Zhang Qiao, Tamashunas Andrew C, Lele Tanmay P
Department of Chemical Engineering, University of Florida.
Department of Chemical Engineering, University of Florida;
J Vis Exp. 2018 Jul 29(137):58038. doi: 10.3791/58038.
The mechanical properties of the nucleus determine its response to mechanical forces generated in cells. Because the nucleus is molecularly continuous with the cytoskeleton, methods are needed to probe its mechanical behavior in adherent cells. Here, we discuss the direct force probe (DFP) as a tool to apply force directly to the nucleus in a living adherent cell. We attach a narrow micropipette to the nuclear surface with suction. The micropipette is translated away from the nucleus, which causes the nucleus to deform and translate. When the restoring force is equal to the suction force, the nucleus detaches and elastically relaxes. Because the suction pressure is precisely known, the force on the nuclear surface is known. This method has revealed that nano-scale forces are sufficient to deform and translate the nucleus in adherent cells, and identified cytoskeletal elements that enable the nucleus to resist forces. The DFP can be used to dissect the contributions of cellular and nuclear components to nuclear mechanical properties in living cells.
细胞核的力学性质决定了其对细胞内产生的机械力的响应。由于细胞核与细胞骨架在分子层面是连续的，因此需要一些方法来探究其在贴壁细胞中的力学行为。在这里，我们讨论直接力探针（DFP）作为一种在活的贴壁细胞中直接对细胞核施加力的工具。我们通过吸力将一个细的微量移液器附着在细胞核表面。微量移液器从细胞核移开，这会导致细胞核变形并移动。当恢复力等于吸力时，细胞核分离并弹性松弛。由于吸力压力是精确已知的，所以细胞核表面的力是已知的。该方法表明，纳米级的力足以使贴壁细胞中的细胞核变形和移动，并确定了使细胞核能够抵抗外力的细胞骨架成分。DFP可用于剖析细胞和细胞核成分对活细胞中细胞核力学性质的贡献。
