A murine scavenger receptor MARCO recognizes polystyrene nanoparticles
A murine scavenger receptor MARCO recognizes polystyrene nanoparticles
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DOI：
10.1093/toxsci/kfm050
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发表时间：
2007-06-01
影响因子：
3.8
通讯作者：
Hirano, Seishiro
中科院分区：
文献类型：
--
作者：
Kanno, Sanae;Furuyama, Akiko;Hirano, Seishiro
最近的毒理学研究表明，纳米颗粒或超细颗粒(<；100 nm)比细颗粒(<；2微米)毒性更大，因为它们的表面积更大。众所周知，肺泡巨噬细胞在抵御各种环境颗粒物和微生物的第一道屏障中发挥着重要作用。这是通过与具有胶原性结构的巨噬细胞受体(MARCO)结合实现的，MARCO是表达在巨噬细胞细胞表面的几种清道夫类型受体之一。Marco已被证明可以调节未调理的环境颗粒的摄取，如二氧化钛和三氧化二铁(直径1.3微米)。然而，对细胞对纳米颗粒的摄取知之甚少。在目前的研究中，我们研究了Marco是否通过使用荧光标记的聚苯乙烯颗粒(直径分别为20 nm、200 nm和1微米)来调节纳米颗粒的吸收。将Marco基因和空载体分别导入COS-7细胞，通过荧光显微镜和原子力显微镜观察颗粒与细胞的结合情况。Marco转染组细胞与三种大小的颗粒均呈时间依赖性结合，而空载体转染组在5h后未见明显的颗粒结合。多聚G可部分抑制Marco转基因细胞对颗粒的摄取。这些结果表明，巨噬细胞至少部分地通过Marco与纳米颗粒(20 Nm)结合，并且Marco在清除沉积在肺泡区的纳米颗粒方面发挥了作用。
Recent toxicological studies indicate that nanoparticles or ultrafine particles (< 100 nm) are more toxic than fine particles (< 2 mu m) because of their greater surface area. It is well known that alveolar macrophages play an important role in the first defense against various environmental particles and microorganisms. This is accomplished by binding to a macrophage receptor with collagenous structure (MARCO), one of several scavenger-type receptors expressed on the cell surface of macrophages. MARCO has been shown to mediate the ingestion of unopsonized environmental particles such as TiO2 and Fe2O3 (1.3 mu m in diameter). However, very little is known about the cellular uptake of nanoparticles. In the present study, we investigated whether MARCO mediates the uptake of nanoparticles by using fluorescent-tagged polystyrene particles (20 nm, 200 nm, and 1 mu m in diameter). COS-7 cells were transfected with either MARCO cDNA or an empty vector, and the association of the particles with the cells were observed by fluorescence microscopy and atomic force microscopy. MARCO-transfected cells associated with all three sizes of particles in a time-dependent manner, while no obvious binding of particles occurred after 5 h to the empty vector-transfected cells. The uptake of particles by MARCO-transfected cells was partially inhibited by polyG. These results suggest that macrophages associate with nanoparticles (20 nm) at least in part through MARCO and that MARCO plays a role in clearing nanoparticles which can deposit in the alveolar region.