Alveolar Epithelial Cell Injury Due to Zinc Oxide Nanoparticle Exposure
Alveolar Epithelial Cell Injury Due to Zinc Oxide Nanoparticle Exposure
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DOI：
10.1164/rccm.201002-0185oc
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发表时间：
2010-12-01
影响因子：
24.7
通讯作者：
Crandall, Edward D.
中科院分区：
文献类型：
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作者：
Kim, Yong Ho;Fazlollahi, Farnoosh;Crandall, Edward D.
基本原理：尽管已知吸入氧化锌（ZnO）纳米颗粒（NP）会引起全身性疾病（即，目的：通过将原代培养的大鼠肺泡上皮细胞单层（RAECMs）暴露于ZnO NPs，研究ZnO NPs诱导的肺泡上皮细胞损伤。方法：将RAECMs顶部暴露于ZnO NPs，或者在一些实验中，暴露于含有ZnCl 2或从ZnO NPs释放的游离Zn的培养液。跨上皮电阻（R-T）和等效短路电流（I-EQ）作为浓度和时间的函数进行评估。形态学变化，乳酸脱氢酶释放，细胞膜的完整性，细胞内活性氧（ROS），和线粒体activitywere measured.Measurements和主要结果：顶端暴露于176 μ g/ml ZnO纳米颗粒减少R-T和I-EQ的RAECMs的100%超过24小时，而暴露于11 μ g/ml ZnO纳米颗粒几乎没有影响。由176 μ g/ml ZnO纳米颗粒引起的R-T和I-EQ的变化是不可逆的。ZnO NP对R-T的作用产生约20 μ g/ml的半最大浓度。根尖暴露于176 μ g/ml ZnO纳米颗粒24小时，诱导线粒体活性降低，乳酸脱氢酶释放增加，荧光素磺酸渗透性增加，细胞内ROS增加，ZnO纳米颗粒从根尖液转移到基底外侧液（最有可能穿过受损的细胞和/或受损的细胞旁途径）。结论：ZnO纳米颗粒以剂量和时间依赖性方式对RAECMs造成严重损伤，至少部分由ZnO纳米颗粒释放的游离Zn、线粒体功能障碍和细胞内ROS增加介导。
Rationale: Although inhalation of zinc oxide (ZnO) nanoparticles (NPs) is known to cause systemic disease (i.e., metal fume fever), little is known about mechanisms underlying injury to alveolar epithelium.Objectives: Investigate ZnO NP-induced injury to alveolar epithelium by exposing primary cultured rat alveolar epithelial cell monolayers (RAECMs) to ZnO NPs.Methods: RAECMs were exposed apically to ZnO NPs or, in some experiments, to culture fluid containing ZnCl2 or free Zn released from ZnO NPs. Transepithelial electrical resistance (R-T) and equivalent short-circuit current (I-EQ) were assessed as functions of concentration and time. Morphologic changes, lactate dehydrogenase release, cell membrane integrity, intracellular reactive oxygen species (ROS), and mitochondrial activity were measured.Measurements and Main Results: Apical exposure to 176 mu g/ml ZnO NPs decreased R-T and I-EQ of RAECMs by 100% over 24 hours, whereas exposure to 11 mu g/ml ZnO NPs had little effect. Changes in R-T and I-EQ caused by 176 mu g/ml ZnO NPs were irreversible. ZnO NP effects on R-T yielded half-maximal concentrations of approximately 20 mu g/ml. Apical exposure for 24 hours to 176 mu g/ml ZnO NPs induced decreases in mitochondrial activity and increases in lactate dehydrogenase release, permeability to fluorescein sulfonic acid, increased intracellular ROS, and translocation of ZnO NPs from apical to basolateral fluid (most likely across injured cells and/or damaged paracellular pathways).Conclusions: ZnO NPs cause severe injury to RAECMs in a dose-and time-dependent manner, mediated, at least in part, by free Zn released from ZnO NPs, mitochondrial dysfunction, and increased intracellular ROS.