Zhang Min, Chen Fa-Ming, Chen Yong-Jin, Wu Shun, Lv Xin, Zhao Rui-Ni
Department of General Dentistry and Emergency, School of Stomatology, The Fourth Military Medical University, Xi'an, Shanxi 710032, PR China.
Mol Cell Biomech. 2011 Mar;8(1):43-60.
To investigate the role of mechanical pressure on cartilage thickness and type II collagen synthesis, and the role of G protein in that process, in vitro organ culture of mandibular cartilage was adopted in this study. A hydraulic pressure-controlled cellular strain unit was used to apply hydrostatic pressurization to explant cultures. The explants were compressed by different pressure values (0 kPa, 100 kPa, and 300 kPa) after pretreatment with or without a selective and direct antagonist (NF023) for the G proteins. After 4, 8 and 12 h of cell culture under each pressure condition, histological sections of the explants were stained with hematoxylin-eosin to investigate the thickness of the cartilage. Immunohistochemical staining was used to observe type II collagen expressions. The results showed that a hydrostatic pressure of 100 kPa significantly reduced the thickness of the proliferative layer in condylar cartilage without affecting the thickness of the transitional layer. Hydrostatic pressures of 100 kPa and 300 kPa significantly enhanced the synthesis of type II collagen. G proteins are involved not only in the proliferation and differentiation of condylar cartilage regulated by prolonged pressure, but also in the process of collagen production in condylar cartilage stimulated by pressure.
为研究机械压力对软骨厚度及Ⅱ型胶原合成的作用，以及G蛋白在此过程中的作用，本研究采用下颌软骨体外器官培养。使用液压控制细胞应变装置对组织块培养物施加静水压力。在用或不用G蛋白选择性直接拮抗剂（NF023）预处理后，将组织块用不同压力值（0 kPa、100 kPa和300 kPa）进行压缩。在每种压力条件下细胞培养4、8和12小时后，将组织块的组织学切片用苏木精-伊红染色以研究软骨厚度。采用免疫组织化学染色观察Ⅱ型胶原表达。结果显示，100 kPa的静水压力显著降低髁突软骨增殖层厚度，而不影响过渡层厚度。100 kPa和300 kPa的静水压力显著增强Ⅱ型胶原合成。G蛋白不仅参与长期压力调节的髁突软骨增殖和分化，还参与压力刺激的髁突软骨胶原产生过程。
