A new microrheometric approach reveals individual and cooperative roles for TGF-β1 and IL-1β in fibroblast-mediated stiffening of collagen gels
A new microrheometric approach reveals individual and cooperative roles for TGF-β1 and IL-1β in fibroblast-mediated stiffening of collagen gels
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DOI：
10.1096/fj.06-7510com
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发表时间：
2007-07-01
期刊：
影响因子：
4.8
通讯作者：
Tschumperlin, Daniel J.
中科院分区：
文献类型：
--
作者：
Leung, Lester Y.;Tian, David;Tschumperlin, Daniel J.
细胞外基质的硬度可以深刻地影响细胞和组织的行为。因此，有一个新兴的重点是了解矩阵机械环境是如何建立，调节和修改。在这里，我们开发了一种显微流变学测定来测量模型细胞外基质（I型胶原蛋白凝胶）的机械性能，并使用它来探索姜黄素诱导的，细胞介导的基质机械性能的变化。微流变学测定使用在原纤维形成期间嵌入胶原凝胶内的微米级铁磁珠。将珠子磁化，然后使其经受扭转场，通过磁力计测量珠子的总旋转。珠旋转的程度反映了周围基质的刚度。我们表明，微尺度测定胶原蛋白凝胶的刚度措施与标准的宏观流变学。为了证明该测定法在生物学发现中的实用性，我们测量了在2至14天内暴露于三种浓度的六种细胞因子的成纤维细胞填充的胶原凝胶的硬度变化。在测试的细胞因子中，转化生长因子-β 1和白细胞介素-1 β增强基质硬度，并共同对基质力学的细胞调节产生协同作用。在这里开发的显微流变学方法应该加速发现的生物途径编排细胞调制矩阵力学。
The stiffness of the extracellular matrix can profoundly influence cell and tissue behaviors. Thus there is an emerging emphasis on understanding how matrix mechanical environments are established, regulated, and modified. Here we develop a microrheometric assay to measure the mechanical properties of a model extracellular matrix (type I collagen gel) and use it to explore cytokine-induced, cell-mediated changes in matrix mechanical properties. The microrheometric assay uses micron-scale ferrimagnetic beads embedded within collagen gels during fibrillogenesis. The beads are magnetized, then subjected to a twisting field, with the aggregate rotation of the beads measured by a magnetometer. The degree of bead rotation reflects the stiffness of the surrounding matrix. We show that the microscale assay provides stiffness measures for collagen gels comparable to those obtained with standard macroscale rheometry. To demonstrate the utility of the assay for biological discovery, we measure stiffness changes in fibroblast-populated collagen gels exposed to three concentrations of six cytokines over 2 to 14 days. Among the cytokines tested, transforming growth factor-beta 1 and interleukin-1 beta enhanced matrix stiffness, and together exerted cooperative effects on cellular modulation of matrix mechanics. The microrheometry approach developed here should accelerate the discovery of biological pathways orchestrating cellular modulation of matrix mechanics.