A549细胞对壳寡糖及其纳米粒的摄取作用

目的研究壳寡糖及其纳米粒的A549肺上皮细胞摄取作用,探讨壳寡糖纳米粒作为药物载体的可能性。方法溶剂扩散法制备壳寡糖纳米粒,以A549肺上皮细胞评价壳寡糖及其纳米粒的细胞毒性,由荧光倒置显微镜、流式细胞仪研究A549细胞对壳寡糖及其纳米粒的摄取作用。结果壳寡糖及其纳米粒的细胞毒性均较低,IC₅₀分别为944.36和643.16 mg·L^-1。壳寡糖及其纳米粒的细胞摄取作用与其浓度及细胞孵育时间相关;在同一孵育时间壳寡糖纳米粒的摄取量比等浓度的壳寡糖增加0.49～13.9倍。结论壳寡糖及其纳米粒的细胞毒性较低。壳寡糖形成纳米粒后,可显著增加A549细胞的摄取作用。     

A549细胞对单硬脂酸甘油酯固体脂质纳米粒的摄取作用A549细胞对单硬脂酸甘油酯固体脂质纳米粒的摄取作用

目的考察单硬脂酸甘油酯固体脂质纳米粒(monostearin solid lipid nanoparticles，MSLN)经PEG2000修饰后，对A549细胞摄取MSLN及J774A1细胞吞噬MSLN的影响。方法采用溶剂扩散法制备MSLN，测定其粒径和zeta电位；以罗丹明B(Rhodamine B)为荧光标记物，研究A549细胞对MSLN的摄取作用和J774A1细胞对MSLN的吞噬作用。结果MSLN的细胞毒性较低，A549细胞对MSLN的摄取可快速接近饱和，其摄取百分率与MSLN在细胞外的浓度呈负相关。结论MSLN经PEG2000修饰，可显著抑制J774A1细胞对MSLN的吞噬，但可增加A549细胞对MSLN的摄取。     

Uptake of Chitosan and Associated Insulin in Caco-2 Cell Monolayers: A Comparison Between Chitosan Molecules and Chitosan Nanoparticles

PURPOSE: To evaluate the uptake of chitosan molecules (fCS) and nanoparticles (fNP), and their ability to mediate insulin transport in Caco-2 cell monolayers. METHODS: Cell-associated fCS and fNP were evaluated by fluorometry, trypan blue quenching, and confocal microscopy using FITC-labeled chitosan. Chitosan-mediated transport of FITC-labeled insulin was studied in Caco-2 cell monolayers cultured on permeable inserts. RESULTS: Caco-2 cells showed twofold higher association with fNP than fCS after 2-h incubation with 1 mg/ml samples. fNP uptake was a saturable (Km 1.04 mg/ml; Vmax 74.15 microg/mg/h), concentration- and temperature-dependent process that was inhibited by coadministered chlorpromazine. fCS uptake was temperature dependent, but was less sensitive to concentration and was inhibited by filipin. Postuptake quenching with 100 microg/ml of trypan blue suggests a significant amount of intracellular fNP, although the bulk of fCS was extracellular. Internalized fNP were located by confocal microscopy at 15 microm from the apical membrane, but there was no apparent breaching of the basal membrane. This might explain the failure of the nanoparticles to mediate significant insulin transport across the Caco-2 cell monolayer. CONCLUSIONS: Formulation of chitosan into nanoparticles transforms its extracellular interactions with the Caco-2 cells to one of cellular internalization via clathrin-mediated endocytosis.     

Effects of fullerene C60 nanoparticles on A549 cells

Fullerene C₆₀ nanoparticles (C₆₀ NPs) have been widely applied in many fields due to their excellent physical and chemical properties. As production and applications of C₆₀ NPs expand, public concern about the potential risk to human health has also risen. The toxicity of C₆₀ NPs was evaluated by the CCK-8 assay using the cultured human epithelial cell line A549. Cellular uptake of the C₆₀ NPs was observed by TEM imaging. In our findings, C₆₀ NPs could readily enter A549 cells and showed no significant toxicity. Exposure of cultured A549 cells to C₆₀ NPs led to an increase of intracellular reactive oxygen species (ROS) while glutathione reductase activity was probably activated to generate more GSH to maintain a cellular oxidation–reduction equilibrium. The A549 cells responded to the ROS increases through the inauguration of autophagic responses, aimed at restoring cellular health and equilibrium.     

