物粒径大小,其化学成分类别、浓度是造成大鼠血常规指标变化、氧化炎症反应和组织学病变的可能原因。