Despite the vital role of mechanical forces in biology, it still remains a challenge to image cellular force with sub-100-nm resolution. Here, we present tension points accumulation for imaging in nanoscale topography (tPAINT), integrating molecular tension probes with the DNA points accumulation for imaging in nanoscale topography (DNA-PAINT) technique to map piconewton mechanical events with ~25-nm resolution. To perform live-cell dynamic tension imaging, we engineered reversible probes with a cryptic docking site revealed only when the probe experiences forces exceeding a defined mechanical threshold (~7–21 pN). Additionally, we report a second type of irreversible tPAINT probe that exposes its cryptic docking site permanently and thus integrates force history over time, offering improved spatial resolution in exchange for temporal dynamics. We applied both types of tPAINT probes to map integrin receptor forces in live human platelets and mouse embryonic fibroblasts. Importantly, tPAINT revealed a link between platelet forces at the leading edge of cells and the dynamic actin-rich ring nucleated by the Arp2/3 complex.

尽管机械力在生物学中发挥着至关重要的作用，但以亚 100 nm 分辨率对细胞力进行成像仍然是一个挑战。在这里，我们提出了用于纳米级形貌成像（tPAINT）的张力点积累，将分子张力探针与用于纳米级形貌成像（DNA-PAINT）技术的DNA点积累相结合，以约25纳米的分辨率绘制皮牛顿力学事件。为了进行活细胞动态张力成像，我们设计了可逆探针，其神秘的对接位点只有当探针受到的力超过定义的机械阈值（~7-21 pN）时才会显露出来。此外，我们报告了第二种类型的不可逆 tPAINT 探针，它永久暴露其神秘的对接位点，从而随着时间的推移整合力的历史，提供改进的空间分辨率以换取时间动态。我们应用两种类型的 tPAINT 探针来绘制活人血小板和小鼠胚胎成纤维细胞中的整合素受体力图。重要的是，tPAINT 揭示了细胞前缘的血小板力与 Arp2/3 复合物成核的动态富含肌动蛋白的环之间的联系。