异鼠李素诱导A549细胞凋亡的研究

目的观察异鼠李素是否能诱导人肺腺癌细胞株A549细胞凋亡及相关基因的变化。方法20μg/ml异鼠李素处理A549细胞,光镜电镜下观察细胞形态;进行集落形成实验,MTT法测细胞生长抑制率;流式细胞仪检测凋亡峰及bax,bcl-2等凋亡相关基因的表达。结果10～640μg/ml异鼠李素可抑制A549细胞生长,抑制率有剂量依赖性。流式细胞仪检测20μg/ml异鼠李素处理后出现明显凋亡峰;药物可使bax表达上调,bcl-2表达明显下降,表达改变有浓度依赖性。结论异鼠李素可抑制A549细胞生长,诱导其凋亡,其诱导凋亡的作用与凋亡相关基因抗凋亡基因bcl-2表达明显下调,bax表达上调有关。     

Uptake of oleoyl-chitosan nanoparticles by A549 cells

The aim of the present study was to evaluate cellular uptake of oleoyl-chitosan (OCH) nanoparticles by using A549 cells, a human lung carcinoma cell line, for drug and gene delivery applications. In this study, self-assembled OCH nanoparticles encapsulating a fluorescent marker molecule, fluorescein isothiocyanate (FITC), were prepared and characterized. The effects of particle size, concentration, and incubation time on the cellular uptake of the nanoparticles (FITC-OCH nanoparticles) were quantified by spectrofluorometric measurement and confirmed using fluorescence microscopy studies. The nanoparticles were taken up by the cells, and levels of binding and uptake increased with the decrease of particle size and the increase of particle concentration and incubation time. These results implied that the OCH nanoparticles have great potential to be applied as a drug carrier system to deliver drugs into the cells.     

Chloroquine rescues A549 cells from paraquat-induced death

Paraquat (PQ) is a widely used herbicide associated with a high mortality rate, yet, there are no effective treatments for PQ poisoning. PQ may damage alveolar type II cells leading to moderate to severe acute respiratory distress syndrome (ARDS). The present study was undertaken to show that PQ causes alveolar type II (A549) cell death and to evaluate whether chloroquine (CQ) can protect A549 cells against PQ-induced cell death. The results showed that high concentrations of PQ resulted in toxicity, as indicated by a decrease in cell viability. More importantly, for the first time, CQ was found to improve cell viability of PQ treated A549 cells. Moreover, our data demonstrated that CQ increased lysosome-associated membrane protein-1, lysosome-associated membrane protein-2 and light chain-3 expressions, suggesting that the mechanism by which CQ rescues PQ-induced cytotoxicity may be through protection of the lysosomal membrane or up-regulation of autophagy. In conclusion, our study indicates that CQ may be used as a potential drug to rescue PQ-induced ARDS.     

白藜芦醇诱导肺腺癌A549细胞凋亡的作用机制

目的 探讨白藜芦醇（Res）对肺腺癌A549细胞凋亡的作用及其机制。方法 常规培养肺腺癌A549细胞（购于中国科学院细胞生物学研究所）至对数生长期,加入不同浓度的Res （终浓度分别为3、10、30、60、100、200、300 mg/L）,以Res 0 mg/L为对照组,采用噻唑蓝（MTT）比色法检测不同浓度的Res对A549细胞的吸光度值,计算细胞的生长抑制率;采用Annexin-Ⅴ/PI双染法检测Res对肺腺癌A549细胞凋亡的影响;采用逆转录酶-聚合酶联反应（RT-PCR）检测端粒酶mRNA和β-actin mRNA的相对活性。结果 MTT检测显示Res呈剂量依赖性抑制A549细胞增殖。与对照组比较,不同浓度（10、30、100 mg/L） Res可抑制A549细胞增殖;Annexin-Ⅴ/PI检测结果显示,与对照组比较,随着Res剂量（10、30、100 mg/L）的增加,A549细胞的凋亡数升高,差异有统计学意义（P<0.05）;与对照组比较,不同剂量Res （10、30、100 mg/L）诱导端粒酶mRNA相对含量明显下降,差异有统计学意义（P<0.05）。结论 Res可诱导肺腺癌A549细胞凋亡,其机制可能与抑制端粒酶活性有关。     

