Dynamics of podosome stiffness revealed by atomic force microscopy
Dynamics of podosome stiffness revealed by atomic force microscopy
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DOI：
10.1073/pnas.1007835107
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发表时间：
2010-12-07
影响因子：
11.1
通讯作者：
Charriere, Guillaume M.
中科院分区：
文献类型：
--
作者：
Labernadie, Anna;Thibault, Christophe;Charriere, Guillaume M.
足体是一种独特的细胞实体，专见于巨噬细胞，参与细胞-基质相互作用、基质降解和三维迁移。它们相当于F-肌动蛋白的核心，在其底部被基质受体包围。为了研究足体的结构/功能关系，采用软光刻、原子力显微镜(AFM)和相关荧光显微镜对人血单核细胞分化为巨噬细胞的足体物理性质进行了表征。足体的形成被限制在用微图案化的纤维蛋白原描绘的区域，以便于AFM分析。足体高度和硬度在活巨噬细胞(578+/-209 nm和43.8+/-9.3kpa)中测量得非常准确，这些物理特性与底层基质的性质无关。此外，延时原子力显微镜显示，足细胞在其整个寿命内存在两种重叠的周期性硬度变化，这取决于F-肌动蛋白和肌球蛋白II的活性。这份报告表明，足体的生物物理性质是服从AFM的，使得在纳米尺度上研究活的巨噬细胞中的足体并分析它们的亲密动力学成为可能。这种方法为更好地理解足小体在生理和病理环境下的机械功能开辟了新的视角。
Podosomes are unique cellular entities specifically found in macrophages and involved in cell-matrix interactions, matrix degradation, and 3D migration. They correspond to a core of F-actin surrounded at its base by matrix receptors. To investigate the structure/function relationships of podosomes, soft lithography, atomic force microscopy (AFM), and correlative fluorescence microscopy were used to characterize podosome physical properties in macrophages differentiated from human blood monocytes. Podosome formation was restricted to delineated areas with micropatterned fibrinogen to facilitate AFM analyses. Podosome height and stiffness were measured with great accuracy in living macrophages (578 +/- 209 nm and 43.8 +/- 9.3 kPa) and these physical properties were independent of the nature of the underlying matrix. In addition, time-lapse AFM revealed that podosomes harbor two types of overlapping periodic stiffness variations throughout their lifespan, which depend on F-actin and myosin II activity. This report shows that podosome biophysical properties are amenable to AFM, allowing the study of podosomes in living macrophages at nanoscale resolution and the analysis of their intimate dynamics. Such an approach opens up perspectives to better understand the mechanical functionality of podosomes under physiological and pathological contexts.