Probing cellular response to topography in three dimensions.
Probing cellular response to topography in three dimensions.
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DOI：
10.1016/j.biomaterials.2019.01.009
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发表时间：
2019-01
期刊：
影响因子：
14
通讯作者：
C. Paul;Alex M. Hruska;J. Staunton;Hannah A. Burr;K. Daly;Jiyun Kim;N. Jiang;K. Tanner
中科院分区：
文献类型：
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作者：
C. Paul;Alex M. Hruska;J. Staunton;Hannah A. Burr;K. Daly;Jiyun Kim;N. Jiang;K. Tanner
体内组织微环境的生物物理方面包括微观机械特性、原纤维排列以及细胞外基质 (ECM) 的结构或形貌。这些方面与来自无数不同 ECM 蛋白的化学信号协同作用，提供驱动细胞反应的线索。在这里，我们采用自下而上的方法，利用磁场驱动的顺磁性胶体颗粒组装，将纤维结构构建成 3D 无定形水凝胶，这些顺磁性胶体颗粒与体内发现的三种类型的人类 ECM 蛋白功能化。我们研究了在由相同大小的原纤维组成并以相似的几何形状排列的基质中培养的细胞对于每种测试的 ECM 蛋白是否会表现出相似的行为。我们能够解决排列纤维附近微观机械性能的空间异质性，而这在体组织力学中未观察到。然后，我们使用该平台来检查有助于细胞排列的因素，以响应富含层粘连蛋白的 3D 基质中的地形提示。多个人类细胞系优先在平行或垂直于排列纤维的方向上延伸突起，与 ECM 涂层无关。通过桩蛋白定位测量，焦点粘附蛋白主要弥散在细胞质中，很少有斑点位于突起处。整合素 β1 和肌成束蛋白调节突出延伸，但不调节突出对齐。肌球蛋白 II 抑制不会减少观察到的突出长度。相反，当在具有排列纤维的水凝胶中培养时，肌球蛋白 II 活性降低的细胞会产生随机方向的突起。同样，在体内观察到肌球蛋白 II 依赖性，用肌球蛋白 II 治疗后，细胞不再沿着血管近腔表面排列。这些数据表明，肌球蛋白 II 可以调节正常细胞和转化细胞的 3D 工程基质中的形貌感知。
Biophysical aspects of in vivo tissue microenvironments include microscale mechanical properties, fibrillar alignment, and architecture or topography of the extracellular matrix (ECM). These aspects act in concert with chemical signals from a myriad of diverse ECM proteins to provide cues that drive cellular responses. Here, we used a bottom-up approach to build fibrillar architecture into 3D amorphous hydrogels using magnetic-field driven assembly of paramagnetic colloidal particles functionalized with three types of human ECM proteins found in vivo. We investigated if cells cultured in matrices comprised of fibrils of the same size and arranged in similar geometries will show similar behavior for each of the ECM proteins tested. We were able to resolve spatial heterogeneities in microscale mechanical properties near aligned fibers that were not observed in bulk tissue mechanics. We then used this platform to examine factors contributing to cell alignment in response to topographical cues in 3D laminin-rich matrices. Multiple human cell lines extended protrusions preferentially in directions parallel or perpendicular to aligned fibers independently of the ECM coating. Focal adhesion proteins, as measured by paxillin localization, were mainly diffuse in the cytoplasm, with few puncta localized at the protrusions. Integrin β1 and fascin regulated protrusion extension but not protrusion alignment. Myosin II inhibition did not reduce observed protrusion length. Instead, cells with reduced myosin II activity generated protrusions in random orientations when cultured in hydrogels with aligned fibers. Similarly, myosin II dependence was observed in vivo, where cells no longer aligned along the abluminal surfaces of blood vessels upon treatment with blebbistatin. These data suggest that myosin II can regulate sensing of topography in 3D engineered matrices for both normal and transformed cells.