Toxicity of ZnO nanoparticles (NPs) to A549 cells and A549 epithelium in vitro: Interactions with dipalmitoyl phosphatidylcholine (DPPC)

Once inhaled, nanoparticles (NPs) will first interact with lung surfactant system, which may influence the colloidal aspects of NPs and consequently the toxic potential of NPs to pulmonary cells. In this study, we investigated the effects of dipalmitoyl phosphatidylcholine (DPPC), the major component in lung surfactant, on stability and toxicity of ZnO NPs. The presence of DPPC increased the UV–vis spectra, hydrodynamic size, Zeta potential and dissolution rate of ZnO NPs, which indicates that DPPC might interact with NPs and affect the colloidal stability of NPs. Exposure to ZnO NPs induced cytotoxicity associated with increased intracellular Zn ions but not superoxide in A549 cells. In A549 epithelium model, exposure to ZnO NPs induced cytotoxicity and decreased the release of interleukin 6 (IL-6) without a significant effect on epithelial permeability rate. Co-exposure of A549 cells or A549 epithelium model to DPPC and ZnO NPs induced a higher release of lactate dehydrogenase (LDH) and interleukin-6 (IL-6) compared with the exposure of ZnO NPs alone. We concluded that the presence of DPPC could influence the colloidal stability of ZnO NPs and increase the damage of NPs to membrane probably due to the increased positive surface charge.     

Reactive oxygen species mediated DNA damage in human lung alveolar epithelial (A549) cells from exposure to non-cytotoxic MFI-type zeolite nanoparticles

Increasing utilization of engineered nanoparticles in the field of electronics and biomedical applications demands an assessment of risk associated with deliberate or accidental exposure. Metal based nanoparticles are potentially most important of all the nanoparticles in terms of health risks. Microporous alumino-silicates and pure silicates named as zeolites and zeo-type materials with variety of structures, chemical compositions, particle sizes and morphologies have a significant number of industrial uses such as in catalysis, sorption and ion-exchange processes. In particular, the nanosized particles due to their unique properties are used in hybrid organic-inorganic materials for photography, photonics, electronics, labeling, imaging, and sensing. The aim of the current study is to investigate pure silica MFI-type zeolites nanoparticles with sizes of 50 nm and 100 nm (samples MFI-50 and MFI-100) under suspended conditions and their toxicological effects on human lung alveolar (A549) cells under in vitro conditions.     

PM2.5-induced oxidative stress triggers autophagy in human lung epithelial A549 cells

Exposure to higher levels of air pollution particulate matter (PM) with an aerodynamic diameter of less than 2.5 μm (PM_2.5) links with an increased risk of cardiovascular and respiratory deaths and hospital admission as well as lung cancer. Although the mechanism underlying the correlation between PM_2.5 exposure and adverse effects has not fully elucidated, PM_2.5-induced oxidative stress has been considered as an important molecular mechanism of PM_2.5-mediated toxicity. In this work, human lung epithelial A549 cells were used to further investigate the biological effects of PM_2.5 on autophagy. The cell viability showed both time- and concentration-dependent decrease when exposure to PM_2.5, which can be attributed to increase of the levels of extracellular lactate dehydrogenase (LDH) release and intracellular reactive oxygen species (ROS) generation in A549 cells. Moreover, PM_2.5-induced oxidative damage in A549 cells was observed through the alteration of superoxide dismutase (SOD) and catalase (CAT) activities compared to the unexposed control cells. PM_2.5-induced autophagy was indicated by an increase in microtubule-associated protein light chain-3 (LC3) puncta, and accumulation of LC3 in both time- and concentration-dependent manner. PM_2.5-induced mRNA expression of autophagy-related protein Atg5 and Beclin1 was also observed compared with those of the unexposed control cells. These results suggest the possibility that PM_2.5-induced oxidative stress probably plays a key role in autophagy in A549 cells, which may contribute to PM_2.5-induced impairment of pulmonary function.     

