Institute of Biophysics, University of Bremen, 28359 Bremen, Germany.
University of Lille, CNRS, INSERM, CHU Lille, Institute Pasteur Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, 59021 Lille, France.
Int J Mol Sci. 2023 Jan 20;24(3):2043. doi: 10.3390/ijms24032043.
Mechanical properties of healthy and Dupuytren fibroblasts were investigated by atomic force microscopy (AFM). In addition to standard force curves, rheological properties were assessed using an oscillatory testing methodology, in which the frequency was swept from 1 Hz to 1 kHz, and data were analyzed using the structural damping model. Dupuytren fibroblasts showed larger apparent Young's modulus values than healthy ones, which is in agreement with previous results. Moreover, cell mechanics were compared before and after ML-7 treatment, which is a myosin light chain kinase inhibitor (MLCK) that reduces myosin activity and hence cell contraction. We employed two different concentrations of ML-7 inhibitor and could observe distinct cell reactions. At 1 µM, healthy and scar fibroblasts did not show measurable changes in stiffness, but Dupuytren fibroblasts displayed a softening and recovery after some time. When increasing ML-7 concentration (3 µM), the majority of cells reacted, Dupuytren fibroblasts were the most susceptible, not being able to recover from the drug and dying. These results suggested that ML-7 is a potent inhibitor for MLCK and that myosin II is essential for cytoskeleton stabilization and cell survival.
采用原子力显微镜（AFM）研究健康和杜普伊特伦挛缩纤维的力学性能。除了标准的力曲线外，还使用振荡测试方法评估流变性能，在该方法中，频率从 1 Hz 扫到 1 kHz，并使用结构阻尼模型分析数据。杜普伊特伦挛缩纤维的表观杨氏模量值大于健康纤维，这与先前的结果一致。此外，在使用肌球蛋白轻链激酶抑制剂（MLCK）ML-7 处理前后比较细胞力学，该抑制剂可降低肌球蛋白活性，从而减少细胞收缩。我们使用了两种不同浓度的 ML-7 抑制剂，观察到了不同的细胞反应。在 1 μM 时，健康和疤痕成纤维细胞的硬度没有可测量的变化，但杜普伊特伦挛缩纤维在一段时间后表现出软化和恢复。当增加 ML-7 浓度（3 μM）时，大多数细胞都发生了反应，杜普伊特伦挛缩纤维最敏感，不能从药物中恢复并死亡。这些结果表明，ML-7 是 MLCK 的有效抑制剂，肌球蛋白 II 对于细胞骨架稳定和细胞存活至关重要。
