Zhou Yimei, Guo Yutong, Zhang Mei, Quan Shuqi, Li Juan
State Key Laboratory of Oral Diseases, National Center of Stomatology, West China Hospital of Stomatology, National Clinical Research Center for Oral Diseases, Sichuan University, 14#, 3rd Section, Renmin South Road, Chengdu, 610041, China.
Department of Orthodontics, National Center for Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health, Beijing, 100081, PR China.
J Mol Histol. 2025 Feb 4;56(2):79. doi: 10.1007/s10735-025-10362-1.
The extracellular matrix guides cell behavior through mechanical properties, which plays a role in determining cell function and can even influence stem cell fate. Compared with adherent culture, the three-dimensional culture environment is closer to the growth conditions in vivo, but is limited by standardization of material properties and observation and measurement methods. Therefore, it is necessary to study the relationship among the three-dimensional morphological characteristics of cells, cytoskeleton, and stem cell differentiation under adherent culture conditions. Here, we control the cell volume by adjusting the cell density, microfilament cytoskeleton tension, and osmotic pressure of the culture environment, and analyze the cell morphological features and differentiation to the osteoblastic and adipogenic lineages. Based on the in vitro and in vivo results, we identify cell volume as the true reflection of the cytoskeleton tension under stress stimuli compared with cell spreading area. By adjusting cell volume, cytoskeletal tension and cell differentiation can be regulated without affecting cell spreading area. Further study shows that the Ras-related small GTPase RAP2 inhibits the activity of mechanical transducers Lamin A/C and YAP1, playing an important role in cell volume regulation of cell differentiation. In summary, our results support the close relationship between cell volume and cytoskeleton tension. The regulatory role of cell volume on cell differentiation is modulated, at least in part, by RAP2-related mechanosensitive pathways. Our insights into how cell volume regulates cell differentiation may build a bridge between two-dimensional and three-dimensional mechanical studies in cell biology.
细胞外基质通过机械特性引导细胞行为，这在决定细胞功能甚至影响干细胞命运方面发挥着作用。与贴壁培养相比，三维培养环境更接近体内生长条件，但受到材料特性标准化以及观察和测量方法的限制。因此，有必要研究贴壁培养条件下细胞的三维形态特征、细胞骨架与干细胞分化之间的关系。在此，我们通过调节细胞密度、微丝细胞骨架张力和培养环境的渗透压来控制细胞体积，并分析细胞形态特征以及向成骨和成脂谱系的分化情况。基于体外和体内实验结果，我们发现与细胞铺展面积相比，细胞体积是应激刺激下细胞骨架张力的真实反映。通过调节细胞体积，可以在不影响细胞铺展面积的情况下调节细胞骨架张力和细胞分化。进一步研究表明，Ras相关小GTP酶RAP2抑制机械转导蛋白Lamin A/C和YAP1的活性，在细胞分化的细胞体积调节中起重要作用。总之，我们的结果支持细胞体积与细胞骨架张力之间的密切关系。细胞体积对细胞分化的调节作用至少部分是由与RAP2相关的机械敏感通路介导的。我们对细胞体积如何调节细胞分化的见解可能会在细胞生物学的二维和三维力学研究之间架起一座桥梁。