阿霉素热化疗诱导A549细胞凋亡及线粒体跨膜电位的变化

目的 :探讨阿霉素 (adrimycin ,ADM)热化疗诱导人肺腺癌A5 49细胞凋亡及对线粒体跨膜电位(Δψm)的影响。 方法 :不同浓度的阿霉素作用于体外培养的A5 49细胞 ,4 2 .5℃作用 30min后 ,37℃继续培养 ,在不同时间内检测。用电镜、MTT法、流式细胞仪检测。结果 :阿霉素热化疗明显增强对A5 49细胞的抑制作用 ,细胞内阿霉素的浓度显著高于化疗组 (P <0 .0 1) ;阿霉素浓度为 1.0 ,2 .0mg·L-1时 ,热化组与化疗组比较 ,凋亡率增高 ,线粒体膜电位下降 (P <0 .0 1)。结论 :线粒体跨膜电位下降可能是ADM热化疗诱导A5 49细胞凋亡的关键     

羧甲司坦对香烟烟雾提取物诱导A549细胞炎性损伤的影响

目的：探讨羧甲司坦抑制香烟烟雾提取物（CSE）诱导A549细胞炎性损伤的作用。方法：传代培养人A549细胞并分为5组：对照组,CSE组,羧甲司坦低、中、高剂量组（予不同浓度羧甲司坦孵育和CSE诱导）。qRT-PCR、ELISA检测主要细胞因子的合成和释放,免疫蛋白印迹（Western-blot）、免疫荧光（IF）观察NF-κB及MAPK相关信号通路的活化情况。结果：以羧甲司坦预处理或后处理,均可降低CSE诱导的A549细胞的IL-6、IL-8和MIP-1β mRNA的表达;降低IL-6及IL-8的释放。羧甲司坦预处理可抑制p65入核。Western-blot结果显示,对照组,CSE组,羧甲司坦低、中、高剂量组的P-p65蛋白相对表达量分别为（0.17±0.05）、（0.90±0.19）、（0.68±0.15）、（0.64±0.12）和（0.57±0.13）,pERK1/2蛋白相对表达量分别为（0.30±0.10）、（1.25±0.33）、（1.01±0.19）、（0.89±0.22）和（0.81±0.18）,CSE组均明显高于对照组,羧甲司坦低、中、高剂量组均明显低于CSE组（P<0.05）。结论：羧甲司坦通过抑制NF-κB p65及ERK1/2 MAPK活化,发挥对CSE诱导的A549细胞炎性损伤的保护作用。     

hBD2对SP感染的A549细胞凋亡的影响

目的 观察人β-防御素2(hBD2)对肺炎链球菌(SP)感染人肺腺癌细胞(A549)细胞凋亡的影响。方法 建立SP感染A549细胞模型,hBD2以10、20和30ng/mL的浓度梯度干预该模型,观察细胞形态变化,CCK-8法检测细胞活力,qRT-PCR检测细胞Bax、Bcl-2及caspase-3mRNA表达,免疫细胞化学法检测细胞Bax、Bcl-2蛋白的表达。结果 SP感染引起A549细胞皱缩、空泡化,hBD2一定程度上保护细胞活力,抑制Bax表达,上调Bcl-2的表达。结论 hBD2对SP感染的A549细胞凋亡具有保护作用。     

西瑞香素对肺癌A549细胞侵袭及迁移能力的影响

目的探讨西瑞香素对肺癌A549细胞侵袭及迁移能力的影响。方法通过Transwell小室分析西瑞香素对肺癌A549细胞侵袭能力的影响;划痕实验检测西瑞香素对肺癌A549细胞迁移能力的影响;Western blotting检测西瑞香素作用于A549细胞后MMP-2、MMP-9侵袭相关蛋白的表达。结果 Transwell小室实验结果提示,西瑞香素对A549细胞侵袭能力有抑制作用;划痕实验结果提示,西瑞香素对A549细胞迁移能力有抑制作用;Western blotting结果提示,西瑞香素抑制MMP-2、MMP-9侵袭相关蛋白的表达。随着药物浓度增加,MMP-2、MMP-9表达减少,具有剂量依赖性。结论西瑞香素对A549细胞体外侵袭及迁移有抑制作用,这种作用与抑制MMP-2、MMP-9表达有关。     

Ceramide induces apoptosis in human lung adenocarcinoma A549 cells through mitogen-activated protein kinases

