捲曲型態對細胞牽引力的效果

Abstract

在高度動態的組織，例如肌腱、韌帶和血管壁中，膠原蛋白束會形成稱為crimp的波紋狀結構。這些組織中的細胞也會有波紋狀型態。然而，目前波紋狀形態如何影響細胞張力並不清楚。在這項研究中，我們設計體外模型系統，使用在聚丙烯酰胺凝膠上之微壓印技術，來模擬可硬度控制的波紋狀微環境。細胞牽引力顯微術 (traction force microscopy, TFM) 顯示，於人類間葉幹細胞中，波紋狀比起直線的細胞，有更強的細胞牽引力。此外，軟性基材使得細胞對波紋與直線型態的效應變得敏感。我們的結果揭示了波紋狀形態對細胞張力具有單獨於肌凝蛋白-II收縮力以外的影響。

In highly dynamic tissues like tendons, ligaments and vascular walls, extracellular collagen bundles form wavy structures, known as crimp. Cells embedded in these tissues develop wavy morphology. However, how the wavy morphology influence cell behaviors, such as tension, is mostly unknown. In this study, we designed an in vitro model system using microcontact printing on polyacrylamide gel to mimic the wavy microenvironments with controllable substrate stiffness. Traction force microscopy (TFM) showed that crimp induced more cell traction forces in human mesenchymal stem cells (hMSCs) compared with straight cells. Interestingly, this increase is myosin-II-independent. Moreover, softer substrate sensitized the response to the wavy shape, such as cell spreading area and focal adhesions. Our results revealed myosin-II-contractility independent effects of wavy morphology on cell tension.