AIM: To provide experimental data for further research on the signal transduction of apoptosis in lung adenocarcinoma cells, we examined the effects of exogenous C2-ceramide administration on several members of the mitogen-activated protein kinase (MAPK) superfamily and caspase-3 in A549 cells. METHODS: Cell viability and apoptosis were analyzed by cell counting kit-8 assay and flow cytometry. Various MAPK and caspase-3 proteins were detected by Western blotting. RESULTS: C2-ceramide selectively altered the phosphorylation state of members of the MAPK superfamily, causing hyperphosphorylation of mitogen-activated protein kinase kinase (MEK)1/2 and the p38 MAPK, but not affecting the phosphorylation of extracellular signal-regulated kinase 1/2 and the c-Jun N-terminal kinase. SB-203580 (a p38 MAPK inhibitor) and p38 siRNA, but not U0126 (a MEK inhibitor), partially rescued cell death induced by C2-ceramide. C2-ceramide promoted the activation of caspase-3. CONCLUSION: Exogenous C2-ceramide induced apoptosis in human lung adenocarcinoma A549 cells. The activation of MAPK and caspase-3 were involved in the mechanisms of C2-ceramide-induced apoptosis in A549 cells.     

An integrative cellular metabolomic study reveals downregulated tricarboxylic acid cycle and potential biomarkers induced by tetrabromobisphenol A in human lung A549 cells

Tetrabromobisphenol A (TBBPA) is extensively utilized as a brominated flame retardant in numerous chemical products. As an environmental contaminant, the potential human toxicity of TBBPA has been attracting increasing attention. Nonetheless, the exact underlying mechanisms of toxicological effects caused by TBBPA remain uncertain. In this study, we investigated the potential mechanisms of TBBPA toxicity in vitro in the A549 cell line, one of the widely used type II pulmonary epithelial cell models in toxicology research. Cell viability was determined after treatment with varying concentrations of TBBPA. Liquid chromatography–mass spectrometry (LC–MS) metabolomics and metabolic flux approaches were utilized to evaluate metabolite and tricarboxylic acid (TCA) cycle oxidative flux changes. Our findings demonstrated that TBBPA significantly reduced the viability of cells and attenuated mitochondrial respiration in A549 cells. Additionally, LC–MS data showed significant reductions in TCA cycle metabolites including citrate, malate, fumarate, and alpha-ketoglutarate in 50 μM TBBPA-treated A549 cells. Metabolic flux analysis indicated reduced oxidative capacity in mitochondrial metabolism following TBBPA exposure. Moreover, diverse metabolic pathways, particularly alanine, aspartate, and glutamate metabolism and the TCA cycle, were found to be dysregulated. In total, 12 metabolites were significantly changed (p < .05) in response to 50 μM TBBPA exposure. Our results provide potential biomarkers of TBBPA toxicity in A549 cells and help elucidate the molecular mechanisms of pulmonary toxicity induced by TBBPA exposure.     

阻断Notch信号途径能有效抑制A549细胞增殖

目的 Delta-like 4(DLL4)是Notch信号通路的配体之一,是近年新发现的血管生长调控因子,研究表明DLL4的高表达与肺腺癌转移预后密切相关。该文旨在研究DLL4在A549细胞中的表达,以及DLL4基因表达对人A549细胞增殖与凋亡的影响。方法 (1)体外培养A549细胞,免疫细胞化学法检测DLL4在A549细胞中的表达及定位;(2)设计并化学合成靶向DLL4基因的siRNA序列,lipofectamineTM2000介导DLL4 siRNA转染A549细胞,RT-PCR进行DLL4-mRNA定量,Western blot分别检测A549细胞DLL4蛋白的改变;(3)四甲基偶氮唑盐(MTT)比色法检测细胞的存活和生长变化;(4)激光共聚焦显微镜检测Annexin V-FITC标记的A549细胞的细胞凋亡比率。结果 (1)A549细胞表达DLL4蛋白,且定位于胞浆中;(2)DLL4-mRNA和DLL4蛋白的表达在对照组与干扰组之间有显著差异(P0.05);(3)MTT检测显示抑制DLL4表达对A549细胞的增殖有抑制作用,DLL4干扰组细胞增殖抑制率为43.85%,未处理组细胞增殖抑制率为23.81%;(4)抑制DLL4基因表达,A549细胞的凋亡比率明显升高,DLL4干扰组细胞凋亡率为(25.01±4.32)%,未处理组细胞凋亡率为(14.24±0.98)%。结论 DLL4在A549细胞表达。特异性阻断DLL4/Notch信号途径能有效抑制A549细胞增殖,促进细胞凋亡。